diff --git a/src/Makefile.am b/src/Makefile.am
index f7692e26ab..2e842fccbc 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,716 +1,717 @@
 # Copyright (c) 2013-2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 DIST_SUBDIRS = secp256k1 univalue
 
 AM_LDFLAGS = $(PTHREAD_CFLAGS) $(LIBTOOL_LDFLAGS) $(HARDENED_LDFLAGS) $(GPROF_LDFLAGS) $(SANITIZER_LDFLAGS)
 AM_CXXFLAGS = $(DEBUG_CXXFLAGS) $(HARDENED_CXXFLAGS) $(WARN_CXXFLAGS) $(NOWARN_CXXFLAGS) $(ERROR_CXXFLAGS) $(GPROF_CXXFLAGS) $(SANITIZER_CXXFLAGS)
 AM_CPPFLAGS = $(DEBUG_CPPFLAGS) $(HARDENED_CPPFLAGS)
 AM_LIBTOOLFLAGS = --preserve-dup-deps
 EXTRA_LIBRARIES =
 
 if EMBEDDED_UNIVALUE
 LIBUNIVALUE = univalue/libunivalue.la
 
 $(LIBUNIVALUE): $(wildcard univalue/lib/*) $(wildcard univalue/include/*)
 	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) -C $(@D) $(@F)
 else
 LIBUNIVALUE = $(UNIVALUE_LIBS)
 endif
 
 BITCOIN_INCLUDES=-I$(builddir) $(BDB_CPPFLAGS) $(BOOST_CPPFLAGS) $(LEVELDB_CPPFLAGS) $(CRYPTO_CFLAGS) $(SSL_CFLAGS)
 
 BITCOIN_INCLUDES += -I$(srcdir)/secp256k1/include
 BITCOIN_INCLUDES += $(UNIVALUE_CFLAGS)
 
 BITCOIN_SEEDER_INCLUDES = -I$(srcdir)/seeder
 BITCOIN_SEEDER_INCLUDES += $(BITCOIN_INCLUDES)
 
 LIBBITCOIN_SERVER=libbitcoin_server.a
 LIBBITCOIN_COMMON=libbitcoin_common.a
 LIBBITCOIN_CONSENSUS=libbitcoin_consensus.a
 LIBBITCOIN_CLI=libbitcoin_cli.a
 LIBBITCOIN_UTIL=libbitcoin_util.a
 LIBBITCOIN_CRYPTO_BASE=crypto/libbitcoin_crypto_base.a
 LIBBITCOINQT=qt/libbitcoinqt.a
 LIBSECP256K1=secp256k1/libsecp256k1.la
 
 if ENABLE_ZMQ
 LIBBITCOIN_ZMQ=libbitcoin_zmq.a
 endif
 if BUILD_BITCOIN_LIBS
 LIBBITCOINCONSENSUS=libbitcoinconsensus.la
 endif
 if BUILD_BITCOIN_SEEDER
 LIBBITCOIN_SEEDER=libbitcoin_seeder.a
 endif
 if ENABLE_WALLET
 LIBBITCOIN_WALLET=libbitcoin_wallet.a
 endif
 
 LIBBITCOIN_CRYPTO= $(LIBBITCOIN_CRYPTO_BASE)
 if ENABLE_SSE41
 LIBBITCOIN_CRYPTO_SSE41 = crypto/libbitcoin_crypto_sse41.a
 LIBBITCOIN_CRYPTO += $(LIBBITCOIN_CRYPTO_SSE41)
 endif
 if ENABLE_AVX2
 LIBBITCOIN_CRYPTO_AVX2 = crypto/libbitcoin_crypto_avx2.a
 LIBBITCOIN_CRYPTO += $(LIBBITCOIN_CRYPTO_AVX2)
 endif
 if ENABLE_SHANI
 LIBBITCOIN_CRYPTO_SHANI = crypto/libbitcoin_crypto_shani.a
 LIBBITCOIN_CRYPTO += $(LIBBITCOIN_CRYPTO_SHANI)
 endif
 
 $(LIBSECP256K1): $(wildcard secp256k1/src/*) $(wildcard secp256k1/include/*)
 	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) -C $(@D) $(@F)
 
 # Make is not made aware of per-object dependencies to avoid limiting building parallelization
 # But to build the less dependent modules first, we manually select their order here:
 EXTRA_LIBRARIES += \
   $(LIBBITCOIN_CRYPTO) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_COMMON) \
   $(LIBBITCOIN_CONSENSUS) \
   $(LIBBITCOIN_SERVER) \
   $(LIBBITCOIN_CLI) \
   $(LIBBITCOIN_SEEDER) \
   $(LIBBITCOIN_WALLET) \
   $(LIBBITCOIN_ZMQ)
 
 lib_LTLIBRARIES = $(LIBBITCOINCONSENSUS)
 
 bin_PROGRAMS =
 noinst_PROGRAMS =
 TESTS =
 BENCHMARKS =
 
 if BUILD_BITCOIND
   bin_PROGRAMS += bitcoind
 endif
 
 if BUILD_BITCOIN_SEEDER
   bin_PROGRAMS += bitcoin-seeder
 endif
 
 if BUILD_BITCOIN_UTILS
   bin_PROGRAMS += bitcoin-cli bitcoin-tx
 endif
 
 .PHONY: FORCE check-symbols check-security
 # bitcoin core #
 BITCOIN_CORE_H = \
   addrdb.h \
   addrman.h \
   attributes.h \
   avalanche.h \
   banman.h \
   base58.h \
   bloom.h \
   blockencodings.h \
   blockfileinfo.h \
   blockfilter.h \
   blockindexworkcomparator.h \
   blockstatus.h \
   blockvalidity.h \
   cashaddr.h \
   cashaddrenc.h \
   chain.h \
   chainparams.h \
   chainparamsbase.h \
   chainparamsconstants.h \
   chainparamsseeds.h \
   checkpoints.h \
   checkqueue.h \
   clientversion.h \
   coins.h \
   compat.h \
   compat/assumptions.h \
   compat/byteswap.h \
   compat/endian.h \
   compat/sanity.h \
   compat/setenv.h \
   compressor.h \
   config.h \
   consensus/activation.h \
   consensus/consensus.h \
   consensus/tx_verify.h \
   core_io.h \
   core_memusage.h \
   cuckoocache.h \
   flatfile.h \
   fs.h \
   globals.h \
   httprpc.h \
   httpserver.h \
   index/base.h \
   index/txindex.h \
   indirectmap.h \
   init.h \
   interfaces/chain.h \
   interfaces/handler.h \
   interfaces/node.h \
   interfaces/wallet.h \
   key.h \
   key_io.h \
   keystore.h \
   dbwrapper.h \
   limitedmap.h \
   logging.h \
   memusage.h \
   merkleblock.h \
   miner.h \
   minerfund.h \
   net.h \
   net_processing.h \
   netaddress.h \
   netbase.h \
   netmessagemaker.h \
   noui.h \
+  optional.h \
   outputtype.h \
   policy/fees.h \
   policy/mempool.h \
   policy/policy.h \
   pow.h \
   protocol.h \
   radix.h \
   random.h \
   rcu.h \
   reverse_iterator.h \
   reverselock.h \
   rpc/blockchain.h \
   rpc/client.h \
   rpc/command.h \
   rpc/jsonrpcrequest.h \
   rpc/mining.h \
   rpc/protocol.h \
   rpc/rawtransaction.h \
   rpc/server.h \
   rpc/register.h \
   rpc/util.h \
   rwcollection.h \
   scheduler.h \
   script/descriptor.h \
   script/ismine.h \
   script/scriptcache.h \
   script/sigcache.h \
   script/sign.h \
   script/standard.h \
   shutdown.h \
   streams.h \
   support/allocators/secure.h \
   support/allocators/zeroafterfree.h \
   support/cleanse.h \
   support/events.h \
   support/lockedpool.h \
   sync.h \
   threadsafety.h \
   threadinterrupt.h \
   timedata.h \
   torcontrol.h \
   txdb.h \
   txmempool.h \
   ui_interface.h \
   undo.h \
   util/bitmanip.h \
   util/bytevectorhash.h \
   util/moneystr.h \
   util/system.h \
   util/threadnames.h \
   util/time.h \
   validation.h \
   validationinterface.h \
   versionbits.h \
   versionbitsinfo.h \
   walletinitinterface.h \
   wallet/coincontrol.h \
   wallet/coinselection.h \
   wallet/crypter.h \
   wallet/db.h \
   wallet/finaltx.h \
   wallet/rpcdump.h \
   wallet/fees.h \
   wallet/rpcwallet.h \
   wallet/wallet.h \
   wallet/walletdb.h \
   wallet/walletutil.h \
   warnings.h \
   zmq/zmqabstractnotifier.h \
   zmq/zmqconfig.h\
   zmq/zmqnotificationinterface.h \
   zmq/zmqpublishnotifier.h \
   zmq/zmqrpc.h
 
 
 obj/build.h: FORCE
 	@$(MKDIR_P) "$(builddir)/obj"
 	@$(top_srcdir)/share/genbuild.sh "$(abs_top_builddir)/src/obj/build.h" \
 	  "$(abs_top_srcdir)"
 libbitcoin_util_a-clientversion.$(OBJEXT): obj/build.h
 
 # server: shared between bitcoind and bitcoin-qt
 libbitcoin_server_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(MINIUPNPC_CPPFLAGS) $(EVENT_CFLAGS) $(EVENT_PTHREADS_CFLAGS)
 libbitcoin_server_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_server_a_SOURCES = \
   addrdb.cpp \
   addrman.cpp \
   avalanche.cpp \
   banman.cpp \
   bloom.cpp \
   blockencodings.cpp \
   blockfilter.cpp \
   chain.cpp \
   checkpoints.cpp \
   config.cpp \
   consensus/activation.cpp \
   consensus/tx_verify.cpp \
   flatfile.cpp \
   globals.cpp \
   httprpc.cpp \
   httpserver.cpp \
   index/base.cpp \
   index/txindex.cpp \
   init.cpp \
   interfaces/chain.cpp \
   interfaces/handler.cpp \
   interfaces/node.cpp \
   dbwrapper.cpp \
   merkleblock.cpp \
   miner.cpp \
   minerfund.cpp \
   net.cpp \
   net_processing.cpp \
   noui.cpp \
   outputtype.cpp \
   policy/fees.cpp \
   policy/mempool.cpp \
   policy/policy.cpp \
   pow.cpp \
   rest.cpp \
   rpc/abc.cpp \
   rpc/avalanche.cpp \
   rpc/blockchain.cpp \
   rpc/command.cpp \
   rpc/jsonrpcrequest.cpp \
   rpc/mining.cpp \
   rpc/misc.cpp \
   rpc/net.cpp \
   rpc/rawtransaction.cpp \
   rpc/server.cpp \
   script/scriptcache.cpp \
   script/sigcache.cpp \
   shutdown.cpp \
   timedata.cpp \
   torcontrol.cpp \
   txdb.cpp \
   txmempool.cpp \
   ui_interface.cpp \
   validation.cpp \
   validationinterface.cpp \
   versionbits.cpp \
   $(BITCOIN_CORE_H)
 
 if !ENABLE_WALLET
 libbitcoin_server_a_SOURCES += dummywallet.cpp
 endif
 
 if ENABLE_ZMQ
 libbitcoin_zmq_a_CPPFLAGS = $(BITCOIN_INCLUDES) $(ZMQ_CFLAGS)
 libbitcoin_zmq_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_zmq_a_SOURCES = \
   zmq/zmqabstractnotifier.cpp \
   zmq/zmqnotificationinterface.cpp \
   zmq/zmqpublishnotifier.cpp \
   zmq/zmqrpc.cpp
 endif
 
 
 # wallet: shared between bitcoind and bitcoin-qt, but only linked
 # when wallet enabled
 libbitcoin_wallet_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_wallet_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_wallet_a_SOURCES = \
   interfaces/wallet.cpp \
   wallet/coincontrol.cpp \
   wallet/crypter.cpp \
   wallet/coinselection.cpp \
   wallet/db.cpp \
   wallet/finaltx.cpp \
   wallet/fees.cpp \
   wallet/init.cpp \
   wallet/rpcdump.cpp \
   wallet/rpcwallet.cpp \
   wallet/wallet.cpp \
   wallet/walletdb.cpp \
   wallet/walletutil.cpp \
   $(BITCOIN_CORE_H)
 
 # crypto primitives library
 crypto_libbitcoin_crypto_base_a_CPPFLAGS = $(AM_CPPFLAGS)
 crypto_libbitcoin_crypto_base_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 crypto_libbitcoin_crypto_base_a_SOURCES = \
   crypto/aes.cpp \
   crypto/aes.h \
   crypto/chacha20.h \
   crypto/chacha20.cpp \
   crypto/common.h \
   crypto/hmac_sha256.cpp \
   crypto/hmac_sha256.h \
   crypto/hmac_sha512.cpp \
   crypto/hmac_sha512.h \
   crypto/ripemd160.cpp \
   crypto/ripemd160.h \
   crypto/sha1.cpp \
   crypto/sha1.h \
   crypto/sha256.cpp \
   crypto/sha256.h \
   crypto/sha512.cpp \
   crypto/sha512.h \
   crypto/siphash.cpp \
   crypto/siphash.h
 
 if USE_ASM
 crypto_libbitcoin_crypto_base_a_SOURCES += crypto/sha256_sse4.cpp
 endif
 
 crypto_libbitcoin_crypto_sse41_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 crypto_libbitcoin_crypto_sse41_a_CPPFLAGS = $(AM_CPPFLAGS)
 crypto_libbitcoin_crypto_sse41_a_CXXFLAGS += $(SSE41_CXXFLAGS)
 crypto_libbitcoin_crypto_sse41_a_CPPFLAGS += -DENABLE_SSE41
 crypto_libbitcoin_crypto_sse41_a_SOURCES = crypto/sha256_sse41.cpp
 
 crypto_libbitcoin_crypto_avx2_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 crypto_libbitcoin_crypto_avx2_a_CPPFLAGS = $(AM_CPPFLAGS)
 crypto_libbitcoin_crypto_avx2_a_CXXFLAGS += $(AVX2_CXXFLAGS)
 crypto_libbitcoin_crypto_avx2_a_CPPFLAGS += -DENABLE_AVX2
 crypto_libbitcoin_crypto_avx2_a_SOURCES = crypto/sha256_avx2.cpp
 
 crypto_libbitcoin_crypto_shani_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 crypto_libbitcoin_crypto_shani_a_CPPFLAGS = $(AM_CPPFLAGS)
 crypto_libbitcoin_crypto_shani_a_CXXFLAGS += $(SHANI_CXXFLAGS)
 crypto_libbitcoin_crypto_shani_a_CPPFLAGS += -DENABLE_SHANI
 crypto_libbitcoin_crypto_shani_a_SOURCES = crypto/sha256_shani.cpp
 
 # consensus: shared between all executables that validate any consensus rules.
 libbitcoin_consensus_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_consensus_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_consensus_a_SOURCES = \
   amount.h \
   arith_uint256.cpp \
   arith_uint256.h \
   consensus/merkle.cpp \
   consensus/merkle.h \
   consensus/params.h \
   consensus/validation.h \
   feerate.h \
   hash.cpp \
   hash.h \
   prevector.h \
   primitives/block.cpp \
   primitives/block.h \
   primitives/transaction.cpp \
   primitives/transaction.h \
   primitives/txid.h \
   pubkey.cpp \
   pubkey.h \
   script/bitcoinconsensus.cpp \
   script/bitfield.cpp \
   script/bitfield.h \
   script/sighashtype.h \
   script/interpreter.cpp \
   script/interpreter.h \
   script/script.cpp \
   script/script.h \
   script/script_error.cpp \
   script/script_error.h \
   script/script_flags.h \
   script/script_metrics.h \
   script/sigencoding.cpp \
   script/sigencoding.h \
   serialize.h \
   span.h \
   tinyformat.h \
   uint256.cpp \
   uint256.h \
   util/strencodings.cpp \
   util/strencodings.h \
   version.h
 
 # common: shared between bitcoind, and bitcoin-qt and non-server tools
 libbitcoin_common_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_common_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_common_a_SOURCES = \
   amount.cpp \
   base58.cpp \
   cashaddr.cpp \
   cashaddrenc.cpp \
   chainparams.cpp \
   config.cpp \
   coins.cpp \
   compressor.cpp \
   feerate.cpp \
   globals.cpp \
   core_read.cpp \
   core_write.cpp \
   key.cpp \
   key_io.cpp \
   keystore.cpp \
   netaddress.cpp \
   netbase.cpp \
   protocol.cpp \
   scheduler.cpp \
   script/descriptor.cpp \
   script/ismine.cpp \
   script/sign.cpp \
   script/standard.cpp \
   versionbitsinfo.cpp \
   warnings.cpp \
   $(BITCOIN_CORE_H)
 
 # util: shared between all executables.
 # This library *must* be included to make sure that the glibc
 # backward-compatibility objects and their sanity checks are linked.
 libbitcoin_util_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_util_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_util_a_SOURCES = \
   support/lockedpool.cpp \
   chainparamsbase.cpp \
   clientversion.cpp \
   compat/glibc_sanity.cpp \
   compat/glibcxx_sanity.cpp \
   compat/strnlen.cpp \
   fs.cpp \
   logging.cpp \
   random.cpp \
   rcu.cpp \
   rpc/protocol.cpp \
   rpc/util.cpp \
   support/cleanse.cpp \
   sync.cpp \
   threadinterrupt.cpp \
   uint256.cpp \
   uint256.h \
   util/system.cpp \
   util/moneystr.cpp \
   util/strencodings.cpp \
   util/threadnames.cpp \
   util/time.cpp \
   util/bytevectorhash.cpp \
   $(BITCOIN_CORE_H)
 
 if GLIBC_BACK_COMPAT
 libbitcoin_util_a_SOURCES += compat/glibc_compat.cpp
 AM_LDFLAGS += $(COMPAT_LDFLAGS)
 endif
 
 # cli: shared between bitcoin-cli and bitcoin-qt
 libbitcoin_cli_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_cli_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_cli_a_SOURCES = \
   rpc/client.cpp \
   $(BITCOIN_CORE_H)
 
 # seeder library
 libbitcoin_seeder_a_CPPFLAGS = $(AM_CPPFLAGS) $(PIE_FLAGS) $(BITCOIN_SEEDER_INCLUDES)
 libbitcoin_seeder_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_seeder_a_SOURCES = \
   seeder/bitcoin.cpp \
   seeder/bitcoin.h \
   seeder/db.cpp \
   seeder/db.h \
   seeder/dns.cpp \
   seeder/dns.h \
   seeder/util.h
 
 nodist_libbitcoin_util_a_SOURCES = $(srcdir)/obj/build.h
 #
 
 # bitcoind binary #
 bitcoind_SOURCES = bitcoind.cpp
 bitcoind_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 bitcoind_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 bitcoind_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 if TARGET_WINDOWS
 bitcoind_SOURCES += bitcoind-res.rc
 endif
 
 bitcoind_LDADD = \
   $(LIBBITCOIN_SERVER) \
   $(LIBBITCOIN_WALLET) \
   $(LIBBITCOIN_SERVER) \
   $(LIBBITCOIN_COMMON) \
   $(LIBUNIVALUE) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_ZMQ) \
   $(LIBBITCOIN_CONSENSUS) \
   $(LIBBITCOIN_CRYPTO) \
   $(LIBLEVELDB) \
   $(LIBLEVELDB_SSE42) \
   $(LIBMEMENV) \
   $(LIBSECP256K1)
 
 bitcoind_LDADD += $(BOOST_LIBS) $(BDB_LIBS) $(SSL_LIBS) $(CRYPTO_LIBS) $(MINIUPNPC_LIBS) $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS) $(ZMQ_LIBS)
 
 # bitcoin-cli binary #
 bitcoin_cli_SOURCES = bitcoin-cli.cpp
 bitcoin_cli_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(EVENT_CFLAGS)
 bitcoin_cli_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 bitcoin_cli_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 if TARGET_WINDOWS
 bitcoin_cli_SOURCES += bitcoin-cli-res.rc
 endif
 
 bitcoin_cli_LDADD = \
   $(LIBBITCOIN_CLI) \
   $(LIBUNIVALUE) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_CRYPTO)
 
 bitcoin_cli_LDADD += $(BOOST_LIBS) $(SSL_LIBS) $(CRYPTO_LIBS) $(EVENT_LIBS)
 #
 
 # bitcoin-seeder binary #
 bitcoin_seeder_SOURCES = seeder/main.cpp
 bitcoin_seeder_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_SEEDER_INCLUDES)
 bitcoin_seeder_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 bitcoin_seeder_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 bitcoin_seeder_LDADD = \
   $(LIBBITCOIN_SEEDER) \
   $(LIBBITCOIN_COMMON) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_CRYPTO) \
   $(LIBBITCOIN_CONSENSUS)
 
 bitcoin_seeder_LDADD += $(BOOST_LIBS) $(CRYPTO_LIBS)
 #
 
 # bitcoin-tx binary #
 bitcoin_tx_SOURCES = bitcoin-tx.cpp
 bitcoin_tx_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 bitcoin_tx_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 bitcoin_tx_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 if TARGET_WINDOWS
 bitcoin_tx_SOURCES += bitcoin-tx-res.rc
 endif
 
 bitcoin_tx_LDADD = \
   $(LIBUNIVALUE) \
   $(LIBBITCOIN_COMMON) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_CONSENSUS) \
   $(LIBBITCOIN_CRYPTO) \
   $(LIBSECP256K1)
 
 bitcoin_tx_LDADD += $(BOOST_LIBS) $(CRYPTO_LIBS)
 #
 
 # bitcoinconsensus library #
 if BUILD_BITCOIN_LIBS
 include_HEADERS = script/bitcoinconsensus.h
 libbitcoinconsensus_la_SOURCES = $(crypto_libbitcoin_crypto_base_a_SOURCES) $(libbitcoin_consensus_a_SOURCES)
 
 if GLIBC_BACK_COMPAT
   libbitcoinconsensus_la_SOURCES += compat/glibc_compat.cpp
 endif
 
 libbitcoinconsensus_la_LDFLAGS = $(AM_LDFLAGS) -no-undefined $(RELDFLAGS)
 libbitcoinconsensus_la_LIBADD = $(LIBSECP256K1)
 libbitcoinconsensus_la_CPPFLAGS = $(AM_CPPFLAGS) -I$(builddir)/obj -I$(srcdir)/secp256k1/include -DBUILD_BITCOIN_INTERNAL
 libbitcoinconsensus_la_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 
 endif
 #
 
 CTAES_DIST =  crypto/ctaes/bench.c
 CTAES_DIST += crypto/ctaes/ctaes.c
 CTAES_DIST += crypto/ctaes/ctaes.h
 CTAES_DIST += crypto/ctaes/README.md
 CTAES_DIST += crypto/ctaes/test.c
 
 CLEANFILES = $(EXTRA_LIBRARIES)
 
 CLEANFILES += *.gcda *.gcno
 CLEANFILES += compat/*.gcda compat/*.gcno
 CLEANFILES += consensus/*.gcda consensus/*.gcno
 CLEANFILES += crypto/*.gcda crypto/*.gcno
 CLEANFILES += policy/*.gcda policy/*.gcno
 CLEANFILES += primitives/*.gcda primitives/*.gcno
 CLEANFILES += script/*.gcda script/*.gcno
 CLEANFILES += support/*.gcda support/*.gcno
 CLEANFILES += univalue/*.gcda univalue/*.gcno
 CLEANFILES += wallet/*.gcda wallet/*.gcno
 CLEANFILES += wallet/test/*.gcda wallet/test/*.gcno
 CLEANFILES += zmq/*.gcda zmq/*.gcno
 CLEANFILES += obj/build.h
 
 EXTRA_DIST = $(CTAES_DIST)
 
 
 config/bitcoin-config.h: config/stamp-h1
 	@$(MAKE) -C $(top_builddir) $(subdir)/$(@)
 config/stamp-h1: $(top_srcdir)/$(subdir)/config/bitcoin-config.h.in $(top_builddir)/config.status
 	$(AM_V_at)$(MAKE) -C $(top_builddir) $(subdir)/$(@)
 $(top_srcdir)/$(subdir)/config/bitcoin-config.h.in:  $(am__configure_deps)
 	$(AM_V_at)$(MAKE) -C $(top_srcdir) $(subdir)/config/bitcoin-config.h.in
 
 clean-local:
 	-$(MAKE) -C secp256k1 clean
 	-$(MAKE) -C univalue clean
 	-rm -f leveldb/*/*.gcda leveldb/*/*.gcno leveldb/helpers/memenv/*.gcda leveldb/helpers/memenv/*.gcno
 	-rm -rf test/__pycache__
 
 .rc.o:
 	@test -f $(WINDRES)
 	## FIXME: How to get the appropriate modulename_CPPFLAGS in here?
 	$(AM_V_GEN) $(WINDRES) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(CPPFLAGS) -DWINDRES_PREPROC -i $< -o $@
 
 .mm.o:
 	$(AM_V_CXX) $(OBJCXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) \
 	  $(CPPFLAGS) $(AM_CXXFLAGS) $(QT_INCLUDES) $(AM_CXXFLAGS) $(PIE_FLAGS) $(CXXFLAGS) -c -o $@ $<
 
 check-symbols: $(bin_PROGRAMS)
 if GLIBC_BACK_COMPAT
 	@echo "Checking glibc back compat..."
 	$(AM_V_at) READELF=$(READELF) CPPFILT=$(CPPFILT) $(PYTHON) $(top_srcdir)/contrib/devtools/symbol-check.py < $(bin_PROGRAMS)
 endif
 
 check-security: $(bin_PROGRAMS)
 if HARDEN
 	@echo "Checking binary security..."
 	$(AM_V_at) READELF=$(READELF) OBJDUMP=$(OBJDUMP) $(PYTHON) $(top_srcdir)/contrib/devtools/security-check.py < $(bin_PROGRAMS)
 endif
 
 if ENABLE_BIP70
 %.pb.cc %.pb.h: %.proto
 	@test -f $(PROTOC)
 	$(AM_V_GEN) $(PROTOC) --cpp_out=$(@D) --proto_path=$(<D) $<
 endif
 
 if EMBEDDED_LEVELDB
 include Makefile.leveldb.include
 endif
 
 if ENABLE_TESTS
 include Makefile.test.include
 endif
 
 if ENABLE_BENCH
 include Makefile.bench.include
 endif
 
 if ENABLE_QT
 include Makefile.qt.include
 endif
 
 if ENABLE_QT_TESTS
 include Makefile.qttest.include
 endif
 
 if ENABLE_SEEDER_TESTS
 include Makefile.seedertest.include
 endif
diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 6d2df8df01..50ca147200 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -1,45 +1,191 @@
 // Copyright (c) 2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <interfaces/chain.h>
 
+#include <chain.h>
+#include <chainparams.h>
+#include <primitives/block.h>
+#include <primitives/blockhash.h>
 #include <sync.h>
 #include <util/system.h>
 #include <validation.h>
 
 #include <memory>
 #include <utility>
 
 namespace interfaces {
 namespace {
 
-    class LockImpl : public Chain::Lock {};
+    class LockImpl : public Chain::Lock {
+        Optional<int> getHeight() override {
+            int height = ::ChainActive().Height();
+            if (height >= 0) {
+                return height;
+            }
+            return nullopt;
+        }
+        Optional<int> getBlockHeight(const BlockHash &hash) override {
+            CBlockIndex *block = LookupBlockIndex(hash);
+            if (block && ::ChainActive().Contains(block)) {
+                return block->nHeight;
+            }
+            return nullopt;
+        }
+        int getBlockDepth(const BlockHash &hash) override {
+            const Optional<int> tip_height = getHeight();
+            const Optional<int> height = getBlockHeight(hash);
+            return tip_height && height ? *tip_height - *height + 1 : 0;
+        }
+        BlockHash getBlockHash(int height) override {
+            CBlockIndex *block = ::ChainActive()[height];
+            assert(block != nullptr);
+            return block->GetBlockHash();
+        }
+        int64_t getBlockTime(int height) override {
+            CBlockIndex *block = ::ChainActive()[height];
+            assert(block != nullptr);
+            return block->GetBlockTime();
+        }
+        int64_t getBlockMedianTimePast(int height) override {
+            CBlockIndex *block = ::ChainActive()[height];
+            assert(block != nullptr);
+            return block->GetMedianTimePast();
+        }
+        bool haveBlockOnDisk(int height) override {
+            CBlockIndex *block = ::ChainActive()[height];
+            return block && (block->nStatus.hasData() != 0) && block->nTx > 0;
+        }
+        Optional<int> findFirstBlockWithTime(int64_t time,
+                                             BlockHash *hash) override {
+            CBlockIndex *block = ::ChainActive().FindEarliestAtLeast(time);
+            if (block) {
+                if (hash) {
+                    *hash = block->GetBlockHash();
+                }
+                return block->nHeight;
+            }
+            return nullopt;
+        }
+        Optional<int> findFirstBlockWithTimeAndHeight(int64_t time,
+                                                      int height) override {
+            // TODO: Could update CChain::FindEarliestAtLeast() to take a height
+            // parameter and use it with std::lower_bound() to make this
+            // implementation more efficient and allow combining
+            // findFirstBlockWithTime and findFirstBlockWithTimeAndHeight into
+            // one method.
+            for (CBlockIndex *block = ::ChainActive()[height]; block;
+                 block = ::ChainActive().Next(block)) {
+                if (block->GetBlockTime() >= time) {
+                    return block->nHeight;
+                }
+            }
+            return nullopt;
+        }
+        Optional<int> findPruned(int start_height,
+                                 Optional<int> stop_height) override {
+            if (::fPruneMode) {
+                CBlockIndex *block = stop_height ? ::ChainActive()[*stop_height]
+                                                 : ::ChainActive().Tip();
+                while (block && block->nHeight >= start_height) {
+                    if (block->nStatus.hasData() == 0) {
+                        return block->nHeight;
+                    }
+                    block = block->pprev;
+                }
+            }
+            return nullopt;
+        }
+        Optional<int> findFork(const BlockHash &hash,
+                               Optional<int> *height) override {
+            const CBlockIndex *block = LookupBlockIndex(hash);
+            const CBlockIndex *fork =
+                block ? ::ChainActive().FindFork(block) : nullptr;
+            if (height) {
+                if (block) {
+                    *height = block->nHeight;
+                } else {
+                    height->reset();
+                }
+            }
+            if (fork) {
+                return fork->nHeight;
+            }
+            return nullopt;
+        }
+        bool isPotentialTip(const BlockHash &hash) override {
+            if (::ChainActive().Tip()->GetBlockHash() == hash) {
+                return true;
+            }
+            CBlockIndex *block = LookupBlockIndex(hash);
+            return block && block->GetAncestor(::ChainActive().Height()) ==
+                                ::ChainActive().Tip();
+        }
+        CBlockLocator getLocator() override {
+            return ::ChainActive().GetLocator();
+        }
+        Optional<int> findLocatorFork(const CBlockLocator &locator) override {
+            LockAnnotation lock(::cs_main);
+            if (CBlockIndex *fork =
+                    FindForkInGlobalIndex(::ChainActive(), locator)) {
+                return fork->nHeight;
+            }
+            return nullopt;
+        }
+    };
 
     class LockingStateImpl : public LockImpl,
                              public UniqueLock<CCriticalSection> {
         using UniqueLock::UniqueLock;
     };
 
     class ChainImpl : public Chain {
     public:
         std::unique_ptr<Chain::Lock> lock(bool try_lock) override {
             auto result = std::make_unique<LockingStateImpl>(
                 ::cs_main, "cs_main", __FILE__, __LINE__, try_lock);
             if (try_lock && result && !*result) {
                 return {};
             }
             return result;
         }
         std::unique_ptr<Chain::Lock> assumeLocked() override {
             return std::make_unique<LockImpl>();
         }
+        bool findBlock(const BlockHash &hash, CBlock *block, int64_t *time,
+                       int64_t *time_max) override {
+            CBlockIndex *index;
+            {
+                LOCK(cs_main);
+                index = LookupBlockIndex(hash);
+                if (!index) {
+                    return false;
+                }
+                if (time) {
+                    *time = index->GetBlockTime();
+                }
+                if (time_max) {
+                    *time_max = index->GetBlockTimeMax();
+                }
+            }
+            if (block &&
+                !ReadBlockFromDisk(*block, index, Params().GetConsensus())) {
+                block->SetNull();
+            }
+            return true;
+        }
+        double guessVerificationProgress(const BlockHash &block_hash) override {
+            LOCK(cs_main);
+            return GuessVerificationProgress(Params().TxData(),
+                                             LookupBlockIndex(block_hash));
+        }
     };
 
 } // namespace
 
 std::unique_ptr<Chain> MakeChain() {
     return std::make_unique<ChainImpl>();
 }
 
 } // namespace interfaces
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index bd7b734722..550a221abd 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -1,83 +1,176 @@
 // Copyright (c) 2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_INTERFACES_CHAIN_H
 #define BITCOIN_INTERFACES_CHAIN_H
 
+#include <optional.h>
+
+#include <cstdint>
 #include <memory>
 #include <string>
 #include <vector>
 
+struct BlockHash;
+class CBlock;
+struct CBlockLocator;
 class CChainParams;
 class CScheduler;
 
 namespace interfaces {
 
 //! Interface for giving wallet processes access to blockchain state.
 class Chain {
 public:
     virtual ~Chain() {}
 
     //! Interface for querying locked chain state, used by legacy code that
     //! assumes state won't change between calls. New code should avoid using
     //! the Lock interface and instead call higher-level Chain methods
     //! that return more information so the chain doesn't need to stay locked
     //! between calls.
     class Lock {
     public:
         virtual ~Lock() {}
+
+        //! Get current chain height, not including genesis block (returns 0 if
+        //! chain only contains genesis block, nullopt if chain does not contain
+        //! any blocks).
+        virtual Optional<int> getHeight() = 0;
+
+        //! Get block height above genesis block. Returns 0 for genesis block,
+        //! 1 for following block, and so on. Returns nullopt for a block not
+        //! included in the current chain.
+        virtual Optional<int> getBlockHeight(const BlockHash &hash) = 0;
+
+        //! Get block depth. Returns 1 for chain tip, 2 for preceding block, and
+        //! so on. Returns 0 for a block not included in the current chain.
+        virtual int getBlockDepth(const BlockHash &hash) = 0;
+
+        //! Get block hash. Height must be valid or this function will abort.
+        virtual BlockHash getBlockHash(int height) = 0;
+
+        //! Get block time. Height must be valid or this function will abort.
+        virtual int64_t getBlockTime(int height) = 0;
+
+        //! Get block median time past. Height must be valid or this function
+        //! will abort.
+        virtual int64_t getBlockMedianTimePast(int height) = 0;
+
+        //! Check that the block is available on disk (i.e. has not been
+        //! pruned), and contains transactions.
+        virtual bool haveBlockOnDisk(int height) = 0;
+
+        //! Return height of the first block in the chain with timestamp equal
+        //! or greater than the given time, or nullopt if there is no block with
+        //! a high enough timestamp. Also return the block hash as an optional
+        //! output parameter (to avoid the cost of a second lookup in case this
+        //! information is needed.)
+        virtual Optional<int> findFirstBlockWithTime(int64_t time,
+                                                     BlockHash *hash) = 0;
+
+        //! Return height of the first block in the chain with timestamp equal
+        //! or greater than the given time and height equal or greater than the
+        //! given height, or nullopt if there is no such block.
+        //!
+        //! Calling this with height 0 is equivalent to calling
+        //! findFirstBlockWithTime, but less efficient because it requires a
+        //! linear instead of a binary search.
+        virtual Optional<int> findFirstBlockWithTimeAndHeight(int64_t time,
+                                                              int height) = 0;
+
+        //! Return height of last block in the specified range which is pruned,
+        //! or nullopt if no block in the range is pruned. Range is inclusive.
+        virtual Optional<int>
+        findPruned(int start_height = 0,
+                   Optional<int> stop_height = nullopt) = 0;
+
+        //! Return height of the highest block on the chain that is an ancestor
+        //! of the specified block, or nullopt if no common ancestor is found.
+        //! Also return the height of the specified block as an optional output
+        //! parameter (to avoid the cost of a second hash lookup in case this
+        //! information is desired).
+        virtual Optional<int> findFork(const BlockHash &hash,
+                                       Optional<int> *height) = 0;
+
+        //! Return true if block hash points to the current chain tip, or to a
+        //! possible descendant of the current chain tip that isn't currently
+        //! connected.
+        virtual bool isPotentialTip(const BlockHash &hash) = 0;
+
+        //! Get locator for the current chain tip.
+        virtual CBlockLocator getLocator() = 0;
+
+        //! Return height of the latest block common to locator and chain, which
+        //! is guaranteed to be an ancestor of the block used to create the
+        //! locator.
+        virtual Optional<int> findLocatorFork(const CBlockLocator &locator) = 0;
     };
 
     //! Return Lock interface. Chain is locked when this is called, and
     //! unlocked when the returned interface is freed.
     virtual std::unique_ptr<Lock> lock(bool try_lock = false) = 0;
 
     //! Return Lock interface assuming chain is already locked. This
     //! method is temporary and is only used in a few places to avoid changing
     //! behavior while code is transitioned to use the Chain::Lock interface.
     virtual std::unique_ptr<Lock> assumeLocked() = 0;
+
+    //! Return whether node has the block and optionally return block metadata
+    //! or contents.
+    //!
+    //! If a block pointer is provided to retrieve the block contents, and the
+    //! block exists but doesn't have data (for example due to pruning), the
+    //! block will be empty and all fields set to null.
+    virtual bool findBlock(const BlockHash &hash, CBlock *block = nullptr,
+                           int64_t *time = nullptr,
+                           int64_t *max_time = nullptr) = 0;
+
+    //! Estimate fraction of total transactions verified if blocks up to
+    //! the specified block hash are verified.
+    virtual double guessVerificationProgress(const BlockHash &block_hash) = 0;
 };
 
 //! Interface to let node manage chain clients (wallets, or maybe tools for
 //! monitoring and analysis in the future).
 class ChainClient {
 public:
     virtual ~ChainClient() {}
 
     //! Register rpcs.
     virtual void registerRpcs() = 0;
 
     //! Check for errors before loading.
     virtual bool verify(const CChainParams &chainParams) = 0;
 
     //! Load saved state.
     virtual bool load(const CChainParams &chainParams) = 0;
 
     //! Start client execution and provide a scheduler.
     virtual void start(CScheduler &scheduler) = 0;
 
     //! Save state to disk.
     virtual void flush() = 0;
 
     //! Shut down client.
     virtual void stop() = 0;
 };
 
 //! Return implementation of Chain interface.
 std::unique_ptr<Chain> MakeChain();
 
 //! Return implementation of ChainClient interface for a wallet client. This
 //! function will be undefined in builds where ENABLE_WALLET is false.
 //!
 //! Currently, wallets are the only chain clients. But in the future, other
 //! types of chain clients could be added, such as tools for monitoring,
 //! analysis, or fee estimation. These clients need to expose their own
 //! MakeXXXClient functions returning their implementations of the ChainClient
 //! interface.
 std::unique_ptr<ChainClient>
 MakeWalletClient(Chain &chain, std::vector<std::string> wallet_filenames);
 
 } // namespace interfaces
 
 #endif // BITCOIN_INTERFACES_CHAIN_H
diff --git a/src/interfaces/wallet.cpp b/src/interfaces/wallet.cpp
index 62f482ddf8..860145e297 100644
--- a/src/interfaces/wallet.cpp
+++ b/src/interfaces/wallet.cpp
@@ -1,527 +1,532 @@
 // Copyright (c) 2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <interfaces/wallet.h>
 
 #include <amount.h>
 #include <chain.h>
 #include <consensus/validation.h>
 #include <init.h>
 #include <interfaces/chain.h>
 #include <interfaces/handler.h>
 #include <net.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <primitives/transaction.h>
 #include <rpc/server.h>
 #include <scheduler.h>
 #include <script/ismine.h>
 #include <script/standard.h>
 #include <support/allocators/secure.h>
 #include <sync.h>
 #include <timedata.h>
 #include <ui_interface.h>
 #include <util/system.h>
 #include <validation.h>
 #include <wallet/fees.h>
 #include <wallet/finaltx.h>
 #include <wallet/rpcdump.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/wallet.h>
 #include <wallet/walletutil.h>
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 namespace interfaces {
 namespace {
 
     class PendingWalletTxImpl : public PendingWalletTx {
     public:
         PendingWalletTxImpl(CWallet &wallet)
             : m_wallet(wallet), m_key(&wallet) {}
 
         const CTransaction &get() override { return *m_tx; }
 
         bool commit(WalletValueMap value_map, WalletOrderForm order_form,
                     std::string &reject_reason) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             CValidationState state;
             if (!m_wallet.CommitTransaction(m_tx, std::move(value_map),
                                             std::move(order_form), m_key,
                                             g_connman.get(), state)) {
                 reject_reason = state.GetRejectReason();
                 return false;
             }
             return true;
         }
 
         CTransactionRef m_tx;
         CWallet &m_wallet;
         CReserveKey m_key;
     };
 
     //! Construct wallet tx struct.
     static WalletTx MakeWalletTx(interfaces::Chain::Lock &locked_chain,
                                  CWallet &wallet, const CWalletTx &wtx) {
         WalletTx result;
         result.tx = wtx.tx;
         result.txin_is_mine.reserve(wtx.tx->vin.size());
         for (const auto &txin : wtx.tx->vin) {
             result.txin_is_mine.emplace_back(wallet.IsMine(txin));
         }
         result.txout_is_mine.reserve(wtx.tx->vout.size());
         result.txout_address.reserve(wtx.tx->vout.size());
         result.txout_address_is_mine.reserve(wtx.tx->vout.size());
         for (const auto &txout : wtx.tx->vout) {
             result.txout_is_mine.emplace_back(wallet.IsMine(txout));
             result.txout_address.emplace_back();
             result.txout_address_is_mine.emplace_back(
                 ExtractDestination(txout.scriptPubKey,
                                    result.txout_address.back())
                     ? IsMine(wallet, result.txout_address.back())
                     : ISMINE_NO);
         }
         result.credit = wtx.GetCredit(locked_chain, ISMINE_ALL);
         result.debit = wtx.GetDebit(ISMINE_ALL);
         result.change = wtx.GetChange();
         result.time = wtx.GetTxTime();
         result.value_map = wtx.mapValue;
         result.is_coinbase = wtx.IsCoinBase();
         return result;
     }
 
     //! Construct wallet tx status struct.
     static WalletTxStatus
     MakeWalletTxStatus(interfaces::Chain::Lock &locked_chain,
                        const CWalletTx &wtx) {
         // Temporary, for CheckFinalTx below. Removed in upcoming commit.
         LockAnnotation lock(::cs_main);
 
         WalletTxStatus result;
         CBlockIndex *block = LookupBlockIndex(wtx.hashBlock);
         result.block_height =
             (block ? block->nHeight : std::numeric_limits<int>::max());
         result.blocks_to_maturity = wtx.GetBlocksToMaturity(locked_chain);
         result.depth_in_main_chain = wtx.GetDepthInMainChain(locked_chain);
         result.time_received = wtx.nTimeReceived;
         result.lock_time = wtx.tx->nLockTime;
         result.is_final = CheckFinalTx(*wtx.tx);
         result.is_trusted = wtx.IsTrusted(locked_chain);
         result.is_abandoned = wtx.isAbandoned();
         result.is_coinbase = wtx.IsCoinBase();
         result.is_in_main_chain = wtx.IsInMainChain(locked_chain);
         return result;
     }
 
     //! Construct wallet TxOut struct.
     static WalletTxOut MakeWalletTxOut(interfaces::Chain::Lock &locked_chain,
                                        CWallet &wallet, const CWalletTx &wtx,
                                        int n, int depth)
         EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet) {
         WalletTxOut result;
         result.txout = wtx.tx->vout[n];
         result.time = wtx.GetTxTime();
         result.depth_in_main_chain = depth;
         result.is_spent =
             wallet.IsSpent(locked_chain, COutPoint(wtx.GetId(), n));
         return result;
     }
 
     class WalletImpl : public Wallet {
     public:
         WalletImpl(const std::shared_ptr<CWallet> &wallet)
             : m_shared_wallet(wallet), m_wallet(*wallet.get()) {}
 
         bool encryptWallet(const SecureString &wallet_passphrase) override {
             return m_wallet.EncryptWallet(wallet_passphrase);
         }
         bool isCrypted() override { return m_wallet.IsCrypted(); }
         bool lock() override { return m_wallet.Lock(); }
         bool unlock(const SecureString &wallet_passphrase) override {
             return m_wallet.Unlock(wallet_passphrase);
         }
         bool isLocked() override { return m_wallet.IsLocked(); }
         bool changeWalletPassphrase(
             const SecureString &old_wallet_passphrase,
             const SecureString &new_wallet_passphrase) override {
             return m_wallet.ChangeWalletPassphrase(old_wallet_passphrase,
                                                    new_wallet_passphrase);
         }
         void abortRescan() override { m_wallet.AbortRescan(); }
         bool backupWallet(const std::string &filename) override {
             return m_wallet.BackupWallet(filename);
         }
         std::string getWalletName() override { return m_wallet.GetName(); }
         std::set<CTxDestination>
         getLabelAddresses(const std::string &label) override {
             return m_wallet.GetLabelAddresses(label);
         };
         bool getKeyFromPool(bool internal, CPubKey &pub_key) override {
             return m_wallet.GetKeyFromPool(pub_key, internal);
         }
         const CChainParams &getChainParams() override {
             return m_wallet.chainParams;
         }
         bool getPubKey(const CKeyID &address, CPubKey &pub_key) override {
             return m_wallet.GetPubKey(address, pub_key);
         }
         bool getPrivKey(const CKeyID &address, CKey &key) override {
             return m_wallet.GetKey(address, key);
         }
         bool isSpendable(const CTxDestination &dest) override {
             return IsMine(m_wallet, dest) & ISMINE_SPENDABLE;
         }
         bool haveWatchOnly() override { return m_wallet.HaveWatchOnly(); };
         bool setAddressBook(const CTxDestination &dest, const std::string &name,
                             const std::string &purpose) override {
             return m_wallet.SetAddressBook(dest, name, purpose);
         }
         bool delAddressBook(const CTxDestination &dest) override {
             return m_wallet.DelAddressBook(dest);
         }
         bool getAddress(const CTxDestination &dest, std::string *name,
                         isminetype *is_mine, std::string *purpose) override {
             LOCK(m_wallet.cs_wallet);
             auto it = m_wallet.mapAddressBook.find(dest);
             if (it == m_wallet.mapAddressBook.end()) {
                 return false;
             }
             if (name) {
                 *name = it->second.name;
             }
             if (is_mine) {
                 *is_mine = IsMine(m_wallet, dest);
             }
             if (purpose) {
                 *purpose = it->second.purpose;
             }
             return true;
         }
         std::vector<WalletAddress> getAddresses() override {
             LOCK(m_wallet.cs_wallet);
             std::vector<WalletAddress> result;
             for (const auto &item : m_wallet.mapAddressBook) {
                 result.emplace_back(item.first, IsMine(m_wallet, item.first),
                                     item.second.name, item.second.purpose);
             }
             return result;
         }
         void learnRelatedScripts(const CPubKey &key, OutputType type) override {
             m_wallet.LearnRelatedScripts(key, type);
         }
         bool addDestData(const CTxDestination &dest, const std::string &key,
                          const std::string &value) override {
             LOCK(m_wallet.cs_wallet);
             return m_wallet.AddDestData(dest, key, value);
         }
         bool eraseDestData(const CTxDestination &dest,
                            const std::string &key) override {
             LOCK(m_wallet.cs_wallet);
             return m_wallet.EraseDestData(dest, key);
         }
         std::vector<std::string>
         getDestValues(const std::string &prefix) override {
             return m_wallet.GetDestValues(prefix);
         }
         void lockCoin(const COutPoint &output) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             return m_wallet.LockCoin(output);
         }
         void unlockCoin(const COutPoint &output) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             return m_wallet.UnlockCoin(output);
         }
         bool isLockedCoin(const COutPoint &output) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             return m_wallet.IsLockedCoin(output);
         }
         void listLockedCoins(std::vector<COutPoint> &outputs) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             return m_wallet.ListLockedCoins(outputs);
         }
         std::unique_ptr<PendingWalletTx>
         createTransaction(const std::vector<CRecipient> &recipients,
                           const CCoinControl &coin_control, bool sign,
                           int &change_pos, Amount &fee,
                           std::string &fail_reason) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             auto pending = std::make_unique<PendingWalletTxImpl>(m_wallet);
             if (!m_wallet.CreateTransaction(
                     *locked_chain, recipients, pending->m_tx, pending->m_key,
                     fee, change_pos, fail_reason, coin_control, sign)) {
                 return {};
             }
             return pending;
         }
         bool transactionCanBeAbandoned(const TxId &txid) override {
             return m_wallet.TransactionCanBeAbandoned(txid);
         }
         bool abandonTransaction(const TxId &txid) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             return m_wallet.AbandonTransaction(*locked_chain, txid);
         }
         CTransactionRef getTx(const TxId &txid) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             auto mi = m_wallet.mapWallet.find(txid);
             if (mi != m_wallet.mapWallet.end()) {
                 return mi->second.tx;
             }
             return {};
         }
         WalletTx getWalletTx(const TxId &txid) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             auto mi = m_wallet.mapWallet.find(txid);
             if (mi != m_wallet.mapWallet.end()) {
                 return MakeWalletTx(*locked_chain, m_wallet, mi->second);
             }
             return {};
         }
         std::vector<WalletTx> getWalletTxs() override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             std::vector<WalletTx> result;
             result.reserve(m_wallet.mapWallet.size());
             for (const auto &entry : m_wallet.mapWallet) {
                 result.emplace_back(
                     MakeWalletTx(*locked_chain, m_wallet, entry.second));
             }
             return result;
         }
         bool tryGetTxStatus(const TxId &txid,
                             interfaces::WalletTxStatus &tx_status,
                             int &num_blocks, int64_t &block_time) override {
             auto locked_chain = m_wallet.chain().lock(true /* try_lock */);
             if (!locked_chain) {
                 return false;
             }
             TRY_LOCK(m_wallet.cs_wallet, locked_wallet);
             if (!locked_wallet) {
                 return false;
             }
             auto mi = m_wallet.mapWallet.find(txid);
             if (mi == m_wallet.mapWallet.end()) {
                 return false;
             }
-            num_blocks = ::ChainActive().Height();
-            block_time = ::ChainActive().Tip()->GetBlockTime();
+            if (Optional<int> height = locked_chain->getHeight()) {
+                num_blocks = *height;
+                block_time = locked_chain->getBlockTime(*height);
+            } else {
+                num_blocks = -1;
+                block_time = -1;
+            }
             tx_status = MakeWalletTxStatus(*locked_chain, mi->second);
             return true;
         }
         WalletTx getWalletTxDetails(const TxId &txid, WalletTxStatus &tx_status,
                                     WalletOrderForm &order_form,
                                     bool &in_mempool,
                                     int &num_blocks) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             auto mi = m_wallet.mapWallet.find(txid);
             if (mi != m_wallet.mapWallet.end()) {
-                num_blocks = ::ChainActive().Height();
+                num_blocks = locked_chain->getHeight().value_or(-1);
                 in_mempool = mi->second.InMempool();
                 order_form = mi->second.vOrderForm;
                 tx_status = MakeWalletTxStatus(*locked_chain, mi->second);
                 return MakeWalletTx(*locked_chain, m_wallet, mi->second);
             }
             return {};
         }
         WalletBalances getBalances() override {
             WalletBalances result;
             result.balance = m_wallet.GetBalance();
             result.unconfirmed_balance = m_wallet.GetUnconfirmedBalance();
             result.immature_balance = m_wallet.GetImmatureBalance();
             result.have_watch_only = m_wallet.HaveWatchOnly();
             if (result.have_watch_only) {
                 result.watch_only_balance =
                     m_wallet.GetBalance(ISMINE_WATCH_ONLY);
                 result.unconfirmed_watch_only_balance =
                     m_wallet.GetUnconfirmedWatchOnlyBalance();
                 result.immature_watch_only_balance =
                     m_wallet.GetImmatureWatchOnlyBalance();
             }
             return result;
         }
         bool tryGetBalances(WalletBalances &balances,
                             int &num_blocks) override {
             auto locked_chain = m_wallet.chain().lock(true /* try_lock */);
             if (!locked_chain) {
                 return false;
             }
             TRY_LOCK(m_wallet.cs_wallet, locked_wallet);
             if (!locked_wallet) {
                 return false;
             }
             balances = getBalances();
-            num_blocks = ::ChainActive().Height();
+            num_blocks = locked_chain->getHeight().value_or(-1);
             return true;
         }
         Amount getBalance() override { return m_wallet.GetBalance(); }
         Amount getAvailableBalance(const CCoinControl &coin_control) override {
             return m_wallet.GetAvailableBalance(&coin_control);
         }
         isminetype txinIsMine(const CTxIn &txin) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             return m_wallet.IsMine(txin);
         }
         isminetype txoutIsMine(const CTxOut &txout) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             return m_wallet.IsMine(txout);
         }
         Amount getDebit(const CTxIn &txin, isminefilter filter) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             return m_wallet.GetDebit(txin, filter);
         }
         Amount getCredit(const CTxOut &txout, isminefilter filter) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             return m_wallet.GetCredit(txout, filter);
         }
         CoinsList listCoins() override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             CoinsList result;
             for (const auto &entry : m_wallet.ListCoins(*locked_chain)) {
                 auto &group = result[entry.first];
                 for (const auto &coin : entry.second) {
                     group.emplace_back(COutPoint(coin.tx->GetId(), coin.i),
                                        MakeWalletTxOut(*locked_chain, m_wallet,
                                                        *coin.tx, coin.i,
                                                        coin.nDepth));
                 }
             }
             return result;
         }
         std::vector<WalletTxOut>
         getCoins(const std::vector<COutPoint> &outputs) override {
             auto locked_chain = m_wallet.chain().lock();
             LOCK(m_wallet.cs_wallet);
             std::vector<WalletTxOut> result;
             result.reserve(outputs.size());
             for (const auto &output : outputs) {
                 result.emplace_back();
                 auto it = m_wallet.mapWallet.find(output.GetTxId());
                 if (it != m_wallet.mapWallet.end()) {
                     int depth = it->second.GetDepthInMainChain(*locked_chain);
                     if (depth >= 0) {
                         result.back() =
                             MakeWalletTxOut(*locked_chain, m_wallet, it->second,
                                             output.GetN(), depth);
                     }
                 }
             }
             return result;
         }
         bool hdEnabled() override { return m_wallet.IsHDEnabled(); }
         OutputType getDefaultAddressType() override {
             return m_wallet.m_default_address_type;
         }
         bool canGetAddresses() override { return m_wallet.CanGetAddresses(); }
         bool IsWalletFlagSet(uint64_t flag) override {
             return m_wallet.IsWalletFlagSet(flag);
         }
         OutputType getDefaultChangeType() override {
             return m_wallet.m_default_change_type;
         }
         std::unique_ptr<Handler> handleUnload(UnloadFn fn) override {
             return MakeHandler(m_wallet.NotifyUnload.connect(fn));
         }
         std::unique_ptr<Handler>
         handleShowProgress(ShowProgressFn fn) override {
             return MakeHandler(m_wallet.ShowProgress.connect(fn));
         }
         std::unique_ptr<Handler>
         handleStatusChanged(StatusChangedFn fn) override {
             return MakeHandler(m_wallet.NotifyStatusChanged.connect(
                 [fn](CCryptoKeyStore *) { fn(); }));
         }
         std::unique_ptr<Handler>
         handleAddressBookChanged(AddressBookChangedFn fn) override {
             return MakeHandler(m_wallet.NotifyAddressBookChanged.connect(
                 [fn](CWallet *, const CTxDestination &address,
                      const std::string &label, bool is_mine,
                      const std::string &purpose, ChangeType status) {
                     fn(address, label, is_mine, purpose, status);
                 }));
         }
         std::unique_ptr<Handler>
         handleTransactionChanged(TransactionChangedFn fn) override {
             return MakeHandler(m_wallet.NotifyTransactionChanged.connect(
                 [fn](CWallet *, const TxId &txid, ChangeType status) {
                     fn(txid, status);
                 }));
         }
         std::unique_ptr<Handler>
         handleWatchOnlyChanged(WatchOnlyChangedFn fn) override {
             return MakeHandler(m_wallet.NotifyWatchonlyChanged.connect(fn));
         }
         std::unique_ptr<Handler>
         handleCanGetAddressesChanged(CanGetAddressesChangedFn fn) override {
             return MakeHandler(
                 m_wallet.NotifyCanGetAddressesChanged.connect(fn));
         }
         Amount getRequiredFee(unsigned int tx_bytes) override {
             return GetRequiredFee(m_wallet, tx_bytes);
         }
         Amount getMinimumFee(unsigned int tx_bytes,
                              const CCoinControl &coin_control) override {
             return GetMinimumFee(m_wallet, tx_bytes, coin_control, g_mempool);
         }
 
         std::shared_ptr<CWallet> m_shared_wallet;
         CWallet &m_wallet;
     };
 
     class WalletClientImpl : public ChainClient {
     public:
         WalletClientImpl(Chain &chain,
                          std::vector<std::string> wallet_filenames)
             : m_chain(chain), m_wallet_filenames(std::move(wallet_filenames)) {}
 
         void registerRpcs() override {
             RegisterWalletRPCCommands(::tableRPC);
             RegisterDumpRPCCommands(::tableRPC);
         }
         bool verify(const CChainParams &chainParams) override {
             return VerifyWallets(chainParams, m_chain, m_wallet_filenames);
         }
         bool load(const CChainParams &chainParams) override {
             return LoadWallets(chainParams, m_chain, m_wallet_filenames);
         }
         void start(CScheduler &scheduler) override {
             return StartWallets(scheduler);
         }
         void flush() override { return FlushWallets(); }
         void stop() override { return StopWallets(); }
         ~WalletClientImpl() override { UnloadWallets(); }
 
         Chain &m_chain;
         std::vector<std::string> m_wallet_filenames;
     };
 
 } // namespace
 
 std::unique_ptr<Wallet> MakeWallet(const std::shared_ptr<CWallet> &wallet) {
     return std::make_unique<WalletImpl>(wallet);
 }
 
 std::unique_ptr<ChainClient>
 MakeWalletClient(Chain &chain, std::vector<std::string> wallet_filenames) {
     return std::make_unique<WalletClientImpl>(chain,
                                               std::move(wallet_filenames));
 }
 
 } // namespace interfaces
diff --git a/src/optional.h b/src/optional.h
new file mode 100644
index 0000000000..16c9eeeeb9
--- /dev/null
+++ b/src/optional.h
@@ -0,0 +1,16 @@
+// Copyright (c) 2017 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_OPTIONAL_H
+#define BITCOIN_OPTIONAL_H
+
+#include <boost/optional.hpp>
+
+//! Substitute for C++17 std::optional
+template <typename T> using Optional = boost::optional<T>;
+
+//! Substitute for C++17 std::nullopt
+static auto &nullopt = boost::none;
+
+#endif // BITCOIN_OPTIONAL_H
diff --git a/src/qt/test/wallettests.cpp b/src/qt/test/wallettests.cpp
index 5d401f3b3b..9378ee7d7d 100644
--- a/src/qt/test/wallettests.cpp
+++ b/src/qt/test/wallettests.cpp
@@ -1,260 +1,258 @@
 #include <qt/test/util.h>
 #include <qt/test/wallettests.h>
 
 #include <base58.h>
 #include <cashaddrenc.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <interfaces/chain.h>
 #include <interfaces/node.h>
 #include <key_io.h>
 #include <qt/bitcoinamountfield.h>
 #include <qt/optionsmodel.h>
 #include <qt/overviewpage.h>
 #include <qt/platformstyle.h>
 #include <qt/qvalidatedlineedit.h>
 #include <qt/receivecoinsdialog.h>
 #include <qt/receiverequestdialog.h>
 #include <qt/recentrequeststablemodel.h>
 #include <qt/sendcoinsdialog.h>
 #include <qt/sendcoinsentry.h>
 #include <qt/transactiontablemodel.h>
 #include <qt/walletmodel.h>
 #include <validation.h>
 #include <wallet/wallet.h>
 
 #include <test/setup_common.h>
 
 #include <QAbstractButton>
 #include <QApplication>
 #include <QDialogButtonBox>
 #include <QListView>
 #include <QPushButton>
 #include <QTextEdit>
 #include <QTimer>
 #include <QVBoxLayout>
 
 #include <memory>
 
 namespace {
 //! Press "Yes" or "Cancel" buttons in modal send confirmation dialog.
 void ConfirmSend(QString *text = nullptr, bool cancel = false) {
     QTimer::singleShot(0, Qt::PreciseTimer, [text, cancel]() {
         for (QWidget *widget : QApplication::topLevelWidgets()) {
             if (widget->inherits("SendConfirmationDialog")) {
                 SendConfirmationDialog *dialog =
                     qobject_cast<SendConfirmationDialog *>(widget);
                 if (text) {
                     *text = dialog->text();
                 }
                 QAbstractButton *button = dialog->button(
                     cancel ? QMessageBox::Cancel : QMessageBox::Yes);
                 button->setEnabled(true);
                 button->click();
             }
         }
     });
 }
 
 //! Send coins to address and return txid.
 TxId SendCoins(CWallet &wallet, SendCoinsDialog &sendCoinsDialog,
                const CTxDestination &address, Amount amount) {
     QVBoxLayout *entries = sendCoinsDialog.findChild<QVBoxLayout *>("entries");
     SendCoinsEntry *entry =
         qobject_cast<SendCoinsEntry *>(entries->itemAt(0)->widget());
     entry->findChild<QValidatedLineEdit *>("payTo")->setText(
         QString::fromStdString(EncodeCashAddr(address, Params())));
     entry->findChild<BitcoinAmountField *>("payAmount")->setValue(amount);
     TxId txid;
     boost::signals2::scoped_connection c =
         wallet.NotifyTransactionChanged.connect(
             [&txid](CWallet *, const TxId &hash, ChangeType status) {
                 if (status == CT_NEW) {
                     txid = hash;
                 }
             });
     ConfirmSend();
     QMetaObject::invokeMethod(&sendCoinsDialog, "on_sendButton_clicked");
     return txid;
 }
 
 //! Find index of txid in transaction list.
 QModelIndex FindTx(const QAbstractItemModel &model, const uint256 &txid) {
     QString hash = QString::fromStdString(txid.ToString());
     int rows = model.rowCount({});
     for (int row = 0; row < rows; ++row) {
         QModelIndex index = model.index(row, 0, {});
         if (model.data(index, TransactionTableModel::TxHashRole) == hash) {
             return index;
         }
     }
     return {};
 }
 
 //! Simple qt wallet tests.
 //
 // Test widgets can be debugged interactively calling show() on them and
 // manually running the event loop, e.g.:
 //
 //     sendCoinsDialog.show();
 //     QEventLoop().exec();
 //
 // This also requires overriding the default minimal Qt platform:
 //
 //     src/qt/test/test_bitcoin-qt -platform xcb      # Linux
 //     src/qt/test/test_bitcoin-qt -platform windows  # Windows
 //     src/qt/test/test_bitcoin-qt -platform cocoa    # macOS
 void TestGUI() {
     // Set up wallet and chain with 105 blocks (5 mature blocks for spending).
     TestChain100Setup test;
     for (int i = 0; i < 5; ++i) {
         test.CreateAndProcessBlock(
             {}, GetScriptForRawPubKey(test.coinbaseKey.GetPubKey()));
     }
 
     auto chain = interfaces::MakeChain();
     std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
         Params(), *chain, WalletLocation(), WalletDatabase::CreateMock());
 
     bool firstRun;
     wallet->LoadWallet(firstRun);
     {
         LOCK(wallet->cs_wallet);
         wallet->SetAddressBook(
             GetDestinationForKey(test.coinbaseKey.GetPubKey(),
                                  wallet->m_default_address_type),
             "", "receive");
         wallet->AddKeyPubKey(test.coinbaseKey, test.coinbaseKey.GetPubKey());
     }
     {
         auto locked_chain = wallet->chain().lock();
         WalletRescanReserver reserver(wallet.get());
         reserver.reserve();
-        const CBlockIndex *const null_block = nullptr;
-        const CBlockIndex *stop_block, *failed_block;
-        QCOMPARE(wallet->ScanForWalletTransactions(
-                     ::ChainActive().Genesis(), nullptr, reserver, failed_block,
-                     stop_block, true /* fUpdate */),
-                 CWallet::ScanResult::SUCCESS);
-        QCOMPARE(stop_block, ::ChainActive().Tip());
-        QCOMPARE(failed_block, null_block);
+        CWallet::ScanResult result = wallet->ScanForWalletTransactions(
+            locked_chain->getBlockHash(0), BlockHash(), reserver,
+            true /* fUpdate */);
+        QCOMPARE(result.status, CWallet::ScanResult::SUCCESS);
+        QCOMPARE(result.stop_block, ::ChainActive().Tip()->GetBlockHash());
+        QVERIFY(result.failed_block.IsNull());
     }
     wallet->SetBroadcastTransactions(true);
 
     // Create widgets for sending coins and listing transactions.
     std::unique_ptr<const PlatformStyle> platformStyle(
         PlatformStyle::instantiate("other"));
     auto node = interfaces::MakeNode();
     OptionsModel optionsModel(*node);
     AddWallet(wallet);
     WalletModel walletModel(std::move(node->getWallets().back()), *node,
                             platformStyle.get(), &optionsModel);
     RemoveWallet(wallet);
 
     // Send two transactions, and verify they are added to transaction list.
     SendCoinsDialog sendCoinsDialog(platformStyle.get(), &walletModel);
     TransactionTableModel *transactionTableModel =
         walletModel.getTransactionTableModel();
     QCOMPARE(transactionTableModel->rowCount({}), 105);
     TxId txid1 = SendCoins(*wallet.get(), sendCoinsDialog,
                            CTxDestination(CKeyID()), 5 * COIN);
     TxId txid2 = SendCoins(*wallet.get(), sendCoinsDialog,
                            CTxDestination(CKeyID()), 10 * COIN);
     QCOMPARE(transactionTableModel->rowCount({}), 107);
     QVERIFY(FindTx(*transactionTableModel, txid1).isValid());
     QVERIFY(FindTx(*transactionTableModel, txid2).isValid());
 
     // Check current balance on OverviewPage
     OverviewPage overviewPage(platformStyle.get());
     overviewPage.setWalletModel(&walletModel);
     QLabel *balanceLabel = overviewPage.findChild<QLabel *>("labelBalance");
     QString balanceText = balanceLabel->text();
     int unit = walletModel.getOptionsModel()->getDisplayUnit();
     Amount balance = walletModel.wallet().getBalance();
     QString balanceComparison = BitcoinUnits::formatWithUnit(
         unit, balance, false, BitcoinUnits::separatorAlways);
     QCOMPARE(balanceText, balanceComparison);
 
     // Check Request Payment button
     ReceiveCoinsDialog receiveCoinsDialog(platformStyle.get());
     receiveCoinsDialog.setModel(&walletModel);
     RecentRequestsTableModel *requestTableModel =
         walletModel.getRecentRequestsTableModel();
 
     // Label input
     QLineEdit *labelInput =
         receiveCoinsDialog.findChild<QLineEdit *>("reqLabel");
     labelInput->setText("TEST_LABEL_1");
 
     // Amount input
     BitcoinAmountField *amountInput =
         receiveCoinsDialog.findChild<BitcoinAmountField *>("reqAmount");
     amountInput->setValue(1 * SATOSHI);
 
     // Message input
     QLineEdit *messageInput =
         receiveCoinsDialog.findChild<QLineEdit *>("reqMessage");
     messageInput->setText("TEST_MESSAGE_1");
     int initialRowCount = requestTableModel->rowCount({});
     QPushButton *requestPaymentButton =
         receiveCoinsDialog.findChild<QPushButton *>("receiveButton");
     requestPaymentButton->click();
     for (QWidget *widget : QApplication::topLevelWidgets()) {
         if (widget->inherits("ReceiveRequestDialog")) {
             ReceiveRequestDialog *receiveRequestDialog =
                 qobject_cast<ReceiveRequestDialog *>(widget);
             QTextEdit *rlist =
                 receiveRequestDialog->QObject::findChild<QTextEdit *>("outUri");
             QString paymentText = rlist->toPlainText();
             QStringList paymentTextList = paymentText.split('\n');
             QCOMPARE(paymentTextList.at(0), QString("Payment information"));
             QVERIFY(paymentTextList.at(1).indexOf(QString("URI: bchreg:")) !=
                     -1);
             QVERIFY(paymentTextList.at(2).indexOf(QString("Address:")) != -1);
             QCOMPARE(paymentTextList.at(3),
                      QString("Amount: 0.00000001 ") +
                          QString::fromStdString(CURRENCY_UNIT));
             QCOMPARE(paymentTextList.at(4), QString("Label: TEST_LABEL_1"));
             QCOMPARE(paymentTextList.at(5), QString("Message: TEST_MESSAGE_1"));
         }
     }
 
     // Clear button
     QPushButton *clearButton =
         receiveCoinsDialog.findChild<QPushButton *>("clearButton");
     clearButton->click();
     QCOMPARE(labelInput->text(), QString(""));
     QCOMPARE(amountInput->value(), Amount::zero());
     QCOMPARE(messageInput->text(), QString(""));
 
     // Check addition to history
     int currentRowCount = requestTableModel->rowCount({});
     QCOMPARE(currentRowCount, initialRowCount + 1);
 
     // Check Remove button
     QTableView *table =
         receiveCoinsDialog.findChild<QTableView *>("recentRequestsView");
     table->selectRow(currentRowCount - 1);
     QPushButton *removeRequestButton =
         receiveCoinsDialog.findChild<QPushButton *>("removeRequestButton");
     removeRequestButton->click();
     QCOMPARE(requestTableModel->rowCount({}), currentRowCount - 1);
 }
 
 } // namespace
 
 void WalletTests::walletTests() {
 #ifdef Q_OS_MAC
     if (QApplication::platformName() == "minimal") {
         // Disable for mac on "minimal" platform to avoid crashes inside the Qt
         // framework when it tries to look up unimplemented cocoa functions,
         // and fails to handle returned nulls
         // (https://bugreports.qt.io/browse/QTBUG-49686).
         QWARN("Skipping WalletTests on mac build with 'minimal' platform set "
               "due to Qt bugs. To run AppTests, invoke with 'test_bitcoin-qt "
               "-platform cocoa' on mac, or else use a linux or windows build.");
         return;
     }
 #endif
     TestGUI();
 }
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 829c7c4630..fb33f9f650 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -1,1705 +1,1710 @@
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <chain.h>
 #include <config.h>
 #include <core_io.h>
 #include <interfaces/chain.h>
 #include <key_io.h>
 #include <merkleblock.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
 #include <script/script.h>
 #include <script/standard.h>
 #include <sync.h>
 #include <util/system.h>
 #include <util/time.h>
 #include <validation.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/wallet.h>
 
 #include <boost/algorithm/string.hpp>
 
 #include <univalue.h>
 
 #include <cstdint>
 
 static std::string EncodeDumpString(const std::string &str) {
     std::stringstream ret;
     for (const uint8_t c : str) {
         if (c <= 32 || c >= 128 || c == '%') {
             ret << '%' << HexStr(&c, &c + 1);
         } else {
             ret << c;
         }
     }
     return ret.str();
 }
 
 static std::string DecodeDumpString(const std::string &str) {
     std::stringstream ret;
     for (unsigned int pos = 0; pos < str.length(); pos++) {
         uint8_t c = str[pos];
         if (c == '%' && pos + 2 < str.length()) {
             c = (((str[pos + 1] >> 6) * 9 + ((str[pos + 1] - '0') & 15)) << 4) |
                 ((str[pos + 2] >> 6) * 9 + ((str[pos + 2] - '0') & 15));
             pos += 2;
         }
         ret << c;
     }
     return ret.str();
 }
 
 bool GetWalletAddressesForKey(const Config &config, CWallet *const pwallet,
                               const CKeyID &keyid, std::string &strAddr,
                               std::string &strLabel) {
     bool fLabelFound = false;
     CKey key;
     pwallet->GetKey(keyid, key);
     for (const auto &dest : GetAllDestinationsForKey(key.GetPubKey())) {
         if (pwallet->mapAddressBook.count(dest)) {
             if (!strAddr.empty()) {
                 strAddr += ",";
             }
             strAddr += EncodeDestination(dest, config);
             strLabel = EncodeDumpString(pwallet->mapAddressBook[dest].name);
             fLabelFound = true;
         }
     }
     if (!fLabelFound) {
         strAddr = EncodeDestination(
             GetDestinationForKey(key.GetPubKey(),
                                  pwallet->m_default_address_type),
             config);
     }
     return fLabelFound;
 }
 
 static const int64_t TIMESTAMP_MIN = 0;
 
 static void RescanWallet(CWallet &wallet, const WalletRescanReserver &reserver,
                          int64_t time_begin = TIMESTAMP_MIN,
                          bool update = true) {
     int64_t scanned_time = wallet.RescanFromTime(time_begin, reserver, update);
     if (wallet.IsAbortingRescan()) {
         throw JSONRPCError(RPC_MISC_ERROR, "Rescan aborted by user.");
     } else if (scanned_time > time_begin) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Rescan was unable to fully rescan the blockchain. "
                            "Some transactions may be missing.");
     }
 }
 
 UniValue importprivkey(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 3) {
         throw std::runtime_error(
             RPCHelpMan{"importprivkey",
                        "\nAdds a private key (as returned by dumpprivkey) to "
                        "your wallet. Requires a new wallet backup.\n",
                        {
                            {"privkey", RPCArg::Type::STR, false},
                            {"label", RPCArg::Type::STR, true},
                            {"rescan", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             "Hint: use importmulti to import more than one private key.\n"
             "\nArguments:\n"
             "1. \"privkey\"   (string, required) The private key (see "
             "dumpprivkey)\n"
             "2. \"label\"            (string, optional, default=\"\") An "
             "optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan "
             "the wallet for transactions\n"
             "\nNote: This call can take minutes to complete if rescan is true, "
             "during that time, other rpc calls\n"
             "may report that the imported key exists but related transactions "
             "are still missing, leading to temporarily incorrect/bogus "
             "balances and unspent outputs until rescan completes.\n"
             "\nExamples:\n"
             "\nDump a private key\n" +
             HelpExampleCli("dumpprivkey", "\"myaddress\"") +
             "\nImport the private key with rescan\n" +
             HelpExampleCli("importprivkey", "\"mykey\"") +
             "\nImport using a label and without rescan\n" +
             HelpExampleCli("importprivkey", "\"mykey\" \"testing\" false") +
             "\nImport using default blank label and without rescan\n" +
             HelpExampleCli("importprivkey", "\"mykey\" \"\" false") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("importprivkey", "\"mykey\", \"testing\", false"));
     }
 
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Cannot import private keys to a wallet with "
                            "private keys disabled");
     }
 
     WalletRescanReserver reserver(pwallet);
     bool fRescan = true;
     {
         auto locked_chain = pwallet->chain().lock();
         LOCK(pwallet->cs_wallet);
 
         EnsureWalletIsUnlocked(pwallet);
 
         std::string strSecret = request.params[0].get_str();
         std::string strLabel = "";
         if (!request.params[1].isNull()) {
             strLabel = request.params[1].get_str();
         }
 
         // Whether to perform rescan after import
         if (!request.params[2].isNull()) {
             fRescan = request.params[2].get_bool();
         }
 
         if (fRescan && fPruneMode) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "Rescan is disabled in pruned mode");
         }
 
         if (fRescan && !reserver.reserve()) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "Wallet is currently rescanning. Abort existing "
                                "rescan or wait.");
         }
 
         CKey key = DecodeSecret(strSecret);
         if (!key.IsValid()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Invalid private key encoding");
         }
 
         CPubKey pubkey = key.GetPubKey();
         assert(key.VerifyPubKey(pubkey));
         CKeyID vchAddress = pubkey.GetID();
         {
             pwallet->MarkDirty();
             // We don't know which corresponding address will be used; label
             // them all
             for (const auto &dest : GetAllDestinationsForKey(pubkey)) {
                 pwallet->SetAddressBook(dest, strLabel, "receive");
             }
 
             // Don't throw error in case a key is already there
             if (pwallet->HaveKey(vchAddress)) {
                 return NullUniValue;
             }
 
             pwallet->LearnAllRelatedScripts(pubkey);
 
             // whenever a key is imported, we need to scan the whole chain
             pwallet->UpdateTimeFirstKey(1);
             pwallet->mapKeyMetadata[vchAddress].nCreateTime = 1;
 
             if (!pwallet->AddKeyPubKey(key, pubkey)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding key to wallet");
             }
         }
     }
     if (fRescan) {
         RescanWallet(*pwallet, reserver);
     }
 
     return NullUniValue;
 }
 
 UniValue abortrescan(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 0) {
         throw std::runtime_error(
             RPCHelpMan{"abortrescan",
                        "\nStops current wallet rescan triggered by "
                        "an RPC call, e.g. by an importprivkey call.\n",
                        {}}
                 .ToString() +
             "\nExamples:\n"
             "\nImport a private key\n" +
             HelpExampleCli("importprivkey", "\"mykey\"") +
             "\nAbort the running wallet rescan\n" +
             HelpExampleCli("abortrescan", "") + "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("abortrescan", ""));
     }
 
     if (!pwallet->IsScanning() || pwallet->IsAbortingRescan()) {
         return false;
     }
     pwallet->AbortRescan();
     return true;
 }
 
 static void ImportAddress(CWallet *, const CTxDestination &dest,
                           const std::string &strLabel);
 static void ImportScript(CWallet *const pwallet, const CScript &script,
                          const std::string &strLabel, bool isRedeemScript)
     EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet) {
     if (!isRedeemScript && ::IsMine(*pwallet, script) == ISMINE_SPENDABLE) {
         throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already contains the "
                                              "private key for this address or "
                                              "script");
     }
 
     pwallet->MarkDirty();
 
     if (!pwallet->HaveWatchOnly(script) &&
         !pwallet->AddWatchOnly(script, 0 /* nCreateTime */)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
     }
 
     if (isRedeemScript) {
         const CScriptID id(script);
         if (!pwallet->HaveCScript(id) && !pwallet->AddCScript(script)) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "Error adding p2sh redeemScript to wallet");
         }
         ImportAddress(pwallet, id, strLabel);
     } else {
         CTxDestination destination;
         if (ExtractDestination(script, destination)) {
             pwallet->SetAddressBook(destination, strLabel, "receive");
         }
     }
 }
 
 static void ImportAddress(CWallet *const pwallet, const CTxDestination &dest,
                           const std::string &strLabel)
     EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet) {
     CScript script = GetScriptForDestination(dest);
     ImportScript(pwallet, script, strLabel, false);
     // add to address book or update label
     if (IsValidDestination(dest)) {
         pwallet->SetAddressBook(dest, strLabel, "receive");
     }
 }
 
 UniValue importaddress(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 4) {
         throw std::runtime_error(
             RPCHelpMan{"importaddress",
                        "\nAdds an address or script (in hex) that can be "
                        "watched as if it were in your wallet but cannot be "
                        "used to spend. Requires a new wallet backup.\n",
                        {
                            {"address", RPCArg::Type::STR, false},
                            {"label", RPCArg::Type::STR, true},
                            {"rescan", RPCArg::Type::BOOL, true},
                            {"p2sh", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"address\"          (string, required) The Bitcoin address "
             "(or hex-encoded script)\n"
             "2. \"label\"            (string, optional, default=\"\") An "
             "optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan "
             "the wallet for transactions\n"
             "4. p2sh                 (boolean, optional, default=false) Add "
             "the P2SH version of the script as well\n"
             "\nNote: This call can take minutes to complete if rescan is true, "
             "during that time, other rpc calls\n"
             "may report that the imported address exists but related "
             "transactions are still missing, leading to temporarily "
             "incorrect/bogus balances and unspent outputs until rescan "
             "completes.\n"
             "If you have the full public key, you should call importpubkey "
             "instead of this.\n"
             "\nNote: If you import a non-standard raw script in hex form, "
             "outputs sending to it will be treated\n"
             "as change, and not show up in many RPCs.\n"
             "\nExamples:\n"
             "\nImport an address with rescan\n" +
             HelpExampleCli("importaddress", "\"myaddress\"") +
             "\nImport using a label without rescan\n" +
             HelpExampleCli("importaddress", "\"myaddress\" \"testing\" false") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("importaddress",
                            "\"myaddress\", \"testing\", false"));
     }
 
     std::string strLabel;
     if (!request.params[1].isNull()) {
         strLabel = request.params[1].get_str();
     }
 
     // Whether to perform rescan after import
     bool fRescan = true;
     if (!request.params[2].isNull()) {
         fRescan = request.params[2].get_bool();
     }
 
     if (fRescan && fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Rescan is disabled in pruned mode");
     }
 
     WalletRescanReserver reserver(pwallet);
     if (fRescan && !reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
     // Whether to import a p2sh version, too
     bool fP2SH = false;
     if (!request.params[3].isNull()) {
         fP2SH = request.params[3].get_bool();
     }
 
     {
         auto locked_chain = pwallet->chain().lock();
         LOCK(pwallet->cs_wallet);
 
         CTxDestination dest = DecodeDestination(request.params[0].get_str(),
                                                 config.GetChainParams());
         if (IsValidDestination(dest)) {
             if (fP2SH) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Cannot use the p2sh flag with an address - "
                                    "use a script instead");
             }
             ImportAddress(pwallet, dest, strLabel);
         } else if (IsHex(request.params[0].get_str())) {
             std::vector<uint8_t> data(ParseHex(request.params[0].get_str()));
             ImportScript(pwallet, CScript(data.begin(), data.end()), strLabel,
                          fP2SH);
         } else {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Invalid Bitcoin address or script");
         }
     }
     if (fRescan) {
         RescanWallet(*pwallet, reserver);
         pwallet->ReacceptWalletTransactions();
     }
 
     return NullUniValue;
 }
 
 UniValue importprunedfunds(const Config &config,
                            const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 2) {
         throw std::runtime_error(
             RPCHelpMan{"importprunedfunds",
                        "\nImports funds without rescan. Corresponding address "
                        "or script must previously be included in wallet. Aimed "
                        "towards pruned wallets. The end-user is responsible to "
                        "import additional transactions that subsequently spend "
                        "the imported outputs or rescan after the point in the "
                        "blockchain the transaction is included.\n",
                        {
                            {"rawtransaction", RPCArg::Type::STR_HEX, false},
                            {"txoutproof", RPCArg::Type::STR_HEX, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"rawtransaction\" (string, required) A raw transaction in hex "
             "funding an already-existing address in wallet\n"
             "2. \"txoutproof\"     (string, required) The hex output from "
             "gettxoutproof that contains the transaction\n");
     }
 
     CMutableTransaction tx;
     if (!DecodeHexTx(tx, request.params[0].get_str())) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
     }
     uint256 txid = tx.GetId();
     CWalletTx wtx(pwallet, MakeTransactionRef(std::move(tx)));
 
     CDataStream ssMB(ParseHexV(request.params[1], "proof"), SER_NETWORK,
                      PROTOCOL_VERSION);
     CMerkleBlock merkleBlock;
     ssMB >> merkleBlock;
 
     // Search partial merkle tree in proof for our transaction and index in
     // valid block
     std::vector<uint256> vMatch;
     std::vector<size_t> vIndex;
     size_t txnIndex = 0;
     if (merkleBlock.txn.ExtractMatches(vMatch, vIndex) ==
         merkleBlock.header.hashMerkleRoot) {
         auto locked_chain = pwallet->chain().lock();
-        const CBlockIndex *pindex =
-            LookupBlockIndex(merkleBlock.header.GetHash());
-        if (!pindex || !::ChainActive().Contains(pindex)) {
+        if (locked_chain->getBlockHeight(merkleBlock.header.GetHash()) ==
+            nullopt) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Block not found in chain");
         }
 
         std::vector<uint256>::const_iterator it;
         if ((it = std::find(vMatch.begin(), vMatch.end(), txid)) ==
             vMatch.end()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Transaction given doesn't exist in proof");
         }
 
         txnIndex = vIndex[it - vMatch.begin()];
     } else {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Something wrong with merkleblock");
     }
 
     wtx.nIndex = txnIndex;
     wtx.hashBlock = merkleBlock.header.GetHash();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     if (pwallet->IsMine(*wtx.tx)) {
         pwallet->AddToWallet(wtx, false);
         return NullUniValue;
     }
 
     throw JSONRPCError(
         RPC_INVALID_ADDRESS_OR_KEY,
         "No addresses in wallet correspond to included transaction");
 }
 
 UniValue removeprunedfunds(const Config &config,
                            const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             RPCHelpMan{
                 "removeprunedfunds",
                 "\nDeletes the specified transaction from the wallet. Meant "
                 "for use with pruned wallets and as a companion to "
                 "importprunedfunds. This will affect wallet balances.\n",
                 {
                     {"txid", RPCArg::Type::STR_HEX, false},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"txid\"           (string, required) The hex-encoded id of "
             "the transaction you are deleting\n"
             "\nExamples:\n" +
             HelpExampleCli("removeprunedfunds", "\"a8d0c0184dde994a09ec054286f1"
                                                 "ce581bebf46446a512166eae762873"
                                                 "4ea0a5\"") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("removeprunedfunds",
                            "\"a8d0c0184dde994a09ec054286f1ce581bebf46446a512166"
                            "eae7628734ea0a5\""));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     TxId txid(ParseHashV(request.params[0], "txid"));
     std::vector<TxId> txIds;
     txIds.push_back(txid);
     std::vector<TxId> txIdsOut;
 
     if (pwallet->ZapSelectTx(txIds, txIdsOut) != DBErrors::LOAD_OK) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Could not properly delete the transaction.");
     }
 
     if (txIdsOut.empty()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Transaction does not exist in wallet.");
     }
 
     return NullUniValue;
 }
 
 UniValue importpubkey(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 4) {
         throw std::runtime_error(
             RPCHelpMan{"importpubkey",
                        "\nAdds a public key (in hex) that can be watched as if "
                        "it were in your wallet but cannot be used to spend. "
                        "Requires a new wallet backup.\n",
                        {
                            {"pubkey", RPCArg::Type::STR, false},
                            {"label", RPCArg::Type::STR, true},
                            {"rescan", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"pubkey\"           (string, required) The hex-encoded public "
             "key\n"
             "2. \"label\"            (string, optional, default=\"\") An "
             "optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan "
             "the wallet for transactions\n"
             "\nNote: This call can take minutes to complete if rescan is true, "
             "during that time, other rpc calls\n"
             "may report that the imported pubkey exists but related "
             "transactions are still missing, leading to temporarily "
             "incorrect/bogus balances and unspent outputs until rescan "
             "completes.\n"
             "\nExamples:\n"
             "\nImport a public key with rescan\n" +
             HelpExampleCli("importpubkey", "\"mypubkey\"") +
             "\nImport using a label without rescan\n" +
             HelpExampleCli("importpubkey", "\"mypubkey\" \"testing\" false") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("importpubkey", "\"mypubkey\", \"testing\", false"));
     }
 
     std::string strLabel;
     if (!request.params[1].isNull()) {
         strLabel = request.params[1].get_str();
     }
 
     // Whether to perform rescan after import
     bool fRescan = true;
     if (!request.params[2].isNull()) {
         fRescan = request.params[2].get_bool();
     }
 
     if (fRescan && fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Rescan is disabled in pruned mode");
     }
 
     WalletRescanReserver reserver(pwallet);
     if (fRescan && !reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
     if (!IsHex(request.params[0].get_str())) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Pubkey must be a hex string");
     }
     std::vector<uint8_t> data(ParseHex(request.params[0].get_str()));
     CPubKey pubKey(data.begin(), data.end());
     if (!pubKey.IsFullyValid()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Pubkey is not a valid public key");
     }
 
     {
         auto locked_chain = pwallet->chain().lock();
         LOCK(pwallet->cs_wallet);
 
         for (const auto &dest : GetAllDestinationsForKey(pubKey)) {
             ImportAddress(pwallet, dest, strLabel);
         }
         ImportScript(pwallet, GetScriptForRawPubKey(pubKey), strLabel, false);
         pwallet->LearnAllRelatedScripts(pubKey);
     }
     if (fRescan) {
         RescanWallet(*pwallet, reserver);
         pwallet->ReacceptWalletTransactions();
     }
 
     return NullUniValue;
 }
 
 UniValue importwallet(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             RPCHelpMan{
                 "importwallet",
                 "\nImports keys from a wallet dump file (see dumpwallet). "
                 "Requires a new wallet backup to include imported keys.\n",
                 {
                     {"filename", RPCArg::Type::STR, false},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"filename\"    (string, required) The wallet file\n"
             "\nExamples:\n"
             "\nDump the wallet\n" +
             HelpExampleCli("dumpwallet", "\"test\"") + "\nImport the wallet\n" +
             HelpExampleCli("importwallet", "\"test\"") +
             "\nImport using the json rpc call\n" +
             HelpExampleRpc("importwallet", "\"test\""));
     }
 
     if (fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Importing wallets is disabled in pruned mode");
     }
 
     WalletRescanReserver reserver(pwallet);
     if (!reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
     int64_t nTimeBegin = 0;
     bool fGood = true;
     {
         auto locked_chain = pwallet->chain().lock();
         LOCK(pwallet->cs_wallet);
 
         EnsureWalletIsUnlocked(pwallet);
 
         fsbridge::ifstream file;
         file.open(request.params[0].get_str(), std::ios::in | std::ios::ate);
         if (!file.is_open()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Cannot open wallet dump file");
         }
-        nTimeBegin = ::ChainActive().Tip()->GetBlockTime();
+        Optional<int> tip_height = locked_chain->getHeight();
+        nTimeBegin = tip_height ? locked_chain->getBlockTime(*tip_height) : 0;
 
         int64_t nFilesize = std::max<int64_t>(1, file.tellg());
         file.seekg(0, file.beg);
 
         // Use uiInterface.ShowProgress instead of pwallet.ShowProgress because
         // pwallet.ShowProgress has a cancel button tied to AbortRescan which we
         // don't want for this progress bar showing the import progress.
         // uiInterface.ShowProgress does not have a cancel button.
 
         // show progress dialog in GUI
         uiInterface.ShowProgress(
             strprintf("%s " + _("Importing..."), pwallet->GetDisplayName()), 0,
             false);
         std::vector<std::tuple<CKey, int64_t, bool, std::string>> keys;
         std::vector<std::pair<CScript, int64_t>> scripts;
         while (file.good()) {
             uiInterface.ShowProgress(
                 "",
                 std::max(1, std::min<int>(50, 100 * double(file.tellg()) /
                                                   double(nFilesize))),
                 false);
             std::string line;
             std::getline(file, line);
             if (line.empty() || line[0] == '#') {
                 continue;
             }
 
             std::vector<std::string> vstr;
             boost::split(vstr, line, boost::is_any_of(" "));
             if (vstr.size() < 2) {
                 continue;
             }
             CKey key = DecodeSecret(vstr[0]);
             if (key.IsValid()) {
                 int64_t nTime = ParseISO8601DateTime(vstr[1]);
                 std::string strLabel;
                 bool fLabel = true;
                 for (size_t nStr = 2; nStr < vstr.size(); nStr++) {
                     if (vstr[nStr].front() == '#') {
                         break;
                     }
                     if (vstr[nStr] == "change=1") {
                         fLabel = false;
                     }
                     if (vstr[nStr] == "reserve=1") {
                         fLabel = false;
                     }
                     if (vstr[nStr].substr(0, 6) == "label=") {
                         strLabel = DecodeDumpString(vstr[nStr].substr(6));
                         fLabel = true;
                     }
                 }
                 keys.push_back(std::make_tuple(key, nTime, fLabel, strLabel));
             } else if (IsHex(vstr[0])) {
                 std::vector<uint8_t> vData(ParseHex(vstr[0]));
                 CScript script = CScript(vData.begin(), vData.end());
                 int64_t birth_time = ParseISO8601DateTime(vstr[1]);
                 scripts.push_back(
                     std::pair<CScript, int64_t>(script, birth_time));
             }
         }
         file.close();
         // We now know whether we are importing private keys, so we can error if
         // private keys are disabled
         if (keys.size() > 0 &&
             pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
             // hide progress dialog in GUI
             uiInterface.ShowProgress("", 100, false);
             throw JSONRPCError(
                 RPC_WALLET_ERROR,
                 "Importing wallets is disabled when private keys are disabled");
         }
         double total = double(keys.size() + scripts.size());
         double progress = 0;
         for (const auto &key_tuple : keys) {
             uiInterface.ShowProgress(
                 "",
                 std::max(50, std::min<int>(75, 100 * progress / total) + 50),
                 false);
             const CKey &key = std::get<0>(key_tuple);
             int64_t time = std::get<1>(key_tuple);
             bool has_label = std::get<2>(key_tuple);
             std::string label = std::get<3>(key_tuple);
 
             CPubKey pubkey = key.GetPubKey();
             assert(key.VerifyPubKey(pubkey));
             CKeyID keyid = pubkey.GetID();
             if (pwallet->HaveKey(keyid)) {
                 pwallet->WalletLogPrintf(
                     "Skipping import of %s (key already present)\n",
                     EncodeDestination(keyid, config));
                 continue;
             }
             pwallet->WalletLogPrintf("Importing %s...\n",
                                      EncodeDestination(keyid, config));
             if (!pwallet->AddKeyPubKey(key, pubkey)) {
                 fGood = false;
                 continue;
             }
             pwallet->mapKeyMetadata[keyid].nCreateTime = time;
             if (has_label) {
                 pwallet->SetAddressBook(keyid, label, "receive");
             }
             nTimeBegin = std::min(nTimeBegin, time);
             progress++;
         }
         for (const auto &script_pair : scripts) {
             uiInterface.ShowProgress(
                 "",
                 std::max(50, std::min<int>(75, 100 * progress / total) + 50),
                 false);
             const CScript &script = script_pair.first;
             int64_t time = script_pair.second;
             CScriptID id(script);
             if (pwallet->HaveCScript(id)) {
                 pwallet->WalletLogPrintf(
                     "Skipping import of %s (script already present)\n",
                     HexStr(script));
                 continue;
             }
             if (!pwallet->AddCScript(script)) {
                 pwallet->WalletLogPrintf("Error importing script %s\n",
                                          HexStr(script));
                 fGood = false;
                 continue;
             }
             if (time > 0) {
                 pwallet->m_script_metadata[id].nCreateTime = time;
                 nTimeBegin = std::min(nTimeBegin, time);
             }
             progress++;
         }
         // hide progress dialog in GUI
         uiInterface.ShowProgress("", 100, false);
         pwallet->UpdateTimeFirstKey(nTimeBegin);
     }
     // hide progress dialog in GUI
     uiInterface.ShowProgress("", 100, false);
     RescanWallet(*pwallet, reserver, nTimeBegin, false /* update */);
     pwallet->MarkDirty();
 
     if (!fGood) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error adding some keys/scripts to wallet");
     }
 
     return NullUniValue;
 }
 
 UniValue dumpprivkey(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             RPCHelpMan{"dumpprivkey",
                        "\nReveals the private key corresponding to 'address'.\n"
                        "Then the importprivkey can be used with this output\n",
                        {
                            {"address", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"address\"   (string, required) The bitcoin address for the "
             "private key\n"
             "\nResult:\n"
             "\"key\"                (string) The private key\n"
             "\nExamples:\n" +
             HelpExampleCli("dumpprivkey", "\"myaddress\"") +
             HelpExampleCli("importprivkey", "\"mykey\"") +
             HelpExampleRpc("dumpprivkey", "\"myaddress\""));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
     std::string strAddress = request.params[0].get_str();
     CTxDestination dest =
         DecodeDestination(strAddress, config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address");
     }
     auto keyid = GetKeyForDestination(*pwallet, dest);
     if (keyid.IsNull()) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to a key");
     }
     CKey vchSecret;
     if (!pwallet->GetKey(keyid, vchSecret)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Private key for address " +
                                                  strAddress + " is not known");
     }
     return EncodeSecret(vchSecret);
 }
 
 UniValue dumpwallet(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             RPCHelpMan{"dumpwallet",
                        "\nDumps all wallet keys in a human-readable format to "
                        "a server-side file. This does not allow overwriting "
                        "existing files.\n"
                        "Imported scripts are included in the dumpsfile, but "
                        "corresponding addresses may not be added automatically "
                        "by importwallet.\n"
                        "Note that if your wallet contains keys which are not "
                        "derived from your HD seed (e.g. imported keys), these "
                        "are not covered by\n"
                        "only backing up the seed itself, and must be backed up "
                        "too (e.g. ensure you back up the whole dumpfile).\n",
                        {
                            {"filename", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"filename\"    (string, required) The filename with path "
             "(either absolute or relative to bitcoind)\n"
             "\nResult:\n"
             "{                           (json object)\n"
             "  \"filename\" : {        (string) The filename with full "
             "absolute path\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("dumpwallet", "\"test\"") +
             HelpExampleRpc("dumpwallet", "\"test\""));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
     fs::path filepath = request.params[0].get_str();
     filepath = fs::absolute(filepath);
 
     /**
      * Prevent arbitrary files from being overwritten. There have been reports
      * that users have overwritten wallet files this way:
      * https://github.com/bitcoin/bitcoin/issues/9934
      * It may also avoid other security issues.
      */
     if (fs::exists(filepath)) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            filepath.string() + " already exists. If you are "
                                                "sure this is what you want, "
                                                "move it out of the way first");
     }
 
     fsbridge::ofstream file;
     file.open(filepath);
     if (!file.is_open()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Cannot open wallet dump file");
     }
 
     std::map<CTxDestination, int64_t> mapKeyBirth;
     const std::map<CKeyID, int64_t> &mapKeyPool = pwallet->GetAllReserveKeys();
     pwallet->GetKeyBirthTimes(*locked_chain, mapKeyBirth);
 
     std::set<CScriptID> scripts = pwallet->GetCScripts();
     // TODO: include scripts in GetKeyBirthTimes() output instead of separate
 
     // sort time/key pairs
     std::vector<std::pair<int64_t, CKeyID>> vKeyBirth;
     for (const auto &entry : mapKeyBirth) {
         if (const CKeyID *keyID = boost::get<CKeyID>(&entry.first)) {
             // set and test
             vKeyBirth.push_back(std::make_pair(entry.second, *keyID));
         }
     }
     mapKeyBirth.clear();
     std::sort(vKeyBirth.begin(), vKeyBirth.end());
 
     // produce output
     file << strprintf("# Wallet dump created by Bitcoin %s\n", CLIENT_BUILD);
     file << strprintf("# * Created on %s\n", FormatISO8601DateTime(GetTime()));
+    const Optional<int> tip_height = locked_chain->getHeight();
     file << strprintf("# * Best block at time of backup was %i (%s),\n",
-                      ::ChainActive().Height(),
-                      ::ChainActive().Tip()->GetBlockHash().ToString());
-    file << strprintf(
-        "#   mined on %s\n",
-        FormatISO8601DateTime(::ChainActive().Tip()->GetBlockTime()));
+                      tip_height.value_or(-1),
+                      tip_height
+                          ? locked_chain->getBlockHash(*tip_height).ToString()
+                          : "(missing block hash)");
+    file << strprintf("#   mined on %s\n",
+                      tip_height ? FormatISO8601DateTime(
+                                       locked_chain->getBlockTime(*tip_height))
+                                 : "(missing block time)");
     file << "\n";
 
     // add the base58check encoded extended master if the wallet uses HD
     CKeyID seed_id = pwallet->GetHDChain().seed_id;
     if (!seed_id.IsNull()) {
         CKey seed;
         if (pwallet->GetKey(seed_id, seed)) {
             CExtKey masterKey;
             masterKey.SetSeed(seed.begin(), seed.size());
 
             file << "# extended private masterkey: " << EncodeExtKey(masterKey)
                  << "\n\n";
         }
     }
     for (std::vector<std::pair<int64_t, CKeyID>>::const_iterator it =
              vKeyBirth.begin();
          it != vKeyBirth.end(); it++) {
         const CKeyID &keyid = it->second;
         std::string strTime = FormatISO8601DateTime(it->first);
         std::string strAddr;
         std::string strLabel;
         CKey key;
         if (pwallet->GetKey(keyid, key)) {
             file << strprintf("%s %s ", EncodeSecret(key), strTime);
             if (GetWalletAddressesForKey(config, pwallet, keyid, strAddr,
                                          strLabel)) {
                 file << strprintf("label=%s", strLabel);
             } else if (keyid == seed_id) {
                 file << "hdseed=1";
             } else if (mapKeyPool.count(keyid)) {
                 file << "reserve=1";
             } else if (pwallet->mapKeyMetadata[keyid].hdKeypath == "s") {
                 file << "inactivehdseed=1";
             } else {
                 file << "change=1";
             }
             file << strprintf(
                 " # addr=%s%s\n", strAddr,
                 (pwallet->mapKeyMetadata[keyid].hdKeypath.size() > 0
                      ? " hdkeypath=" + pwallet->mapKeyMetadata[keyid].hdKeypath
                      : ""));
         }
     }
     file << "\n";
     for (const CScriptID &scriptid : scripts) {
         CScript script;
         std::string create_time = "0";
         std::string address = EncodeDestination(scriptid, config);
         // get birth times for scripts with metadata
         auto it = pwallet->m_script_metadata.find(scriptid);
         if (it != pwallet->m_script_metadata.end()) {
             create_time = FormatISO8601DateTime(it->second.nCreateTime);
         }
         if (pwallet->GetCScript(scriptid, script)) {
             file << strprintf("%s %s script=1",
                               HexStr(script.begin(), script.end()),
                               create_time);
             file << strprintf(" # addr=%s\n", address);
         }
     }
     file << "\n";
     file << "# End of dump\n";
     file.close();
 
     UniValue reply(UniValue::VOBJ);
     reply.pushKV("filename", filepath.string());
 
     return reply;
 }
 
 static UniValue ProcessImport(CWallet *const pwallet, const UniValue &data,
                               const int64_t timestamp)
     EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet) {
     try {
         bool success = false;
 
         // Required fields.
         const UniValue &scriptPubKey = data["scriptPubKey"];
 
         // Should have script or JSON with "address".
         if (!(scriptPubKey.getType() == UniValue::VOBJ &&
               scriptPubKey.exists("address")) &&
             !(scriptPubKey.getType() == UniValue::VSTR)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid scriptPubKey");
         }
 
         // Optional fields.
         const std::string &strRedeemScript =
             data.exists("redeemscript") ? data["redeemscript"].get_str() : "";
         const UniValue &pubKeys =
             data.exists("pubkeys") ? data["pubkeys"].get_array() : UniValue();
         const UniValue &keys =
             data.exists("keys") ? data["keys"].get_array() : UniValue();
         const bool internal =
             data.exists("internal") ? data["internal"].get_bool() : false;
         const bool watchOnly =
             data.exists("watchonly") ? data["watchonly"].get_bool() : false;
         const std::string &label =
             data.exists("label") && !internal ? data["label"].get_str() : "";
 
         // If private keys are disabled, abort if private keys are being
         // imported
         if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS) &&
             !keys.isNull()) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "Cannot import private keys to a wallet with "
                                "private keys disabled");
         }
 
         bool isScript = scriptPubKey.getType() == UniValue::VSTR;
         bool isP2SH = strRedeemScript.length() > 0;
         const std::string &output = isScript
                                         ? scriptPubKey.get_str()
                                         : scriptPubKey["address"].get_str();
 
         // Parse the output.
         CScript script;
         CTxDestination dest;
 
         if (!isScript) {
             dest = DecodeDestination(output, pwallet->chainParams);
             if (!IsValidDestination(dest)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Invalid address");
             }
             script = GetScriptForDestination(dest);
         } else {
             if (!IsHex(output)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Invalid scriptPubKey");
             }
 
             std::vector<uint8_t> vData(ParseHex(output));
             script = CScript(vData.begin(), vData.end());
         }
 
         // Watchonly and private keys
         if (watchOnly && keys.size()) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Incompatibility found between watchonly and keys");
         }
 
         // Internal + Label
         if (internal && data.exists("label")) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Incompatibility found between internal and label");
         }
 
         // Not having Internal + Script
         if (!internal && isScript) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Internal must be set for hex scriptPubKey");
         }
 
         // Keys / PubKeys size check.
         if (!isP2SH &&
             (keys.size() > 1 || pubKeys.size() > 1)) { // Address / scriptPubKey
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "More than private key given for one address");
         }
 
         // Invalid P2SH redeemScript
         if (isP2SH && !IsHex(strRedeemScript)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Invalid redeem script");
         }
 
         // Process. //
 
         // P2SH
         if (isP2SH) {
             // Import redeem script.
             std::vector<uint8_t> vData(ParseHex(strRedeemScript));
             CScript redeemScript = CScript(vData.begin(), vData.end());
 
             // Invalid P2SH address
             if (!script.IsPayToScriptHash()) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Invalid P2SH address / script");
             }
 
             pwallet->MarkDirty();
 
             if (!pwallet->AddWatchOnly(redeemScript, timestamp)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding address to wallet");
             }
 
             CScriptID redeem_id(redeemScript);
             if (!pwallet->HaveCScript(redeem_id) &&
                 !pwallet->AddCScript(redeemScript)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding p2sh redeemScript to wallet");
             }
 
             CScript redeemDestination = GetScriptForDestination(redeem_id);
 
             if (::IsMine(*pwallet, redeemDestination) == ISMINE_SPENDABLE) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "The wallet already contains the private "
                                    "key for this address or script");
             }
 
             pwallet->MarkDirty();
 
             if (!pwallet->AddWatchOnly(redeemDestination, timestamp)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding address to wallet");
             }
 
             // if not internal add to address book or update label
             if (!internal) {
                 assert(IsValidDestination(dest));
                 pwallet->SetAddressBook(dest, label, "receive");
             }
 
             // Import private keys.
             if (keys.size()) {
                 for (size_t i = 0; i < keys.size(); i++) {
                     const std::string &privkey = keys[i].get_str();
 
                     CKey key = DecodeSecret(privkey);
 
                     if (!key.IsValid()) {
                         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                            "Invalid private key encoding");
                     }
 
                     CPubKey pubkey = key.GetPubKey();
                     assert(key.VerifyPubKey(pubkey));
 
                     CKeyID vchAddress = pubkey.GetID();
                     pwallet->MarkDirty();
                     pwallet->SetAddressBook(vchAddress, label, "receive");
 
                     if (pwallet->HaveKey(vchAddress)) {
                         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                            "Already have this key");
                     }
 
                     pwallet->mapKeyMetadata[vchAddress].nCreateTime = timestamp;
 
                     if (!pwallet->AddKeyPubKey(key, pubkey)) {
                         throw JSONRPCError(RPC_WALLET_ERROR,
                                            "Error adding key to wallet");
                     }
 
                     pwallet->UpdateTimeFirstKey(timestamp);
                 }
             }
 
             success = true;
         } else {
             // Import public keys.
             if (pubKeys.size() && keys.size() == 0) {
                 const std::string &strPubKey = pubKeys[0].get_str();
 
                 if (!IsHex(strPubKey)) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Pubkey must be a hex string");
                 }
 
                 std::vector<uint8_t> vData(ParseHex(strPubKey));
                 CPubKey pubKey(vData.begin(), vData.end());
 
                 if (!pubKey.IsFullyValid()) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Pubkey is not a valid public key");
                 }
 
                 CTxDestination pubkey_dest = pubKey.GetID();
 
                 // Consistency check.
                 if (!isScript && !(pubkey_dest == dest)) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Consistency check failed");
                 }
 
                 // Consistency check.
                 if (isScript) {
                     CTxDestination destination;
 
                     if (ExtractDestination(script, destination)) {
                         if (!(destination == pubkey_dest)) {
                             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                                "Consistency check failed");
                         }
                     }
                 }
 
                 CScript pubKeyScript = GetScriptForDestination(pubkey_dest);
 
                 if (::IsMine(*pwallet, pubKeyScript) == ISMINE_SPENDABLE) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->MarkDirty();
 
                 if (!pwallet->AddWatchOnly(pubKeyScript, timestamp)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding address to wallet");
                 }
 
                 // add to address book or update label
                 if (IsValidDestination(pubkey_dest)) {
                     pwallet->SetAddressBook(pubkey_dest, label, "receive");
                 }
 
                 // TODO Is this necessary?
                 CScript scriptRawPubKey = GetScriptForRawPubKey(pubKey);
 
                 if (::IsMine(*pwallet, scriptRawPubKey) == ISMINE_SPENDABLE) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->MarkDirty();
 
                 if (!pwallet->AddWatchOnly(scriptRawPubKey, timestamp)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding address to wallet");
                 }
 
                 success = true;
             }
 
             // Import private keys.
             if (keys.size()) {
                 const std::string &strPrivkey = keys[0].get_str();
 
                 // Checks.
                 CKey key = DecodeSecret(strPrivkey);
 
                 if (!key.IsValid()) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Invalid private key encoding");
                 }
 
                 CPubKey pubKey = key.GetPubKey();
                 assert(key.VerifyPubKey(pubKey));
 
                 CTxDestination pubkey_dest = pubKey.GetID();
 
                 // Consistency check.
                 if (!isScript && !(pubkey_dest == dest)) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Consistency check failed");
                 }
 
                 // Consistency check.
                 if (isScript) {
                     CTxDestination destination;
 
                     if (ExtractDestination(script, destination)) {
                         if (!(destination == pubkey_dest)) {
                             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                                "Consistency check failed");
                         }
                     }
                 }
 
                 CKeyID vchAddress = pubKey.GetID();
                 pwallet->MarkDirty();
                 pwallet->SetAddressBook(vchAddress, label, "receive");
 
                 if (pwallet->HaveKey(vchAddress)) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->mapKeyMetadata[vchAddress].nCreateTime = timestamp;
 
                 if (!pwallet->AddKeyPubKey(key, pubKey)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding key to wallet");
                 }
 
                 pwallet->UpdateTimeFirstKey(timestamp);
 
                 success = true;
             }
 
             // Import scriptPubKey only.
             if (pubKeys.size() == 0 && keys.size() == 0) {
                 if (::IsMine(*pwallet, script) == ISMINE_SPENDABLE) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->MarkDirty();
 
                 if (!pwallet->AddWatchOnly(script, timestamp)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding address to wallet");
                 }
 
                 if (scriptPubKey.getType() == UniValue::VOBJ) {
                     // add to address book or update label
                     if (IsValidDestination(dest)) {
                         pwallet->SetAddressBook(dest, label, "receive");
                     }
                 }
 
                 success = true;
             }
         }
 
         UniValue result = UniValue(UniValue::VOBJ);
         result.pushKV("success", UniValue(success));
         return result;
     } catch (const UniValue &e) {
         UniValue result = UniValue(UniValue::VOBJ);
         result.pushKV("success", UniValue(false));
         result.pushKV("error", e);
         return result;
     } catch (...) {
         UniValue result = UniValue(UniValue::VOBJ);
         result.pushKV("success", UniValue(false));
         result.pushKV("error",
                       JSONRPCError(RPC_MISC_ERROR, "Missing required fields"));
         return result;
     }
 }
 
 static int64_t GetImportTimestamp(const UniValue &data, int64_t now) {
     if (data.exists("timestamp")) {
         const UniValue &timestamp = data["timestamp"];
         if (timestamp.isNum()) {
             return timestamp.get_int64();
         } else if (timestamp.isStr() && timestamp.get_str() == "now") {
             return now;
         }
         throw JSONRPCError(RPC_TYPE_ERROR,
                            strprintf("Expected number or \"now\" timestamp "
                                      "value for key. got type %s",
                                      uvTypeName(timestamp.type())));
     }
     throw JSONRPCError(RPC_TYPE_ERROR,
                        "Missing required timestamp field for key");
 }
 
 UniValue importmulti(const Config &config, const JSONRPCRequest &mainRequest) {
     std::shared_ptr<CWallet> const wallet =
         GetWalletForJSONRPCRequest(mainRequest);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, mainRequest.fHelp)) {
         return NullUniValue;
     }
 
     if (mainRequest.fHelp || mainRequest.params.size() < 1 ||
         mainRequest.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{
                 "importmulti",
                 "\nImport addresses/scripts (with private or public keys, "
                 "redeem script (P2SH)), rescanning all addresses in "
                 "one-shot-only (rescan can be disabled via options). Requires "
                 "a new wallet backup.\n\n",
                 {
                     {"requests",
                      RPCArg::Type::ARR,
                      {
                          {"",
                           RPCArg::Type::OBJ,
                           {
                               {
                                   {"scriptPubKey", RPCArg::Type::STR, false},
                                   {"timestamp", RPCArg::Type::NUM, false},
                                   {"redeemscript", RPCArg::Type::STR, true},
                                   {"pubkeys",
                                    RPCArg::Type::ARR,
                                    {
                                        {"pubkey", RPCArg::Type::STR, false},
                                    },
                                    true},
                                   {"keys",
                                    RPCArg::Type::ARR,
                                    {
                                        {"key", RPCArg::Type::STR, false},
                                    },
                                    true},
                                   {"internal", RPCArg::Type::BOOL, true},
                                   {"watchonly", RPCArg::Type::BOOL, true},
                                   {"label", RPCArg::Type::STR, true},
                               },
                           },
                           false},
                      },
                      false,
                      "\"requests\""},
                     {"options",
                      RPCArg::Type::OBJ,
                      {
                          {"rescan", RPCArg::Type::BOOL, true},
                      },
                      true,
                      "\"options\""},
                 }}
                 .ToString() +
             "Arguments:\n"
             "1. requests     (array, required) Data to be imported\n"
             "  [     (array of json objects)\n"
             "    {\n"
             "      \"scriptPubKey\": \"<script>\" | { "
             "\"address\":\"<address>\" }, (string / json, required) Type of "
             "scriptPubKey (string for script, json for address)\n"
             "      \"timestamp\": timestamp | \"now\"                        , "
             "(integer / string, required) Creation time of the key in seconds "
             "since epoch (Jan 1 1970 GMT),\n"
             "                                                              or "
             "the string \"now\" to substitute the current synced blockchain "
             "time. The timestamp of the oldest\n"
             "                                                              key "
             "will determine how far back blockchain rescans need to begin for "
             "missing wallet transactions.\n"
             "                                                              "
             "\"now\" can be specified to bypass scanning, for keys which are "
             "known to never have been used, and\n"
             "                                                              0 "
             "can be specified to scan the entire blockchain. Blocks up to 2 "
             "hours before the earliest key\n"
             "                                                              "
             "creation time of all keys being imported by the importmulti call "
             "will be scanned.\n"
             "      \"redeemscript\": \"<script>\"                            , "
             "(string, optional) Allowed only if the scriptPubKey is a P2SH "
             "address or a P2SH scriptPubKey\n"
             "      \"pubkeys\": [\"<pubKey>\", ... ]                         , "
             "(array, optional) Array of strings giving pubkeys that must occur "
             "in the output or redeemscript\n"
             "      \"keys\": [\"<key>\", ... ]                               , "
             "(array, optional) Array of strings giving private keys whose "
             "corresponding public keys must occur in the output or "
             "redeemscript\n"
             "      \"internal\": <true>                                    , "
             "(boolean, optional, default: false) Stating whether matching "
             "outputs should be treated as not incoming payments aka change\n"
             "      \"watchonly\": <true>                                   , "
             "(boolean, optional, default: false) Stating whether matching "
             "outputs should be considered watched even when they're not "
             "spendable, only allowed if keys are empty\n"
             "      \"label\": <label>                                      , "
             "(string, optional, default: '') Label to assign to the address, "
             "only allowed with internal=false\n"
             "    }\n"
             "  ,...\n"
             "  ]\n"
             "2. options                 (json, optional)\n"
             "  {\n"
             "     \"rescan\": <false>,         (boolean, optional, default: "
             "true) Stating if should rescan the blockchain after all imports\n"
             "  }\n"
             "\nNote: This call can take minutes to complete if rescan is true, "
             "during that time, other rpc calls\n"
             "may report that the imported keys, addresses or scripts exists "
             "but related transactions are still missing.\n"
             "\nExamples:\n" +
             HelpExampleCli(
                 "importmulti",
                 "'[{ \"scriptPubKey\": { \"address\": \"<my address>\" }, "
                 "\"timestamp\":1455191478 }, "
                 "{ \"scriptPubKey\": { \"address\": \"<my 2nd address>\" }, "
                 "\"label\": \"example 2\", \"timestamp\": 1455191480 }]'") +
             HelpExampleCli(
                 "importmulti",
                 "'[{ \"scriptPubKey\": { \"address\": \"<my address>\" }, "
                 "\"timestamp\":1455191478 }]' '{ \"rescan\": false}'") +
 
             "\nResponse is an array with the same size as the input that has "
             "the execution result :\n"
             "  [{ \"success\": true } , { \"success\": false, \"error\": { "
             "\"code\": -1, \"message\": \"Internal Server Error\"} }, ... ]\n");
     }
 
     RPCTypeCheck(mainRequest.params, {UniValue::VARR, UniValue::VOBJ});
 
     const UniValue &requests = mainRequest.params[0];
 
     // Default options
     bool fRescan = true;
 
     if (!mainRequest.params[1].isNull()) {
         const UniValue &options = mainRequest.params[1];
 
         if (options.exists("rescan")) {
             fRescan = options["rescan"].get_bool();
         }
     }
 
     WalletRescanReserver reserver(pwallet);
     if (fRescan && !reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
     int64_t now = 0;
     bool fRunScan = false;
     int64_t nLowestTimestamp = 0;
     UniValue response(UniValue::VARR);
     {
         auto locked_chain = pwallet->chain().lock();
         LOCK(pwallet->cs_wallet);
         EnsureWalletIsUnlocked(pwallet);
 
         // Verify all timestamps are present before importing any keys.
-        now = ::ChainActive().Tip() ? ::ChainActive().Tip()->GetMedianTimePast()
-                                    : 0;
+        const Optional<int> tip_height = locked_chain->getHeight();
+        now =
+            tip_height ? locked_chain->getBlockMedianTimePast(*tip_height) : 0;
         for (const UniValue &data : requests.getValues()) {
             GetImportTimestamp(data, now);
         }
 
         const int64_t minimumTimestamp = 1;
 
-        if (fRescan && ::ChainActive().Tip()) {
-            nLowestTimestamp = ::ChainActive().Tip()->GetBlockTime();
+        if (fRescan && tip_height) {
+            nLowestTimestamp = locked_chain->getBlockTime(*tip_height);
         } else {
             fRescan = false;
         }
 
         for (const UniValue &data : requests.getValues()) {
             const int64_t timestamp =
                 std::max(GetImportTimestamp(data, now), minimumTimestamp);
             const UniValue result = ProcessImport(pwallet, data, timestamp);
             response.push_back(result);
 
             if (!fRescan) {
                 continue;
             }
 
             // If at least one request was successful then allow rescan.
             if (result["success"].get_bool()) {
                 fRunScan = true;
             }
 
             // Get the lowest timestamp.
             if (timestamp < nLowestTimestamp) {
                 nLowestTimestamp = timestamp;
             }
         }
     }
     if (fRescan && fRunScan && requests.size()) {
         int64_t scannedTime = pwallet->RescanFromTime(
             nLowestTimestamp, reserver, true /* update */);
         pwallet->ReacceptWalletTransactions();
 
         if (pwallet->IsAbortingRescan()) {
             throw JSONRPCError(RPC_MISC_ERROR, "Rescan aborted by user.");
         }
         if (scannedTime > nLowestTimestamp) {
             std::vector<UniValue> results = response.getValues();
             response.clear();
             response.setArray();
             size_t i = 0;
             for (const UniValue &request : requests.getValues()) {
                 // If key creation date is within the successfully scanned
                 // range, or if the import result already has an error set, let
                 // the result stand unmodified. Otherwise replace the result
                 // with an error message.
                 if (scannedTime <= GetImportTimestamp(request, now) ||
                     results.at(i).exists("error")) {
                     response.push_back(results.at(i));
                 } else {
                     UniValue result = UniValue(UniValue::VOBJ);
                     result.pushKV("success", UniValue(false));
                     result.pushKV(
                         "error",
                         JSONRPCError(
                             RPC_MISC_ERROR,
                             strprintf(
                                 "Rescan failed for key with creation timestamp "
                                 "%d. There was an error reading a block from "
                                 "time %d, which is after or within %d seconds "
                                 "of key creation, and could contain "
                                 "transactions pertaining to the key. As a "
                                 "result, transactions and coins using this key "
                                 "may not appear in the wallet. This error "
                                 "could be caused by pruning or data corruption "
                                 "(see bitcoind log for details) and could be "
                                 "dealt with by downloading and rescanning the "
                                 "relevant blocks (see -reindex and -rescan "
                                 "options).",
                                 GetImportTimestamp(request, now),
                                 scannedTime - TIMESTAMP_WINDOW - 1,
                                 TIMESTAMP_WINDOW)));
                     response.push_back(std::move(result));
                 }
                 ++i;
             }
         }
     }
 
     return response;
 }
 
 // clang-format off
 static const ContextFreeRPCCommand commands[] = {
     //  category            name                        actor (function)          argNames
     //  ------------------- ------------------------    ----------------------    ----------
     { "wallet",             "abortrescan",              abortrescan,              {} },
     { "wallet",             "dumpprivkey",              dumpprivkey,              {"address"}  },
     { "wallet",             "dumpwallet",               dumpwallet,               {"filename"} },
     { "wallet",             "importmulti",              importmulti,              {"requests","options"} },
     { "wallet",             "importprivkey",            importprivkey,            {"privkey","label","rescan"} },
     { "wallet",             "importwallet",             importwallet,             {"filename"} },
     { "wallet",             "importaddress",            importaddress,            {"address","label","rescan","p2sh"} },
     { "wallet",             "importprunedfunds",        importprunedfunds,        {"rawtransaction","txoutproof"} },
     { "wallet",             "importpubkey",             importpubkey,             {"pubkey","label","rescan"} },
     { "wallet",             "removeprunedfunds",        removeprunedfunds,        {"txid"} },
 };
 // clang-format on
 
 void RegisterDumpRPCCommands(CRPCTable &t) {
     for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++) {
         t.appendCommand(commands[vcidx].name, &commands[vcidx]);
     }
 }
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index f1807bc638..7e67ac9d81 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -1,4981 +1,4978 @@
 // Copyright (c) 2010 Satoshi Nakamoto
 // Copyright (c) 2009-2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <amount.h>
 #include <chain.h>
 #include <chainparams.h> // for GetConsensus.
 #include <config.h>
 #include <consensus/validation.h>
 #include <core_io.h>
 #include <init.h>
 #include <interfaces/chain.h>
 #include <key_io.h>
 #include <net.h>
 #include <outputtype.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <rpc/mining.h>
 #include <rpc/rawtransaction.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
 #include <shutdown.h>
 #include <timedata.h>
 #include <util/moneystr.h>
 #include <util/system.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/wallet.h>
 #include <wallet/walletdb.h>
 #include <wallet/walletutil.h>
 
 #include <univalue.h>
 
 #include <event2/http.h>
 
 #include <functional>
 
 static const std::string WALLET_ENDPOINT_BASE = "/wallet/";
 
 static std::string urlDecode(const std::string &urlEncoded) {
     std::string res;
     if (!urlEncoded.empty()) {
         char *decoded = evhttp_uridecode(urlEncoded.c_str(), false, nullptr);
         if (decoded) {
             res = std::string(decoded);
             free(decoded);
         }
     }
     return res;
 }
 
 bool GetWalletNameFromJSONRPCRequest(const JSONRPCRequest &request,
                                      std::string &wallet_name) {
     if (request.URI.substr(0, WALLET_ENDPOINT_BASE.size()) ==
         WALLET_ENDPOINT_BASE) {
         // wallet endpoint was used
         wallet_name =
             urlDecode(request.URI.substr(WALLET_ENDPOINT_BASE.size()));
         return true;
     }
     return false;
 }
 
 std::shared_ptr<CWallet>
 GetWalletForJSONRPCRequest(const JSONRPCRequest &request) {
     std::string wallet_name;
     if (GetWalletNameFromJSONRPCRequest(request, wallet_name)) {
         std::shared_ptr<CWallet> pwallet = GetWallet(wallet_name);
         if (!pwallet) {
             throw JSONRPCError(
                 RPC_WALLET_NOT_FOUND,
                 "Requested wallet does not exist or is not loaded");
         }
         return pwallet;
     }
 
     std::vector<std::shared_ptr<CWallet>> wallets = GetWallets();
     return wallets.size() == 1 || (request.fHelp && wallets.size() > 0)
                ? wallets[0]
                : nullptr;
 }
 
 std::string HelpRequiringPassphrase(CWallet *const pwallet) {
     return pwallet && pwallet->IsCrypted()
                ? "\nRequires wallet passphrase to be set with walletpassphrase "
                  "call."
                : "";
 }
 
 bool EnsureWalletIsAvailable(CWallet *const pwallet, bool avoidException) {
     if (pwallet) {
         return true;
     }
     if (avoidException) {
         return false;
     }
     if (!HasWallets()) {
         throw JSONRPCError(RPC_METHOD_NOT_FOUND,
                            "Method not found (wallet method is disabled "
                            "because no wallet is loaded)");
     }
 
     throw JSONRPCError(RPC_WALLET_NOT_SPECIFIED,
                        "Wallet file not specified (must request wallet RPC "
                        "through /wallet/<filename> uri-path).");
 }
 
 void EnsureWalletIsUnlocked(CWallet *const pwallet) {
     if (pwallet->IsLocked()) {
         throw JSONRPCError(RPC_WALLET_UNLOCK_NEEDED,
                            "Error: Please enter the wallet passphrase with "
                            "walletpassphrase first.");
     }
 }
 
 static void WalletTxToJSON(interfaces::Chain &chain,
                            interfaces::Chain::Lock &locked_chain,
                            const CWalletTx &wtx, UniValue &entry) {
     int confirms = wtx.GetDepthInMainChain(locked_chain);
     entry.pushKV("confirmations", confirms);
     if (wtx.IsCoinBase()) {
         entry.pushKV("generated", true);
     }
     if (confirms > 0) {
         entry.pushKV("blockhash", wtx.hashBlock.GetHex());
         entry.pushKV("blockindex", wtx.nIndex);
-        entry.pushKV("blocktime",
-                     LookupBlockIndex(wtx.hashBlock)->GetBlockTime());
+        int64_t block_time;
+        bool found_block =
+            chain.findBlock(wtx.hashBlock, nullptr /* block */, &block_time);
+        assert(found_block);
+        entry.pushKV("blocktime", block_time);
     } else {
         entry.pushKV("trusted", wtx.IsTrusted(locked_chain));
     }
     uint256 hash = wtx.GetId();
     entry.pushKV("txid", hash.GetHex());
     UniValue conflicts(UniValue::VARR);
     for (const uint256 &conflict : wtx.GetConflicts()) {
         conflicts.push_back(conflict.GetHex());
     }
     entry.pushKV("walletconflicts", conflicts);
     entry.pushKV("time", wtx.GetTxTime());
     entry.pushKV("timereceived", (int64_t)wtx.nTimeReceived);
 
     for (const std::pair<const std::string, std::string> &item : wtx.mapValue) {
         entry.pushKV(item.first, item.second);
     }
 }
 
 static std::string LabelFromValue(const UniValue &value) {
     std::string label = value.get_str();
     if (label == "*") {
         throw JSONRPCError(RPC_WALLET_INVALID_LABEL_NAME, "Invalid label name");
     }
     return label;
 }
 
 static UniValue getnewaddress(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{
                 "getnewaddress",
                 "\nReturns a new Bitcoin address for receiving payments.\n"
                 "If 'label' is specified, it is added to the address book \n"
                 "so payments received with the address will be associated with "
                 "'label'.\n",
                 {
                     {"label", RPCArg::Type::STR, true},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"label\"          (string, optional) The label name for the "
             "address to be linked to. If not provided, the default label \"\" "
             "is used. It can also be set to the empty string \"\" to represent "
             "the default label. The label does not need to exist, it will be "
             "created if there is no label by the given name.\n"
             "\nResult:\n"
             "\"address\"    (string) The new bitcoin address\n"
             "\nExamples:\n" +
             HelpExampleRpc("getnewaddress", ""));
     }
 
     // Belt and suspenders check for disabled private keys
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: Private keys are disabled for this wallet");
     }
 
     LOCK(pwallet->cs_wallet);
 
     if (!pwallet->CanGetAddresses()) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: This wallet has no available keys");
     }
 
     // Parse the label first so we don't generate a key if there's an error
     std::string label;
     if (!request.params[0].isNull()) {
         label = LabelFromValue(request.params[0]);
     }
 
     OutputType output_type = pwallet->m_default_address_type;
     if (!request.params[1].isNull()) {
         if (!ParseOutputType(request.params[1].get_str(), output_type)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                strprintf("Unknown address type '%s'",
                                          request.params[1].get_str()));
         }
     }
 
     if (!pwallet->IsLocked()) {
         pwallet->TopUpKeyPool();
     }
 
     // Generate a new key that is added to wallet
     CPubKey newKey;
     if (!pwallet->GetKeyFromPool(newKey)) {
         throw JSONRPCError(
             RPC_WALLET_KEYPOOL_RAN_OUT,
             "Error: Keypool ran out, please call keypoolrefill first");
     }
     pwallet->LearnRelatedScripts(newKey, output_type);
     CTxDestination dest = GetDestinationForKey(newKey, output_type);
 
     pwallet->SetAddressBook(dest, label, "receive");
 
     return EncodeDestination(dest, config);
 }
 
 static UniValue getrawchangeaddress(const Config &config,
                                     const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             RPCHelpMan{
                 "getrawchangeaddress",
                 "\nReturns a new Bitcoin address, for receiving change.\n"
                 "This is for use with raw transactions, NOT normal use.\n",
                 {}}
                 .ToString() +
             "\nResult:\n"
             "\"address\"    (string) The address\n"
             "\nExamples:\n" +
             HelpExampleCli("getrawchangeaddress", "") +
             HelpExampleRpc("getrawchangeaddress", ""));
     }
 
     // Belt and suspenders check for disabled private keys
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: Private keys are disabled for this wallet");
     }
 
     LOCK(pwallet->cs_wallet);
 
     if (!pwallet->CanGetAddresses(true)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: This wallet has no available keys");
     }
 
     if (!pwallet->IsLocked()) {
         pwallet->TopUpKeyPool();
     }
 
     OutputType output_type =
         pwallet->m_default_change_type != OutputType::CHANGE_AUTO
             ? pwallet->m_default_change_type
             : pwallet->m_default_address_type;
     if (!request.params[0].isNull()) {
         if (!ParseOutputType(request.params[0].get_str(), output_type)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                strprintf("Unknown address type '%s'",
                                          request.params[0].get_str()));
         }
     }
 
     CReserveKey reservekey(pwallet);
     CPubKey vchPubKey;
     if (!reservekey.GetReservedKey(vchPubKey, true)) {
         throw JSONRPCError(
             RPC_WALLET_KEYPOOL_RAN_OUT,
             "Error: Keypool ran out, please call keypoolrefill first");
     }
 
     reservekey.KeepKey();
 
     pwallet->LearnRelatedScripts(vchPubKey, output_type);
     CTxDestination dest = GetDestinationForKey(vchPubKey, output_type);
 
     return EncodeDestination(dest, config);
 }
 
 static UniValue setlabel(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 2) {
         throw std::runtime_error(
             RPCHelpMan{"setlabel",
                        "\nSets the label associated with the given address.\n",
                        {
                            {"address", RPCArg::Type::STR, false},
                            {"label", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"address\"         (string, required) The bitcoin address to "
             "be associated with a label.\n"
             "2. \"label\"           (string, required) The label to assign to "
             "the address.\n"
             "\nExamples:\n" +
             HelpExampleCli("setlabel",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"tabby\"") +
             HelpExampleRpc(
                 "setlabel",
                 "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", \"tabby\""));
     }
     LOCK(pwallet->cs_wallet);
 
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address");
     }
 
     std::string old_label = pwallet->mapAddressBook[dest].name;
     std::string label = LabelFromValue(request.params[1]);
 
     if (IsMine(*pwallet, dest)) {
         pwallet->SetAddressBook(dest, label, "receive");
     } else {
         pwallet->SetAddressBook(dest, label, "send");
     }
 
     return NullUniValue;
 }
 
 static CTransactionRef SendMoney(interfaces::Chain::Lock &locked_chain,
                                  CWallet *const pwallet,
                                  const CTxDestination &address, Amount nValue,
                                  bool fSubtractFeeFromAmount,
                                  mapValue_t mapValue) {
     Amount curBalance = pwallet->GetBalance();
 
     // Check amount
     if (nValue <= Amount::zero()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid amount");
     }
 
     if (nValue > curBalance) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS, "Insufficient funds");
     }
 
     if (pwallet->GetBroadcastTransactions() && !g_connman) {
         throw JSONRPCError(
             RPC_CLIENT_P2P_DISABLED,
             "Error: Peer-to-peer functionality missing or disabled");
     }
 
     // Parse Bitcoin address
     CScript scriptPubKey = GetScriptForDestination(address);
 
     // Create and send the transaction
     CReserveKey reservekey(pwallet);
     Amount nFeeRequired;
     std::string strError;
     std::vector<CRecipient> vecSend;
     int nChangePosRet = -1;
     CRecipient recipient = {scriptPubKey, nValue, fSubtractFeeFromAmount};
     vecSend.push_back(recipient);
 
     CCoinControl coinControl;
     CTransactionRef tx;
     if (!pwallet->CreateTransaction(locked_chain, vecSend, tx, reservekey,
                                     nFeeRequired, nChangePosRet, strError,
                                     coinControl)) {
         if (!fSubtractFeeFromAmount && nValue + nFeeRequired > curBalance) {
             strError = strprintf("Error: This transaction requires a "
                                  "transaction fee of at least %s",
                                  FormatMoney(nFeeRequired));
         }
         throw JSONRPCError(RPC_WALLET_ERROR, strError);
     }
     CValidationState state;
     if (!pwallet->CommitTransaction(tx, std::move(mapValue), {} /* orderForm */,
                                     reservekey, g_connman.get(), state)) {
         strError =
             strprintf("Error: The transaction was rejected! Reason given: %s",
                       FormatStateMessage(state));
         throw JSONRPCError(RPC_WALLET_ERROR, strError);
     }
     return tx;
 }
 
 static UniValue sendtoaddress(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 5) {
         throw std::runtime_error(
             RPCHelpMan{"sendtoaddress",
                        "\nSend an amount to a given address.\n",
                        {
                            {"address", RPCArg::Type::STR, false},
                            {"amount", RPCArg::Type::AMOUNT, false},
                            {"comment", RPCArg::Type::STR, true},
                            {"comment_to", RPCArg::Type::STR, true},
                            {"subtractfeefromamount", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             HelpRequiringPassphrase(pwallet) +
             "\nArguments:\n"
             "1. \"address\"            (string, required) The bitcoin address "
             "to send to.\n"
             "2. \"amount\"             (numeric or string, required) The "
             "amount in " +
             CURRENCY_UNIT +
             " to send. eg 0.1\n"
             "3. \"comment\"            (string, optional) A comment used to "
             "store what the transaction is for. \n"
             "                             This is not part of the transaction, "
             "just kept in your wallet.\n"
             "4. \"comment_to\"         (string, optional) A comment to store "
             "the name of the person or organization \n"
             "                             to which you're sending the "
             "transaction. This is not part of the \n"
             "                             transaction, just kept in your "
             "wallet.\n"
             "5. subtractfeefromamount  (boolean, optional, default=false) The "
             "fee will be deducted from the amount being sent.\n"
             "                             The recipient will receive less "
             "bitcoins than you enter in the amount field.\n"
             "\nResult:\n"
             "\"txid\"                  (string) The transaction id.\n"
             "\nExamples:\n" +
             HelpExampleCli("sendtoaddress",
                            "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\" 0.1") +
             HelpExampleCli("sendtoaddress", "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvay"
                                             "dd\" 0.1 \"donation\" \"seans "
                                             "outpost\"") +
             HelpExampleCli(
                 "sendtoaddress",
                 "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\" 0.1 \"\" \"\" true") +
             HelpExampleRpc("sendtoaddress", "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvay"
                                             "dd\", 0.1, \"donation\", \"seans "
                                             "outpost\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address");
     }
 
     // Amount
     Amount nAmount = AmountFromValue(request.params[1]);
     if (nAmount <= Amount::zero()) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Invalid amount for send");
     }
 
     // Wallet comments
     mapValue_t mapValue;
     if (!request.params[2].isNull() && !request.params[2].get_str().empty()) {
         mapValue["comment"] = request.params[2].get_str();
     }
     if (!request.params[3].isNull() && !request.params[3].get_str().empty()) {
         mapValue["to"] = request.params[3].get_str();
     }
 
     bool fSubtractFeeFromAmount = false;
     if (!request.params[4].isNull()) {
         fSubtractFeeFromAmount = request.params[4].get_bool();
     }
 
     EnsureWalletIsUnlocked(pwallet);
 
     CTransactionRef tx = SendMoney(*locked_chain, pwallet, dest, nAmount,
                                    fSubtractFeeFromAmount, std::move(mapValue));
     return tx->GetId().GetHex();
 }
 
 static UniValue listaddressgroupings(const Config &config,
                                      const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             RPCHelpMan{"listaddressgroupings",
                        "\nLists groups of addresses which have had their "
                        "common ownership\n"
                        "made public by common use as inputs or as the "
                        "resulting change\n"
                        "in past transactions\n",
                        {}}
                 .ToString() +
             "\nResult:\n"
             "[\n"
             "  [\n"
             "    [\n"
             "      \"address\",            (string) The bitcoin address\n"
             "      amount,                 (numeric) The amount in " +
             CURRENCY_UNIT +
             "\n"
             "      \"label\"               (string, optional) The label\n"
             "    ]\n"
             "    ,...\n"
             "  ]\n"
             "  ,...\n"
             "]\n"
             "\nExamples:\n" +
             HelpExampleCli("listaddressgroupings", "") +
             HelpExampleRpc("listaddressgroupings", ""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     UniValue jsonGroupings(UniValue::VARR);
     std::map<CTxDestination, Amount> balances =
         pwallet->GetAddressBalances(*locked_chain);
     for (const std::set<CTxDestination> &grouping :
          pwallet->GetAddressGroupings()) {
         UniValue jsonGrouping(UniValue::VARR);
         for (const CTxDestination &address : grouping) {
             UniValue addressInfo(UniValue::VARR);
             addressInfo.push_back(EncodeDestination(address, config));
             addressInfo.push_back(ValueFromAmount(balances[address]));
 
             if (pwallet->mapAddressBook.find(address) !=
                 pwallet->mapAddressBook.end()) {
                 addressInfo.push_back(
                     pwallet->mapAddressBook.find(address)->second.name);
             }
             jsonGrouping.push_back(addressInfo);
         }
         jsonGroupings.push_back(jsonGrouping);
     }
 
     return jsonGroupings;
 }
 
 static UniValue signmessage(const Config &config,
                             const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 2) {
         throw std::runtime_error(
             RPCHelpMan{"signmessage",
                        "\nSign a message with the private key of an address",
                        {
                            {"address", RPCArg::Type::STR, false},
                            {"message", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             HelpRequiringPassphrase(pwallet) +
             "\n"
             "\nArguments:\n"
             "1. \"address\"         (string, required) The bitcoin address to "
             "use for the private key.\n"
             "2. \"message\"         (string, required) The message to create a "
             "signature of.\n"
             "\nResult:\n"
             "\"signature\"          (string) The signature of the message "
             "encoded in base 64\n"
             "\nExamples:\n"
             "\nUnlock the wallet for 30 seconds\n" +
             HelpExampleCli("walletpassphrase", "\"mypassphrase\" 30") +
             "\nCreate the signature\n" +
             HelpExampleCli(
                 "signmessage",
                 "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"my message\"") +
             "\nVerify the signature\n" +
             HelpExampleCli("verifymessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4"
                                             "XX\" \"signature\" \"my "
                                             "message\"") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc(
                 "signmessage",
                 "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", \"my message\""));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
     std::string strAddress = request.params[0].get_str();
     std::string strMessage = request.params[1].get_str();
 
     CTxDestination dest =
         DecodeDestination(strAddress, config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Invalid address");
     }
 
     const CKeyID *keyID = boost::get<CKeyID>(&dest);
     if (!keyID) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to key");
     }
 
     CKey key;
     if (!pwallet->GetKey(*keyID, key)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Private key not available");
     }
 
     CHashWriter ss(SER_GETHASH, 0);
     ss << strMessageMagic;
     ss << strMessage;
 
     std::vector<uint8_t> vchSig;
     if (!key.SignCompact(ss.GetHash(), vchSig)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Sign failed");
     }
 
     return EncodeBase64(vchSig.data(), vchSig.size());
 }
 
 static UniValue getreceivedbyaddress(const Config &config,
                                      const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{
                 "getreceivedbyaddress",
                 "\nReturns the total amount received by the given address in "
                 "transactions with at least minconf confirmations.\n",
                 {
                     {"address", RPCArg::Type::STR, false},
                     {"minconf", RPCArg::Type::NUM, true},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"address\"         (string, required) The bitcoin address for "
             "transactions.\n"
             "2. minconf             (numeric, optional, default=1) Only "
             "include transactions confirmed at least this many times.\n"
             "\nResult:\n"
             "amount   (numeric) The total amount in " +
             CURRENCY_UNIT +
             " received at this address.\n"
             "\nExamples:\n"
             "\nThe amount from transactions with at least 1 confirmation\n" +
             HelpExampleCli("getreceivedbyaddress",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\"") +
             "\nThe amount including unconfirmed transactions, zero "
             "confirmations\n" +
             HelpExampleCli("getreceivedbyaddress",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" 0") +
             "\nThe amount with at least 6 confirmations\n" +
             HelpExampleCli("getreceivedbyaddress",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" 6") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("getreceivedbyaddress",
                            "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", 6"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     // Temporary, for ContextualCheckTransactionForCurrentBlock below. Removed
     // in upcoming commit.
     LockAnnotation lock(::cs_main);
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     // Bitcoin address
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address");
     }
     CScript scriptPubKey = GetScriptForDestination(dest);
     if (!IsMine(*pwallet, scriptPubKey)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Address not found in wallet");
     }
 
     // Minimum confirmations
     int nMinDepth = 1;
     if (!request.params[1].isNull()) {
         nMinDepth = request.params[1].get_int();
     }
 
     // Tally
     Amount nAmount = Amount::zero();
     for (const std::pair<const TxId, CWalletTx> &pairWtx : pwallet->mapWallet) {
         const CWalletTx &wtx = pairWtx.second;
 
         CValidationState state;
         if (wtx.IsCoinBase() ||
             !ContextualCheckTransactionForCurrentBlock(
                 config.GetChainParams().GetConsensus(), *wtx.tx, state)) {
             continue;
         }
 
         for (const CTxOut &txout : wtx.tx->vout) {
             if (txout.scriptPubKey == scriptPubKey) {
                 if (wtx.GetDepthInMainChain(*locked_chain) >= nMinDepth) {
                     nAmount += txout.nValue;
                 }
             }
         }
     }
 
     return ValueFromAmount(nAmount);
 }
 
 static UniValue getreceivedbylabel(const Config &config,
                                    const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{
                 "getreceivedbylabel",
                 "\nReturns the total amount received by addresses with <label> "
                 "in transactions with at least [minconf] confirmations.\n",
                 {
                     {"label", RPCArg::Type::STR, false},
                     {"minconf", RPCArg::Type::NUM, true},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"label\"        (string, required) The selected label, may be "
             "the default label using \"\".\n"
             "2. minconf          (numeric, optional, default=1) Only include "
             "transactions confirmed at least this many times.\n"
             "\nResult:\n"
             "amount              (numeric) The total amount in " +
             CURRENCY_UNIT +
             " received for this label.\n"
             "\nExamples:\n"
             "\nAmount received by the default label with at least 1 "
             "confirmation\n" +
             HelpExampleCli("getreceivedbylabel", "\"\"") +
             "\nAmount received at the tabby label including unconfirmed "
             "amounts with zero confirmations\n" +
             HelpExampleCli("getreceivedbylabel", "\"tabby\" 0") +
             "\nThe amount with at least 6 confirmations\n" +
             HelpExampleCli("getreceivedbylabel", "\"tabby\" 6") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("getreceivedbylabel", "\"tabby\", 6"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     // Temporary, for ContextualCheckTransactionForCurrentBlock below. Removed
     // in upcoming commit.
     LockAnnotation lock(::cs_main);
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     // Minimum confirmations
     int nMinDepth = 1;
     if (!request.params[1].isNull()) {
         nMinDepth = request.params[1].get_int();
     }
 
     // Get the set of pub keys assigned to label
     std::string label = LabelFromValue(request.params[0]);
     std::set<CTxDestination> setAddress = pwallet->GetLabelAddresses(label);
 
     // Tally
     Amount nAmount = Amount::zero();
     for (const std::pair<const TxId, CWalletTx> &pairWtx : pwallet->mapWallet) {
         const CWalletTx &wtx = pairWtx.second;
         CValidationState state;
         if (wtx.IsCoinBase() ||
             !ContextualCheckTransactionForCurrentBlock(
                 config.GetChainParams().GetConsensus(), *wtx.tx, state)) {
             continue;
         }
 
         for (const CTxOut &txout : wtx.tx->vout) {
             CTxDestination address;
             if (ExtractDestination(txout.scriptPubKey, address) &&
                 IsMine(*pwallet, address) && setAddress.count(address)) {
                 if (wtx.GetDepthInMainChain(*locked_chain) >= nMinDepth) {
                     nAmount += txout.nValue;
                 }
             }
         }
     }
 
     return ValueFromAmount(nAmount);
 }
 
 static UniValue getbalance(const Config &config,
                            const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || (request.params.size() > 3)) {
         throw std::runtime_error(
             RPCHelpMan{"getbalance",
                        "\nReturns the total available balance.\n"
                        "The available balance is what the wallet considers "
                        "currently spendable, and is\n"
                        "thus affected by options which limit spendability such "
                        "as -spendzeroconfchange.\n",
                        {
                            {"dummy", RPCArg::Type::STR, true},
                            {"minconf", RPCArg::Type::NUM, true},
                            {"include_watchonly", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. (dummy)           (string, optional) Remains for "
             "backward compatibility. Must be excluded or set to "
             "\"*\".\n"
             "2. minconf           (numeric, optional, default=0) "
             "Only include transactions confirmed at least this many "
             "times.\n"
             "3. include_watchonly (bool, optional, default=false) Also include "
             "balance in watch-only addresses (see 'importaddress')\n"
             "\nResult:\n"
             "amount              (numeric) The total amount in " +
             CURRENCY_UNIT +
             " received for this wallet.\n"
             "\nExamples:\n"
             "\nThe total amount in the wallet with 1 or more confirmations\n" +
             HelpExampleCli("getbalance", "") +
             "\nThe total amount in the wallet at least 6 blocks confirmed\n" +
             HelpExampleCli("getbalance", "\"*\" 6") + "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("getbalance", "\"*\", 6"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     const UniValue &dummy_value = request.params[0];
     if (!dummy_value.isNull() && dummy_value.get_str() != "*") {
         throw JSONRPCError(
             RPC_METHOD_DEPRECATED,
             "dummy first argument must be excluded or set to \"*\".");
     }
 
     int min_depth = 0;
     if (!request.params[1].isNull()) {
         min_depth = request.params[1].get_int();
     }
 
     isminefilter filter = ISMINE_SPENDABLE;
     if (!request.params[2].isNull() && request.params[2].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     return ValueFromAmount(pwallet->GetBalance(filter, min_depth));
 }
 
 static UniValue getunconfirmedbalance(const Config &config,
                                       const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 0) {
         throw std::runtime_error(RPCHelpMan{
             "getunconfirmedbalance",
             "Returns the server's total unconfirmed balance\n",
             {}}.ToString());
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     return ValueFromAmount(pwallet->GetUnconfirmedBalance());
 }
 
 static UniValue sendmany(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 5) {
         throw std::runtime_error(
             RPCHelpMan{"sendmany",
                        "\nSend multiple times. Amounts are double-precision "
                        "floating point numbers.\n",
                        {
                            {"dummy", RPCArg::Type::STR, false, "\"\""},
                            {"amounts",
                             RPCArg::Type::OBJ,
                             {
                                 {"address", RPCArg::Type::AMOUNT, false},
                             },
                             false},
                            {"minconf", RPCArg::Type::NUM, true},
                            {"comment", RPCArg::Type::STR, true},
                            {"subtractfeefrom",
                             RPCArg::Type::ARR,
                             {
                                 {"address", RPCArg::Type::STR, true},
                             },
                             true},
                        }}
                 .ToString() +
             HelpRequiringPassphrase(pwallet) +
             "\n"
             "\nArguments:\n"
             "1. \"dummy\"               (string, required) Must be set to \"\" "
             "for backwards compatibility.\n"
             "2. \"amounts\"             (string, required) A json object with "
             "addresses and amounts\n"
             "    {\n"
             "      \"address\":amount   (numeric or string) The bitcoin "
             "address is the key, the numeric amount (can be string) in " +
             CURRENCY_UNIT +
             " is the value\n"
             "      ,...\n"
             "    }\n"
             "3. minconf                 (numeric, optional, default=1) Only "
             "use the balance confirmed at least this many times.\n"
             "4. \"comment\"             (string, optional) A comment\n"
             "5. subtractfeefrom         (array, optional) A json array with "
             "addresses.\n"
             "                           The fee will be equally deducted from "
             "the amount of each selected address.\n"
             "                           Those recipients will receive less "
             "bitcoins than you enter in their corresponding amount field.\n"
             "                           If no addresses are specified here, "
             "the sender pays the fee.\n"
             "    [\n"
             "      \"address\"          (string) Subtract fee from this "
             "address\n"
             "      ,...\n"
             "    ]\n"
             "\nResult:\n"
             "\"txid\"                   (string) The transaction id for the "
             "send. Only 1 transaction is created regardless of \n"
             "                                    the number of addresses.\n"
             "\nExamples:\n"
             "\nSend two amounts to two different addresses:\n" +
             HelpExampleCli("sendmany",
                            "\"\" "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}"
                            "\"") +
             "\nSend two amounts to two different addresses setting the "
             "confirmation and comment:\n" +
             HelpExampleCli("sendmany",
                            "\"\" "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}\" "
                            "6 \"testing\"") +
             "\nSend two amounts to two different addresses, subtract fee from "
             "amount:\n" +
             HelpExampleCli("sendmany",
                            "\"\" "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}\" "
                            "1 \"\" "
                            "\"[\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\","
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\"]\"") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("sendmany",
                            "\"\", "
                            "\"{\\\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\\\":0.01,"
                            "\\\"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz\\\":0.02}\","
                            " 6, \"testing\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     if (pwallet->GetBroadcastTransactions() && !g_connman) {
         throw JSONRPCError(
             RPC_CLIENT_P2P_DISABLED,
             "Error: Peer-to-peer functionality missing or disabled");
     }
 
     if (!request.params[0].isNull() && !request.params[0].get_str().empty()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Dummy value must be set to \"\"");
     }
     UniValue sendTo = request.params[1].get_obj();
     int nMinDepth = 1;
     if (!request.params[2].isNull()) {
         nMinDepth = request.params[2].get_int();
     }
 
     mapValue_t mapValue;
     if (!request.params[3].isNull() && !request.params[3].get_str().empty()) {
         mapValue["comment"] = request.params[3].get_str();
     }
 
     UniValue subtractFeeFromAmount(UniValue::VARR);
     if (!request.params[4].isNull()) {
         subtractFeeFromAmount = request.params[4].get_array();
     }
 
     std::set<CTxDestination> destinations;
     std::vector<CRecipient> vecSend;
 
     Amount totalAmount = Amount::zero();
     std::vector<std::string> keys = sendTo.getKeys();
     for (const std::string &name_ : keys) {
         CTxDestination dest = DecodeDestination(name_, config.GetChainParams());
         if (!IsValidDestination(dest)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                std::string("Invalid Bitcoin address: ") +
                                    name_);
         }
 
         if (destinations.count(dest)) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 std::string("Invalid parameter, duplicated address: ") + name_);
         }
         destinations.insert(dest);
 
         CScript scriptPubKey = GetScriptForDestination(dest);
         Amount nAmount = AmountFromValue(sendTo[name_]);
         if (nAmount <= Amount::zero()) {
             throw JSONRPCError(RPC_TYPE_ERROR, "Invalid amount for send");
         }
         totalAmount += nAmount;
 
         bool fSubtractFeeFromAmount = false;
         for (size_t idx = 0; idx < subtractFeeFromAmount.size(); idx++) {
             const UniValue &addr = subtractFeeFromAmount[idx];
             if (addr.get_str() == name_) {
                 fSubtractFeeFromAmount = true;
             }
         }
 
         CRecipient recipient = {scriptPubKey, nAmount, fSubtractFeeFromAmount};
         vecSend.push_back(recipient);
     }
 
     EnsureWalletIsUnlocked(pwallet);
 
     // Check funds
     if (totalAmount > pwallet->GetLegacyBalance(ISMINE_SPENDABLE, nMinDepth)) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS,
                            "Wallet has insufficient funds");
     }
 
     // Shuffle recipient list
     std::shuffle(vecSend.begin(), vecSend.end(), FastRandomContext());
 
     // Send
     CReserveKey keyChange(pwallet);
     Amount nFeeRequired = Amount::zero();
     int nChangePosRet = -1;
     std::string strFailReason;
     CTransactionRef tx;
     CCoinControl coinControl;
     bool fCreated = pwallet->CreateTransaction(
         *locked_chain, vecSend, tx, keyChange, nFeeRequired, nChangePosRet,
         strFailReason, coinControl);
     if (!fCreated) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS, strFailReason);
     }
     CValidationState state;
     if (!pwallet->CommitTransaction(tx, std::move(mapValue), {} /* orderForm */,
                                     keyChange, g_connman.get(), state)) {
         strFailReason = strprintf("Transaction commit failed:: %s",
                                   FormatStateMessage(state));
         throw JSONRPCError(RPC_WALLET_ERROR, strFailReason);
     }
 
     return tx->GetId().GetHex();
 }
 
 static UniValue addmultisigaddress(const Config &config,
                                    const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 3) {
         std::string msg =
             "addmultisigaddress nrequired [\"key\",...] ( \"label\" )\n"
             "\nAdd a nrequired-to-sign multisignature address to the wallet. "
             "Requires a new wallet backup.\n"
             "Each key is a Bitcoin address or hex-encoded public key.\n"
             "If 'label' is specified (DEPRECATED), assign address to that "
             "label.\n"
 
             "\nArguments:\n"
             "1. nrequired        (numeric, required) The number of required "
             "signatures out of the n keys or addresses.\n"
             "2. \"keys\"         (string, required) A json array of bitcoin "
             "addresses or hex-encoded public keys\n"
             "     [\n"
             "       \"address\"  (string) bitcoin address or hex-encoded "
             "public key\n"
             "       ...,\n"
             "     ]\n"
             "3. \"label\"                        (string, optional) A label to "
             "assign the addresses to.\n"
 
             "\nResult:\n"
             "{\n"
             "  \"address\":\"multisigaddress\",    (string) The value of the "
             "new multisig address.\n"
             "  \"redeemScript\":\"script\"         (string) The string value "
             "of the hex-encoded redemption script.\n"
             "}\n"
 
             "\nExamples:\n"
             "\nAdd a multisig address from 2 addresses\n" +
             HelpExampleCli("addmultisigaddress",
                            "2 "
                            "\"[\\\"16sSauSf5pF2UkUwvKGq4qjNRzBZYqgEL5\\\","
                            "\\\"171sgjn4YtPu27adkKGrdDwzRTxnRkBfKV\\\"]\"") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("addmultisigaddress",
                            "2, "
                            "\"[\\\"16sSauSf5pF2UkUwvKGq4qjNRzBZYqgEL5\\\","
                            "\\\"171sgjn4YtPu27adkKGrdDwzRTxnRkBfKV\\\"]\"");
         throw std::runtime_error(msg);
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     std::string label;
     if (!request.params[2].isNull()) {
         label = LabelFromValue(request.params[2]);
     }
 
     int required = request.params[0].get_int();
 
     // Get the public keys
     const UniValue &keys_or_addrs = request.params[1].get_array();
     std::vector<CPubKey> pubkeys;
     for (size_t i = 0; i < keys_or_addrs.size(); ++i) {
         if (IsHex(keys_or_addrs[i].get_str()) &&
             (keys_or_addrs[i].get_str().length() == 66 ||
              keys_or_addrs[i].get_str().length() == 130)) {
             pubkeys.push_back(HexToPubKey(keys_or_addrs[i].get_str()));
         } else {
             pubkeys.push_back(AddrToPubKey(config.GetChainParams(), pwallet,
                                            keys_or_addrs[i].get_str()));
         }
     }
 
     OutputType output_type = pwallet->m_default_address_type;
 
     // Construct using pay-to-script-hash:
     CScript inner = CreateMultisigRedeemscript(required, pubkeys);
     CTxDestination dest =
         AddAndGetDestinationForScript(*pwallet, inner, output_type);
     pwallet->SetAddressBook(dest, label, "send");
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("address", EncodeDestination(dest, config));
     result.pushKV("redeemScript", HexStr(inner.begin(), inner.end()));
     return result;
 }
 
 struct tallyitem {
     Amount nAmount{Amount::zero()};
     int nConf{std::numeric_limits<int>::max()};
     std::vector<uint256> txids;
     bool fIsWatchonly{false};
     tallyitem() {}
 };
 
 static UniValue
 ListReceived(const Config &config, interfaces::Chain::Lock &locked_chain,
              CWallet *const pwallet, const UniValue &params, bool by_label)
     EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet) {
     // Temporary, for ContextualCheckTransactionForCurrentBlock below. Removed
     // in upcoming commit.
     LockAnnotation lock(::cs_main);
 
     // Minimum confirmations
     int nMinDepth = 1;
     if (!params[0].isNull()) {
         nMinDepth = params[0].get_int();
     }
 
     // Whether to include empty labels
     bool fIncludeEmpty = false;
     if (!params[1].isNull()) {
         fIncludeEmpty = params[1].get_bool();
     }
 
     isminefilter filter = ISMINE_SPENDABLE;
     if (!params[2].isNull() && params[2].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     bool has_filtered_address = false;
     CTxDestination filtered_address = CNoDestination();
     if (!by_label && params.size() > 3) {
         if (!IsValidDestinationString(params[3].get_str(),
                                       config.GetChainParams())) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "address_filter parameter was invalid");
         }
         filtered_address =
             DecodeDestination(params[3].get_str(), config.GetChainParams());
         has_filtered_address = true;
     }
 
     // Tally
     std::map<CTxDestination, tallyitem> mapTally;
     for (const std::pair<const TxId, CWalletTx> &pairWtx : pwallet->mapWallet) {
         const CWalletTx &wtx = pairWtx.second;
 
         CValidationState state;
         if (wtx.IsCoinBase() ||
             !ContextualCheckTransactionForCurrentBlock(
                 config.GetChainParams().GetConsensus(), *wtx.tx, state)) {
             continue;
         }
 
         int nDepth = wtx.GetDepthInMainChain(locked_chain);
         if (nDepth < nMinDepth) {
             continue;
         }
 
         for (const CTxOut &txout : wtx.tx->vout) {
             CTxDestination address;
             if (!ExtractDestination(txout.scriptPubKey, address)) {
                 continue;
             }
 
             if (has_filtered_address && !(filtered_address == address)) {
                 continue;
             }
 
             isminefilter mine = IsMine(*pwallet, address);
             if (!(mine & filter)) {
                 continue;
             }
 
             tallyitem &item = mapTally[address];
             item.nAmount += txout.nValue;
             item.nConf = std::min(item.nConf, nDepth);
             item.txids.push_back(wtx.GetId());
             if (mine & ISMINE_WATCH_ONLY) {
                 item.fIsWatchonly = true;
             }
         }
     }
 
     // Reply
     UniValue ret(UniValue::VARR);
     std::map<std::string, tallyitem> label_tally;
 
     // Create mapAddressBook iterator
     // If we aren't filtering, go from begin() to end()
     auto start = pwallet->mapAddressBook.begin();
     auto end = pwallet->mapAddressBook.end();
     // If we are filtering, find() the applicable entry
     if (has_filtered_address) {
         start = pwallet->mapAddressBook.find(filtered_address);
         if (start != end) {
             end = std::next(start);
         }
     }
 
     for (auto item_it = start; item_it != end; ++item_it) {
         const CTxDestination &address = item_it->first;
         const std::string &label = item_it->second.name;
         std::map<CTxDestination, tallyitem>::iterator it =
             mapTally.find(address);
         if (it == mapTally.end() && !fIncludeEmpty) {
             continue;
         }
 
         Amount nAmount = Amount::zero();
         int nConf = std::numeric_limits<int>::max();
         bool fIsWatchonly = false;
         if (it != mapTally.end()) {
             nAmount = (*it).second.nAmount;
             nConf = (*it).second.nConf;
             fIsWatchonly = (*it).second.fIsWatchonly;
         }
 
         if (by_label) {
             tallyitem &_item = label_tally[label];
             _item.nAmount += nAmount;
             _item.nConf = std::min(_item.nConf, nConf);
             _item.fIsWatchonly = fIsWatchonly;
         } else {
             UniValue obj(UniValue::VOBJ);
             if (fIsWatchonly) {
                 obj.pushKV("involvesWatchonly", true);
             }
             obj.pushKV("address", EncodeDestination(address, config));
             obj.pushKV("amount", ValueFromAmount(nAmount));
             obj.pushKV("confirmations",
                        (nConf == std::numeric_limits<int>::max() ? 0 : nConf));
             obj.pushKV("label", label);
             UniValue transactions(UniValue::VARR);
             if (it != mapTally.end()) {
                 for (const uint256 &_item : (*it).second.txids) {
                     transactions.push_back(_item.GetHex());
                 }
             }
             obj.pushKV("txids", transactions);
             ret.push_back(obj);
         }
     }
 
     if (by_label) {
         for (const auto &entry : label_tally) {
             Amount nAmount = entry.second.nAmount;
             int nConf = entry.second.nConf;
             UniValue obj(UniValue::VOBJ);
             if (entry.second.fIsWatchonly) {
                 obj.pushKV("involvesWatchonly", true);
             }
             obj.pushKV("amount", ValueFromAmount(nAmount));
             obj.pushKV("confirmations",
                        (nConf == std::numeric_limits<int>::max() ? 0 : nConf));
             obj.pushKV("label", entry.first);
             ret.push_back(obj);
         }
     }
 
     return ret;
 }
 
 static UniValue listreceivedbyaddress(const Config &config,
                                       const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 4) {
         throw std::runtime_error(
             RPCHelpMan{"listreceivedbyaddress",
                        "\nList balances by receiving address.\n",
                        {
                            {"minconf", RPCArg::Type::NUM, true},
                            {"include_empty", RPCArg::Type::BOOL, true},
                            {"include_watchonly", RPCArg::Type::BOOL, true},
                            {"address_filter", RPCArg::Type::STR, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. minconf           (numeric, optional, default=1) The minimum "
             "number of confirmations before payments are included.\n"
             "2. include_empty     (bool, optional, default=false) Whether to "
             "include addresses that haven't received any payments.\n"
             "3. include_watchonly (bool, optional, default=false) Whether to "
             "include watch-only addresses (see 'importaddress').\n"
             "4. address_filter    (string, optional) If present, only return "
             "information on this address.\n"
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"involvesWatchonly\" : true,        (bool) Only returned if "
             "imported addresses were involved in transaction\n"
             "    \"address\" : \"receivingaddress\",  (string) The receiving "
             "address\n"
             "    \"amount\" : x.xxx,                  (numeric) The total "
             "amount in " +
             CURRENCY_UNIT +
             " received by the address\n"
             "    \"confirmations\" : n,               (numeric) The number of "
             "confirmations of the most recent transaction included\n"
             "    \"label\" : \"label\",               (string) The label of "
             "the receiving address. The default label is \"\".\n"
             "    \"txids\": [\n"
             "       \"txid\",                         (string) The ids of "
             "transactions received with the address \n"
             "       ...\n"
             "    ]\n"
             "  }\n"
             "  ,...\n"
             "]\n"
 
             "\nExamples:\n" +
             HelpExampleCli("listreceivedbyaddress", "") +
             HelpExampleCli("listreceivedbyaddress", "6 true") +
             HelpExampleRpc("listreceivedbyaddress", "6, true, true") +
             HelpExampleRpc(
                 "listreceivedbyaddress",
                 "6, true, true, \"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     return ListReceived(config, *locked_chain, pwallet, request.params, false);
 }
 
 static UniValue listreceivedbylabel(const Config &config,
                                     const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 3) {
         throw std::runtime_error(
             RPCHelpMan{"listreceivedbylabel",
                        "\nList received transactions by label.\n",
                        {
                            {"minconf", RPCArg::Type::NUM, true},
                            {"include_empty", RPCArg::Type::BOOL, true},
                            {"include_watchonly", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. minconf           (numeric, optional, default=1) The minimum "
             "number of confirmations before payments are included.\n"
             "2. include_empty     (bool, optional, default=false) Whether to "
             "include labels that haven't received any payments.\n"
             "3. include_watchonly (bool, optional, default=false) Whether to "
             "include watch-only addresses (see 'importaddress').\n"
 
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"involvesWatchonly\" : true,   (bool) Only returned if "
             "imported addresses were involved in transaction\n"
             "    \"amount\" : x.xxx,             (numeric) The total amount "
             "received by addresses with this label\n"
             "    \"confirmations\" : n,          (numeric) The number of "
             "confirmations of the most recent transaction included\n"
             "    \"label\" : \"label\"           (string) The label of the "
             "receiving address. The default label is \"\".\n"
             "  }\n"
             "  ,...\n"
             "]\n"
 
             "\nExamples:\n" +
             HelpExampleCli("listreceivedbylabel", "") +
             HelpExampleCli("listreceivedbylabel", "6 true") +
             HelpExampleRpc("listreceivedbylabel", "6, true, true"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     return ListReceived(config, *locked_chain, pwallet, request.params, true);
 }
 
 static void MaybePushAddress(UniValue &entry, const CTxDestination &dest) {
     if (IsValidDestination(dest)) {
         entry.pushKV("address", EncodeDestination(dest, GetConfig()));
     }
 }
 
 /**
  * List transactions based on the given criteria.
  *
  * @param  pwallet        The wallet.
  * @param  wtx            The wallet transaction.
  * @param  nMinDepth      The minimum confirmation depth.
  * @param  fLong          Whether to include the JSON version of the
  * transaction.
  * @param  ret            The UniValue into which the result is stored.
  * @param  filter_ismine  The "is mine" filter flags.
  * @param  filter_label   Optional label string to filter incoming transactions.
  */
 static void ListTransactions(interfaces::Chain::Lock &locked_chain,
                              CWallet *const pwallet, const CWalletTx &wtx,
                              int nMinDepth, bool fLong, UniValue &ret,
                              const isminefilter &filter_ismine,
                              const std::string *filter_label) {
     Amount nFee;
     std::list<COutputEntry> listReceived;
     std::list<COutputEntry> listSent;
 
     wtx.GetAmounts(listReceived, listSent, nFee, filter_ismine);
 
     bool involvesWatchonly = wtx.IsFromMe(ISMINE_WATCH_ONLY);
 
     // Sent
     if (!filter_label) {
         for (const COutputEntry &s : listSent) {
             UniValue entry(UniValue::VOBJ);
             if (involvesWatchonly ||
                 (::IsMine(*pwallet, s.destination) & ISMINE_WATCH_ONLY)) {
                 entry.pushKV("involvesWatchonly", true);
             }
             MaybePushAddress(entry, s.destination);
             entry.pushKV("category", "send");
             entry.pushKV("amount", ValueFromAmount(-s.amount));
             if (pwallet->mapAddressBook.count(s.destination)) {
                 entry.pushKV("label",
                              pwallet->mapAddressBook[s.destination].name);
             }
             entry.pushKV("vout", s.vout);
             entry.pushKV("fee", ValueFromAmount(-1 * nFee));
             if (fLong) {
                 WalletTxToJSON(pwallet->chain(), locked_chain, wtx, entry);
             }
             entry.pushKV("abandoned", wtx.isAbandoned());
             ret.push_back(entry);
         }
     }
 
     // Received
     if (listReceived.size() > 0 &&
         wtx.GetDepthInMainChain(locked_chain) >= nMinDepth) {
         for (const COutputEntry &r : listReceived) {
             std::string label;
             if (pwallet->mapAddressBook.count(r.destination)) {
                 label = pwallet->mapAddressBook[r.destination].name;
             }
             if (filter_label && label != *filter_label) {
                 continue;
             }
             UniValue entry(UniValue::VOBJ);
             if (involvesWatchonly ||
                 (::IsMine(*pwallet, r.destination) & ISMINE_WATCH_ONLY)) {
                 entry.pushKV("involvesWatchonly", true);
             }
             MaybePushAddress(entry, r.destination);
             if (wtx.IsCoinBase()) {
                 if (wtx.GetDepthInMainChain(locked_chain) < 1) {
                     entry.pushKV("category", "orphan");
                 } else if (wtx.IsImmatureCoinBase(locked_chain)) {
                     entry.pushKV("category", "immature");
                 } else {
                     entry.pushKV("category", "generate");
                 }
             } else {
                 entry.pushKV("category", "receive");
             }
             entry.pushKV("amount", ValueFromAmount(r.amount));
             if (pwallet->mapAddressBook.count(r.destination)) {
                 entry.pushKV("label", label);
             }
             entry.pushKV("vout", r.vout);
             if (fLong) {
                 WalletTxToJSON(pwallet->chain(), locked_chain, wtx, entry);
             }
             ret.push_back(entry);
         }
     }
 }
 
 UniValue listtransactions(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 4) {
         throw std::runtime_error(
             RPCHelpMan{
                 "listtransactions",
                 "\nIf a label name is provided, this will return only incoming "
                 "transactions paying to addresses with the specified label.\n"
                 "\nReturns up to 'count' most recent transactions skipping the "
                 "first 'from' transactions.\n",
                 {
                     {"label", RPCArg::Type::STR, true},
                     {"count", RPCArg::Type::NUM, true},
                     {"skip", RPCArg::Type::NUM, true},
                     {"include_watchonly", RPCArg::Type::BOOL, true},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"label\"    (string, optional) If set, should be a valid "
             "label name to return only incoming transactions with the "
             "specified label, or \"*\" to disable filtering and return all "
             "transactions.\n"
             "2. count          (numeric, optional, default=10) The number of "
             "transactions to return\n"
             "3. skip           (numeric, optional, default=0) The number of "
             "transactions to skip\n"
             "4. include_watchonly (bool, optional, default=false) Include "
             "transactions to watch-only addresses (see 'importaddress')\n"
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"address\":\"address\",    (string) The bitcoin address of "
             "the transaction.\n"
             "    \"category\":\"send|receive\", (string) The transaction "
             "category.\n"
             "    \"amount\": x.xxx,          (numeric) The amount in " +
             CURRENCY_UNIT +
             ". This is negative for the 'send' category, and is positive\n"
             "                                        for the 'receive' "
             "category,\n"
             "    \"label\": \"label\",       (string) A comment for the "
             "address/transaction, if any\n"
             "    \"vout\": n,                (numeric) the vout value\n"
             "    \"fee\": x.xxx,             (numeric) The amount of the fee "
             "in " +
             CURRENCY_UNIT +
             ". This is negative and only available for the \n"
             "                                         'send' category of "
             "transactions.\n"
             "    \"confirmations\": n,       (numeric) The number of "
             "confirmations for the transaction. Negative confirmations "
             "indicate the\n"
             "                                         transaction conflicts "
             "with the block chain\n"
             "    \"trusted\": xxx,           (bool) Whether we consider the "
             "outputs of this unconfirmed transaction safe to spend.\n"
             "    \"blockhash\": \"hashvalue\", (string) The block hash "
             "containing the transaction.\n"
             "    \"blockindex\": n,          (numeric) The index of the "
             "transaction in the block that includes it.\n"
             "    \"blocktime\": xxx,         (numeric) The block time in "
             "seconds since epoch (1 Jan 1970 GMT).\n"
             "    \"txid\": \"transactionid\", (string) The transaction id.\n"
             "    \"time\": xxx,              (numeric) The transaction time in "
             "seconds since epoch (midnight Jan 1 1970 GMT).\n"
             "    \"timereceived\": xxx,      (numeric) The time received in "
             "seconds since epoch (midnight Jan 1 1970 GMT).\n"
             "    \"comment\": \"...\",       (string) If a comment is "
             "associated with the transaction.\n"
             "    \"abandoned\": xxx          (bool) 'true' if the transaction "
             "has been abandoned (inputs are respendable). Only available for "
             "the \n"
             "                                         'send' category of "
             "transactions.\n"
             "  }\n"
             "]\n"
 
             "\nExamples:\n"
             "\nList the most recent 10 transactions in the systems\n" +
             HelpExampleCli("listtransactions", "") +
             "\nList transactions 100 to 120\n" +
             HelpExampleCli("listtransactions", "\"*\" 20 100") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("listtransactions", "\"*\", 20, 100"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     const std::string *filter_label = nullptr;
     if (!request.params[0].isNull() && request.params[0].get_str() != "*") {
         filter_label = &request.params[0].get_str();
         if (filter_label->empty()) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Label argument must be a valid label name or \"*\".");
         }
     }
     int nCount = 10;
     if (!request.params[1].isNull()) {
         nCount = request.params[1].get_int();
     }
 
     int nFrom = 0;
     if (!request.params[2].isNull()) {
         nFrom = request.params[2].get_int();
     }
 
     isminefilter filter = ISMINE_SPENDABLE;
     if (!request.params[3].isNull() && request.params[3].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     if (nCount < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative count");
     }
     if (nFrom < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative from");
     }
     UniValue ret(UniValue::VARR);
 
     const CWallet::TxItems &txOrdered = pwallet->wtxOrdered;
 
     // iterate backwards until we have nCount items to return:
     for (CWallet::TxItems::const_reverse_iterator it = txOrdered.rbegin();
          it != txOrdered.rend(); ++it) {
         CWalletTx *const pwtx = (*it).second;
         ListTransactions(*locked_chain, pwallet, *pwtx, 0, true, ret, filter,
                          filter_label);
         if ((int)ret.size() >= (nCount + nFrom)) {
             break;
         }
     }
 
     // ret is newest to oldest
 
     if (nFrom > (int)ret.size()) {
         nFrom = ret.size();
     }
     if ((nFrom + nCount) > (int)ret.size()) {
         nCount = ret.size() - nFrom;
     }
 
     std::vector<UniValue> arrTmp = ret.getValues();
 
     std::vector<UniValue>::iterator first = arrTmp.begin();
     std::advance(first, nFrom);
     std::vector<UniValue>::iterator last = arrTmp.begin();
     std::advance(last, nFrom + nCount);
 
     if (last != arrTmp.end()) {
         arrTmp.erase(last, arrTmp.end());
     }
     if (first != arrTmp.begin()) {
         arrTmp.erase(arrTmp.begin(), first);
     }
 
     // Return oldest to newest
     std::reverse(arrTmp.begin(), arrTmp.end());
 
     ret.clear();
     ret.setArray();
     ret.push_backV(arrTmp);
 
     return ret;
 }
 
 static UniValue listsinceblock(const Config &config,
                                const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 4) {
         throw std::runtime_error(
             RPCHelpMan{
                 "listsinceblock",
                 "\nGet all transactions in blocks since block [blockhash], or "
                 "all transactions if omitted.\n"
                 "If \"blockhash\" is no longer a part of the main chain, "
                 "transactions from the fork point onward are included.\n"
                 "Additionally, if include_removed is set, transactions "
                 "affecting the wallet which were removed are returned in the "
                 "\"removed\" array.\n",
                 {
                     {"blockhash", RPCArg::Type::STR, true},
                     {"target_confirmations", RPCArg::Type::NUM, true},
                     {"include_watchonly", RPCArg::Type::BOOL, true},
                     {"include_removed", RPCArg::Type::BOOL, true},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"blockhash\"            (string, optional) The block hash to "
             "list transactions since\n"
             "2. target_confirmations:    (numeric, optional, default=1) Return "
             "the nth block hash from the main chain. e.g. 1 would mean the "
             "best block hash. Note: this is not used as a filter, but only "
             "affects [lastblock] in the return value\n"
             "3. include_watchonly:       (bool, optional, default=false) "
             "Include transactions to watch-only addresses (see "
             "'importaddress')\n"
             "4. include_removed:         (bool, optional, default=true) Show "
             "transactions that were removed due to a reorg in the \"removed\" "
             "array\n"
             "                                                           (not "
             "guaranteed to work on pruned nodes)\n"
             "\nResult:\n"
             "{\n"
             "  \"transactions\": [\n"
             "    \"address\":\"address\",    (string) The bitcoin address of "
             "the transaction. Not present for move transactions (category = "
             "move).\n"
             "    \"category\":\"send|receive\",     (string) The transaction "
             "category. 'send' has negative amounts, 'receive' has positive "
             "amounts.\n"
             "    \"amount\": x.xxx,          (numeric) The amount in " +
             CURRENCY_UNIT +
             ". This is negative for the 'send' category, and for the 'move' "
             "category for moves \n"
             "                                          outbound. It is "
             "positive for the 'receive' category, and for the 'move' category "
             "for inbound funds.\n"
             "    \"vout\" : n,               (numeric) the vout value\n"
             "    \"fee\": x.xxx,             (numeric) The amount of the fee "
             "in " +
             CURRENCY_UNIT +
             ". This is negative and only available for the 'send' category of "
             "transactions.\n"
             "    \"confirmations\": n,       (numeric) The number of "
             "confirmations for the transaction. Available for 'send' and "
             "'receive' category of transactions.\n"
             "                                          When it's < 0, it means "
             "the transaction conflicted that many blocks ago.\n"
             "    \"blockhash\": \"hashvalue\",     (string) The block hash "
             "containing the transaction. Available for 'send' and 'receive' "
             "category of transactions.\n"
             "    \"blockindex\": n,          (numeric) The index of the "
             "transaction in the block that includes it. Available for 'send' "
             "and 'receive' category of transactions.\n"
             "    \"blocktime\": xxx,         (numeric) The block time in "
             "seconds since epoch (1 Jan 1970 GMT).\n"
             "    \"txid\": \"transactionid\",  (string) The transaction id. "
             "Available for 'send' and 'receive' category of transactions.\n"
             "    \"time\": xxx,              (numeric) The transaction time in "
             "seconds since epoch (Jan 1 1970 GMT).\n"
             "    \"timereceived\": xxx,      (numeric) The time received in "
             "seconds since epoch (Jan 1 1970 GMT). Available for 'send' and "
             "'receive' category of transactions.\n"
             "    \"abandoned\": xxx,         (bool) 'true' if the transaction "
             "has been abandoned (inputs are respendable). Only available for "
             "the 'send' category of transactions.\n"
             "    \"comment\": \"...\",       (string) If a comment is "
             "associated with the transaction.\n"
             "    \"label\" : \"label\"       (string) A comment for the "
             "address/transaction, if any\n"
             "    \"to\": \"...\",            (string) If a comment to is "
             "associated with the transaction.\n"
             "  ],\n"
             "  \"removed\": [\n"
             "    <structure is the same as \"transactions\" above, only "
             "present if include_removed=true>\n"
             "    Note: transactions that were re-added in the active chain "
             "will appear as-is in this array, and may thus have a positive "
             "confirmation count.\n"
             "  ],\n"
             "  \"lastblock\": \"lastblockhash\"     (string) The hash of the "
             "block (target_confirmations-1) from the best block on the main "
             "chain. This is typically used to feed back into listsinceblock "
             "the next time you call it. So you would generally use a "
             "target_confirmations of say 6, so you will be continually "
             "re-notified of transactions until they've reached 6 confirmations "
             "plus any new ones\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("listsinceblock", "") +
             HelpExampleCli("listsinceblock", "\"000000000000000bacf66f7497b7dc4"
                                              "5ef753ee9a7d38571037cdb1a57f663ad"
                                              "\" 6") +
             HelpExampleRpc("listsinceblock", "\"000000000000000bacf66f7497b7dc4"
                                              "5ef753ee9a7d38571037cdb1a57f663ad"
                                              "\", 6"));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
-    // Block index of the specified block or the common ancestor, if the block
+    // Height of the specified block or the common ancestor, if the block
     // provided was in a deactivated chain.
-    const CBlockIndex *pindex = nullptr;
-    // Block index of the specified block, even if it's in a deactivated chain.
-    const CBlockIndex *paltindex = nullptr;
+    Optional<int> height;
+    // Height of the specified block, even if it's in a deactivated chain.
+    Optional<int> altheight;
     int target_confirms = 1;
     isminefilter filter = ISMINE_SPENDABLE;
 
+    BlockHash blockId;
     if (!request.params[0].isNull() && !request.params[0].get_str().empty()) {
-        BlockHash blockId(ParseHashV(request.params[0], "blockhash"));
-
-        paltindex = pindex = LookupBlockIndex(blockId);
-        if (!pindex) {
+        blockId = BlockHash(ParseHashV(request.params[0], "blockhash"));
+        height = locked_chain->findFork(blockId, &altheight);
+        if (!height) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
-        if (::ChainActive()[pindex->nHeight] != pindex) {
-            // the block being asked for is a part of a deactivated chain;
-            // we don't want to depend on its perceived height in the block
-            // chain, we want to instead use the last common ancestor
-            pindex = ::ChainActive().FindFork(pindex);
-        }
     }
 
     if (!request.params[1].isNull()) {
         target_confirms = request.params[1].get_int();
 
         if (target_confirms < 1) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter");
         }
     }
 
     if (!request.params[2].isNull() && request.params[2].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     bool include_removed =
         (request.params[3].isNull() || request.params[3].get_bool());
 
-    int depth = pindex ? (1 + ::ChainActive().Height() - pindex->nHeight) : -1;
+    const Optional<int> tip_height = locked_chain->getHeight();
+    int depth = tip_height && height ? (1 + *tip_height - *height) : -1;
 
     UniValue transactions(UniValue::VARR);
 
     for (const std::pair<const TxId, CWalletTx> &pairWtx : pwallet->mapWallet) {
         CWalletTx tx = pairWtx.second;
 
         if (depth == -1 || tx.GetDepthInMainChain(*locked_chain) < depth) {
             ListTransactions(*locked_chain, pwallet, tx, 0, true, transactions,
                              filter, nullptr /* filter_label */);
         }
     }
 
-    const Consensus::Params &params = config.GetChainParams().GetConsensus();
-
     // when a reorg'd block is requested, we also list any relevant transactions
     // in the blocks of the chain that was detached
     UniValue removed(UniValue::VARR);
-    while (include_removed && paltindex && paltindex != pindex) {
+    while (include_removed && altheight && *altheight > *height) {
         CBlock block;
-        if (!ReadBlockFromDisk(block, paltindex, params)) {
+        if (!pwallet->chain().findBlock(blockId, &block) || block.IsNull()) {
             throw JSONRPCError(RPC_INTERNAL_ERROR,
                                "Can't read block from disk");
         }
         for (const CTransactionRef &tx : block.vtx) {
             auto it = pwallet->mapWallet.find(tx->GetId());
             if (it != pwallet->mapWallet.end()) {
                 // We want all transactions regardless of confirmation count to
                 // appear here, even negative confirmation ones, hence the big
                 // negative.
                 ListTransactions(*locked_chain, pwallet, it->second, -100000000,
                                  true, removed, filter,
                                  nullptr /* filter_label */);
             }
         }
-        paltindex = paltindex->pprev;
+        blockId = block.hashPrevBlock;
+        --*altheight;
     }
 
-    CBlockIndex *pblockLast =
-        ::ChainActive()[::ChainActive().Height() + 1 - target_confirms];
-    uint256 lastblock = pblockLast ? pblockLast->GetBlockHash() : uint256();
+    int last_height = tip_height ? *tip_height + 1 - target_confirms : -1;
+    BlockHash lastblock = last_height >= 0
+                              ? locked_chain->getBlockHash(last_height)
+                              : BlockHash();
 
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("transactions", transactions);
     if (include_removed) {
         ret.pushKV("removed", removed);
     }
     ret.pushKV("lastblock", lastblock.GetHex());
 
     return ret;
 }
 
 static UniValue gettransaction(const Config &config,
                                const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{"gettransaction",
                        "\nGet detailed information about in-wallet transaction "
                        "<txid>\n",
                        {
                            {"txid", RPCArg::Type::STR, false},
                            {"include_watchonly", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"txid\"                  (string, required) The transaction "
             "id\n"
             "2. \"include_watchonly\"     (bool, optional, default=false) "
             "Whether to include watch-only addresses in balance calculation "
             "and details[]\n"
             "\nResult:\n"
             "{\n"
             "  \"amount\" : x.xxx,        (numeric) The transaction amount "
             "in " +
             CURRENCY_UNIT +
             "\n"
             "  \"fee\": x.xxx,            (numeric) The amount of the fee in " +
             CURRENCY_UNIT +
             ". This is negative and only available for the \n"
             "                              'send' category of transactions.\n"
             "  \"confirmations\" : n,     (numeric) The number of "
             "confirmations\n"
             "  \"blockhash\" : \"hash\",  (string) The block hash\n"
             "  \"blockindex\" : xx,       (numeric) The index of the "
             "transaction in the block that includes it\n"
             "  \"blocktime\" : ttt,       (numeric) The time in seconds since "
             "epoch (1 Jan 1970 GMT)\n"
             "  \"txid\" : \"transactionid\",   (string) The transaction id.\n"
             "  \"time\" : ttt,            (numeric) The transaction time in "
             "seconds since epoch (1 Jan 1970 GMT)\n"
             "  \"timereceived\" : ttt,    (numeric) The time received in "
             "seconds since epoch (1 Jan 1970 GMT)\n"
             "  \"bip125-replaceable\": \"yes|no|unknown\",  (string) Whether "
             "this transaction could be replaced due to BIP125 "
             "(replace-by-fee);\n"
             "                                                   may be unknown "
             "for unconfirmed transactions not in the mempool\n"
             "  \"details\" : [\n"
             "    {\n"
             "      \"address\" : \"address\",          (string) The bitcoin "
             "address involved in the transaction\n"
             "      \"category\" : \"send|receive\",    (string) The category, "
             "either 'send' or 'receive'\n"
             "      \"amount\" : x.xxx,                 (numeric) The amount "
             "in " +
             CURRENCY_UNIT +
             "\n"
             "      \"label\" : \"label\",              "
             "(string) A comment for the address/transaction, "
             "if any\n"
             "      \"vout\" : n,                       "
             "(numeric) the vout value\n"
             "      \"fee\": x.xxx,                     "
             "(numeric) The amount of the fee in " +
             CURRENCY_UNIT +
             ". This is negative and only available for the \n"
             "                                           'send' category of "
             "transactions.\n"
             "      \"abandoned\": xxx                  (bool) 'true' if the "
             "transaction has been abandoned (inputs are respendable). Only "
             "available for the \n"
             "                                           'send' category of "
             "transactions.\n"
             "    }\n"
             "    ,...\n"
             "  ],\n"
             "  \"hex\" : \"data\"         (string) Raw data for transaction\n"
             "}\n"
 
             "\nExamples:\n" +
             HelpExampleCli("gettransaction", "\"1075db55d416d3ca199f55b6084e211"
                                              "5b9345e16c5cf302fc80e9d5fbf5d48d"
                                              "\"") +
             HelpExampleCli("gettransaction", "\"1075db55d416d3ca199f55b6084e211"
                                              "5b9345e16c5cf302fc80e9d5fbf5d48d"
                                              "\" true") +
             HelpExampleRpc("gettransaction", "\"1075db55d416d3ca199f55b6084e211"
                                              "5b9345e16c5cf302fc80e9d5fbf5d48d"
                                              "\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     TxId txid(ParseHashV(request.params[0], "txid"));
 
     isminefilter filter = ISMINE_SPENDABLE;
     if (!request.params[1].isNull() && request.params[1].get_bool()) {
         filter = filter | ISMINE_WATCH_ONLY;
     }
 
     UniValue entry(UniValue::VOBJ);
     auto it = pwallet->mapWallet.find(txid);
     if (it == pwallet->mapWallet.end()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid or non-wallet transaction id");
     }
     const CWalletTx &wtx = it->second;
 
     Amount nCredit = wtx.GetCredit(*locked_chain, filter);
     Amount nDebit = wtx.GetDebit(filter);
     Amount nNet = nCredit - nDebit;
     Amount nFee = (wtx.IsFromMe(filter) ? wtx.tx->GetValueOut() - nDebit
                                         : Amount::zero());
 
     entry.pushKV("amount", ValueFromAmount(nNet - nFee));
     if (wtx.IsFromMe(filter)) {
         entry.pushKV("fee", ValueFromAmount(nFee));
     }
 
     WalletTxToJSON(pwallet->chain(), *locked_chain, wtx, entry);
 
     UniValue details(UniValue::VARR);
     ListTransactions(*locked_chain, pwallet, wtx, 0, false, details, filter,
                      nullptr /* filter_label */);
     entry.pushKV("details", details);
 
     std::string strHex = EncodeHexTx(*wtx.tx, RPCSerializationFlags());
     entry.pushKV("hex", strHex);
 
     return entry;
 }
 
 static UniValue abandontransaction(const Config &config,
                                    const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             RPCHelpMan{"abandontransaction",
                        "\nMark in-wallet transaction <txid> as abandoned\n"
                        "This will mark this transaction and all its in-wallet "
                        "descendants as abandoned which will allow\n"
                        "for their inputs to be respent.  It can be used to "
                        "replace \"stuck\" or evicted transactions.\n"
                        "It only works on transactions which are not included "
                        "in a block and are not currently in the mempool.\n"
                        "It has no effect on transactions which are already "
                        "abandoned.\n",
                        {
                            {"txid", RPCArg::Type::STR_HEX, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"txid\"    (string, required) The transaction id\n"
             "\nResult:\n"
             "\nExamples:\n" +
             HelpExampleCli("abandontransaction", "\"1075db55d416d3ca199f55b6084"
                                                  "e2115b9345e16c5cf302fc80e9d5f"
                                                  "bf5d48d\"") +
             HelpExampleRpc("abandontransaction", "\"1075db55d416d3ca199f55b6084"
                                                  "e2115b9345e16c5cf302fc80e9d5f"
                                                  "bf5d48d\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     TxId txid(ParseHashV(request.params[0], "txid"));
 
     if (!pwallet->mapWallet.count(txid)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid or non-wallet transaction id");
     }
 
     if (!pwallet->AbandonTransaction(*locked_chain, txid)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Transaction not eligible for abandonment");
     }
 
     return NullUniValue;
 }
 
 static UniValue backupwallet(const Config &config,
                              const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             RPCHelpMan{"backupwallet",
                        "\nSafely copies current wallet file to destination, "
                        "which can be a directory or a path with filename.\n",
                        {
                            {"destination", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"destination\"   (string) The destination directory or file\n"
             "\nExamples:\n" +
             HelpExampleCli("backupwallet", "\"backup.dat\"") +
             HelpExampleRpc("backupwallet", "\"backup.dat\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     std::string strDest = request.params[0].get_str();
     if (!pwallet->BackupWallet(strDest)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Error: Wallet backup failed!");
     }
 
     return NullUniValue;
 }
 
 static UniValue keypoolrefill(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             RPCHelpMan{"keypoolrefill",
                        "\nFills the keypool.",
                        {
                            {"newsize", RPCArg::Type::NUM, true},
                        }}
                 .ToString() +
             HelpRequiringPassphrase(pwallet) +
             "\n"
             "\nArguments\n"
             "1. newsize     (numeric, optional, default=100) "
             "The new keypool size\n"
             "\nExamples:\n" +
             HelpExampleCli("keypoolrefill", "") +
             HelpExampleRpc("keypoolrefill", ""));
     }
 
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error: Private keys are disabled for this wallet");
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     // 0 is interpreted by TopUpKeyPool() as the default keypool size given by
     // -keypool
     unsigned int kpSize = 0;
     if (!request.params[0].isNull()) {
         if (request.params[0].get_int() < 0) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, expected valid size.");
         }
         kpSize = (unsigned int)request.params[0].get_int();
     }
 
     EnsureWalletIsUnlocked(pwallet);
     pwallet->TopUpKeyPool(kpSize);
 
     if (pwallet->GetKeyPoolSize() < kpSize) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Error refreshing keypool.");
     }
 
     return NullUniValue;
 }
 
 static void LockWallet(CWallet *pWallet) {
     LOCK(pWallet->cs_wallet);
     pWallet->nRelockTime = 0;
     pWallet->Lock();
 }
 
 static UniValue walletpassphrase(const Config &config,
                                  const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (pwallet->IsCrypted() && (request.fHelp || request.params.size() != 2)) {
         throw std::runtime_error(
             RPCHelpMan{"walletpassphrase",
                        "\nStores the wallet decryption key in memory for "
                        "'timeout' seconds.\n"
                        "This is needed prior to performing transactions "
                        "related to private keys such as sending bitcoins\n",
                        {
                            {"passphrase", RPCArg::Type::STR, false},
                            {"timeout", RPCArg::Type::NUM, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"passphrase\"     (string, required) The wallet passphrase\n"
             "2. timeout            (numeric, required) The time to keep the "
             "decryption key in seconds; capped at 100000000 (~3 years).\n"
             "\nNote:\n"
             "Issuing the walletpassphrase command while the wallet is already "
             "unlocked will set a new unlock\n"
             "time that overrides the old one.\n"
             "\nExamples:\n"
             "\nUnlock the wallet for 60 seconds\n" +
             HelpExampleCli("walletpassphrase", "\"my pass phrase\" 60") +
             "\nLock the wallet again (before 60 seconds)\n" +
             HelpExampleCli("walletlock", "") + "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("walletpassphrase", "\"my pass phrase\", 60"));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     if (request.fHelp) {
         return true;
     }
 
     if (!pwallet->IsCrypted()) {
         throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE,
                            "Error: running with an unencrypted wallet, but "
                            "walletpassphrase was called.");
     }
 
     // Note that the walletpassphrase is stored in request.params[0] which is
     // not mlock()ed
     SecureString strWalletPass;
     strWalletPass.reserve(100);
     // TODO: get rid of this .c_str() by implementing
     // SecureString::operator=(std::string)
     // Alternately, find a way to make request.params[0] mlock()'d to begin
     // with.
     strWalletPass = request.params[0].get_str().c_str();
 
     // Get the timeout
     int64_t nSleepTime = request.params[1].get_int64();
     // Timeout cannot be negative, otherwise it will relock immediately
     if (nSleepTime < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Timeout cannot be negative.");
     }
     // Clamp timeout
     // larger values trigger a macos/libevent bug?
     constexpr int64_t MAX_SLEEP_TIME = 100000000;
     if (nSleepTime > MAX_SLEEP_TIME) {
         nSleepTime = MAX_SLEEP_TIME;
     }
 
     if (strWalletPass.empty()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "passphrase can not be empty");
     }
 
     if (!pwallet->Unlock(strWalletPass)) {
         throw JSONRPCError(
             RPC_WALLET_PASSPHRASE_INCORRECT,
             "Error: The wallet passphrase entered was incorrect.");
     }
 
     pwallet->TopUpKeyPool();
 
     pwallet->nRelockTime = GetTime() + nSleepTime;
     RPCRunLater(strprintf("lockwallet(%s)", pwallet->GetName()),
                 std::bind(LockWallet, pwallet), nSleepTime);
 
     return NullUniValue;
 }
 
 static UniValue walletpassphrasechange(const Config &config,
                                        const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (pwallet->IsCrypted() && (request.fHelp || request.params.size() != 2)) {
         throw std::runtime_error(
             RPCHelpMan{"walletpassphrasechange",
                        "\nChanges the wallet passphrase from 'oldpassphrase' "
                        "to 'newpassphrase'.\n",
                        {
                            {"oldpassphrase", RPCArg::Type::STR, false},
                            {"newpassphrase", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"oldpassphrase\"      (string) The current passphrase\n"
             "2. \"newpassphrase\"      (string) The new passphrase\n"
             "\nExamples:\n" +
             HelpExampleCli("walletpassphrasechange",
                            "\"old one\" \"new one\"") +
             HelpExampleRpc("walletpassphrasechange",
                            "\"old one\", \"new one\""));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     if (request.fHelp) {
         return true;
     }
     if (!pwallet->IsCrypted()) {
         throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE,
                            "Error: running with an unencrypted wallet, but "
                            "walletpassphrasechange was called.");
     }
 
     // TODO: get rid of these .c_str() calls by implementing
     // SecureString::operator=(std::string)
     // Alternately, find a way to make request.params[0] mlock()'d to begin
     // with.
     SecureString strOldWalletPass;
     strOldWalletPass.reserve(100);
     strOldWalletPass = request.params[0].get_str().c_str();
 
     SecureString strNewWalletPass;
     strNewWalletPass.reserve(100);
     strNewWalletPass = request.params[1].get_str().c_str();
 
     if (strOldWalletPass.empty() || strNewWalletPass.empty()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "passphrase can not be empty");
     }
 
     if (!pwallet->ChangeWalletPassphrase(strOldWalletPass, strNewWalletPass)) {
         throw JSONRPCError(
             RPC_WALLET_PASSPHRASE_INCORRECT,
             "Error: The wallet passphrase entered was incorrect.");
     }
 
     return NullUniValue;
 }
 
 static UniValue walletlock(const Config &config,
                            const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (pwallet->IsCrypted() && (request.fHelp || request.params.size() != 0)) {
         throw std::runtime_error(
             RPCHelpMan{"walletlock",
                        "\nRemoves the wallet encryption key from memory, "
                        "locking the wallet.\n"
                        "After calling this method, you will need to call "
                        "walletpassphrase again\n"
                        "before being able to call any methods which require "
                        "the wallet to be unlocked.\n",
                        {}}
                 .ToString() +
             "\nExamples:\n"
             "\nSet the passphrase for 2 minutes to perform a transaction\n" +
             HelpExampleCli("walletpassphrase", "\"my pass phrase\" 120") +
             "\nPerform a send (requires passphrase set)\n" +
             HelpExampleCli("sendtoaddress",
                            "\"1M72Sfpbz1BPpXFHz9m3CdqATR44Jvaydd\" 1.0") +
             "\nClear the passphrase since we are done before 2 minutes is "
             "up\n" +
             HelpExampleCli("walletlock", "") + "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("walletlock", ""));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     if (request.fHelp) {
         return true;
     }
     if (!pwallet->IsCrypted()) {
         throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE,
                            "Error: running with an unencrypted wallet, but "
                            "walletlock was called.");
     }
 
     pwallet->Lock();
     pwallet->nRelockTime = 0;
 
     return NullUniValue;
 }
 
 static UniValue encryptwallet(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (!pwallet->IsCrypted() &&
         (request.fHelp || request.params.size() != 1)) {
         throw std::runtime_error(
             RPCHelpMan{"encryptwallet",
                        "\nEncrypts the wallet with 'passphrase'. This is for "
                        "first time encryption.\n"
                        "After this, any calls that interact with private keys "
                        "such as sending or signing \n"
                        "will require the passphrase to be set prior the making "
                        "these calls.\n"
                        "Use the walletpassphrase call for this, and then "
                        "walletlock call.\n"
                        "If the wallet is already encrypted, use the "
                        "walletpassphrasechange call.\n",
                        {
                            {"passphrase", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"passphrase\"    (string) The pass phrase to encrypt the "
             "wallet with. It must be at least 1 character, but should be "
             "long.\n"
             "\nExamples:\n"
             "\nEncrypt your wallet\n" +
             HelpExampleCli("encryptwallet", "\"my pass phrase\"") +
             "\nNow set the passphrase to use the wallet, such as for signing "
             "or sending bitcoin\n" +
             HelpExampleCli("walletpassphrase", "\"my pass phrase\"") +
             "\nNow we can do something like sign\n" +
             HelpExampleCli("signmessage", "\"address\" \"test message\"") +
             "\nNow lock the wallet again by removing the passphrase\n" +
             HelpExampleCli("walletlock", "") + "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("encryptwallet", "\"my pass phrase\""));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     if (request.fHelp) {
         return true;
     }
     if (pwallet->IsCrypted()) {
         throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE,
                            "Error: running with an encrypted wallet, but "
                            "encryptwallet was called.");
     }
 
     // TODO: get rid of this .c_str() by implementing
     // SecureString::operator=(std::string)
     // Alternately, find a way to make request.params[0] mlock()'d to begin
     // with.
     SecureString strWalletPass;
     strWalletPass.reserve(100);
     strWalletPass = request.params[0].get_str().c_str();
 
     if (strWalletPass.empty()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "passphrase can not be empty");
     }
 
     if (!pwallet->EncryptWallet(strWalletPass)) {
         throw JSONRPCError(RPC_WALLET_ENCRYPTION_FAILED,
                            "Error: Failed to encrypt the wallet.");
     }
 
     return "wallet encrypted; The keypool has been flushed and a new HD seed "
            "was generated (if you are using HD). You need to make a new "
            "backup.";
 }
 
 static UniValue lockunspent(const Config &config,
                             const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{
                 "lockunspent",
                 "\nUpdates list of temporarily unspendable outputs.\n"
                 "Temporarily lock (unlock=false) or unlock (unlock=true) "
                 "specified transaction outputs.\n"
                 "If no transaction outputs are specified when unlocking then "
                 "all current locked transaction outputs are unlocked.\n"
                 "A locked transaction output will not be chosen by automatic "
                 "coin selection, when spending bitcoins.\n"
                 "Locks are stored in memory only. Nodes start with zero locked "
                 "outputs, and the locked output list\n"
                 "is always cleared (by virtue of process exit) when a node "
                 "stops or fails.\n"
                 "Also see the listunspent call\n",
                 {
                     {"unlock", RPCArg::Type::BOOL, false},
                     {"transactions",
                      RPCArg::Type::ARR,
                      {
                          {"",
                           RPCArg::Type::OBJ,
                           {
                               {"txid", RPCArg::Type::STR_HEX, false},
                               {"vout", RPCArg::Type::NUM, false},
                           },
                           true},
                      },
                      true},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. unlock            (boolean, required) Whether to unlock (true) "
             "or lock (false) the specified transactions\n"
             "2. \"transactions\"  (string, optional) A json array of objects. "
             "Each object the txid (string) vout (numeric)\n"
             "     [           (json array of json objects)\n"
             "       {\n"
             "         \"txid\":\"id\",    (string) The transaction id\n"
             "         \"vout\": n         (numeric) The output number\n"
             "       }\n"
             "       ,...\n"
             "     ]\n"
 
             "\nResult:\n"
             "true|false    (boolean) Whether the command was successful or "
             "not\n"
 
             "\nExamples:\n"
             "\nList the unspent transactions\n" +
             HelpExampleCli("listunspent", "") +
             "\nLock an unspent transaction\n" +
             HelpExampleCli("lockunspent", "false "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\"") +
             "\nList the locked transactions\n" +
             HelpExampleCli("listlockunspent", "") +
             "\nUnlock the transaction again\n" +
             HelpExampleCli("lockunspent", "true "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\"") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("lockunspent", "false, "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     RPCTypeCheckArgument(request.params[0], UniValue::VBOOL);
 
     bool fUnlock = request.params[0].get_bool();
 
     if (request.params[1].isNull()) {
         if (fUnlock) {
             pwallet->UnlockAllCoins();
         }
         return true;
     }
 
     RPCTypeCheckArgument(request.params[1], UniValue::VARR);
 
     const UniValue &output_params = request.params[1];
 
     // Create and validate the COutPoints first.
 
     std::vector<COutPoint> outputs;
     outputs.reserve(output_params.size());
 
     for (size_t idx = 0; idx < output_params.size(); idx++) {
         const UniValue &o = output_params[idx].get_obj();
 
         RPCTypeCheckObj(o, {
                                {"txid", UniValueType(UniValue::VSTR)},
                                {"vout", UniValueType(UniValue::VNUM)},
                            });
 
         const int nOutput = find_value(o, "vout").get_int();
         if (nOutput < 0) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, vout must be positive");
         }
 
         const TxId txid(ParseHashO(o, "txid"));
         const auto it = pwallet->mapWallet.find(txid);
         if (it == pwallet->mapWallet.end()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, unknown transaction");
         }
 
         const COutPoint output(txid, nOutput);
         const CWalletTx &trans = it->second;
         if (output.GetN() >= trans.tx->vout.size()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, vout index out of bounds");
         }
 
         if (pwallet->IsSpent(*locked_chain, output)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, expected unspent output");
         }
 
         const bool is_locked = pwallet->IsLockedCoin(output);
         if (fUnlock && !is_locked) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, expected locked output");
         }
 
         if (!fUnlock && is_locked) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Invalid parameter, output already locked");
         }
 
         outputs.push_back(output);
     }
 
     // Atomically set (un)locked status for the outputs.
     for (const COutPoint &output : outputs) {
         if (fUnlock) {
             pwallet->UnlockCoin(output);
         } else {
             pwallet->LockCoin(output);
         }
     }
 
     return true;
 }
 
 static UniValue listlockunspent(const Config &config,
                                 const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 0) {
         throw std::runtime_error(
             RPCHelpMan{"listlockunspent",
                        "\nReturns list of temporarily unspendable outputs.\n"
                        "See the lockunspent call to lock and unlock "
                        "transactions for spending.\n",
                        {}}
                 .ToString() +
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"txid\" : \"transactionid\",     (string) The transaction id "
             "locked\n"
             "    \"vout\" : n                      (numeric) The vout value\n"
             "  }\n"
             "  ,...\n"
             "]\n"
             "\nExamples:\n"
             "\nList the unspent transactions\n" +
             HelpExampleCli("listunspent", "") +
             "\nLock an unspent transaction\n" +
             HelpExampleCli("lockunspent", "false "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\"") +
             "\nList the locked transactions\n" +
             HelpExampleCli("listlockunspent", "") +
             "\nUnlock the transaction again\n" +
             HelpExampleCli("lockunspent", "true "
                                           "\"[{\\\"txid\\\":"
                                           "\\\"a08e6907dbbd3d809776dbfc5d82e371"
                                           "b764ed838b5655e72f463568df1aadf0\\\""
                                           ",\\\"vout\\\":1}]\"") +
             "\nAs a JSON-RPC call\n" + HelpExampleRpc("listlockunspent", ""));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     std::vector<COutPoint> vOutpts;
     pwallet->ListLockedCoins(vOutpts);
 
     UniValue ret(UniValue::VARR);
 
     for (const COutPoint &output : vOutpts) {
         UniValue o(UniValue::VOBJ);
 
         o.pushKV("txid", output.GetTxId().GetHex());
         o.pushKV("vout", int(output.GetN()));
         ret.push_back(o);
     }
 
     return ret;
 }
 
 static UniValue settxfee(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 1) {
         throw std::runtime_error(
             RPCHelpMan{
                 "settxfee",
                 "\nSet the transaction fee per kB for this wallet. Overrides "
                 "the global -paytxfee command line parameter.\n",
                 {
                     {"amount", RPCArg::Type::AMOUNT, false},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. amount         (numeric or string, required) The transaction "
             "fee in " +
             CURRENCY_UNIT +
             "/kB\n"
             "\nResult\n"
             "true|false        (boolean) Returns true if successful\n"
             "\nExamples:\n" +
             HelpExampleCli("settxfee", "0.00001") +
             HelpExampleRpc("settxfee", "0.00001"));
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     Amount nAmount = AmountFromValue(request.params[0]);
     CFeeRate tx_fee_rate(nAmount, 1000);
     if (tx_fee_rate == CFeeRate()) {
         // automatic selection
     } else if (tx_fee_rate < ::minRelayTxFee) {
         throw JSONRPCError(
             RPC_INVALID_PARAMETER,
             strprintf("txfee cannot be less than min relay tx fee (%s)",
                       ::minRelayTxFee.ToString()));
     } else if (tx_fee_rate < pwallet->m_min_fee) {
         throw JSONRPCError(
             RPC_INVALID_PARAMETER,
             strprintf("txfee cannot be less than wallet min fee (%s)",
                       pwallet->m_min_fee.ToString()));
     }
 
     pwallet->m_pay_tx_fee = tx_fee_rate;
     return true;
 }
 
 static UniValue getwalletinfo(const Config &config,
                               const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             RPCHelpMan{
                 "getwalletinfo",
                 "Returns an object containing various wallet state info.\n",
                 {}}
                 .ToString() +
             "\nResult:\n"
             "{\n"
             "  \"walletname\": xxxxx,             (string) the wallet name\n"
             "  \"walletversion\": xxxxx,          (numeric) the wallet "
             "version\n"
             "  \"balance\": xxxxxxx,              (numeric) the total "
             "confirmed balance of the wallet in " +
             CURRENCY_UNIT +
             "\n"
             "  \"unconfirmed_balance\": xxx,      (numeric) "
             "the total unconfirmed balance of the wallet in " +
             CURRENCY_UNIT +
             "\n"
             "  \"immature_balance\": xxxxxx,      (numeric) "
             "the total immature balance of the wallet in " +
             CURRENCY_UNIT +
             "\n"
             "  \"txcount\": xxxxxxx,              (numeric) the total number "
             "of transactions in the wallet\n"
             "  \"keypoololdest\": xxxxxx,         (numeric) the timestamp "
             "(seconds since Unix epoch) of the oldest pre-generated key in the "
             "key pool\n"
             "  \"keypoolsize\": xxxx,             (numeric) how many new keys "
             "are pre-generated (only counts external keys)\n"
             "  \"keypoolsize_hd_internal\": xxxx, (numeric) how many new keys "
             "are pre-generated for internal use (used for change outputs, only "
             "appears if the wallet is using this feature, otherwise external "
             "keys are used)\n"
             "  \"unlocked_until\": ttt,           (numeric) the timestamp in "
             "seconds since epoch (midnight Jan 1 1970 GMT) that the wallet is "
             "unlocked for transfers, or 0 if the wallet is locked\n"
             "  \"paytxfee\": x.xxxx,              (numeric) the transaction "
             "fee configuration, set in " +
             CURRENCY_UNIT +
             "/kB\n"
             "  \"hdseedid\": \"<hash160>\"          (string, optional) the "
             "Hash160 of the HD seed (only present when HD is enabled)\n"
             "  \"hdmasterkeyid\": \"<hash160>\"     (string, optional) alias "
             "for hdseedid retained for backwards-compatibility. Will be "
             "removed in V0.21.\n"
             "  \"private_keys_enabled\": true|false (boolean) false if "
             "privatekeys are disabled for this wallet (enforced watch-only "
             "wallet)\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getwalletinfo", "") +
             HelpExampleRpc("getwalletinfo", ""));
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     UniValue obj(UniValue::VOBJ);
 
     size_t kpExternalSize = pwallet->KeypoolCountExternalKeys();
     obj.pushKV("walletname", pwallet->GetName());
     obj.pushKV("walletversion", pwallet->GetVersion());
     obj.pushKV("balance", ValueFromAmount(pwallet->GetBalance()));
     obj.pushKV("unconfirmed_balance",
                ValueFromAmount(pwallet->GetUnconfirmedBalance()));
     obj.pushKV("immature_balance",
                ValueFromAmount(pwallet->GetImmatureBalance()));
     obj.pushKV("txcount", (int)pwallet->mapWallet.size());
     obj.pushKV("keypoololdest", pwallet->GetOldestKeyPoolTime());
     obj.pushKV("keypoolsize", (int64_t)kpExternalSize);
     CKeyID seed_id = pwallet->GetHDChain().seed_id;
     if (!seed_id.IsNull() && pwallet->CanSupportFeature(FEATURE_HD_SPLIT)) {
         obj.pushKV("keypoolsize_hd_internal",
                    int64_t(pwallet->GetKeyPoolSize() - kpExternalSize));
     }
     if (pwallet->IsCrypted()) {
         obj.pushKV("unlocked_until", pwallet->nRelockTime);
     }
     obj.pushKV("paytxfee", ValueFromAmount(pwallet->m_pay_tx_fee.GetFeePerK()));
     if (!seed_id.IsNull()) {
         obj.pushKV("hdseedid", seed_id.GetHex());
         obj.pushKV("hdmasterkeyid", seed_id.GetHex());
     }
     obj.pushKV("private_keys_enabled",
                !pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
     return obj;
 }
 
 static UniValue listwalletdir(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             RPCHelpMan{"listwalletdir",
                        "Returns a list of wallets in the wallet directory.\n",
                        {}}
                 .ToString() +
             "{\n"
             "  \"wallets\" : [                (json array of objects)\n"
             "    {\n"
             "      \"name\" : \"name\"          (string) The wallet name\n"
             "    }\n"
             "    ,...\n"
             "  ]\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("listwalletdir", "") +
             HelpExampleRpc("listwalletdir", ""));
     }
 
     UniValue wallets(UniValue::VARR);
     for (const auto &path : ListWalletDir()) {
         UniValue wallet(UniValue::VOBJ);
         wallet.pushKV("name", path.string());
         wallets.push_back(wallet);
     }
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("wallets", wallets);
     return result;
 }
 
 static UniValue listwallets(const Config &config,
                             const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             RPCHelpMan{
                 "listwallets",
                 "Returns a list of currently loaded wallets.\n"
                 "For full information on the wallet, use \"getwalletinfo\"\n",
                 {}}
                 .ToString() +
             "\nResult:\n"
             "[                         (json array of strings)\n"
             "  \"walletname\"            (string) the wallet name\n"
             "   ...\n"
             "]\n"
             "\nExamples:\n" +
             HelpExampleCli("listwallets", "") +
             HelpExampleRpc("listwallets", ""));
     }
 
     UniValue obj(UniValue::VARR);
 
     for (const std::shared_ptr<CWallet> &wallet : GetWallets()) {
         if (!EnsureWalletIsAvailable(wallet.get(), request.fHelp)) {
             return NullUniValue;
         }
 
         LOCK(wallet->cs_wallet);
 
         obj.push_back(wallet->GetName());
     }
 
     return obj;
 }
 
 static UniValue loadwallet(const Config &config,
                            const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             RPCHelpMan{"loadwallet",
                        "\nLoads a wallet from a wallet file or directory."
                        "\nNote that all wallet command-line options used when "
                        "starting bitcoind will be"
                        "\napplied to the new wallet (eg -zapwallettxes, "
                        "upgradewallet, rescan, etc).\n",
                        {
                            {"filename", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"filename\"    (string, required) The wallet directory or "
             ".dat file.\n"
             "\nResult:\n"
             "{\n"
             "  \"name\" :    <wallet_name>,        (string) The wallet name if "
             "loaded successfully.\n"
             "  \"warning\" : <warning>,            (string) Warning message if "
             "wallet was not loaded cleanly.\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("loadwallet", "\"test.dat\"") +
             HelpExampleRpc("loadwallet", "\"test.dat\""));
     }
 
     const CChainParams &chainParams = config.GetChainParams();
 
     WalletLocation location(request.params[0].get_str());
     std::string error;
 
     if (!location.Exists()) {
         throw JSONRPCError(RPC_WALLET_NOT_FOUND,
                            "Wallet " + location.GetName() + " not found.");
     } else if (fs::is_directory(location.GetPath())) {
         // The given filename is a directory. Check that there's a wallet.dat
         // file.
         fs::path wallet_dat_file = location.GetPath() / "wallet.dat";
         if (fs::symlink_status(wallet_dat_file).type() == fs::file_not_found) {
             throw JSONRPCError(RPC_WALLET_NOT_FOUND,
                                "Directory " + location.GetName() +
                                    " does not contain a wallet.dat file.");
         }
     }
 
     std::string warning;
     if (!CWallet::Verify(chainParams, *g_rpc_interfaces->chain, location, false,
                          error, warning)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Wallet file verification failed: " + error);
     }
 
     std::shared_ptr<CWallet> const wallet = CWallet::CreateWalletFromFile(
         chainParams, *g_rpc_interfaces->chain, location);
     if (!wallet) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Wallet loading failed.");
     }
     AddWallet(wallet);
 
     wallet->postInitProcess();
 
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("name", wallet->GetName());
     obj.pushKV("warning", warning);
 
     return obj;
 }
 
 static UniValue createwallet(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 3) {
         throw std::runtime_error(
             RPCHelpMan{"createwallet",
                        "\nCreates and loads a new wallet.\n",
                        {
                            {"wallet_name", RPCArg::Type::STR, false},
                            {"disable_private_keys", RPCArg::Type::BOOL, true},
                            {"blank", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"wallet_name\"    (string, required) The name for the new "
             "wallet. If this is a path, the wallet will be created at the path "
             "location.\n"
             "2. disable_private_keys   (boolean, optional, default: false) "
             "Disable the possibility of private keys (only watchonlys are "
             "possible in this mode).\n"
             "3. blank   (boolean, optional, default: false) Create a blank "
             "wallet. A blank wallet has no keys or HD seed. One can be set "
             "using sethdseed.\n"
             "\nResult:\n"
             "{\n"
             "  \"name\" :    <wallet_name>,        (string) The wallet name if "
             "created successfully. If the wallet was created using a full "
             "path, the wallet_name will be the full path.\n"
             "  \"warning\" : <warning>,            (string) Warning message if "
             "wallet was not loaded cleanly.\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("createwallet", "\"testwallet\"") +
             HelpExampleRpc("createwallet", "\"testwallet\""));
     }
 
     const CChainParams &chainParams = config.GetChainParams();
 
     std::string error;
     std::string warning;
 
     uint64_t flags = 0;
     if (!request.params[1].isNull() && request.params[1].get_bool()) {
         flags |= WALLET_FLAG_DISABLE_PRIVATE_KEYS;
     }
 
     if (!request.params[2].isNull() && request.params[2].get_bool()) {
         flags |= WALLET_FLAG_BLANK_WALLET;
     }
 
     WalletLocation location(request.params[0].get_str());
     if (location.Exists()) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Wallet " + location.GetName() + " already exists.");
     }
 
     // Wallet::Verify will check if we're trying to create a wallet with a
     // duplicate name.
     if (!CWallet::Verify(chainParams, *g_rpc_interfaces->chain, location, false,
                          error, warning)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Wallet file verification failed: " + error);
     }
 
     std::shared_ptr<CWallet> const wallet = CWallet::CreateWalletFromFile(
         chainParams, *g_rpc_interfaces->chain, location, flags);
     if (!wallet) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Wallet creation failed.");
     }
     AddWallet(wallet);
 
     wallet->postInitProcess();
 
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("name", wallet->GetName());
     obj.pushKV("warning", warning);
 
     return obj;
 }
 
 static UniValue unloadwallet(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             RPCHelpMan{
                 "unloadwallet",
                 "Unloads the wallet referenced by the request endpoint "
                 "otherwise unloads the wallet specified in the argument.\n"
                 "Specifying the wallet name on a wallet endpoint is invalid.",
                 {
                     {"wallet_name", RPCArg::Type::STR, true},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"wallet_name\"    (string, optional) The name of the wallet "
             "to unload.\n"
             "\nExamples:\n" +
             HelpExampleCli("unloadwallet", "wallet_name") +
             HelpExampleRpc("unloadwallet", "wallet_name"));
     }
 
     std::string wallet_name;
     if (GetWalletNameFromJSONRPCRequest(request, wallet_name)) {
         if (!request.params[0].isNull()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Cannot unload the requested wallet");
         }
     } else {
         wallet_name = request.params[0].get_str();
     }
 
     std::shared_ptr<CWallet> wallet = GetWallet(wallet_name);
     if (!wallet) {
         throw JSONRPCError(RPC_WALLET_NOT_FOUND,
                            "Requested wallet does not exist or is not loaded");
     }
 
     // Release the "main" shared pointer and prevent further notifications.
     // Note that any attempt to load the same wallet would fail until the wallet
     // is destroyed (see CheckUniqueFileid).
     if (!RemoveWallet(wallet)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Requested wallet already unloaded");
     }
 
     UnloadWallet(std::move(wallet));
 
     return NullUniValue;
 }
 
 static UniValue resendwallettransactions(const Config &config,
                                          const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             RPCHelpMan{"resendwallettransactions",
                        "Immediately re-broadcast unconfirmed wallet "
                        "transactions to all peers.\n"
                        "Intended only for testing; the wallet code "
                        "periodically re-broadcasts\n",
                        {}}
                 .ToString() +
             "automatically.\n"
             "Returns an RPC error if -walletbroadcast is set to false.\n"
             "Returns array of transaction ids that were re-broadcast.\n");
     }
 
     if (!g_connman) {
         throw JSONRPCError(
             RPC_CLIENT_P2P_DISABLED,
             "Error: Peer-to-peer functionality missing or disabled");
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     if (!pwallet->GetBroadcastTransactions()) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Error: Wallet transaction "
                                              "broadcasting is disabled with "
                                              "-walletbroadcast");
     }
 
     std::vector<uint256> txids = pwallet->ResendWalletTransactionsBefore(
         *locked_chain, GetTime(), g_connman.get());
     UniValue result(UniValue::VARR);
     for (const uint256 &txid : txids) {
         result.push_back(txid.ToString());
     }
 
     return result;
 }
 
 static UniValue listunspent(const Config &config,
                             const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 5) {
         throw std::runtime_error(
             RPCHelpMan{
                 "listunspent",
                 "\nReturns array of unspent transaction outputs\n"
                 "with between minconf and maxconf (inclusive) confirmations.\n"
                 "Optionally filter to only include txouts paid to specified "
                 "addresses.\n",
                 {
                     {"minconf", RPCArg::Type::NUM, true},
                     {"maxconf", RPCArg::Type::NUM, true},
                     {"addresses",
                      RPCArg::Type::ARR,
                      {
                          {"address", RPCArg::Type::STR, true},
                      },
                      true},
                     {"include_unsafe", RPCArg::Type::BOOL, true},
                     {"query_options",
                      RPCArg::Type::OBJ,
                      {
                          {"minimumAmount", RPCArg::Type::AMOUNT, true},
                          {"maximumAmount", RPCArg::Type::AMOUNT, true},
                          {"maximumCount", RPCArg::Type::NUM, true},
                          {"minimumSumAmount", RPCArg::Type::AMOUNT, true},
                      },
                      true,
                      "query_options"},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. minconf          (numeric, optional, default=1) The minimum "
             "confirmations to filter\n"
             "2. maxconf          (numeric, optional, default=9999999) The "
             "maximum confirmations to filter\n"
             "3. \"addresses\"      (string, optional) A json array of bitcoin "
             "addresses to filter\n"
             "    [\n"
             "      \"address\"     (string) bitcoin address\n"
             "      ,...\n"
             "    ]\n"
             "4. include_unsafe (bool, optional, default=true) Include outputs "
             "that are not safe to spend\n"
             "                  See description of \"safe\" attribute below.\n"
             "5. query_options    (json, optional) JSON with query options\n"
             "    {\n"
             "      \"minimumAmount\"    (numeric or string, default=0) Minimum "
             "value of each UTXO in " +
             CURRENCY_UNIT +
             "\n"
             "      \"maximumAmount\"    (numeric or string, default=unlimited) "
             "Maximum value of each UTXO in " +
             CURRENCY_UNIT +
             "\n"
             "      \"maximumCount\"     (numeric or string, default=unlimited) "
             "Maximum number of UTXOs\n"
             "      \"minimumSumAmount\" (numeric or string, default=unlimited) "
             "Minimum sum value of all UTXOs in " +
             CURRENCY_UNIT +
             "\n"
             "    }\n"
             "\nResult\n"
             "[                   (array of json object)\n"
             "  {\n"
             "    \"txid\" : \"txid\",          (string) the transaction id \n"
             "    \"vout\" : n,               (numeric) the vout value\n"
             "    \"address\" : \"address\",    (string) the bitcoin address\n"
             "    \"label\" : \"label\",        (string) The associated label, "
             "or \"\" for the default label\n"
             "    \"scriptPubKey\" : \"key\",   (string) the script key\n"
             "    \"amount\" : x.xxx,         (numeric) the transaction output "
             "amount in " +
             CURRENCY_UNIT +
             "\n"
             "    \"confirmations\" : n,      (numeric) The number of "
             "confirmations\n"
             "    \"redeemScript\" : n        (string) The redeemScript if "
             "scriptPubKey is P2SH\n"
             "    \"spendable\" : xxx,        (bool) Whether we have the "
             "private keys to spend this output\n"
             "    \"solvable\" : xxx,         (bool) Whether we know how to "
             "spend this output, ignoring the lack of keys\n"
             "    \"safe\" : xxx              (bool) Whether this output is "
             "considered safe to spend. Unconfirmed transactions\n"
             "                              from outside keys are considered "
             "unsafe and are not eligible for spending by\n"
             "                              fundrawtransaction and "
             "sendtoaddress.\n"
             "  }\n"
             "  ,...\n"
             "]\n"
 
             "\nExamples\n" +
             HelpExampleCli("listunspent", "") +
             HelpExampleCli("listunspent",
                            "6 9999999 "
                            "\"[\\\"1PGFqEzfmQch1gKD3ra4k18PNj3tTUUSqg\\\","
                            "\\\"1LtvqCaApEdUGFkpKMM4MstjcaL4dKg8SP\\\"]\"") +
             HelpExampleRpc("listunspent",
                            "6, 9999999 "
                            "\"[\\\"1PGFqEzfmQch1gKD3ra4k18PNj3tTUUSqg\\\","
                            "\\\"1LtvqCaApEdUGFkpKMM4MstjcaL4dKg8SP\\\"]\"") +
             HelpExampleCli(
                 "listunspent",
                 "6 9999999 '[]' true '{ \"minimumAmount\": 0.005 }'") +
             HelpExampleRpc(
                 "listunspent",
                 "6, 9999999, [] , true, { \"minimumAmount\": 0.005 } "));
     }
 
     int nMinDepth = 1;
     if (!request.params[0].isNull()) {
         RPCTypeCheckArgument(request.params[0], UniValue::VNUM);
         nMinDepth = request.params[0].get_int();
     }
 
     int nMaxDepth = 9999999;
     if (!request.params[1].isNull()) {
         RPCTypeCheckArgument(request.params[1], UniValue::VNUM);
         nMaxDepth = request.params[1].get_int();
     }
 
     std::set<CTxDestination> destinations;
     if (!request.params[2].isNull()) {
         RPCTypeCheckArgument(request.params[2], UniValue::VARR);
         UniValue inputs = request.params[2].get_array();
         for (size_t idx = 0; idx < inputs.size(); idx++) {
             const UniValue &input = inputs[idx];
             CTxDestination dest =
                 DecodeDestination(input.get_str(), config.GetChainParams());
             if (!IsValidDestination(dest)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    std::string("Invalid Bitcoin address: ") +
                                        input.get_str());
             }
             if (!destinations.insert(dest).second) {
                 throw JSONRPCError(
                     RPC_INVALID_PARAMETER,
                     std::string("Invalid parameter, duplicated address: ") +
                         input.get_str());
             }
         }
     }
 
     bool include_unsafe = true;
     if (!request.params[3].isNull()) {
         RPCTypeCheckArgument(request.params[3], UniValue::VBOOL);
         include_unsafe = request.params[3].get_bool();
     }
 
     Amount nMinimumAmount = Amount::zero();
     Amount nMaximumAmount = MAX_MONEY;
     Amount nMinimumSumAmount = MAX_MONEY;
     uint64_t nMaximumCount = 0;
 
     if (!request.params[4].isNull()) {
         const UniValue &options = request.params[4].get_obj();
 
         if (options.exists("minimumAmount")) {
             nMinimumAmount = AmountFromValue(options["minimumAmount"]);
         }
 
         if (options.exists("maximumAmount")) {
             nMaximumAmount = AmountFromValue(options["maximumAmount"]);
         }
 
         if (options.exists("minimumSumAmount")) {
             nMinimumSumAmount = AmountFromValue(options["minimumSumAmount"]);
         }
 
         if (options.exists("maximumCount")) {
             nMaximumCount = options["maximumCount"].get_int64();
         }
     }
 
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     UniValue results(UniValue::VARR);
     std::vector<COutput> vecOutputs;
     {
         auto locked_chain = pwallet->chain().lock();
         LOCK(pwallet->cs_wallet);
         pwallet->AvailableCoins(*locked_chain, vecOutputs, !include_unsafe,
                                 nullptr, nMinimumAmount, nMaximumAmount,
                                 nMinimumSumAmount, nMaximumCount, nMinDepth,
                                 nMaxDepth);
     }
 
     LOCK(pwallet->cs_wallet);
 
     for (const COutput &out : vecOutputs) {
         CTxDestination address;
         const CScript &scriptPubKey = out.tx->tx->vout[out.i].scriptPubKey;
         bool fValidAddress = ExtractDestination(scriptPubKey, address);
 
         if (destinations.size() &&
             (!fValidAddress || !destinations.count(address))) {
             continue;
         }
 
         UniValue entry(UniValue::VOBJ);
         entry.pushKV("txid", out.tx->GetId().GetHex());
         entry.pushKV("vout", out.i);
 
         if (fValidAddress) {
             entry.pushKV("address", EncodeDestination(address, config));
 
             auto i = pwallet->mapAddressBook.find(address);
             if (i != pwallet->mapAddressBook.end()) {
                 entry.pushKV("label", i->second.name);
             }
 
             if (scriptPubKey.IsPayToScriptHash()) {
                 const CScriptID &hash = boost::get<CScriptID>(address);
                 CScript redeemScript;
                 if (pwallet->GetCScript(hash, redeemScript)) {
                     entry.pushKV("redeemScript", HexStr(redeemScript.begin(),
                                                         redeemScript.end()));
                 }
             }
         }
 
         entry.pushKV("scriptPubKey",
                      HexStr(scriptPubKey.begin(), scriptPubKey.end()));
         entry.pushKV("amount", ValueFromAmount(out.tx->tx->vout[out.i].nValue));
         entry.pushKV("confirmations", out.nDepth);
         entry.pushKV("spendable", out.fSpendable);
         entry.pushKV("solvable", out.fSolvable);
         entry.pushKV("safe", out.fSafe);
         results.push_back(entry);
     }
 
     return results;
 }
 
 void FundTransaction(CWallet *const pwallet, CMutableTransaction &tx,
                      Amount &fee_out, int &change_position, UniValue options) {
     // Make sure the results are valid at least up to the most recent block
     // the user could have gotten from another RPC command prior to now
     pwallet->BlockUntilSyncedToCurrentChain();
 
     CCoinControl coinControl;
     change_position = -1;
     bool lockUnspents = false;
     UniValue subtractFeeFromOutputs;
     std::set<int> setSubtractFeeFromOutputs;
 
     if (!options.isNull()) {
         if (options.type() == UniValue::VBOOL) {
             // backward compatibility bool only fallback
             coinControl.fAllowWatchOnly = options.get_bool();
         } else {
             RPCTypeCheckArgument(options, UniValue::VOBJ);
             RPCTypeCheckObj(
                 options,
                 {
                     {"changeAddress", UniValueType(UniValue::VSTR)},
                     {"changePosition", UniValueType(UniValue::VNUM)},
                     {"includeWatching", UniValueType(UniValue::VBOOL)},
                     {"lockUnspents", UniValueType(UniValue::VBOOL)},
                     // will be checked below
                     {"feeRate", UniValueType()},
                     {"subtractFeeFromOutputs", UniValueType(UniValue::VARR)},
                 },
                 true, true);
 
             if (options.exists("changeAddress")) {
                 CTxDestination dest = DecodeDestination(
                     options["changeAddress"].get_str(), pwallet->chainParams);
 
                 if (!IsValidDestination(dest)) {
                     throw JSONRPCError(
                         RPC_INVALID_ADDRESS_OR_KEY,
                         "changeAddress must be a valid bitcoin address");
                 }
 
                 coinControl.destChange = dest;
             }
 
             if (options.exists("changePosition")) {
                 change_position = options["changePosition"].get_int();
             }
 
             if (options.exists("includeWatching")) {
                 coinControl.fAllowWatchOnly =
                     options["includeWatching"].get_bool();
             }
 
             if (options.exists("lockUnspents")) {
                 lockUnspents = options["lockUnspents"].get_bool();
             }
 
             if (options.exists("feeRate")) {
                 coinControl.m_feerate =
                     CFeeRate(AmountFromValue(options["feeRate"]));
                 coinControl.fOverrideFeeRate = true;
             }
 
             if (options.exists("subtractFeeFromOutputs")) {
                 subtractFeeFromOutputs =
                     options["subtractFeeFromOutputs"].get_array();
             }
         }
     }
 
     if (tx.vout.size() == 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "TX must have at least one output");
     }
 
     if (change_position != -1 &&
         (change_position < 0 ||
          (unsigned int)change_position > tx.vout.size())) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "changePosition out of bounds");
     }
 
     for (size_t idx = 0; idx < subtractFeeFromOutputs.size(); idx++) {
         int pos = subtractFeeFromOutputs[idx].get_int();
         if (setSubtractFeeFromOutputs.count(pos)) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Invalid parameter, duplicated position: %d", pos));
         }
         if (pos < 0) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Invalid parameter, negative position: %d", pos));
         }
         if (pos >= int(tx.vout.size())) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Invalid parameter, position too large: %d", pos));
         }
         setSubtractFeeFromOutputs.insert(pos);
     }
 
     std::string strFailReason;
 
     if (!pwallet->FundTransaction(tx, fee_out, change_position, strFailReason,
                                   lockUnspents, setSubtractFeeFromOutputs,
                                   coinControl)) {
         throw JSONRPCError(RPC_WALLET_ERROR, strFailReason);
     }
 }
 
 static UniValue fundrawtransaction(const Config &config,
                                    const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{
                 "fundrawtransaction",
                 "\nAdd inputs to a transaction until it has enough in value to "
                 "meet its out value.\n"
                 "This will not modify existing inputs, and will add at most "
                 "one change output to the outputs.\n"
                 "No existing outputs will be modified unless "
                 "\"subtractFeeFromOutputs\" is specified.\n"
                 "Note that inputs which were signed may need to be resigned "
                 "after completion since in/outputs have been added.\n"
                 "The inputs added will not be signed, use "
                 "signrawtransactionwithkey or signrawtransactionwithwallet for "
                 "that.\n"
                 "Note that all existing inputs must have their previous output "
                 "transaction be in the wallet.\n"
                 "Note that all inputs selected must be of standard form and "
                 "P2SH scripts must be\n"
                 "in the wallet using importaddress or addmultisigaddress (to "
                 "calculate fees).\n"
                 "You can see whether this is the case by checking the "
                 "\"solvable\" field in the listunspent output.\n"
                 "Only pay-to-pubkey, multisig, and P2SH versions thereof are "
                 "currently supported for watch-only\n",
                 {
                     {"hexstring", RPCArg::Type::STR_HEX, false},
                     {"options",
                      RPCArg::Type::OBJ,
                      {
                          {"changeAddress", RPCArg::Type::STR, true},
                          {"changePosition", RPCArg::Type::NUM, true},
                          {"includeWatching", RPCArg::Type::BOOL, true},
                          {"lockUnspents", RPCArg::Type::BOOL, true},
                          {"feeRate", RPCArg::Type::AMOUNT, true},
                          {"subtractFeeFromOutputs",
                           RPCArg::Type::ARR,
                           {
                               {"vout_index", RPCArg::Type::NUM, true},
                           },
                           true},
                      },
                      true,
                      "options"},
                 }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"hexstring\"           (string, required) The hex string of "
             "the raw transaction\n"
             "2. options                 (object, optional)\n"
             "   {\n"
             "     \"changeAddress\"          (string, optional, default pool "
             "address) The bitcoin address to receive the change\n"
             "     \"changePosition\"         (numeric, optional, default "
             "random) The index of the change output\n"
             "     \"includeWatching\"        (boolean, optional, default "
             "false) Also select inputs which are watch only\n"
             "     \"lockUnspents\"           (boolean, optional, default "
             "false) Lock selected unspent outputs\n"
             "     \"feeRate\"                (numeric, optional, default not "
             "set: makes wallet determine the fee) Set a specific fee rate in " +
             CURRENCY_UNIT +
             "/kB\n"
             "     \"subtractFeeFromOutputs\" (array, optional) A json array of "
             "integers.\n"
             "                              The fee will be equally deducted "
             "from the amount of each specified output.\n"
             "                              The outputs are specified by their "
             "zero-based index, before any change output is added.\n"
             "                              Those recipients will receive less "
             "bitcoins than you enter in their corresponding amount field.\n"
             "                              If no outputs are specified here, "
             "the sender pays the fee.\n"
             "                                  [vout_index,...]\n"
             "   }\n"
             "                         for backward compatibility: passing in a "
             "true instead of an object will result in "
             "{\"includeWatching\":true}\n"
             "\nResult:\n"
             "{\n"
             "  \"hex\":       \"value\", (string)  The resulting raw "
             "transaction (hex-encoded string)\n"
             "  \"fee\":       n,         (numeric) Fee in " +
             CURRENCY_UNIT +
             " the resulting transaction pays\n"
             "  \"changepos\": n          (numeric) The position of the added "
             "change output, or -1\n"
             "}\n"
             "\nExamples:\n"
             "\nCreate a transaction with no inputs\n" +
             HelpExampleCli("createrawtransaction",
                            "\"[]\" \"{\\\"myaddress\\\":0.01}\"") +
             "\nAdd sufficient unsigned inputs to meet the output value\n" +
             HelpExampleCli("fundrawtransaction", "\"rawtransactionhex\"") +
             "\nSign the transaction\n" +
             HelpExampleCli("signrawtransactionwithwallet",
                            "\"fundedtransactionhex\"") +
             "\nSend the transaction\n" +
             HelpExampleCli("sendrawtransaction", "\"signedtransactionhex\""));
     }
 
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValueType()});
 
     // parse hex string from parameter
     CMutableTransaction tx;
     if (!DecodeHexTx(tx, request.params[0].get_str())) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
     }
 
     Amount fee;
     int change_position;
     FundTransaction(pwallet, tx, fee, change_position, request.params[1]);
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("hex", EncodeHexTx(CTransaction(tx)));
     result.pushKV("fee", ValueFromAmount(fee));
     result.pushKV("changepos", change_position);
 
     return result;
 }
 
 UniValue signrawtransactionwithwallet(const Config &config,
                                       const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 3) {
         throw std::runtime_error(
             RPCHelpMan{
                 "signrawtransactionwithwallet",
                 "\nSign inputs for raw transaction (serialized, hex-encoded).\n"
                 "The second optional argument (may be null) is an array of "
                 "previous transaction outputs that\n"
                 "this transaction depends on but may not yet be in the block "
                 "chain.\n",
                 {
                     {"hexstring", RPCArg::Type::STR_HEX, false},
                     {"prevtxs",
                      RPCArg::Type::ARR,
                      {
                          {"",
                           RPCArg::Type::OBJ,
                           {
                               {"txid", RPCArg::Type::STR_HEX, false},
                               {"vout", RPCArg::Type::NUM, false},
                               {"scriptPubKey", RPCArg::Type::STR_HEX, false},
                               {"redeemScript", RPCArg::Type::STR_HEX, false},
                               {"amount", RPCArg::Type::AMOUNT, false},
                           },
                           false},
                      },
                      true},
                     {"sighashtype", RPCArg::Type::STR, true},
                 }}
                 .ToString() +
             HelpRequiringPassphrase(pwallet) +
             "\n"
 
             "\nArguments:\n"
             "1. \"hexstring\"                      (string, required) The "
             "transaction hex string\n"
             "2. \"prevtxs\"                        (string, optional) An json "
             "array of previous dependent transaction outputs\n"
             "     [                              (json array of json objects, "
             "or 'null' if none provided)\n"
             "       {\n"
             "         \"txid\":\"id\",               (string, required) The "
             "transaction id\n"
             "         \"vout\":n,                  (numeric, required) The "
             "output number\n"
             "         \"scriptPubKey\": \"hex\",     (string, required) script "
             "key\n"
             "         \"redeemScript\": \"hex\",     (string, required for "
             "P2SH) redeem script\n"
             "         \"amount\": value            (numeric, required) The "
             "amount spent\n"
             "       }\n"
             "       ,...\n"
             "    ]\n"
             "3. \"sighashtype\"                    (string, optional, "
             "default=ALL|FORKID) The signature hash type. Must be one of\n"
             "       \"ALL|FORKID\"\n"
             "       \"NONE|FORKID\"\n"
             "       \"SINGLE|FORKID\"\n"
             "       \"ALL|FORKID|ANYONECANPAY\"\n"
             "       \"NONE|FORKID|ANYONECANPAY\"\n"
             "       \"SINGLE|FORKID|ANYONECANPAY\"\n"
 
             "\nResult:\n"
             "{\n"
             "  \"hex\" : \"value\",                  (string) The hex-encoded "
             "raw transaction with signature(s)\n"
             "  \"complete\" : true|false,          (boolean) If the "
             "transaction has a complete set of signatures\n"
             "  \"errors\" : [                      (json array of objects) "
             "Script verification errors (if there are any)\n"
             "    {\n"
             "      \"txid\" : \"hash\",              (string) The hash of the "
             "referenced, previous transaction\n"
             "      \"vout\" : n,                   (numeric) The index of the "
             "output to spent and used as input\n"
             "      \"scriptSig\" : \"hex\",          (string) The hex-encoded "
             "signature script\n"
             "      \"sequence\" : n,               (numeric) Script sequence "
             "number\n"
             "      \"error\" : \"text\"              (string) Verification or "
             "signing error related to the input\n"
             "    }\n"
             "    ,...\n"
             "  ]\n"
             "}\n"
 
             "\nExamples:\n" +
             HelpExampleCli("signrawtransactionwithwallet", "\"myhex\"") +
             HelpExampleRpc("signrawtransactionwithwallet", "\"myhex\""));
     }
 
     RPCTypeCheck(request.params,
                  {UniValue::VSTR, UniValue::VARR, UniValue::VSTR}, true);
 
     CMutableTransaction mtx;
     if (!DecodeHexTx(mtx, request.params[0].get_str())) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
     }
 
     // Sign the transaction
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
     EnsureWalletIsUnlocked(pwallet);
 
     return SignTransaction(pwallet->chain(), mtx, request.params[1], pwallet,
                            false, request.params[2]);
 }
 
 UniValue generate(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{"generate",
                        "\nMine up to nblocks blocks immediately (before the "
                        "RPC call returns) to an address in the wallet.\n",
                        {
                            {"nblocks", RPCArg::Type::NUM, false},
                            {"maxtries", RPCArg::Type::NUM, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. nblocks      (numeric, required) How many blocks are generated "
             "immediately.\n"
             "2. maxtries     (numeric, optional) How many iterations to try "
             "(default = 1000000).\n"
             "\nResult:\n"
             "[ blockhashes ]     (array) hashes of blocks generated\n"
             "\nExamples:\n"
             "\nGenerate 11 blocks\n" +
             HelpExampleCli("generate", "11"));
     }
 
     int num_generate = request.params[0].get_int();
     uint64_t max_tries = 1000000;
     if (!request.params[1].isNull()) {
         max_tries = request.params[1].get_int();
     }
 
     std::shared_ptr<CReserveScript> coinbase_script;
     pwallet->GetScriptForMining(coinbase_script);
 
     // If the keypool is exhausted, no script is returned at all.  Catch this.
     if (!coinbase_script) {
         throw JSONRPCError(
             RPC_WALLET_KEYPOOL_RAN_OUT,
             "Error: Keypool ran out, please call keypoolrefill first");
     }
 
     // throw an error if no script was provided
     if (coinbase_script->reserveScript.empty()) {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "No coinbase script available");
     }
 
     return generateBlocks(config, coinbase_script, num_generate, max_tries,
                           true);
 }
 
 UniValue rescanblockchain(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{"rescanblockchain",
                        "\nRescan the local blockchain for wallet related "
                        "transactions.\n",
                        {
                            {"start_height", RPCArg::Type::NUM, true},
                            {"stop_height", RPCArg::Type::NUM, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"start_height\"    (numeric, optional) block height where the "
             "rescan should start\n"
             "2. \"stop_height\"     (numeric, optional) the last block height "
             "that should be scanned\n"
             "\nResult:\n"
             "{\n"
             "  \"start_height\"     (numeric) The block height where the "
             "rescan has started. If omitted, rescan started from the genesis "
             "block.\n"
             "  \"stop_height\"      (numeric) The height of the last rescanned "
             "block. If omitted, rescan stopped at the chain tip.\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("rescanblockchain", "100000 120000") +
             HelpExampleRpc("rescanblockchain", "100000 120000"));
     }
 
     WalletRescanReserver reserver(pwallet);
     if (!reserver.reserve()) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
-    CBlockIndex *pindexStart = nullptr;
-    CBlockIndex *pindexStop = nullptr;
-    CBlockIndex *pChainTip = nullptr;
+    int start_height = 0;
+    BlockHash start_block, stop_block;
     {
         auto locked_chain = pwallet->chain().lock();
-        pindexStart = ::ChainActive().Genesis();
-        pChainTip = ::ChainActive().Tip();
+        Optional<int> tip_height = locked_chain->getHeight();
 
         if (!request.params[0].isNull()) {
-            pindexStart = ::ChainActive()[request.params[0].get_int()];
-            if (!pindexStart) {
+            start_height = request.params[0].get_int();
+            if (start_height < 0 || !tip_height || start_height > *tip_height) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER,
                                    "Invalid start_height");
             }
         }
 
+        Optional<int> stop_height;
         if (!request.params[1].isNull()) {
-            pindexStop = ::ChainActive()[request.params[1].get_int()];
-            if (!pindexStop) {
+            stop_height = request.params[1].get_int();
+            if (*stop_height < 0 || !tip_height || *stop_height > *tip_height) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER,
                                    "Invalid stop_height");
-            } else if (pindexStop->nHeight < pindexStart->nHeight) {
+            } else if (*stop_height < start_height) {
                 throw JSONRPCError(
                     RPC_INVALID_PARAMETER,
                     "stop_height must be greater than start_height");
             }
         }
-    }
 
-    // We can't rescan beyond non-pruned blocks, stop and throw an error
-    if (fPruneMode) {
-        auto locked_chain = pwallet->chain().lock();
-        CBlockIndex *block = pindexStop ? pindexStop : pChainTip;
-        while (block && block->nHeight >= pindexStart->nHeight) {
-            if (!block->nStatus.hasData()) {
-                throw JSONRPCError(RPC_MISC_ERROR,
-                                   "Can't rescan beyond pruned data. Use RPC "
-                                   "call getblockchaininfo to determine your "
-                                   "pruned height.");
+        // We can't rescan beyond non-pruned blocks, stop and throw an error
+        if (locked_chain->findPruned(start_height, stop_height)) {
+            throw JSONRPCError(
+                RPC_MISC_ERROR,
+                "Can't rescan beyond pruned data. Use RPC call "
+                "getblockchaininfo to determine your pruned height.");
+        }
+
+        if (tip_height) {
+            start_block = locked_chain->getBlockHash(start_height);
+
+            if (stop_height) {
+                stop_block = locked_chain->getBlockHash(*stop_height);
             }
-            block = block->pprev;
         }
     }
 
-    const CBlockIndex *failed_block, *stopBlock;
     CWallet::ScanResult result = pwallet->ScanForWalletTransactions(
-        pindexStart, pindexStop, reserver, failed_block, stopBlock, true);
-    switch (result) {
+        start_block, stop_block, reserver, true /* fUpdate */);
+    switch (result.status) {
         case CWallet::ScanResult::SUCCESS:
-            // stopBlock set by ScanForWalletTransactions
             break;
         case CWallet::ScanResult::FAILURE:
             throw JSONRPCError(
                 RPC_MISC_ERROR,
                 "Rescan failed. Potentially corrupted data files.");
         case CWallet::ScanResult::USER_ABORT:
             throw JSONRPCError(RPC_MISC_ERROR, "Rescan aborted.");
             // no default case, so the compiler can warn about missing cases
     }
     UniValue response(UniValue::VOBJ);
-    response.pushKV("start_height", pindexStart->nHeight);
-    response.pushKV("stop_height", stopBlock->nHeight);
+    response.pushKV("start_height", start_height);
+    response.pushKV("stop_height",
+                    result.stop_height ? *result.stop_height : UniValue());
     return response;
 }
 
 class DescribeWalletAddressVisitor : public boost::static_visitor<UniValue> {
 public:
     CWallet *const pwallet;
 
     void ProcessSubScript(const CScript &subscript, UniValue &obj,
                           bool include_addresses = false) const {
         // Always present: script type and redeemscript
         std::vector<std::vector<uint8_t>> solutions_data;
         txnouttype which_type = Solver(subscript, solutions_data);
         obj.pushKV("script", GetTxnOutputType(which_type));
         obj.pushKV("hex", HexStr(subscript.begin(), subscript.end()));
 
         CTxDestination embedded;
         UniValue a(UniValue::VARR);
         if (ExtractDestination(subscript, embedded)) {
             // Only when the script corresponds to an address.
             UniValue subobj(UniValue::VOBJ);
             UniValue detail = DescribeAddress(embedded);
             subobj.pushKVs(detail);
             UniValue wallet_detail = boost::apply_visitor(*this, embedded);
             subobj.pushKVs(wallet_detail);
             subobj.pushKV("address", EncodeDestination(embedded, GetConfig()));
             subobj.pushKV("scriptPubKey",
                           HexStr(subscript.begin(), subscript.end()));
             // Always report the pubkey at the top level, so that
             // `getnewaddress()['pubkey']` always works.
             if (subobj.exists("pubkey")) {
                 obj.pushKV("pubkey", subobj["pubkey"]);
             }
             obj.pushKV("embedded", std::move(subobj));
             if (include_addresses) {
                 a.push_back(EncodeDestination(embedded, GetConfig()));
             }
         } else if (which_type == TX_MULTISIG) {
             // Also report some information on multisig scripts (which do not
             // have a corresponding address).
             // TODO: abstract out the common functionality between this logic
             // and ExtractDestinations.
             obj.pushKV("sigsrequired", solutions_data[0][0]);
             UniValue pubkeys(UniValue::VARR);
             for (size_t i = 1; i < solutions_data.size() - 1; ++i) {
                 CPubKey key(solutions_data[i].begin(), solutions_data[i].end());
                 if (include_addresses) {
                     a.push_back(EncodeDestination(key.GetID(), GetConfig()));
                 }
                 pubkeys.push_back(HexStr(key.begin(), key.end()));
             }
             obj.pushKV("pubkeys", std::move(pubkeys));
         }
 
         // The "addresses" field is confusing because it refers to public keys
         // using their P2PKH address. For that reason, only add the 'addresses'
         // field when needed for backward compatibility. New applications can
         // use the 'pubkeys' field for inspecting multisig participants.
         if (include_addresses) {
             obj.pushKV("addresses", std::move(a));
         }
     }
 
     explicit DescribeWalletAddressVisitor(CWallet *_pwallet)
         : pwallet(_pwallet) {}
 
     UniValue operator()(const CNoDestination &dest) const {
         return UniValue(UniValue::VOBJ);
     }
 
     UniValue operator()(const CKeyID &keyID) const {
         UniValue obj(UniValue::VOBJ);
         CPubKey vchPubKey;
         if (pwallet && pwallet->GetPubKey(keyID, vchPubKey)) {
             obj.pushKV("pubkey", HexStr(vchPubKey));
             obj.pushKV("iscompressed", vchPubKey.IsCompressed());
         }
         return obj;
     }
 
     UniValue operator()(const CScriptID &scriptID) const {
         UniValue obj(UniValue::VOBJ);
         CScript subscript;
         if (pwallet && pwallet->GetCScript(scriptID, subscript)) {
             ProcessSubScript(subscript, obj, true);
         }
         return obj;
     }
 };
 
 static UniValue DescribeWalletAddress(CWallet *pwallet,
                                       const CTxDestination &dest) {
     UniValue ret(UniValue::VOBJ);
     UniValue detail = DescribeAddress(dest);
     ret.pushKVs(detail);
     ret.pushKVs(
         boost::apply_visitor(DescribeWalletAddressVisitor(pwallet), dest));
     return ret;
 }
 
 /** Convert CAddressBookData to JSON record.  */
 static UniValue AddressBookDataToJSON(const CAddressBookData &data,
                                       const bool verbose) {
     UniValue ret(UniValue::VOBJ);
     if (verbose) {
         ret.pushKV("name", data.name);
     }
     ret.pushKV("purpose", data.purpose);
     return ret;
 }
 
 UniValue getaddressinfo(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             RPCHelpMan{"getaddressinfo",
                        "\nReturn information about the given bitcoin address. "
                        "Some information requires the address\n"
                        "to be in the wallet.\n",
                        {
                            {"address", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"address\"                    (string, required) The bitcoin "
             "address to get the information of.\n"
             "\nResult:\n"
             "{\n"
             "  \"address\" : \"address\",        (string) The bitcoin address "
             "validated\n"
             "  \"scriptPubKey\" : \"hex\",       (string) The hex-encoded "
             "scriptPubKey generated by the address\n"
             "  \"ismine\" : true|false,        (boolean) If the address is "
             "yours or not\n"
             "  \"iswatchonly\" : true|false,   (boolean) If the address is "
             "watchonly\n"
             "  \"isscript\" : true|false,      (boolean) If the key is a "
             "script\n"
             "  \"ischange\" : true|false,      (boolean) If the address was "
             "used for change output\n"
             "  \"script\" : \"type\"             (string, optional) The output "
             "script type. Only if \"isscript\" is true and the redeemscript is "
             "known. Possible types: nonstandard, pubkey, pubkeyhash, "
             "scripthash, multisig, nulldata\n"
             "  \"hex\" : \"hex\",                (string, optional) The "
             "redeemscript for the p2sh address\n"
             "  \"pubkeys\"                     (string, optional) Array of "
             "pubkeys associated with the known redeemscript (only if "
             "\"script\" is \"multisig\")\n"
             "    [\n"
             "      \"pubkey\"\n"
             "      ,...\n"
             "    ]\n"
             "  \"sigsrequired\" : xxxxx        (numeric, optional) Number of "
             "signatures required to spend multisig output (only if \"script\" "
             "is \"multisig\")\n"
             "  \"pubkey\" : \"publickeyhex\",    (string, optional) The hex "
             "value of the raw public key, for single-key addresses (possibly "
             "embedded in P2SH or P2WSH)\n"
             "  \"embedded\" : {...},           (object, optional) Information "
             "about the address embedded in P2SH or P2WSH, if relevant and "
             "known. It includes all getaddressinfo output fields for the "
             "embedded address, excluding metadata (\"timestamp\", "
             "\"hdkeypath\", \"hdseedid\") and relation to the wallet "
             "(\"ismine\", \"iswatchonly\").\n"
             "  \"iscompressed\" : true|false,  (boolean) If the address is "
             "compressed\n"
             "  \"label\" :  \"label\"         (string) The label associated "
             "with the address, \"\" is the default label\n"
             "  \"timestamp\" : timestamp,      (number, optional) The creation "
             "time of the key if available in seconds since epoch (Jan 1 1970 "
             "GMT)\n"
             "  \"hdkeypath\" : \"keypath\"       (string, optional) The HD "
             "keypath if the key is HD and available\n"
             "  \"hdseedid\" : \"<hash160>\"      (string, optional) The "
             "Hash160 of the HD seed\n"
             "  \"hdmasterkeyid\" : \"<hash160>\" (string, optional) alias for "
             "hdseedid maintained for backwards compatibility. Will be removed "
             "in V0.21.\n"
             "  \"labels\"                      (object) Array of labels "
             "associated with the address.\n"
             "    [\n"
             "      { (json object of label data)\n"
             "        \"name\": \"labelname\" (string) The label\n"
             "        \"purpose\": \"string\" (string) Purpose of address "
             "(\"send\" for sending address, \"receive\" for receiving "
             "address)\n"
             "      },...\n"
             "    ]\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getaddressinfo",
                            "\"1PSSGeFHDnKNxiEyFrD1wcEaHr9hrQDDWc\"") +
             HelpExampleRpc("getaddressinfo",
                            "\"1PSSGeFHDnKNxiEyFrD1wcEaHr9hrQDDWc\""));
     }
 
     LOCK(pwallet->cs_wallet);
 
     UniValue ret(UniValue::VOBJ);
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
 
     // Make sure the destination is valid
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address");
     }
 
     std::string currentAddress = EncodeDestination(dest, config);
     ret.pushKV("address", currentAddress);
 
     CScript scriptPubKey = GetScriptForDestination(dest);
     ret.pushKV("scriptPubKey",
                HexStr(scriptPubKey.begin(), scriptPubKey.end()));
 
     isminetype mine = IsMine(*pwallet, dest);
     ret.pushKV("ismine", bool(mine & ISMINE_SPENDABLE));
     ret.pushKV("iswatchonly", bool(mine & ISMINE_WATCH_ONLY));
     UniValue detail = DescribeWalletAddress(pwallet, dest);
     ret.pushKVs(detail);
     if (pwallet->mapAddressBook.count(dest)) {
         ret.pushKV("label", pwallet->mapAddressBook[dest].name);
     }
     ret.pushKV("ischange", pwallet->IsChange(scriptPubKey));
     const CKeyMetadata *meta = nullptr;
     CKeyID key_id = GetKeyForDestination(*pwallet, dest);
     if (!key_id.IsNull()) {
         auto it = pwallet->mapKeyMetadata.find(key_id);
         if (it != pwallet->mapKeyMetadata.end()) {
             meta = &it->second;
         }
     }
     if (!meta) {
         auto it = pwallet->m_script_metadata.find(CScriptID(scriptPubKey));
         if (it != pwallet->m_script_metadata.end()) {
             meta = &it->second;
         }
     }
     if (meta) {
         ret.pushKV("timestamp", meta->nCreateTime);
         if (!meta->hdKeypath.empty()) {
             ret.pushKV("hdkeypath", meta->hdKeypath);
             ret.pushKV("hdseedid", meta->hd_seed_id.GetHex());
             ret.pushKV("hdmasterkeyid", meta->hd_seed_id.GetHex());
         }
     }
 
     // Currently only one label can be associated with an address, return an
     // array so the API remains stable if we allow multiple labels to be
     // associated with an address.
     UniValue labels(UniValue::VARR);
     std::map<CTxDestination, CAddressBookData>::iterator mi =
         pwallet->mapAddressBook.find(dest);
     if (mi != pwallet->mapAddressBook.end()) {
         labels.push_back(AddressBookDataToJSON(mi->second, true));
     }
     ret.pushKV("labels", std::move(labels));
 
     return ret;
 }
 
 UniValue getaddressesbylabel(const Config &config,
                              const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             RPCHelpMan{"getaddressesbylabel",
                        "\nReturns the list of addresses assigned the specified "
                        "label.\n",
                        {
                            {"label", RPCArg::Type::STR, false},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"label\"  (string, required) The label.\n"
             "\nResult:\n"
             "{ (json object with addresses as keys)\n"
             "  \"address\": { (json object with information about address)\n"
             "    \"purpose\": \"string\" (string)  Purpose of address "
             "(\"send\" for sending address, \"receive\" for receiving "
             "address)\n"
             "  },...\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getaddressesbylabel", "\"tabby\"") +
             HelpExampleRpc("getaddressesbylabel", "\"tabby\""));
     }
 
     LOCK(pwallet->cs_wallet);
 
     std::string label = LabelFromValue(request.params[0]);
 
     // Find all addresses that have the given label
     UniValue ret(UniValue::VOBJ);
     for (const std::pair<const CTxDestination, CAddressBookData> &item :
          pwallet->mapAddressBook) {
         if (item.second.name == label) {
             ret.pushKV(EncodeDestination(item.first, config),
                        AddressBookDataToJSON(item.second, false));
         }
     }
 
     if (ret.empty()) {
         throw JSONRPCError(RPC_WALLET_INVALID_LABEL_NAME,
                            std::string("No addresses with label " + label));
     }
 
     return ret;
 }
 
 UniValue listlabels(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             RPCHelpMan{"listlabels",
                        "\nReturns the list of all labels, or labels that are "
                        "assigned to addresses with a specific purpose.\n",
                        {
                            {"purpose", RPCArg::Type::STR, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"purpose\"    (string, optional) Address purpose to list "
             "labels for ('send','receive'). An empty string is the same as not "
             "providing this argument.\n"
             "\nResult:\n"
             "[               (json array of string)\n"
             "  \"label\",      (string) Label name\n"
             "  ...\n"
             "]\n"
             "\nExamples:\n"
             "\nList all labels\n" +
             HelpExampleCli("listlabels", "") +
             "\nList labels that have receiving addresses\n" +
             HelpExampleCli("listlabels", "receive") +
             "\nList labels that have sending addresses\n" +
             HelpExampleCli("listlabels", "send") + "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("listlabels", "receive"));
     }
 
     LOCK(pwallet->cs_wallet);
 
     std::string purpose;
     if (!request.params[0].isNull()) {
         purpose = request.params[0].get_str();
     }
 
     // Add to a set to sort by label name, then insert into Univalue array
     std::set<std::string> label_set;
     for (const std::pair<const CTxDestination, CAddressBookData> &entry :
          pwallet->mapAddressBook) {
         if (purpose.empty() || entry.second.purpose == purpose) {
             label_set.insert(entry.second.name);
         }
     }
 
     UniValue ret(UniValue::VARR);
     for (const std::string &name : label_set) {
         ret.push_back(name);
     }
 
     return ret;
 }
 
 static UniValue sethdseed(const Config &config, const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             RPCHelpMan{"sethdseed",
                        "\nSet or generate a new HD wallet seed. Non-HD wallets "
                        "will not be upgraded to being a HD wallet. Wallets "
                        "that are already\n"
                        "HD will have a new HD seed set so that new keys added "
                        "to the keypool will be derived from this new seed.\n"
                        "\nNote that you will need to MAKE A NEW BACKUP of your "
                        "wallet after setting the HD wallet seed.\n",
                        {
                            {"newkeypool", RPCArg::Type::BOOL, true},
                            {"seed", RPCArg::Type::STR, true},
                        }}
                 .ToString() +
             HelpRequiringPassphrase(pwallet) +
             "\nArguments:\n"
             "1. \"newkeypool\"         (boolean, optional, default=true) "
             "Whether to flush old unused addresses, including change "
             "addresses, from the keypool and regenerate it.\n"
             "                             If true, the next address from "
             "getnewaddress and change address from getrawchangeaddress will be "
             "from this new seed.\n"
             "                             If false, addresses (including "
             "change addresses if the wallet already had HD Chain Split "
             "enabled) from the existing\n"
             "                             keypool will be used until it has "
             "been depleted.\n"
             "2. \"seed\"               (string, optional) The WIF private key "
             "to use as the new HD seed; if not provided a random seed will be "
             "used.\n"
             "                             The seed value can be retrieved "
             "using the dumpwallet command. It is the private key marked "
             "hdseed=1\n"
             "\nExamples:\n" +
             HelpExampleCli("sethdseed", "") +
             HelpExampleCli("sethdseed", "false") +
             HelpExampleCli("sethdseed", "true \"wifkey\"") +
             HelpExampleRpc("sethdseed", "true, \"wifkey\""));
     }
 
     if (IsInitialBlockDownload()) {
         throw JSONRPCError(
             RPC_CLIENT_IN_INITIAL_DOWNLOAD,
             "Cannot set a new HD seed while still in Initial Block Download");
     }
 
     if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Cannot set a HD seed to a wallet with private keys disabled");
     }
 
     auto locked_chain = pwallet->chain().lock();
     LOCK(pwallet->cs_wallet);
 
     // Do not do anything to non-HD wallets
     if (!pwallet->CanSupportFeature(FEATURE_HD)) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
             "Cannot set a HD seed on a non-HD wallet. Start with "
             "-upgradewallet in order to upgrade a non-HD wallet to HD");
     }
 
     EnsureWalletIsUnlocked(pwallet);
 
     bool flush_key_pool = true;
     if (!request.params[0].isNull()) {
         flush_key_pool = request.params[0].get_bool();
     }
 
     CPubKey master_pub_key;
     if (request.params[1].isNull()) {
         master_pub_key = pwallet->GenerateNewSeed();
     } else {
         CKey key = DecodeSecret(request.params[1].get_str());
         if (!key.IsValid()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Invalid private key");
         }
 
         if (HaveKey(*pwallet, key)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Already have this key (either as an HD seed or "
                                "as a loose private key)");
         }
 
         master_pub_key = pwallet->DeriveNewSeed(key);
     }
 
     pwallet->SetHDSeed(master_pub_key);
     if (flush_key_pool) {
         pwallet->NewKeyPool();
     }
 
     return NullUniValue;
 }
 
 bool FillPSBT(const CWallet *pwallet, PartiallySignedTransaction &psbtx,
               const CTransaction *txConst, SigHashType sighash_type, bool sign,
               bool bip32derivs) {
     LOCK(pwallet->cs_wallet);
     // Get all of the previous transactions
     bool complete = true;
     for (size_t i = 0; i < txConst->vin.size(); ++i) {
         const CTxIn &txin = txConst->vin[i];
         PSBTInput &input = psbtx.inputs.at(i);
 
         // If we don't know about this input, skip it and let someone else deal
         // with it
         const TxId &txid = txin.prevout.GetTxId();
         const auto it = pwallet->mapWallet.find(txid);
         if (it != pwallet->mapWallet.end()) {
             const CWalletTx &wtx = it->second;
             CTxOut utxo = wtx.tx->vout[txin.prevout.GetN()];
             // Update UTXOs from the wallet.
             input.utxo = utxo;
         }
 
         // Get the Sighash type
         if (sign && input.sighash_type.getRawSigHashType() > 0 &&
             input.sighash_type != sighash_type) {
             throw JSONRPCError(
                 RPC_DESERIALIZATION_ERROR,
                 "Specified sighash and sighash in PSBT do not match.");
         }
 
         complete &=
             SignPSBTInput(HidingSigningProvider(pwallet, !sign, !bip32derivs),
                           *psbtx.tx, input, i, sighash_type);
     }
 
     // Fill in the bip32 keypaths and redeemscripts for the outputs so that
     // hardware wallets can identify change
     for (size_t i = 0; i < txConst->vout.size(); ++i) {
         const CTxOut &out = txConst->vout.at(i);
         PSBTOutput &psbt_out = psbtx.outputs.at(i);
 
         // Fill a SignatureData with output info
         SignatureData sigdata;
         psbt_out.FillSignatureData(sigdata);
 
         MutableTransactionSignatureCreator creator(
             psbtx.tx.get_ptr(), 0, out.nValue, SigHashType().withForkId());
         ProduceSignature(HidingSigningProvider(pwallet, true, !bip32derivs),
                          creator, out.scriptPubKey, sigdata);
         psbt_out.FromSignatureData(sigdata);
     }
     return complete;
 }
 
 static UniValue walletprocesspsbt(const Config &config,
                                   const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 4) {
         throw std::runtime_error(
             RPCHelpMan{"walletprocesspsbt",
                        "\nUpdate a PSBT with input information from our wallet "
                        "and then sign inputs that we can sign for.\n",
                        {
                            {"psbt", RPCArg::Type::STR, false},
                            {"sign", RPCArg::Type::BOOL, true},
                            {"sighashtype", RPCArg::Type::STR, true},
                            {"bip32derivs", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             HelpRequiringPassphrase(pwallet) +
             "\n"
 
             "\nArguments:\n"
             "1. \"psbt\"                      (string, required) The "
             "transaction base64 string\n"
             "2. sign                          (boolean, optional, "
             "default=true) Also sign the transaction when updating\n"
             "3. \"sighashtype\"            (string, optional, "
             "default=ALL|FORKID) The signature hash type to sign with if not "
             "specified by the PSBT. Must be one of\n"
             "       \"ALL|FORKID\"\n"
             "       \"NONE|FORKID\"\n"
             "       \"SINGLE|FORKID\"\n"
             "       \"ALL|FORKID|ANYONECANPAY\"\n"
             "       \"NONE|FORKID|ANYONECANPAY\"\n"
             "       \"SINGLE|FORKID|ANYONECANPAY\"\n"
             "4. bip32derivs                    (boolean, optional, "
             "default=false) If true, includes the BIP 32 derivation paths for "
             "public keys if we know them\n"
 
             "\nResult:\n"
             "{\n"
             "  \"psbt\" : \"value\",          (string) The base64-encoded "
             "partially signed transaction\n"
             "  \"complete\" : true|false,   (boolean) If the transaction has a "
             "complete set of signatures\n"
             "  ]\n"
             "}\n"
 
             "\nExamples:\n" +
             HelpExampleCli("walletprocesspsbt", "\"psbt\""));
     }
 
     RPCTypeCheck(request.params,
                  {UniValue::VSTR, UniValue::VBOOL, UniValue::VSTR});
 
     // Unserialize the transaction
     PartiallySignedTransaction psbtx;
     std::string error;
     if (!DecodePSBT(psbtx, request.params[0].get_str(), error)) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                            strprintf("TX decode failed %s", error));
     }
 
     // Get the sighash type
     SigHashType nHashType = ParseSighashString(request.params[2]);
     if (!nHashType.hasForkId()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Signature must use SIGHASH_FORKID");
     }
 
     // Use CTransaction for the constant parts of the
     // transaction to avoid rehashing.
     const CTransaction txConst(*psbtx.tx);
 
     // Fill transaction with our data and also sign
     bool sign =
         request.params[1].isNull() ? true : request.params[1].get_bool();
     bool bip32derivs =
         request.params[3].isNull() ? false : request.params[3].get_bool();
     bool complete =
         FillPSBT(pwallet, psbtx, &txConst, nHashType, sign, bip32derivs);
 
     UniValue result(UniValue::VOBJ);
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
     ssTx << psbtx;
     result.pushKV("psbt", EncodeBase64((uint8_t *)ssTx.data(), ssTx.size()));
     result.pushKV("complete", complete);
 
     return result;
 }
 
 static UniValue walletcreatefundedpsbt(const Config &config,
                                        const JSONRPCRequest &request) {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     CWallet *const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 5) {
         throw std::runtime_error(
             RPCHelpMan{"walletcreatefundedpsbt",
                        "\nCreates and funds a transaction in the Partially "
                        "Signed Transaction format. Inputs will be added if "
                        "supplied inputs are not enough\n"
                        "Implements the Creator and Updater roles.\n",
                        {
                            {"inputs",
                             RPCArg::Type::ARR,
                             {
                                 {"",
                                  RPCArg::Type::OBJ,
                                  {
                                      {"txid", RPCArg::Type::STR_HEX, false},
                                      {"vout", RPCArg::Type::NUM, false},
                                      {"sequence", RPCArg::Type::NUM, true},
                                  },
                                  false},
                             },
                             false},
                            {"outputs",
                             RPCArg::Type::ARR,
                             {
                                 {"",
                                  RPCArg::Type::OBJ,
                                  {
                                      {"address", RPCArg::Type::AMOUNT, true},
                                  },
                                  true},
                                 {"",
                                  RPCArg::Type::OBJ,
                                  {
                                      {"data", RPCArg::Type::STR_HEX, true},
                                  },
                                  true},
                             },
                             false},
                            {"locktime", RPCArg::Type::NUM, true},
                            {"options",
                             RPCArg::Type::OBJ,
                             {
                                 {"changeAddress", RPCArg::Type::STR, true},
                                 {"changePosition", RPCArg::Type::NUM, true},
                                 {"includeWatching", RPCArg::Type::BOOL, true},
                                 {"lockUnspents", RPCArg::Type::BOOL, true},
                                 {"feeRate", RPCArg::Type::AMOUNT, true},
                                 {"subtractFeeFromOutputs",
                                  RPCArg::Type::ARR,
                                  {
                                      {"int", RPCArg::Type::NUM, true},
                                  },
                                  true,
                                  "options"},
                             },
                             true},
                            {"bip32derivs", RPCArg::Type::BOOL, true},
                        }}
                 .ToString() +
             "\nArguments:\n"
             "1. \"inputs\"                (array, required) A json array of "
             "json objects\n"
             "     [\n"
             "       {\n"
             "         \"txid\":\"id\",      (string, required) The transaction "
             "id\n"
             "         \"vout\":n,         (numeric, required) The output "
             "number\n"
             "         \"sequence\":n      (numeric, optional) The sequence "
             "number\n"
             "       } \n"
             "       ,...\n"
             "     ]\n"
             "2. \"outputs\"               (array, required) a json array with "
             "outputs (key-value pairs)\n"
             "   [\n"
             "    {\n"
             "      \"address\": x.xxx,    (obj, optional) A key-value pair. "
             "The key (string) is the bitcoin address, the value (float or "
             "string) is the amount in " +
             CURRENCY_UNIT +
             "\n"
             "    },\n"
             "    {\n"
             "      \"data\": \"hex\"        (obj, optional) A key-value pair. "
             "The key must be \"data\", the value is hex-encoded data\n"
             "    }\n"
             "    ,...                     More key-value pairs of the above "
             "form. For compatibility reasons, a dictionary, which holds the "
             "key-value pairs directly, is also\n"
             "                             accepted as second parameter.\n"
             "   ]\n"
             "3. locktime                  (numeric, optional, default=0) Raw "
             "locktime. Non-0 value also locktime-activates inputs\n"
             "4. options                 (object, optional)\n"
             "   {\n"
             "     \"changeAddress\"          (string, optional, default pool "
             "address) The bitcoin address to receive the change\n"
             "     \"changePosition\"         (numeric, optional, default "
             "random) The index of the change output\n"
             "     \"includeWatching\"        (boolean, optional, default "
             "false) Also select inputs which are watch only\n"
             "     \"lockUnspents\"           (boolean, optional, default "
             "false) Lock selected unspent outputs\n"
             "     \"feeRate\"                (numeric, optional, default not "
             "set: makes wallet determine the fee) Set a specific fee rate in " +
             CURRENCY_UNIT +
             "/kB\n"
             "     \"subtractFeeFromOutputs\" (array, optional) A json array of "
             "integers.\n"
             "                              The fee will be equally deducted "
             "from the amount of each specified output.\n"
             "                              The outputs are specified by their "
             "zero-based index, before any change output is added.\n"
             "                              Those recipients will receive less "
             "bitcoins than you enter in their corresponding amount field.\n"
             "                              If no outputs are specified here, "
             "the sender pays the fee.\n"
             "                                  [vout_index,...]\n"
             "   }\n"
             "5. bip32derivs                    (boolean, optional, "
             "default=false) If true, includes the BIP 32 derivation paths for "
             "public keys if we know them\n"
             "\nResult:\n"
             "{\n"
             "  \"psbt\": \"value\",        (string)  The resulting raw "
             "transaction (base64-encoded string)\n"
             "  \"fee\":       n,         (numeric) Fee in " +
             CURRENCY_UNIT +
             " the resulting transaction pays\n"
             "  \"changepos\": n          (numeric) The position of the added "
             "change output, or -1\n"
             "}\n"
             "\nExamples:\n"
             "\nCreate a transaction with no inputs\n" +
             HelpExampleCli("walletcreatefundedpsbt",
                            "\"[{\\\"txid\\\":\\\"myid\\\",\\\"vout\\\":0}]\" "
                            "\"[{\\\"data\\\":\\\"00010203\\\"}]\""));
     }
 
     RPCTypeCheck(request.params,
                  {UniValue::VARR,
                   UniValueType(), // ARR or OBJ, checked later
                   UniValue::VNUM, UniValue::VOBJ},
                  true);
 
     Amount fee;
     int change_position;
     CMutableTransaction rawTx =
         ConstructTransaction(config.GetChainParams(), request.params[0],
                              request.params[1], request.params[2]);
     FundTransaction(pwallet, rawTx, fee, change_position, request.params[3]);
 
     // Make a blank psbt
     PartiallySignedTransaction psbtx;
     psbtx.tx = rawTx;
     for (size_t i = 0; i < rawTx.vin.size(); ++i) {
         psbtx.inputs.push_back(PSBTInput());
     }
     for (size_t i = 0; i < rawTx.vout.size(); ++i) {
         psbtx.outputs.push_back(PSBTOutput());
     }
 
     // Use CTransaction for the constant parts of the
     // transaction to avoid rehashing.
     const CTransaction txConst(*psbtx.tx);
 
     // Fill transaction with out data but don't sign
     bool bip32derivs =
         request.params[4].isNull() ? false : request.params[4].get_bool();
     FillPSBT(pwallet, psbtx, &txConst, SigHashType().withForkId(), false,
              bip32derivs);
 
     // Serialize the PSBT
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
     ssTx << psbtx;
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("psbt", EncodeBase64((uint8_t *)ssTx.data(), ssTx.size()));
     result.pushKV("fee", ValueFromAmount(fee));
     result.pushKV("changepos", change_position);
     return result;
 }
 
 // clang-format off
 static const ContextFreeRPCCommand commands[] = {
     //  category            name                            actor (function)              argNames
     //  ------------------- ------------------------        ----------------------        ----------
     { "generating",         "generate",                     generate,                     {"nblocks","maxtries"} },
     { "hidden",             "resendwallettransactions",     resendwallettransactions,     {} },
     { "rawtransactions",    "fundrawtransaction",           fundrawtransaction,           {"hexstring","options"} },
     { "wallet",             "abandontransaction",           abandontransaction,           {"txid"} },
     { "wallet",             "addmultisigaddress",           addmultisigaddress,           {"nrequired","keys","label"} },
     { "wallet",             "backupwallet",                 backupwallet,                 {"destination"} },
     { "wallet",             "createwallet",                 createwallet,                 {"wallet_name", "disable_private_keys", "blank"} },
     { "wallet",             "encryptwallet",                encryptwallet,                {"passphrase"} },
     { "wallet",             "getaddressesbylabel",          getaddressesbylabel,          {"label"} },
     { "wallet",             "getaddressinfo",               getaddressinfo,               {"address"} },
     { "wallet",             "getbalance",                   getbalance,                   {"dummy","minconf","include_watchonly"} },
     { "wallet",             "getnewaddress",                getnewaddress,                {"label", "address_type"} },
     { "wallet",             "getrawchangeaddress",          getrawchangeaddress,          {"address_type"} },
     { "wallet",             "getreceivedbyaddress",         getreceivedbyaddress,         {"address","minconf"} },
     { "wallet",             "getreceivedbylabel",           getreceivedbylabel,           {"label","minconf"} },
     { "wallet",             "gettransaction",               gettransaction,               {"txid","include_watchonly"} },
     { "wallet",             "getunconfirmedbalance",        getunconfirmedbalance,        {} },
     { "wallet",             "getwalletinfo",                getwalletinfo,                {} },
     { "wallet",             "keypoolrefill",                keypoolrefill,                {"newsize"} },
     { "wallet",             "listaddressgroupings",         listaddressgroupings,         {} },
     { "wallet",             "listlabels",                   listlabels,                   {"purpose"} },
     { "wallet",             "listlockunspent",              listlockunspent,              {} },
     { "wallet",             "listreceivedbyaddress",        listreceivedbyaddress,        {"minconf","include_empty","include_watchonly","address_filter"} },
     { "wallet",             "listreceivedbylabel",          listreceivedbylabel,          {"minconf","include_empty","include_watchonly"} },
     { "wallet",             "listsinceblock",               listsinceblock,               {"blockhash","target_confirmations","include_watchonly","include_removed"} },
     { "wallet",             "listtransactions",             listtransactions,             {"label|dummy","count","skip","include_watchonly"} },
     { "wallet",             "listunspent",                  listunspent,                  {"minconf","maxconf","addresses","include_unsafe","query_options"} },
     { "wallet",             "listwalletdir",                listwalletdir,                {} },
     { "wallet",             "listwallets",                  listwallets,                  {} },
     { "wallet",             "loadwallet",                   loadwallet,                   {"filename"} },
     { "wallet",             "lockunspent",                  lockunspent,                  {"unlock","transactions"} },
     { "wallet",             "rescanblockchain",             rescanblockchain,             {"start_height", "stop_height"} },
     { "wallet",             "sendmany",                     sendmany,                     {"dummy","amounts","minconf","comment","subtractfeefrom"} },
     { "wallet",             "sendtoaddress",                sendtoaddress,                {"address","amount","comment","comment_to","subtractfeefromamount"} },
     { "wallet",             "sethdseed",                    sethdseed,                    {"newkeypool","seed"} },
     { "wallet",             "setlabel",                     setlabel,                     {"address","label"} },
     { "wallet",             "settxfee",                     settxfee,                     {"amount"} },
     { "wallet",             "signmessage",                  signmessage,                  {"address","message"} },
     { "wallet",             "signrawtransactionwithwallet", signrawtransactionwithwallet, {"hextring","prevtxs","sighashtype"} },
     { "wallet",             "unloadwallet",                 unloadwallet,                 {"wallet_name"} },
     { "wallet",             "walletcreatefundedpsbt",       walletcreatefundedpsbt,       {"inputs","outputs","locktime","options","bip32derivs"} },
     { "wallet",             "walletlock",                   walletlock,                   {} },
     { "wallet",             "walletpassphrase",             walletpassphrase,             {"passphrase","timeout"} },
     { "wallet",             "walletpassphrasechange",       walletpassphrasechange,       {"oldpassphrase","newpassphrase"} },
     { "wallet",             "walletprocesspsbt",            walletprocesspsbt,            {"psbt","sign","sighashtype","bip32derivs"} },
 };
 // clang-format on
 
 void RegisterWalletRPCCommands(CRPCTable &t) {
     for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++) {
         t.appendCommand(commands[vcidx].name, &commands[vcidx]);
     }
 }
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 8fcee0d0a4..bb995ba5c3 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -1,503 +1,493 @@
 // Copyright (c) 2012-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/validation.h>
 #include <interfaces/chain.h>
 #include <rpc/server.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/rpcdump.h>
 #include <wallet/wallet.h>
 
 #include <test/setup_common.h>
 #include <wallet/test/wallet_test_fixture.h>
 
 #include <boost/test/unit_test.hpp>
 
 #include <univalue.h>
 
 #include <cstdint>
 #include <memory>
 #include <vector>
 
 BOOST_FIXTURE_TEST_SUITE(wallet_tests, WalletTestingSetup)
 
 static void AddKey(CWallet &wallet, const CKey &key) {
     LOCK(wallet.cs_wallet);
     wallet.AddKeyPubKey(key, key.GetPubKey());
 }
 
 BOOST_FIXTURE_TEST_CASE(scan_for_wallet_transactions, TestChain100Setup) {
     auto chain = interfaces::MakeChain();
 
     // Cap last block file size, and mine new block in a new block file.
-    const CBlockIndex *const null_block = nullptr;
     CBlockIndex *oldTip = ::ChainActive().Tip();
     GetBlockFileInfo(oldTip->GetBlockPos().nFile)->nSize = MAX_BLOCKFILE_SIZE;
     CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
     CBlockIndex *newTip = ::ChainActive().Tip();
 
     LockAnnotation lock(::cs_main);
     auto locked_chain = chain->lock();
 
     // Verify ScanForWalletTransactions accommodates a null start block.
     {
         CWallet wallet(Params(), *chain, WalletLocation(),
                        WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
-        const CBlockIndex *stop_block = null_block + 1,
-                          *failed_block = null_block + 1;
-        BOOST_CHECK_EQUAL(
-            wallet.ScanForWalletTransactions(nullptr, nullptr, reserver,
-                                             failed_block, stop_block),
-            CWallet::ScanResult::SUCCESS);
-        BOOST_CHECK_EQUAL(failed_block, null_block);
-        BOOST_CHECK_EQUAL(stop_block, null_block);
+        CWallet::ScanResult result = wallet.ScanForWalletTransactions(
+            BlockHash(), BlockHash(), reserver, false /* update */);
+        BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::SUCCESS);
+        BOOST_CHECK(result.failed_block.IsNull());
+        BOOST_CHECK(result.stop_block.IsNull());
+        BOOST_CHECK(!result.stop_height);
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), Amount::zero());
     }
 
     // Verify ScanForWalletTransactions picks up transactions in both the old
     // and new block files.
     {
         CWallet wallet(Params(), *chain, WalletLocation(),
                        WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
-        const CBlockIndex *stop_block = null_block + 1,
-                          *failed_block = null_block + 1;
-        BOOST_CHECK_EQUAL(
-            wallet.ScanForWalletTransactions(oldTip, nullptr, reserver,
-                                             failed_block, stop_block),
-            CWallet::ScanResult::SUCCESS);
-        BOOST_CHECK_EQUAL(failed_block, null_block);
-        BOOST_CHECK_EQUAL(stop_block, newTip);
+        CWallet::ScanResult result = wallet.ScanForWalletTransactions(
+            oldTip->GetBlockHash(), BlockHash(), reserver, false /* update */);
+        BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::SUCCESS);
+        BOOST_CHECK(result.failed_block.IsNull());
+        BOOST_CHECK_EQUAL(result.stop_block, newTip->GetBlockHash());
+        BOOST_CHECK_EQUAL(*result.stop_height, newTip->nHeight);
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 100 * COIN);
     }
 
     // Prune the older block file.
     PruneOneBlockFile(oldTip->GetBlockPos().nFile);
     UnlinkPrunedFiles({oldTip->GetBlockPos().nFile});
 
     // Verify ScanForWalletTransactions only picks transactions in the new block
     // file.
     {
         CWallet wallet(Params(), *chain, WalletLocation(),
                        WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
-        const CBlockIndex *stop_block = null_block + 1,
-                          *failed_block = null_block + 1;
-        BOOST_CHECK_EQUAL(
-            wallet.ScanForWalletTransactions(oldTip, nullptr, reserver,
-                                             failed_block, stop_block),
-            CWallet::ScanResult::FAILURE);
-        BOOST_CHECK_EQUAL(failed_block, oldTip);
-        BOOST_CHECK_EQUAL(stop_block, newTip);
+        CWallet::ScanResult result = wallet.ScanForWalletTransactions(
+            oldTip->GetBlockHash(), BlockHash(), reserver, false /* update */);
+        BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::FAILURE);
+        BOOST_CHECK_EQUAL(result.failed_block, oldTip->GetBlockHash());
+        BOOST_CHECK_EQUAL(result.stop_block, newTip->GetBlockHash());
+        BOOST_CHECK_EQUAL(*result.stop_height, newTip->nHeight);
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 50 * COIN);
     }
 
     // Prune the remaining block file.
     PruneOneBlockFile(newTip->GetBlockPos().nFile);
     UnlinkPrunedFiles({newTip->GetBlockPos().nFile});
 
     // Verify ScanForWalletTransactions scans no blocks.
     {
         CWallet wallet(Params(), *chain, WalletLocation(),
                        WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
-        const CBlockIndex *stop_block = null_block + 1,
-                          *failed_block = null_block + 1;
-        BOOST_CHECK_EQUAL(
-            wallet.ScanForWalletTransactions(oldTip, nullptr, reserver,
-                                             failed_block, stop_block),
-            CWallet::ScanResult::FAILURE);
-        BOOST_CHECK_EQUAL(failed_block, newTip);
-        BOOST_CHECK_EQUAL(stop_block, null_block);
+        CWallet::ScanResult result = wallet.ScanForWalletTransactions(
+            oldTip->GetBlockHash(), BlockHash(), reserver, false /* update */);
+        BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::FAILURE);
+        BOOST_CHECK_EQUAL(result.failed_block, newTip->GetBlockHash());
+        BOOST_CHECK(result.stop_block.IsNull());
+        BOOST_CHECK(!result.stop_height);
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), Amount::zero());
     }
 }
 
 BOOST_FIXTURE_TEST_CASE(importmulti_rescan, TestChain100Setup) {
     auto chain = interfaces::MakeChain();
 
     // Cap last block file size, and mine new block in a new block file.
     CBlockIndex *oldTip = ::ChainActive().Tip();
     GetBlockFileInfo(oldTip->GetBlockPos().nFile)->nSize = MAX_BLOCKFILE_SIZE;
     CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
     CBlockIndex *newTip = ::ChainActive().Tip();
 
     LockAnnotation lock(::cs_main);
     auto locked_chain = chain->lock();
 
     // Prune the older block file.
     PruneOneBlockFile(oldTip->GetBlockPos().nFile);
     UnlinkPrunedFiles({oldTip->GetBlockPos().nFile});
 
     // Verify importmulti RPC returns failure for a key whose creation time is
     // before the missing block, and success for a key whose creation time is
     // after.
     {
         std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
             Params(), *chain, WalletLocation(), WalletDatabase::CreateDummy());
         AddWallet(wallet);
         UniValue keys;
         keys.setArray();
         UniValue key;
         key.setObject();
         key.pushKV("scriptPubKey",
                    HexStr(GetScriptForRawPubKey(coinbaseKey.GetPubKey())));
         key.pushKV("timestamp", 0);
         key.pushKV("internal", UniValue(true));
         keys.push_back(key);
         key.clear();
         key.setObject();
         CKey futureKey;
         futureKey.MakeNewKey(true);
         key.pushKV("scriptPubKey",
                    HexStr(GetScriptForRawPubKey(futureKey.GetPubKey())));
         key.pushKV("timestamp",
                    newTip->GetBlockTimeMax() + TIMESTAMP_WINDOW + 1);
         key.pushKV("internal", UniValue(true));
         keys.push_back(key);
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(keys);
 
         UniValue response = importmulti(GetConfig(), request);
         BOOST_CHECK_EQUAL(
             response.write(),
             strprintf("[{\"success\":false,\"error\":{\"code\":-1,\"message\":"
                       "\"Rescan failed for key with creation timestamp %d. "
                       "There was an error reading a block from time %d, which "
                       "is after or within %d seconds of key creation, and "
                       "could contain transactions pertaining to the key. As a "
                       "result, transactions and coins using this key may not "
                       "appear in the wallet. This error could be caused by "
                       "pruning or data corruption (see bitcoind log for "
                       "details) and could be dealt with by downloading and "
                       "rescanning the relevant blocks (see -reindex and "
                       "-rescan options).\"}},{\"success\":true}]",
                       0, oldTip->GetBlockTimeMax(), TIMESTAMP_WINDOW));
         RemoveWallet(wallet);
     }
 }
 
 // Verify importwallet RPC starts rescan at earliest block with timestamp
 // greater or equal than key birthday. Previously there was a bug where
 // importwallet RPC would start the scan at the latest block with timestamp less
 // than or equal to key birthday.
 BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup) {
     auto chain = interfaces::MakeChain();
 
     // Create two blocks with same timestamp to verify that importwallet rescan
     // will pick up both blocks, not just the first.
     const int64_t BLOCK_TIME = ::ChainActive().Tip()->GetBlockTimeMax() + 5;
     SetMockTime(BLOCK_TIME);
     m_coinbase_txns.emplace_back(
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
             .vtx[0]);
     m_coinbase_txns.emplace_back(
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
             .vtx[0]);
 
     // Set key birthday to block time increased by the timestamp window, so
     // rescan will start at the block time.
     const int64_t KEY_TIME = BLOCK_TIME + TIMESTAMP_WINDOW;
     SetMockTime(KEY_TIME);
     m_coinbase_txns.emplace_back(
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
             .vtx[0]);
 
     auto locked_chain = chain->lock();
 
     std::string backup_file = (GetDataDir() / "wallet.backup").string();
 
     // Import key into wallet and call dumpwallet to create backup file.
     {
         std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
             Params(), *chain, WalletLocation(), WalletDatabase::CreateDummy());
         LOCK(wallet->cs_wallet);
         wallet->mapKeyMetadata[coinbaseKey.GetPubKey().GetID()].nCreateTime =
             KEY_TIME;
         wallet->AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
 
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(backup_file);
         AddWallet(wallet);
         ::dumpwallet(GetConfig(), request);
         RemoveWallet(wallet);
     }
 
     // Call importwallet RPC and verify all blocks with timestamps >= BLOCK_TIME
     // were scanned, and no prior blocks were scanned.
     {
         std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
             Params(), *chain, WalletLocation(), WalletDatabase::CreateDummy());
 
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(backup_file);
         AddWallet(wallet);
         ::importwallet(GetConfig(), request);
         RemoveWallet(wallet);
 
         LOCK(wallet->cs_wallet);
         BOOST_CHECK_EQUAL(wallet->mapWallet.size(), 3U);
         BOOST_CHECK_EQUAL(m_coinbase_txns.size(), 103U);
         for (size_t i = 0; i < m_coinbase_txns.size(); ++i) {
             bool found = wallet->GetWalletTx(m_coinbase_txns[i]->GetId());
             bool expected = i >= 100;
             BOOST_CHECK_EQUAL(found, expected);
         }
     }
 
     SetMockTime(0);
 }
 
 // Check that GetImmatureCredit() returns a newly calculated value instead of
 // the cached value after a MarkDirty() call.
 //
 // This is a regression test written to verify a bugfix for the immature credit
 // function. Similar tests probably should be written for the other credit and
 // debit functions.
 BOOST_FIXTURE_TEST_CASE(coin_mark_dirty_immature_credit, TestChain100Setup) {
     auto chain = interfaces::MakeChain();
     CWallet wallet(Params(), *chain, WalletLocation(),
                    WalletDatabase::CreateDummy());
     CWalletTx wtx(&wallet, m_coinbase_txns.back());
     auto locked_chain = chain->lock();
     LOCK(wallet.cs_wallet);
     wtx.hashBlock = ::ChainActive().Tip()->GetBlockHash();
     wtx.nIndex = 0;
 
     // Call GetImmatureCredit() once before adding the key to the wallet to
     // cache the current immature credit amount, which is 0.
     BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(*locked_chain), Amount::zero());
 
     // Invalidate the cached value, add the key, and make sure a new immature
     // credit amount is calculated.
     wtx.MarkDirty();
     wallet.AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
     BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(*locked_chain), 50 * COIN);
 }
 
 static int64_t AddTx(CWallet &wallet, uint32_t lockTime, int64_t mockTime,
                      int64_t blockTime) {
     CMutableTransaction tx;
     tx.nLockTime = lockTime;
     SetMockTime(mockTime);
     CBlockIndex *block = nullptr;
     if (blockTime > 0) {
         LockAnnotation lock(::cs_main);
         auto locked_chain = wallet.chain().lock();
         auto inserted =
             mapBlockIndex.emplace(BlockHash(GetRandHash()), new CBlockIndex);
         assert(inserted.second);
         const BlockHash &hash = inserted.first->first;
         block = inserted.first->second;
         block->nTime = blockTime;
         block->phashBlock = &hash;
     }
 
     CWalletTx wtx(&wallet, MakeTransactionRef(tx));
     if (block) {
-        wtx.SetMerkleBranch(block, 0);
+        wtx.SetMerkleBranch(block->GetBlockHash(), 0);
     }
     {
         LOCK(cs_main);
         wallet.AddToWallet(wtx);
     }
     LOCK(wallet.cs_wallet);
     return wallet.mapWallet.at(wtx.GetId()).nTimeSmart;
 }
 
 // Simple test to verify assignment of CWalletTx::nSmartTime value. Could be
 // expanded to cover more corner cases of smart time logic.
 BOOST_AUTO_TEST_CASE(ComputeTimeSmart) {
     // New transaction should use clock time if lower than block time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 1, 100, 120), 100);
 
     // Test that updating existing transaction does not change smart time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 1, 200, 220), 100);
 
     // New transaction should use clock time if there's no block time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 2, 300, 0), 300);
 
     // New transaction should use block time if lower than clock time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 3, 420, 400), 400);
 
     // New transaction should use latest entry time if higher than
     // min(block time, clock time).
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 4, 500, 390), 400);
 
     // If there are future entries, new transaction should use time of the
     // newest entry that is no more than 300 seconds ahead of the clock time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 5, 50, 600), 300);
 
     // Reset mock time for other tests.
     SetMockTime(0);
 }
 
 BOOST_AUTO_TEST_CASE(LoadReceiveRequests) {
     CTxDestination dest = CKeyID();
     LOCK(m_wallet.cs_wallet);
     m_wallet.AddDestData(dest, "misc", "val_misc");
     m_wallet.AddDestData(dest, "rr0", "val_rr0");
     m_wallet.AddDestData(dest, "rr1", "val_rr1");
 
     auto values = m_wallet.GetDestValues("rr");
     BOOST_CHECK_EQUAL(values.size(), 2U);
     BOOST_CHECK_EQUAL(values[0], "val_rr0");
     BOOST_CHECK_EQUAL(values[1], "val_rr1");
 }
 
 class ListCoinsTestingSetup : public TestChain100Setup {
 public:
     ListCoinsTestingSetup() {
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
         wallet = std::make_unique<CWallet>(Params(), *m_chain, WalletLocation(),
                                            WalletDatabase::CreateMock());
         bool firstRun;
         wallet->LoadWallet(firstRun);
         AddKey(*wallet, coinbaseKey);
         WalletRescanReserver reserver(wallet.get());
         reserver.reserve();
-        const CBlockIndex *const null_block = nullptr;
-        const CBlockIndex *stop_block = null_block + 1,
-                          *failed_block = null_block + 1;
-        BOOST_CHECK_EQUAL(wallet->ScanForWalletTransactions(
-                              ChainActive().Genesis(), nullptr, reserver,
-                              failed_block, stop_block),
-                          CWallet::ScanResult::SUCCESS);
-        BOOST_CHECK_EQUAL(stop_block, ChainActive().Tip());
-        BOOST_CHECK_EQUAL(failed_block, null_block);
+        CWallet::ScanResult result = wallet->ScanForWalletTransactions(
+            ::ChainActive().Genesis()->GetBlockHash(), BlockHash(), reserver,
+            false /* update */);
+        BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::SUCCESS);
+        BOOST_CHECK_EQUAL(result.stop_block,
+                          ::ChainActive().Tip()->GetBlockHash());
+        BOOST_CHECK_EQUAL(*result.stop_height, ::ChainActive().Height());
+        BOOST_CHECK(result.failed_block.IsNull());
     }
 
     ~ListCoinsTestingSetup() { wallet.reset(); }
 
     CWalletTx &AddTx(CRecipient recipient) {
         CTransactionRef tx;
         CReserveKey reservekey(wallet.get());
         Amount fee;
         int changePos = -1;
         std::string error;
         CCoinControl dummy;
         BOOST_CHECK(wallet->CreateTransaction(*m_locked_chain, {recipient}, tx,
                                               reservekey, fee, changePos, error,
                                               dummy));
         CValidationState state;
         BOOST_CHECK(
             wallet->CommitTransaction(tx, {}, {}, reservekey, nullptr, state));
         CMutableTransaction blocktx;
         {
             LOCK(wallet->cs_wallet);
             blocktx =
                 CMutableTransaction(*wallet->mapWallet.at(tx->GetId()).tx);
         }
         CreateAndProcessBlock({CMutableTransaction(blocktx)},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
         LOCK(wallet->cs_wallet);
         auto it = wallet->mapWallet.find(tx->GetId());
         BOOST_CHECK(it != wallet->mapWallet.end());
-        it->second.SetMerkleBranch(::ChainActive().Tip(), 1);
+        it->second.SetMerkleBranch(::ChainActive().Tip()->GetBlockHash(), 1);
         return it->second;
     }
 
     std::unique_ptr<interfaces::Chain> m_chain = interfaces::MakeChain();
     // Temporary. Removed in upcoming lock cleanup
     std::unique_ptr<interfaces::Chain::Lock> m_locked_chain =
         m_chain->assumeLocked();
     std::unique_ptr<CWallet> wallet;
 };
 
 BOOST_FIXTURE_TEST_CASE(ListCoins, ListCoinsTestingSetup) {
     std::string coinbaseAddress = coinbaseKey.GetPubKey().GetID().ToString();
 
     // Confirm ListCoins initially returns 1 coin grouped under coinbaseKey
     // address.
     std::map<CTxDestination, std::vector<COutput>> list;
     {
         LOCK2(cs_main, wallet->cs_wallet);
         list = wallet->ListCoins(*m_locked_chain);
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
     BOOST_CHECK_EQUAL(boost::get<CKeyID>(list.begin()->first).ToString(),
                       coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 1U);
 
     // Check initial balance from one mature coinbase transaction.
     BOOST_CHECK_EQUAL(50 * COIN, wallet->GetAvailableBalance());
 
     // Add a transaction creating a change address, and confirm ListCoins still
     // returns the coin associated with the change address underneath the
     // coinbaseKey pubkey, even though the change address has a different
     // pubkey.
     AddTx(CRecipient{GetScriptForRawPubKey({}), 1 * COIN,
                      false /* subtract fee */});
     {
         LOCK2(cs_main, wallet->cs_wallet);
         list = wallet->ListCoins(*m_locked_chain);
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
     BOOST_CHECK_EQUAL(boost::get<CKeyID>(list.begin()->first).ToString(),
                       coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 2U);
 
     // Lock both coins. Confirm number of available coins drops to 0.
     {
         LOCK2(cs_main, wallet->cs_wallet);
         std::vector<COutput> available;
         wallet->AvailableCoins(*m_locked_chain, available);
         BOOST_CHECK_EQUAL(available.size(), 2U);
     }
     for (const auto &group : list) {
         for (const auto &coin : group.second) {
             LOCK(wallet->cs_wallet);
             wallet->LockCoin(COutPoint(coin.tx->GetId(), coin.i));
         }
     }
     {
         LOCK2(cs_main, wallet->cs_wallet);
         std::vector<COutput> available;
         wallet->AvailableCoins(*m_locked_chain, available);
         BOOST_CHECK_EQUAL(available.size(), 0U);
     }
     // Confirm ListCoins still returns same result as before, despite coins
     // being locked.
     {
         LOCK2(cs_main, wallet->cs_wallet);
         list = wallet->ListCoins(*m_locked_chain);
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
     BOOST_CHECK_EQUAL(boost::get<CKeyID>(list.begin()->first).ToString(),
                       coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 2U);
 }
 
 BOOST_FIXTURE_TEST_CASE(wallet_disableprivkeys, TestChain100Setup) {
     auto chain = interfaces::MakeChain();
     std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
         Params(), *chain, WalletLocation(), WalletDatabase::CreateDummy());
     wallet->SetMinVersion(FEATURE_LATEST);
     wallet->SetWalletFlag(WALLET_FLAG_DISABLE_PRIVATE_KEYS);
     BOOST_CHECK(!wallet->TopUpKeyPool(1000));
     CPubKey pubkey;
     BOOST_CHECK(!wallet->GetKeyFromPool(pubkey, false));
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index da85bb85e6..aa1bf96ad8 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1,4955 +1,4963 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <wallet/wallet.h>
 
 #include <chain.h>
 #include <checkpoints.h>
 #include <config.h>
 #include <consensus/consensus.h>
 #include <consensus/validation.h>
 #include <fs.h>
 #include <interfaces/chain.h>
 #include <key.h>
 #include <key_io.h>
 #include <keystore.h>
 #include <net.h>
 #include <policy/mempool.h>
 #include <policy/policy.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <random.h>
 #include <script/script.h>
 #include <script/sighashtype.h>
 #include <script/sign.h>
 #include <shutdown.h>
 #include <timedata.h>
 #include <txmempool.h>
 #include <ui_interface.h>
 #include <util/moneystr.h>
 #include <util/system.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/coinselection.h>
 #include <wallet/fees.h>
 #include <wallet/finaltx.h>
 
 #include <boost/algorithm/string/replace.hpp>
 
 #include <algorithm>
 #include <cassert>
 #include <future>
 
 static CCriticalSection cs_wallets;
 static std::vector<std::shared_ptr<CWallet>> vpwallets GUARDED_BY(cs_wallets);
 
 bool AddWallet(const std::shared_ptr<CWallet> &wallet) {
     LOCK(cs_wallets);
     assert(wallet);
     std::vector<std::shared_ptr<CWallet>>::const_iterator i =
         std::find(vpwallets.begin(), vpwallets.end(), wallet);
     if (i != vpwallets.end()) {
         return false;
     }
     vpwallets.push_back(wallet);
     return true;
 }
 
 bool RemoveWallet(const std::shared_ptr<CWallet> &wallet) {
     LOCK(cs_wallets);
     assert(wallet);
     std::vector<std::shared_ptr<CWallet>>::iterator i =
         std::find(vpwallets.begin(), vpwallets.end(), wallet);
     if (i == vpwallets.end()) {
         return false;
     }
     vpwallets.erase(i);
     return true;
 }
 
 bool HasWallets() {
     LOCK(cs_wallets);
     return !vpwallets.empty();
 }
 
 std::vector<std::shared_ptr<CWallet>> GetWallets() {
     LOCK(cs_wallets);
     return vpwallets;
 }
 
 std::shared_ptr<CWallet> GetWallet(const std::string &name) {
     LOCK(cs_wallets);
     for (const std::shared_ptr<CWallet> &wallet : vpwallets) {
         if (wallet->GetName() == name) {
             return wallet;
         }
     }
     return nullptr;
 }
 
 static Mutex g_wallet_release_mutex;
 static std::condition_variable g_wallet_release_cv;
 static std::set<std::string> g_unloading_wallet_set;
 
 // Custom deleter for shared_ptr<CWallet>.
 static void ReleaseWallet(CWallet *wallet) {
     // Unregister and delete the wallet right after
     // BlockUntilSyncedToCurrentChain so that it's in sync with the current
     // chainstate.
     const std::string name = wallet->GetName();
     wallet->WalletLogPrintf("Releasing wallet\n");
     wallet->BlockUntilSyncedToCurrentChain();
     wallet->Flush();
     UnregisterValidationInterface(wallet);
     delete wallet;
     // Wallet is now released, notify UnloadWallet, if any.
     {
         LOCK(g_wallet_release_mutex);
         if (g_unloading_wallet_set.erase(name) == 0) {
             // UnloadWallet was not called for this wallet, all done.
             return;
         }
     }
     g_wallet_release_cv.notify_all();
 }
 
 void UnloadWallet(std::shared_ptr<CWallet> &&wallet) {
     // Mark wallet for unloading.
     const std::string name = wallet->GetName();
     {
         LOCK(g_wallet_release_mutex);
         auto it = g_unloading_wallet_set.insert(name);
         assert(it.second);
     }
     // The wallet can be in use so it's not possible to explicitly unload here.
     // Notify the unload intent so that all remaining shared pointers are
     // released.
     wallet->NotifyUnload();
     // Time to ditch our shared_ptr and wait for ReleaseWallet call.
     wallet.reset();
     {
         WAIT_LOCK(g_wallet_release_mutex, lock);
         while (g_unloading_wallet_set.count(name) == 1) {
             g_wallet_release_cv.wait(lock);
         }
     }
 }
 
 static const size_t OUTPUT_GROUP_MAX_ENTRIES = 10;
 
 const uint32_t BIP32_HARDENED_KEY_LIMIT = 0x80000000;
 
 const BlockHash CMerkleTx::ABANDON_HASH(uint256S(
     "0000000000000000000000000000000000000000000000000000000000000001"));
 
 /** @defgroup mapWallet
  *
  * @{
  */
 
 std::string COutput::ToString() const {
     return strprintf("COutput(%s, %d, %d) [%s]", tx->GetId().ToString(), i,
                      nDepth, FormatMoney(tx->tx->vout[i].nValue));
 }
 
 class CAffectedKeysVisitor : public boost::static_visitor<void> {
 private:
     const CKeyStore &keystore;
     std::vector<CKeyID> &vKeys;
 
 public:
     CAffectedKeysVisitor(const CKeyStore &keystoreIn,
                          std::vector<CKeyID> &vKeysIn)
         : keystore(keystoreIn), vKeys(vKeysIn) {}
 
     void Process(const CScript &script) {
         txnouttype type;
         std::vector<CTxDestination> vDest;
         int nRequired;
         if (ExtractDestinations(script, type, vDest, nRequired)) {
             for (const CTxDestination &dest : vDest) {
                 boost::apply_visitor(*this, dest);
             }
         }
     }
 
     void operator()(const CKeyID &keyId) {
         if (keystore.HaveKey(keyId)) {
             vKeys.push_back(keyId);
         }
     }
 
     void operator()(const CScriptID &scriptId) {
         CScript script;
         if (keystore.GetCScript(scriptId, script)) {
             Process(script);
         }
     }
 
     void operator()(const CNoDestination &none) {}
 };
 
 const CWalletTx *CWallet::GetWalletTx(const TxId &txid) const {
     LOCK(cs_wallet);
     std::map<TxId, CWalletTx>::const_iterator it = mapWallet.find(txid);
     if (it == mapWallet.end()) {
         return nullptr;
     }
 
     return &(it->second);
 }
 
 CPubKey CWallet::GenerateNewKey(WalletBatch &batch, bool internal) {
     assert(!IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
     assert(!IsWalletFlagSet(WALLET_FLAG_BLANK_WALLET));
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
     // default to compressed public keys if we want 0.6.0 wallets
     bool fCompressed = CanSupportFeature(FEATURE_COMPRPUBKEY);
 
     CKey secret;
 
     // Create new metadata
     int64_t nCreationTime = GetTime();
     CKeyMetadata metadata(nCreationTime);
 
     // use HD key derivation if HD was enabled during wallet creation and a seed
     // is present
     if (IsHDEnabled()) {
         DeriveNewChildKey(
             batch, metadata, secret,
             (CanSupportFeature(FEATURE_HD_SPLIT) ? internal : false));
     } else {
         secret.MakeNewKey(fCompressed);
     }
 
     // Compressed public keys were introduced in version 0.6.0
     if (fCompressed) {
         SetMinVersion(FEATURE_COMPRPUBKEY);
     }
 
     CPubKey pubkey = secret.GetPubKey();
     assert(secret.VerifyPubKey(pubkey));
 
     mapKeyMetadata[pubkey.GetID()] = metadata;
     UpdateTimeFirstKey(nCreationTime);
 
     if (!AddKeyPubKeyWithDB(batch, secret, pubkey)) {
         throw std::runtime_error(std::string(__func__) + ": AddKey failed");
     }
 
     return pubkey;
 }
 
 void CWallet::DeriveNewChildKey(WalletBatch &batch, CKeyMetadata &metadata,
                                 CKey &secret, bool internal) {
     // for now we use a fixed keypath scheme of m/0'/0'/k
     // seed (256bit)
     CKey seed;
     // hd master key
     CExtKey masterKey;
     // key at m/0'
     CExtKey accountKey;
     // key at m/0'/0' (external) or m/0'/1' (internal)
     CExtKey chainChildKey;
     // key at m/0'/0'/<n>'
     CExtKey childKey;
 
     // try to get the seed
     if (!GetKey(hdChain.seed_id, seed)) {
         throw std::runtime_error(std::string(__func__) + ": seed not found");
     }
 
     masterKey.SetSeed(seed.begin(), seed.size());
 
     // derive m/0'
     // use hardened derivation (child keys >= 0x80000000 are hardened after
     // bip32)
     masterKey.Derive(accountKey, BIP32_HARDENED_KEY_LIMIT);
 
     // derive m/0'/0' (external chain) OR m/0'/1' (internal chain)
     assert(internal ? CanSupportFeature(FEATURE_HD_SPLIT) : true);
     accountKey.Derive(chainChildKey,
                       BIP32_HARDENED_KEY_LIMIT + (internal ? 1 : 0));
 
     // derive child key at next index, skip keys already known to the wallet
     do {
         // always derive hardened keys
         // childIndex | BIP32_HARDENED_KEY_LIMIT = derive childIndex in hardened
         // child-index-range
         // example: 1 | BIP32_HARDENED_KEY_LIMIT == 0x80000001 == 2147483649
         if (internal) {
             chainChildKey.Derive(childKey, hdChain.nInternalChainCounter |
                                                BIP32_HARDENED_KEY_LIMIT);
             metadata.hdKeypath = "m/0'/1'/" +
                                  std::to_string(hdChain.nInternalChainCounter) +
                                  "'";
             hdChain.nInternalChainCounter++;
         } else {
             chainChildKey.Derive(childKey, hdChain.nExternalChainCounter |
                                                BIP32_HARDENED_KEY_LIMIT);
             metadata.hdKeypath = "m/0'/0'/" +
                                  std::to_string(hdChain.nExternalChainCounter) +
                                  "'";
             hdChain.nExternalChainCounter++;
         }
     } while (HaveKey(childKey.key.GetPubKey().GetID()));
     secret = childKey.key;
     metadata.hd_seed_id = hdChain.seed_id;
     // update the chain model in the database
     if (!batch.WriteHDChain(hdChain)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": Writing HD chain model failed");
     }
 }
 
 bool CWallet::AddKeyPubKeyWithDB(WalletBatch &batch, const CKey &secret,
                                  const CPubKey &pubkey) {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
 
     // Make sure we aren't adding private keys to private key disabled wallets
     assert(!IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
 
     // CCryptoKeyStore has no concept of wallet databases, but calls
     // AddCryptedKey which is overridden below. To avoid flushes, the database
     // handle is tunneled through to it.
     bool needsDB = !encrypted_batch;
     if (needsDB) {
         encrypted_batch = &batch;
     }
     if (!CCryptoKeyStore::AddKeyPubKey(secret, pubkey)) {
         if (needsDB) {
             encrypted_batch = nullptr;
         }
         return false;
     }
 
     if (needsDB) {
         encrypted_batch = nullptr;
     }
 
     // Check if we need to remove from watch-only.
     CScript script;
     script = GetScriptForDestination(pubkey.GetID());
     if (HaveWatchOnly(script)) {
         RemoveWatchOnly(script);
     }
 
     script = GetScriptForRawPubKey(pubkey);
     if (HaveWatchOnly(script)) {
         RemoveWatchOnly(script);
     }
 
     if (!IsCrypted()) {
         return batch.WriteKey(pubkey, secret.GetPrivKey(),
                               mapKeyMetadata[pubkey.GetID()]);
     }
 
     UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
     return true;
 }
 
 bool CWallet::AddKeyPubKey(const CKey &secret, const CPubKey &pubkey) {
     WalletBatch batch(*database);
     return CWallet::AddKeyPubKeyWithDB(batch, secret, pubkey);
 }
 
 bool CWallet::AddCryptedKey(const CPubKey &vchPubKey,
                             const std::vector<uint8_t> &vchCryptedSecret) {
     if (!CCryptoKeyStore::AddCryptedKey(vchPubKey, vchCryptedSecret)) {
         return false;
     }
 
     LOCK(cs_wallet);
     if (encrypted_batch) {
         return encrypted_batch->WriteCryptedKey(
             vchPubKey, vchCryptedSecret, mapKeyMetadata[vchPubKey.GetID()]);
     }
 
     return WalletBatch(*database).WriteCryptedKey(
         vchPubKey, vchCryptedSecret, mapKeyMetadata[vchPubKey.GetID()]);
 }
 
 void CWallet::LoadKeyMetadata(const CKeyID &keyID, const CKeyMetadata &meta) {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
     UpdateTimeFirstKey(meta.nCreateTime);
     mapKeyMetadata[keyID] = meta;
 }
 
 void CWallet::LoadScriptMetadata(const CScriptID &script_id,
                                  const CKeyMetadata &meta) {
     // m_script_metadata
     AssertLockHeld(cs_wallet);
     UpdateTimeFirstKey(meta.nCreateTime);
     m_script_metadata[script_id] = meta;
 }
 
 bool CWallet::LoadCryptedKey(const CPubKey &vchPubKey,
                              const std::vector<uint8_t> &vchCryptedSecret) {
     return CCryptoKeyStore::AddCryptedKey(vchPubKey, vchCryptedSecret);
 }
 
 /**
  * Update wallet first key creation time. This should be called whenever keys
  * are added to the wallet, with the oldest key creation time.
  */
 void CWallet::UpdateTimeFirstKey(int64_t nCreateTime) {
     AssertLockHeld(cs_wallet);
     if (nCreateTime <= 1) {
         // Cannot determine birthday information, so set the wallet birthday to
         // the beginning of time.
         nTimeFirstKey = 1;
     } else if (!nTimeFirstKey || nCreateTime < nTimeFirstKey) {
         nTimeFirstKey = nCreateTime;
     }
 }
 
 bool CWallet::AddCScript(const CScript &redeemScript) {
     if (!CCryptoKeyStore::AddCScript(redeemScript)) {
         return false;
     }
     if (WalletBatch(*database).WriteCScript(Hash160(redeemScript),
                                             redeemScript)) {
         UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
         return true;
     }
     return false;
 }
 
 bool CWallet::LoadCScript(const CScript &redeemScript) {
     /**
      * A sanity check was added in pull #3843 to avoid adding redeemScripts that
      * never can be redeemed. However, old wallets may still contain these. Do
      * not add them to the wallet and warn.
      */
     if (redeemScript.size() > MAX_SCRIPT_ELEMENT_SIZE) {
         std::string strAddr =
             EncodeDestination(CScriptID(redeemScript), GetConfig());
         WalletLogPrintf("%s: Warning: This wallet contains a redeemScript "
                         "of size %i which exceeds maximum size %i thus can "
                         "never be redeemed. Do not use address %s.\n",
                         __func__, redeemScript.size(), MAX_SCRIPT_ELEMENT_SIZE,
                         strAddr);
         return true;
     }
 
     return CCryptoKeyStore::AddCScript(redeemScript);
 }
 
 bool CWallet::AddWatchOnly(const CScript &dest) {
     if (!CCryptoKeyStore::AddWatchOnly(dest)) {
         return false;
     }
 
     const CKeyMetadata &meta = m_script_metadata[CScriptID(dest)];
     UpdateTimeFirstKey(meta.nCreateTime);
     NotifyWatchonlyChanged(true);
     if (WalletBatch(*database).WriteWatchOnly(dest, meta)) {
         UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
         return true;
     }
     return false;
 }
 
 bool CWallet::AddWatchOnly(const CScript &dest, int64_t nCreateTime) {
     m_script_metadata[CScriptID(dest)].nCreateTime = nCreateTime;
     return AddWatchOnly(dest);
 }
 
 bool CWallet::RemoveWatchOnly(const CScript &dest) {
     AssertLockHeld(cs_wallet);
     if (!CCryptoKeyStore::RemoveWatchOnly(dest)) {
         return false;
     }
 
     if (!HaveWatchOnly()) {
         NotifyWatchonlyChanged(false);
     }
 
     return WalletBatch(*database).EraseWatchOnly(dest);
 }
 
 bool CWallet::LoadWatchOnly(const CScript &dest) {
     return CCryptoKeyStore::AddWatchOnly(dest);
 }
 
 bool CWallet::Unlock(const SecureString &strWalletPassphrase) {
     CCrypter crypter;
     CKeyingMaterial _vMasterKey;
 
     LOCK(cs_wallet);
     for (const MasterKeyMap::value_type &pMasterKey : mapMasterKeys) {
         if (!crypter.SetKeyFromPassphrase(
                 strWalletPassphrase, pMasterKey.second.vchSalt,
                 pMasterKey.second.nDeriveIterations,
                 pMasterKey.second.nDerivationMethod)) {
             return false;
         }
 
         if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey, _vMasterKey)) {
             // try another master key
             continue;
         }
 
         if (CCryptoKeyStore::Unlock(_vMasterKey)) {
             return true;
         }
     }
 
     return false;
 }
 
 bool CWallet::ChangeWalletPassphrase(
     const SecureString &strOldWalletPassphrase,
     const SecureString &strNewWalletPassphrase) {
     bool fWasLocked = IsLocked();
 
     LOCK(cs_wallet);
     Lock();
 
     CCrypter crypter;
     CKeyingMaterial _vMasterKey;
     for (MasterKeyMap::value_type &pMasterKey : mapMasterKeys) {
         if (!crypter.SetKeyFromPassphrase(
                 strOldWalletPassphrase, pMasterKey.second.vchSalt,
                 pMasterKey.second.nDeriveIterations,
                 pMasterKey.second.nDerivationMethod)) {
             return false;
         }
 
         if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey, _vMasterKey)) {
             return false;
         }
 
         if (CCryptoKeyStore::Unlock(_vMasterKey)) {
             int64_t nStartTime = GetTimeMillis();
             crypter.SetKeyFromPassphrase(strNewWalletPassphrase,
                                          pMasterKey.second.vchSalt,
                                          pMasterKey.second.nDeriveIterations,
                                          pMasterKey.second.nDerivationMethod);
             pMasterKey.second.nDeriveIterations = static_cast<unsigned int>(
                 pMasterKey.second.nDeriveIterations *
                 (100 / ((double)(GetTimeMillis() - nStartTime))));
 
             nStartTime = GetTimeMillis();
             crypter.SetKeyFromPassphrase(strNewWalletPassphrase,
                                          pMasterKey.second.vchSalt,
                                          pMasterKey.second.nDeriveIterations,
                                          pMasterKey.second.nDerivationMethod);
             pMasterKey.second.nDeriveIterations =
                 (pMasterKey.second.nDeriveIterations +
                  static_cast<unsigned int>(
                      pMasterKey.second.nDeriveIterations * 100 /
                      double(GetTimeMillis() - nStartTime))) /
                 2;
 
             if (pMasterKey.second.nDeriveIterations < 25000) {
                 pMasterKey.second.nDeriveIterations = 25000;
             }
 
             WalletLogPrintf(
                 "Wallet passphrase changed to an nDeriveIterations of %i\n",
                 pMasterKey.second.nDeriveIterations);
 
             if (!crypter.SetKeyFromPassphrase(
                     strNewWalletPassphrase, pMasterKey.second.vchSalt,
                     pMasterKey.second.nDeriveIterations,
                     pMasterKey.second.nDerivationMethod)) {
                 return false;
             }
 
             if (!crypter.Encrypt(_vMasterKey,
                                  pMasterKey.second.vchCryptedKey)) {
                 return false;
             }
 
             WalletBatch(*database).WriteMasterKey(pMasterKey.first,
                                                   pMasterKey.second);
             if (fWasLocked) {
                 Lock();
             }
 
             return true;
         }
     }
 
     return false;
 }
 
 void CWallet::ChainStateFlushed(const CBlockLocator &loc) {
     WalletBatch batch(*database);
     batch.WriteBestBlock(loc);
 }
 
 void CWallet::SetMinVersion(enum WalletFeature nVersion, WalletBatch *batch_in,
                             bool fExplicit) {
     // nWalletVersion
     LOCK(cs_wallet);
     if (nWalletVersion >= nVersion) {
         return;
     }
 
     // When doing an explicit upgrade, if we pass the max version permitted,
     // upgrade all the way.
     if (fExplicit && nVersion > nWalletMaxVersion) {
         nVersion = FEATURE_LATEST;
     }
 
     nWalletVersion = nVersion;
 
     if (nVersion > nWalletMaxVersion) {
         nWalletMaxVersion = nVersion;
     }
 
     WalletBatch *batch = batch_in ? batch_in : new WalletBatch(*database);
     if (nWalletVersion > 40000) {
         batch->WriteMinVersion(nWalletVersion);
     }
     if (!batch_in) {
         delete batch;
     }
 }
 
 bool CWallet::SetMaxVersion(int nVersion) {
     // nWalletVersion, nWalletMaxVersion
     LOCK(cs_wallet);
 
     // Cannot downgrade below current version
     if (nWalletVersion > nVersion) {
         return false;
     }
 
     nWalletMaxVersion = nVersion;
 
     return true;
 }
 
 std::set<TxId> CWallet::GetConflicts(const TxId &txid) const {
     std::set<TxId> result;
     AssertLockHeld(cs_wallet);
 
     std::map<TxId, CWalletTx>::const_iterator it = mapWallet.find(txid);
     if (it == mapWallet.end()) {
         return result;
     }
 
     const CWalletTx &wtx = it->second;
 
     std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range;
 
     for (const CTxIn &txin : wtx.tx->vin) {
         if (mapTxSpends.count(txin.prevout) <= 1) {
             // No conflict if zero or one spends.
             continue;
         }
 
         range = mapTxSpends.equal_range(txin.prevout);
         for (TxSpends::const_iterator _it = range.first; _it != range.second;
              ++_it) {
             result.insert(_it->second);
         }
     }
 
     return result;
 }
 
 bool CWallet::HasWalletSpend(const TxId &txid) const {
     AssertLockHeld(cs_wallet);
     auto iter = mapTxSpends.lower_bound(COutPoint(txid, 0));
     return (iter != mapTxSpends.end() && iter->first.GetTxId() == txid);
 }
 
 void CWallet::Flush(bool shutdown) {
     database->Flush(shutdown);
 }
 
 void CWallet::SyncMetaData(
     std::pair<TxSpends::iterator, TxSpends::iterator> range) {
     // We want all the wallet transactions in range to have the same metadata as
     // the oldest (smallest nOrderPos).
     // So: find smallest nOrderPos:
 
     int nMinOrderPos = std::numeric_limits<int>::max();
     const CWalletTx *copyFrom = nullptr;
     for (TxSpends::iterator it = range.first; it != range.second; ++it) {
         const CWalletTx *wtx = &mapWallet.at(it->second);
         if (wtx->nOrderPos < nMinOrderPos) {
             nMinOrderPos = wtx->nOrderPos;
             copyFrom = wtx;
         }
     }
 
     if (!copyFrom) {
         return;
     }
 
     // Now copy data from copyFrom to rest:
     for (TxSpends::iterator it = range.first; it != range.second; ++it) {
         const TxId &txid = it->second;
         CWalletTx *copyTo = &mapWallet.at(txid);
         if (copyFrom == copyTo) {
             continue;
         }
 
         assert(
             copyFrom &&
             "Oldest wallet transaction in range assumed to have been found.");
 
         if (!copyFrom->IsEquivalentTo(*copyTo)) {
             continue;
         }
 
         copyTo->mapValue = copyFrom->mapValue;
         copyTo->vOrderForm = copyFrom->vOrderForm;
         // fTimeReceivedIsTxTime not copied on purpose nTimeReceived not copied
         // on purpose.
         copyTo->nTimeSmart = copyFrom->nTimeSmart;
         copyTo->fFromMe = copyFrom->fFromMe;
         // nOrderPos not copied on purpose cached members not copied on purpose.
     }
 }
 
 /**
  * Outpoint is spent if any non-conflicted transaction, spends it:
  */
 bool CWallet::IsSpent(interfaces::Chain::Lock &locked_chain,
                       const COutPoint &outpoint) const {
     std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range =
         mapTxSpends.equal_range(outpoint);
 
     for (TxSpends::const_iterator it = range.first; it != range.second; ++it) {
         const TxId &wtxid = it->second;
         std::map<TxId, CWalletTx>::const_iterator mit = mapWallet.find(wtxid);
         if (mit != mapWallet.end()) {
             int depth = mit->second.GetDepthInMainChain(locked_chain);
             if (depth > 0 || (depth == 0 && !mit->second.isAbandoned())) {
                 // Spent
                 return true;
             }
         }
     }
 
     return false;
 }
 
 void CWallet::AddToSpends(const COutPoint &outpoint, const TxId &wtxid) {
     mapTxSpends.insert(std::make_pair(outpoint, wtxid));
 
     std::pair<TxSpends::iterator, TxSpends::iterator> range;
     range = mapTxSpends.equal_range(outpoint);
     SyncMetaData(range);
 }
 
 void CWallet::AddToSpends(const TxId &wtxid) {
     auto it = mapWallet.find(wtxid);
     assert(it != mapWallet.end());
     CWalletTx &thisTx = it->second;
     // Coinbases don't spend anything!
     if (thisTx.IsCoinBase()) {
         return;
     }
 
     for (const CTxIn &txin : thisTx.tx->vin) {
         AddToSpends(txin.prevout, wtxid);
     }
 }
 
 bool CWallet::EncryptWallet(const SecureString &strWalletPassphrase) {
     if (IsCrypted()) {
         return false;
     }
 
     CKeyingMaterial _vMasterKey;
 
     _vMasterKey.resize(WALLET_CRYPTO_KEY_SIZE);
     GetStrongRandBytes(&_vMasterKey[0], WALLET_CRYPTO_KEY_SIZE);
 
     CMasterKey kMasterKey;
 
     kMasterKey.vchSalt.resize(WALLET_CRYPTO_SALT_SIZE);
     GetStrongRandBytes(&kMasterKey.vchSalt[0], WALLET_CRYPTO_SALT_SIZE);
 
     CCrypter crypter;
     int64_t nStartTime = GetTimeMillis();
     crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt, 25000,
                                  kMasterKey.nDerivationMethod);
     kMasterKey.nDeriveIterations = static_cast<unsigned int>(
         2500000 / double(GetTimeMillis() - nStartTime));
 
     nStartTime = GetTimeMillis();
     crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt,
                                  kMasterKey.nDeriveIterations,
                                  kMasterKey.nDerivationMethod);
     kMasterKey.nDeriveIterations =
         (kMasterKey.nDeriveIterations +
          static_cast<unsigned int>(kMasterKey.nDeriveIterations * 100 /
                                    double(GetTimeMillis() - nStartTime))) /
         2;
 
     if (kMasterKey.nDeriveIterations < 25000) {
         kMasterKey.nDeriveIterations = 25000;
     }
 
     WalletLogPrintf("Encrypting Wallet with an nDeriveIterations of %i\n",
                     kMasterKey.nDeriveIterations);
 
     if (!crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt,
                                       kMasterKey.nDeriveIterations,
                                       kMasterKey.nDerivationMethod)) {
         return false;
     }
 
     if (!crypter.Encrypt(_vMasterKey, kMasterKey.vchCryptedKey)) {
         return false;
     }
 
     {
         LOCK(cs_wallet);
         mapMasterKeys[++nMasterKeyMaxID] = kMasterKey;
         assert(!encrypted_batch);
         encrypted_batch = new WalletBatch(*database);
         if (!encrypted_batch->TxnBegin()) {
             delete encrypted_batch;
             encrypted_batch = nullptr;
             return false;
         }
         encrypted_batch->WriteMasterKey(nMasterKeyMaxID, kMasterKey);
 
         if (!EncryptKeys(_vMasterKey)) {
             encrypted_batch->TxnAbort();
             delete encrypted_batch;
             // We now probably have half of our keys encrypted in memory, and
             // half not... die and let the user reload the unencrypted wallet.
             assert(false);
         }
 
         // Encryption was introduced in version 0.4.0
         SetMinVersion(FEATURE_WALLETCRYPT, encrypted_batch, true);
 
         if (!encrypted_batch->TxnCommit()) {
             delete encrypted_batch;
             // We now have keys encrypted in memory, but not on disk...
             // die to avoid confusion and let the user reload the unencrypted
             // wallet.
             assert(false);
         }
 
         delete encrypted_batch;
         encrypted_batch = nullptr;
 
         Lock();
         Unlock(strWalletPassphrase);
 
         // If we are using HD, replace the HD seed with a new one
         if (IsHDEnabled()) {
             SetHDSeed(GenerateNewSeed());
         }
 
         NewKeyPool();
         Lock();
 
         // Need to completely rewrite the wallet file; if we don't, bdb might
         // keep bits of the unencrypted private key in slack space in the
         // database file.
         database->Rewrite();
 
         // BDB seems to have a bad habit of writing old data into
         // slack space in .dat files; that is bad if the old data is
         // unencrypted private keys. So:
         database->ReloadDbEnv();
     }
 
     NotifyStatusChanged(this);
     return true;
 }
 
 DBErrors CWallet::ReorderTransactions() {
     LOCK(cs_wallet);
     WalletBatch batch(*database);
 
     // Old wallets didn't have any defined order for transactions. Probably a
     // bad idea to change the output of this.
 
     // First: get all CWalletTx into a sorted-by-time
     // multimap.
     TxItems txByTime;
 
     for (auto &entry : mapWallet) {
         CWalletTx *wtx = &entry.second;
         txByTime.insert(std::make_pair(wtx->nTimeReceived, wtx));
     }
 
     nOrderPosNext = 0;
     std::vector<int64_t> nOrderPosOffsets;
     for (TxItems::iterator it = txByTime.begin(); it != txByTime.end(); ++it) {
         CWalletTx *const pwtx = (*it).second;
         int64_t &nOrderPos = pwtx->nOrderPos;
 
         if (nOrderPos == -1) {
             nOrderPos = nOrderPosNext++;
             nOrderPosOffsets.push_back(nOrderPos);
 
             if (!batch.WriteTx(*pwtx)) {
                 return DBErrors::LOAD_FAIL;
             }
         } else {
             int64_t nOrderPosOff = 0;
             for (const int64_t &nOffsetStart : nOrderPosOffsets) {
                 if (nOrderPos >= nOffsetStart) {
                     ++nOrderPosOff;
                 }
             }
 
             nOrderPos += nOrderPosOff;
             nOrderPosNext = std::max(nOrderPosNext, nOrderPos + 1);
 
             if (!nOrderPosOff) {
                 continue;
             }
 
             // Since we're changing the order, write it back.
             if (!batch.WriteTx(*pwtx)) {
                 return DBErrors::LOAD_FAIL;
             }
         }
     }
 
     batch.WriteOrderPosNext(nOrderPosNext);
 
     return DBErrors::LOAD_OK;
 }
 
 int64_t CWallet::IncOrderPosNext(WalletBatch *batch) {
     // nOrderPosNext
     AssertLockHeld(cs_wallet);
     int64_t nRet = nOrderPosNext++;
     if (batch) {
         batch->WriteOrderPosNext(nOrderPosNext);
     } else {
         WalletBatch(*database).WriteOrderPosNext(nOrderPosNext);
     }
 
     return nRet;
 }
 
 void CWallet::MarkDirty() {
     LOCK(cs_wallet);
     for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
         item.second.MarkDirty();
     }
 }
 
 bool CWallet::AddToWallet(const CWalletTx &wtxIn, bool fFlushOnClose) {
     LOCK(cs_wallet);
 
     WalletBatch batch(*database, "r+", fFlushOnClose);
 
     const TxId &txid = wtxIn.GetId();
 
     // Inserts only if not already there, returns tx inserted or tx found.
     std::pair<std::map<TxId, CWalletTx>::iterator, bool> ret =
         mapWallet.insert(std::make_pair(txid, wtxIn));
     CWalletTx &wtx = (*ret.first).second;
     wtx.BindWallet(this);
     bool fInsertedNew = ret.second;
     if (fInsertedNew) {
         wtx.nTimeReceived = GetAdjustedTime();
         wtx.nOrderPos = IncOrderPosNext(&batch);
         wtx.m_it_wtxOrdered =
             wtxOrdered.insert(std::make_pair(wtx.nOrderPos, &wtx));
         wtx.nTimeSmart = ComputeTimeSmart(wtx);
         AddToSpends(txid);
     }
 
     bool fUpdated = false;
     if (!fInsertedNew) {
         // Merge
         if (!wtxIn.hashUnset() && wtxIn.hashBlock != wtx.hashBlock) {
             wtx.hashBlock = wtxIn.hashBlock;
             fUpdated = true;
         }
 
         // If no longer abandoned, update
         if (wtxIn.hashBlock.IsNull() && wtx.isAbandoned()) {
             wtx.hashBlock = wtxIn.hashBlock;
             fUpdated = true;
         }
 
         if (wtxIn.nIndex != -1 && (wtxIn.nIndex != wtx.nIndex)) {
             wtx.nIndex = wtxIn.nIndex;
             fUpdated = true;
         }
 
         if (wtxIn.fFromMe && wtxIn.fFromMe != wtx.fFromMe) {
             wtx.fFromMe = wtxIn.fFromMe;
             fUpdated = true;
         }
     }
 
     //// debug print
     WalletLogPrintf("AddToWallet %s  %s%s\n", wtxIn.GetId().ToString(),
                     (fInsertedNew ? "new" : ""), (fUpdated ? "update" : ""));
 
     // Write to disk
     if ((fInsertedNew || fUpdated) && !batch.WriteTx(wtx)) {
         return false;
     }
 
     // Break debit/credit balance caches:
     wtx.MarkDirty();
 
     // Notify UI of new or updated transaction.
     NotifyTransactionChanged(this, txid, fInsertedNew ? CT_NEW : CT_UPDATED);
 
     // Notify an external script when a wallet transaction comes in or is
     // updated.
     std::string strCmd = gArgs.GetArg("-walletnotify", "");
 
     if (!strCmd.empty()) {
         boost::replace_all(strCmd, "%s", wtxIn.GetId().GetHex());
         std::thread t(runCommand, strCmd);
         // Thread runs free.
         t.detach();
     }
 
     return true;
 }
 
 void CWallet::LoadToWallet(const CWalletTx &wtxIn) {
     const TxId &txid = wtxIn.GetId();
     const auto &ins = mapWallet.emplace(txid, wtxIn);
     CWalletTx &wtx = ins.first->second;
     wtx.BindWallet(this);
     if (/* insertion took place */ ins.second) {
         wtx.m_it_wtxOrdered =
             wtxOrdered.insert(std::make_pair(wtx.nOrderPos, &wtx));
     }
     AddToSpends(txid);
     for (const CTxIn &txin : wtx.tx->vin) {
         auto it = mapWallet.find(txin.prevout.GetTxId());
         if (it != mapWallet.end()) {
             CWalletTx &prevtx = it->second;
             if (prevtx.nIndex == -1 && !prevtx.hashUnset()) {
                 MarkConflicted(prevtx.hashBlock, wtx.GetId());
             }
         }
     }
 }
 
 bool CWallet::AddToWalletIfInvolvingMe(const CTransactionRef &ptx,
-                                       const CBlockIndex *pIndex,
+                                       const BlockHash &block_hash,
                                        int posInBlock, bool fUpdate) {
     const CTransaction &tx = *ptx;
     AssertLockHeld(cs_wallet);
 
-    if (pIndex != nullptr) {
+    if (!block_hash.IsNull()) {
         for (const CTxIn &txin : tx.vin) {
             std::pair<TxSpends::const_iterator, TxSpends::const_iterator>
                 range = mapTxSpends.equal_range(txin.prevout);
             while (range.first != range.second) {
                 if (range.first->second != tx.GetId()) {
                     WalletLogPrintf(
                         "Transaction %s (in block %s) conflicts with wallet "
                         "transaction %s (both spend %s:%i)\n",
-                        tx.GetId().ToString(),
-                        pIndex->GetBlockHash().ToString(),
+                        tx.GetId().ToString(), block_hash.ToString(),
                         range.first->second.ToString(),
                         range.first->first.GetTxId().ToString(),
                         range.first->first.GetN());
-                    MarkConflicted(pIndex->GetBlockHash(), range.first->second);
+                    MarkConflicted(block_hash, range.first->second);
                 }
                 range.first++;
             }
         }
     }
 
     bool fExisted = mapWallet.count(tx.GetId()) != 0;
     if (fExisted && !fUpdate) {
         return false;
     }
     if (fExisted || IsMine(tx) || IsFromMe(tx)) {
         /**
          * Check if any keys in the wallet keypool that were supposed to be
          * unused have appeared in a new transaction. If so, remove those keys
          * from the keypool. This can happen when restoring an old wallet backup
          * that does not contain the mostly recently created transactions from
          * newer versions of the wallet.
          */
 
         // loop though all outputs
         for (const CTxOut &txout : tx.vout) {
             // extract addresses and check if they match with an unused keypool
             // key
             std::vector<CKeyID> vAffected;
             CAffectedKeysVisitor(*this, vAffected).Process(txout.scriptPubKey);
             for (const CKeyID &keyid : vAffected) {
                 std::map<CKeyID, int64_t>::const_iterator mi =
                     m_pool_key_to_index.find(keyid);
                 if (mi != m_pool_key_to_index.end()) {
                     WalletLogPrintf("%s: Detected a used keypool key, mark all "
                                     "keypool key up to this key as used\n",
                                     __func__);
                     MarkReserveKeysAsUsed(mi->second);
 
                     if (!TopUpKeyPool()) {
                         WalletLogPrintf(
                             "%s: Topping up keypool failed (locked wallet)\n",
                             __func__);
                     }
                 }
             }
         }
 
         CWalletTx wtx(this, ptx);
 
         // Get merkle branch if transaction was found in a block
-        if (pIndex != nullptr) {
-            wtx.SetMerkleBranch(pIndex, posInBlock);
+        if (!block_hash.IsNull()) {
+            wtx.SetMerkleBranch(block_hash, posInBlock);
         }
 
         return AddToWallet(wtx, false);
     }
 
     return false;
 }
 
 bool CWallet::TransactionCanBeAbandoned(const TxId &txid) const {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
     const CWalletTx *wtx = GetWalletTx(txid);
     return wtx && !wtx->isAbandoned() &&
            wtx->GetDepthInMainChain(*locked_chain) == 0 && !wtx->InMempool();
 }
 
 void CWallet::MarkInputsDirty(const CTransactionRef &tx) {
     for (const CTxIn &txin : tx->vin) {
         auto it = mapWallet.find(txin.prevout.GetTxId());
         if (it != mapWallet.end()) {
             it->second.MarkDirty();
         }
     }
 }
 
 bool CWallet::AbandonTransaction(interfaces::Chain::Lock &locked_chain,
                                  const TxId &txid) {
     // Temporary. Removed in upcoming lock cleanup
     auto locked_chain_recursive = chain().lock();
     LOCK(cs_wallet);
 
     WalletBatch batch(*database, "r+");
 
     std::set<TxId> todo;
     std::set<TxId> done;
 
     // Can't mark abandoned if confirmed or in mempool
     auto it = mapWallet.find(txid);
     assert(it != mapWallet.end());
     CWalletTx &origtx = it->second;
     if (origtx.GetDepthInMainChain(locked_chain) != 0 || origtx.InMempool()) {
         return false;
     }
 
     todo.insert(txid);
 
     while (!todo.empty()) {
         const TxId now = *todo.begin();
         todo.erase(now);
         done.insert(now);
         it = mapWallet.find(now);
         assert(it != mapWallet.end());
         CWalletTx &wtx = it->second;
         int currentconfirm = wtx.GetDepthInMainChain(locked_chain);
         // If the orig tx was not in block, none of its spends can be.
         assert(currentconfirm <= 0);
         // If (currentconfirm < 0) {Tx and spends are already conflicted, no
         // need to abandon}
         if (currentconfirm == 0 && !wtx.isAbandoned()) {
             // If the orig tx was not in block/mempool, none of its spends can
             // be in mempool.
             assert(!wtx.InMempool());
             wtx.nIndex = -1;
             wtx.setAbandoned();
             wtx.MarkDirty();
             batch.WriteTx(wtx);
             NotifyTransactionChanged(this, wtx.GetId(), CT_UPDATED);
             // Iterate over all its outputs, and mark transactions in the wallet
             // that spend them abandoned too.
             TxSpends::const_iterator iter =
                 mapTxSpends.lower_bound(COutPoint(now, 0));
             while (iter != mapTxSpends.end() && iter->first.GetTxId() == now) {
                 if (!done.count(iter->second)) {
                     todo.insert(iter->second);
                 }
                 iter++;
             }
 
             // If a transaction changes 'conflicted' state, that changes the
             // balance available of the outputs it spends. So force those to be
             // recomputed.
             MarkInputsDirty(wtx.tx);
         }
     }
 
     return true;
 }
 
 void CWallet::MarkConflicted(const BlockHash &hashBlock, const TxId &txid) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
-    int conflictconfirms = 0;
-    CBlockIndex *pindex = LookupBlockIndex(hashBlock);
-    if (pindex && ::ChainActive().Contains(pindex)) {
-        conflictconfirms = -(::ChainActive().Height() - pindex->nHeight + 1);
-    }
+    int conflictconfirms = -locked_chain->getBlockDepth(hashBlock);
 
     // If number of conflict confirms cannot be determined, this means that the
     // block is still unknown or not yet part of the main chain, for example
     // when loading the wallet during a reindex. Do nothing in that case.
     if (conflictconfirms >= 0) {
         return;
     }
 
     // Do not flush the wallet here for performance reasons.
     WalletBatch batch(*database, "r+", false);
 
     std::set<TxId> todo;
     std::set<TxId> done;
 
     todo.insert(txid);
 
     while (!todo.empty()) {
         const TxId now = *todo.begin();
         todo.erase(now);
         done.insert(now);
         auto it = mapWallet.find(now);
         assert(it != mapWallet.end());
         CWalletTx &wtx = it->second;
         int currentconfirm = wtx.GetDepthInMainChain(*locked_chain);
         if (conflictconfirms < currentconfirm) {
             // Block is 'more conflicted' than current confirm; update.
             // Mark transaction as conflicted with this block.
             wtx.nIndex = -1;
             wtx.hashBlock = hashBlock;
             wtx.MarkDirty();
             batch.WriteTx(wtx);
             // Iterate over all its outputs, and mark transactions in the wallet
             // that spend them conflicted too.
             TxSpends::const_iterator iter =
                 mapTxSpends.lower_bound(COutPoint(now, 0));
             while (iter != mapTxSpends.end() && iter->first.GetTxId() == now) {
                 if (!done.count(iter->second)) {
                     todo.insert(iter->second);
                 }
                 iter++;
             }
             // If a transaction changes 'conflicted' state, that changes the
             // balance available of the outputs it spends. So force those to be
             // recomputed.
             MarkInputsDirty(wtx.tx);
         }
     }
 }
 
 void CWallet::SyncTransaction(const CTransactionRef &ptx,
-                              const CBlockIndex *pindex, int posInBlock,
+                              const BlockHash &block_hash, int posInBlock,
                               bool update_tx) {
-    if (!AddToWalletIfInvolvingMe(ptx, pindex, posInBlock, update_tx)) {
+    if (!AddToWalletIfInvolvingMe(ptx, block_hash, posInBlock, update_tx)) {
         // Not one of ours
         return;
     }
 
     // If a transaction changes 'conflicted' state, that changes the balance
     // available of the outputs it spends. So force those to be
     // recomputed, also:
     MarkInputsDirty(ptx);
 }
 
 void CWallet::TransactionAddedToMempool(const CTransactionRef &ptx) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
-    SyncTransaction(ptx);
+    SyncTransaction(ptx, BlockHash(), 0 /* position in block */);
 
     auto it = mapWallet.find(ptx->GetId());
     if (it != mapWallet.end()) {
         it->second.fInMempool = true;
     }
 }
 
 void CWallet::TransactionRemovedFromMempool(const CTransactionRef &ptx) {
     LOCK(cs_wallet);
     auto it = mapWallet.find(ptx->GetId());
     if (it != mapWallet.end()) {
         it->second.fInMempool = false;
     }
 }
 
 void CWallet::BlockConnected(
     const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex,
     const std::vector<CTransactionRef> &vtxConflicted) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     // TODO: Temporarily ensure that mempool removals are notified before
     // connected transactions. This shouldn't matter, but the abandoned state of
     // transactions in our wallet is currently cleared when we receive another
     // notification and there is a race condition where notification of a
     // connected conflict might cause an outside process to abandon a
     // transaction and then have it inadvertently cleared by the notification
     // that the conflicted transaction was evicted.
     for (const CTransactionRef &ptx : vtxConflicted) {
-        SyncTransaction(ptx);
+        SyncTransaction(ptx, BlockHash(), 0 /* position in block */);
         TransactionRemovedFromMempool(ptx);
     }
 
     for (size_t i = 0; i < pblock->vtx.size(); i++) {
-        SyncTransaction(pblock->vtx[i], pindex, i);
+        SyncTransaction(pblock->vtx[i], pindex->GetBlockHash(), i);
         TransactionRemovedFromMempool(pblock->vtx[i]);
     }
 
-    m_last_block_processed = pindex;
+    m_last_block_processed = pindex->GetBlockHash();
 }
 
 void CWallet::BlockDisconnected(const std::shared_ptr<const CBlock> &pblock) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     for (const CTransactionRef &ptx : pblock->vtx) {
-        SyncTransaction(ptx);
+        SyncTransaction(ptx, BlockHash(), 0 /* position in block */);
     }
 }
 
 void CWallet::BlockUntilSyncedToCurrentChain() {
     AssertLockNotHeld(cs_main);
     AssertLockNotHeld(cs_wallet);
 
     {
         // Skip the queue-draining stuff if we know we're caught up with
         // ::ChainActive().Tip()...
         // We could also take cs_wallet here, and call m_last_block_processed
         // protected by cs_wallet instead of cs_main, but as long as we need
         // cs_main here anyway, it's easier to just call it cs_main-protected.
         auto locked_chain = chain().lock();
-        const CBlockIndex *initialChainTip = ::ChainActive().Tip();
-        if (m_last_block_processed &&
-            m_last_block_processed->GetAncestor(initialChainTip->nHeight) ==
-                initialChainTip) {
+        if (!m_last_block_processed.IsNull() &&
+            locked_chain->isPotentialTip(m_last_block_processed)) {
             return;
         }
     }
 
     // ...otherwise put a callback in the validation interface queue and wait
     // for the queue to drain enough to execute it (indicating we are caught up
     // at least with the time we entered this function).
     SyncWithValidationInterfaceQueue();
 }
 
 isminetype CWallet::IsMine(const CTxIn &txin) const {
     LOCK(cs_wallet);
     std::map<TxId, CWalletTx>::const_iterator mi =
         mapWallet.find(txin.prevout.GetTxId());
     if (mi != mapWallet.end()) {
         const CWalletTx &prev = (*mi).second;
         if (txin.prevout.GetN() < prev.tx->vout.size()) {
             return IsMine(prev.tx->vout[txin.prevout.GetN()]);
         }
     }
 
     return ISMINE_NO;
 }
 
 // Note that this function doesn't distinguish between a 0-valued input, and a
 // not-"is mine" (according to the filter) input.
 Amount CWallet::GetDebit(const CTxIn &txin, const isminefilter &filter) const {
     LOCK(cs_wallet);
     std::map<TxId, CWalletTx>::const_iterator mi =
         mapWallet.find(txin.prevout.GetTxId());
     if (mi != mapWallet.end()) {
         const CWalletTx &prev = (*mi).second;
         if (txin.prevout.GetN() < prev.tx->vout.size()) {
             if (IsMine(prev.tx->vout[txin.prevout.GetN()]) & filter) {
                 return prev.tx->vout[txin.prevout.GetN()].nValue;
             }
         }
     }
 
     return Amount::zero();
 }
 
 isminetype CWallet::IsMine(const CTxOut &txout) const {
     return ::IsMine(*this, txout.scriptPubKey);
 }
 
 Amount CWallet::GetCredit(const CTxOut &txout,
                           const isminefilter &filter) const {
     if (!MoneyRange(txout.nValue)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": value out of range");
     }
 
     return (IsMine(txout) & filter) ? txout.nValue : Amount::zero();
 }
 
 bool CWallet::IsChange(const CTxOut &txout) const {
     return IsChange(txout.scriptPubKey);
 }
 
 bool CWallet::IsChange(const CScript &script) const {
     // TODO: fix handling of 'change' outputs. The assumption is that any
     // payment to a script that is ours, but is not in the address book is
     // change. That assumption is likely to break when we implement
     // multisignature wallets that return change back into a
     // multi-signature-protected address; a better way of identifying which
     // outputs are 'the send' and which are 'the change' will need to be
     // implemented (maybe extend CWalletTx to remember which output, if any, was
     // change).
     if (::IsMine(*this, script)) {
         CTxDestination address;
         if (!ExtractDestination(script, address)) {
             return true;
         }
 
         LOCK(cs_wallet);
         if (!mapAddressBook.count(address)) {
             return true;
         }
     }
 
     return false;
 }
 
 Amount CWallet::GetChange(const CTxOut &txout) const {
     if (!MoneyRange(txout.nValue)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": value out of range");
     }
 
     return (IsChange(txout) ? txout.nValue : Amount::zero());
 }
 
 bool CWallet::IsMine(const CTransaction &tx) const {
     for (const CTxOut &txout : tx.vout) {
         if (IsMine(txout)) {
             return true;
         }
     }
 
     return false;
 }
 
 bool CWallet::IsFromMe(const CTransaction &tx) const {
     return GetDebit(tx, ISMINE_ALL) > Amount::zero();
 }
 
 Amount CWallet::GetDebit(const CTransaction &tx,
                          const isminefilter &filter) const {
     Amount nDebit = Amount::zero();
     for (const CTxIn &txin : tx.vin) {
         nDebit += GetDebit(txin, filter);
         if (!MoneyRange(nDebit)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": value out of range");
         }
     }
 
     return nDebit;
 }
 
 bool CWallet::IsAllFromMe(const CTransaction &tx,
                           const isminefilter &filter) const {
     LOCK(cs_wallet);
 
     for (const CTxIn &txin : tx.vin) {
         auto mi = mapWallet.find(txin.prevout.GetTxId());
         if (mi == mapWallet.end()) {
             // Any unknown inputs can't be from us.
             return false;
         }
 
         const CWalletTx &prev = (*mi).second;
 
         if (txin.prevout.GetN() >= prev.tx->vout.size()) {
             // Invalid input!
             return false;
         }
 
         if (!(IsMine(prev.tx->vout[txin.prevout.GetN()]) & filter)) {
             return false;
         }
     }
 
     return true;
 }
 
 Amount CWallet::GetCredit(const CTransaction &tx,
                           const isminefilter &filter) const {
     Amount nCredit = Amount::zero();
     for (const CTxOut &txout : tx.vout) {
         nCredit += GetCredit(txout, filter);
         if (!MoneyRange(nCredit)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": value out of range");
         }
     }
 
     return nCredit;
 }
 
 Amount CWallet::GetChange(const CTransaction &tx) const {
     Amount nChange = Amount::zero();
     for (const CTxOut &txout : tx.vout) {
         nChange += GetChange(txout);
         if (!MoneyRange(nChange)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": value out of range");
         }
     }
 
     return nChange;
 }
 
 CPubKey CWallet::GenerateNewSeed() {
     assert(!IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
     CKey key;
     key.MakeNewKey(true);
     return DeriveNewSeed(key);
 }
 
 CPubKey CWallet::DeriveNewSeed(const CKey &key) {
     int64_t nCreationTime = GetTime();
     CKeyMetadata metadata(nCreationTime);
 
     // Calculate the seed
     CPubKey seed = key.GetPubKey();
     assert(key.VerifyPubKey(seed));
 
     // Set the hd keypath to "s" -> Seed, refers the seed to itself
     metadata.hdKeypath = "s";
     metadata.hd_seed_id = seed.GetID();
 
     LOCK(cs_wallet);
 
     // mem store the metadata
     mapKeyMetadata[seed.GetID()] = metadata;
 
     // Write the key&metadata to the database
     if (!AddKeyPubKey(key, seed)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": AddKeyPubKey failed");
     }
 
     return seed;
 }
 
 void CWallet::SetHDSeed(const CPubKey &seed) {
     LOCK(cs_wallet);
 
     // Store the keyid (hash160) together with the child index counter in the
     // database as a hdchain object.
     CHDChain newHdChain;
     newHdChain.nVersion = CanSupportFeature(FEATURE_HD_SPLIT)
                               ? CHDChain::VERSION_HD_CHAIN_SPLIT
                               : CHDChain::VERSION_HD_BASE;
     newHdChain.seed_id = seed.GetID();
     SetHDChain(newHdChain, false);
     NotifyCanGetAddressesChanged();
     UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
 }
 
 void CWallet::SetHDChain(const CHDChain &chain, bool memonly) {
     LOCK(cs_wallet);
     if (!memonly && !WalletBatch(*database).WriteHDChain(chain)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing chain failed");
     }
 
     hdChain = chain;
 }
 
 bool CWallet::IsHDEnabled() const {
     return !hdChain.seed_id.IsNull();
 }
 
 bool CWallet::CanGenerateKeys() {
     // A wallet can generate keys if it has an HD seed (IsHDEnabled) or it is a
     // non-HD wallet (pre FEATURE_HD)
     LOCK(cs_wallet);
     return IsHDEnabled() || !CanSupportFeature(FEATURE_HD);
 }
 
 bool CWallet::CanGetAddresses(bool internal) {
     LOCK(cs_wallet);
     // Check if the keypool has keys
     bool keypool_has_keys;
     if (internal && CanSupportFeature(FEATURE_HD_SPLIT)) {
         keypool_has_keys = setInternalKeyPool.size() > 0;
     } else {
         keypool_has_keys = KeypoolCountExternalKeys() > 0;
     }
     // If the keypool doesn't have keys, check if we can generate them
     if (!keypool_has_keys) {
         return CanGenerateKeys();
     }
     return keypool_has_keys;
 }
 
 void CWallet::SetWalletFlag(uint64_t flags) {
     LOCK(cs_wallet);
     m_wallet_flags |= flags;
     if (!WalletBatch(*database).WriteWalletFlags(m_wallet_flags)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing wallet flags failed");
     }
 }
 
 void CWallet::UnsetWalletFlag(uint64_t flag) {
     LOCK(cs_wallet);
     m_wallet_flags &= ~flag;
     if (!WalletBatch(*database).WriteWalletFlags(m_wallet_flags)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing wallet flags failed");
     }
 }
 
 bool CWallet::IsWalletFlagSet(uint64_t flag) {
     return (m_wallet_flags & flag);
 }
 
 bool CWallet::SetWalletFlags(uint64_t overwriteFlags, bool memonly) {
     LOCK(cs_wallet);
     m_wallet_flags = overwriteFlags;
     if (((overwriteFlags & g_known_wallet_flags) >> 32) ^
         (overwriteFlags >> 32)) {
         // contains unknown non-tolerable wallet flags
         return false;
     }
     if (!memonly && !WalletBatch(*database).WriteWalletFlags(m_wallet_flags)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing wallet flags failed");
     }
 
     return true;
 }
 
 int64_t CWalletTx::GetTxTime() const {
     int64_t n = nTimeSmart;
     return n ? n : nTimeReceived;
 }
 
 // Helper for producing a max-sized low-S low-R signature (eg 71 bytes)
 // or a max-sized low-S signature (e.g. 72 bytes) if use_max_sig is true
 bool CWallet::DummySignInput(CTxIn &tx_in, const CTxOut &txout,
                              bool use_max_sig) const {
     // Fill in dummy signatures for fee calculation.
     const CScript &scriptPubKey = txout.scriptPubKey;
     SignatureData sigdata;
 
     if (!ProduceSignature(*this,
                           use_max_sig ? DUMMY_MAXIMUM_SIGNATURE_CREATOR
                                       : DUMMY_SIGNATURE_CREATOR,
                           scriptPubKey, sigdata)) {
         return false;
     }
 
     UpdateInput(tx_in, sigdata);
     return true;
 }
 
 // Helper for producing a bunch of max-sized low-S low-R signatures (eg 71
 // bytes)
 bool CWallet::DummySignTx(CMutableTransaction &txNew,
                           const std::vector<CTxOut> &txouts,
                           bool use_max_sig) const {
     // Fill in dummy signatures for fee calculation.
     int nIn = 0;
     for (const auto &txout : txouts) {
         if (!DummySignInput(txNew.vin[nIn], txout, use_max_sig)) {
             return false;
         }
 
         nIn++;
     }
     return true;
 }
 
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet, bool use_max_sig) {
     std::vector<CTxOut> txouts;
     // Look up the inputs.  We should have already checked that this transaction
     // IsAllFromMe(ISMINE_SPENDABLE), so every input should already be in our
     // wallet, with a valid index into the vout array, and the ability to sign.
     for (auto &input : tx.vin) {
         const auto mi = wallet->mapWallet.find(input.prevout.GetTxId());
         if (mi == wallet->mapWallet.end()) {
             return -1;
         }
         assert(input.prevout.GetN() < mi->second.tx->vout.size());
         txouts.emplace_back(mi->second.tx->vout[input.prevout.GetN()]);
     }
     return CalculateMaximumSignedTxSize(tx, wallet, txouts, use_max_sig);
 }
 
 // txouts needs to be in the order of tx.vin
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet,
                                      const std::vector<CTxOut> &txouts,
                                      bool use_max_sig) {
     CMutableTransaction txNew(tx);
     if (!wallet->DummySignTx(txNew, txouts, use_max_sig)) {
         // This should never happen, because IsAllFromMe(ISMINE_SPENDABLE)
         // implies that we can sign for every input.
         return -1;
     }
     return GetSerializeSize(txNew, PROTOCOL_VERSION);
 }
 
 int CalculateMaximumSignedInputSize(const CTxOut &txout, const CWallet *wallet,
                                     bool use_max_sig) {
     CMutableTransaction txn;
     txn.vin.push_back(CTxIn(COutPoint()));
     if (!wallet->DummySignInput(txn.vin[0], txout, use_max_sig)) {
         // This should never happen, because IsAllFromMe(ISMINE_SPENDABLE)
         // implies that we can sign for every input.
         return -1;
     }
     return GetSerializeSize(txn.vin[0], PROTOCOL_VERSION);
 }
 
 void CWalletTx::GetAmounts(std::list<COutputEntry> &listReceived,
                            std::list<COutputEntry> &listSent, Amount &nFee,
                            const isminefilter &filter) const {
     nFee = Amount::zero();
     listReceived.clear();
     listSent.clear();
 
     // Compute fee:
     Amount nDebit = GetDebit(filter);
     // debit>0 means we signed/sent this transaction.
     if (nDebit > Amount::zero()) {
         Amount nValueOut = tx->GetValueOut();
         nFee = (nDebit - nValueOut);
     }
 
     // Sent/received.
     for (unsigned int i = 0; i < tx->vout.size(); ++i) {
         const CTxOut &txout = tx->vout[i];
         isminetype fIsMine = pwallet->IsMine(txout);
         // Only need to handle txouts if AT LEAST one of these is true:
         //   1) they debit from us (sent)
         //   2) the output is to us (received)
         if (nDebit > Amount::zero()) {
             // Don't report 'change' txouts
             if (pwallet->IsChange(txout)) {
                 continue;
             }
         } else if (!(fIsMine & filter)) {
             continue;
         }
 
         // In either case, we need to get the destination address.
         CTxDestination address;
 
         if (!ExtractDestination(txout.scriptPubKey, address) &&
             !txout.scriptPubKey.IsUnspendable()) {
             pwallet->WalletLogPrintf("CWalletTx::GetAmounts: Unknown "
                                      "transaction type found, txid %s\n",
                                      this->GetId().ToString());
             address = CNoDestination();
         }
 
         COutputEntry output = {address, txout.nValue, (int)i};
 
         // If we are debited by the transaction, add the output as a "sent"
         // entry.
         if (nDebit > Amount::zero()) {
             listSent.push_back(output);
         }
 
         // If we are receiving the output, add it as a "received" entry.
         if (fIsMine & filter) {
             listReceived.push_back(output);
         }
     }
 }
 
 /**
  * Scan active chain for relevant transactions after importing keys. This should
  * be called whenever new keys are added to the wallet, with the oldest key
  * creation time.
  *
  * @return Earliest timestamp that could be successfully scanned from. Timestamp
  * returned will be higher than startTime if relevant blocks could not be read.
  */
 int64_t CWallet::RescanFromTime(int64_t startTime,
                                 const WalletRescanReserver &reserver,
                                 bool update) {
     // Find starting block. May be null if nCreateTime is greater than the
     // highest blockchain timestamp, in which case there is nothing that needs
     // to be scanned.
-    CBlockIndex *startBlock = nullptr;
+    BlockHash start_block;
     {
         auto locked_chain = chain().lock();
-        startBlock =
-            ::ChainActive().FindEarliestAtLeast(startTime - TIMESTAMP_WINDOW);
-        WalletLogPrintf("%s: Rescanning last %i blocks\n", __func__,
-                        startBlock
-                            ? ::ChainActive().Height() - startBlock->nHeight + 1
-                            : 0);
+        const Optional<int> start_height = locked_chain->findFirstBlockWithTime(
+            startTime - TIMESTAMP_WINDOW, &start_block);
+        const Optional<int> tip_height = locked_chain->getHeight();
+        WalletLogPrintf(
+            "%s: Rescanning last %i blocks\n", __func__,
+            tip_height && start_height ? *tip_height - *start_height + 1 : 0);
     }
 
-    if (startBlock) {
-        const CBlockIndex *failedBlock, *stop_block;
+    if (!start_block.IsNull()) {
         // TODO: this should take into account failure by ScanResult::USER_ABORT
-        if (ScanResult::FAILURE ==
-            ScanForWalletTransactions(startBlock, nullptr, reserver,
-                                      failedBlock, stop_block, update)) {
-            return failedBlock->GetBlockTimeMax() + TIMESTAMP_WINDOW + 1;
+        ScanResult result = ScanForWalletTransactions(start_block, BlockHash(),
+                                                      reserver, update);
+        if (result.status == ScanResult::FAILURE) {
+            int64_t time_max;
+            if (!chain().findBlock(result.failed_block, nullptr /* block */,
+                                   nullptr /* time */, &time_max)) {
+                throw std::logic_error(
+                    "ScanForWalletTransactions returned invalid block hash");
+            }
+            return time_max + TIMESTAMP_WINDOW + 1;
         }
     }
     return startTime;
 }
 
 /**
- * Scan the block chain (starting in pindexStart) for transactions from or to
+ * Scan the block chain (starting in start_block) for transactions from or to
  * us. If fUpdate is true, found transactions that already exist in the wallet
  * will be updated.
  *
- * @param[in] pindexStop if not a nullptr, the scan will stop at this
- * block-index
- * @param[out] failed_block if FAILURE is returned, the most recent block
- *     that could not be scanned, otherwise nullptr
- * @param[out] stop_block the most recent block that could be scanned,
- *     otherwise nullptr if no block could be scanned
+ * @param[in] start_block if not null, the scan will start at this block instead
+ *            of the genesis block
+ * @param[in] stop_block if not null, the scan will stop at this block instead
+ *            of the chain tip
  *
  * @return ScanResult indicating success or failure of the scan. SUCCESS if
  * scan was successful. FAILURE if a complete rescan was not possible (due to
  * pruning or corruption). USER_ABORT if the rescan was aborted before it
  * could complete.
  *
- * @pre Caller needs to make sure pindexStop (and the optional pindexStart) are
+ * @pre Caller needs to make sure start_block (and the optional stop_block) are
  * on the main chain after to the addition of any new keys you want to detect
  * transactions for.
  */
 CWallet::ScanResult CWallet::ScanForWalletTransactions(
-    const CBlockIndex *const pindexStart, const CBlockIndex *const pindexStop,
-    const WalletRescanReserver &reserver, const CBlockIndex *&failed_block,
-    const CBlockIndex *&stop_block, bool fUpdate) {
+    const BlockHash &start_block, const BlockHash &stop_block,
+    const WalletRescanReserver &reserver, bool fUpdate) {
     int64_t nNow = GetTime();
 
     assert(reserver.isReserved());
-    if (pindexStop) {
-        assert(pindexStop->nHeight >= pindexStart->nHeight);
-    }
 
-    const CBlockIndex *pindex = pindexStart;
-    failed_block = nullptr;
-    stop_block = nullptr;
+    BlockHash block_hash = start_block;
+    ScanResult result;
 
-    if (pindex) {
-        WalletLogPrintf("Rescan started from block %d...\n", pindex->nHeight);
-    }
+    WalletLogPrintf("Rescan started from block %s...\n",
+                    start_block.ToString());
 
     {
         fAbortRescan = false;
 
         // Show rescan progress in GUI as dialog or on splashscreen, if -rescan
         // on startup.
         ShowProgress(strprintf("%s " + _("Rescanning..."), GetDisplayName()),
                      0);
-        CBlockIndex *tip = nullptr;
+        BlockHash tip_hash;
+        Optional<int> block_height;
         double progress_begin;
         double progress_end;
         {
             auto locked_chain = chain().lock();
-            progress_begin =
-                GuessVerificationProgress(chainParams.TxData(), pindex);
-            if (pindexStop == nullptr) {
-                tip = ::ChainActive().Tip();
-                progress_end =
-                    GuessVerificationProgress(chainParams.TxData(), tip);
-            } else {
-                progress_end =
-                    GuessVerificationProgress(chainParams.TxData(), pindexStop);
+            if (Optional<int> tip_height = locked_chain->getHeight()) {
+                tip_hash = locked_chain->getBlockHash(*tip_height);
             }
+            block_height = locked_chain->getBlockHeight(block_hash);
+            progress_begin = chain().guessVerificationProgress(block_hash);
+            progress_end = chain().guessVerificationProgress(
+                stop_block.IsNull() ? tip_hash : stop_block);
         }
         double progress_current = progress_begin;
-        while (pindex && !fAbortRescan && !ShutdownRequested()) {
-            if (pindex->nHeight % 100 == 0 &&
+        while (block_height && !fAbortRescan && !ShutdownRequested()) {
+            if (*block_height % 100 == 0 &&
                 progress_end - progress_begin > 0.0) {
                 ShowProgress(
                     strprintf("%s " + _("Rescanning..."), GetDisplayName()),
                     std::max(
                         1,
                         std::min(99, (int)((progress_current - progress_begin) /
                                            (progress_end - progress_begin) *
                                            100))));
             }
             if (GetTime() >= nNow + 60) {
                 nNow = GetTime();
                 WalletLogPrintf("Still rescanning. At block %d. Progress=%f\n",
-                                pindex->nHeight, progress_current);
+                                *block_height, progress_current);
             }
 
             CBlock block;
-            if (ReadBlockFromDisk(block, pindex, chainParams.GetConsensus())) {
+            if (chain().findBlock(block_hash, &block) && !block.IsNull()) {
                 auto locked_chain = chain().lock();
                 LOCK(cs_wallet);
-                if (pindex && !::ChainActive().Contains(pindex)) {
+                if (!locked_chain->getBlockHeight(block_hash)) {
                     // Abort scan if current block is no longer active, to
                     // prevent marking transactions as coming from the wrong
                     // block.
-                    failed_block = pindex;
+                    // TODO: This should return success instead of failure, see
+                    // https://github.com/bitcoin/bitcoin/pull/14711#issuecomment-458342518
+                    result.failed_block = block_hash;
+                    result.status = ScanResult::FAILURE;
                     break;
                 }
                 for (size_t posInBlock = 0; posInBlock < block.vtx.size();
                      ++posInBlock) {
-                    SyncTransaction(block.vtx[posInBlock], pindex, posInBlock,
-                                    fUpdate);
+                    SyncTransaction(block.vtx[posInBlock], block_hash,
+                                    posInBlock, fUpdate);
                 }
                 // scan succeeded, record block as most recent successfully
                 // scanned
-                stop_block = pindex;
+                result.stop_block = block_hash;
+                result.stop_height = *block_height;
             } else {
                 // could not scan block, keep scanning but record this block as
                 // the most recent failure
-                failed_block = pindex;
+                result.failed_block = block_hash;
+                result.status = ScanResult::FAILURE;
             }
-            if (pindex == pindexStop) {
+            if (block_hash == stop_block) {
                 break;
             }
             {
                 auto locked_chain = chain().lock();
-                pindex = ::ChainActive().Next(pindex);
+                Optional<int> tip_height = locked_chain->getHeight();
+                if (!tip_height || *tip_height <= block_height ||
+                    !locked_chain->getBlockHeight(block_hash)) {
+                    // break successfully when rescan has reached the tip, or
+                    // previous block is no longer on the chain due to a reorg
+                    break;
+                }
+
+                // increment block and verification progress
+                block_hash = locked_chain->getBlockHash(++*block_height);
                 progress_current =
-                    GuessVerificationProgress(chainParams.TxData(), pindex);
-                if (pindexStop == nullptr && tip != ::ChainActive().Tip()) {
-                    tip = ::ChainActive().Tip();
+                    chain().guessVerificationProgress(block_hash);
+
+                // handle updated tip hash
+                const BlockHash prev_tip_hash = tip_hash;
+                tip_hash = locked_chain->getBlockHash(*tip_height);
+                if (stop_block.IsNull() && prev_tip_hash != tip_hash) {
                     // in case the tip has changed, update progress max
-                    progress_end =
-                        GuessVerificationProgress(chainParams.TxData(), tip);
+                    progress_end = chain().guessVerificationProgress(tip_hash);
                 }
             }
         }
 
         // Hide progress dialog in GUI.
         ShowProgress(strprintf("%s " + _("Rescanning..."), GetDisplayName()),
                      100);
-        if (pindex && fAbortRescan) {
+        if (block_height && fAbortRescan) {
             WalletLogPrintf("Rescan aborted at block %d. Progress=%f\n",
-                            pindex->nHeight, progress_current);
-            return ScanResult::USER_ABORT;
-        } else if (pindex && ShutdownRequested()) {
+                            block_height.value_or(0), progress_current);
+            result.status = ScanResult::USER_ABORT;
+        } else if (block_height && ShutdownRequested()) {
             WalletLogPrintf("Rescan interrupted by shutdown request at block "
                             "%d. Progress=%f\n",
-                            pindex->nHeight, progress_current);
-            return ScanResult::USER_ABORT;
+                            block_height.value_or(0), progress_current);
+            result.status = ScanResult::USER_ABORT;
         }
     }
 
-    return failed_block ? ScanResult::FAILURE : ScanResult::SUCCESS;
+    return result;
 }
 
 void CWallet::ReacceptWalletTransactions() {
     // If transactions aren't being broadcasted, don't let them into local
     // mempool either.
     if (!fBroadcastTransactions) {
         return;
     }
 
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
     std::map<int64_t, CWalletTx *> mapSorted;
 
     // Sort pending wallet transactions based on their initial wallet insertion
     // order.
     for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
         const TxId &wtxid = item.first;
         CWalletTx &wtx = item.second;
         assert(wtx.GetId() == wtxid);
 
         int nDepth = wtx.GetDepthInMainChain(*locked_chain);
 
         if (!wtx.IsCoinBase() && (nDepth == 0 && !wtx.isAbandoned())) {
             mapSorted.insert(std::make_pair(wtx.nOrderPos, &wtx));
         }
     }
 
     // Try to add wallet transactions to memory pool.
     for (const std::pair<const int64_t, CWalletTx *> &item : mapSorted) {
         CWalletTx &wtx = *(item.second);
         CValidationState state;
         wtx.AcceptToMemoryPool(*locked_chain, maxTxFee, state);
     }
 }
 
 bool CWalletTx::RelayWalletTransaction(interfaces::Chain::Lock &locked_chain,
                                        CConnman *connman) {
     assert(pwallet->GetBroadcastTransactions());
     if (IsCoinBase() || isAbandoned() ||
         GetDepthInMainChain(locked_chain) != 0) {
         return false;
     }
 
     CValidationState state;
     // GetDepthInMainChain already catches known conflicts.
     if (InMempool() || AcceptToMemoryPool(locked_chain, maxTxFee, state)) {
         pwallet->WalletLogPrintf("Relaying wtx %s\n", GetId().ToString());
         if (connman) {
             CInv inv(MSG_TX, GetId());
             connman->ForEachNode(
                 [&inv](CNode *pnode) { pnode->PushInventory(inv); });
             return true;
         }
     }
 
     return false;
 }
 
 std::set<TxId> CWalletTx::GetConflicts() const {
     std::set<TxId> result;
     if (pwallet != nullptr) {
         const TxId &txid = GetId();
         result = pwallet->GetConflicts(txid);
         result.erase(txid);
     }
 
     return result;
 }
 
 Amount CWalletTx::GetDebit(const isminefilter &filter) const {
     if (tx->vin.empty()) {
         return Amount::zero();
     }
 
     Amount debit = Amount::zero();
     if (filter & ISMINE_SPENDABLE) {
         if (fDebitCached) {
             debit += nDebitCached;
         } else {
             nDebitCached = pwallet->GetDebit(*tx, ISMINE_SPENDABLE);
             fDebitCached = true;
             debit += nDebitCached;
         }
     }
 
     if (filter & ISMINE_WATCH_ONLY) {
         if (fWatchDebitCached) {
             debit += nWatchDebitCached;
         } else {
             nWatchDebitCached = pwallet->GetDebit(*tx, ISMINE_WATCH_ONLY);
             fWatchDebitCached = true;
             debit += Amount(nWatchDebitCached);
         }
     }
 
     return debit;
 }
 
 Amount CWalletTx::GetCredit(interfaces::Chain::Lock &locked_chain,
                             const isminefilter &filter) const {
     // Must wait until coinbase is safely deep enough in the chain before
     // valuing it.
     if (IsImmatureCoinBase(locked_chain)) {
         return Amount::zero();
     }
 
     Amount credit = Amount::zero();
     if (filter & ISMINE_SPENDABLE) {
         // GetBalance can assume transactions in mapWallet won't change.
         if (fCreditCached) {
             credit += nCreditCached;
         } else {
             nCreditCached = pwallet->GetCredit(*tx, ISMINE_SPENDABLE);
             fCreditCached = true;
             credit += nCreditCached;
         }
     }
 
     if (filter & ISMINE_WATCH_ONLY) {
         if (fWatchCreditCached) {
             credit += nWatchCreditCached;
         } else {
             nWatchCreditCached = pwallet->GetCredit(*tx, ISMINE_WATCH_ONLY);
             fWatchCreditCached = true;
             credit += nWatchCreditCached;
         }
     }
 
     return credit;
 }
 
 Amount CWalletTx::GetImmatureCredit(interfaces::Chain::Lock &locked_chain,
                                     bool fUseCache) const {
     if (IsImmatureCoinBase(locked_chain) && IsInMainChain(locked_chain)) {
         if (fUseCache && fImmatureCreditCached) {
             return nImmatureCreditCached;
         }
 
         nImmatureCreditCached = pwallet->GetCredit(*tx, ISMINE_SPENDABLE);
         fImmatureCreditCached = true;
         return nImmatureCreditCached;
     }
 
     return Amount::zero();
 }
 
 Amount CWalletTx::GetAvailableCredit(interfaces::Chain::Lock &locked_chain,
                                      bool fUseCache,
                                      const isminefilter &filter) const {
     if (pwallet == nullptr) {
         return Amount::zero();
     }
 
     // Must wait until coinbase is safely deep enough in the chain before
     // valuing it.
     if (IsImmatureCoinBase(locked_chain)) {
         return Amount::zero();
     }
 
     Amount *cache = nullptr;
     bool *cache_used = nullptr;
 
     if (filter == ISMINE_SPENDABLE) {
         cache = &nAvailableCreditCached;
         cache_used = &fAvailableCreditCached;
     } else if (filter == ISMINE_WATCH_ONLY) {
         cache = &nAvailableWatchCreditCached;
         cache_used = &fAvailableWatchCreditCached;
     }
 
     if (fUseCache && cache_used && *cache_used) {
         return *cache;
     }
 
     Amount nCredit = Amount::zero();
     const TxId &txid = GetId();
     for (uint32_t i = 0; i < tx->vout.size(); i++) {
         if (!pwallet->IsSpent(locked_chain, COutPoint(txid, i))) {
             const CTxOut &txout = tx->vout[i];
             nCredit += pwallet->GetCredit(txout, filter);
             if (!MoneyRange(nCredit)) {
                 throw std::runtime_error(std::string(__func__) +
                                          " : value out of range");
             }
         }
     }
 
     if (cache) {
         *cache = nCredit;
         *cache_used = true;
     }
     return nCredit;
 }
 
 Amount
 CWalletTx::GetImmatureWatchOnlyCredit(interfaces::Chain::Lock &locked_chain,
                                       const bool fUseCache) const {
     if (IsImmatureCoinBase(locked_chain) && IsInMainChain(locked_chain)) {
         if (fUseCache && fImmatureWatchCreditCached) {
             return nImmatureWatchCreditCached;
         }
 
         nImmatureWatchCreditCached = pwallet->GetCredit(*tx, ISMINE_WATCH_ONLY);
         fImmatureWatchCreditCached = true;
         return nImmatureWatchCreditCached;
     }
 
     return Amount::zero();
 }
 
 Amount CWalletTx::GetChange() const {
     if (fChangeCached) {
         return nChangeCached;
     }
 
     nChangeCached = pwallet->GetChange(*tx);
     fChangeCached = true;
     return nChangeCached;
 }
 
 bool CWalletTx::InMempool() const {
     return fInMempool;
 }
 
 bool CWalletTx::IsTrusted(interfaces::Chain::Lock &locked_chain) const {
     // Temporary, for CheckFinalTx below. Removed in upcoming commit.
     LockAnnotation lock(::cs_main);
 
     // Quick answer in most cases
     if (!CheckFinalTx(*tx)) {
         return false;
     }
 
     int nDepth = GetDepthInMainChain(locked_chain);
     if (nDepth >= 1) {
         return true;
     }
 
     if (nDepth < 0) {
         return false;
     }
 
     // using wtx's cached debit
     if (!pwallet->m_spend_zero_conf_change || !IsFromMe(ISMINE_ALL)) {
         return false;
     }
 
     // Don't trust unconfirmed transactions from us unless they are in the
     // mempool.
     if (!InMempool()) {
         return false;
     }
 
     // Trusted if all inputs are from us and are in the mempool:
     for (const CTxIn &txin : tx->vin) {
         // Transactions not sent by us: not trusted
         const CWalletTx *parent = pwallet->GetWalletTx(txin.prevout.GetTxId());
         if (parent == nullptr) {
             return false;
         }
 
         const CTxOut &parentOut = parent->tx->vout[txin.prevout.GetN()];
         if (pwallet->IsMine(parentOut) != ISMINE_SPENDABLE) {
             return false;
         }
     }
 
     return true;
 }
 
 bool CWalletTx::IsEquivalentTo(const CWalletTx &_tx) const {
     CMutableTransaction tx1{*this->tx};
     CMutableTransaction tx2{*_tx.tx};
     for (auto &txin : tx1.vin) {
         txin.scriptSig = CScript();
     }
 
     for (auto &txin : tx2.vin) {
         txin.scriptSig = CScript();
     }
 
     return CTransaction(tx1) == CTransaction(tx2);
 }
 
 std::vector<uint256>
 CWallet::ResendWalletTransactionsBefore(interfaces::Chain::Lock &locked_chain,
                                         int64_t nTime, CConnman *connman) {
     std::vector<uint256> result;
 
     LOCK(cs_wallet);
 
     // Sort them in chronological order
     std::multimap<unsigned int, CWalletTx *> mapSorted;
     for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
         CWalletTx &wtx = item.second;
         // Don't rebroadcast if newer than nTime:
         if (wtx.nTimeReceived > nTime) {
             continue;
         }
 
         mapSorted.insert(std::make_pair(wtx.nTimeReceived, &wtx));
     }
 
     for (const std::pair<const unsigned int, CWalletTx *> &item : mapSorted) {
         CWalletTx &wtx = *item.second;
         if (wtx.RelayWalletTransaction(locked_chain, connman)) {
             result.push_back(wtx.GetId());
         }
     }
 
     return result;
 }
 
 void CWallet::ResendWalletTransactions(int64_t nBestBlockTime,
                                        CConnman *connman) {
     // Do this infrequently and randomly to avoid giving away that these are our
     // transactions.
     if (GetTime() < nNextResend || !fBroadcastTransactions) {
         return;
     }
 
     bool fFirst = (nNextResend == 0);
     nNextResend = GetTime() + GetRand(30 * 60);
     if (fFirst) {
         return;
     }
 
     // Only do it if there's been a new block since last time
     if (nBestBlockTime < nLastResend) {
         return;
     }
 
     nLastResend = GetTime();
 
     // Temporary. Removed in upcoming lock cleanup
     auto locked_chain = chain().assumeLocked();
     // Rebroadcast unconfirmed txes older than 5 minutes before the last block
     // was found:
     std::vector<uint256> relayed = ResendWalletTransactionsBefore(
         *locked_chain, nBestBlockTime - 5 * 60, connman);
     if (!relayed.empty()) {
         WalletLogPrintf("%s: rebroadcast %u unconfirmed transactions\n",
                         __func__, relayed.size());
     }
 }
 
 /** @} */ // end of mapWallet
 
 /**
  * @defgroup Actions
  *
  * @{
  */
 Amount CWallet::GetBalance(const isminefilter &filter,
                            const int min_depth) const {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.second;
         if (pcoin->IsTrusted(*locked_chain) &&
             pcoin->GetDepthInMainChain(*locked_chain) >= min_depth) {
             nTotal += pcoin->GetAvailableCredit(*locked_chain, true, filter);
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetUnconfirmedBalance() const {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.second;
         if (!pcoin->IsTrusted(*locked_chain) &&
             pcoin->GetDepthInMainChain(*locked_chain) == 0 &&
             pcoin->InMempool()) {
             nTotal += pcoin->GetAvailableCredit(*locked_chain);
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetImmatureBalance() const {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.second;
         nTotal += pcoin->GetImmatureCredit(*locked_chain);
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetUnconfirmedWatchOnlyBalance() const {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.second;
         if (!pcoin->IsTrusted(*locked_chain) &&
             pcoin->GetDepthInMainChain(*locked_chain) == 0 &&
             pcoin->InMempool()) {
             nTotal += pcoin->GetAvailableCredit(*locked_chain, true,
                                                 ISMINE_WATCH_ONLY);
         }
     }
 
     return nTotal;
 }
 
 Amount CWallet::GetImmatureWatchOnlyBalance() const {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     Amount nTotal = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx *pcoin = &entry.second;
         nTotal += pcoin->GetImmatureWatchOnlyCredit(*locked_chain);
     }
 
     return nTotal;
 }
 
 // Calculate total balance in a different way from GetBalance. The biggest
 // difference is that GetBalance sums up all unspent TxOuts paying to the
 // wallet, while this sums up both spent and unspent TxOuts paying to the
 // wallet, and then subtracts the values of TxIns spending from the wallet. This
 // also has fewer restrictions on which unconfirmed transactions are considered
 // trusted.
 Amount CWallet::GetLegacyBalance(const isminefilter &filter,
                                  int minDepth) const {
     // Temporary, for CheckFinalTx below. Removed in upcoming commit.
     LockAnnotation lock(::cs_main);
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     Amount balance = Amount::zero();
     for (const auto &entry : mapWallet) {
         const CWalletTx &wtx = entry.second;
         const int depth = wtx.GetDepthInMainChain(*locked_chain);
         if (depth < 0 || !CheckFinalTx(*wtx.tx) ||
             wtx.IsImmatureCoinBase(*locked_chain)) {
             continue;
         }
 
         // Loop through tx outputs and add incoming payments. For outgoing txs,
         // treat change outputs specially, as part of the amount debited.
         Amount debit = wtx.GetDebit(filter);
         const bool outgoing = debit > Amount::zero();
         for (const CTxOut &out : wtx.tx->vout) {
             if (outgoing && IsChange(out)) {
                 debit -= out.nValue;
             } else if (IsMine(out) & filter && depth >= minDepth) {
                 balance += out.nValue;
             }
         }
 
         // For outgoing txs, subtract amount debited.
         if (outgoing) {
             balance -= debit;
         }
     }
 
     return balance;
 }
 
 Amount CWallet::GetAvailableBalance(const CCoinControl *coinControl) const {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     Amount balance = Amount::zero();
     std::vector<COutput> vCoins;
     AvailableCoins(*locked_chain, vCoins, true, coinControl);
     for (const COutput &out : vCoins) {
         if (out.fSpendable) {
             balance += out.tx->tx->vout[out.i].nValue;
         }
     }
     return balance;
 }
 
 void CWallet::AvailableCoins(interfaces::Chain::Lock &locked_chain,
                              std::vector<COutput> &vCoins, bool fOnlySafe,
                              const CCoinControl *coinControl,
                              const Amount nMinimumAmount,
                              const Amount nMaximumAmount,
                              const Amount nMinimumSumAmount,
                              const uint64_t nMaximumCount, const int nMinDepth,
                              const int nMaxDepth) const {
     AssertLockHeld(cs_main);
     AssertLockHeld(cs_wallet);
 
     vCoins.clear();
     Amount nTotal = Amount::zero();
 
     for (const auto &entry : mapWallet) {
         const TxId &wtxid = entry.first;
         const CWalletTx *pcoin = &entry.second;
 
         if (!CheckFinalTx(*pcoin->tx)) {
             continue;
         }
 
         if (pcoin->IsImmatureCoinBase(locked_chain)) {
             continue;
         }
 
         int nDepth = pcoin->GetDepthInMainChain(locked_chain);
         if (nDepth < 0) {
             continue;
         }
 
         // We should not consider coins which aren't at least in our mempool.
         // It's possible for these to be conflicted via ancestors which we may
         // never be able to detect.
         if (nDepth == 0 && !pcoin->InMempool()) {
             continue;
         }
 
         bool safeTx = pcoin->IsTrusted(locked_chain);
 
         // Bitcoin-ABC: Removed check that prevents consideration of coins from
         // transactions that are replacing other transactions. This check based
         // on pcoin->mapValue.count("replaces_txid") which was not being set
         // anywhere.
 
         // Similarly, we should not consider coins from transactions that have
         // been replaced. In the example above, we would want to prevent
         // creation of a transaction A' spending an output of A, because if
         // transaction B were initially confirmed, conflicting with A and A', we
         // wouldn't want to the user to create a transaction D intending to
         // replace A', but potentially resulting in a scenario where A, A', and
         // D could all be accepted (instead of just B and D, or just A and A'
         // like the user would want).
 
         // Bitcoin-ABC: retained this check as 'replaced_by_txid' is still set
         // in the wallet code.
         if (nDepth == 0 && pcoin->mapValue.count("replaced_by_txid")) {
             safeTx = false;
         }
 
         if (fOnlySafe && !safeTx) {
             continue;
         }
 
         if (nDepth < nMinDepth || nDepth > nMaxDepth) {
             continue;
         }
 
         for (uint32_t i = 0; i < pcoin->tx->vout.size(); i++) {
             if (pcoin->tx->vout[i].nValue < nMinimumAmount ||
                 pcoin->tx->vout[i].nValue > nMaximumAmount) {
                 continue;
             }
 
             const COutPoint outpoint(wtxid, i);
 
             if (coinControl && coinControl->HasSelected() &&
                 !coinControl->fAllowOtherInputs &&
                 !coinControl->IsSelected(outpoint)) {
                 continue;
             }
 
             if (IsLockedCoin(outpoint)) {
                 continue;
             }
 
             if (IsSpent(locked_chain, outpoint)) {
                 continue;
             }
 
             isminetype mine = IsMine(pcoin->tx->vout[i]);
 
             if (mine == ISMINE_NO) {
                 continue;
             }
 
             bool solvable = IsSolvable(*this, pcoin->tx->vout[i].scriptPubKey);
             bool spendable =
                 ((mine & ISMINE_SPENDABLE) != ISMINE_NO) ||
                 (((mine & ISMINE_WATCH_ONLY) != ISMINE_NO) &&
                  (coinControl && coinControl->fAllowWatchOnly && solvable));
 
             vCoins.push_back(
                 COutput(pcoin, i, nDepth, spendable, solvable, safeTx,
                         (coinControl && coinControl->fAllowWatchOnly)));
 
             // Checks the sum amount of all UTXO's.
             if (nMinimumSumAmount != MAX_MONEY) {
                 nTotal += pcoin->tx->vout[i].nValue;
 
                 if (nTotal >= nMinimumSumAmount) {
                     return;
                 }
             }
 
             // Checks the maximum number of UTXO's.
             if (nMaximumCount > 0 && vCoins.size() >= nMaximumCount) {
                 return;
             }
         }
     }
 }
 
 std::map<CTxDestination, std::vector<COutput>>
 CWallet::ListCoins(interfaces::Chain::Lock &locked_chain) const {
     AssertLockHeld(cs_main);
     AssertLockHeld(cs_wallet);
 
     std::map<CTxDestination, std::vector<COutput>> result;
     std::vector<COutput> availableCoins;
 
     AvailableCoins(locked_chain, availableCoins);
 
     for (const auto &coin : availableCoins) {
         CTxDestination address;
         if (coin.fSpendable &&
             ExtractDestination(
                 FindNonChangeParentOutput(*coin.tx->tx, coin.i).scriptPubKey,
                 address)) {
             result[address].emplace_back(std::move(coin));
         }
     }
 
     std::vector<COutPoint> lockedCoins;
     ListLockedCoins(lockedCoins);
     for (const auto &output : lockedCoins) {
         auto it = mapWallet.find(output.GetTxId());
         if (it != mapWallet.end()) {
             int depth = it->second.GetDepthInMainChain(locked_chain);
             if (depth >= 0 && output.GetN() < it->second.tx->vout.size() &&
                 IsMine(it->second.tx->vout[output.GetN()]) ==
                     ISMINE_SPENDABLE) {
                 CTxDestination address;
                 if (ExtractDestination(
                         FindNonChangeParentOutput(*it->second.tx, output.GetN())
                             .scriptPubKey,
                         address)) {
                     result[address].emplace_back(
                         &it->second, output.GetN(), depth, true /* spendable */,
                         true /* solvable */, false /* safe */);
                 }
             }
         }
     }
 
     return result;
 }
 
 const CTxOut &CWallet::FindNonChangeParentOutput(const CTransaction &tx,
                                                  int output) const {
     const CTransaction *ptx = &tx;
     int n = output;
     while (IsChange(ptx->vout[n]) && ptx->vin.size() > 0) {
         const COutPoint &prevout = ptx->vin[0].prevout;
         auto it = mapWallet.find(prevout.GetTxId());
         if (it == mapWallet.end() ||
             it->second.tx->vout.size() <= prevout.GetN() ||
             !IsMine(it->second.tx->vout[prevout.GetN()])) {
             break;
         }
         ptx = it->second.tx.get();
         n = prevout.GetN();
     }
     return ptx->vout[n];
 }
 
 bool CWallet::SelectCoinsMinConf(
     const Amount nTargetValue, const CoinEligibilityFilter &eligibility_filter,
     std::vector<OutputGroup> groups, std::set<CInputCoin> &setCoinsRet,
     Amount &nValueRet, const CoinSelectionParams &coin_selection_params,
     bool &bnb_used) const {
     setCoinsRet.clear();
     nValueRet = Amount::zero();
 
     std::vector<OutputGroup> utxo_pool;
     if (coin_selection_params.use_bnb) {
         // Get long term estimate
         CCoinControl temp;
         temp.m_confirm_target = 1008;
         CFeeRate long_term_feerate = GetMinimumFeeRate(*this, temp, g_mempool);
 
         // Calculate cost of change
         Amount cost_of_change =
             dustRelayFee.GetFee(coin_selection_params.change_spend_size) +
             coin_selection_params.effective_fee.GetFee(
                 coin_selection_params.change_output_size);
 
         // Filter by the min conf specs and add to utxo_pool and calculate
         // effective value
         for (OutputGroup &group : groups) {
             if (!group.EligibleForSpending(eligibility_filter)) {
                 continue;
             }
 
             group.fee = Amount::zero();
             group.long_term_fee = Amount::zero();
             group.effective_value = Amount::zero();
             for (auto it = group.m_outputs.begin();
                  it != group.m_outputs.end();) {
                 const CInputCoin &coin = *it;
                 Amount effective_value =
                     coin.txout.nValue -
                     (coin.m_input_bytes < 0
                          ? Amount::zero()
                          : coin_selection_params.effective_fee.GetFee(
                                coin.m_input_bytes));
                 // Only include outputs that are positive effective value (i.e.
                 // not dust)
                 if (effective_value > Amount::zero()) {
                     group.fee +=
                         coin.m_input_bytes < 0
                             ? Amount::zero()
                             : coin_selection_params.effective_fee.GetFee(
                                   coin.m_input_bytes);
                     group.long_term_fee +=
                         coin.m_input_bytes < 0
                             ? Amount::zero()
                             : long_term_feerate.GetFee(coin.m_input_bytes);
                     group.effective_value += effective_value;
                     ++it;
                 } else {
                     it = group.Discard(coin);
                 }
             }
             if (group.effective_value > Amount::zero()) {
                 utxo_pool.push_back(group);
             }
         }
         // Calculate the fees for things that aren't inputs
         Amount not_input_fees = coin_selection_params.effective_fee.GetFee(
             coin_selection_params.tx_noinputs_size);
         bnb_used = true;
         return SelectCoinsBnB(utxo_pool, nTargetValue, cost_of_change,
                               setCoinsRet, nValueRet, not_input_fees);
     } else {
         // Filter by the min conf specs and add to utxo_pool
         for (const OutputGroup &group : groups) {
             if (!group.EligibleForSpending(eligibility_filter)) {
                 continue;
             }
             utxo_pool.push_back(group);
         }
         bnb_used = false;
         return KnapsackSolver(nTargetValue, utxo_pool, setCoinsRet, nValueRet);
     }
 }
 
 bool CWallet::SelectCoins(const std::vector<COutput> &vAvailableCoins,
                           const Amount nTargetValue,
                           std::set<CInputCoin> &setCoinsRet, Amount &nValueRet,
                           const CCoinControl &coin_control,
                           CoinSelectionParams &coin_selection_params,
                           bool &bnb_used) const {
     std::vector<COutput> vCoins(vAvailableCoins);
 
     // coin control -> return all selected outputs (we want all selected to go
     // into the transaction for sure)
     if (coin_control.HasSelected() && !coin_control.fAllowOtherInputs) {
         // We didn't use BnB here, so set it to false.
         bnb_used = false;
 
         for (const COutput &out : vCoins) {
             if (!out.fSpendable) {
                 continue;
             }
 
             nValueRet += out.tx->tx->vout[out.i].nValue;
             setCoinsRet.insert(out.GetInputCoin());
         }
 
         return (nValueRet >= nTargetValue);
     }
 
     // Calculate value from preset inputs and store them.
     std::set<CInputCoin> setPresetCoins;
     Amount nValueFromPresetInputs = Amount::zero();
 
     std::vector<COutPoint> vPresetInputs;
     coin_control.ListSelected(vPresetInputs);
 
     for (const COutPoint &outpoint : vPresetInputs) {
         // For now, don't use BnB if preset inputs are selected. TODO: Enable
         // this later
         bnb_used = false;
         coin_selection_params.use_bnb = false;
 
         std::map<TxId, CWalletTx>::const_iterator it =
             mapWallet.find(outpoint.GetTxId());
         if (it == mapWallet.end()) {
             // TODO: Allow non-wallet inputs
             return false;
         }
 
         const CWalletTx *pcoin = &it->second;
         // Clearly invalid input, fail.
         if (pcoin->tx->vout.size() <= outpoint.GetN()) {
             return false;
         }
 
         // Just to calculate the marginal byte size
         nValueFromPresetInputs += pcoin->tx->vout[outpoint.GetN()].nValue;
         setPresetCoins.insert(CInputCoin(pcoin->tx, outpoint.GetN()));
     }
 
     // Remove preset inputs from vCoins
     for (std::vector<COutput>::iterator it = vCoins.begin();
          it != vCoins.end() && coin_control.HasSelected();) {
         if (setPresetCoins.count(it->GetInputCoin())) {
             it = vCoins.erase(it);
         } else {
             ++it;
         }
     }
 
     // form groups from remaining coins; note that preset coins will not
     // automatically have their associated (same address) coins included
     if (coin_control.m_avoid_partial_spends &&
         vCoins.size() > OUTPUT_GROUP_MAX_ENTRIES) {
         // Cases where we have 11+ outputs all pointing to the same destination
         // may result in privacy leaks as they will potentially be
         // deterministically sorted. We solve that by explicitly shuffling the
         // outputs before processing
         Shuffle(vCoins.begin(), vCoins.end(), FastRandomContext());
     }
     std::vector<OutputGroup> groups =
         GroupOutputs(vCoins, !coin_control.m_avoid_partial_spends);
 
     size_t max_ancestors = std::max<size_t>(
         1, gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT));
     size_t max_descendants = std::max<size_t>(
         1, gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT));
     bool fRejectLongChains = gArgs.GetBoolArg(
         "-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
 
     bool res =
         nTargetValue <= nValueFromPresetInputs ||
         SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                            CoinEligibilityFilter(1, 6, 0), groups, setCoinsRet,
                            nValueRet, coin_selection_params, bnb_used) ||
         SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                            CoinEligibilityFilter(1, 1, 0), groups, setCoinsRet,
                            nValueRet, coin_selection_params, bnb_used) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                             CoinEligibilityFilter(0, 1, 2), groups, setCoinsRet,
                             nValueRet, coin_selection_params, bnb_used)) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(
              nTargetValue - nValueFromPresetInputs,
              CoinEligibilityFilter(0, 1, std::min<size_t>(4, max_ancestors / 3),
                                    std::min<size_t>(4, max_descendants / 3)),
              groups, setCoinsRet, nValueRet, coin_selection_params,
              bnb_used)) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                             CoinEligibilityFilter(0, 1, max_ancestors / 2,
                                                   max_descendants / 2),
                             groups, setCoinsRet, nValueRet,
                             coin_selection_params, bnb_used)) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                             CoinEligibilityFilter(0, 1, max_ancestors - 1,
                                                   max_descendants - 1),
                             groups, setCoinsRet, nValueRet,
                             coin_selection_params, bnb_used)) ||
         (m_spend_zero_conf_change && !fRejectLongChains &&
          SelectCoinsMinConf(
              nTargetValue - nValueFromPresetInputs,
              CoinEligibilityFilter(0, 1, std::numeric_limits<uint64_t>::max()),
              groups, setCoinsRet, nValueRet, coin_selection_params, bnb_used));
 
     // Because SelectCoinsMinConf clears the setCoinsRet, we now add the
     // possible inputs to the coinset.
     util::insert(setCoinsRet, setPresetCoins);
 
     // Add preset inputs to the total value selected.
     nValueRet += nValueFromPresetInputs;
 
     return res;
 }
 
 bool CWallet::SignTransaction(CMutableTransaction &tx) {
     // sign the new tx
     int nIn = 0;
     for (CTxIn &input : tx.vin) {
         auto mi = mapWallet.find(input.prevout.GetTxId());
         if (mi == mapWallet.end() ||
             input.prevout.GetN() >= mi->second.tx->vout.size()) {
             return false;
         }
         const CScript &scriptPubKey =
             mi->second.tx->vout[input.prevout.GetN()].scriptPubKey;
         const Amount amount = mi->second.tx->vout[input.prevout.GetN()].nValue;
         SignatureData sigdata;
         SigHashType sigHashType = SigHashType().withForkId();
         if (!ProduceSignature(*this,
                               MutableTransactionSignatureCreator(
                                   &tx, nIn, amount, sigHashType),
                               scriptPubKey, sigdata)) {
             return false;
         }
         UpdateInput(input, sigdata);
         nIn++;
     }
     return true;
 }
 
 bool CWallet::FundTransaction(CMutableTransaction &tx, Amount &nFeeRet,
                               int &nChangePosInOut, std::string &strFailReason,
                               bool lockUnspents,
                               const std::set<int> &setSubtractFeeFromOutputs,
                               CCoinControl coinControl) {
     std::vector<CRecipient> vecSend;
 
     // Turn the txout set into a CRecipient vector.
     for (size_t idx = 0; idx < tx.vout.size(); idx++) {
         const CTxOut &txOut = tx.vout[idx];
         CRecipient recipient = {txOut.scriptPubKey, txOut.nValue,
                                 setSubtractFeeFromOutputs.count(idx) == 1};
         vecSend.push_back(recipient);
     }
 
     coinControl.fAllowOtherInputs = true;
 
     for (const CTxIn &txin : tx.vin) {
         coinControl.Select(txin.prevout);
     }
 
     // Acquire the locks to prevent races to the new locked unspents between the
     // CreateTransaction call and LockCoin calls (when lockUnspents is true).
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     CReserveKey reservekey(this);
     CTransactionRef tx_new;
     if (!CreateTransaction(*locked_chain, vecSend, tx_new, reservekey, nFeeRet,
                            nChangePosInOut, strFailReason, coinControl,
                            false)) {
         return false;
     }
 
     if (nChangePosInOut != -1) {
         tx.vout.insert(tx.vout.begin() + nChangePosInOut,
                        tx_new->vout[nChangePosInOut]);
         // We don't have the normal Create/Commit cycle, and don't want to
         // risk reusing change, so just remove the key from the keypool
         // here.
         reservekey.KeepKey();
     }
 
     // Copy output sizes from new transaction; they may have had the fee
     // subtracted from them.
     for (size_t idx = 0; idx < tx.vout.size(); idx++) {
         tx.vout[idx].nValue = tx_new->vout[idx].nValue;
     }
 
     // Add new txins (keeping original txin scriptSig/order)
     for (const CTxIn &txin : tx_new->vin) {
         if (!coinControl.IsSelected(txin.prevout)) {
             tx.vin.push_back(txin);
 
             if (lockUnspents) {
                 LockCoin(txin.prevout);
             }
         }
     }
 
     return true;
 }
 
 static bool IsCurrentForAntiFeeSniping(interfaces::Chain::Lock &locked_chain) {
     if (IsInitialBlockDownload()) {
         return false;
     }
 
     // in seconds
     constexpr int64_t MAX_ANTI_FEE_SNIPING_TIP_AGE = 8 * 60 * 60;
     if (ChainActive().Tip()->GetBlockTime() <
         (GetTime() - MAX_ANTI_FEE_SNIPING_TIP_AGE)) {
         return false;
     }
     return true;
 }
 
 /**
  * Return a height-based locktime for new transactions (uses the height of the
  * current chain tip unless we are not synced with the current chain
  */
 static uint32_t
 GetLocktimeForNewTransaction(interfaces::Chain::Lock &locked_chain) {
+    uint32_t const height = locked_chain.getHeight().value_or(-1);
     uint32_t locktime;
     // Discourage fee sniping.
     //
     // For a large miner the value of the transactions in the best block and
     // the mempool can exceed the cost of deliberately attempting to mine two
     // blocks to orphan the current best block. By setting nLockTime such that
     // only the next block can include the transaction, we discourage this
     // practice as the height restricted and limited blocksize gives miners
     // considering fee sniping fewer options for pulling off this attack.
     //
     // A simple way to think about this is from the wallet's point of view we
     // always want the blockchain to move forward. By setting nLockTime this
     // way we're basically making the statement that we only want this
     // transaction to appear in the next block; we don't want to potentially
     // encourage reorgs by allowing transactions to appear at lower heights
     // than the next block in forks of the best chain.
     //
     // Of course, the subsidy is high enough, and transaction volume low
     // enough, that fee sniping isn't a problem yet, but by implementing a fix
     // now we ensure code won't be written that makes assumptions about
     // nLockTime that preclude a fix later.
     if (IsCurrentForAntiFeeSniping(locked_chain)) {
-        locktime = ChainActive().Height();
+        locktime = height;
 
         // Secondly occasionally randomly pick a nLockTime even further back, so
         // that transactions that are delayed after signing for whatever reason,
         // e.g. high-latency mix networks and some CoinJoin implementations,
         // have better privacy.
         if (GetRandInt(10) == 0) {
             locktime = std::max(0, int(locktime) - GetRandInt(100));
         }
     } else {
         // If our chain is lagging behind, we can't discourage fee sniping nor
         // help the privacy of high-latency transactions. To avoid leaking a
         // potentially unique "nLockTime fingerprint", set nLockTime to a
         // constant.
         locktime = 0;
     }
-    assert(locktime <= uint32_t(ChainActive().Height()));
+    assert(locktime <= height);
     assert(locktime < LOCKTIME_THRESHOLD);
     return locktime;
 }
 
 OutputType
 CWallet::TransactionChangeType(OutputType change_type,
                                const std::vector<CRecipient> &vecSend) {
     // If -changetype is specified, always use that change type.
     if (change_type != OutputType::CHANGE_AUTO) {
         return change_type;
     }
 
     // if m_default_address_type is legacy, use legacy address as change.
     if (m_default_address_type == OutputType::LEGACY) {
         return OutputType::LEGACY;
     }
 
     // else use m_default_address_type for change
     return m_default_address_type;
 }
 
 bool CWallet::CreateTransaction(interfaces::Chain::Lock &locked_chainIn,
                                 const std::vector<CRecipient> &vecSend,
                                 CTransactionRef &tx, CReserveKey &reservekey,
                                 Amount &nFeeRet, int &nChangePosInOut,
                                 std::string &strFailReason,
                                 const CCoinControl &coinControl, bool sign) {
     Amount nValue = Amount::zero();
     int nChangePosRequest = nChangePosInOut;
     unsigned int nSubtractFeeFromAmount = 0;
     for (const auto &recipient : vecSend) {
         if (nValue < Amount::zero() || recipient.nAmount < Amount::zero()) {
             strFailReason = _("Transaction amounts must not be negative");
             return false;
         }
 
         nValue += recipient.nAmount;
 
         if (recipient.fSubtractFeeFromAmount) {
             nSubtractFeeFromAmount++;
         }
     }
 
     if (vecSend.empty()) {
         strFailReason = _("Transaction must have at least one recipient");
         return false;
     }
 
     CMutableTransaction txNew;
 
     txNew.nLockTime = GetLocktimeForNewTransaction(locked_chainIn);
 
     {
         std::set<CInputCoin> setCoins;
         auto locked_chain = chain().lock();
         LOCK(cs_wallet);
 
         std::vector<COutput> vAvailableCoins;
         AvailableCoins(*locked_chain, vAvailableCoins, true, &coinControl);
         // Parameters for coin selection, init with dummy
         CoinSelectionParams coin_selection_params;
 
         // Create change script that will be used if we need change
         // TODO: pass in scriptChange instead of reservekey so
         // change transaction isn't always pay-to-bitcoin-address
         CScript scriptChange;
 
         // coin control: send change to custom address
         if (!boost::get<CNoDestination>(&coinControl.destChange)) {
             scriptChange = GetScriptForDestination(coinControl.destChange);
 
             // no coin control: send change to newly generated address
         } else {
             // Note: We use a new key here to keep it from being obvious
             // which side is the change.
             //  The drawback is that by not reusing a previous key, the
             //  change may be lost if a backup is restored, if the backup
             //  doesn't have the new private key for the change. If we
             //  reused the old key, it would be possible to add code to look
             //  for and rediscover unknown transactions that were written
             //  with keys of ours to recover post-backup change.
 
             // Reserve a new key pair from key pool
             if (IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
                 strFailReason =
                     _("Can't generate a change-address key. Private keys "
                       "are disabled for this wallet.");
                 return false;
             }
             CPubKey vchPubKey;
             bool ret;
             ret = reservekey.GetReservedKey(vchPubKey, true);
             if (!ret) {
                 strFailReason =
                     _("Keypool ran out, please call keypoolrefill first");
                 return false;
             }
 
             const OutputType change_type = TransactionChangeType(
                 coinControl.m_change_type ? *coinControl.m_change_type
                                           : m_default_change_type,
                 vecSend);
 
             LearnRelatedScripts(vchPubKey, change_type);
             scriptChange = GetScriptForDestination(
                 GetDestinationForKey(vchPubKey, change_type));
         }
         CTxOut change_prototype_txout(Amount::zero(), scriptChange);
         coin_selection_params.change_output_size =
             GetSerializeSize(change_prototype_txout);
 
         // Get the fee rate to use effective values in coin selection
         CFeeRate nFeeRateNeeded =
             GetMinimumFeeRate(*this, coinControl, g_mempool);
 
         nFeeRet = Amount::zero();
         bool pick_new_inputs = true;
         Amount nValueIn = Amount::zero();
 
         // BnB selector is the only selector used when this is true.
         // That should only happen on the first pass through the loop.
         // If we are doing subtract fee from recipient, then don't use BnB
         coin_selection_params.use_bnb = nSubtractFeeFromAmount == 0;
         // Start with no fee and loop until there is enough fee
         while (true) {
             nChangePosInOut = nChangePosRequest;
             txNew.vin.clear();
             txNew.vout.clear();
             bool fFirst = true;
 
             Amount nValueToSelect = nValue;
             if (nSubtractFeeFromAmount == 0) {
                 nValueToSelect += nFeeRet;
             }
 
             // Static size overhead + outputs vsize. 4 nVersion, 4 nLocktime, 1
             // input count, 1 output count
             coin_selection_params.tx_noinputs_size = 10;
             // vouts to the payees
             for (const auto &recipient : vecSend) {
                 CTxOut txout(recipient.nAmount, recipient.scriptPubKey);
 
                 if (recipient.fSubtractFeeFromAmount) {
                     assert(nSubtractFeeFromAmount != 0);
                     // Subtract fee equally from each selected recipient.
                     txout.nValue -= nFeeRet / int(nSubtractFeeFromAmount);
 
                     // First receiver pays the remainder not divisible by output
                     // count.
                     if (fFirst) {
                         fFirst = false;
                         txout.nValue -= nFeeRet % int(nSubtractFeeFromAmount);
                     }
                 }
 
                 // Include the fee cost for outputs. Note this is only used for
                 // BnB right now
                 coin_selection_params.tx_noinputs_size +=
                     ::GetSerializeSize(txout, PROTOCOL_VERSION);
 
                 if (IsDust(txout, dustRelayFee)) {
                     if (recipient.fSubtractFeeFromAmount &&
                         nFeeRet > Amount::zero()) {
                         if (txout.nValue < Amount::zero()) {
                             strFailReason = _("The transaction amount is "
                                               "too small to pay the fee");
                         } else {
                             strFailReason =
                                 _("The transaction amount is too small to "
                                   "send after the fee has been deducted");
                         }
                     } else {
                         strFailReason = _("Transaction amount too small");
                     }
 
                     return false;
                 }
 
                 txNew.vout.push_back(txout);
             }
 
             // Choose coins to use
             bool bnb_used;
             if (pick_new_inputs) {
                 nValueIn = Amount::zero();
                 setCoins.clear();
                 coin_selection_params.change_spend_size =
                     CalculateMaximumSignedInputSize(change_prototype_txout,
                                                     this);
                 coin_selection_params.effective_fee = nFeeRateNeeded;
                 if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins,
                                  nValueIn, coinControl, coin_selection_params,
                                  bnb_used)) {
                     // If BnB was used, it was the first pass. No longer the
                     // first pass and continue loop with knapsack.
                     if (bnb_used) {
                         coin_selection_params.use_bnb = false;
                         continue;
                     } else {
                         strFailReason = _("Insufficient funds");
                         return false;
                     }
                 }
             }
 
             const Amount nChange = nValueIn - nValueToSelect;
             if (nChange > Amount::zero()) {
                 // Fill a vout to ourself.
                 CTxOut newTxOut(nChange, scriptChange);
 
                 // Never create dust outputs; if we would, just add the dust to
                 // the fee.
                 // The nChange when BnB is used is always going to go to fees.
                 if (IsDust(newTxOut, dustRelayFee) || bnb_used) {
                     nChangePosInOut = -1;
                     nFeeRet += nChange;
                 } else {
                     if (nChangePosInOut == -1) {
                         // Insert change txn at random position:
                         nChangePosInOut = GetRandInt(txNew.vout.size() + 1);
                     } else if ((unsigned int)nChangePosInOut >
                                txNew.vout.size()) {
                         strFailReason = _("Change index out of range");
                         return false;
                     }
 
                     std::vector<CTxOut>::iterator position =
                         txNew.vout.begin() + nChangePosInOut;
                     txNew.vout.insert(position, newTxOut);
                 }
             } else {
                 nChangePosInOut = -1;
             }
 
             // Dummy fill vin for maximum size estimation
             //
             for (const auto &coin : setCoins) {
                 txNew.vin.push_back(CTxIn(coin.outpoint, CScript()));
             }
 
             CTransaction txNewConst(txNew);
             int nBytes = CalculateMaximumSignedTxSize(
                 txNewConst, this, coinControl.fAllowWatchOnly);
             if (nBytes < 0) {
                 strFailReason = _("Signing transaction failed");
                 return false;
             }
 
             Amount nFeeNeeded =
                 GetMinimumFee(*this, nBytes, coinControl, g_mempool);
 
             // If we made it here and we aren't even able to meet the relay fee
             // on the next pass, give up because we must be at the maximum
             // allowed fee.
             if (nFeeNeeded < ::minRelayTxFee.GetFee(nBytes)) {
                 strFailReason = _("Transaction too large for fee policy");
                 return false;
             }
 
             if (nFeeRet >= nFeeNeeded) {
                 // Reduce fee to only the needed amount if possible. This
                 // prevents potential overpayment in fees if the coins selected
                 // to meet nFeeNeeded result in a transaction that requires less
                 // fee than the prior iteration.
 
                 // If we have no change and a big enough excess fee, then try to
                 // construct transaction again only without picking new inputs.
                 // We now know we only need the smaller fee (because of reduced
                 // tx size) and so we should add a change output. Only try this
                 // once.
                 if (nChangePosInOut == -1 && nSubtractFeeFromAmount == 0 &&
                     pick_new_inputs) {
                     // Add 2 as a buffer in case increasing # of outputs changes
                     // compact size
                     unsigned int tx_size_with_change =
                         nBytes + coin_selection_params.change_output_size + 2;
                     Amount fee_needed_with_change = GetMinimumFee(
                         *this, tx_size_with_change, coinControl, g_mempool);
                     Amount minimum_value_for_change =
                         GetDustThreshold(change_prototype_txout, dustRelayFee);
                     if (nFeeRet >=
                         fee_needed_with_change + minimum_value_for_change) {
                         pick_new_inputs = false;
                         nFeeRet = fee_needed_with_change;
                         continue;
                     }
                 }
 
                 // If we have change output already, just increase it
                 if (nFeeRet > nFeeNeeded && nChangePosInOut != -1 &&
                     nSubtractFeeFromAmount == 0) {
                     Amount extraFeePaid = nFeeRet - nFeeNeeded;
                     std::vector<CTxOut>::iterator change_position =
                         txNew.vout.begin() + nChangePosInOut;
                     change_position->nValue += extraFeePaid;
                     nFeeRet -= extraFeePaid;
                 }
 
                 // Done, enough fee included.
                 break;
             } else if (!pick_new_inputs) {
                 // This shouldn't happen, we should have had enough excess fee
                 // to pay for the new output and still meet nFeeNeeded.
                 // Or we should have just subtracted fee from recipients and
                 // nFeeNeeded should not have changed.
                 strFailReason =
                     _("Transaction fee and change calculation failed");
                 return false;
             }
 
             // Try to reduce change to include necessary fee.
             if (nChangePosInOut != -1 && nSubtractFeeFromAmount == 0) {
                 Amount additionalFeeNeeded = nFeeNeeded - nFeeRet;
                 std::vector<CTxOut>::iterator change_position =
                     txNew.vout.begin() + nChangePosInOut;
                 // Only reduce change if remaining amount is still a large
                 // enough output.
                 if (change_position->nValue >=
                     MIN_FINAL_CHANGE + additionalFeeNeeded) {
                     change_position->nValue -= additionalFeeNeeded;
                     nFeeRet += additionalFeeNeeded;
                     // Done, able to increase fee from change.
                     break;
                 }
             }
 
             // If subtracting fee from recipients, we now know what fee we
             // need to subtract, we have no reason to reselect inputs.
             if (nSubtractFeeFromAmount > 0) {
                 pick_new_inputs = false;
             }
 
             // Include more fee and try again.
             nFeeRet = nFeeNeeded;
             coin_selection_params.use_bnb = false;
             continue;
         }
 
         if (nChangePosInOut == -1) {
             // Return any reserved key if we don't have change
             reservekey.ReturnKey();
         }
 
         // Shuffle selected coins and fill in final vin
         txNew.vin.clear();
         std::vector<CInputCoin> selected_coins(setCoins.begin(),
                                                setCoins.end());
         Shuffle(selected_coins.begin(), selected_coins.end(),
                 FastRandomContext());
 
         // Note how the sequence number is set to non-maxint so that
         // the nLockTime set above actually works.
         for (const auto &coin : selected_coins) {
             txNew.vin.push_back(
                 CTxIn(coin.outpoint, CScript(),
                       std::numeric_limits<uint32_t>::max() - 1));
         }
 
         if (sign) {
             SigHashType sigHashType = SigHashType().withForkId();
 
             int nIn = 0;
             for (const auto &coin : selected_coins) {
                 const CScript &scriptPubKey = coin.txout.scriptPubKey;
                 SignatureData sigdata;
 
                 if (!ProduceSignature(
                         *this,
                         MutableTransactionSignatureCreator(
                             &txNew, nIn, coin.txout.nValue, sigHashType),
                         scriptPubKey, sigdata)) {
                     strFailReason = _("Signing transaction failed");
                     return false;
                 }
 
                 UpdateInput(txNew.vin.at(nIn), sigdata);
                 nIn++;
             }
         }
 
         // Return the constructed transaction data.
         tx = MakeTransactionRef(std::move(txNew));
 
         // Limit size.
         if (tx->GetTotalSize() >= MAX_STANDARD_TX_SIZE) {
             strFailReason = _("Transaction too large");
             return false;
         }
     }
 
     if (gArgs.GetBoolArg("-walletrejectlongchains",
                          DEFAULT_WALLET_REJECT_LONG_CHAINS)) {
         // Lastly, ensure this tx will pass the mempool's chain limits.
         LockPoints lp;
         CTxMemPoolEntry entry(tx, Amount::zero(), 0, 0, false, 0, lp);
         CTxMemPool::setEntries setAncestors;
         size_t nLimitAncestors =
             gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT);
         size_t nLimitAncestorSize =
             gArgs.GetArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT) *
             1000;
         size_t nLimitDescendants =
             gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT);
         size_t nLimitDescendantSize =
             gArgs.GetArg("-limitdescendantsize",
                          DEFAULT_DESCENDANT_SIZE_LIMIT) *
             1000;
         std::string errString;
         LOCK(::g_mempool.cs);
         if (!g_mempool.CalculateMemPoolAncestors(
                 entry, setAncestors, nLimitAncestors, nLimitAncestorSize,
                 nLimitDescendants, nLimitDescendantSize, errString)) {
             strFailReason = _("Transaction has too long of a mempool chain");
             return false;
         }
     }
 
     return true;
 }
 
 /**
  * Call after CreateTransaction unless you want to abort
  */
 bool CWallet::CommitTransaction(
     CTransactionRef tx, mapValue_t mapValue,
     std::vector<std::pair<std::string, std::string>> orderForm,
     CReserveKey &reservekey, CConnman *connman, CValidationState &state) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     CWalletTx wtxNew(this, std::move(tx));
     wtxNew.mapValue = std::move(mapValue);
     wtxNew.vOrderForm = std::move(orderForm);
     wtxNew.fTimeReceivedIsTxTime = true;
     wtxNew.fFromMe = true;
 
     WalletLogPrintfToBeContinued("CommitTransaction:\n%s",
                                  wtxNew.tx->ToString());
 
     // Take key pair from key pool so it won't be used again.
     reservekey.KeepKey();
 
     // Add tx to wallet, because if it has change it's also ours, otherwise just
     // for transaction history.
     AddToWallet(wtxNew);
 
     // Notify that old coins are spent.
     for (const CTxIn &txin : wtxNew.tx->vin) {
         CWalletTx &coin = mapWallet.at(txin.prevout.GetTxId());
         coin.BindWallet(this);
         NotifyTransactionChanged(this, coin.GetId(), CT_UPDATED);
     }
 
     // Get the inserted-CWalletTx from mapWallet so that the
     // fInMempool flag is cached properly
     CWalletTx &wtx = mapWallet.at(wtxNew.GetId());
 
     if (fBroadcastTransactions) {
         // Broadcast
         if (!wtx.AcceptToMemoryPool(*locked_chain, maxTxFee, state)) {
             WalletLogPrintf("CommitTransaction(): Transaction cannot be "
                             "broadcast immediately, %s\n",
                             FormatStateMessage(state));
             // TODO: if we expect the failure to be long term or permanent,
             // instead delete wtx from the wallet and return failure.
         } else {
             wtx.RelayWalletTransaction(*locked_chain, connman);
         }
     }
 
     return true;
 }
 
 DBErrors CWallet::LoadWallet(bool &fFirstRunRet) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     fFirstRunRet = false;
     DBErrors nLoadWalletRet = WalletBatch(*database, "cr+").LoadWallet(this);
     if (nLoadWalletRet == DBErrors::NEED_REWRITE) {
         if (database->Rewrite("\x04pool")) {
             setInternalKeyPool.clear();
             setExternalKeyPool.clear();
             m_pool_key_to_index.clear();
             // Note: can't top-up keypool here, because wallet is locked.
             // User will be prompted to unlock wallet the next operation
             // that requires a new key.
         }
     }
 
     {
         LOCK(cs_KeyStore);
         // This wallet is in its first run if all of these are empty
         fFirstRunRet = mapKeys.empty() && mapCryptedKeys.empty() &&
                        mapWatchKeys.empty() && setWatchOnly.empty() &&
                        mapScripts.empty() &&
                        !IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS) &&
                        !IsWalletFlagSet(WALLET_FLAG_BLANK_WALLET);
     }
 
     if (nLoadWalletRet != DBErrors::LOAD_OK) {
         return nLoadWalletRet;
     }
 
     return DBErrors::LOAD_OK;
 }
 
 DBErrors CWallet::ZapSelectTx(std::vector<TxId> &txIdsIn,
                               std::vector<TxId> &txIdsOut) {
     // mapWallet
     AssertLockHeld(cs_wallet);
     DBErrors nZapSelectTxRet =
         WalletBatch(*database, "cr+").ZapSelectTx(txIdsIn, txIdsOut);
     for (const TxId &txid : txIdsOut) {
         const auto &it = mapWallet.find(txid);
         wtxOrdered.erase(it->second.m_it_wtxOrdered);
         mapWallet.erase(it);
     }
 
     if (nZapSelectTxRet == DBErrors::NEED_REWRITE) {
         if (database->Rewrite("\x04pool")) {
             setInternalKeyPool.clear();
             setExternalKeyPool.clear();
             m_pool_key_to_index.clear();
             // Note: can't top-up keypool here, because wallet is locked.
             // User will be prompted to unlock wallet the next operation
             // that requires a new key.
         }
     }
 
     if (nZapSelectTxRet != DBErrors::LOAD_OK) {
         return nZapSelectTxRet;
     }
 
     MarkDirty();
 
     return DBErrors::LOAD_OK;
 }
 
 DBErrors CWallet::ZapWalletTx(std::vector<CWalletTx> &vWtx) {
     DBErrors nZapWalletTxRet = WalletBatch(*database, "cr+").ZapWalletTx(vWtx);
     if (nZapWalletTxRet == DBErrors::NEED_REWRITE) {
         if (database->Rewrite("\x04pool")) {
             LOCK(cs_wallet);
             setInternalKeyPool.clear();
             setExternalKeyPool.clear();
             m_pool_key_to_index.clear();
             // Note: can't top-up keypool here, because wallet is locked.
             // User will be prompted to unlock wallet the next operation
             // that requires a new key.
         }
     }
 
     if (nZapWalletTxRet != DBErrors::LOAD_OK) {
         return nZapWalletTxRet;
     }
 
     return DBErrors::LOAD_OK;
 }
 
 bool CWallet::SetAddressBook(const CTxDestination &address,
                              const std::string &strName,
                              const std::string &strPurpose) {
     bool fUpdated = false;
     {
         // mapAddressBook
         LOCK(cs_wallet);
         std::map<CTxDestination, CAddressBookData>::iterator mi =
             mapAddressBook.find(address);
         fUpdated = mi != mapAddressBook.end();
         mapAddressBook[address].name = strName;
         // Update purpose only if requested.
         if (!strPurpose.empty()) {
             mapAddressBook[address].purpose = strPurpose;
         }
     }
 
     NotifyAddressBookChanged(this, address, strName,
                              ::IsMine(*this, address) != ISMINE_NO, strPurpose,
                              (fUpdated ? CT_UPDATED : CT_NEW));
     if (!strPurpose.empty() &&
         !WalletBatch(*database).WritePurpose(address, strPurpose)) {
         return false;
     }
     return WalletBatch(*database).WriteName(address, strName);
 }
 
 bool CWallet::DelAddressBook(const CTxDestination &address) {
     {
         // mapAddressBook
         LOCK(cs_wallet);
 
         // Delete destdata tuples associated with address.
         for (const std::pair<const std::string, std::string> &item :
              mapAddressBook[address].destdata) {
             WalletBatch(*database).EraseDestData(address, item.first);
         }
 
         mapAddressBook.erase(address);
     }
 
     NotifyAddressBookChanged(this, address, "",
                              ::IsMine(*this, address) != ISMINE_NO, "",
                              CT_DELETED);
 
     WalletBatch(*database).ErasePurpose(address);
     return WalletBatch(*database).EraseName(address);
 }
 
 const std::string &CWallet::GetLabelName(const CScript &scriptPubKey) const {
     CTxDestination address;
     if (ExtractDestination(scriptPubKey, address) &&
         !scriptPubKey.IsUnspendable()) {
         auto mi = mapAddressBook.find(address);
         if (mi != mapAddressBook.end()) {
             return mi->second.name;
         }
     }
     // A scriptPubKey that doesn't have an entry in the address book is
     // associated with the default label ("").
     const static std::string DEFAULT_LABEL_NAME;
     return DEFAULT_LABEL_NAME;
 }
 
 /**
  * Mark old keypool keys as used, and generate all new keys.
  */
 bool CWallet::NewKeyPool() {
     if (IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         return false;
     }
     LOCK(cs_wallet);
     WalletBatch batch(*database);
 
     for (const int64_t nIndex : setInternalKeyPool) {
         batch.ErasePool(nIndex);
     }
     setInternalKeyPool.clear();
 
     for (const int64_t nIndex : setExternalKeyPool) {
         batch.ErasePool(nIndex);
     }
     setExternalKeyPool.clear();
 
     for (int64_t nIndex : set_pre_split_keypool) {
         batch.ErasePool(nIndex);
     }
     set_pre_split_keypool.clear();
 
     m_pool_key_to_index.clear();
 
     if (!TopUpKeyPool()) {
         return false;
     }
 
     WalletLogPrintf("CWallet::NewKeyPool rewrote keypool\n");
     return true;
 }
 
 size_t CWallet::KeypoolCountExternalKeys() {
     // setExternalKeyPool
     AssertLockHeld(cs_wallet);
     return setExternalKeyPool.size() + set_pre_split_keypool.size();
 }
 
 void CWallet::LoadKeyPool(int64_t nIndex, const CKeyPool &keypool) {
     AssertLockHeld(cs_wallet);
     if (keypool.m_pre_split) {
         set_pre_split_keypool.insert(nIndex);
     } else if (keypool.fInternal) {
         setInternalKeyPool.insert(nIndex);
     } else {
         setExternalKeyPool.insert(nIndex);
     }
     m_max_keypool_index = std::max(m_max_keypool_index, nIndex);
     m_pool_key_to_index[keypool.vchPubKey.GetID()] = nIndex;
 
     // If no metadata exists yet, create a default with the pool key's
     // creation time. Note that this may be overwritten by actually
     // stored metadata for that key later, which is fine.
     CKeyID keyid = keypool.vchPubKey.GetID();
     if (mapKeyMetadata.count(keyid) == 0) {
         mapKeyMetadata[keyid] = CKeyMetadata(keypool.nTime);
     }
 }
 
 bool CWallet::TopUpKeyPool(unsigned int kpSize) {
     if (!CanGenerateKeys()) {
         return false;
     }
     {
         LOCK(cs_wallet);
 
         if (IsLocked()) {
             return false;
         }
 
         // Top up key pool
         unsigned int nTargetSize;
         if (kpSize > 0) {
             nTargetSize = kpSize;
         } else {
             nTargetSize = std::max<int64_t>(
                 gArgs.GetArg("-keypool", DEFAULT_KEYPOOL_SIZE), 0);
         }
 
         // count amount of available keys (internal, external)
         // make sure the keypool of external and internal keys fits the user
         // selected target (-keypool)
         int64_t missingExternal = std::max<int64_t>(
             std::max<int64_t>(nTargetSize, 1) - setExternalKeyPool.size(), 0);
         int64_t missingInternal = std::max<int64_t>(
             std::max<int64_t>(nTargetSize, 1) - setInternalKeyPool.size(), 0);
 
         if (!IsHDEnabled() || !CanSupportFeature(FEATURE_HD_SPLIT)) {
             // don't create extra internal keys
             missingInternal = 0;
         }
         bool internal = false;
         WalletBatch batch(*database);
         for (int64_t i = missingInternal + missingExternal; i--;) {
             if (i < missingInternal) {
                 internal = true;
             }
 
             // How in the hell did you use so many keys?
             assert(m_max_keypool_index < std::numeric_limits<int64_t>::max());
             int64_t index = ++m_max_keypool_index;
 
             CPubKey pubkey(GenerateNewKey(batch, internal));
             if (!batch.WritePool(index, CKeyPool(pubkey, internal))) {
                 throw std::runtime_error(std::string(__func__) +
                                          ": writing generated key failed");
             }
 
             if (internal) {
                 setInternalKeyPool.insert(index);
             } else {
                 setExternalKeyPool.insert(index);
             }
             m_pool_key_to_index[pubkey.GetID()] = index;
         }
         if (missingInternal + missingExternal > 0) {
             WalletLogPrintf(
                 "keypool added %d keys (%d internal), size=%u (%u internal)\n",
                 missingInternal + missingExternal, missingInternal,
                 setInternalKeyPool.size() + setExternalKeyPool.size() +
                     set_pre_split_keypool.size(),
                 setInternalKeyPool.size());
         }
     }
     NotifyCanGetAddressesChanged();
     return true;
 }
 
 bool CWallet::ReserveKeyFromKeyPool(int64_t &nIndex, CKeyPool &keypool,
                                     bool fRequestedInternal) {
     nIndex = -1;
     keypool.vchPubKey = CPubKey();
     {
         LOCK(cs_wallet);
 
         if (!IsLocked()) {
             TopUpKeyPool();
         }
 
         bool fReturningInternal = IsHDEnabled() &&
                                   CanSupportFeature(FEATURE_HD_SPLIT) &&
                                   fRequestedInternal;
         bool use_split_keypool = set_pre_split_keypool.empty();
         std::set<int64_t> &setKeyPool =
             use_split_keypool
                 ? (fReturningInternal ? setInternalKeyPool : setExternalKeyPool)
                 : set_pre_split_keypool;
 
         // Get the oldest key
         if (setKeyPool.empty()) {
             return false;
         }
 
         WalletBatch batch(*database);
 
         auto it = setKeyPool.begin();
         nIndex = *it;
         setKeyPool.erase(it);
         if (!batch.ReadPool(nIndex, keypool)) {
             throw std::runtime_error(std::string(__func__) + ": read failed");
         }
         if (!HaveKey(keypool.vchPubKey.GetID())) {
             throw std::runtime_error(std::string(__func__) +
                                      ": unknown key in key pool");
         }
         // If the key was pre-split keypool, we don't care about what type it is
         if (use_split_keypool && keypool.fInternal != fReturningInternal) {
             throw std::runtime_error(std::string(__func__) +
                                      ": keypool entry misclassified");
         }
         if (!keypool.vchPubKey.IsValid()) {
             throw std::runtime_error(std::string(__func__) +
                                      ": keypool entry invalid");
         }
 
         m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
         WalletLogPrintf("keypool reserve %d\n", nIndex);
     }
     NotifyCanGetAddressesChanged();
     return true;
 }
 
 void CWallet::KeepKey(int64_t nIndex) {
     // Remove from key pool.
     WalletBatch batch(*database);
     batch.ErasePool(nIndex);
     WalletLogPrintf("keypool keep %d\n", nIndex);
 }
 
 void CWallet::ReturnKey(int64_t nIndex, bool fInternal, const CPubKey &pubkey) {
     // Return to key pool
     {
         LOCK(cs_wallet);
         if (fInternal) {
             setInternalKeyPool.insert(nIndex);
         } else if (!set_pre_split_keypool.empty()) {
             set_pre_split_keypool.insert(nIndex);
         } else {
             setExternalKeyPool.insert(nIndex);
         }
         m_pool_key_to_index[pubkey.GetID()] = nIndex;
         NotifyCanGetAddressesChanged();
     }
 
     WalletLogPrintf("keypool return %d\n", nIndex);
 }
 
 bool CWallet::GetKeyFromPool(CPubKey &result, bool internal) {
     if (!CanGetAddresses(internal)) {
         return false;
     }
 
     CKeyPool keypool;
     LOCK(cs_wallet);
     int64_t nIndex;
     if (!ReserveKeyFromKeyPool(nIndex, keypool, internal)) {
         if (IsLocked()) {
             return false;
         }
         WalletBatch batch(*database);
         result = GenerateNewKey(batch, internal);
         return true;
     }
 
     KeepKey(nIndex);
     result = keypool.vchPubKey;
 
     return true;
 }
 
 static int64_t GetOldestKeyTimeInPool(const std::set<int64_t> &setKeyPool,
                                       WalletBatch &batch) {
     if (setKeyPool.empty()) {
         return GetTime();
     }
 
     CKeyPool keypool;
     int64_t nIndex = *(setKeyPool.begin());
     if (!batch.ReadPool(nIndex, keypool)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": read oldest key in keypool failed");
     }
 
     assert(keypool.vchPubKey.IsValid());
     return keypool.nTime;
 }
 
 int64_t CWallet::GetOldestKeyPoolTime() {
     LOCK(cs_wallet);
 
     WalletBatch batch(*database);
 
     // load oldest key from keypool, get time and return
     int64_t oldestKey = GetOldestKeyTimeInPool(setExternalKeyPool, batch);
     if (IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT)) {
         oldestKey = std::max(GetOldestKeyTimeInPool(setInternalKeyPool, batch),
                              oldestKey);
         if (!set_pre_split_keypool.empty()) {
             oldestKey =
                 std::max(GetOldestKeyTimeInPool(set_pre_split_keypool, batch),
                          oldestKey);
         }
     }
 
     return oldestKey;
 }
 
 std::map<CTxDestination, Amount>
 CWallet::GetAddressBalances(interfaces::Chain::Lock &locked_chain) {
     std::map<CTxDestination, Amount> balances;
 
     LOCK(cs_wallet);
     for (const auto &walletEntry : mapWallet) {
         const CWalletTx *pcoin = &walletEntry.second;
 
         if (!pcoin->IsTrusted(locked_chain)) {
             continue;
         }
 
         if (pcoin->IsImmatureCoinBase(locked_chain)) {
             continue;
         }
 
         int nDepth = pcoin->GetDepthInMainChain(locked_chain);
         if (nDepth < (pcoin->IsFromMe(ISMINE_ALL) ? 0 : 1)) {
             continue;
         }
 
         for (uint32_t i = 0; i < pcoin->tx->vout.size(); i++) {
             CTxDestination addr;
             if (!IsMine(pcoin->tx->vout[i])) {
                 continue;
             }
 
             if (!ExtractDestination(pcoin->tx->vout[i].scriptPubKey, addr)) {
                 continue;
             }
 
             Amount n = IsSpent(locked_chain, COutPoint(walletEntry.first, i))
                            ? Amount::zero()
                            : pcoin->tx->vout[i].nValue;
 
             if (!balances.count(addr)) {
                 balances[addr] = Amount::zero();
             }
             balances[addr] += n;
         }
     }
 
     return balances;
 }
 
 std::set<std::set<CTxDestination>> CWallet::GetAddressGroupings() {
     // mapWallet
     AssertLockHeld(cs_wallet);
     std::set<std::set<CTxDestination>> groupings;
     std::set<CTxDestination> grouping;
 
     for (const auto &walletEntry : mapWallet) {
         const CWalletTx *pcoin = &walletEntry.second;
 
         if (pcoin->tx->vin.size() > 0) {
             bool any_mine = false;
             // Group all input addresses with each other.
             for (const auto &txin : pcoin->tx->vin) {
                 CTxDestination address;
                 // If this input isn't mine, ignore it.
                 if (!IsMine(txin)) {
                     continue;
                 }
 
                 if (!ExtractDestination(mapWallet.at(txin.prevout.GetTxId())
                                             .tx->vout[txin.prevout.GetN()]
                                             .scriptPubKey,
                                         address)) {
                     continue;
                 }
 
                 grouping.insert(address);
                 any_mine = true;
             }
 
             // Group change with input addresses.
             if (any_mine) {
                 for (const auto &txout : pcoin->tx->vout) {
                     if (IsChange(txout)) {
                         CTxDestination txoutAddr;
                         if (!ExtractDestination(txout.scriptPubKey,
                                                 txoutAddr)) {
                             continue;
                         }
 
                         grouping.insert(txoutAddr);
                     }
                 }
             }
 
             if (grouping.size() > 0) {
                 groupings.insert(grouping);
                 grouping.clear();
             }
         }
 
         // Group lone addrs by themselves.
         for (const auto &txout : pcoin->tx->vout) {
             if (IsMine(txout)) {
                 CTxDestination address;
                 if (!ExtractDestination(txout.scriptPubKey, address)) {
                     continue;
                 }
 
                 grouping.insert(address);
                 groupings.insert(grouping);
                 grouping.clear();
             }
         }
     }
 
     // A set of pointers to groups of addresses.
     std::set<std::set<CTxDestination> *> uniqueGroupings;
     // Map addresses to the unique group containing it.
     std::map<CTxDestination, std::set<CTxDestination> *> setmap;
     for (std::set<CTxDestination> _grouping : groupings) {
         // Make a set of all the groups hit by this new group.
         std::set<std::set<CTxDestination> *> hits;
         std::map<CTxDestination, std::set<CTxDestination> *>::iterator it;
         for (const CTxDestination &address : _grouping) {
             if ((it = setmap.find(address)) != setmap.end()) {
                 hits.insert((*it).second);
             }
         }
 
         // Merge all hit groups into a new single group and delete old groups.
         std::set<CTxDestination> *merged =
             new std::set<CTxDestination>(_grouping);
         for (std::set<CTxDestination> *hit : hits) {
             merged->insert(hit->begin(), hit->end());
             uniqueGroupings.erase(hit);
             delete hit;
         }
         uniqueGroupings.insert(merged);
 
         // Update setmap.
         for (const CTxDestination &element : *merged) {
             setmap[element] = merged;
         }
     }
 
     std::set<std::set<CTxDestination>> ret;
     for (const std::set<CTxDestination> *uniqueGrouping : uniqueGroupings) {
         ret.insert(*uniqueGrouping);
         delete uniqueGrouping;
     }
 
     return ret;
 }
 
 std::set<CTxDestination>
 CWallet::GetLabelAddresses(const std::string &label) const {
     LOCK(cs_wallet);
     std::set<CTxDestination> result;
     for (const std::pair<const CTxDestination, CAddressBookData> &item :
          mapAddressBook) {
         const CTxDestination &address = item.first;
         const std::string &strName = item.second.name;
         if (strName == label) {
             result.insert(address);
         }
     }
 
     return result;
 }
 
 bool CReserveKey::GetReservedKey(CPubKey &pubkey, bool internal) {
     if (!pwallet->CanGetAddresses(internal)) {
         return false;
     }
 
     if (nIndex == -1) {
         CKeyPool keypool;
         if (!pwallet->ReserveKeyFromKeyPool(nIndex, keypool, internal)) {
             return false;
         }
 
         vchPubKey = keypool.vchPubKey;
         fInternal = keypool.fInternal;
     }
 
     assert(vchPubKey.IsValid());
     pubkey = vchPubKey;
     return true;
 }
 
 void CReserveKey::KeepKey() {
     if (nIndex != -1) {
         pwallet->KeepKey(nIndex);
     }
 
     nIndex = -1;
     vchPubKey = CPubKey();
 }
 
 void CReserveKey::ReturnKey() {
     if (nIndex != -1) {
         pwallet->ReturnKey(nIndex, fInternal, vchPubKey);
     }
     nIndex = -1;
     vchPubKey = CPubKey();
 }
 
 void CWallet::MarkReserveKeysAsUsed(int64_t keypool_id) {
     AssertLockHeld(cs_wallet);
     bool internal = setInternalKeyPool.count(keypool_id);
     if (!internal) {
         assert(setExternalKeyPool.count(keypool_id) ||
                set_pre_split_keypool.count(keypool_id));
     }
 
     std::set<int64_t> *setKeyPool =
         internal ? &setInternalKeyPool
                  : (set_pre_split_keypool.empty() ? &setExternalKeyPool
                                                   : &set_pre_split_keypool);
     auto it = setKeyPool->begin();
 
     WalletBatch batch(*database);
     while (it != std::end(*setKeyPool)) {
         const int64_t &index = *(it);
         if (index > keypool_id) {
             // set*KeyPool is ordered
             break;
         }
 
         CKeyPool keypool;
         if (batch.ReadPool(index, keypool)) {
             // TODO: This should be unnecessary
             m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
         }
         LearnAllRelatedScripts(keypool.vchPubKey);
         batch.ErasePool(index);
         WalletLogPrintf("keypool index %d removed\n", index);
         it = setKeyPool->erase(it);
     }
 }
 
 void CWallet::GetScriptForMining(std::shared_ptr<CReserveScript> &script) {
     std::shared_ptr<CReserveKey> rKey = std::make_shared<CReserveKey>(this);
     CPubKey pubkey;
     if (!rKey->GetReservedKey(pubkey)) {
         return;
     }
 
     script = rKey;
     script->reserveScript = CScript() << ToByteVector(pubkey) << OP_CHECKSIG;
 }
 
 void CWallet::LockCoin(const COutPoint &output) {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
     setLockedCoins.insert(output);
 }
 
 void CWallet::UnlockCoin(const COutPoint &output) {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
     setLockedCoins.erase(output);
 }
 
 void CWallet::UnlockAllCoins() {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
     setLockedCoins.clear();
 }
 
 bool CWallet::IsLockedCoin(const COutPoint &outpoint) const {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
 
     return setLockedCoins.count(outpoint) > 0;
 }
 
 void CWallet::ListLockedCoins(std::vector<COutPoint> &vOutpts) const {
     // setLockedCoins
     AssertLockHeld(cs_wallet);
     for (COutPoint outpoint : setLockedCoins) {
         vOutpts.push_back(outpoint);
     }
 }
 
 /** @} */ // end of Actions
 
 void CWallet::GetKeyBirthTimes(
     interfaces::Chain::Lock &locked_chain,
     std::map<CTxDestination, int64_t> &mapKeyBirth) const {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
     mapKeyBirth.clear();
 
     // Get birth times for keys with metadata.
     for (const auto &entry : mapKeyMetadata) {
         if (entry.second.nCreateTime) {
             mapKeyBirth[entry.first] = entry.second.nCreateTime;
         }
     }
 
-    // Map in which we'll infer heights of other keys the tip can be
-    // reorganized; use a 144-block safety margin.
-    CBlockIndex *pindexMax =
-        ::ChainActive()[std::max(0, ::ChainActive().Height() - 144)];
-    std::map<CKeyID, CBlockIndex *> mapKeyFirstBlock;
+    // Map in which we'll infer heights of other keys
+    const Optional<int> tip_height = locked_chain.getHeight();
+    // the tip can be reorganized; use a 144-block safety margin
+    const int max_height =
+        tip_height && *tip_height > 144 ? *tip_height - 144 : 0;
+    std::map<CKeyID, int> mapKeyFirstBlock;
     for (const CKeyID &keyid : GetKeys()) {
         if (mapKeyBirth.count(keyid) == 0) {
-            mapKeyFirstBlock[keyid] = pindexMax;
+            mapKeyFirstBlock[keyid] = max_height;
         }
     }
 
     // If there are no such keys, we're done.
     if (mapKeyFirstBlock.empty()) {
         return;
     }
 
     // Find first block that affects those keys, if there are any left.
     std::vector<CKeyID> vAffected;
     for (const auto &entry : mapWallet) {
         // iterate over all wallet transactions...
         const CWalletTx &wtx = entry.second;
-        CBlockIndex *pindex = LookupBlockIndex(wtx.hashBlock);
-        if (pindex && ::ChainActive().Contains(pindex)) {
+        if (Optional<int> height = locked_chain.getBlockHeight(wtx.hashBlock)) {
             // ... which are already in a block
-            int nHeight = pindex->nHeight;
             for (const CTxOut &txout : wtx.tx->vout) {
                 // Iterate over all their outputs...
                 CAffectedKeysVisitor(*this, vAffected)
                     .Process(txout.scriptPubKey);
                 for (const CKeyID &keyid : vAffected) {
                     // ... and all their affected keys.
-                    std::map<CKeyID, CBlockIndex *>::iterator rit =
+                    std::map<CKeyID, int>::iterator rit =
                         mapKeyFirstBlock.find(keyid);
                     if (rit != mapKeyFirstBlock.end() &&
-                        nHeight < rit->second->nHeight) {
-                        rit->second = pindex;
+                        *height < rit->second) {
+                        rit->second = *height;
                     }
                 }
                 vAffected.clear();
             }
         }
     }
 
     // Extract block timestamps for those keys.
     for (const auto &entry : mapKeyFirstBlock) {
         // block times can be 2h off
         mapKeyBirth[entry.first] =
-            entry.second->GetBlockTime() - TIMESTAMP_WINDOW;
+            locked_chain.getBlockTime(entry.second) - TIMESTAMP_WINDOW;
     }
 }
 
 /**
  * Compute smart timestamp for a transaction being added to the wallet.
  *
  * Logic:
  * - If sending a transaction, assign its timestamp to the current time.
  * - If receiving a transaction outside a block, assign its timestamp to the
  *   current time.
  * - If receiving a block with a future timestamp, assign all its (not already
  *   known) transactions' timestamps to the current time.
  * - If receiving a block with a past timestamp, before the most recent known
  *   transaction (that we care about), assign all its (not already known)
  *   transactions' timestamps to the same timestamp as that most-recent-known
  *   transaction.
  * - If receiving a block with a past timestamp, but after the most recent known
  *   transaction, assign all its (not already known) transactions' timestamps to
  *   the block time.
  *
  * For more information see CWalletTx::nTimeSmart,
  * https://bitcointalk.org/?topic=54527, or
  * https://github.com/bitcoin/bitcoin/pull/1393.
  */
 unsigned int CWallet::ComputeTimeSmart(const CWalletTx &wtx) const {
     unsigned int nTimeSmart = wtx.nTimeReceived;
     if (!wtx.hashUnset()) {
-        if (const CBlockIndex *pindex = LookupBlockIndex(wtx.hashBlock)) {
+        int64_t blocktime;
+        if (chain().findBlock(wtx.hashBlock, nullptr /* block */, &blocktime)) {
             int64_t latestNow = wtx.nTimeReceived;
             int64_t latestEntry = 0;
 
             // Tolerate times up to the last timestamp in the wallet not more
             // than 5 minutes into the future
             int64_t latestTolerated = latestNow + 300;
             const TxItems &txOrdered = wtxOrdered;
             for (auto it = txOrdered.rbegin(); it != txOrdered.rend(); ++it) {
                 CWalletTx *const pwtx = it->second;
                 if (pwtx == &wtx) {
                     continue;
                 }
                 int64_t nSmartTime;
                 nSmartTime = pwtx->nTimeSmart;
                 if (!nSmartTime) {
                     nSmartTime = pwtx->nTimeReceived;
                 }
                 if (nSmartTime <= latestTolerated) {
                     latestEntry = nSmartTime;
                     if (nSmartTime > latestNow) {
                         latestNow = nSmartTime;
                     }
                     break;
                 }
             }
 
-            int64_t blocktime = pindex->GetBlockTime();
             nTimeSmart = std::max(latestEntry, std::min(blocktime, latestNow));
         } else {
             WalletLogPrintf("%s: found %s in block %s not in index\n", __func__,
                             wtx.GetId().ToString(), wtx.hashBlock.ToString());
         }
     }
     return nTimeSmart;
 }
 
 bool CWallet::AddDestData(const CTxDestination &dest, const std::string &key,
                           const std::string &value) {
     if (boost::get<CNoDestination>(&dest)) {
         return false;
     }
 
     mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
     return WalletBatch(*database).WriteDestData(dest, key, value);
 }
 
 bool CWallet::EraseDestData(const CTxDestination &dest,
                             const std::string &key) {
     if (!mapAddressBook[dest].destdata.erase(key)) {
         return false;
     }
 
     return WalletBatch(*database).EraseDestData(dest, key);
 }
 
 void CWallet::LoadDestData(const CTxDestination &dest, const std::string &key,
                            const std::string &value) {
     mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
 }
 
 bool CWallet::GetDestData(const CTxDestination &dest, const std::string &key,
                           std::string *value) const {
     std::map<CTxDestination, CAddressBookData>::const_iterator i =
         mapAddressBook.find(dest);
     if (i != mapAddressBook.end()) {
         CAddressBookData::StringMap::const_iterator j =
             i->second.destdata.find(key);
         if (j != i->second.destdata.end()) {
             if (value) {
                 *value = j->second;
             }
 
             return true;
         }
     }
     return false;
 }
 
 std::vector<std::string>
 CWallet::GetDestValues(const std::string &prefix) const {
     LOCK(cs_wallet);
     std::vector<std::string> values;
     for (const auto &address : mapAddressBook) {
         for (const auto &data : address.second.destdata) {
             if (!data.first.compare(0, prefix.size(), prefix)) {
                 values.emplace_back(data.second);
             }
         }
     }
     return values;
 }
 
 bool CWallet::Verify(const CChainParams &chainParams, interfaces::Chain &chain,
                      const WalletLocation &location, bool salvage_wallet,
                      std::string &error_string, std::string &warning_string) {
     // Do some checking on wallet path. It should be either a:
     //
     // 1. Path where a directory can be created.
     // 2. Path to an existing directory.
     // 3. Path to a symlink to a directory.
     // 4. For backwards compatibility, the name of a data file in -walletdir.
     LOCK(cs_wallets);
     const fs::path &wallet_path = location.GetPath();
     fs::file_type path_type = fs::symlink_status(wallet_path).type();
     if (!(path_type == fs::file_not_found || path_type == fs::directory_file ||
           (path_type == fs::symlink_file && fs::is_directory(wallet_path)) ||
           (path_type == fs::regular_file &&
            fs::path(location.GetName()).filename() == location.GetName()))) {
         error_string =
             strprintf("Invalid -wallet path '%s'. -wallet path should point to "
                       "a directory where wallet.dat and "
                       "database/log.?????????? files can be stored, a location "
                       "where such a directory could be created, "
                       "or (for backwards compatibility) the name of an "
                       "existing data file in -walletdir (%s)",
                       location.GetName(), GetWalletDir());
         return false;
     }
 
     // Make sure that the wallet path doesn't clash with an existing wallet path
     if (IsWalletLoaded(wallet_path)) {
         error_string = strprintf(
             "Error loading wallet %s. Duplicate -wallet filename specified.",
             location.GetName());
         return false;
     }
 
     // Keep same database environment instance across Verify/Recover calls
     // below.
     std::unique_ptr<WalletDatabase> database =
         WalletDatabase::Create(wallet_path);
 
     try {
         if (!WalletBatch::VerifyEnvironment(wallet_path, error_string)) {
             return false;
         }
     } catch (const fs::filesystem_error &e) {
         error_string =
             strprintf("Error loading wallet %s. %s", location.GetName(),
                       fsbridge::get_filesystem_error_message(e));
         return false;
     }
 
     if (salvage_wallet) {
         // Recover readable keypairs:
         CWallet dummyWallet(chainParams, chain, WalletLocation(),
                             WalletDatabase::CreateDummy());
         std::string backup_filename;
         if (!WalletBatch::Recover(
                 wallet_path, static_cast<void *>(&dummyWallet),
                 WalletBatch::RecoverKeysOnlyFilter, backup_filename)) {
             return false;
         }
     }
 
     return WalletBatch::VerifyDatabaseFile(wallet_path, warning_string,
                                            error_string);
 }
 
 void CWallet::MarkPreSplitKeys() {
     WalletBatch batch(*database);
     for (auto it = setExternalKeyPool.begin();
          it != setExternalKeyPool.end();) {
         int64_t index = *it;
         CKeyPool keypool;
         if (!batch.ReadPool(index, keypool)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": read keypool entry failed");
         }
         keypool.m_pre_split = true;
         if (!batch.WritePool(index, keypool)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": writing modified keypool entry failed");
         }
         set_pre_split_keypool.insert(index);
         it = setExternalKeyPool.erase(it);
     }
 }
 
 std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(
     const CChainParams &chainParams, interfaces::Chain &chain,
     const WalletLocation &location, uint64_t wallet_creation_flags) {
     const std::string &walletFile = location.GetName();
 
     // Needed to restore wallet transaction meta data after -zapwallettxes
     std::vector<CWalletTx> vWtx;
 
     if (gArgs.GetBoolArg("-zapwallettxes", false)) {
         uiInterface.InitMessage(_("Zapping all transactions from wallet..."));
 
         std::unique_ptr<CWallet> tempWallet = std::make_unique<CWallet>(
             chainParams, chain, location,
             WalletDatabase::Create(location.GetPath()));
         DBErrors nZapWalletRet = tempWallet->ZapWalletTx(vWtx);
         if (nZapWalletRet != DBErrors::LOAD_OK) {
             InitError(
                 strprintf(_("Error loading %s: Wallet corrupted"), walletFile));
             return nullptr;
         }
     }
 
     uiInterface.InitMessage(_("Loading wallet..."));
 
     int64_t nStart = GetTimeMillis();
     bool fFirstRun = true;
     // TODO: Can't use std::make_shared because we need a custom deleter but
     // should be possible to use std::allocate_shared.
     std::shared_ptr<CWallet> walletInstance(
         new CWallet(chainParams, chain, location,
                     WalletDatabase::Create(location.GetPath())),
         ReleaseWallet);
     DBErrors nLoadWalletRet = walletInstance->LoadWallet(fFirstRun);
     if (nLoadWalletRet != DBErrors::LOAD_OK) {
         if (nLoadWalletRet == DBErrors::CORRUPT) {
             InitError(
                 strprintf(_("Error loading %s: Wallet corrupted"), walletFile));
             return nullptr;
         }
 
         if (nLoadWalletRet == DBErrors::NONCRITICAL_ERROR) {
             InitWarning(strprintf(
                 _("Error reading %s! All keys read correctly, but transaction "
                   "data"
                   " or address book entries might be missing or incorrect."),
                 walletFile));
         } else if (nLoadWalletRet == DBErrors::TOO_NEW) {
             InitError(strprintf(
                 _("Error loading %s: Wallet requires newer version of %s"),
                 walletFile, _(PACKAGE_NAME)));
             return nullptr;
         } else if (nLoadWalletRet == DBErrors::NEED_REWRITE) {
             InitError(strprintf(
                 _("Wallet needed to be rewritten: restart %s to complete"),
                 _(PACKAGE_NAME)));
             return nullptr;
         } else {
             InitError(strprintf(_("Error loading %s"), walletFile));
             return nullptr;
         }
     }
 
     int prev_version = walletInstance->nWalletVersion;
     if (gArgs.GetBoolArg("-upgradewallet", fFirstRun)) {
         int nMaxVersion = gArgs.GetArg("-upgradewallet", 0);
         // The -upgradewallet without argument case
         if (nMaxVersion == 0) {
             walletInstance->WalletLogPrintf("Performing wallet upgrade to %i\n",
                                             FEATURE_LATEST);
             nMaxVersion = FEATURE_LATEST;
             // permanently upgrade the wallet immediately
             walletInstance->SetMinVersion(FEATURE_LATEST);
         } else {
             walletInstance->WalletLogPrintf(
                 "Allowing wallet upgrade up to %i\n", nMaxVersion);
         }
 
         if (nMaxVersion < walletInstance->GetVersion()) {
             InitError(_("Cannot downgrade wallet"));
             return nullptr;
         }
 
         walletInstance->SetMaxVersion(nMaxVersion);
     }
 
     // Upgrade to HD if explicit upgrade
     if (gArgs.GetBoolArg("-upgradewallet", false)) {
         LOCK(walletInstance->cs_wallet);
 
         // Do not upgrade versions to any version between HD_SPLIT and
         // FEATURE_PRE_SPLIT_KEYPOOL unless already supporting HD_SPLIT
         int max_version = walletInstance->nWalletVersion;
         if (!walletInstance->CanSupportFeature(FEATURE_HD_SPLIT) &&
             max_version >= FEATURE_HD_SPLIT &&
             max_version < FEATURE_PRE_SPLIT_KEYPOOL) {
             InitError(
                 _("Cannot upgrade a non HD split wallet without upgrading to "
                   "support pre split keypool. Please use -upgradewallet=200300 "
                   "or -upgradewallet with no version specified."));
             return nullptr;
         }
 
         bool hd_upgrade = false;
         bool split_upgrade = false;
         if (walletInstance->CanSupportFeature(FEATURE_HD) &&
             !walletInstance->IsHDEnabled()) {
             walletInstance->WalletLogPrintf("Upgrading wallet to HD\n");
             walletInstance->SetMinVersion(FEATURE_HD);
 
             // generate a new master key
             CPubKey masterPubKey = walletInstance->GenerateNewSeed();
             walletInstance->SetHDSeed(masterPubKey);
             hd_upgrade = true;
         }
         // Upgrade to HD chain split if necessary
         if (walletInstance->CanSupportFeature(FEATURE_HD_SPLIT)) {
             walletInstance->WalletLogPrintf(
                 "Upgrading wallet to use HD chain split\n");
             walletInstance->SetMinVersion(FEATURE_PRE_SPLIT_KEYPOOL);
             split_upgrade = FEATURE_HD_SPLIT > prev_version;
         }
         // Mark all keys currently in the keypool as pre-split
         if (split_upgrade) {
             walletInstance->MarkPreSplitKeys();
         }
         // Regenerate the keypool if upgraded to HD
         if (hd_upgrade) {
             if (!walletInstance->TopUpKeyPool()) {
                 InitError(_("Unable to generate keys"));
                 return nullptr;
             }
         }
     }
 
     if (fFirstRun) {
         // Ensure this wallet.dat can only be opened by clients supporting
         // HD with chain split and expects no default key.
         walletInstance->SetMinVersion(FEATURE_LATEST);
 
         if ((wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
             // selective allow to set flags
             walletInstance->SetWalletFlag(WALLET_FLAG_DISABLE_PRIVATE_KEYS);
         } else if (wallet_creation_flags & WALLET_FLAG_BLANK_WALLET) {
             walletInstance->SetWalletFlag(WALLET_FLAG_BLANK_WALLET);
         } else {
             // generate a new seed
             CPubKey seed = walletInstance->GenerateNewSeed();
             walletInstance->SetHDSeed(seed);
         } // Otherwise, do not generate a new seed
 
         // Top up the keypool
         if (walletInstance->CanGenerateKeys() &&
             !walletInstance->TopUpKeyPool()) {
             InitError(_("Unable to generate initial keys"));
             return nullptr;
         }
 
         // Temporary. Removed in upcoming lock cleanup
         auto locked_chain = chain.assumeLocked();
-        walletInstance->ChainStateFlushed(::ChainActive().GetLocator());
+        walletInstance->ChainStateFlushed(locked_chain->getLocator());
     } else if (wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS) {
         // Make it impossible to disable private keys after creation
         InitError(strprintf(_("Error loading %s: Private keys can only be "
                               "disabled during creation"),
                             walletFile));
         return nullptr;
     } else if (walletInstance->IsWalletFlagSet(
                    WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         LOCK(walletInstance->cs_KeyStore);
         if (!walletInstance->mapKeys.empty() ||
             !walletInstance->mapCryptedKeys.empty()) {
             InitWarning(strprintf(_("Warning: Private keys detected in wallet "
                                     "{%s} with disabled private keys"),
                                   walletFile));
         }
     }
 
     if (gArgs.IsArgSet("-mintxfee")) {
         Amount n = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-mintxfee", ""), n) ||
             n == Amount::zero()) {
             InitError(AmountErrMsg("mintxfee", gArgs.GetArg("-mintxfee", "")));
             return nullptr;
         }
         if (n > HIGH_TX_FEE_PER_KB) {
             InitWarning(AmountHighWarn("-mintxfee") + " " +
                         _("This is the minimum transaction fee you pay on "
                           "every transaction."));
         }
         walletInstance->m_min_fee = CFeeRate(n);
     }
 
     if (gArgs.IsArgSet("-fallbackfee")) {
         Amount nFeePerK = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-fallbackfee", ""), nFeePerK)) {
             InitError(
                 strprintf(_("Invalid amount for -fallbackfee=<amount>: '%s'"),
                           gArgs.GetArg("-fallbackfee", "")));
             return nullptr;
         }
         if (nFeePerK > HIGH_TX_FEE_PER_KB) {
             InitWarning(AmountHighWarn("-fallbackfee") + " " +
                         _("This is the transaction fee you may pay when fee "
                           "estimates are not available."));
         }
         walletInstance->m_fallback_fee = CFeeRate(nFeePerK);
         // disable fallback fee in case value was set to 0, enable if non-null
         // value
         walletInstance->m_allow_fallback_fee = (nFeePerK != Amount::zero());
     }
     if (gArgs.IsArgSet("-paytxfee")) {
         Amount nFeePerK = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-paytxfee", ""), nFeePerK)) {
             InitError(AmountErrMsg("paytxfee", gArgs.GetArg("-paytxfee", "")));
             return nullptr;
         }
         if (nFeePerK > HIGH_TX_FEE_PER_KB) {
             InitWarning(AmountHighWarn("-paytxfee") + " " +
                         _("This is the transaction fee you will pay if you "
                           "send a transaction."));
         }
         walletInstance->m_pay_tx_fee = CFeeRate(nFeePerK, 1000);
         if (walletInstance->m_pay_tx_fee < ::minRelayTxFee) {
             InitError(strprintf(_("Invalid amount for -paytxfee=<amount>: '%s' "
                                   "(must be at least %s)"),
                                 gArgs.GetArg("-paytxfee", ""),
                                 ::minRelayTxFee.ToString()));
             return nullptr;
         }
     }
     walletInstance->m_spend_zero_conf_change =
         gArgs.GetBoolArg("-spendzeroconfchange", DEFAULT_SPEND_ZEROCONF_CHANGE);
 
     walletInstance->m_default_address_type = DEFAULT_ADDRESS_TYPE;
     walletInstance->m_default_change_type = DEFAULT_CHANGE_TYPE;
 
     walletInstance->WalletLogPrintf("Wallet completed loading in %15dms\n",
                                     GetTimeMillis() - nStart);
 
     // Try to top up keypool. No-op if the wallet is locked.
     walletInstance->TopUpKeyPool();
 
-    // Temporary, for FindForkInGlobalIndex below. Removed in upcoming commit.
-    LockAnnotation lock(::cs_main);
     auto locked_chain = chain.lock();
     LOCK(walletInstance->cs_wallet);
 
-    CBlockIndex *pindexRescan = ::ChainActive().Genesis();
+    int rescan_height = 0;
     if (!gArgs.GetBoolArg("-rescan", false)) {
         WalletBatch batch(*walletInstance->database);
         CBlockLocator locator;
         if (batch.ReadBestBlock(locator)) {
-            pindexRescan = FindForkInGlobalIndex(::ChainActive(), locator);
+            if (const Optional<int> fork_height =
+                    locked_chain->findLocatorFork(locator)) {
+                rescan_height = *fork_height;
+            }
         }
     }
 
-    walletInstance->m_last_block_processed = ::ChainActive().Tip();
+    const Optional<int> tip_height = locked_chain->getHeight();
+    if (tip_height) {
+        walletInstance->m_last_block_processed =
+            locked_chain->getBlockHash(*tip_height);
+    } else {
+        walletInstance->m_last_block_processed.SetNull();
+    }
 
-    if (::ChainActive().Tip() && ::ChainActive().Tip() != pindexRescan) {
+    if (tip_height && *tip_height != rescan_height) {
         // We can't rescan beyond non-pruned blocks, stop and throw an error.
         // This might happen if a user uses an old wallet within a pruned node
         // or if he ran -disablewallet for a longer time, then decided to
         // re-enable.
         if (fPruneMode) {
-            CBlockIndex *block = ::ChainActive().Tip();
-            while (block && block->pprev && block->pprev->nStatus.hasData() &&
-                   block->pprev->nTx > 0 && pindexRescan != block) {
-                block = block->pprev;
+            int block_height = *tip_height;
+            while (block_height > 0 &&
+                   locked_chain->haveBlockOnDisk(block_height - 1) &&
+                   rescan_height != block_height) {
+                --block_height;
             }
 
-            if (pindexRescan != block) {
+            if (rescan_height != block_height) {
                 InitError(_("Prune: last wallet synchronisation goes beyond "
                             "pruned data. You need to -reindex (download the "
                             "whole blockchain again in case of pruned node)"));
                 return nullptr;
             }
         }
 
         uiInterface.InitMessage(_("Rescanning..."));
         walletInstance->WalletLogPrintf(
             "Rescanning last %i blocks (from block %i)...\n",
-            ::ChainActive().Height() - pindexRescan->nHeight,
-            pindexRescan->nHeight);
+            *tip_height - rescan_height, rescan_height);
 
         // No need to read and scan block if block was created before our wallet
         // birthday (as adjusted for block time variability)
-        while (pindexRescan && walletInstance->nTimeFirstKey &&
-               (pindexRescan->GetBlockTime() <
-                (walletInstance->nTimeFirstKey - TIMESTAMP_WINDOW))) {
-            pindexRescan = ::ChainActive().Next(pindexRescan);
+        if (walletInstance->nTimeFirstKey) {
+            if (Optional<int> first_block =
+                    locked_chain->findFirstBlockWithTimeAndHeight(
+                        walletInstance->nTimeFirstKey - TIMESTAMP_WINDOW,
+                        rescan_height)) {
+                rescan_height = *first_block;
+            }
         }
 
         nStart = GetTimeMillis();
         {
             WalletRescanReserver reserver(walletInstance.get());
-            const CBlockIndex *stop_block, *failed_block;
             if (!reserver.reserve() ||
                 (ScanResult::SUCCESS !=
-                 walletInstance->ScanForWalletTransactions(
-                     pindexRescan, nullptr, reserver, failed_block, stop_block,
-                     true))) {
+                 walletInstance
+                     ->ScanForWalletTransactions(
+                         locked_chain->getBlockHash(rescan_height), BlockHash(),
+                         reserver, true /* update */)
+                     .status)) {
                 InitError(
                     _("Failed to rescan the wallet during initialization"));
                 return nullptr;
             }
         }
         walletInstance->WalletLogPrintf("Rescan completed in %15dms\n",
                                         GetTimeMillis() - nStart);
-        walletInstance->ChainStateFlushed(::ChainActive().GetLocator());
+        walletInstance->ChainStateFlushed(locked_chain->getLocator());
         walletInstance->database->IncrementUpdateCounter();
 
         // Restore wallet transaction metadata after -zapwallettxes=1
         if (gArgs.GetBoolArg("-zapwallettxes", false) &&
             gArgs.GetArg("-zapwallettxes", "1") != "2") {
             WalletBatch batch(*walletInstance->database);
 
             for (const CWalletTx &wtxOld : vWtx) {
                 const TxId txid = wtxOld.GetId();
                 std::map<TxId, CWalletTx>::iterator mi =
                     walletInstance->mapWallet.find(txid);
                 if (mi != walletInstance->mapWallet.end()) {
                     const CWalletTx *copyFrom = &wtxOld;
                     CWalletTx *copyTo = &mi->second;
                     copyTo->mapValue = copyFrom->mapValue;
                     copyTo->vOrderForm = copyFrom->vOrderForm;
                     copyTo->nTimeReceived = copyFrom->nTimeReceived;
                     copyTo->nTimeSmart = copyFrom->nTimeSmart;
                     copyTo->fFromMe = copyFrom->fFromMe;
                     copyTo->nOrderPos = copyFrom->nOrderPos;
                     batch.WriteTx(*copyTo);
                 }
             }
         }
     }
 
     uiInterface.LoadWallet(walletInstance);
 
     // Register with the validation interface. It's ok to do this after rescan
     // since we're still holding cs_main.
     RegisterValidationInterface(walletInstance.get());
 
     walletInstance->SetBroadcastTransactions(
         gArgs.GetBoolArg("-walletbroadcast", DEFAULT_WALLETBROADCAST));
 
     walletInstance->WalletLogPrintf("setKeyPool.size() = %u\n",
                                     walletInstance->GetKeyPoolSize());
     walletInstance->WalletLogPrintf("mapWallet.size() = %u\n",
                                     walletInstance->mapWallet.size());
     walletInstance->WalletLogPrintf("mapAddressBook.size() = %u\n",
                                     walletInstance->mapAddressBook.size());
 
     return walletInstance;
 }
 
 void CWallet::postInitProcess() {
     // Add wallet transactions that aren't already in a block to mempool.
     // Do this here as mempool requires genesis block to be loaded.
     ReacceptWalletTransactions();
 }
 
 bool CWallet::BackupWallet(const std::string &strDest) {
     return database->Backup(strDest);
 }
 
 CKeyPool::CKeyPool() {
     nTime = GetTime();
     fInternal = false;
     m_pre_split = false;
 }
 
 CKeyPool::CKeyPool(const CPubKey &vchPubKeyIn, bool internalIn) {
     nTime = GetTime();
     vchPubKey = vchPubKeyIn;
     fInternal = internalIn;
     m_pre_split = false;
 }
 
 CWalletKey::CWalletKey(int64_t nExpires) {
     nTimeCreated = (nExpires ? GetTime() : 0);
     nTimeExpires = nExpires;
 }
 
-void CMerkleTx::SetMerkleBranch(const CBlockIndex *pindex, int posInBlock) {
+void CMerkleTx::SetMerkleBranch(const BlockHash &block_hash, int posInBlock) {
     // Update the tx's hashBlock
-    hashBlock = pindex->GetBlockHash();
+    hashBlock = block_hash;
 
     // Set the position of the transaction in the block.
     nIndex = posInBlock;
 }
 
 int CMerkleTx::GetDepthInMainChain(
     interfaces::Chain::Lock &locked_chain) const {
     if (hashUnset()) {
         return 0;
     }
 
     AssertLockHeld(cs_main);
 
-    // Find the block it claims to be in.
-    CBlockIndex *pindex = LookupBlockIndex(hashBlock);
-    if (!pindex || !::ChainActive().Contains(pindex)) {
-        return 0;
-    }
-
-    return ((nIndex == -1) ? (-1) : 1) *
-           (::ChainActive().Height() - pindex->nHeight + 1);
+    return locked_chain.getBlockDepth(hashBlock) * (nIndex == -1 ? -1 : 1);
 }
 
 int CMerkleTx::GetBlocksToMaturity(
     interfaces::Chain::Lock &locked_chain) const {
     if (!IsCoinBase()) {
         return 0;
     }
 
     return std::max(0, (COINBASE_MATURITY + 1) -
                            GetDepthInMainChain(locked_chain));
 }
 
 bool CMerkleTx::IsImmatureCoinBase(
     interfaces::Chain::Lock &locked_chain) const {
     // note GetBlocksToMaturity is 0 for non-coinbase tx
     return GetBlocksToMaturity(locked_chain) > 0;
 }
 
 bool CWalletTx::AcceptToMemoryPool(interfaces::Chain::Lock &locked_chain,
                                    const Amount nAbsurdFee,
                                    CValidationState &state) {
     // Temporary, for AcceptToMemoryPool below. Removed in upcoming commit.
     LockAnnotation lock(::cs_main);
 
     // We must set fInMempool here - while it will be re-set to true by the
     // entered-mempool callback, if we did not there would be a race where a
     // user could call sendmoney in a loop and hit spurious out of funds errors
     // because we think that this newly generated transaction's change is
     // unavailable as we're not yet aware that it is in the mempool.
     bool ret = ::AcceptToMemoryPool(GetConfig(), g_mempool, state, tx,
                                     nullptr /* pfMissingInputs */,
                                     false /* bypass_limits */, nAbsurdFee);
     fInMempool |= ret;
     return ret;
 }
 
 void CWallet::LearnRelatedScripts(const CPubKey &key, OutputType type) {
     // Nothing to do...
 }
 
 void CWallet::LearnAllRelatedScripts(const CPubKey &key) {
     // Nothing to do...
 }
 
 std::vector<OutputGroup>
 CWallet::GroupOutputs(const std::vector<COutput> &outputs,
                       bool single_coin) const {
     std::vector<OutputGroup> groups;
     std::map<CTxDestination, OutputGroup> gmap;
     CTxDestination dst;
     for (const auto &output : outputs) {
         if (output.fSpendable) {
             CInputCoin input_coin = output.GetInputCoin();
 
             size_t ancestors, descendants;
             g_mempool.GetTransactionAncestry(output.tx->GetId(), ancestors,
                                              descendants);
             if (!single_coin &&
                 ExtractDestination(output.tx->tx->vout[output.i].scriptPubKey,
                                    dst)) {
                 // Limit output groups to no more than 10 entries, to protect
                 // against inadvertently creating a too-large transaction
                 // when using -avoidpartialspends
                 if (gmap[dst].m_outputs.size() >= OUTPUT_GROUP_MAX_ENTRIES) {
                     groups.push_back(gmap[dst]);
                     gmap.erase(dst);
                 }
                 gmap[dst].Insert(input_coin, output.nDepth,
                                  output.tx->IsFromMe(ISMINE_ALL), ancestors,
                                  descendants);
             } else {
                 groups.emplace_back(input_coin, output.nDepth,
                                     output.tx->IsFromMe(ISMINE_ALL), ancestors,
                                     descendants);
             }
         }
     }
     if (!single_coin) {
         for (const auto &it : gmap) {
             groups.push_back(it.second);
         }
     }
     return groups;
 }
 
 bool CWallet::GetKeyOrigin(const CKeyID &keyID, KeyOriginInfo &info) const {
     CKeyMetadata meta;
     {
         LOCK(cs_wallet);
         auto it = mapKeyMetadata.find(keyID);
         if (it != mapKeyMetadata.end()) {
             meta = it->second;
         }
     }
     if (!meta.hdKeypath.empty()) {
         if (!ParseHDKeypath(meta.hdKeypath, info.path)) {
             return false;
         }
         // Get the proper master key id
         CKey key;
         GetKey(meta.hd_seed_id, key);
         CExtKey masterKey;
         masterKey.SetSeed(key.begin(), key.size());
         // Compute identifier
         CKeyID masterid = masterKey.key.GetPubKey().GetID();
         std::copy(masterid.begin(), masterid.begin() + 4, info.fingerprint);
     } else {
         // Single pubkeys get the master fingerprint of themselves
         std::copy(keyID.begin(), keyID.begin() + 4, info.fingerprint);
     }
     return true;
 }
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index a22ee85bc2..6c144407da 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -1,1507 +1,1515 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Copyright (c) 2018-2020 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_WALLET_WALLET_H
 #define BITCOIN_WALLET_WALLET_H
 
 #include <amount.h>
 #include <interfaces/chain.h>
 #include <outputtype.h>
 #include <primitives/blockhash.h>
 #include <script/ismine.h>
 #include <script/sign.h>
 #include <streams.h>
 #include <tinyformat.h>
 #include <ui_interface.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <validationinterface.h>
 #include <wallet/coinselection.h>
 #include <wallet/crypter.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/walletdb.h>
 #include <wallet/walletutil.h>
 
 #include <algorithm>
 #include <atomic>
 #include <cstdint>
 #include <map>
 #include <memory>
 #include <set>
 #include <stdexcept>
 #include <string>
 #include <utility>
 #include <vector>
 
 //! Responsible for reading and validating the -wallet arguments and verifying
 //! the wallet database.
 //  This function will perform salvage on the wallet if requested, as long as
 //  only one wallet is being loaded (WalletParameterInteraction forbids
 //  -salvagewallet, -zapwallettxes or -upgradewallet with multiwallet).
 bool VerifyWallets(const CChainParams &chainParams, interfaces::Chain &chain,
                    const std::vector<std::string> &wallet_files);
 
 //! Load wallet databases.
 bool LoadWallets(const CChainParams &chainParams, interfaces::Chain &chain,
                  const std::vector<std::string> &wallet_files);
 
 //! Complete startup of wallets.
 void StartWallets(CScheduler &scheduler);
 
 //! Flush all wallets in preparation for shutdown.
 void FlushWallets();
 
 //! Stop all wallets. Wallets will be flushed first.
 void StopWallets();
 
 //! Close all wallets.
 void UnloadWallets();
 
 //! Explicitly unload and delete the wallet.
 //  Blocks the current thread after signaling the unload intent so that all
 //  wallet clients release the wallet.
 //  Note that, when blocking is not required, the wallet is implicitly unloaded
 //  by the shared pointer deleter.
 void UnloadWallet(std::shared_ptr<CWallet> &&wallet);
 
 bool AddWallet(const std::shared_ptr<CWallet> &wallet);
 bool RemoveWallet(const std::shared_ptr<CWallet> &wallet);
 bool HasWallets();
 std::vector<std::shared_ptr<CWallet>> GetWallets();
 std::shared_ptr<CWallet> GetWallet(const std::string &name);
 
 //! Default for -keypool
 static const unsigned int DEFAULT_KEYPOOL_SIZE = 1000;
 //! -paytxfee default
 constexpr Amount DEFAULT_PAY_TX_FEE = Amount::zero();
 //! -fallbackfee default
 static const Amount DEFAULT_FALLBACK_FEE(20000 * SATOSHI);
 //! -mintxfee default
 static const Amount DEFAULT_TRANSACTION_MINFEE_PER_KB = 1000 * SATOSHI;
 //! minimum recommended increment for BIP 125 replacement txs
 static const Amount WALLET_INCREMENTAL_RELAY_FEE(5000 * SATOSHI);
 //! Default for -spendzeroconfchange
 static const bool DEFAULT_SPEND_ZEROCONF_CHANGE = true;
 //! Default for -walletrejectlongchains
 static const bool DEFAULT_WALLET_REJECT_LONG_CHAINS = false;
 //! Default for -avoidpartialspends
 static const bool DEFAULT_AVOIDPARTIALSPENDS = false;
 static const bool DEFAULT_WALLETBROADCAST = true;
 static const bool DEFAULT_DISABLE_WALLET = false;
 
-class CBlockIndex;
 class CChainParams;
 class CCoinControl;
 class COutput;
 class CReserveKey;
 class CScript;
 class CTxMemPool;
 class CWalletTx;
 
 /** (client) version numbers for particular wallet features */
 enum WalletFeature {
     // the earliest version new wallets supports (only useful for
     // getwalletinfo's clientversion output)
     FEATURE_BASE = 10500,
 
     // wallet encryption
     FEATURE_WALLETCRYPT = 40000,
     // compressed public keys
     FEATURE_COMPRPUBKEY = 60000,
 
     // Hierarchical key derivation after BIP32 (HD Wallet)
     FEATURE_HD = 130000,
 
     // Wallet with HD chain split (change outputs will use m/0'/1'/k)
     FEATURE_HD_SPLIT = 160300,
 
     // Wallet without a default key written
     FEATURE_NO_DEFAULT_KEY = 190700,
 
     // Upgraded to HD SPLIT and can have a pre-split keypool
     FEATURE_PRE_SPLIT_KEYPOOL = 200300,
 
     FEATURE_LATEST = FEATURE_PRE_SPLIT_KEYPOOL,
 };
 
 //! Default for -addresstype
 constexpr OutputType DEFAULT_ADDRESS_TYPE{OutputType::LEGACY};
 
 //! Default for -changetype
 constexpr OutputType DEFAULT_CHANGE_TYPE{OutputType::CHANGE_AUTO};
 
 enum WalletFlags : uint64_t {
     // Wallet flags in the upper section (> 1 << 31) will lead to not opening
     // the wallet if flag is unknown.
     // Unknown wallet flags in the lower section <= (1 << 31) will be tolerated.
 
     // Will enforce the rule that the wallet can't contain any private keys
     // (only watch-only/pubkeys).
     WALLET_FLAG_DISABLE_PRIVATE_KEYS = (1ULL << 32),
 
     //! Flag set when a wallet contains no HD seed and no private keys, scripts,
     //! addresses, and other watch only things, and is therefore "blank."
     //!
     //! The only function this flag serves is to distinguish a blank wallet from
     //! a newly created wallet when the wallet database is loaded, to avoid
     //! initialization that should only happen on first run.
     //!
     //! This flag is also a mandatory flag to prevent previous versions of
     //! bitcoin from opening the wallet, thinking it was newly created, and
     //! then improperly reinitializing it.
     WALLET_FLAG_BLANK_WALLET = (1ULL << 33),
 };
 
 static constexpr uint64_t g_known_wallet_flags =
     WALLET_FLAG_DISABLE_PRIVATE_KEYS | WALLET_FLAG_BLANK_WALLET;
 
 /** A key pool entry */
 class CKeyPool {
 public:
     int64_t nTime;
     CPubKey vchPubKey;
     // for change outputs
     bool fInternal;
     // For keys generated before keypool split upgrade
     bool m_pre_split;
 
     CKeyPool();
     CKeyPool(const CPubKey &vchPubKeyIn, bool internalIn);
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         int nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) {
             READWRITE(nVersion);
         }
 
         READWRITE(nTime);
         READWRITE(vchPubKey);
         if (ser_action.ForRead()) {
             try {
                 READWRITE(fInternal);
             } catch (std::ios_base::failure &) {
                 /**
                  * flag as external address if we can't read the internal
                  * boolean (this will be the case for any wallet before the HD
                  * chain split version)
                  */
                 fInternal = false;
             }
             try {
                 READWRITE(m_pre_split);
             } catch (std::ios_base::failure &) {
                 /**
                  * flag as postsplit address if we can't read the m_pre_split
                  * boolean (this will be the case for any wallet that upgrades
                  * to HD chain split)
                  */
                 m_pre_split = false;
             }
         } else {
             READWRITE(fInternal);
             READWRITE(m_pre_split);
         }
     }
 };
 
 /** Address book data */
 class CAddressBookData {
 public:
     std::string name;
     std::string purpose;
 
     CAddressBookData() : purpose("unknown") {}
 
     typedef std::map<std::string, std::string> StringMap;
     StringMap destdata;
 };
 
 struct CRecipient {
     CScript scriptPubKey;
     Amount nAmount;
     bool fSubtractFeeFromAmount;
 };
 
 typedef std::map<std::string, std::string> mapValue_t;
 
 static inline void ReadOrderPos(int64_t &nOrderPos, mapValue_t &mapValue) {
     if (!mapValue.count("n")) {
         // TODO: calculate elsewhere
         nOrderPos = -1;
         return;
     }
 
     nOrderPos = atoi64(mapValue["n"].c_str());
 }
 
 static inline void WriteOrderPos(const int64_t &nOrderPos,
                                  mapValue_t &mapValue) {
     if (nOrderPos == -1) {
         return;
     }
     mapValue["n"] = i64tostr(nOrderPos);
 }
 
 struct COutputEntry {
     CTxDestination destination;
     Amount amount;
     int vout;
 };
 
 /** A transaction with a merkle branch linking it to the block chain. */
 class CMerkleTx {
 private:
     /** Constant used in hashBlock to indicate tx has been abandoned */
     static const BlockHash ABANDON_HASH;
 
 public:
     CTransactionRef tx;
     BlockHash hashBlock;
 
     /**
      * An nIndex == -1 means that hashBlock (in nonzero) refers to the earliest
      * block in the chain we know this or any in-wallet dependency conflicts
      * with. Older clients interpret nIndex == -1 as unconfirmed for backward
      * compatibility.
      */
     int nIndex;
 
     CMerkleTx() {
         SetTx(MakeTransactionRef());
         Init();
     }
 
     explicit CMerkleTx(CTransactionRef arg) {
         SetTx(std::move(arg));
         Init();
     }
 
     void Init() {
         hashBlock = BlockHash();
         nIndex = -1;
     }
 
     void SetTx(CTransactionRef arg) { tx = std::move(arg); }
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         // For compatibility with older versions.
         std::vector<uint256> vMerkleBranch;
         READWRITE(tx);
         READWRITE(hashBlock);
         READWRITE(vMerkleBranch);
         READWRITE(nIndex);
     }
 
-    void SetMerkleBranch(const CBlockIndex *pIndex, int posInBlock);
+    void SetMerkleBranch(const BlockHash &block_hash, int posInBlock);
 
     /**
      * Return depth of transaction in blockchain:
      * <0  : conflicts with a transaction this deep in the blockchain
      *  0  : in memory pool, waiting to be included in a block
      * >=1 : this many blocks deep in the main chain
      */
     int GetDepthInMainChain(interfaces::Chain::Lock &locked_chain) const;
     bool IsInMainChain(interfaces::Chain::Lock &locked_chain) const {
         return GetDepthInMainChain(locked_chain) > 0;
     }
 
     /**
      * @return number of blocks to maturity for this transaction:
      *  0 : is not a coinbase transaction, or is a mature coinbase transaction
      * >0 : is a coinbase transaction which matures in this many blocks
      */
     int GetBlocksToMaturity(interfaces::Chain::Lock &locked_chain) const;
     bool hashUnset() const {
         return (hashBlock.IsNull() || hashBlock == ABANDON_HASH);
     }
     bool isAbandoned() const { return (hashBlock == ABANDON_HASH); }
     void setAbandoned() { hashBlock = ABANDON_HASH; }
 
     TxId GetId() const { return tx->GetId(); }
     bool IsCoinBase() const { return tx->IsCoinBase(); }
     bool IsImmatureCoinBase(interfaces::Chain::Lock &locked_chain) const;
 };
 
 // Get the marginal bytes of spending the specified output
 int CalculateMaximumSignedInputSize(const CTxOut &txout, const CWallet *pwallet,
                                     bool use_max_sig = false);
 
 /**
  * A transaction with a bunch of additional info that only the owner cares
  * about. It includes any unrecorded transactions needed to link it back to the
  * block chain.
  */
 class CWalletTx : public CMerkleTx {
 private:
     const CWallet *pwallet;
 
 public:
     /**
      * Key/value map with information about the transaction.
      *
      * The following keys can be read and written through the map and are
      * serialized in the wallet database:
      *
      *     "comment", "to"   - comment strings provided to sendtoaddress,
      *                         and sendmany wallet RPCs
      *     "replaces_txid"   - txid (as HexStr) of transaction replaced by
      *                         bumpfee on transaction created by bumpfee
      *     "replaced_by_txid" - txid (as HexStr) of transaction created by
      *                         bumpfee on transaction replaced by bumpfee
      *     "from", "message" - obsolete fields that could be set in UI prior to
      *                         2011 (removed in commit 4d9b223)
      *
      * The following keys are serialized in the wallet database, but shouldn't
      * be read or written through the map (they will be temporarily added and
      * removed from the map during serialization):
      *
      *     "fromaccount"     - serialized strFromAccount value
      *     "n"               - serialized nOrderPos value
      *     "timesmart"       - serialized nTimeSmart value
      *     "spent"           - serialized vfSpent value that existed prior to
      *                         2014 (removed in commit 93a18a3)
      */
     mapValue_t mapValue;
     std::vector<std::pair<std::string, std::string>> vOrderForm;
     unsigned int fTimeReceivedIsTxTime;
     //! time received by this node
     unsigned int nTimeReceived;
     /**
      * Stable timestamp that never changes, and reflects the order a transaction
      * was added to the wallet. Timestamp is based on the block time for a
      * transaction added as part of a block, or else the time when the
      * transaction was received if it wasn't part of a block, with the timestamp
      * adjusted in both cases so timestamp order matches the order transactions
      * were added to the wallet. More details can be found in
      * CWallet::ComputeTimeSmart().
      */
     unsigned int nTimeSmart;
     /**
      * From me flag is set to 1 for transactions that were created by the wallet
      * on this bitcoin node, and set to 0 for transactions that were created
      * externally and came in through the network or sendrawtransaction RPC.
      */
     char fFromMe;
     //! position in ordered transaction list
     int64_t nOrderPos;
     std::multimap<int64_t, CWalletTx *>::const_iterator m_it_wtxOrdered;
 
     // memory only
     mutable bool fDebitCached;
     mutable bool fCreditCached;
     mutable bool fImmatureCreditCached;
     mutable bool fAvailableCreditCached;
     mutable bool fWatchDebitCached;
     mutable bool fWatchCreditCached;
     mutable bool fImmatureWatchCreditCached;
     mutable bool fAvailableWatchCreditCached;
     mutable bool fChangeCached;
     mutable bool fInMempool;
     mutable Amount nDebitCached;
     mutable Amount nCreditCached;
     mutable Amount nImmatureCreditCached;
     mutable Amount nAvailableCreditCached;
     mutable Amount nWatchDebitCached;
     mutable Amount nWatchCreditCached;
     mutable Amount nImmatureWatchCreditCached;
     mutable Amount nAvailableWatchCreditCached;
     mutable Amount nChangeCached;
 
     CWalletTx(const CWallet *pwalletIn, CTransactionRef arg)
         : CMerkleTx(std::move(arg)) {
         Init(pwalletIn);
     }
 
     void Init(const CWallet *pwalletIn) {
         pwallet = pwalletIn;
         mapValue.clear();
         vOrderForm.clear();
         fTimeReceivedIsTxTime = false;
         nTimeReceived = 0;
         nTimeSmart = 0;
         fFromMe = false;
         fDebitCached = false;
         fCreditCached = false;
         fImmatureCreditCached = false;
         fAvailableCreditCached = false;
         fWatchDebitCached = false;
         fWatchCreditCached = false;
         fImmatureWatchCreditCached = false;
         fAvailableWatchCreditCached = false;
         fChangeCached = false;
         fInMempool = false;
         nDebitCached = Amount::zero();
         nCreditCached = Amount::zero();
         nImmatureCreditCached = Amount::zero();
         nAvailableCreditCached = Amount::zero();
         nWatchDebitCached = Amount::zero();
         nWatchCreditCached = Amount::zero();
         nAvailableWatchCreditCached = Amount::zero();
         nImmatureWatchCreditCached = Amount::zero();
         nChangeCached = Amount::zero();
         nOrderPos = -1;
     }
 
     template <typename Stream> void Serialize(Stream &s) const {
         char fSpent = false;
         mapValue_t mapValueCopy = mapValue;
 
         mapValueCopy["fromaccount"] = "";
         WriteOrderPos(nOrderPos, mapValueCopy);
         if (nTimeSmart) {
             mapValueCopy["timesmart"] = strprintf("%u", nTimeSmart);
         }
 
         s << static_cast<const CMerkleTx &>(*this);
         //! Used to be vtxPrev
         std::vector<CMerkleTx> vUnused;
         s << vUnused << mapValueCopy << vOrderForm << fTimeReceivedIsTxTime
           << nTimeReceived << fFromMe << fSpent;
     }
 
     template <typename Stream> void Unserialize(Stream &s) {
         Init(nullptr);
         char fSpent;
 
         s >> static_cast<CMerkleTx &>(*this);
         //! Used to be vtxPrev
         std::vector<CMerkleTx> vUnused;
         s >> vUnused >> mapValue >> vOrderForm >> fTimeReceivedIsTxTime >>
             nTimeReceived >> fFromMe >> fSpent;
 
         ReadOrderPos(nOrderPos, mapValue);
         nTimeSmart = mapValue.count("timesmart")
                          ? (unsigned int)atoi64(mapValue["timesmart"])
                          : 0;
 
         mapValue.erase("fromaccount");
         mapValue.erase("spent");
         mapValue.erase("n");
         mapValue.erase("timesmart");
     }
 
     //! make sure balances are recalculated
     void MarkDirty() {
         fCreditCached = false;
         fAvailableCreditCached = false;
         fImmatureCreditCached = false;
         fWatchDebitCached = false;
         fWatchCreditCached = false;
         fAvailableWatchCreditCached = false;
         fImmatureWatchCreditCached = false;
         fDebitCached = false;
         fChangeCached = false;
     }
 
     void BindWallet(CWallet *pwalletIn) {
         pwallet = pwalletIn;
         MarkDirty();
     }
 
     //! filter decides which addresses will count towards the debit
     Amount GetDebit(const isminefilter &filter) const;
     Amount GetCredit(interfaces::Chain::Lock &locked_chain,
                      const isminefilter &filter) const;
     Amount GetImmatureCredit(interfaces::Chain::Lock &locked_chain,
                              bool fUseCache = true) const;
     // TODO: Remove "NO_THREAD_SAFETY_ANALYSIS" and replace it with the correct
     // annotation "EXCLUSIVE_LOCKS_REQUIRED(cs_main, pwallet->cs_wallet)". The
     // annotation "NO_THREAD_SAFETY_ANALYSIS" was temporarily added to avoid
     // having to resolve the issue of member access into incomplete type
     // CWallet.
     Amount GetAvailableCredit(interfaces::Chain::Lock &locked_chain,
                               bool fUseCache = true,
                               const isminefilter &filter = ISMINE_SPENDABLE)
         const NO_THREAD_SAFETY_ANALYSIS;
     Amount GetImmatureWatchOnlyCredit(interfaces::Chain::Lock &locked_chain,
                                       const bool fUseCache = true) const;
     Amount GetChange() const;
 
     // Get the marginal bytes if spending the specified output from this
     // transaction
     int GetSpendSize(unsigned int out, bool use_max_sig = false) const {
         return CalculateMaximumSignedInputSize(tx->vout[out], pwallet,
                                                use_max_sig);
     }
 
     void GetAmounts(std::list<COutputEntry> &listReceived,
                     std::list<COutputEntry> &listSent, Amount &nFee,
                     const isminefilter &filter) const;
 
     bool IsFromMe(const isminefilter &filter) const {
         return GetDebit(filter) > Amount::zero();
     }
 
     // True if only scriptSigs are different
     bool IsEquivalentTo(const CWalletTx &tx) const;
 
     bool InMempool() const;
     bool IsTrusted(interfaces::Chain::Lock &locked_chain) const;
 
     int64_t GetTxTime() const;
 
     // RelayWalletTransaction may only be called if fBroadcastTransactions!
     bool RelayWalletTransaction(interfaces::Chain::Lock &locked_chain,
                                 CConnman *connman);
 
     /**
      * Pass this transaction to the mempool. Fails if absolute fee exceeds
      * absurd fee.
      */
     bool AcceptToMemoryPool(interfaces::Chain::Lock &locked_chain,
                             const Amount nAbsurdFee, CValidationState &state);
 
     // TODO: Remove "NO_THREAD_SAFETY_ANALYSIS" and replace it with the correct
     // annotation "EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)". The annotation
     // "NO_THREAD_SAFETY_ANALYSIS" was temporarily added to avoid having to
     // resolve the issue of member access into incomplete type CWallet. Note
     // that we still have the runtime check "AssertLockHeld(pwallet->cs_wallet)"
     // in place.
     std::set<TxId> GetConflicts() const NO_THREAD_SAFETY_ANALYSIS;
 };
 
 class COutput {
 public:
     const CWalletTx *tx;
     int i;
     int nDepth;
 
     /**
      * Pre-computed estimated size of this output as a fully-signed input in a
      * transaction. Can be -1 if it could not be calculated.
      */
     int nInputBytes;
 
     /** Whether we have the private keys to spend this output */
     bool fSpendable;
 
     /** Whether we know how to spend this output, ignoring the lack of keys */
     bool fSolvable;
 
     /**
      * Whether to use the maximum sized, 72 byte signature when calculating the
      * size of the input spend. This should only be set when watch-only outputs
      * are allowed.
      */
     bool use_max_sig;
 
     /**
      * Whether this output is considered safe to spend. Unconfirmed transactions
      * from outside keys are considered unsafe and will not be used to fund new
      * spending transactions.
      */
     bool fSafe;
 
     COutput(const CWalletTx *txIn, int iIn, int nDepthIn, bool fSpendableIn,
             bool fSolvableIn, bool fSafeIn, bool use_max_sig_in = false) {
         tx = txIn;
         i = iIn;
         nDepth = nDepthIn;
         fSpendable = fSpendableIn;
         fSolvable = fSolvableIn;
         fSafe = fSafeIn;
         nInputBytes = -1;
         use_max_sig = use_max_sig_in;
         // If known and signable by the given wallet, compute nInputBytes
         // Failure will keep this value -1
         if (fSpendable && tx) {
             nInputBytes = tx->GetSpendSize(i, use_max_sig);
         }
     }
 
     std::string ToString() const;
 
     inline CInputCoin GetInputCoin() const {
         return CInputCoin(tx->tx, i, nInputBytes);
     }
 };
 
 /** Private key that includes an expiration date in case it never gets used. */
 class CWalletKey {
 public:
     CPrivKey vchPrivKey;
     int64_t nTimeCreated;
     int64_t nTimeExpires;
     std::string strComment;
     //! todo: add something to note what created it (user, getnewaddress,
     //! change) maybe should have a map<string, string> property map
 
     explicit CWalletKey(int64_t nExpires = 0);
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         int nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) {
             READWRITE(nVersion);
         }
         READWRITE(vchPrivKey);
         READWRITE(nTimeCreated);
         READWRITE(nTimeExpires);
         READWRITE(LIMITED_STRING(strComment, 65536));
     }
 };
 
 struct CoinSelectionParams {
     bool use_bnb = true;
     size_t change_output_size = 0;
     size_t change_spend_size = 0;
     CFeeRate effective_fee = CFeeRate(Amount::zero());
     size_t tx_noinputs_size = 0;
 
     CoinSelectionParams(bool use_bnb_, size_t change_output_size_,
                         size_t change_spend_size_, CFeeRate effective_fee_,
                         size_t tx_noinputs_size_)
         : use_bnb(use_bnb_), change_output_size(change_output_size_),
           change_spend_size(change_spend_size_), effective_fee(effective_fee_),
           tx_noinputs_size(tx_noinputs_size_) {}
     CoinSelectionParams() {}
 };
 
 // forward declarations for ScanForWalletTransactions/RescanFromTime
 class WalletRescanReserver;
 
 /**
  * A CWallet is an extension of a keystore, which also maintains a set of
  * transactions and balances, and provides the ability to create new
  * transactions.
  */
 class CWallet final : public CCryptoKeyStore, public CValidationInterface {
 private:
     static std::atomic<bool> fFlushScheduled;
     std::atomic<bool> fAbortRescan{false};
     // controlled by WalletRescanReserver
     std::atomic<bool> fScanningWallet{false};
     std::mutex mutexScanning;
     friend class WalletRescanReserver;
 
     WalletBatch *encrypted_batch GUARDED_BY(cs_wallet) = nullptr;
 
     //! the current wallet version: clients below this version are not able to
     //! load the wallet
     int nWalletVersion = FEATURE_BASE;
 
     //! the maximum wallet format version: memory-only variable that specifies
     //! to what version this wallet may be upgraded
     int nWalletMaxVersion GUARDED_BY(cs_wallet) = FEATURE_BASE;
 
     int64_t nNextResend = 0;
     int64_t nLastResend = 0;
     bool fBroadcastTransactions = false;
 
     /**
      * Used to keep track of spent outpoints, and detect and report conflicts
      * (double-spends or mutated transactions where the mutant gets mined).
      */
     typedef std::multimap<COutPoint, TxId> TxSpends;
     TxSpends mapTxSpends GUARDED_BY(cs_wallet);
     void AddToSpends(const COutPoint &outpoint, const TxId &wtxid)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void AddToSpends(const TxId &wtxid) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Add a transaction to the wallet, or update it. pIndex and posInBlock
      * should be set when the transaction was known to be included in a
      * block. When *pIndex == nullptr, then wallet state is not updated in
      * AddToWallet, but notifications happen and cached balances are marked
      * dirty.
      *
      * If fUpdate is true, existing transactions will be updated.
      * TODO: One exception to this is that the abandoned state is cleared under
      * the assumption that any further notification of a transaction that was
      * considered abandoned is an indication that it is not safe to be
      * considered abandoned. Abandoned state should probably be more carefully
      * tracked via different posInBlock signals or by checking mempool presence
      * when necessary.
      */
     bool AddToWalletIfInvolvingMe(const CTransactionRef &tx,
-                                  const CBlockIndex *pIndex, int posInBlock,
+                                  const BlockHash &block_hash, int posInBlock,
                                   bool fUpdate)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Mark a transaction (and its in-wallet descendants) as conflicting with a
      * particular block.
      */
     void MarkConflicted(const BlockHash &hashBlock, const TxId &txid);
 
     /**
      * Mark a transaction's inputs dirty, thus forcing the outputs to be
      * recomputed
      */
     void MarkInputsDirty(const CTransactionRef &tx)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     void SyncMetaData(std::pair<TxSpends::iterator, TxSpends::iterator>)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Used by
      * TransactionAddedToMemorypool/BlockConnected/Disconnected/ScanForWalletTransactions.
-     * Should be called with pindexBlock and posInBlock if this is for a
+     * Should be called with non-zero block_hash and posInBlock if this is for a
      * transaction that is included in a block.
      */
-    void SyncTransaction(const CTransactionRef &tx,
-                         const CBlockIndex *pindex = nullptr,
+    void SyncTransaction(const CTransactionRef &tx, const BlockHash &block_hash,
                          int posInBlock = 0, bool update_tx = true)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /* the HD chain data model (external chain counters) */
     CHDChain hdChain;
 
     /* HD derive new child key (on internal or external chain) */
     void DeriveNewChildKey(WalletBatch &batch, CKeyMetadata &metadata,
                            CKey &secret, bool internal = false)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     std::set<int64_t> setInternalKeyPool;
     std::set<int64_t> setExternalKeyPool GUARDED_BY(cs_wallet);
     std::set<int64_t> set_pre_split_keypool;
     int64_t m_max_keypool_index GUARDED_BY(cs_wallet) = 0;
     std::map<CKeyID, int64_t> m_pool_key_to_index;
     std::atomic<uint64_t> m_wallet_flags{0};
 
     int64_t nTimeFirstKey GUARDED_BY(cs_wallet) = 0;
 
     /**
      * Private version of AddWatchOnly method which does not accept a timestamp,
      * and which will reset the wallet's nTimeFirstKey value to 1 if the watch
      * key did not previously have a timestamp associated with it. Because this
      * is an inherited virtual method, it is accessible despite being marked
      * private, but it is marked private anyway to encourage use of the other
      * AddWatchOnly which accepts a timestamp and sets nTimeFirstKey more
      * intelligently for more efficient rescans.
      */
     bool AddWatchOnly(const CScript &dest) override
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /** Interface for accessing chain state. */
     interfaces::Chain &m_chain;
 
     /**
      * Wallet location which includes wallet name (see WalletLocation).
      */
     WalletLocation m_location;
 
     /** Internal database handle. */
     std::unique_ptr<WalletDatabase> database;
 
     /**
      * The following is used to keep track of how far behind the wallet is
      * from the chain sync, and to allow clients to block on us being caught up.
      *
      * Note that this is *not* how far we've processed, we may need some rescan
      * to have seen all transactions in the chain, but is only used to track
      * live BlockConnected callbacks.
-     *
-     * Protected by cs_main (see BlockUntilSyncedToCurrentChain)
      */
-    const CBlockIndex *m_last_block_processed = nullptr;
+    BlockHash m_last_block_processed;
 
 public:
     const CChainParams &chainParams;
     /*
      * Main wallet lock.
      * This lock protects all the fields added by CWallet.
      */
     mutable CCriticalSection cs_wallet;
 
     /**
      * Get database handle used by this wallet. Ideally this function would not
      * be necessary.
      */
     WalletDatabase &GetDBHandle() { return *database; }
 
     /**
      * Select a set of coins such that nValueRet >= nTargetValue and at least
      * all coins from coinControl are selected; Never select unconfirmed coins
      * if they are not ours.
      */
     bool SelectCoins(const std::vector<COutput> &vAvailableCoins,
                      const Amount nTargetValue,
                      std::set<CInputCoin> &setCoinsRet, Amount &nValueRet,
                      const CCoinControl &coin_control,
                      CoinSelectionParams &coin_selection_params,
                      bool &bnb_used) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     const WalletLocation &GetLocation() const { return m_location; }
 
     /**
      * Get a name for this wallet for logging/debugging purposes.
      */
     const std::string &GetName() const { return m_location.GetName(); }
 
     void LoadKeyPool(int64_t nIndex, const CKeyPool &keypool)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void MarkPreSplitKeys() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     // Map from Key ID to key metadata.
     std::map<CKeyID, CKeyMetadata> mapKeyMetadata GUARDED_BY(cs_wallet);
 
     // Map from Script ID to key metadata (for watch-only keys).
     std::map<CScriptID, CKeyMetadata> m_script_metadata GUARDED_BY(cs_wallet);
 
     typedef std::map<unsigned int, CMasterKey> MasterKeyMap;
     MasterKeyMap mapMasterKeys;
     unsigned int nMasterKeyMaxID = 0;
 
     /** Construct wallet with specified name and database implementation. */
     CWallet(const CChainParams &chainParamsIn, interfaces::Chain &chain,
             const WalletLocation &location,
             std::unique_ptr<WalletDatabase> databaseIn)
         : m_chain(chain), m_location(location), database(std::move(databaseIn)),
           chainParams(chainParamsIn) {}
 
     ~CWallet() {
         // Should not have slots connected at this point.
         assert(NotifyUnload.empty());
         delete encrypted_batch;
         encrypted_batch = nullptr;
     }
 
     std::map<TxId, CWalletTx> mapWallet GUARDED_BY(cs_wallet);
 
     typedef std::multimap<int64_t, CWalletTx *> TxItems;
     TxItems wtxOrdered;
 
     int64_t nOrderPosNext GUARDED_BY(cs_wallet) = 0;
     uint64_t nAccountingEntryNumber = 0;
 
     std::map<CTxDestination, CAddressBookData> mapAddressBook;
 
     std::set<COutPoint> setLockedCoins GUARDED_BY(cs_wallet);
 
     /** Interface for accessing chain state. */
     interfaces::Chain &chain() const { return m_chain; }
 
     const CWalletTx *GetWalletTx(const TxId &txid) const;
 
     //! check whether we are allowed to upgrade (or already support) to the
     //! named feature
     bool CanSupportFeature(enum WalletFeature wf) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet) {
         AssertLockHeld(cs_wallet);
         return nWalletMaxVersion >= wf;
     }
 
     /**
      * populate vCoins with vector of available COutputs.
      */
     void AvailableCoins(interfaces::Chain::Lock &locked_chain,
                         std::vector<COutput> &vCoins, bool fOnlySafe = true,
                         const CCoinControl *coinControl = nullptr,
                         const Amount nMinimumAmount = SATOSHI,
                         const Amount nMaximumAmount = MAX_MONEY,
                         const Amount nMinimumSumAmount = MAX_MONEY,
                         const uint64_t nMaximumCount = 0,
                         const int nMinDepth = 0,
                         const int nMaxDepth = 9999999) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Return list of available coins and locked coins grouped by non-change
      * output address.
      */
     std::map<CTxDestination, std::vector<COutput>>
     ListCoins(interfaces::Chain::Lock &locked_chain) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Find non-change parent output.
      */
     const CTxOut &FindNonChangeParentOutput(const CTransaction &tx,
                                             int output) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Shuffle and select coins until nTargetValue is reached while avoiding
      * small change; This method is stochastic for some inputs and upon
      * completion the coin set and corresponding actual target value is
      * assembled.
      */
     bool SelectCoinsMinConf(const Amount nTargetValue,
                             const CoinEligibilityFilter &eligibility_filter,
                             std::vector<OutputGroup> groups,
                             std::set<CInputCoin> &setCoinsRet,
                             Amount &nValueRet,
                             const CoinSelectionParams &coin_selection_params,
                             bool &bnb_used) const;
 
     bool IsSpent(interfaces::Chain::Lock &locked_chain,
                  const COutPoint &outpoint) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     std::vector<OutputGroup> GroupOutputs(const std::vector<COutput> &outputs,
                                           bool single_coin) const;
 
     bool IsLockedCoin(const COutPoint &outpoint) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void LockCoin(const COutPoint &output) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void UnlockCoin(const COutPoint &output)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void UnlockAllCoins() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void ListLockedCoins(std::vector<COutPoint> &vOutpts) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /*
      * Rescan abort properties
      */
     void AbortRescan() { fAbortRescan = true; }
     bool IsAbortingRescan() { return fAbortRescan; }
     bool IsScanning() { return fScanningWallet; }
 
     /**
      * keystore implementation
      * Generate a new key
      */
     CPubKey GenerateNewKey(WalletBatch &batch, bool internal = false)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Adds a key to the store, and saves it to disk.
     bool AddKeyPubKey(const CKey &key, const CPubKey &pubkey) override
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool AddKeyPubKeyWithDB(WalletBatch &batch, const CKey &key,
                             const CPubKey &pubkey)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Adds a key to the store, without saving it to disk (used by LoadWallet)
     bool LoadKey(const CKey &key, const CPubKey &pubkey) {
         return CCryptoKeyStore::AddKeyPubKey(key, pubkey);
     }
 
     //! Load metadata (used by LoadWallet)
     void LoadKeyMetadata(const CKeyID &keyID, const CKeyMetadata &metadata)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void LoadScriptMetadata(const CScriptID &script_id,
                             const CKeyMetadata &metadata)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     bool LoadMinVersion(int nVersion) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet) {
         AssertLockHeld(cs_wallet);
         nWalletVersion = nVersion;
         nWalletMaxVersion = std::max(nWalletMaxVersion, nVersion);
         return true;
     }
     void UpdateTimeFirstKey(int64_t nCreateTime)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     //! Adds an encrypted key to the store, and saves it to disk.
     bool AddCryptedKey(const CPubKey &vchPubKey,
                        const std::vector<uint8_t> &vchCryptedSecret) override;
     //! Adds an encrypted key to the store, without saving it to disk (used by
     //! LoadWallet)
     bool LoadCryptedKey(const CPubKey &vchPubKey,
                         const std::vector<uint8_t> &vchCryptedSecret);
     bool AddCScript(const CScript &redeemScript) override;
     bool LoadCScript(const CScript &redeemScript);
 
     //! Adds a destination data tuple to the store, and saves it to disk
     bool AddDestData(const CTxDestination &dest, const std::string &key,
                      const std::string &value);
     //! Erases a destination data tuple in the store and on disk
     bool EraseDestData(const CTxDestination &dest, const std::string &key);
     //! Adds a destination data tuple to the store, without saving it to disk
     void LoadDestData(const CTxDestination &dest, const std::string &key,
                       const std::string &value);
     //! Look up a destination data tuple in the store, return true if found
     //! false otherwise
     bool GetDestData(const CTxDestination &dest, const std::string &key,
                      std::string *value) const;
     //! Get all destination values matching a prefix.
     std::vector<std::string> GetDestValues(const std::string &prefix) const;
 
     //! Adds a watch-only address to the store, and saves it to disk.
     bool AddWatchOnly(const CScript &dest, int64_t nCreateTime)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool RemoveWatchOnly(const CScript &dest) override
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Adds a watch-only address to the store, without saving it to disk (used
     //! by LoadWallet)
     bool LoadWatchOnly(const CScript &dest);
 
     //! Holds a timestamp at which point the wallet is scheduled (externally) to
     //! be relocked. Caller must arrange for actual relocking to occur via
     //! Lock().
     int64_t nRelockTime = 0;
 
     bool Unlock(const SecureString &strWalletPassphrase);
     bool ChangeWalletPassphrase(const SecureString &strOldWalletPassphrase,
                                 const SecureString &strNewWalletPassphrase);
     bool EncryptWallet(const SecureString &strWalletPassphrase);
 
     void GetKeyBirthTimes(interfaces::Chain::Lock &locked_chain,
                           std::map<CTxDestination, int64_t> &mapKeyBirth) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     unsigned int ComputeTimeSmart(const CWalletTx &wtx) const;
 
     /**
      * Increment the next transaction order id
      * @return next transaction order id
      */
     int64_t IncOrderPosNext(WalletBatch *batch = nullptr)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     DBErrors ReorderTransactions();
 
     void MarkDirty();
     bool AddToWallet(const CWalletTx &wtxIn, bool fFlushOnClose = true);
     void LoadToWallet(const CWalletTx &wtxIn)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void TransactionAddedToMempool(const CTransactionRef &tx) override;
     void
     BlockConnected(const std::shared_ptr<const CBlock> &pblock,
                    const CBlockIndex *pindex,
                    const std::vector<CTransactionRef> &vtxConflicted) override;
     void
     BlockDisconnected(const std::shared_ptr<const CBlock> &pblock) override;
     int64_t RescanFromTime(int64_t startTime,
                            const WalletRescanReserver &reserver, bool update);
 
-    enum class ScanResult { SUCCESS, FAILURE, USER_ABORT };
-    ScanResult ScanForWalletTransactions(const CBlockIndex *const pindexStart,
-                                         const CBlockIndex *const pindexStop,
+    struct ScanResult {
+        enum { SUCCESS, FAILURE, USER_ABORT } status = SUCCESS;
+
+        //! Hash and height of most recent block that was successfully scanned.
+        //! Unset if no blocks were scanned due to read errors or the chain
+        //! being empty.
+        BlockHash stop_block;
+        Optional<int> stop_height;
+
+        //! Hash of the most recent block that could not be scanned due to
+        //! read errors or pruning. Will be set if status is FAILURE, unset if
+        //! status is SUCCESS, and may or may not be set if status is
+        //! USER_ABORT.
+        BlockHash failed_block;
+    };
+    ScanResult ScanForWalletTransactions(const BlockHash &first_block,
+                                         const BlockHash &last_block,
                                          const WalletRescanReserver &reserver,
-                                         const CBlockIndex *&failed_block,
-                                         const CBlockIndex *&stop_block,
-                                         bool fUpdate = false);
+                                         bool fUpdate);
     void TransactionRemovedFromMempool(const CTransactionRef &ptx) override;
     void ReacceptWalletTransactions();
     void ResendWalletTransactions(int64_t nBestBlockTime,
                                   CConnman *connman) override
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     // ResendWalletTransactionsBefore may only be called if
     // fBroadcastTransactions!
     std::vector<uint256>
     ResendWalletTransactionsBefore(interfaces::Chain::Lock &locked_chain,
                                    int64_t nTime, CConnman *connman);
     Amount GetBalance(const isminefilter &filter = ISMINE_SPENDABLE,
                       const int min_depth = 0) const;
     Amount GetUnconfirmedBalance() const;
     Amount GetImmatureBalance() const;
     Amount GetUnconfirmedWatchOnlyBalance() const;
     Amount GetImmatureWatchOnlyBalance() const;
     Amount GetLegacyBalance(const isminefilter &filter, int minDepth) const;
     Amount GetAvailableBalance(const CCoinControl *coinControl = nullptr) const;
 
     OutputType TransactionChangeType(OutputType change_type,
                                      const std::vector<CRecipient> &vecSend);
 
     /**
      * Insert additional inputs into the transaction by calling
      * CreateTransaction();
      */
     bool FundTransaction(CMutableTransaction &tx, Amount &nFeeRet,
                          int &nChangePosInOut, std::string &strFailReason,
                          bool lockUnspents,
                          const std::set<int> &setSubtractFeeFromOutputs,
                          CCoinControl coinControl);
     bool SignTransaction(CMutableTransaction &tx)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Create a new transaction paying the recipients with a set of coins
      * selected by SelectCoins(); Also create the change output, when needed
      * @note passing nChangePosInOut as -1 will result in setting a random
      * position
      */
     bool CreateTransaction(interfaces::Chain::Lock &locked_chain,
                            const std::vector<CRecipient> &vecSend,
                            CTransactionRef &tx, CReserveKey &reservekey,
                            Amount &nFeeRet, int &nChangePosInOut,
                            std::string &strFailReason,
                            const CCoinControl &coin_control, bool sign = true);
     bool CommitTransaction(
         CTransactionRef tx, mapValue_t mapValue,
         std::vector<std::pair<std::string, std::string>> orderForm,
         CReserveKey &reservekey, CConnman *connman, CValidationState &state);
 
     bool DummySignTx(CMutableTransaction &txNew, const std::set<CTxOut> &txouts,
                      bool use_max_sig = false) const {
         std::vector<CTxOut> v_txouts(txouts.size());
         std::copy(txouts.begin(), txouts.end(), v_txouts.begin());
         return DummySignTx(txNew, v_txouts, use_max_sig);
     }
     bool DummySignTx(CMutableTransaction &txNew,
                      const std::vector<CTxOut> &txouts,
                      bool use_max_sig = false) const;
     bool DummySignInput(CTxIn &tx_in, const CTxOut &txout,
                         bool use_max_sig = false) const;
 
     CFeeRate m_pay_tx_fee{DEFAULT_PAY_TX_FEE};
     bool m_spend_zero_conf_change{DEFAULT_SPEND_ZEROCONF_CHANGE};
     // will be defined via chainparams
     bool m_allow_fallback_fee{true};
     // Override with -mintxfee
     CFeeRate m_min_fee{DEFAULT_TRANSACTION_MINFEE_PER_KB};
     /**
      * If fee estimation does not have enough data to provide estimates, use
      * this fee instead. Has no effect if not using fee estimation Override with
      * -fallbackfee
      */
     CFeeRate m_fallback_fee{DEFAULT_FALLBACK_FEE};
     OutputType m_default_address_type{DEFAULT_ADDRESS_TYPE};
     OutputType m_default_change_type{DEFAULT_CHANGE_TYPE};
 
     bool NewKeyPool();
     size_t KeypoolCountExternalKeys() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool TopUpKeyPool(unsigned int kpSize = 0);
 
     /**
      * Reserves a key from the keypool and sets nIndex to its index
      *
      * @param[out] nIndex the index of the key in keypool
      * @param[out] keypool the keypool the key was drawn from, which could be
      * the the pre-split pool if present, or the internal or external pool
      * @param fRequestedInternal true if the caller would like the key drawn
      *     from the internal keypool, false if external is preferred
      *
      * @return true if succeeded, false if failed due to empty keypool
      * @throws std::runtime_error if keypool read failed, key was invalid,
      *     was not found in the wallet, or was misclassified in the internal
      *     or external keypool
      */
     bool ReserveKeyFromKeyPool(int64_t &nIndex, CKeyPool &keypool,
                                bool fRequestedInternal);
     void KeepKey(int64_t nIndex);
     void ReturnKey(int64_t nIndex, bool fInternal, const CPubKey &pubkey);
     bool GetKeyFromPool(CPubKey &key, bool internal = false);
     int64_t GetOldestKeyPoolTime();
     /**
      * Marks all keys in the keypool up to and including reserve_key as used.
      */
     void MarkReserveKeysAsUsed(int64_t keypool_id)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     const std::map<CKeyID, int64_t> &GetAllReserveKeys() const {
         return m_pool_key_to_index;
     }
 
     std::set<std::set<CTxDestination>> GetAddressGroupings()
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     std::map<CTxDestination, Amount>
     GetAddressBalances(interfaces::Chain::Lock &locked_chain);
 
     std::set<CTxDestination> GetLabelAddresses(const std::string &label) const;
 
     isminetype IsMine(const CTxIn &txin) const;
     /**
      * Returns amount of debit if the input matches the filter, otherwise
      * returns 0
      */
     Amount GetDebit(const CTxIn &txin, const isminefilter &filter) const;
     isminetype IsMine(const CTxOut &txout) const;
     Amount GetCredit(const CTxOut &txout, const isminefilter &filter) const;
     bool IsChange(const CTxOut &txout) const;
     bool IsChange(const CScript &script) const;
     Amount GetChange(const CTxOut &txout) const;
     bool IsMine(const CTransaction &tx) const;
     /** should probably be renamed to IsRelevantToMe */
     bool IsFromMe(const CTransaction &tx) const;
     Amount GetDebit(const CTransaction &tx, const isminefilter &filter) const;
     /** Returns whether all of the inputs match the filter */
     bool IsAllFromMe(const CTransaction &tx, const isminefilter &filter) const;
     Amount GetCredit(const CTransaction &tx, const isminefilter &filter) const;
     Amount GetChange(const CTransaction &tx) const;
     void ChainStateFlushed(const CBlockLocator &loc) override;
 
     DBErrors LoadWallet(bool &fFirstRunRet);
     DBErrors ZapWalletTx(std::vector<CWalletTx> &vWtx);
     DBErrors ZapSelectTx(std::vector<TxId> &txIdsIn,
                          std::vector<TxId> &txIdsOut)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     bool SetAddressBook(const CTxDestination &address,
                         const std::string &strName, const std::string &purpose);
 
     bool DelAddressBook(const CTxDestination &address);
 
     const std::string &GetLabelName(const CScript &scriptPubKey) const;
 
     void GetScriptForMining(std::shared_ptr<CReserveScript> &script);
 
     unsigned int GetKeyPoolSize() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet) {
         // set{Ex,In}ternalKeyPool
         AssertLockHeld(cs_wallet);
         return setInternalKeyPool.size() + setExternalKeyPool.size();
     }
 
     //! signify that a particular wallet feature is now used. this may change
     //! nWalletVersion and nWalletMaxVersion if those are lower
     void SetMinVersion(enum WalletFeature, WalletBatch *batch_in = nullptr,
                        bool fExplicit = false);
 
     //! change which version we're allowed to upgrade to (note that this does
     //! not immediately imply upgrading to that format)
     bool SetMaxVersion(int nVersion);
 
     //! get the current wallet format (the oldest client version guaranteed to
     //! understand this wallet)
     int GetVersion() {
         LOCK(cs_wallet);
         return nWalletVersion;
     }
 
     //! Get wallet transactions that conflict with given transaction (spend same
     //! outputs)
     std::set<TxId> GetConflicts(const TxId &txid) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     //! Check if a given transaction has any of its outputs spent by another
     //! transaction in the wallet
     bool HasWalletSpend(const TxId &txid) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     //! Flush wallet (bitdb flush)
     void Flush(bool shutdown = false);
 
     /** Wallet is about to be unloaded */
     boost::signals2::signal<void()> NotifyUnload;
 
     /**
      * Address book entry changed.
      * @note called with lock cs_wallet held.
      */
     boost::signals2::signal<void(CWallet *wallet, const CTxDestination &address,
                                  const std::string &label, bool isMine,
                                  const std::string &purpose, ChangeType status)>
         NotifyAddressBookChanged;
 
     /**
      * Wallet transaction added, removed or updated.
      * @note called with lock cs_wallet held.
      */
     boost::signals2::signal<void(CWallet *wallet, const TxId &txid,
                                  ChangeType status)>
         NotifyTransactionChanged;
 
     /** Show progress e.g. for rescan */
     boost::signals2::signal<void(const std::string &title, int nProgress)>
         ShowProgress;
 
     /** Watch-only address added */
     boost::signals2::signal<void(bool fHaveWatchOnly)> NotifyWatchonlyChanged;
 
     /** Keypool has new keys */
     boost::signals2::signal<void()> NotifyCanGetAddressesChanged;
 
     /** Inquire whether this wallet broadcasts transactions. */
     bool GetBroadcastTransactions() const { return fBroadcastTransactions; }
     /** Set whether this wallet broadcasts transactions. */
     void SetBroadcastTransactions(bool broadcast) {
         fBroadcastTransactions = broadcast;
     }
 
     /** Return whether transaction can be abandoned */
     bool TransactionCanBeAbandoned(const TxId &txid) const;
 
     /**
      * Mark a transaction (and it in-wallet descendants) as abandoned so its
      * inputs may be respent.
      */
     bool AbandonTransaction(interfaces::Chain::Lock &locked_chain,
                             const TxId &txid);
 
     //! Verify wallet naming and perform salvage on the wallet if required
     static bool Verify(const CChainParams &chainParams,
                        interfaces::Chain &chain, const WalletLocation &location,
                        bool salvage_wallet, std::string &error_string,
                        std::string &warning_string);
 
     /**
      * Initializes the wallet, returns a new CWallet instance or a null pointer
      * in case of an error.
      */
     static std::shared_ptr<CWallet> CreateWalletFromFile(
         const CChainParams &chainParams, interfaces::Chain &chain,
         const WalletLocation &location, uint64_t wallet_creation_flags = 0);
 
     /**
      * Wallet post-init setup
      * Gives the wallet a chance to register repetitive tasks and complete
      * post-init tasks
      */
     void postInitProcess();
 
     bool BackupWallet(const std::string &strDest);
 
     /* Set the HD chain model (chain child index counters) */
     void SetHDChain(const CHDChain &chain, bool memonly);
     const CHDChain &GetHDChain() const { return hdChain; }
 
     /* Returns true if HD is enabled */
     bool IsHDEnabled() const;
 
     /* Returns true if the wallet can generate new keys */
     bool CanGenerateKeys();
 
     /**
      * Returns true if the wallet can give out new addresses. This means it has
      * keys in the keypool or can generate new keys.
      */
     bool CanGetAddresses(bool internal = false);
 
     /* Generates a new HD seed (will not be activated) */
     CPubKey GenerateNewSeed();
 
     /**
      * Derives a new HD seed (will not be activated)
      */
     CPubKey DeriveNewSeed(const CKey &key);
 
     /**
      * Set the current HD seed (will reset the chain child index counters)
      * Sets the seed's version based on the current wallet version (so the
      * caller must ensure the current wallet version is correct before calling
      * this function).
      */
     void SetHDSeed(const CPubKey &key);
 
     /**
      * Blocks until the wallet state is up-to-date to /at least/ the current
      * chain at the time this function is entered.
      * Obviously holding cs_main/cs_wallet when going into this call may cause
      * deadlock
      */
     void BlockUntilSyncedToCurrentChain() LOCKS_EXCLUDED(cs_main, cs_wallet);
 
     /**
      * Explicitly make the wallet learn the related scripts for outputs to the
      * given key. This is purely to make the wallet file compatible with older
      * software, as CBasicKeyStore automatically does this implicitly for all
      * keys now.
      */
     void LearnRelatedScripts(const CPubKey &key, OutputType);
 
     /**
      * Same as LearnRelatedScripts, but when the OutputType is not known (and
      * could be anything).
      */
     void LearnAllRelatedScripts(const CPubKey &key);
 
     /**
      * Set a single wallet flag.
      */
     void SetWalletFlag(uint64_t flags);
 
     /**
      * Unsets a single wallet flag.
      */
     void UnsetWalletFlag(uint64_t flag);
 
     /**
      * Check if a certain wallet flag is set.
      */
     bool IsWalletFlagSet(uint64_t flag);
 
     /**
      * Overwrite all flags by the given uint64_t.
      * Returns false if unknown, non-tolerable flags are present.
      */
     bool SetWalletFlags(uint64_t overwriteFlags, bool memOnly);
 
     /**
      * Returns a bracketed wallet name for displaying in logs, will return
      * [default wallet] if the wallet has no name.
      */
     const std::string GetDisplayName() const {
         std::string wallet_name =
             GetName().length() == 0 ? "default wallet" : GetName();
         return strprintf("[%s]", wallet_name);
     };
 
     /**
      * Prepends the wallet name in logging output to ease debugging in
      * multi-wallet use cases.
      */
     template <typename... Params>
     void WalletLogPrintf(std::string fmt, Params... parameters) const {
         LogPrintf(("%s " + fmt).c_str(), GetDisplayName(), parameters...);
     };
 
     template <typename... Params>
     void WalletLogPrintfToBeContinued(std::string fmt,
                                       Params... parameters) const {
         LogPrintfToBeContinued(("%s " + fmt).c_str(), GetDisplayName(),
                                parameters...);
     };
 
     /**
      * Implement lookup of key origin information through wallet key metadata.
      */
     bool GetKeyOrigin(const CKeyID &keyid, KeyOriginInfo &info) const override;
 };
 
 /** A key allocated from the key pool. */
 class CReserveKey final : public CReserveScript {
 protected:
     CWallet *pwallet;
     int64_t nIndex{-1};
     CPubKey vchPubKey;
     bool fInternal{false};
 
 public:
     explicit CReserveKey(CWallet *pwalletIn) { pwallet = pwalletIn; }
 
     CReserveKey(const CReserveKey &) = delete;
     CReserveKey &operator=(const CReserveKey &) = delete;
 
     ~CReserveKey() { ReturnKey(); }
 
     void ReturnKey();
     bool GetReservedKey(CPubKey &pubkey, bool internal = false);
     void KeepKey();
     void KeepScript() override { KeepKey(); }
 };
 
 /** RAII object to check and reserve a wallet rescan */
 class WalletRescanReserver {
 private:
     CWallet *m_wallet;
     bool m_could_reserve;
 
 public:
     explicit WalletRescanReserver(CWallet *w)
         : m_wallet(w), m_could_reserve(false) {}
 
     bool reserve() {
         assert(!m_could_reserve);
         std::lock_guard<std::mutex> lock(m_wallet->mutexScanning);
         if (m_wallet->fScanningWallet) {
             return false;
         }
         m_wallet->fScanningWallet = true;
         m_could_reserve = true;
         return true;
     }
 
     bool isReserved() const {
         return (m_could_reserve && m_wallet->fScanningWallet);
     }
 
     ~WalletRescanReserver() {
         std::lock_guard<std::mutex> lock(m_wallet->mutexScanning);
         if (m_could_reserve) {
             m_wallet->fScanningWallet = false;
         }
     }
 };
 
 // Calculate the size of the transaction assuming all signatures are max size
 // Use DummySignatureCreator, which inserts 71 byte signatures everywhere.
 // NOTE: this requires that all inputs must be in mapWallet (eg the tx should
 // be IsAllFromMe).
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet,
                                      bool use_max_sig = false)
     EXCLUSIVE_LOCKS_REQUIRED(wallet->cs_wallet);
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet,
                                      const std::vector<CTxOut> &txouts,
                                      bool use_max_sig = false);
 
 #endif // BITCOIN_WALLET_WALLET_H