diff --git a/src/chain.cpp b/src/chain.cpp
index 48ac80373..24b262b43 100644
--- a/src/chain.cpp
+++ b/src/chain.cpp
@@ -1,202 +1,205 @@
 // 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 <chain.h>
 
 /**
  * CChain implementation
  */
 void CChain::SetTip(CBlockIndex *pindex) {
     if (pindex == nullptr) {
         vChain.clear();
         return;
     }
 
     vChain.resize(pindex->nHeight + 1);
     while (pindex && vChain[pindex->nHeight] != pindex) {
         vChain[pindex->nHeight] = pindex;
         pindex = pindex->pprev;
     }
 }
 
 CBlockLocator CChain::GetLocator(const CBlockIndex *pindex) const {
     int nStep = 1;
     std::vector<BlockHash> vHave;
     vHave.reserve(32);
 
     if (!pindex) {
         pindex = Tip();
     }
     while (pindex) {
         vHave.push_back(pindex->GetBlockHash());
         // Stop when we have added the genesis block.
         if (pindex->nHeight == 0) {
             break;
         }
         // Exponentially larger steps back, plus the genesis block.
         int nHeight = std::max(pindex->nHeight - nStep, 0);
         if (Contains(pindex)) {
             // Use O(1) CChain index if possible.
             pindex = (*this)[nHeight];
         } else {
             // Otherwise, use O(log n) skiplist.
             pindex = pindex->GetAncestor(nHeight);
         }
         if (vHave.size() > 10) {
             nStep *= 2;
         }
     }
 
     return CBlockLocator(vHave);
 }
 
 const CBlockIndex *CChain::FindFork(const CBlockIndex *pindex) const {
     if (pindex == nullptr) {
         return nullptr;
     }
     if (pindex->nHeight > Height()) {
         pindex = pindex->GetAncestor(Height());
     }
     while (pindex && !Contains(pindex)) {
         pindex = pindex->pprev;
     }
     return pindex;
 }
 
-CBlockIndex *CChain::FindEarliestAtLeast(int64_t nTime) const {
-    std::vector<CBlockIndex *>::const_iterator lower =
-        std::lower_bound(vChain.begin(), vChain.end(), nTime,
-                         [](CBlockIndex *pBlock, const int64_t &time) -> bool {
-                             return pBlock->GetBlockTimeMax() < time;
-                         });
+CBlockIndex *CChain::FindEarliestAtLeast(int64_t nTime, int height) const {
+    std::pair<int64_t, int> blockparams = std::make_pair(nTime, height);
+    std::vector<CBlockIndex *>::const_iterator lower = std::lower_bound(
+        vChain.begin(), vChain.end(), blockparams,
+        [](CBlockIndex *pBlock,
+           const std::pair<int64_t, int> &blockparams) -> bool {
+            return pBlock->GetBlockTimeMax() < blockparams.first ||
+                   pBlock->nHeight < blockparams.second;
+        });
     return (lower == vChain.end() ? nullptr : *lower);
 }
 
 /** Turn the lowest '1' bit in the binary representation of a number into a '0'.
  */
 static inline int InvertLowestOne(int n) {
     return n & (n - 1);
 }
 
 /** Compute what height to jump back to with the CBlockIndex::pskip pointer. */
 static inline int GetSkipHeight(int height) {
     if (height < 2) {
         return 0;
     }
 
     // Determine which height to jump back to. Any number strictly lower than
     // height is acceptable, but the following expression seems to perform well
     // in simulations (max 110 steps to go back up to 2**18 blocks).
     return (height & 1) ? InvertLowestOne(InvertLowestOne(height - 1)) + 1
                         : InvertLowestOne(height);
 }
 
 const CBlockIndex *CBlockIndex::GetAncestor(int height) const {
     if (height > nHeight || height < 0) {
         return nullptr;
     }
 
     const CBlockIndex *pindexWalk = this;
     int heightWalk = nHeight;
     while (heightWalk > height) {
         int heightSkip = GetSkipHeight(heightWalk);
         int heightSkipPrev = GetSkipHeight(heightWalk - 1);
         if (pindexWalk->pskip != nullptr &&
             (heightSkip == height ||
              (heightSkip > height && !(heightSkipPrev < heightSkip - 2 &&
                                        heightSkipPrev >= height)))) {
             // Only follow pskip if pprev->pskip isn't better than pskip->pprev.
             pindexWalk = pindexWalk->pskip;
             heightWalk = heightSkip;
         } else {
             assert(pindexWalk->pprev);
             pindexWalk = pindexWalk->pprev;
             heightWalk--;
         }
     }
     return pindexWalk;
 }
 
 CBlockIndex *CBlockIndex::GetAncestor(int height) {
     return const_cast<CBlockIndex *>(
         const_cast<const CBlockIndex *>(this)->GetAncestor(height));
 }
 
 void CBlockIndex::BuildSkip() {
     if (pprev) {
         pskip = pprev->GetAncestor(GetSkipHeight(nHeight));
     }
 }
 
 arith_uint256 GetBlockProof(const CBlockIndex &block) {
     arith_uint256 bnTarget;
     bool fNegative;
     bool fOverflow;
     bnTarget.SetCompact(block.nBits, &fNegative, &fOverflow);
     if (fNegative || fOverflow || bnTarget == 0) {
         return 0;
     }
     // We need to compute 2**256 / (bnTarget+1), but we can't represent 2**256
     // as it's too large for an arith_uint256. However, as 2**256 is at least as
     // large as bnTarget+1, it is equal to ((2**256 - bnTarget - 1) /
     // (bnTarget+1)) + 1, or ~bnTarget / (bnTarget+1) + 1.
     return (~bnTarget / (bnTarget + 1)) + 1;
 }
 
 int64_t GetBlockProofEquivalentTime(const CBlockIndex &to,
                                     const CBlockIndex &from,
                                     const CBlockIndex &tip,
                                     const Consensus::Params &params) {
     arith_uint256 r;
     int sign = 1;
     if (to.nChainWork > from.nChainWork) {
         r = to.nChainWork - from.nChainWork;
     } else {
         r = from.nChainWork - to.nChainWork;
         sign = -1;
     }
     r = r * arith_uint256(params.nPowTargetSpacing) / GetBlockProof(tip);
     if (r.bits() > 63) {
         return sign * std::numeric_limits<int64_t>::max();
     }
     return sign * r.GetLow64();
 }
 
 /**
  * Find the last common ancestor two blocks have.
  * Both pa and pb must be non null.
  */
 const CBlockIndex *LastCommonAncestor(const CBlockIndex *pa,
                                       const CBlockIndex *pb) {
     if (pa->nHeight > pb->nHeight) {
         pa = pa->GetAncestor(pb->nHeight);
     } else if (pb->nHeight > pa->nHeight) {
         pb = pb->GetAncestor(pa->nHeight);
     }
 
     while (pa != pb && pa && pb) {
         if (pa->pskip && pb->pskip && pa->pskip != pb->pskip) {
             pa = pa->pskip;
             pb = pb->pskip;
             assert(pa->nHeight == pb->nHeight);
         } else {
             pa = pa->pprev;
             pb = pb->pprev;
         }
     }
 
     // Eventually all chain branches meet at the genesis block.
     assert(pa == pb);
     return pa;
 }
 
 bool AreOnTheSameFork(const CBlockIndex *pa, const CBlockIndex *pb) {
     if (pa->nHeight > pb->nHeight) {
         pa = pa->GetAncestor(pb->nHeight);
     } else if (pb->nHeight > pa->nHeight) {
         pb = pb->GetAncestor(pa->nHeight);
     }
     return pa == pb;
 }
diff --git a/src/chain.h b/src/chain.h
index cef3e566b..4e0b10de8 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -1,442 +1,443 @@
 // 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.
 
 #ifndef BITCOIN_CHAIN_H
 #define BITCOIN_CHAIN_H
 
 #include <arith_uint256.h>
 #include <blockstatus.h>
 #include <blockvalidity.h>
 #include <consensus/params.h>
 #include <crypto/common.h> // for ReadLE64
 #include <flatfile.h>
 #include <primitives/block.h>
 #include <sync.h>
 #include <tinyformat.h>
 #include <uint256.h>
 
 #include <unordered_map>
 #include <vector>
 
 /**
  * Maximum amount of time that a block timestamp is allowed to exceed the
  * current network-adjusted time before the block will be accepted.
  */
 static constexpr int64_t MAX_FUTURE_BLOCK_TIME = 2 * 60 * 60;
 
 /**
  * Timestamp window used as a grace period by code that compares external
  * timestamps (such as timestamps passed to RPCs, or wallet key creation times)
  * to block timestamps. This should be set at least as high as
  * MAX_FUTURE_BLOCK_TIME.
  */
 static constexpr int64_t TIMESTAMP_WINDOW = MAX_FUTURE_BLOCK_TIME;
 
 /**
  * Maximum gap between node time and block time used
  * for the "Catching up..." mode in GUI.
  *
  * Ref: https://github.com/bitcoin/bitcoin/pull/1026
  */
 static constexpr int64_t MAX_BLOCK_TIME_GAP = 90 * 60;
 
 /**
  * The block chain is a tree shaped structure starting with the genesis block at
  * the root, with each block potentially having multiple candidates to be the
  * next block. A blockindex may have multiple pprev pointing to it, but at most
  * one of them can be part of the currently active branch.
  */
 class CBlockIndex {
 public:
     //! pointer to the hash of the block, if any. Memory is owned by this
     //! CBlockIndex
     const BlockHash *phashBlock;
 
     //! pointer to the index of the predecessor of this block
     CBlockIndex *pprev;
 
     //! pointer to the index of some further predecessor of this block
     CBlockIndex *pskip;
 
     //! height of the entry in the chain. The genesis block has height 0
     int nHeight;
 
     //! Which # file this block is stored in (blk?????.dat)
     int nFile;
 
     //! Byte offset within blk?????.dat where this block's data is stored
     unsigned int nDataPos;
 
     //! Byte offset within rev?????.dat where this block's undo data is stored
     unsigned int nUndoPos;
 
     //! (memory only) Total amount of work (expected number of hashes) in the
     //! chain up to and including this block
     arith_uint256 nChainWork;
 
     //! Number of transactions in this block.
     //! Note: in a potential headers-first mode, this number cannot be relied
     //! upon
     unsigned int nTx;
 
     //! (memory only) Number of transactions in the chain up to and including
     //! this block.
     //! This value will be non-zero only if and only if transactions for this
     //! block and all its parents are available. Change to 64-bit type when
     //! necessary; won't happen before 2030
     unsigned int nChainTx;
 
     //! Verification status of this block. See enum BlockStatus
     BlockStatus nStatus;
 
     //! block header
     int32_t nVersion;
     uint256 hashMerkleRoot;
     uint32_t nTime;
     uint32_t nBits;
     uint32_t nNonce;
 
     //! (memory only) Sequential id assigned to distinguish order in which
     //! blocks are received.
     int32_t nSequenceId;
 
     //! (memory only) block header metadata
     uint64_t nTimeReceived;
 
     //! (memory only) Maximum nTime in the chain up to and including this block.
     unsigned int nTimeMax;
 
     void SetNull() {
         phashBlock = nullptr;
         pprev = nullptr;
         pskip = nullptr;
         nHeight = 0;
         nFile = 0;
         nDataPos = 0;
         nUndoPos = 0;
         nChainWork = arith_uint256();
         nTx = 0;
         nChainTx = 0;
         nStatus = BlockStatus();
         nSequenceId = 0;
         nTimeMax = 0;
 
         nVersion = 0;
         hashMerkleRoot = uint256();
         nTime = 0;
         nTimeReceived = 0;
         nBits = 0;
         nNonce = 0;
     }
 
     CBlockIndex() { SetNull(); }
 
     explicit CBlockIndex(const CBlockHeader &block) {
         SetNull();
 
         nVersion = block.nVersion;
         hashMerkleRoot = block.hashMerkleRoot;
         nTime = block.nTime;
         nTimeReceived = 0;
         nBits = block.nBits;
         nNonce = block.nNonce;
     }
 
     FlatFilePos GetBlockPos() const {
         FlatFilePos ret;
         if (nStatus.hasData()) {
             ret.nFile = nFile;
             ret.nPos = nDataPos;
         }
         return ret;
     }
 
     FlatFilePos GetUndoPos() const {
         FlatFilePos ret;
         if (nStatus.hasUndo()) {
             ret.nFile = nFile;
             ret.nPos = nUndoPos;
         }
         return ret;
     }
 
     CBlockHeader GetBlockHeader() const {
         CBlockHeader block;
         block.nVersion = nVersion;
         if (pprev) {
             block.hashPrevBlock = pprev->GetBlockHash();
         }
         block.hashMerkleRoot = hashMerkleRoot;
         block.nTime = nTime;
         block.nBits = nBits;
         block.nNonce = nNonce;
         return block;
     }
 
     BlockHash GetBlockHash() const { return *phashBlock; }
 
     /**
      * Check whether this block's and all previous blocks' transactions have
      * been downloaded (and stored to disk) at some point.
      *
      * Does not imply the transactions are consensus-valid (ConnectTip might
      * fail) Does not imply the transactions are still stored on disk.
      * (IsBlockPruned might return true)
      */
     bool HaveTxsDownloaded() const { return nChainTx != 0; }
 
     int64_t GetBlockTime() const { return int64_t(nTime); }
 
     int64_t GetBlockTimeMax() const { return int64_t(nTimeMax); }
 
     int64_t GetHeaderReceivedTime() const { return nTimeReceived; }
 
     int64_t GetReceivedTimeDiff() const {
         return GetHeaderReceivedTime() - GetBlockTime();
     }
 
     static constexpr int nMedianTimeSpan = 11;
 
     int64_t GetMedianTimePast() const {
         int64_t pmedian[nMedianTimeSpan];
         int64_t *pbegin = &pmedian[nMedianTimeSpan];
         int64_t *pend = &pmedian[nMedianTimeSpan];
 
         const CBlockIndex *pindex = this;
         for (int i = 0; i < nMedianTimeSpan && pindex;
              i++, pindex = pindex->pprev) {
             *(--pbegin) = pindex->GetBlockTime();
         }
 
         std::sort(pbegin, pend);
         return pbegin[(pend - pbegin) / 2];
     }
 
     std::string ToString() const {
         return strprintf(
             "CBlockIndex(pprev=%p, nHeight=%d, merkle=%s, hashBlock=%s)", pprev,
             nHeight, hashMerkleRoot.ToString(), GetBlockHash().ToString());
     }
 
     //! Check whether this block index entry is valid up to the passed validity
     //! level.
     bool IsValid(enum BlockValidity nUpTo = BlockValidity::TRANSACTIONS) const {
         return nStatus.isValid(nUpTo);
     }
 
     //! Raise the validity level of this block index entry.
     //! Returns true if the validity was changed.
     bool RaiseValidity(enum BlockValidity nUpTo) {
         // Only validity flags allowed.
         if (nStatus.isInvalid()) {
             return false;
         }
 
         if (nStatus.getValidity() >= nUpTo) {
             return false;
         }
 
         nStatus = nStatus.withValidity(nUpTo);
         return true;
     }
 
     //! Build the skiplist pointer for this entry.
     void BuildSkip();
 
     //! Efficiently find an ancestor of this block.
     CBlockIndex *GetAncestor(int height);
     const CBlockIndex *GetAncestor(int height) const;
 };
 
 /**
  * Maintain a map of CBlockIndex for all known headers.
  */
 struct BlockHasher {
     // this used to call `GetCheapHash()` in uint256, which was later moved; the
     // cheap hash function simply calls ReadLE64() however, so the end result is
     // identical
     size_t operator()(const BlockHash &hash) const {
         return ReadLE64(hash.begin());
     }
 };
 
 extern RecursiveMutex cs_main;
 typedef std::unordered_map<BlockHash, CBlockIndex *, BlockHasher> BlockMap;
 extern BlockMap &mapBlockIndex GUARDED_BY(cs_main);
 
 inline CBlockIndex *LookupBlockIndex(const BlockHash &hash) {
     AssertLockHeld(cs_main);
     BlockMap::const_iterator it = mapBlockIndex.find(hash);
     return it == mapBlockIndex.end() ? nullptr : it->second;
 }
 
 arith_uint256 GetBlockProof(const CBlockIndex &block);
 
 /**
  * Return the time it would take to redo the work difference between from and
  * to, assuming the current hashrate corresponds to the difficulty at tip, in
  * seconds.
  */
 int64_t GetBlockProofEquivalentTime(const CBlockIndex &to,
                                     const CBlockIndex &from,
                                     const CBlockIndex &tip,
                                     const Consensus::Params &);
 /**
  * Find the forking point between two chain tips.
  */
 const CBlockIndex *LastCommonAncestor(const CBlockIndex *pa,
                                       const CBlockIndex *pb);
 
 /**
  * Check if two block index are on the same fork.
  */
 bool AreOnTheSameFork(const CBlockIndex *pa, const CBlockIndex *pb);
 
 /** Used to marshal pointers into hashes for db storage. */
 class CDiskBlockIndex : public CBlockIndex {
 public:
     BlockHash hashPrev;
 
     CDiskBlockIndex() { hashPrev = BlockHash(); }
 
     explicit CDiskBlockIndex(const CBlockIndex *pindex) : CBlockIndex(*pindex) {
         hashPrev = (pprev ? pprev->GetBlockHash() : BlockHash());
     }
 
     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(VARINT(_nVersion, VarIntMode::NONNEGATIVE_SIGNED));
         }
 
         READWRITE(VARINT(nHeight, VarIntMode::NONNEGATIVE_SIGNED));
         READWRITE(nStatus);
         READWRITE(VARINT(nTx));
         if (nStatus.hasData() || nStatus.hasUndo()) {
             READWRITE(VARINT(nFile, VarIntMode::NONNEGATIVE_SIGNED));
         }
         if (nStatus.hasData()) {
             READWRITE(VARINT(nDataPos));
         }
         if (nStatus.hasUndo()) {
             READWRITE(VARINT(nUndoPos));
         }
 
         // block header
         READWRITE(this->nVersion);
         READWRITE(hashPrev);
         READWRITE(hashMerkleRoot);
         READWRITE(nTime);
         READWRITE(nBits);
         READWRITE(nNonce);
     }
 
     BlockHash GetBlockHash() const {
         CBlockHeader block;
         block.nVersion = nVersion;
         block.hashPrevBlock = hashPrev;
         block.hashMerkleRoot = hashMerkleRoot;
         block.nTime = nTime;
         block.nBits = nBits;
         block.nNonce = nNonce;
         return block.GetHash();
     }
 
     std::string ToString() const {
         std::string str = "CDiskBlockIndex(";
         str += CBlockIndex::ToString();
         str += strprintf("\n                hashBlock=%s, hashPrev=%s)",
                          GetBlockHash().ToString(), hashPrev.ToString());
         return str;
     }
 };
 
 /**
  * An in-memory indexed chain of blocks.
  */
 class CChain {
 private:
     std::vector<CBlockIndex *> vChain;
 
 public:
     /**
      * Returns the index entry for the genesis block of this chain, or nullptr
      * if none.
      */
     CBlockIndex *Genesis() const {
         return vChain.size() > 0 ? vChain[0] : nullptr;
     }
 
     /**
      * Returns the index entry for the tip of this chain, or nullptr if none.
      */
     CBlockIndex *Tip() const {
         return vChain.size() > 0 ? vChain[vChain.size() - 1] : nullptr;
     }
 
     /**
      * Returns the index entry at a particular height in this chain, or nullptr
      * if no such height exists.
      */
     CBlockIndex *operator[](int nHeight) const {
         if (nHeight < 0 || nHeight >= (int)vChain.size()) {
             return nullptr;
         }
         return vChain[nHeight];
     }
 
     /** Compare two chains efficiently. */
     friend bool operator==(const CChain &a, const CChain &b) {
         return a.vChain.size() == b.vChain.size() &&
                a.vChain[a.vChain.size() - 1] == b.vChain[b.vChain.size() - 1];
     }
 
     /** Efficiently check whether a block is present in this chain. */
     bool Contains(const CBlockIndex *pindex) const {
         return (*this)[pindex->nHeight] == pindex;
     }
 
     /**
      * Find the successor of a block in this chain, or nullptr if the given
      * index is not found or is the tip.
      */
     CBlockIndex *Next(const CBlockIndex *pindex) const {
         if (!Contains(pindex)) {
             return nullptr;
         }
 
         return (*this)[pindex->nHeight + 1];
     }
 
     /**
      * Return the maximal height in the chain. Is equal to chain.Tip() ?
      * chain.Tip()->nHeight : -1.
      */
     int Height() const { return vChain.size() - 1; }
 
     /** Set/initialize a chain with a given tip. */
     void SetTip(CBlockIndex *pindex);
 
     /**
      * Return a CBlockLocator that refers to a block in this chain (by default
      * the tip).
      */
     CBlockLocator GetLocator(const CBlockIndex *pindex = nullptr) const;
 
     /**
      * Find the last common block between this chain and a block index entry.
      */
     const CBlockIndex *FindFork(const CBlockIndex *pindex) const;
 
     /**
-     * Find the earliest block with timestamp equal or greater than the given.
+     * Find the earliest block with timestamp equal or greater than the given
+     * time and height equal or greater than the given height.
      */
-    CBlockIndex *FindEarliestAtLeast(int64_t nTime) const;
+    CBlockIndex *FindEarliestAtLeast(int64_t nTime, int height) const;
 };
 
 #endif // BITCOIN_CHAIN_H
diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 18067e3f3..a41b9ed8e 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -1,403 +1,390 @@
 // 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 <interfaces/handler.h>
 #include <interfaces/wallet.h>
 #include <net.h>
 #include <node/coin.h>
 #include <policy/mempool.h>
 #include <policy/policy.h>
 #include <policy/settings.h>
 #include <primitives/block.h>
 #include <primitives/blockhash.h>
 #include <primitives/transaction.h>
 #include <protocol.h>
 #include <rpc/protocol.h>
 #include <rpc/server.h>
 #include <shutdown.h>
 #include <sync.h>
 #include <threadsafety.h>
 #include <timedata.h>
 #include <txmempool.h>
 #include <ui_interface.h>
 #include <univalue.h>
 #include <util/system.h>
 #include <validation.h>
 #include <validationinterface.h>
 
 #include <memory>
 #include <utility>
 
 namespace interfaces {
 namespace {
 
     class LockImpl : public Chain::Lock, public UniqueLock<RecursiveMutex> {
         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);
+        Optional<int>
+        findFirstBlockWithTimeAndHeight(int64_t time, int height,
+                                        BlockHash *hash) override {
+            CBlockIndex *block =
+                ::ChainActive().FindEarliestAtLeast(time, height);
             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 getTipLocator() 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;
         }
         bool contextualCheckTransactionForCurrentBlock(
             const Consensus::Params &params, const CTransaction &tx,
             CValidationState &state) override {
             LockAnnotation lock(::cs_main);
             return ContextualCheckTransactionForCurrentBlock(params, tx, state);
         }
         bool submitToMemoryPool(const Config &config, CTransactionRef tx,
                                 Amount absurd_fee,
                                 CValidationState &state) override {
             LockAnnotation lock(::cs_main);
             return AcceptToMemoryPool(config, ::g_mempool, state, tx,
                                       nullptr /* missing inputs */,
                                       false /* bypass limits */, absurd_fee);
         }
 
         using UniqueLock::UniqueLock;
     };
 
     class NotificationsHandlerImpl : public Handler, CValidationInterface {
     public:
         explicit NotificationsHandlerImpl(Chain &chain,
                                           Chain::Notifications &notifications)
             : m_chain(chain), m_notifications(&notifications) {
             RegisterValidationInterface(this);
         }
         ~NotificationsHandlerImpl() override { disconnect(); }
         void disconnect() override {
             if (m_notifications) {
                 m_notifications = nullptr;
                 UnregisterValidationInterface(this);
             }
         }
         void TransactionAddedToMempool(const CTransactionRef &tx) override {
             m_notifications->TransactionAddedToMempool(tx);
         }
         void TransactionRemovedFromMempool(const CTransactionRef &tx) override {
             m_notifications->TransactionRemovedFromMempool(tx);
         }
         void BlockConnected(
             const std::shared_ptr<const CBlock> &block,
             const CBlockIndex *index,
             const std::vector<CTransactionRef> &tx_conflicted) override {
             m_notifications->BlockConnected(*block, tx_conflicted);
         }
         void
         BlockDisconnected(const std::shared_ptr<const CBlock> &block) override {
             m_notifications->BlockDisconnected(*block);
         }
         void UpdatedBlockTip(const CBlockIndex *index,
                              const CBlockIndex *fork_index,
                              bool is_ibd) override {
             m_notifications->UpdatedBlockTip();
         }
         void ChainStateFlushed(const CBlockLocator &locator) override {
             m_notifications->ChainStateFlushed(locator);
         }
         Chain &m_chain;
         Chain::Notifications *m_notifications;
     };
 
     class RpcHandlerImpl : public Handler {
     public:
         RpcHandlerImpl(const CRPCCommand &command)
             : m_command(command), m_wrapped_command(&command) {
             m_command.actor = [this](Config &config,
                                      const JSONRPCRequest &request,
                                      UniValue &result, bool last_handler) {
                 if (!m_wrapped_command) {
                     return false;
                 }
                 try {
                     return m_wrapped_command->actor(config, request, result,
                                                     last_handler);
                 } catch (const UniValue &e) {
                     // If this is not the last handler and a wallet not found
                     // exception was thrown, return false so the next handler
                     // can try to handle the request. Otherwise, reraise the
                     // exception.
                     if (!last_handler) {
                         const UniValue &code = e["code"];
                         if (code.isNum() &&
                             code.get_int() == RPC_WALLET_NOT_FOUND) {
                             return false;
                         }
                     }
                     throw;
                 }
             };
             ::tableRPC.appendCommand(m_command.name, &m_command);
         }
 
         void disconnect() override final {
             if (m_wrapped_command) {
                 m_wrapped_command = nullptr;
                 ::tableRPC.removeCommand(m_command.name, &m_command);
             }
         }
 
         ~RpcHandlerImpl() override { disconnect(); }
 
         CRPCCommand m_command;
         const CRPCCommand *m_wrapped_command;
     };
 
     class ChainImpl : public Chain {
     public:
         std::unique_ptr<Chain::Lock> lock(bool try_lock) override {
             auto lock = std::make_unique<LockImpl>(
                 ::cs_main, "cs_main", __FILE__, __LINE__, try_lock);
             if (try_lock && lock && !*lock) {
                 return {};
             }
             // Temporary to avoid CWG 1579
             std::unique_ptr<Chain::Lock> result = std::move(lock);
             return result;
         }
         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;
         }
         void findCoins(std::map<COutPoint, Coin> &coins) override {
             return FindCoins(coins);
         }
         double guessVerificationProgress(const BlockHash &block_hash) override {
             LOCK(cs_main);
             return GuessVerificationProgress(Params().TxData(),
                                              LookupBlockIndex(block_hash));
         }
         bool hasDescendantsInMempool(const TxId &txid) override {
             LOCK(::g_mempool.cs);
             auto it = ::g_mempool.GetIter(txid);
             return it && (*it)->GetCountWithDescendants() > 1;
         }
         void relayTransaction(const TxId &txid) override {
             CInv inv(MSG_TX, txid);
             g_connman->ForEachNode(
                 [&inv](CNode *node) { node->PushInventory(inv); });
         }
         void getTransactionAncestry(const TxId &txid, size_t &ancestors,
                                     size_t &descendants) override {
             ::g_mempool.GetTransactionAncestry(txid, ancestors, descendants);
         }
         bool checkChainLimits(const CTransactionRef &tx) override {
             LockPoints lp;
             CTxMemPoolEntry entry(tx, Amount(), 0, 0, false, 0, lp);
             CTxMemPool::setEntries ancestors;
             auto limit_ancestor_count =
                 gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT);
             auto limit_ancestor_size =
                 gArgs.GetArg("-limitancestorsize",
                              DEFAULT_ANCESTOR_SIZE_LIMIT) *
                 1000;
             auto limit_descendant_count =
                 gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT);
             auto limit_descendant_size =
                 gArgs.GetArg("-limitdescendantsize",
                              DEFAULT_DESCENDANT_SIZE_LIMIT) *
                 1000;
             std::string unused_error_string;
             LOCK(::g_mempool.cs);
             return ::g_mempool.CalculateMemPoolAncestors(
                 entry, ancestors, limit_ancestor_count, limit_ancestor_size,
                 limit_descendant_count, limit_descendant_size,
                 unused_error_string);
         }
         CFeeRate estimateFee() const override {
             return ::g_mempool.estimateFee();
         }
         CFeeRate relayMinFee() override { return ::minRelayTxFee; }
         CFeeRate relayDustFee() override { return ::dustRelayFee; }
         Amount maxTxFee() override { return ::maxTxFee; }
         bool getPruneMode() override { return ::fPruneMode; }
         bool p2pEnabled() override { return g_connman != nullptr; }
         bool isReadyToBroadcast() override {
             return !::fImporting && !::fReindex && !isInitialBlockDownload();
         }
         bool isInitialBlockDownload() override {
             return ::ChainstateActive().IsInitialBlockDownload();
         }
         bool shutdownRequested() override { return ShutdownRequested(); }
         int64_t getAdjustedTime() override { return GetAdjustedTime(); }
         void initMessage(const std::string &message) override {
             ::uiInterface.InitMessage(message);
         }
         void initWarning(const std::string &message) override {
             InitWarning(message);
         }
         void initError(const std::string &message) override {
             InitError(message);
         }
         void loadWallet(std::unique_ptr<Wallet> wallet) override {
             ::uiInterface.LoadWallet(wallet);
         }
         void showProgress(const std::string &title, int progress,
                           bool resume_possible) override {
             ::uiInterface.ShowProgress(title, progress, resume_possible);
         }
         std::unique_ptr<Handler>
         handleNotifications(Notifications &notifications) override {
             return std::make_unique<NotificationsHandlerImpl>(*this,
                                                               notifications);
         }
         void waitForNotifications() override {
             SyncWithValidationInterfaceQueue();
         }
         std::unique_ptr<Handler>
         handleRpc(const CRPCCommand &command) override {
             return std::make_unique<RpcHandlerImpl>(command);
         }
         bool rpcEnableDeprecated(const std::string &method) override {
             return IsDeprecatedRPCEnabled(gArgs, method);
         }
         void rpcRunLater(const std::string &name, std::function<void()> fn,
                          int64_t seconds) override {
             RPCRunLater(name, std::move(fn), seconds);
         }
         int rpcSerializationFlags() override { return RPCSerializationFlags(); }
         void requestMempoolTransactions(Notifications &notifications) override {
             LOCK2(::cs_main, ::g_mempool.cs);
             for (const CTxMemPoolEntry &entry : ::g_mempool.mapTx) {
                 notifications.TransactionAddedToMempool(entry.GetSharedTx());
             }
         }
     };
 
 } // 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 a6fa57662..07fd6ed1b 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -1,341 +1,333 @@
 // 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 <primitives/transaction.h>
 #include <primitives/txid.h>
 
 #include <cstddef>
 #include <cstdint>
 #include <memory>
 #include <string>
 #include <vector>
 
 struct BlockHash;
 class CBlock;
 struct CBlockLocator;
 class CChainParams;
 class Coin;
 class Config;
 class CRPCCommand;
 class CScheduler;
 class CValidationState;
 namespace Consensus {
 struct Params;
 }
 
 namespace interfaces {
 
 class Handler;
 class Wallet;
 
 //! Interface giving clients (wallet processes, maybe other analysis tools in
 //! the future) ability to access to the chain state, receive notifications,
 //! estimate fees, and submit transactions.
 //!
 //! TODO: Current chain methods are too low level, exposing too much of the
 //! internal workings of the bitcoin node, and not being very convenient to use.
 //! Chain methods should be cleaned up and simplified over time. Examples:
 //!
 //! * The Chain::lock() method, which lets clients delay chain tip updates
 //!   should be removed when clients are able to respond to updates
 //!   asynchronously
 //!   (https://github.com/bitcoin/bitcoin/pull/10973#issuecomment-380101269).
 //!
 //! * The isPotentialTip() and waitForNotifications() methods are too low-level
 //!   and should be replaced with a higher level
 //!   waitForNotificationsUpTo(block_hash) method that the wallet can call
 //!   instead
 //!   (https://github.com/bitcoin/bitcoin/pull/10973#discussion_r266995234).
 //!
 //! * The relayTransactions() and submitToMemoryPool() methods could be replaced
 //!   with a higher-level broadcastTransaction method
 //!   (https://github.com/bitcoin/bitcoin/pull/14978#issuecomment-459373984).
 //!
 //! * The initMessages() and loadWallet() methods which the wallet uses to send
 //!   notifications to the GUI should go away when GUI and wallet can directly
 //!   communicate with each other without going through the node
 //!   (https://github.com/bitcoin/bitcoin/pull/15288#discussion_r253321096).
 //!
 //! * The handleRpc, registerRpcs, rpcEnableDeprecated methods and other RPC
 //!   methods can go away if wallets listen for HTTP requests on their own
 //!   ports instead of registering to handle requests on the node HTTP port.
 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
+        //! or greater than the given time and height equal or greater than the
+        //! given height, or nullopt if there is no block with a high enough
+        //! timestamp and height. 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;
+        virtual Optional<int>
+        findFirstBlockWithTimeAndHeight(int64_t time, int height,
+                                        BlockHash *hash) = 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 getTipLocator() = 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;
 
         //! Check if transaction will be final given chain height current time.
         virtual bool contextualCheckTransactionForCurrentBlock(
             const Consensus::Params &params, const CTransaction &tx,
             CValidationState &state) = 0;
 
         //! Add transaction to memory pool if the transaction fee is below the
         //! amount specified by absurd_fee (as a safeguard). */
         virtual bool submitToMemoryPool(const Config &config,
                                         CTransactionRef tx, Amount absurd_fee,
                                         CValidationState &state) = 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 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;
 
     //! Look up unspent output information. Returns coins in the mempool and in
     //! the current chain UTXO set. Iterates through all the keys in the map and
     //! populates the values.
     virtual void findCoins(std::map<COutPoint, Coin> &coins) = 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;
 
     //! Check if transaction has descendants in mempool.
     virtual bool hasDescendantsInMempool(const TxId &txid) = 0;
 
     //! Calculate mempool ancestor and descendant counts for the given
     //! transaction.
     virtual void getTransactionAncestry(const TxId &txid, size_t &ancestors,
                                         size_t &descendants) = 0;
 
     //! Relay transaction.
     virtual void relayTransaction(const TxId &txid) = 0;
 
     //! Check if transaction will pass the mempool's chain limits.
     virtual bool checkChainLimits(const CTransactionRef &tx) = 0;
 
     //! Estimate fee
     virtual CFeeRate estimateFee() const = 0;
 
     //! Relay current minimum fee (from -minrelaytxfee settings).
     virtual CFeeRate relayMinFee() = 0;
 
     //! Relay dust fee setting (-dustrelayfee), reflecting lowest rate it's
     //! economical to spend.
     virtual CFeeRate relayDustFee() = 0;
 
     //! Get node max tx fee setting (-maxtxfee).
     //! This could be replaced by a per-wallet max fee, as proposed at
     //! https://github.com/bitcoin/bitcoin/issues/15355
     //! But for the time being, wallets call this to access the node setting.
     virtual Amount maxTxFee() = 0;
 
     //! Check if pruning is enabled.
     virtual bool getPruneMode() = 0;
 
     //! Check if p2p enabled.
     virtual bool p2pEnabled() = 0;
 
     //! Check if the node is ready to broadcast transactions.
     virtual bool isReadyToBroadcast() = 0;
 
     //! Check if in IBD.
     virtual bool isInitialBlockDownload() = 0;
 
     //! Check if shutdown requested.
     virtual bool shutdownRequested() = 0;
 
     //! Get adjusted time.
     virtual int64_t getAdjustedTime() = 0;
 
     //! Send init message.
     virtual void initMessage(const std::string &message) = 0;
 
     //! Send init warning.
     virtual void initWarning(const std::string &message) = 0;
 
     //! Send init error.
     virtual void initError(const std::string &message) = 0;
 
     //! Send wallet load notification to the GUI.
     virtual void loadWallet(std::unique_ptr<Wallet> wallet) = 0;
 
     //! Send progress indicator.
     virtual void showProgress(const std::string &title, int progress,
                               bool resume_possible) = 0;
 
     //! Chain notifications.
     class Notifications {
     public:
         virtual ~Notifications() {}
         virtual void TransactionAddedToMempool(const CTransactionRef &tx) {}
         virtual void TransactionRemovedFromMempool(const CTransactionRef &ptx) {
         }
         virtual void
         BlockConnected(const CBlock &block,
                        const std::vector<CTransactionRef> &tx_conflicted) {}
         virtual void BlockDisconnected(const CBlock &block) {}
         virtual void UpdatedBlockTip() {}
         virtual void ChainStateFlushed(const CBlockLocator &locator) {}
     };
 
     //! Register handler for notifications.
     virtual std::unique_ptr<Handler>
     handleNotifications(Notifications &notifications) = 0;
 
     //! Wait for pending notifications to be handled.
     virtual void waitForNotifications() = 0;
 
     //! Register handler for RPC. Command is not copied, so reference
     //! needs to remain valid until Handler is disconnected.
     virtual std::unique_ptr<Handler> handleRpc(const CRPCCommand &command) = 0;
 
     //! Check if deprecated RPC is enabled.
     virtual bool rpcEnableDeprecated(const std::string &method) = 0;
 
     //! Run function after given number of seconds. Cancel any previous calls
     //! with same name.
     virtual void rpcRunLater(const std::string &name, std::function<void()> fn,
                              int64_t seconds) = 0;
 
     //! Current RPC serialization flags.
     virtual int rpcSerializationFlags() = 0;
 
     //! Synchronously send TransactionAddedToMempool notifications about all
     //! current mempool transactions to the specified handler and return after
     //! the last one is sent. These notifications aren't coordinated with async
     //! notifications sent by handleNotifications, so out of date async
     //! notifications from handleNotifications can arrive during and after
     //! synchronous notifications from requestMempoolTransactions. Clients need
     //! to be prepared to handle this by ignoring notifications about unknown
     //! removed transactions and already added new transactions.
     virtual void requestMempoolTransactions(Notifications &notifications) = 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/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 4b771b273..753002589 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1,2721 +1,2721 @@
 // Copyright (c) 2010 Satoshi Nakamoto
 // Copyright (c) 2009-2019 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 <rpc/blockchain.h>
 
 #include <amount.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <checkpoints.h>
 #include <coins.h>
 #include <config.h>
 #include <consensus/validation.h>
 #include <core_io.h>
 #include <hash.h>
 #include <index/txindex.h>
 #include <key_io.h>
 #include <node/coinstats.h>
 #include <policy/policy.h>
 #include <primitives/transaction.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
 #include <script/descriptor.h>
 #include <streams.h>
 #include <sync.h>
 #include <txdb.h>
 #include <txmempool.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <util/validation.h>
 #include <validation.h>
 #include <validationinterface.h>
 #include <versionbitsinfo.h> // For VersionBitsDeploymentInfo
 #include <warnings.h>
 
 #include <boost/thread/thread.hpp> // boost::thread::interrupt
 
 #include <condition_variable>
 #include <cstdint>
 #include <memory>
 #include <mutex>
 
 struct CUpdatedBlock {
     uint256 hash;
     int height;
 };
 
 static Mutex cs_blockchange;
 static std::condition_variable cond_blockchange;
 static CUpdatedBlock latestblock;
 
 /**
  * Calculate the difficulty for a given block index.
  */
 double GetDifficulty(const CBlockIndex *blockindex) {
     assert(blockindex);
 
     int nShift = (blockindex->nBits >> 24) & 0xff;
     double dDiff = double(0x0000ffff) / double(blockindex->nBits & 0x00ffffff);
 
     while (nShift < 29) {
         dDiff *= 256.0;
         nShift++;
     }
     while (nShift > 29) {
         dDiff /= 256.0;
         nShift--;
     }
 
     return dDiff;
 }
 
 static int ComputeNextBlockAndDepth(const CBlockIndex *tip,
                                     const CBlockIndex *blockindex,
                                     const CBlockIndex *&next) {
     next = tip->GetAncestor(blockindex->nHeight + 1);
     if (next && next->pprev == blockindex) {
         return tip->nHeight - blockindex->nHeight + 1;
     }
     next = nullptr;
     return blockindex == tip ? 1 : -1;
 }
 
 UniValue blockheaderToJSON(const CBlockIndex *tip,
                            const CBlockIndex *blockindex) {
     UniValue result(UniValue::VOBJ);
     result.pushKV("hash", blockindex->GetBlockHash().GetHex());
     const CBlockIndex *pnext;
     int confirmations = ComputeNextBlockAndDepth(tip, blockindex, pnext);
     result.pushKV("confirmations", confirmations);
     result.pushKV("height", blockindex->nHeight);
     result.pushKV("version", blockindex->nVersion);
     result.pushKV("versionHex", strprintf("%08x", blockindex->nVersion));
     result.pushKV("merkleroot", blockindex->hashMerkleRoot.GetHex());
     result.pushKV("time", int64_t(blockindex->nTime));
     result.pushKV("mediantime", int64_t(blockindex->GetMedianTimePast()));
     result.pushKV("nonce", uint64_t(blockindex->nNonce));
     result.pushKV("bits", strprintf("%08x", blockindex->nBits));
     result.pushKV("difficulty", GetDifficulty(blockindex));
     result.pushKV("chainwork", blockindex->nChainWork.GetHex());
     result.pushKV("nTx", uint64_t(blockindex->nTx));
 
     if (blockindex->pprev) {
         result.pushKV("previousblockhash",
                       blockindex->pprev->GetBlockHash().GetHex());
     }
     if (pnext) {
         result.pushKV("nextblockhash", pnext->GetBlockHash().GetHex());
     }
     return result;
 }
 
 UniValue blockToJSON(const CBlock &block, const CBlockIndex *tip,
                      const CBlockIndex *blockindex, bool txDetails) {
     UniValue result(UniValue::VOBJ);
     result.pushKV("hash", blockindex->GetBlockHash().GetHex());
     const CBlockIndex *pnext;
     int confirmations = ComputeNextBlockAndDepth(tip, blockindex, pnext);
     result.pushKV("confirmations", confirmations);
     result.pushKV("size", (int)::GetSerializeSize(block, PROTOCOL_VERSION));
     result.pushKV("height", blockindex->nHeight);
     result.pushKV("version", block.nVersion);
     result.pushKV("versionHex", strprintf("%08x", block.nVersion));
     result.pushKV("merkleroot", block.hashMerkleRoot.GetHex());
     UniValue txs(UniValue::VARR);
     for (const auto &tx : block.vtx) {
         if (txDetails) {
             UniValue objTx(UniValue::VOBJ);
             TxToUniv(*tx, uint256(), objTx, true, RPCSerializationFlags());
             txs.push_back(objTx);
         } else {
             txs.push_back(tx->GetId().GetHex());
         }
     }
     result.pushKV("tx", txs);
     result.pushKV("time", block.GetBlockTime());
     result.pushKV("mediantime", int64_t(blockindex->GetMedianTimePast()));
     result.pushKV("nonce", uint64_t(block.nNonce));
     result.pushKV("bits", strprintf("%08x", block.nBits));
     result.pushKV("difficulty", GetDifficulty(blockindex));
     result.pushKV("chainwork", blockindex->nChainWork.GetHex());
     result.pushKV("nTx", uint64_t(blockindex->nTx));
 
     if (blockindex->pprev) {
         result.pushKV("previousblockhash",
                       blockindex->pprev->GetBlockHash().GetHex());
     }
     if (pnext) {
         result.pushKV("nextblockhash", pnext->GetBlockHash().GetHex());
     }
     return result;
 }
 
 static UniValue getblockcount(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(RPCHelpMan{
             "getblockcount",
             "\nReturns the number of blocks in the longest blockchain.\n",
             {},
             RPCResult{"n    (numeric) The current block count\n"},
             RPCExamples{HelpExampleCli("getblockcount", "") +
                         HelpExampleRpc("getblockcount", "")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
     return ::ChainActive().Height();
 }
 
 static UniValue getbestblockhash(const Config &config,
                                  const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(RPCHelpMan{
             "getbestblockhash",
             "\nReturns the hash of the best (tip) block in the "
             "longest blockchain.\n",
             {},
             RPCResult{"\"hex\"      (string) the block hash, hex-encoded\n"},
             RPCExamples{HelpExampleCli("getbestblockhash", "") +
                         HelpExampleRpc("getbestblockhash", "")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
     return ::ChainActive().Tip()->GetBlockHash().GetHex();
 }
 
 UniValue getfinalizedblockhash(const Config &config,
                                const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(RPCHelpMan{
             "getfinalizedblockhash",
             "\nReturns the hash of the currently finalized block\n",
             {},
             RPCResult{"\"hex\"      (string) the block hash hex-encoded\n"},
             RPCExamples{HelpExampleCli("getfinalizedblockhash", "") +
                         HelpExampleRpc("getfinalizedblockhash", "")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
     const CBlockIndex *blockIndexFinalized = GetFinalizedBlock();
     if (blockIndexFinalized) {
         return blockIndexFinalized->GetBlockHash().GetHex();
     }
     return UniValue(UniValue::VSTR);
 }
 
 void RPCNotifyBlockChange(bool ibd, const CBlockIndex *pindex) {
     if (pindex) {
         std::lock_guard<std::mutex> lock(cs_blockchange);
         latestblock.hash = pindex->GetBlockHash();
         latestblock.height = pindex->nHeight;
     }
     cond_blockchange.notify_all();
 }
 
 static UniValue waitfornewblock(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(RPCHelpMan{
             "waitfornewblock",
             "\nWaits for a specific new block and returns useful "
             "info about it.\n"
             "\nReturns the current block on timeout or exit.\n",
             {
                 {"timeout", RPCArg::Type::NUM, /* default */ "0",
                  "Time in milliseconds to wait for a response. 0 indicates no "
                  "timeout."},
             },
             RPCResult{"{                           (json object)\n"
                       "  \"hash\" : {       (string) The blockhash\n"
                       "  \"height\" : {     (int) Block height\n"
                       "}\n"},
             RPCExamples{HelpExampleCli("waitfornewblock", "1000") +
                         HelpExampleRpc("waitfornewblock", "1000")},
         }
                                      .ToString());
     }
     int timeout = 0;
     if (!request.params[0].isNull()) {
         timeout = request.params[0].get_int();
     }
 
     CUpdatedBlock block;
     {
         WAIT_LOCK(cs_blockchange, lock);
         block = latestblock;
         if (timeout) {
             cond_blockchange.wait_for(
                 lock, std::chrono::milliseconds(timeout), [&block] {
                     return latestblock.height != block.height ||
                            latestblock.hash != block.hash || !IsRPCRunning();
                 });
         } else {
             cond_blockchange.wait(lock, [&block] {
                 return latestblock.height != block.height ||
                        latestblock.hash != block.hash || !IsRPCRunning();
             });
         }
         block = latestblock;
     }
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("hash", block.hash.GetHex());
     ret.pushKV("height", block.height);
     return ret;
 }
 
 static UniValue waitforblock(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(RPCHelpMan{
             "waitforblock",
             "\nWaits for a specific new block and returns useful "
             "info about it.\n"
             "\nReturns the current block on timeout or exit.\n",
             {
                 {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "Block hash to wait for."},
                 {"timeout", RPCArg::Type::NUM, /* default */ "0",
                  "Time in milliseconds to wait for a response. 0 "
                  "indicates no timeout."},
             },
             RPCResult{"{                           (json object)\n"
                       "  \"hash\" : {       (string) The blockhash\n"
                       "  \"height\" : {     (int) Block height\n"
                       "}\n"},
             RPCExamples{HelpExampleCli("waitforblock",
                                        "\"0000000000079f8ef3d2c688c244eb7a4"
                                        "570b24c9ed7b4a8c619eb02596f8862\", "
                                        "1000") +
                         HelpExampleRpc("waitforblock",
                                        "\"0000000000079f8ef3d2c688c244eb7a4"
                                        "570b24c9ed7b4a8c619eb02596f8862\", "
                                        "1000")},
         }
                                      .ToString());
     }
 
     int timeout = 0;
 
     BlockHash hash(ParseHashV(request.params[0], "blockhash"));
 
     if (!request.params[1].isNull()) {
         timeout = request.params[1].get_int();
     }
 
     CUpdatedBlock block;
     {
         WAIT_LOCK(cs_blockchange, lock);
         if (timeout) {
             cond_blockchange.wait_for(
                 lock, std::chrono::milliseconds(timeout), [&hash] {
                     return latestblock.hash == hash || !IsRPCRunning();
                 });
         } else {
             cond_blockchange.wait(lock, [&hash] {
                 return latestblock.hash == hash || !IsRPCRunning();
             });
         }
         block = latestblock;
     }
 
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("hash", block.hash.GetHex());
     ret.pushKV("height", block.height);
     return ret;
 }
 
 static UniValue waitforblockheight(const Config &config,
                                    const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(RPCHelpMan{
             "waitforblockheight",
             "\nWaits for (at least) block height and returns the "
             "height and hash\nof the current tip.\n"
             "\nReturns the current block on timeout or exit.\n",
             {
                 {"height", RPCArg::Type::NUM, RPCArg::Optional::NO,
                  "Block height to wait for."},
                 {"timeout", RPCArg::Type::NUM, /* default */ "0",
                  "Time in milliseconds to wait for a response. 0 "
                  "indicates no timeout."},
             },
             RPCResult{"{                           (json object)\n"
                       "  \"hash\" : {       (string) The blockhash\n"
                       "  \"height\" : {     (int) Block height\n"
                       "}\n"},
             RPCExamples{HelpExampleCli("waitforblockheight", "\"100\", 1000") +
                         HelpExampleRpc("waitforblockheight", "\"100\", 1000")},
         }
                                      .ToString());
     }
 
     int timeout = 0;
 
     int height = request.params[0].get_int();
 
     if (!request.params[1].isNull()) {
         timeout = request.params[1].get_int();
     }
 
     CUpdatedBlock block;
     {
         WAIT_LOCK(cs_blockchange, lock);
         if (timeout) {
             cond_blockchange.wait_for(
                 lock, std::chrono::milliseconds(timeout), [&height] {
                     return latestblock.height >= height || !IsRPCRunning();
                 });
         } else {
             cond_blockchange.wait(lock, [&height] {
                 return latestblock.height >= height || !IsRPCRunning();
             });
         }
         block = latestblock;
     }
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("hash", block.hash.GetHex());
     ret.pushKV("height", block.height);
     return ret;
 }
 
 static UniValue
 syncwithvalidationinterfacequeue(const Config &config,
                                  const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 0) {
         throw std::runtime_error(RPCHelpMan{
             "syncwithvalidationinterfacequeue",
             "\nWaits for the validation interface queue to catch up on "
             "everything that was there when we entered this function.\n",
             {},
             RPCResults{},
             RPCExamples{HelpExampleCli("syncwithvalidationinterfacequeue", "") +
                         HelpExampleRpc("syncwithvalidationinterfacequeue", "")},
         }
                                      .ToString());
     }
     SyncWithValidationInterfaceQueue();
     return NullUniValue;
 }
 
 static UniValue getdifficulty(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(RPCHelpMan{
             "getdifficulty",
             "\nReturns the proof-of-work difficulty as a multiple of the "
             "minimum difficulty.\n",
             {},
             RPCResult{"n.nnn       (numeric) the proof-of-work difficulty as a "
                       "multiple of the minimum difficulty.\n"},
             RPCExamples{HelpExampleCli("getdifficulty", "") +
                         HelpExampleRpc("getdifficulty", "")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
     return GetDifficulty(::ChainActive().Tip());
 }
 
 static std::string EntryDescriptionString() {
     return "    \"size\" : n,             (numeric) transaction size.\n"
            "    \"fee\" : n,              (numeric) transaction fee in " +
            CURRENCY_UNIT + "(DEPRECATED)" +
            "\n"
            "    \"modifiedfee\" : n,      (numeric) transaction fee with fee "
            "deltas used for mining priority (DEPRECATED)\n"
            "    \"time\" : n,             (numeric) local time transaction "
            "entered pool in seconds since 1 Jan 1970 GMT\n"
            "    \"height\" : n,           (numeric) block height when "
            "transaction entered pool\n"
            "    \"descendantcount\" : n,  (numeric) number of in-mempool "
            "descendant transactions (including this one)\n"
            "    \"descendantsize\" : n,   (numeric) transaction size "
            "of in-mempool descendants (including this one)\n"
            "    \"descendantfees\" : n,   (numeric) modified fees (see above) "
            "of in-mempool descendants (including this one) (DEPRECATED)\n"
            "    \"ancestorcount\" : n,    (numeric) number of in-mempool "
            "ancestor transactions (including this one)\n"
            "    \"ancestorsize\" : n,     (numeric) transaction size "
            "of in-mempool ancestors (including this one)\n"
            "    \"ancestorfees\" : n,     (numeric) modified fees (see above) "
            "of in-mempool ancestors (including this one) (DEPRECATED)\n"
            "    \"fees\" : {\n"
            "        \"base\" : n,         (numeric) transaction fee in " +
            CURRENCY_UNIT +
            "\n"
            "        \"modified\" : n,     (numeric) transaction fee with fee "
            "deltas used for mining priority in " +
            CURRENCY_UNIT +
            "\n"
            "        \"ancestor\" : n,     (numeric) modified fees (see above) "
            "of in-mempool ancestors (including this one) in " +
            CURRENCY_UNIT +
            "\n"
            "        \"descendant\" : n,   (numeric) modified fees (see above) "
            "of in-mempool descendants (including this one) in " +
            CURRENCY_UNIT +
            "\n"
            "    }\n"
            "    \"depends\" : [           (array) unconfirmed transactions "
            "used as inputs for this transaction\n"
            "        \"transactionid\",    (string) parent transaction id\n"
            "       ... ]\n"
            "    \"spentby\" : [           (array) unconfirmed transactions "
            "spending outputs from this transaction\n"
            "        \"transactionid\",    (string) child transaction id\n"
            "       ... ]\n";
 }
 
 static void entryToJSON(const CTxMemPool &pool, UniValue &info,
                         const CTxMemPoolEntry &e)
     EXCLUSIVE_LOCKS_REQUIRED(pool.cs) {
     AssertLockHeld(pool.cs);
 
     UniValue fees(UniValue::VOBJ);
     fees.pushKV("base", ValueFromAmount(e.GetFee()));
     fees.pushKV("modified", ValueFromAmount(e.GetModifiedFee()));
     fees.pushKV("ancestor", ValueFromAmount(e.GetModFeesWithAncestors()));
     fees.pushKV("descendant", ValueFromAmount(e.GetModFeesWithDescendants()));
     info.pushKV("fees", fees);
 
     info.pushKV("size", (int)e.GetTxSize());
     info.pushKV("fee", ValueFromAmount(e.GetFee()));
     info.pushKV("modifiedfee", ValueFromAmount(e.GetModifiedFee()));
     info.pushKV("time", e.GetTime());
     info.pushKV("height", (int)e.GetHeight());
     info.pushKV("descendantcount", e.GetCountWithDescendants());
     info.pushKV("descendantsize", e.GetSizeWithDescendants());
     info.pushKV("descendantfees", e.GetModFeesWithDescendants() / SATOSHI);
     info.pushKV("ancestorcount", e.GetCountWithAncestors());
     info.pushKV("ancestorsize", e.GetSizeWithAncestors());
     info.pushKV("ancestorfees", e.GetModFeesWithAncestors() / SATOSHI);
     const CTransaction &tx = e.GetTx();
     std::set<std::string> setDepends;
     for (const CTxIn &txin : tx.vin) {
         if (pool.exists(txin.prevout.GetTxId())) {
             setDepends.insert(txin.prevout.GetTxId().ToString());
         }
     }
 
     UniValue depends(UniValue::VARR);
     for (const std::string &dep : setDepends) {
         depends.push_back(dep);
     }
 
     info.pushKV("depends", depends);
 
     UniValue spent(UniValue::VARR);
     const CTxMemPool::txiter &it = pool.mapTx.find(tx.GetId());
     const CTxMemPool::setEntries &setChildren = pool.GetMemPoolChildren(it);
     for (CTxMemPool::txiter childiter : setChildren) {
         spent.push_back(childiter->GetTx().GetId().ToString());
     }
 
     info.pushKV("spentby", spent);
 }
 
 UniValue MempoolToJSON(const CTxMemPool &pool, bool verbose) {
     if (verbose) {
         LOCK(pool.cs);
         UniValue o(UniValue::VOBJ);
         for (const CTxMemPoolEntry &e : pool.mapTx) {
             const uint256 &txid = e.GetTx().GetId();
             UniValue info(UniValue::VOBJ);
             entryToJSON(pool, info, e);
             // Mempool has unique entries so there is no advantage in using
             // UniValue::pushKV, which checks if the key already exists in O(N).
             // UniValue::__pushKV is used instead which currently is O(1).
             o.__pushKV(txid.ToString(), info);
         }
         return o;
     } else {
         std::vector<uint256> vtxids;
         pool.queryHashes(vtxids);
 
         UniValue a(UniValue::VARR);
         for (const uint256 &txid : vtxids) {
             a.push_back(txid.ToString());
         }
 
         return a;
     }
 }
 
 static UniValue getrawmempool(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(RPCHelpMan{
             "getrawmempool",
             "\nReturns all transaction ids in memory pool as a json "
             "array of string transaction ids.\n"
             "\nHint: use getmempoolentry to fetch a specific "
             "transaction from the mempool.\n",
             {
                 {"verbose", RPCArg::Type::BOOL, /* default */ "false",
                  "True for a json object, false for array of "
                  "transaction ids"},
             },
             RPCResult{"for verbose = false",
                       "[                     (json array of string)\n"
                       "  \"transactionid\"     (string) The transaction id\n"
                       "  ,...\n"
                       "]\n"
                       "\nResult: (for verbose = true):\n"
                       "{                           (json object)\n"
                       "  \"transactionid\" : {       (json object)\n" +
                           EntryDescriptionString() +
                           "  }, ...\n"
                           "}\n"},
             RPCExamples{HelpExampleCli("getrawmempool", "true") +
                         HelpExampleRpc("getrawmempool", "true")},
         }
                                      .ToString());
     }
 
     bool fVerbose = false;
     if (!request.params[0].isNull()) {
         fVerbose = request.params[0].get_bool();
     }
 
     return MempoolToJSON(::g_mempool, fVerbose);
 }
 
 static UniValue getmempoolancestors(const Config &config,
                                     const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(RPCHelpMan{
             "getmempoolancestors",
             "\nIf txid is in the mempool, returns all in-mempool "
             "ancestors.\n",
             {
                 {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "The transaction id (must be in mempool)"},
                 {"verbose", RPCArg::Type::BOOL, /* default */ "false",
                  "True for a json object, false for array of "
                  "transaction ids"},
             },
             {
                 RPCResult{
                     "for verbose = false",
                     "[                       (json array of strings)\n"
                     "  \"transactionid\"           (string) The transaction id "
                     "of an in-mempool ancestor transaction\n"
                     "  ,...\n"
                     "]\n"},
                 RPCResult{"for verbose = true",
                           "{                           (json object)\n"
                           "  \"transactionid\" : {       (json object)\n" +
                               EntryDescriptionString() +
                               "  }, ...\n"
                               "}\n"},
             },
             RPCExamples{HelpExampleCli("getmempoolancestors", "\"mytxid\"") +
                         HelpExampleRpc("getmempoolancestors", "\"mytxid\"")},
         }
                                      .ToString());
     }
 
     bool fVerbose = false;
     if (!request.params[1].isNull()) {
         fVerbose = request.params[1].get_bool();
     }
 
     TxId txid(ParseHashV(request.params[0], "parameter 1"));
 
     LOCK(g_mempool.cs);
 
     CTxMemPool::txiter it = g_mempool.mapTx.find(txid);
     if (it == g_mempool.mapTx.end()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Transaction not in mempool");
     }
 
     CTxMemPool::setEntries setAncestors;
     uint64_t noLimit = std::numeric_limits<uint64_t>::max();
     std::string dummy;
     g_mempool.CalculateMemPoolAncestors(*it, setAncestors, noLimit, noLimit,
                                         noLimit, noLimit, dummy, false);
 
     if (!fVerbose) {
         UniValue o(UniValue::VARR);
         for (CTxMemPool::txiter ancestorIt : setAncestors) {
             o.push_back(ancestorIt->GetTx().GetId().ToString());
         }
 
         return o;
     } else {
         UniValue o(UniValue::VOBJ);
         for (CTxMemPool::txiter ancestorIt : setAncestors) {
             const CTxMemPoolEntry &e = *ancestorIt;
             const TxId &_txid = e.GetTx().GetId();
             UniValue info(UniValue::VOBJ);
             entryToJSON(::g_mempool, info, e);
             o.pushKV(_txid.ToString(), info);
         }
         return o;
     }
 }
 
 static UniValue getmempooldescendants(const Config &config,
                                       const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(RPCHelpMan{
             "getmempooldescendants",
             "\nIf txid is in the mempool, returns all in-mempool "
             "descendants.\n",
             {
                 {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "The transaction id (must be in mempool)"},
                 {"verbose", RPCArg::Type::BOOL, /* default */ "false",
                  "True for a json object, false for array of "
                  "transaction ids"},
             },
             {
                 RPCResult{
                     "for verbose = false",
                     "[                       (json array of strings)\n"
                     "  \"transactionid\"           (string) The transaction id "
                     "of an in-mempool descendant transaction\n"
                     "  ,...\n"
                     "]\n"},
                 RPCResult{"for verbose = true",
                           "{                           (json object)\n"
                           "  \"transactionid\" : {       (json object)\n" +
                               EntryDescriptionString() +
                               "  }, ...\n"
                               "}\n"},
             },
             RPCExamples{HelpExampleCli("getmempooldescendants", "\"mytxid\"") +
                         HelpExampleRpc("getmempooldescendants", "\"mytxid\"")},
         }
                                      .ToString());
     }
 
     bool fVerbose = false;
     if (!request.params[1].isNull()) {
         fVerbose = request.params[1].get_bool();
     }
 
     TxId txid(ParseHashV(request.params[0], "parameter 1"));
 
     LOCK(g_mempool.cs);
 
     CTxMemPool::txiter it = g_mempool.mapTx.find(txid);
     if (it == g_mempool.mapTx.end()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Transaction not in mempool");
     }
 
     CTxMemPool::setEntries setDescendants;
     g_mempool.CalculateDescendants(it, setDescendants);
     // CTxMemPool::CalculateDescendants will include the given tx
     setDescendants.erase(it);
 
     if (!fVerbose) {
         UniValue o(UniValue::VARR);
         for (CTxMemPool::txiter descendantIt : setDescendants) {
             o.push_back(descendantIt->GetTx().GetId().ToString());
         }
 
         return o;
     } else {
         UniValue o(UniValue::VOBJ);
         for (CTxMemPool::txiter descendantIt : setDescendants) {
             const CTxMemPoolEntry &e = *descendantIt;
             const TxId &_txid = e.GetTx().GetId();
             UniValue info(UniValue::VOBJ);
             entryToJSON(::g_mempool, info, e);
             o.pushKV(_txid.ToString(), info);
         }
         return o;
     }
 }
 
 static UniValue getmempoolentry(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(RPCHelpMan{
             "getmempoolentry",
             "\nReturns mempool data for given transaction\n",
             {
                 {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "The transaction id (must be in mempool)"},
             },
             RPCResult{"{                           (json object)\n" +
                       EntryDescriptionString() + "}\n"},
             RPCExamples{HelpExampleCli("getmempoolentry", "\"mytxid\"") +
                         HelpExampleRpc("getmempoolentry", "\"mytxid\"")},
         }
                                      .ToString());
     }
 
     TxId txid(ParseHashV(request.params[0], "parameter 1"));
 
     LOCK(g_mempool.cs);
 
     CTxMemPool::txiter it = g_mempool.mapTx.find(txid);
     if (it == g_mempool.mapTx.end()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Transaction not in mempool");
     }
 
     const CTxMemPoolEntry &e = *it;
     UniValue info(UniValue::VOBJ);
     entryToJSON(::g_mempool, info, e);
     return info;
 }
 
 static UniValue getblockhash(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(RPCHelpMan{
             "getblockhash",
             "\nReturns hash of block in best-block-chain at height "
             "provided.\n",
             {
                 {"height", RPCArg::Type::NUM, RPCArg::Optional::NO,
                  "The height index"},
             },
             RPCResult{"\"hash\"         (string) The block hash\n"},
             RPCExamples{HelpExampleCli("getblockhash", "1000") +
                         HelpExampleRpc("getblockhash", "1000")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
 
     int nHeight = request.params[0].get_int();
     if (nHeight < 0 || nHeight > ::ChainActive().Height()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Block height out of range");
     }
 
     CBlockIndex *pblockindex = ::ChainActive()[nHeight];
     return pblockindex->GetBlockHash().GetHex();
 }
 
 static UniValue getblockheader(const Config &config,
                                const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(RPCHelpMan{
             "getblockheader",
             "\nIf verbose is false, returns a string that is "
             "serialized, hex-encoded data for blockheader 'hash'.\n"
             "If verbose is true, returns an Object with information "
             "about blockheader <hash>.\n",
             {
                 {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "The block hash"},
                 {"verbose", RPCArg::Type::BOOL, /* default */ "true",
                  "true for a json object, false for the hex-encoded data"},
             },
             {
                 RPCResult{
                     "for verbose = true",
                     "{\n"
                     "  \"hash\" : \"hash\",     (string) the block hash (same "
                     "as provided)\n"
                     "  \"confirmations\" : n,   (numeric) The number of "
                     "confirmations, or -1 if the block is not on the main "
                     "chain\n"
                     "  \"height\" : n,          (numeric) The block height or "
                     "index\n"
                     "  \"version\" : n,         (numeric) The block version\n"
                     "  \"versionHex\" : \"00000000\", (string) The block "
                     "version formatted in hexadecimal\n"
                     "  \"merkleroot\" : \"xxxx\", (string) The merkle root\n"
                     "  \"time\" : ttt,          (numeric) The block time in "
                     "seconds since epoch (Jan 1 1970 GMT)\n"
                     "  \"mediantime\" : ttt,    (numeric) The median block "
                     "time in seconds since epoch (Jan 1 1970 GMT)\n"
                     "  \"nonce\" : n,           (numeric) The nonce\n"
                     "  \"bits\" : \"1d00ffff\", (string) The bits\n"
                     "  \"difficulty\" : x.xxx,  (numeric) The difficulty\n"
                     "  \"chainwork\" : \"0000...1f3\"     (string) Expected "
                     "number of hashes required to produce the current chain "
                     "(in hex)\n"
                     "  \"nTx\" : n,             (numeric) The number of "
                     "transactions in the block.\n"
                     "  \"previousblockhash\" : \"hash\",  (string) The hash of "
                     "the previous block\n"
                     "  \"nextblockhash\" : \"hash\",      (string) The hash of "
                     "the next block\n"
                     "}\n"},
                 RPCResult{"for verbose=false",
                           "\"data\"             (string) A string that is "
                           "serialized, hex-encoded data for block 'hash'.\n"},
             },
             RPCExamples{HelpExampleCli("getblockheader",
                                        "\"00000000c937983704a73af28acdec3"
                                        "7b049d214adbda81d7e2a3dd146f6ed09"
                                        "\"") +
                         HelpExampleRpc("getblockheader",
                                        "\"00000000c937983704a73af28acdec3"
                                        "7b049d214adbda81d7e2a3dd146f6ed09"
                                        "\"")},
         }
                                      .ToString());
     }
 
     BlockHash hash(ParseHashV(request.params[0], "hash"));
 
     bool fVerbose = true;
     if (!request.params[1].isNull()) {
         fVerbose = request.params[1].get_bool();
     }
 
     const CBlockIndex *pblockindex;
     const CBlockIndex *tip;
     {
         LOCK(cs_main);
         pblockindex = LookupBlockIndex(hash);
         tip = ::ChainActive().Tip();
     }
 
     if (!pblockindex) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
     }
 
     if (!fVerbose) {
         CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION);
         ssBlock << pblockindex->GetBlockHeader();
         std::string strHex = HexStr(ssBlock.begin(), ssBlock.end());
         return strHex;
     }
 
     return blockheaderToJSON(tip, pblockindex);
 }
 
 static CBlock GetBlockChecked(const Config &config,
                               const CBlockIndex *pblockindex) {
     CBlock block;
     if (IsBlockPruned(pblockindex)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Block not available (pruned data)");
     }
 
     if (!ReadBlockFromDisk(block, pblockindex,
                            config.GetChainParams().GetConsensus())) {
         // Block not found on disk. This could be because we have the block
         // header in our index but don't have the block (for example if a
         // non-whitelisted node sends us an unrequested long chain of valid
         // blocks, we add the headers to our index, but don't accept the block).
         throw JSONRPCError(RPC_MISC_ERROR, "Block not found on disk");
     }
 
     return block;
 }
 
 static UniValue getblock(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(RPCHelpMan{
             "getblock",
             "\nIf verbosity is 0 or false, returns a string that is "
             "serialized, hex-encoded data for block 'hash'.\n"
             "If verbosity is 1 or true, returns an Object with information "
             "about block <hash>.\n"
             "If verbosity is 2, returns an Object with information about "
             "block <hash> and information about each transaction.\n",
             {
                 {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "The block hash"},
                 {"verbosity", RPCArg::Type::NUM, /* default */ "1",
                  "0 for hex-encoded data, 1 for a json object, and 2 for "
                  "json object with transaction data"},
             },
             {
                 RPCResult{
                     "for verbosity = 0",
                     "\"data\"                   (string) A string that is "
                     "serialized, hex-encoded data for block 'hash'.\n"},
                 RPCResult{
                     "for verbosity = 1",
                     "{\n"
                     "  \"hash\" : \"hash\",       (string) The block hash "
                     "(same as provided)\n"
                     "  \"confirmations\" : n,   (numeric) The number of "
                     "confirmations, or -1 if the block is not on the main "
                     "chain\n"
                     "  \"size\" : n,            (numeric) The block size\n"
                     "  \"height\" : n,          (numeric) The block height or "
                     "index\n"
                     "  \"version\" : n,         (numeric) The block version\n"
                     "  \"versionHex\" : \"00000000\", (string) The block "
                     "version formatted in hexadecimal\n"
                     "  \"merkleroot\" : \"xxxx\", (string) The merkle root\n"
                     "  \"tx\" : [               (array of string) The "
                     "transaction ids\n"
                     "     \"transactionid\"     (string) The transaction id\n"
                     "     ,...\n"
                     "  ],\n"
                     "  \"time\" : ttt,          (numeric) The block time in "
                     "seconds since epoch (Jan 1 1970 GMT)\n"
                     "  \"mediantime\" : ttt,    (numeric) The median block "
                     "time in seconds since epoch (Jan 1 1970 GMT)\n"
                     "  \"nonce\" : n,           (numeric) The nonce\n"
                     "  \"bits\" : \"1d00ffff\",   (string) The bits\n"
                     "  \"difficulty\" : x.xxx,  (numeric) The difficulty\n"
                     "  \"chainwork\" : \"xxxx\",  (string) Expected number of "
                     "hashes required to produce the chain up to this block (in "
                     "hex)\n"
                     "  \"nTx\" : n,             (numeric) The number of "
                     "transactions in the block.\n"
                     "  \"previousblockhash\" : \"hash\",  (string) The hash of "
                     "the previous block\n"
                     "  \"nextblockhash\" : \"hash\"       (string) The hash of "
                     "the next block\n"
                     "}\n"},
                 RPCResult{
                     "for verbosity = 2",
                     "{\n"
                     "  ...,                   Same output as verbosity = 1\n"
                     "  \"tx\" : [               (array of Objects) The "
                     "transactions in the format of the getrawtransaction RPC; "
                     "different from verbosity = 1 \"tx\" result\n"
                     "    ...\n"
                     "  ],\n"
                     "  ...                    Same output as verbosity = 1\n"
                     "}\n"},
             },
             RPCExamples{HelpExampleCli("getblock",
                                        "\"00000000c937983704a73af28acdec37b049d"
                                        "214adbda81d7e2a3dd146f6ed09\"") +
                         HelpExampleRpc("getblock",
                                        "\"00000000c937983704a73af28acdec37b049d"
                                        "214adbda81d7e2a3dd146f6ed09\"")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
 
     BlockHash hash(ParseHashV(request.params[0], "blockhash"));
 
     int verbosity = 1;
     if (!request.params[1].isNull()) {
         if (request.params[1].isNum()) {
             verbosity = request.params[1].get_int();
         } else {
             verbosity = request.params[1].get_bool() ? 1 : 0;
         }
     }
 
     const CBlockIndex *pblockindex = LookupBlockIndex(hash);
     if (!pblockindex) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
     }
 
     const CBlock block = GetBlockChecked(config, pblockindex);
 
     if (verbosity <= 0) {
         CDataStream ssBlock(SER_NETWORK,
                             PROTOCOL_VERSION | RPCSerializationFlags());
         ssBlock << block;
         std::string strHex = HexStr(ssBlock.begin(), ssBlock.end());
         return strHex;
     }
 
     return blockToJSON(block, ::ChainActive().Tip(), pblockindex,
                        verbosity >= 2);
 }
 
 static UniValue pruneblockchain(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(RPCHelpMan{
             "pruneblockchain",
             "",
             {
                 {"height", RPCArg::Type::NUM, RPCArg::Optional::NO,
                  "The block height to prune up to. May be set to a discrete "
                  "height, or a unix timestamp\n"
                  "                  to prune blocks whose block time is at "
                  "least 2 hours older than the provided timestamp."},
             },
             RPCResult{"n    (numeric) Height of the last block pruned.\n"},
             RPCExamples{HelpExampleCli("pruneblockchain", "1000") +
                         HelpExampleRpc("pruneblockchain", "1000")},
         }
                                      .ToString());
     }
 
     if (!fPruneMode) {
         throw JSONRPCError(
             RPC_MISC_ERROR,
             "Cannot prune blocks because node is not in prune mode.");
     }
 
     LOCK(cs_main);
 
     int heightParam = request.params[0].get_int();
     if (heightParam < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative block height.");
     }
 
     // Height value more than a billion is too high to be a block height, and
     // too low to be a block time (corresponds to timestamp from Sep 2001).
     if (heightParam > 1000000000) {
         // Add a 2 hour buffer to include blocks which might have had old
         // timestamps
-        CBlockIndex *pindex =
-            ::ChainActive().FindEarliestAtLeast(heightParam - TIMESTAMP_WINDOW);
+        CBlockIndex *pindex = ::ChainActive().FindEarliestAtLeast(
+            heightParam - TIMESTAMP_WINDOW, 0);
         if (!pindex) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Could not find block with at least the specified timestamp.");
         }
         heightParam = pindex->nHeight;
     }
 
     unsigned int height = (unsigned int)heightParam;
     unsigned int chainHeight = (unsigned int)::ChainActive().Height();
     if (chainHeight < config.GetChainParams().PruneAfterHeight()) {
         throw JSONRPCError(RPC_MISC_ERROR,
                            "Blockchain is too short for pruning.");
     } else if (height > chainHeight) {
         throw JSONRPCError(
             RPC_INVALID_PARAMETER,
             "Blockchain is shorter than the attempted prune height.");
     } else if (height > chainHeight - MIN_BLOCKS_TO_KEEP) {
         LogPrint(BCLog::RPC, "Attempt to prune blocks close to the tip. "
                              "Retaining the minimum number of blocks.\n");
         height = chainHeight - MIN_BLOCKS_TO_KEEP;
     }
 
     PruneBlockFilesManual(height);
     return uint64_t(height);
 }
 
 static UniValue gettxoutsetinfo(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(RPCHelpMan{
             "gettxoutsetinfo",
             "\nReturns statistics about the unspent transaction output set.\n"
             "Note this call may take some time.\n",
             {},
             RPCResult{
                 "{\n"
                 "  \"height\":n,     (numeric) The current block height "
                 "(index)\n"
                 "  \"bestblock\": \"hex\",   (string) the best block hash hex\n"
                 "  \"transactions\": n,      (numeric) The number of "
                 "transactions\n"
                 "  \"txouts\": n,            (numeric) The number of output "
                 "transactions\n"
                 "  \"bogosize\": n,          (numeric) A database-independent "
                 "metric for UTXO set size\n"
                 "  \"hash_serialized\": \"hash\",   (string) The serialized "
                 "hash\n"
                 "  \"disk_size\": n,         (numeric) The estimated size of "
                 "the chainstate on disk\n"
                 "  \"total_amount\": x.xxx          (numeric) The total "
                 "amount\n"
                 "}\n"},
             RPCExamples{HelpExampleCli("gettxoutsetinfo", "") +
                         HelpExampleRpc("gettxoutsetinfo", "")},
         }
                                      .ToString());
     }
 
     UniValue ret(UniValue::VOBJ);
 
     CCoinsStats stats;
     ::ChainstateActive().ForceFlushStateToDisk();
     if (GetUTXOStats(pcoinsdbview.get(), stats)) {
         ret.pushKV("height", int64_t(stats.nHeight));
         ret.pushKV("bestblock", stats.hashBlock.GetHex());
         ret.pushKV("transactions", int64_t(stats.nTransactions));
         ret.pushKV("txouts", int64_t(stats.nTransactionOutputs));
         ret.pushKV("bogosize", int64_t(stats.nBogoSize));
         ret.pushKV("hash_serialized", stats.hashSerialized.GetHex());
         ret.pushKV("disk_size", stats.nDiskSize);
         ret.pushKV("total_amount", ValueFromAmount(stats.nTotalAmount));
     } else {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Unable to read UTXO set");
     }
     return ret;
 }
 
 UniValue gettxout(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 3) {
         throw std::runtime_error(RPCHelpMan{
             "gettxout",
             "\nReturns details about an unspent transaction output.\n",
             {
                 {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "The transaction id"},
                 {"n", RPCArg::Type::NUM, RPCArg::Optional::NO, "vout number"},
                 {"include_mempool", RPCArg::Type::BOOL, /* default */ "true",
                  "Whether to include the mempool. Note that an unspent "
                  "output that is spent in the mempool won't appear."},
             },
             RPCResult{
                 "{\n"
                 "  \"bestblock\" : \"hash\",    (string) the block hash\n"
                 "  \"confirmations\" : n,       (numeric) The number of "
                 "confirmations\n"
                 "  \"value\" : x.xxx,           (numeric) The transaction "
                 "value in " +
                 CURRENCY_UNIT +
                 "\n"
                 "  \"scriptPubKey\" : {         (json object)\n"
                 "     \"asm\" : \"code\",       (string) \n"
                 "     \"hex\" : \"hex\",        (string) \n"
                 "     \"reqSigs\" : n,          (numeric) Number of required "
                 "signatures\n"
                 "     \"type\" : \"pubkeyhash\", (string) The type, eg "
                 "pubkeyhash\n"
                 "     \"addresses\" : [          (array of string) array of "
                 "bitcoin addresses\n"
                 "        \"address\"     (string) bitcoin address\n"
                 "        ,...\n"
                 "     ]\n"
                 "  },\n"
                 "  \"coinbase\" : true|false   (boolean) Coinbase or not\n"
                 "}\n"},
             RPCExamples{"\nGet unspent transactions\n" +
                         HelpExampleCli("listunspent", "") +
                         "\nView the details\n" +
                         HelpExampleCli("gettxout", "\"txid\" 1") +
                         "\nAs a JSON-RPC call\n" +
                         HelpExampleRpc("gettxout", "\"txid\", 1")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
 
     UniValue ret(UniValue::VOBJ);
 
     TxId txid(ParseHashV(request.params[0], "txid"));
     int n = request.params[1].get_int();
     COutPoint out(txid, n);
     bool fMempool = true;
     if (!request.params[2].isNull()) {
         fMempool = request.params[2].get_bool();
     }
 
     Coin coin;
     if (fMempool) {
         LOCK(g_mempool.cs);
         CCoinsViewMemPool view(pcoinsTip.get(), g_mempool);
         if (!view.GetCoin(out, coin) || g_mempool.isSpent(out)) {
             return NullUniValue;
         }
     } else {
         if (!pcoinsTip->GetCoin(out, coin)) {
             return NullUniValue;
         }
     }
 
     const CBlockIndex *pindex = LookupBlockIndex(pcoinsTip->GetBestBlock());
     ret.pushKV("bestblock", pindex->GetBlockHash().GetHex());
     if (coin.GetHeight() == MEMPOOL_HEIGHT) {
         ret.pushKV("confirmations", 0);
     } else {
         ret.pushKV("confirmations",
                    int64_t(pindex->nHeight - coin.GetHeight() + 1));
     }
     ret.pushKV("value", ValueFromAmount(coin.GetTxOut().nValue));
     UniValue o(UniValue::VOBJ);
     ScriptPubKeyToUniv(coin.GetTxOut().scriptPubKey, o, true);
     ret.pushKV("scriptPubKey", o);
     ret.pushKV("coinbase", coin.IsCoinBase());
 
     return ret;
 }
 
 static UniValue verifychain(const Config &config,
                             const JSONRPCRequest &request) {
     int nCheckLevel = gArgs.GetArg("-checklevel", DEFAULT_CHECKLEVEL);
     int nCheckDepth = gArgs.GetArg("-checkblocks", DEFAULT_CHECKBLOCKS);
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(RPCHelpMan{
             "verifychain",
             "\nVerifies blockchain database.\n",
             {
                 {"checklevel", RPCArg::Type::NUM,
                  /* default */ strprintf("%d, range=0-4", nCheckLevel),
                  "How thorough the block verification is."},
                 {"nblocks", RPCArg::Type::NUM,
                  /* default */ strprintf("%d, 0=all", nCheckDepth),
                  "The number of blocks to check."},
             },
             RPCResult{"true|false       (boolean) Verified or not\n"},
             RPCExamples{HelpExampleCli("verifychain", "") +
                         HelpExampleRpc("verifychain", "")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
 
     if (!request.params[0].isNull()) {
         nCheckLevel = request.params[0].get_int();
     }
     if (!request.params[1].isNull()) {
         nCheckDepth = request.params[1].get_int();
     }
 
     return CVerifyDB().VerifyDB(config, pcoinsTip.get(), nCheckLevel,
                                 nCheckDepth);
 }
 
 static void BIP9SoftForkDescPushBack(UniValue &softforks,
                                      const Consensus::Params &consensusParams,
                                      Consensus::DeploymentPos id)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     // For BIP9 deployments.
     // Deployments (e.g. testdummy) with timeout value before Jan 1, 2009 are
     // hidden. A timeout value of 0 guarantees a softfork will never be
     // activated. This is used when merging logic to implement a proposed
     // softfork without a specified deployment schedule.
     if (consensusParams.vDeployments[id].nTimeout <= 1230768000) {
         return;
     }
 
     UniValue bip9(UniValue::VOBJ);
     const ThresholdState thresholdState =
         VersionBitsTipState(consensusParams, id);
     switch (thresholdState) {
         case ThresholdState::DEFINED:
             bip9.pushKV("status", "defined");
             break;
         case ThresholdState::STARTED:
             bip9.pushKV("status", "started");
             break;
         case ThresholdState::LOCKED_IN:
             bip9.pushKV("status", "locked_in");
             break;
         case ThresholdState::ACTIVE:
             bip9.pushKV("status", "active");
             break;
         case ThresholdState::FAILED:
             bip9.pushKV("status", "failed");
             break;
     }
     if (ThresholdState::STARTED == thresholdState) {
         bip9.pushKV("bit", consensusParams.vDeployments[id].bit);
     }
     bip9.pushKV("start_time", consensusParams.vDeployments[id].nStartTime);
     bip9.pushKV("timeout", consensusParams.vDeployments[id].nTimeout);
     int64_t since_height = VersionBitsTipStateSinceHeight(consensusParams, id);
     bip9.pushKV("since", since_height);
     if (ThresholdState::STARTED == thresholdState) {
         UniValue statsUV(UniValue::VOBJ);
         BIP9Stats statsStruct = VersionBitsTipStatistics(consensusParams, id);
         statsUV.pushKV("period", statsStruct.period);
         statsUV.pushKV("threshold", statsStruct.threshold);
         statsUV.pushKV("elapsed", statsStruct.elapsed);
         statsUV.pushKV("count", statsStruct.count);
         statsUV.pushKV("possible", statsStruct.possible);
         bip9.pushKV("statistics", statsUV);
     }
 
     UniValue rv(UniValue::VOBJ);
     rv.pushKV("type", "bip9");
     rv.pushKV("bip9", bip9);
     if (ThresholdState::ACTIVE == thresholdState) {
         rv.pushKV("height", since_height);
     }
     rv.pushKV("active", ThresholdState::ACTIVE == thresholdState);
 
     softforks.pushKV(VersionBitsDeploymentInfo[id].name, rv);
 }
 
 UniValue getblockchaininfo(const Config &config,
                            const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(RPCHelpMan{
             "getblockchaininfo",
             "Returns an object containing various state info "
             "regarding blockchain processing.\n",
             {},
             RPCResult{
                 "{\n"
                 "  \"chain\": \"xxxx\",              (string) current network "
                 "name as defined in BIP70 (main, test, regtest)\n"
                 "  \"blocks\": xxxxxx,             (numeric) the current "
                 "number of blocks processed in the server\n"
                 "  \"headers\": xxxxxx,            (numeric) the current "
                 "number of headers we have validated\n"
                 "  \"bestblockhash\": \"...\",       (string) the hash of the "
                 "currently best block\n"
                 "  \"difficulty\": xxxxxx,         (numeric) the current "
                 "difficulty\n"
                 "  \"mediantime\": xxxxxx,         (numeric) median time for "
                 "the current best block\n"
                 "  \"verificationprogress\": xxxx, (numeric) estimate of "
                 "verification progress [0..1]\n"
                 "  \"initialblockdownload\": xxxx, (bool) (debug information) "
                 "estimate of whether this node is in Initial Block Download "
                 "mode.\n"
                 "  \"chainwork\": \"xxxx\"           (string) total amount of "
                 "work in active chain, in hexadecimal\n"
                 "  \"size_on_disk\": xxxxxx,       (numeric) the estimated "
                 "size of the block and undo files on disk\n"
                 "  \"pruned\": xx,                 (boolean) if the blocks are "
                 "subject to pruning\n"
                 "  \"pruneheight\": xxxxxx,        (numeric) lowest-height "
                 "complete block stored (only present if pruning is enabled)\n"
                 "  \"automatic_pruning\": xx,      (boolean) whether automatic "
                 "pruning is enabled (only present if pruning is enabled)\n"
                 "  \"prune_target_size\": xxxxxx,  (numeric) the target size "
                 "used by pruning (only present if automatic pruning is "
                 "enabled)\n"
                 "  \"softforks\": {                (object) status of "
                 "softforks in progress\n"
                 "    \"xxxx\" : {                  (string) name of the "
                 "softfork\n"
                 "      \"type\" : \"bip9\",        (string) currently only set "
                 "to \"bip9\"\n"
                 "      \"bip9\" : {                (object) status of bip9 "
                 "softforks (only for \"bip9\" type)\n"
                 "        \"status\": \"xxxx\",     (string) one of "
                 "\"defined\", \"started\", \"locked_in\", \"active\", "
                 "\"failed\"\n"
                 "        \"bit\": xx,              (numeric) the bit (0-28) in "
                 "the block version field used to signal this softfork (only "
                 "for \"started\" status)\n"
                 "        \"startTime\": xx,        (numeric) the minimum "
                 "median time past of a block at which the bit gains its "
                 "meaning\n"
                 "        \"timeout\": xx,          (numeric) the median time "
                 "past of a block at which the deployment is considered failed "
                 "if not "
                 "yet locked in\n"
                 "        \"since\": xx,            (numeric) height of the "
                 "first block to which the status applies\n"
                 "        \"statistics\": {         (object) numeric statistics "
                 "about BIP9 signalling for a softfork (only for \"started\" "
                 "status)\n"
                 "          \"period\": xx,         (numeric) the length in "
                 "blocks of the BIP9 signalling period \n"
                 "          \"threshold\": xx,      (numeric) the number of "
                 "blocks with the version bit set required to activate the "
                 "feature \n"
                 "          \"elapsed\": xx,        (numeric) the number of "
                 "blocks elapsed since the beginning of the current period \n"
                 "          \"count\": xx,          (numeric) the number of "
                 "blocks with the version bit set in the current period \n"
                 "          \"possible\": xx        (boolean) returns false if "
                 "there are not enough blocks left in this period to pass "
                 "activation threshold\n"
                 "        },\n"
                 "        \"active\": xx,           (boolean) true if the rules "
                 "are enforced for the mempool and the next block\n"
                 "      }\n"
                 "    }\n"
                 "  }\n"
                 "  \"warnings\" : \"...\",           (string) any network and "
                 "blockchain warnings.\n"
                 "}\n"},
             RPCExamples{HelpExampleCli("getblockchaininfo", "") +
                         HelpExampleRpc("getblockchaininfo", "")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
 
     const CChainParams &chainparams = config.GetChainParams();
 
     const CBlockIndex *tip = ::ChainActive().Tip();
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("chain", chainparams.NetworkIDString());
     obj.pushKV("blocks", int(::ChainActive().Height()));
     obj.pushKV("headers", pindexBestHeader ? pindexBestHeader->nHeight : -1);
     obj.pushKV("bestblockhash", tip->GetBlockHash().GetHex());
     obj.pushKV("difficulty", double(GetDifficulty(tip)));
     obj.pushKV("mediantime", int64_t(tip->GetMedianTimePast()));
     obj.pushKV("verificationprogress",
                GuessVerificationProgress(Params().TxData(), tip));
     obj.pushKV("initialblockdownload",
                ::ChainstateActive().IsInitialBlockDownload());
     obj.pushKV("chainwork", tip->nChainWork.GetHex());
     obj.pushKV("size_on_disk", CalculateCurrentUsage());
     obj.pushKV("pruned", fPruneMode);
 
     if (fPruneMode) {
         const CBlockIndex *block = tip;
         assert(block);
         while (block->pprev && (block->pprev->nStatus.hasData())) {
             block = block->pprev;
         }
 
         obj.pushKV("pruneheight", block->nHeight);
 
         // if 0, execution bypasses the whole if block.
         bool automatic_pruning = (gArgs.GetArg("-prune", 0) != 1);
         obj.pushKV("automatic_pruning", automatic_pruning);
         if (automatic_pruning) {
             obj.pushKV("prune_target_size", nPruneTarget);
         }
     }
 
     UniValue softforks(UniValue::VOBJ);
     for (int i = 0; i < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; i++) {
         BIP9SoftForkDescPushBack(softforks, chainparams.GetConsensus(),
                                  Consensus::DeploymentPos(i));
     }
     obj.pushKV("softforks", softforks);
 
     obj.pushKV("warnings", GetWarnings("statusbar"));
     return obj;
 }
 
 /** Comparison function for sorting the getchaintips heads.  */
 struct CompareBlocksByHeight {
     bool operator()(const CBlockIndex *a, const CBlockIndex *b) const {
         // Make sure that unequal blocks with the same height do not compare
         // equal. Use the pointers themselves to make a distinction.
         if (a->nHeight != b->nHeight) {
             return (a->nHeight > b->nHeight);
         }
 
         return a < b;
     }
 };
 
 static UniValue getchaintips(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(RPCHelpMan{
             "getchaintips",
             "Return information about all known tips in the block tree, "
             "including the main chain as well as orphaned branches.\n",
             {},
             RPCResult{
                 "[\n"
                 "  {\n"
                 "    \"height\": xxxx,         (numeric) height of the chain "
                 "tip\n"
                 "    \"hash\": \"xxxx\",         (string) block hash of the "
                 "tip\n"
                 "    \"branchlen\": 0          (numeric) zero for main chain\n"
                 "    \"status\": \"active\"      (string) \"active\" for the "
                 "main chain\n"
                 "  },\n"
                 "  {\n"
                 "    \"height\": xxxx,\n"
                 "    \"hash\": \"xxxx\",\n"
                 "    \"branchlen\": 1          (numeric) length of branch "
                 "connecting the tip to the main chain\n"
                 "    \"status\": \"xxxx\"        (string) status of the chain "
                 "(active, valid-fork, valid-headers, headers-only, invalid)\n"
                 "  }\n"
                 "]\n"
                 "Possible values for status:\n"
                 "1.  \"invalid\"               This branch contains at least "
                 "one invalid block\n"
                 "2.  \"parked\"                This branch contains at least "
                 "one parked block\n"
                 "3.  \"headers-only\"          Not all blocks for this branch "
                 "are available, but the headers are valid\n"
                 "4.  \"valid-headers\"         All blocks are available for "
                 "this branch, but they were never fully validated\n"
                 "5.  \"valid-fork\"            This branch is not part of the "
                 "active chain, but is fully validated\n"
                 "6.  \"active\"                This is the tip of the active "
                 "main chain, which is certainly valid\n"},
             RPCExamples{HelpExampleCli("getchaintips", "") +
                         HelpExampleRpc("getchaintips", "")},
         }
                                      .ToString());
     }
 
     LOCK(cs_main);
 
     /**
      * Idea:  the set of chain tips is ::ChainActive().tip, plus orphan blocks
      * which do not have another orphan building off of them. Algorithm:
      *  - Make one pass through mapBlockIndex, picking out the orphan blocks,
      * and also storing a set of the orphan block's pprev pointers.
      *  - Iterate through the orphan blocks. If the block isn't pointed to by
      * another orphan, it is a chain tip.
      *  - add ::ChainActive().Tip()
      */
     std::set<const CBlockIndex *, CompareBlocksByHeight> setTips;
     std::set<const CBlockIndex *> setOrphans;
     std::set<const CBlockIndex *> setPrevs;
 
     for (const std::pair<const BlockHash, CBlockIndex *> &item :
          mapBlockIndex) {
         if (!::ChainActive().Contains(item.second)) {
             setOrphans.insert(item.second);
             setPrevs.insert(item.second->pprev);
         }
     }
 
     for (std::set<const CBlockIndex *>::iterator it = setOrphans.begin();
          it != setOrphans.end(); ++it) {
         if (setPrevs.erase(*it) == 0) {
             setTips.insert(*it);
         }
     }
 
     // Always report the currently active tip.
     setTips.insert(::ChainActive().Tip());
 
     /* Construct the output array.  */
     UniValue res(UniValue::VARR);
     for (const CBlockIndex *block : setTips) {
         UniValue obj(UniValue::VOBJ);
         obj.pushKV("height", block->nHeight);
         obj.pushKV("hash", block->phashBlock->GetHex());
 
         const int branchLen =
             block->nHeight - ::ChainActive().FindFork(block)->nHeight;
         obj.pushKV("branchlen", branchLen);
 
         std::string status;
         if (::ChainActive().Contains(block)) {
             // This block is part of the currently active chain.
             status = "active";
         } else if (block->nStatus.isInvalid()) {
             // This block or one of its ancestors is invalid.
             status = "invalid";
         } else if (block->nStatus.isOnParkedChain()) {
             // This block or one of its ancestors is parked.
             status = "parked";
         } else if (!block->HaveTxsDownloaded()) {
             // This block cannot be connected because full block data for it or
             // one of its parents is missing.
             status = "headers-only";
         } else if (block->IsValid(BlockValidity::SCRIPTS)) {
             // This block is fully validated, but no longer part of the active
             // chain. It was probably the active block once, but was
             // reorganized.
             status = "valid-fork";
         } else if (block->IsValid(BlockValidity::TREE)) {
             // The headers for this block are valid, but it has not been
             // validated. It was probably never part of the most-work chain.
             status = "valid-headers";
         } else {
             // No clue.
             status = "unknown";
         }
         obj.pushKV("status", status);
 
         res.push_back(obj);
     }
 
     return res;
 }
 
 UniValue MempoolInfoToJSON(const CTxMemPool &pool) {
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("loaded", pool.IsLoaded());
     ret.pushKV("size", (int64_t)pool.size());
     ret.pushKV("bytes", (int64_t)pool.GetTotalTxSize());
     ret.pushKV("usage", (int64_t)pool.DynamicMemoryUsage());
     size_t maxmempool =
         gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
     ret.pushKV("maxmempool", (int64_t)maxmempool);
     ret.pushKV(
         "mempoolminfee",
         ValueFromAmount(std::max(pool.GetMinFee(maxmempool), ::minRelayTxFee)
                             .GetFeePerK()));
     ret.pushKV("minrelaytxfee", ValueFromAmount(::minRelayTxFee.GetFeePerK()));
 
     return ret;
 }
 
 static UniValue getmempoolinfo(const Config &config,
                                const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(RPCHelpMan{
             "getmempoolinfo",
             "\nReturns details on the active state of the TX memory "
             "pool.\n",
             {},
             RPCResult{
                 "{\n"
                 "  \"loaded\": true|false         (boolean) True if the "
                 "mempool is fully loaded\n"
                 "  \"size\": xxxxx,               (numeric) Current tx count\n"
                 "  \"bytes\": xxxxx,              (numeric) Transaction size.\n"
                 "  \"usage\": xxxxx,              (numeric) Total memory usage "
                 "for the mempool\n"
                 "  \"maxmempool\": xxxxx,         (numeric) Maximum memory "
                 "usage for the mempool\n"
                 "  \"mempoolminfee\": xxxxx       (numeric) Minimum fee rate "
                 "in " +
                 CURRENCY_UNIT +
                 "/kB for tx to be accepted. Is the maximum of minrelaytxfee "
                 "and minimum mempool fee\n"
                 "  \"minrelaytxfee\": xxxxx       (numeric) Current minimum "
                 "relay fee for transactions\n"
                 "}\n"},
             RPCExamples{HelpExampleCli("getmempoolinfo", "") +
                         HelpExampleRpc("getmempoolinfo", "")},
         }
                                      .ToString());
     }
 
     return MempoolInfoToJSON(::g_mempool);
 }
 
 static UniValue preciousblock(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(RPCHelpMan{
             "preciousblock",
             "\nTreats a block as if it were received before others "
             "with the same work.\n"
             "\nA later preciousblock call can override the effect "
             "of an earlier one.\n"
             "\nThe effects of preciousblock are not retained across "
             "restarts.\n",
             {
                 {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "the hash of the block to mark as precious"},
             },
             RPCResults{},
             RPCExamples{HelpExampleCli("preciousblock", "\"blockhash\"") +
                         HelpExampleRpc("preciousblock", "\"blockhash\"")},
         }
                                      .ToString());
     }
 
     BlockHash hash(ParseHashV(request.params[0], "blockhash"));
     CBlockIndex *pblockindex;
 
     {
         LOCK(cs_main);
         pblockindex = LookupBlockIndex(hash);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
     }
 
     CValidationState state;
     PreciousBlock(config, state, pblockindex);
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, state.GetRejectReason());
     }
 
     return NullUniValue;
 }
 
 UniValue finalizeblock(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(RPCHelpMan{
             "finalizeblock",
             "\nTreats a block as final. It cannot be reorged. Any chain\n"
             "that does not contain this block is invalid. Used on a less\n"
             "work chain, it can effectively PUTS YOU OUT OF CONSENSUS.\n"
             "USE WITH CAUTION!\n",
             {
                 {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "the hash of the block to mark as invalid"},
             },
             RPCResults{},
             RPCExamples{HelpExampleCli("invalidateblock", "\"blockhash\"") +
                         HelpExampleRpc("invalidateblock", "\"blockhash\"")},
         }
                                      .ToString());
     }
 
     std::string strHash = request.params[0].get_str();
     BlockHash hash(uint256S(strHash));
     CValidationState state;
 
     {
         LOCK(cs_main);
         CBlockIndex *pblockindex = LookupBlockIndex(hash);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
 
         FinalizeBlockAndInvalidate(config, state, pblockindex);
     }
 
     if (state.IsValid()) {
         ActivateBestChain(config, state);
     }
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, FormatStateMessage(state));
     }
 
     return NullUniValue;
 }
 
 static UniValue invalidateblock(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(RPCHelpMan{
             "invalidateblock",
             "\nPermanently marks a block as invalid, as if it "
             "violated a consensus rule.\n",
             {
                 {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "the hash of the block to mark as invalid"},
             },
             RPCResults{},
             RPCExamples{HelpExampleCli("invalidateblock", "\"blockhash\"") +
                         HelpExampleRpc("invalidateblock", "\"blockhash\"")},
         }
                                      .ToString());
     }
 
     const BlockHash hash(ParseHashV(request.params[0], "blockhash"));
     CValidationState state;
 
     CBlockIndex *pblockindex;
     {
         LOCK(cs_main);
         pblockindex = LookupBlockIndex(hash);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
     }
     InvalidateBlock(config, state, pblockindex);
 
     if (state.IsValid()) {
         ActivateBestChain(config, state);
     }
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, FormatStateMessage(state));
     }
 
     return NullUniValue;
 }
 
 UniValue parkblock(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(RPCHelpMan{
             "parkblock",
             "\nMarks a block as parked.\n",
             {
                 {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "the hash of the block to park"},
             },
             RPCResults{},
             RPCExamples{HelpExampleCli("parkblock", "\"blockhash\"") +
                         HelpExampleRpc("parkblock", "\"blockhash\"")},
         }
                                      .ToString());
     }
 
     const std::string strHash = request.params[0].get_str();
     const BlockHash hash(uint256S(strHash));
     CValidationState state;
 
     CBlockIndex *pblockindex;
     {
         LOCK(cs_main);
         if (mapBlockIndex.count(hash) == 0) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
 
         pblockindex = mapBlockIndex[hash];
     }
     ParkBlock(config, state, pblockindex);
 
     if (state.IsValid()) {
         ActivateBestChain(config, state);
     }
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, state.GetRejectReason());
     }
 
     return NullUniValue;
 }
 
 static UniValue reconsiderblock(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(RPCHelpMan{
             "reconsiderblock",
             "\nRemoves invalidity status of a block and its descendants, "
             "reconsider them for activation.\n"
             "This can be used to undo the effects of invalidateblock.\n",
             {
                 {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "the hash of the block to reconsider"},
             },
             RPCResults{},
             RPCExamples{HelpExampleCli("reconsiderblock", "\"blockhash\"") +
                         HelpExampleRpc("reconsiderblock", "\"blockhash\"")},
         }
                                      .ToString());
     }
 
     const BlockHash hash(ParseHashV(request.params[0], "blockhash"));
 
     {
         LOCK(cs_main);
         CBlockIndex *pblockindex = LookupBlockIndex(hash);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
 
         ResetBlockFailureFlags(pblockindex);
     }
 
     CValidationState state;
     ActivateBestChain(config, state);
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, FormatStateMessage(state));
     }
 
     return NullUniValue;
 }
 
 UniValue unparkblock(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(RPCHelpMan{
             "unparkblock",
             "\nRemoves parked status of a block and its descendants, "
             "reconsider them for activation.\n"
             "This can be used to undo the effects of parkblock.\n",
             {
                 {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
                  "the hash of the block to unpark"},
             },
             RPCResults{},
             RPCExamples{HelpExampleCli("unparkblock", "\"blockhash\"") +
                         HelpExampleRpc("unparkblock", "\"blockhash\"")},
         }
                                      .ToString());
     }
 
     const std::string strHash = request.params[0].get_str();
     const BlockHash hash(uint256S(strHash));
 
     {
         LOCK(cs_main);
         if (mapBlockIndex.count(hash) == 0) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
 
         CBlockIndex *pblockindex = mapBlockIndex[hash];
         UnparkBlockAndChildren(pblockindex);
     }
 
     CValidationState state;
     ActivateBestChain(config, state);
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, state.GetRejectReason());
     }
 
     return NullUniValue;
 }
 
 static UniValue getchaintxstats(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(RPCHelpMan{
             "getchaintxstats",
             "\nCompute statistics about the total number and rate "
             "of transactions in the chain.\n",
             {
                 {"nblocks", RPCArg::Type::NUM, /* default */ "one month",
                  "Size of the window in number of blocks"},
                 {"blockhash", RPCArg::Type::STR_HEX, /* default */ "chain tip",
                  "The hash of the block that ends the window."},
             },
             RPCResult{
                 "{\n"
                 "  \"time\": xxxxx,                         (numeric) The "
                 "timestamp for the final block in the window in UNIX format.\n"
                 "  \"txcount\": xxxxx,                      (numeric) The "
                 "total number of transactions in the chain up to that point.\n"
                 "  \"window_final_block_hash\": \"...\",      (string) The "
                 "hash of the final block in the window.\n"
                 "  \"window_block_count\": xxxxx,           (numeric) Size of "
                 "the window in number of blocks.\n"
                 "  \"window_tx_count\": xxxxx,              (numeric) The "
                 "number of transactions in the window. Only returned if "
                 "\"window_block_count\" is > 0.\n"
                 "  \"window_interval\": xxxxx,              (numeric) The "
                 "elapsed time in the window in seconds. Only returned if "
                 "\"window_block_count\" is > 0.\n"
                 "  \"txrate\": x.xx,                        (numeric) The "
                 "average rate of transactions per second in the window. Only "
                 "returned if \"window_interval\" is > 0.\n"
                 "}\n"},
             RPCExamples{HelpExampleCli("getchaintxstats", "") +
                         HelpExampleRpc("getchaintxstats", "2016")},
         }
                                      .ToString());
     }
 
     const CBlockIndex *pindex;
 
     // By default: 1 month
     int blockcount = 30 * 24 * 60 * 60 /
                      config.GetChainParams().GetConsensus().nPowTargetSpacing;
 
     if (request.params[1].isNull()) {
         LOCK(cs_main);
         pindex = ::ChainActive().Tip();
     } else {
         BlockHash hash(ParseHashV(request.params[1], "blockhash"));
         LOCK(cs_main);
         pindex = LookupBlockIndex(hash);
         if (!pindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
         if (!::ChainActive().Contains(pindex)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Block is not in main chain");
         }
     }
 
     assert(pindex != nullptr);
 
     if (request.params[0].isNull()) {
         blockcount = std::max(0, std::min(blockcount, pindex->nHeight - 1));
     } else {
         blockcount = request.params[0].get_int();
 
         if (blockcount < 0 ||
             (blockcount > 0 && blockcount >= pindex->nHeight)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid block count: "
                                                       "should be between 0 and "
                                                       "the block's height - 1");
         }
     }
 
     const CBlockIndex *pindexPast =
         pindex->GetAncestor(pindex->nHeight - blockcount);
     int nTimeDiff =
         pindex->GetMedianTimePast() - pindexPast->GetMedianTimePast();
     int nTxDiff = pindex->nChainTx - pindexPast->nChainTx;
 
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("time", int64_t(pindex->nTime));
     ret.pushKV("txcount", int64_t(pindex->nChainTx));
     ret.pushKV("window_final_block_hash", pindex->GetBlockHash().GetHex());
     ret.pushKV("window_block_count", blockcount);
     if (blockcount > 0) {
         ret.pushKV("window_tx_count", nTxDiff);
         ret.pushKV("window_interval", nTimeDiff);
         if (nTimeDiff > 0) {
             ret.pushKV("txrate", double(nTxDiff) / nTimeDiff);
         }
     }
 
     return ret;
 }
 
 template <typename T>
 static T CalculateTruncatedMedian(std::vector<T> &scores) {
     size_t size = scores.size();
     if (size == 0) {
         return T();
     }
 
     std::sort(scores.begin(), scores.end());
     if (size % 2 == 0) {
         return (scores[size / 2 - 1] + scores[size / 2]) / 2;
     } else {
         return scores[size / 2];
     }
 }
 
 template <typename T> static inline bool SetHasKeys(const std::set<T> &set) {
     return false;
 }
 template <typename T, typename Tk, typename... Args>
 static inline bool SetHasKeys(const std::set<T> &set, const Tk &key,
                               const Args &... args) {
     return (set.count(key) != 0) || SetHasKeys(set, args...);
 }
 
 // outpoint (needed for the utxo index) + nHeight + fCoinBase
 static constexpr size_t PER_UTXO_OVERHEAD =
     sizeof(COutPoint) + sizeof(uint32_t) + sizeof(bool);
 
 static UniValue getblockstats(const Config &config,
                               const JSONRPCRequest &request) {
     const RPCHelpMan help{
         "getblockstats",
         "\nCompute per block statistics for a given window. All amounts are "
         "in " +
             CURRENCY_UNIT +
             ".\n"
             "It won't work for some heights with pruning.\n"
             "It won't work without -txindex for utxo_size_inc, *fee or "
             "*feerate stats.\n",
         {
             {"hash_or_height",
              RPCArg::Type::NUM,
              RPCArg::Optional::NO,
              "The block hash or height of the target block",
              "",
              {"", "string or numeric"}},
             {"stats",
              RPCArg::Type::ARR,
              /* default */ "all values",
              "Values to plot (see result below)",
              {
                  {"height", RPCArg::Type::STR, RPCArg::Optional::OMITTED,
                   "Selected statistic"},
                  {"time", RPCArg::Type::STR, RPCArg::Optional::OMITTED,
                   "Selected statistic"},
              },
              "stats"},
         },
         RPCResult{
             "{                           (json object)\n"
             "  \"avgfee\": x.xxx,          (numeric) Average fee in the block\n"
             "  \"avgfeerate\": x.xxx,      (numeric) Average feerate (in " +
             CURRENCY_UNIT +
             " per byte)\n"
             "  \"avgtxsize\": xxxxx,       (numeric) Average transaction size\n"
             "  \"blockhash\": xxxxx,       (string) The block hash (to check "
             "for potential reorgs)\n"
             "  \"height\": xxxxx,          (numeric) The height of the block\n"
             "  \"ins\": xxxxx,             (numeric) The number of inputs "
             "(excluding coinbase)\n"
             "  \"maxfee\": xxxxx,          (numeric) Maximum fee in the block\n"
             "  \"maxfeerate\": xxxxx,      (numeric) Maximum feerate (in " +
             CURRENCY_UNIT +
             " per byte)\n"
             "  \"maxtxsize\": xxxxx,       (numeric) Maximum transaction size\n"
             "  \"medianfee\": x.xxx,       (numeric) Truncated median fee in "
             "the block\n"
             "  \"medianfeerate\": x.xxx,   (numeric) Truncated median feerate "
             "(in " +
             CURRENCY_UNIT +
             " per byte)\n"
             "  \"mediantime\": xxxxx,      (numeric) The block median time "
             "past\n"
             "  \"mediantxsize\": xxxxx,    (numeric) Truncated median "
             "transaction size\n"
             "  \"minfee\": x.xxx,          (numeric) Minimum fee in the block\n"
             "  \"minfeerate\": xx.xx,      (numeric) Minimum feerate (in " +
             CURRENCY_UNIT +
             " per byte)\n"
             "  \"mintxsize\": xxxxx,       (numeric) Minimum transaction size\n"
             "  \"outs\": xxxxx,            (numeric) The number of outputs\n"
             "  \"subsidy\": x.xxx,         (numeric) The block subsidy\n"
             "  \"time\": xxxxx,            (numeric) The block time\n"
             "  \"total_out\": x.xxx,       (numeric) Total amount in all "
             "outputs (excluding coinbase and thus reward [ie subsidy + "
             "totalfee])\n"
             "  \"total_size\": xxxxx,      (numeric) Total size of all "
             "non-coinbase transactions\n"
             "  \"totalfee\": x.xxx,        (numeric) The fee total\n"
             "  \"txs\": xxxxx,             (numeric) The number of "
             "transactions (excluding coinbase)\n"
             "  \"utxo_increase\": xxxxx,   (numeric) The increase/decrease in "
             "the number of unspent outputs\n"
             "  \"utxo_size_inc\": xxxxx,   (numeric) The increase/decrease in "
             "size for the utxo index (not discounting op_return and similar)\n"
             "}\n"},
         RPCExamples{HelpExampleCli("getblockstats",
                                    "1000 '[\"minfeerate\",\"avgfeerate\"]'") +
                     HelpExampleRpc("getblockstats",
                                    "1000 '[\"minfeerate\",\"avgfeerate\"]'")},
     };
 
     if (request.fHelp || !help.IsValidNumArgs(request.params.size())) {
         throw std::runtime_error(help.ToString());
     }
 
     LOCK(cs_main);
 
     CBlockIndex *pindex;
     if (request.params[0].isNum()) {
         const int height = request.params[0].get_int();
         const int current_tip = ::ChainActive().Height();
         if (height < 0) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Target block height %d is negative", height));
         }
         if (height > current_tip) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Target block height %d after current tip %d", height,
                           current_tip));
         }
 
         pindex = ::ChainActive()[height];
     } else {
         const BlockHash hash(ParseHashV(request.params[0], "hash_or_height"));
         pindex = LookupBlockIndex(hash);
         if (!pindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
         if (!::ChainActive().Contains(pindex)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                strprintf("Block is not in chain %s",
                                          Params().NetworkIDString()));
         }
     }
 
     assert(pindex != nullptr);
 
     std::set<std::string> stats;
     if (!request.params[1].isNull()) {
         const UniValue stats_univalue = request.params[1].get_array();
         for (unsigned int i = 0; i < stats_univalue.size(); i++) {
             const std::string stat = stats_univalue[i].get_str();
             stats.insert(stat);
         }
     }
 
     const CBlock block = GetBlockChecked(config, pindex);
 
     // Calculate everything if nothing selected (default)
     const bool do_all = stats.size() == 0;
     const bool do_mediantxsize = do_all || stats.count("mediantxsize") != 0;
     const bool do_medianfee = do_all || stats.count("medianfee") != 0;
     const bool do_medianfeerate = do_all || stats.count("medianfeerate") != 0;
     const bool loop_inputs =
         do_all || do_medianfee || do_medianfeerate ||
         SetHasKeys(stats, "utxo_size_inc", "totalfee", "avgfee", "avgfeerate",
                    "minfee", "maxfee", "minfeerate", "maxfeerate");
     const bool loop_outputs = do_all || loop_inputs || stats.count("total_out");
     const bool do_calculate_size =
         do_mediantxsize || loop_inputs ||
         SetHasKeys(stats, "total_size", "avgtxsize", "mintxsize", "maxtxsize");
 
     const int64_t blockMaxSize = config.GetMaxBlockSize();
     Amount maxfee = Amount::zero();
     Amount maxfeerate = Amount::zero();
     Amount minfee = MAX_MONEY;
     Amount minfeerate = MAX_MONEY;
     Amount total_out = Amount::zero();
     Amount totalfee = Amount::zero();
     int64_t inputs = 0;
     int64_t maxtxsize = 0;
     int64_t mintxsize = blockMaxSize;
     int64_t outputs = 0;
     int64_t total_size = 0;
     int64_t utxo_size_inc = 0;
     std::vector<Amount> fee_array;
     std::vector<Amount> feerate_array;
     std::vector<int64_t> txsize_array;
 
     const Consensus::Params &params = config.GetChainParams().GetConsensus();
 
     for (const auto &tx : block.vtx) {
         outputs += tx->vout.size();
         Amount tx_total_out = Amount::zero();
         if (loop_outputs) {
             for (const CTxOut &out : tx->vout) {
                 tx_total_out += out.nValue;
                 utxo_size_inc +=
                     GetSerializeSize(out, PROTOCOL_VERSION) + PER_UTXO_OVERHEAD;
             }
         }
 
         if (tx->IsCoinBase()) {
             continue;
         }
 
         // Don't count coinbase's fake input
         inputs += tx->vin.size();
         // Don't count coinbase reward
         total_out += tx_total_out;
 
         int64_t tx_size = 0;
         if (do_calculate_size) {
             tx_size = tx->GetTotalSize();
             if (do_mediantxsize) {
                 txsize_array.push_back(tx_size);
             }
             maxtxsize = std::max(maxtxsize, tx_size);
             mintxsize = std::min(mintxsize, tx_size);
             total_size += tx_size;
         }
 
         if (loop_inputs) {
             if (!g_txindex) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER,
                                    "One or more of the selected stats requires "
                                    "-txindex enabled");
             }
 
             Amount tx_total_in = Amount::zero();
             for (const CTxIn &in : tx->vin) {
                 CTransactionRef tx_in;
                 BlockHash hashBlock;
                 if (!GetTransaction(in.prevout.GetTxId(), tx_in, params,
                                     hashBlock)) {
                     throw JSONRPCError(RPC_INTERNAL_ERROR,
                                        std::string("Unexpected internal error "
                                                    "(tx index seems corrupt)"));
                 }
 
                 CTxOut prevoutput = tx_in->vout[in.prevout.GetN()];
 
                 tx_total_in += prevoutput.nValue;
                 utxo_size_inc -=
                     GetSerializeSize(prevoutput, PROTOCOL_VERSION) +
                     PER_UTXO_OVERHEAD;
             }
 
             Amount txfee = tx_total_in - tx_total_out;
             assert(MoneyRange(txfee));
             if (do_medianfee) {
                 fee_array.push_back(txfee);
             }
             maxfee = std::max(maxfee, txfee);
             minfee = std::min(minfee, txfee);
             totalfee += txfee;
 
             Amount feerate = txfee / tx_size;
             if (do_medianfeerate) {
                 feerate_array.push_back(feerate);
             }
             maxfeerate = std::max(maxfeerate, feerate);
             minfeerate = std::min(minfeerate, feerate);
         }
     }
 
     UniValue ret_all(UniValue::VOBJ);
     ret_all.pushKV("avgfee",
                    ValueFromAmount((block.vtx.size() > 1)
                                        ? totalfee / int((block.vtx.size() - 1))
                                        : Amount::zero()));
     ret_all.pushKV("avgfeerate",
                    ValueFromAmount((total_size > 0) ? totalfee / total_size
                                                     : Amount::zero()));
     ret_all.pushKV("avgtxsize", (block.vtx.size() > 1)
                                     ? total_size / (block.vtx.size() - 1)
                                     : 0);
     ret_all.pushKV("blockhash", pindex->GetBlockHash().GetHex());
     ret_all.pushKV("height", (int64_t)pindex->nHeight);
     ret_all.pushKV("ins", inputs);
     ret_all.pushKV("maxfee", ValueFromAmount(maxfee));
     ret_all.pushKV("maxfeerate", ValueFromAmount(maxfeerate));
     ret_all.pushKV("maxtxsize", maxtxsize);
     ret_all.pushKV("medianfee",
                    ValueFromAmount(CalculateTruncatedMedian(fee_array)));
     ret_all.pushKV("medianfeerate",
                    ValueFromAmount(CalculateTruncatedMedian(feerate_array)));
     ret_all.pushKV("mediantime", pindex->GetMedianTimePast());
     ret_all.pushKV("mediantxsize", CalculateTruncatedMedian(txsize_array));
     ret_all.pushKV(
         "minfee",
         ValueFromAmount((minfee == MAX_MONEY) ? Amount::zero() : minfee));
     ret_all.pushKV("minfeerate",
                    ValueFromAmount((minfeerate == MAX_MONEY) ? Amount::zero()
                                                              : minfeerate));
     ret_all.pushKV("mintxsize", mintxsize == blockMaxSize ? 0 : mintxsize);
     ret_all.pushKV("outs", outputs);
     ret_all.pushKV("subsidy", ValueFromAmount(GetBlockSubsidy(
                                   pindex->nHeight, Params().GetConsensus())));
     ret_all.pushKV("time", pindex->GetBlockTime());
     ret_all.pushKV("total_out", ValueFromAmount(total_out));
     ret_all.pushKV("total_size", total_size);
     ret_all.pushKV("totalfee", ValueFromAmount(totalfee));
     ret_all.pushKV("txs", (int64_t)block.vtx.size());
     ret_all.pushKV("utxo_increase", outputs - inputs);
     ret_all.pushKV("utxo_size_inc", utxo_size_inc);
 
     if (do_all) {
         return ret_all;
     }
 
     UniValue ret(UniValue::VOBJ);
     for (const std::string &stat : stats) {
         const UniValue &value = ret_all[stat];
         if (value.isNull()) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Invalid selected statistic %s", stat));
         }
         ret.pushKV(stat, value);
     }
     return ret;
 }
 
 static UniValue savemempool(const Config &config,
                             const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(RPCHelpMan{
             "savemempool",
             "\nDumps the mempool to disk. It will fail until the "
             "previous dump is fully loaded.\n",
             {},
             RPCResults{},
             RPCExamples{HelpExampleCli("savemempool", "") +
                         HelpExampleRpc("savemempool", "")},
         }
                                      .ToString());
     }
 
     if (!::g_mempool.IsLoaded()) {
         throw JSONRPCError(RPC_MISC_ERROR, "The mempool was not loaded yet");
     }
 
     if (!DumpMempool(::g_mempool)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Unable to dump mempool to disk");
     }
 
     return NullUniValue;
 }
 
 //! Search for a given set of pubkey scripts
 static bool FindScriptPubKey(std::atomic<int> &scan_progress,
                              const std::atomic<bool> &should_abort,
                              int64_t &count, CCoinsViewCursor *cursor,
                              const std::set<CScript> &needles,
                              std::map<COutPoint, Coin> &out_results) {
     scan_progress = 0;
     count = 0;
     while (cursor->Valid()) {
         COutPoint key;
         Coin coin;
         if (!cursor->GetKey(key) || !cursor->GetValue(coin)) {
             return false;
         }
         if (++count % 8192 == 0) {
             boost::this_thread::interruption_point();
             if (should_abort) {
                 // allow to abort the scan via the abort reference
                 return false;
             }
         }
         if (count % 256 == 0) {
             // update progress reference every 256 item
             const TxId &txid = key.GetTxId();
             uint32_t high = 0x100 * *txid.begin() + *(txid.begin() + 1);
             scan_progress = int(high * 100.0 / 65536.0 + 0.5);
         }
         if (needles.count(coin.GetTxOut().scriptPubKey)) {
             out_results.emplace(key, coin);
         }
         cursor->Next();
     }
     scan_progress = 100;
     return true;
 }
 
 /** RAII object to prevent concurrency issue when scanning the txout set */
 static std::mutex g_utxosetscan;
 static std::atomic<int> g_scan_progress;
 static std::atomic<bool> g_scan_in_progress;
 static std::atomic<bool> g_should_abort_scan;
 class CoinsViewScanReserver {
 private:
     bool m_could_reserve;
 
 public:
     explicit CoinsViewScanReserver() : m_could_reserve(false) {}
 
     bool reserve() {
         assert(!m_could_reserve);
         std::lock_guard<std::mutex> lock(g_utxosetscan);
         if (g_scan_in_progress) {
             return false;
         }
         g_scan_in_progress = true;
         m_could_reserve = true;
         return true;
     }
 
     ~CoinsViewScanReserver() {
         if (m_could_reserve) {
             std::lock_guard<std::mutex> lock(g_utxosetscan);
             g_scan_in_progress = false;
         }
     }
 };
 
 static UniValue scantxoutset(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(RPCHelpMan{
             "scantxoutset",
             "\nEXPERIMENTAL warning: this call may be removed or changed "
             "in future releases.\n"
             "\nScans the unspent transaction output set for entries that "
             "match certain output descriptors.\n"
             "Examples of output descriptors are:\n"
             "    addr(<address>)                      Outputs whose "
             "scriptPubKey corresponds to the specified address (does not "
             "include P2PK)\n"
             "    raw(<hex script>)                    Outputs whose "
             "scriptPubKey equals the specified hex scripts\n"
             "    combo(<pubkey>)                      P2PK and P2PKH "
             "outputs for the given pubkey\n"
             "    pkh(<pubkey>)                        P2PKH outputs for "
             "the given pubkey\n"
             "    sh(multi(<n>,<pubkey>,<pubkey>,...)) P2SH-multisig "
             "outputs for the given threshold and pubkeys\n"
             "\nIn the above, <pubkey> either refers to a fixed public key "
             "in hexadecimal notation, or to an xpub/xprv optionally "
             "followed by one\n"
             "or more path elements separated by \"/\", and optionally "
             "ending in \"/*\" (unhardened), or \"/*'\" or \"/*h\" "
             "(hardened) to specify all\n"
             "unhardened or hardened child keys.\n"
             "In the latter case, a range needs to be specified by below if "
             "different from 1000.\n"
             "For more information on output descriptors, see the "
             "documentation in the doc/descriptors.md file.\n",
             {
                 {"action", RPCArg::Type::STR, RPCArg::Optional::NO,
                  "The action to execute\n"
                  "                                      \"start\" for "
                  "starting a scan\n"
                  "                                      \"abort\" for "
                  "aborting the current scan (returns true when abort was "
                  "successful)\n"
                  "                                      \"status\" for "
                  "progress report (in %) of the current scan"},
                 {"scanobjects",
                  RPCArg::Type::ARR,
                  RPCArg::Optional::NO,
                  "Array of scan objects\n"
                  "                                  Every scan object is "
                  "either a string descriptor or an object:",
                  {
                      {"descriptor", RPCArg::Type::STR,
                       RPCArg::Optional::OMITTED, "An output descriptor"},
                      {
                          "",
                          RPCArg::Type::OBJ,
                          RPCArg::Optional::OMITTED,
                          "An object with output descriptor and metadata",
                          {
                              {"desc", RPCArg::Type::STR, RPCArg::Optional::NO,
                               "An output descriptor"},
                              {"range", RPCArg::Type::NUM, /* default */ "1000",
                               "Up to what child index HD chains should be "
                               "explored"},
                          },
                      },
                  },
                  "[scanobjects,...]"},
             },
             RPCResult{
                 "{\n"
                 "  \"unspents\": [\n"
                 "    {\n"
                 "    \"txid\" : \"transactionid\",     (string) The "
                 "transaction id\n"
                 "    \"vout\": n,                    (numeric) the vout value\n"
                 "    \"scriptPubKey\" : \"script\",    (string) the script "
                 "key\n"
                 "    \"desc\" : \"descriptor\",        (string) A specialized "
                 "descriptor for the matched scriptPubKey\n"
                 "    \"amount\" : x.xxx,             (numeric) The total "
                 "amount in " +
                 CURRENCY_UNIT +
                 " of the unspent output\n"
                 "    \"height\" : n,                 (numeric) Height of the "
                 "unspent transaction output\n"
                 "   }\n"
                 "   ,...], \n"
                 " \"total_amount\" : x.xxx,          (numeric) The total "
                 "amount of all found unspent outputs in " +
                 CURRENCY_UNIT +
                 "\n"
                 "]\n"},
             RPCExamples{""},
         }
                                      .ToString());
     }
 
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VARR});
 
     UniValue result(UniValue::VOBJ);
     if (request.params[0].get_str() == "status") {
         CoinsViewScanReserver reserver;
         if (reserver.reserve()) {
             // no scan in progress
             return NullUniValue;
         }
         result.pushKV("progress", g_scan_progress.load());
         return result;
     } else if (request.params[0].get_str() == "abort") {
         CoinsViewScanReserver reserver;
         if (reserver.reserve()) {
             // reserve was possible which means no scan was running
             return false;
         }
         // set the abort flag
         g_should_abort_scan = true;
         return true;
     } else if (request.params[0].get_str() == "start") {
         CoinsViewScanReserver reserver;
         if (!reserver.reserve()) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Scan already in progress, use action \"abort\" or \"status\"");
         }
         std::set<CScript> needles;
         std::map<CScript, std::string> descriptors;
         Amount total_in = Amount::zero();
 
         // loop through the scan objects
         for (const UniValue &scanobject :
              request.params[1].get_array().getValues()) {
             std::string desc_str;
             int range = 1000;
             if (scanobject.isStr()) {
                 desc_str = scanobject.get_str();
             } else if (scanobject.isObject()) {
                 UniValue desc_uni = find_value(scanobject, "desc");
                 if (desc_uni.isNull()) {
                     throw JSONRPCError(
                         RPC_INVALID_PARAMETER,
                         "Descriptor needs to be provided in scan object");
                 }
                 desc_str = desc_uni.get_str();
                 UniValue range_uni = find_value(scanobject, "range");
                 if (!range_uni.isNull()) {
                     range = range_uni.get_int();
                     if (range < 0 || range > 1000000) {
                         throw JSONRPCError(RPC_INVALID_PARAMETER,
                                            "range out of range");
                     }
                 }
             } else {
                 throw JSONRPCError(
                     RPC_INVALID_PARAMETER,
                     "Scan object needs to be either a string or an object");
             }
 
             FlatSigningProvider provider;
             auto desc = Parse(desc_str, provider);
             if (!desc) {
                 throw JSONRPCError(
                     RPC_INVALID_ADDRESS_OR_KEY,
                     strprintf("Invalid descriptor '%s'", desc_str));
             }
             if (!desc->IsRange()) {
                 range = 0;
             }
             for (int i = 0; i <= range; ++i) {
                 std::vector<CScript> scripts;
                 if (!desc->Expand(i, provider, scripts, provider)) {
                     throw JSONRPCError(
                         RPC_INVALID_ADDRESS_OR_KEY,
                         strprintf(
                             "Cannot derive script without private keys: '%s'",
                             desc_str));
                 }
                 for (const auto &script : scripts) {
                     std::string inferred =
                         InferDescriptor(script, provider)->ToString();
                     needles.emplace(script);
                     descriptors.emplace(std::move(script), std::move(inferred));
                 }
             }
         }
 
         // Scan the unspent transaction output set for inputs
         UniValue unspents(UniValue::VARR);
         std::vector<CTxOut> input_txos;
         std::map<COutPoint, Coin> coins;
         g_should_abort_scan = false;
         g_scan_progress = 0;
         int64_t count = 0;
         std::unique_ptr<CCoinsViewCursor> pcursor;
         {
             LOCK(cs_main);
             ::ChainstateActive().ForceFlushStateToDisk();
             pcursor = std::unique_ptr<CCoinsViewCursor>(pcoinsdbview->Cursor());
             assert(pcursor);
         }
         bool res = FindScriptPubKey(g_scan_progress, g_should_abort_scan, count,
                                     pcursor.get(), needles, coins);
         result.pushKV("success", res);
         result.pushKV("searched_items", count);
 
         for (const auto &it : coins) {
             const COutPoint &outpoint = it.first;
             const Coin &coin = it.second;
             const CTxOut &txo = coin.GetTxOut();
             input_txos.push_back(txo);
             total_in += txo.nValue;
 
             UniValue unspent(UniValue::VOBJ);
             unspent.pushKV("txid", outpoint.GetTxId().GetHex());
             unspent.pushKV("vout", int32_t(outpoint.GetN()));
             unspent.pushKV("scriptPubKey", HexStr(txo.scriptPubKey.begin(),
                                                   txo.scriptPubKey.end()));
             unspent.pushKV("desc", descriptors[txo.scriptPubKey]);
             unspent.pushKV("amount", ValueFromAmount(txo.nValue));
             unspent.pushKV("height", int32_t(coin.GetHeight()));
 
             unspents.push_back(unspent);
         }
         result.pushKV("unspents", unspents);
         result.pushKV("total_amount", ValueFromAmount(total_in));
     } else {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid command");
     }
     return result;
 }
 
 // clang-format off
 static const CRPCCommand commands[] = {
     //  category            name                      actor (function)        argNames
     //  ------------------- ------------------------  ----------------------  ----------
     { "blockchain",         "getbestblockhash",       getbestblockhash,       {} },
     { "blockchain",         "getblock",               getblock,               {"blockhash","verbosity|verbose"} },
     { "blockchain",         "getblockchaininfo",      getblockchaininfo,      {} },
     { "blockchain",         "getblockcount",          getblockcount,          {} },
     { "blockchain",         "getblockhash",           getblockhash,           {"height"} },
     { "blockchain",         "getblockheader",         getblockheader,         {"blockhash","verbose"} },
     { "blockchain",         "getblockstats",          getblockstats,          {"hash_or_height","stats"} },
     { "blockchain",         "getchaintips",           getchaintips,           {} },
     { "blockchain",         "getchaintxstats",        getchaintxstats,        {"nblocks", "blockhash"} },
     { "blockchain",         "getdifficulty",          getdifficulty,          {} },
     { "blockchain",         "getmempoolancestors",    getmempoolancestors,    {"txid","verbose"} },
     { "blockchain",         "getmempooldescendants",  getmempooldescendants,  {"txid","verbose"} },
     { "blockchain",         "getmempoolentry",        getmempoolentry,        {"txid"} },
     { "blockchain",         "getmempoolinfo",         getmempoolinfo,         {} },
     { "blockchain",         "getrawmempool",          getrawmempool,          {"verbose"} },
     { "blockchain",         "gettxout",               gettxout,               {"txid","n","include_mempool"} },
     { "blockchain",         "gettxoutsetinfo",        gettxoutsetinfo,        {} },
     { "blockchain",         "pruneblockchain",        pruneblockchain,        {"height"} },
     { "blockchain",         "savemempool",            savemempool,            {} },
     { "blockchain",         "verifychain",            verifychain,            {"checklevel","nblocks"} },
     { "blockchain",         "preciousblock",          preciousblock,          {"blockhash"} },
     { "blockchain",         "scantxoutset",           scantxoutset,           {"action", "scanobjects"} },
 
     /* Not shown in help */
     { "hidden",             "getfinalizedblockhash",            getfinalizedblockhash,            {} },
     { "hidden",             "finalizeblock",                    finalizeblock,                    {"blockhash"} },
     { "hidden",             "invalidateblock",                  invalidateblock,                  {"blockhash"} },
     { "hidden",             "parkblock",                        parkblock,                        {"blockhash"} },
     { "hidden",             "reconsiderblock",                  reconsiderblock,                  {"blockhash"} },
     { "hidden",             "syncwithvalidationinterfacequeue", syncwithvalidationinterfacequeue, {} },
     { "hidden",             "unparkblock",                      unparkblock,                      {"blockhash"} },
     { "hidden",             "waitfornewblock",                  waitfornewblock,                  {"timeout"} },
     { "hidden",             "waitforblock",                     waitforblock,                     {"blockhash","timeout"} },
     { "hidden",             "waitforblockheight",               waitforblockheight,               {"height","timeout"} },
 };
 // clang-format on
 
 void RegisterBlockchainRPCCommands(CRPCTable &t) {
     for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++) {
         t.appendCommand(commands[vcidx].name, &commands[vcidx]);
     }
 }
diff --git a/src/test/skiplist_tests.cpp b/src/test/skiplist_tests.cpp
index 98a7ce0c9..ca00fcedf 100644
--- a/src/test/skiplist_tests.cpp
+++ b/src/test/skiplist_tests.cpp
@@ -1,214 +1,223 @@
 // Copyright (c) 2014-2019 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 <util/system.h>
 
 #include <test/setup_common.h>
 
 #include <boost/test/unit_test.hpp>
 
 #include <vector>
 
 #define SKIPLIST_LENGTH 300000
 
 BOOST_FIXTURE_TEST_SUITE(skiplist_tests, BasicTestingSetup)
 
 BOOST_AUTO_TEST_CASE(skiplist_test) {
     std::vector<CBlockIndex> vIndex(SKIPLIST_LENGTH);
 
     for (int i = 0; i < SKIPLIST_LENGTH; i++) {
         vIndex[i].nHeight = i;
         vIndex[i].pprev = (i == 0) ? nullptr : &vIndex[i - 1];
         vIndex[i].BuildSkip();
     }
 
     for (int i = 0; i < SKIPLIST_LENGTH; i++) {
         if (i > 0) {
             BOOST_CHECK(vIndex[i].pskip == &vIndex[vIndex[i].pskip->nHeight]);
             BOOST_CHECK(vIndex[i].pskip->nHeight < i);
         } else {
             BOOST_CHECK(vIndex[i].pskip == nullptr);
         }
     }
 
     for (int i = 0; i < 1000; i++) {
         int from = InsecureRandRange(SKIPLIST_LENGTH - 1);
         int to = InsecureRandRange(from + 1);
 
         BOOST_CHECK(vIndex[SKIPLIST_LENGTH - 1].GetAncestor(from) ==
                     &vIndex[from]);
         BOOST_CHECK(vIndex[from].GetAncestor(to) == &vIndex[to]);
         BOOST_CHECK(vIndex[from].GetAncestor(0) == vIndex.data());
     }
 }
 
 BOOST_AUTO_TEST_CASE(getlocator_test) {
     // Build a main chain 100000 blocks long.
     std::vector<BlockHash> vHashMain(100000);
     std::vector<CBlockIndex> vBlocksMain(100000);
     for (size_t i = 0; i < vBlocksMain.size(); i++) {
         // Set the hash equal to the height, so we can quickly check the
         // distances.
         vHashMain[i] = BlockHash(ArithToUint256(i));
         vBlocksMain[i].nHeight = i;
         vBlocksMain[i].pprev = i ? &vBlocksMain[i - 1] : nullptr;
         vBlocksMain[i].phashBlock = &vHashMain[i];
         vBlocksMain[i].BuildSkip();
         BOOST_CHECK_EQUAL(
             (int)UintToArith256(vBlocksMain[i].GetBlockHash()).GetLow64(),
             vBlocksMain[i].nHeight);
         BOOST_CHECK(vBlocksMain[i].pprev == nullptr ||
                     vBlocksMain[i].nHeight ==
                         vBlocksMain[i].pprev->nHeight + 1);
     }
 
     // Build a branch that splits off at block 49999, 50000 blocks long.
     std::vector<BlockHash> vHashSide(50000);
     std::vector<CBlockIndex> vBlocksSide(50000);
     for (size_t i = 0; i < vBlocksSide.size(); i++) {
         // Add 1<<128 to the hashes, so GetLow64() still returns the height.
         vHashSide[i] =
             BlockHash(ArithToUint256(i + 50000 + (arith_uint256(1) << 128)));
         vBlocksSide[i].nHeight = i + 50000;
         vBlocksSide[i].pprev =
             i ? &vBlocksSide[i - 1] : (vBlocksMain.data() + 49999);
         vBlocksSide[i].phashBlock = &vHashSide[i];
         vBlocksSide[i].BuildSkip();
         BOOST_CHECK_EQUAL(
             (int)UintToArith256(vBlocksSide[i].GetBlockHash()).GetLow64(),
             vBlocksSide[i].nHeight);
         BOOST_CHECK(vBlocksSide[i].pprev == nullptr ||
                     vBlocksSide[i].nHeight ==
                         vBlocksSide[i].pprev->nHeight + 1);
     }
 
     // Build a CChain for the main branch.
     CChain chain;
     chain.SetTip(&vBlocksMain.back());
 
     // Test 100 random starting points for locators.
     for (int n = 0; n < 100; n++) {
         int r = InsecureRandRange(150000);
         CBlockIndex *tip =
             (r < 100000) ? &vBlocksMain[r] : &vBlocksSide[r - 100000];
         CBlockLocator locator = chain.GetLocator(tip);
 
         // The first result must be the block itself, the last one must be
         // genesis.
         BOOST_CHECK(locator.vHave.front() == tip->GetBlockHash());
         BOOST_CHECK(locator.vHave.back() == vBlocksMain[0].GetBlockHash());
 
         // Entries 1 through 11 (inclusive) go back one step each.
         for (unsigned int i = 1; i < 12 && i < locator.vHave.size() - 1; i++) {
             BOOST_CHECK_EQUAL(UintToArith256(locator.vHave[i]).GetLow64(),
                               tip->nHeight - i);
         }
 
         // The further ones (excluding the last one) go back with exponential
         // steps.
         unsigned int dist = 2;
         for (size_t i = 12; i < locator.vHave.size() - 1; i++) {
             BOOST_CHECK_EQUAL(UintToArith256(locator.vHave[i - 1]).GetLow64() -
                                   UintToArith256(locator.vHave[i]).GetLow64(),
                               dist);
             dist *= 2;
         }
     }
 }
 
 BOOST_AUTO_TEST_CASE(findearliestatleast_test) {
     std::vector<BlockHash> vHashMain(100000);
     std::vector<CBlockIndex> vBlocksMain(100000);
     for (size_t i = 0; i < vBlocksMain.size(); i++) {
         // Set the hash equal to the height
         vHashMain[i] = BlockHash(ArithToUint256(i));
         vBlocksMain[i].nHeight = i;
         vBlocksMain[i].pprev = i ? &vBlocksMain[i - 1] : nullptr;
         vBlocksMain[i].phashBlock = &vHashMain[i];
         vBlocksMain[i].BuildSkip();
         if (i < 10) {
             vBlocksMain[i].nTime = i;
             vBlocksMain[i].nTimeMax = i;
         } else {
             // randomly choose something in the range [MTP, MTP*2]
             int64_t medianTimePast = vBlocksMain[i].GetMedianTimePast();
             int r = InsecureRandRange(medianTimePast);
             vBlocksMain[i].nTime = r + medianTimePast;
             vBlocksMain[i].nTimeMax =
                 std::max(vBlocksMain[i].nTime, vBlocksMain[i - 1].nTimeMax);
         }
     }
     // Check that we set nTimeMax up correctly.
     unsigned int curTimeMax = 0;
     for (size_t i = 0; i < vBlocksMain.size(); ++i) {
         curTimeMax = std::max(curTimeMax, vBlocksMain[i].nTime);
         BOOST_CHECK(curTimeMax == vBlocksMain[i].nTimeMax);
     }
 
     // Build a CChain for the main branch.
     CChain chain;
     chain.SetTip(&vBlocksMain.back());
 
     // Verify that FindEarliestAtLeast is correct.
     for (unsigned int i = 0; i < 10000; ++i) {
         // Pick a random element in vBlocksMain.
         int r = InsecureRandRange(vBlocksMain.size());
         int64_t test_time = vBlocksMain[r].nTime;
-        CBlockIndex *ret = chain.FindEarliestAtLeast(test_time);
+        CBlockIndex *ret = chain.FindEarliestAtLeast(test_time, 0);
         BOOST_CHECK(ret->nTimeMax >= test_time);
         BOOST_CHECK((ret->pprev == nullptr) ||
                     ret->pprev->nTimeMax < test_time);
         BOOST_CHECK(vBlocksMain[r].GetAncestor(ret->nHeight) == ret);
     }
 }
 
 BOOST_AUTO_TEST_CASE(findearliestatleast_edge_test) {
     std::list<CBlockIndex> blocks;
     for (const unsigned int timeMax :
          {100, 100, 100, 200, 200, 200, 300, 300, 300}) {
         CBlockIndex *prev = blocks.empty() ? nullptr : &blocks.back();
         blocks.emplace_back();
         blocks.back().nHeight = prev ? prev->nHeight + 1 : 0;
         blocks.back().pprev = prev;
         blocks.back().BuildSkip();
         blocks.back().nTimeMax = timeMax;
     }
 
     CChain chain;
     chain.SetTip(&blocks.back());
 
-    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(50)->nHeight, 0);
-    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(100)->nHeight, 0);
-    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(150)->nHeight, 3);
-    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(200)->nHeight, 3);
-    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(250)->nHeight, 6);
-    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(300)->nHeight, 6);
-    BOOST_CHECK(!chain.FindEarliestAtLeast(350));
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(50, 0)->nHeight, 0);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(100, 0)->nHeight, 0);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(150, 0)->nHeight, 3);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(200, 0)->nHeight, 3);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(250, 0)->nHeight, 6);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(300, 0)->nHeight, 6);
+    BOOST_CHECK(!chain.FindEarliestAtLeast(350, 0));
 
-    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0)->nHeight, 0);
-    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(-1)->nHeight, 0);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, 0)->nHeight, 0);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(-1, 0)->nHeight, 0);
 
     BOOST_CHECK_EQUAL(
-        chain.FindEarliestAtLeast(std::numeric_limits<int64_t>::min())->nHeight,
-        0);
-    BOOST_CHECK_EQUAL(
-        chain.FindEarliestAtLeast(std::numeric_limits<unsigned int>::min())
+        chain.FindEarliestAtLeast(std::numeric_limits<int64_t>::min(), 0)
             ->nHeight,
         0);
     BOOST_CHECK_EQUAL(
         chain
             .FindEarliestAtLeast(
-                -int64_t(std::numeric_limits<unsigned int>::max()) - 1)
+                -int64_t(std::numeric_limits<unsigned int>::max()) - 1, 0)
             ->nHeight,
         0);
     BOOST_CHECK(
-        !chain.FindEarliestAtLeast(std::numeric_limits<int64_t>::max()));
-    BOOST_CHECK(
-        !chain.FindEarliestAtLeast(std::numeric_limits<unsigned int>::max()));
+        !chain.FindEarliestAtLeast(std::numeric_limits<int64_t>::max(), 0));
+    BOOST_CHECK(!chain.FindEarliestAtLeast(
+        std::numeric_limits<unsigned int>::max(), 0));
     BOOST_CHECK(!chain.FindEarliestAtLeast(
-        int64_t(std::numeric_limits<unsigned int>::max()) + 1));
+        int64_t(std::numeric_limits<unsigned int>::max()) + 1, 0));
+
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, -1)->nHeight, 0);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, 0)->nHeight, 0);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, 3)->nHeight, 3);
+    BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, 8)->nHeight, 8);
+    BOOST_CHECK(!chain.FindEarliestAtLeast(0, 9));
+
+    CBlockIndex *ret1 = chain.FindEarliestAtLeast(100, 2);
+    BOOST_CHECK(ret1->nTimeMax >= 100 && ret1->nHeight == 2);
+    BOOST_CHECK(!chain.FindEarliestAtLeast(300, 9));
+    CBlockIndex *ret2 = chain.FindEarliestAtLeast(200, 4);
+    BOOST_CHECK(ret2->nTimeMax >= 200 && ret2->nHeight == 4);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 378c48a7e..33c5ef3ff 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1,4996 +1,4997 @@
 // 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 <interfaces/wallet.h>
 #include <key.h>
 #include <key_io.h>
 #include <keystore.h>
 #include <net.h>
 #include <policy/mempool.h>
 #include <policy/policy.h>
 #include <policy/settings.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/bip32.h>
 #include <util/error.h>
 #include <util/moneystr.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <util/validation.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/coinselection.h>
 #include <wallet/fees.h>
 
 #include <boost/algorithm/string/replace.hpp>
 
 #include <algorithm>
 #include <cassert>
 #include <future>
 
 static RecursiveMutex 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();
     wallet->m_chain_notifications_handler.reset();
     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;
 
 std::shared_ptr<CWallet> LoadWallet(const CChainParams &chainParams,
                                     interfaces::Chain &chain,
                                     const WalletLocation &location,
                                     std::string &error, std::string &warning) {
     if (!CWallet::Verify(chainParams, chain, location, false, error, warning)) {
         error = "Wallet file verification failed: " + error;
         return nullptr;
     }
 
     std::shared_ptr<CWallet> wallet =
         CWallet::CreateWalletFromFile(chainParams, chain, location);
     if (!wallet) {
         error = "Wallet loading failed.";
         return nullptr;
     }
     AddWallet(wallet);
     wallet->postInitProcess();
     return wallet;
 }
 
 std::shared_ptr<CWallet> LoadWallet(const CChainParams &chainParams,
                                     interfaces::Chain &chain,
                                     const std::string &name, std::string &error,
                                     std::string &warning) {
     return LoadWallet(chainParams, chain, WalletLocation(name), error, warning);
 }
 
 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) +
                                  "'";
             metadata.key_origin.path.push_back(0 | BIP32_HARDENED_KEY_LIMIT);
             metadata.key_origin.path.push_back(1 | BIP32_HARDENED_KEY_LIMIT);
             metadata.key_origin.path.push_back(hdChain.nInternalChainCounter |
                                                BIP32_HARDENED_KEY_LIMIT);
             hdChain.nInternalChainCounter++;
         } else {
             chainChildKey.Derive(childKey, hdChain.nExternalChainCounter |
                                                BIP32_HARDENED_KEY_LIMIT);
             metadata.hdKeypath = "m/0'/0'/" +
                                  std::to_string(hdChain.nExternalChainCounter) +
                                  "'";
             metadata.key_origin.path.push_back(0 | BIP32_HARDENED_KEY_LIMIT);
             metadata.key_origin.path.push_back(0 | BIP32_HARDENED_KEY_LIMIT);
             metadata.key_origin.path.push_back(hdChain.nExternalChainCounter |
                                                BIP32_HARDENED_KEY_LIMIT);
             hdChain.nExternalChainCounter++;
         }
     } while (HaveKey(childKey.key.GetPubKey().GetID()));
     secret = childKey.key;
     metadata.hd_seed_id = hdChain.seed_id;
     CKeyID master_id = masterKey.key.GetPubKey().GetID();
     std::copy(master_id.begin(), master_id.begin() + 4,
               metadata.key_origin.fingerprint);
     metadata.has_key_origin = true;
     // 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;
 }
 
 // Writes a keymetadata for a public key. overwrite specifies whether to
 // overwrite an existing metadata for that key if there exists one.
 bool CWallet::WriteKeyMetadata(const CKeyMetadata &meta, const CPubKey &pubkey,
                                const bool overwrite) {
     return WalletBatch(*database).WriteKeyMetadata(meta, pubkey, overwrite);
 }
 
 void CWallet::UpgradeKeyMetadata() {
     // mapKeyMetadata
     AssertLockHeld(cs_wallet);
     if (IsLocked() || IsWalletFlagSet(WALLET_FLAG_KEY_ORIGIN_METADATA)) {
         return;
     }
 
     for (auto &meta_pair : mapKeyMetadata) {
         CKeyMetadata &meta = meta_pair.second;
         // If the hdKeypath is "s", that's the seed and it doesn't have a key
         // origin
         if (!meta.hd_seed_id.IsNull() && !meta.has_key_origin &&
             meta.hdKeypath != "s") {
             CKey key;
             GetKey(meta.hd_seed_id, key);
             CExtKey masterKey;
             masterKey.SetSeed(key.begin(), key.size());
             // Add to map
             CKeyID master_id = masterKey.key.GetPubKey().GetID();
             std::copy(master_id.begin(), master_id.begin() + 4,
                       meta.key_origin.fingerprint);
             if (!ParseHDKeypath(meta.hdKeypath, meta.key_origin.path)) {
                 throw std::runtime_error("Invalid stored hdKeypath");
             }
             meta.has_key_origin = true;
             if (meta.nVersion < CKeyMetadata::VERSION_WITH_KEY_ORIGIN) {
                 meta.nVersion = CKeyMetadata::VERSION_WITH_KEY_ORIGIN;
             }
 
             // Write meta to wallet
             CPubKey pubkey;
             if (GetPubKey(meta_pair.first, pubkey)) {
                 WriteKeyMetadata(meta, pubkey, true);
             }
         }
     }
     SetWalletFlag(WALLET_FLAG_KEY_ORIGIN_METADATA);
 }
 
 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,
                      bool accept_no_keys) {
     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, accept_no_keys)) {
                 // Now that we've unlocked, upgrade the key metadata
                 UpgradeKeyMetadata();
                 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 = chain().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 BlockHash &block_hash,
                                        int posInBlock, bool fUpdate) {
     const CTransaction &tx = *ptx;
     AssertLockHeld(cs_wallet);
 
     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(), block_hash.ToString(),
                         range.first->second.ToString(),
                         range.first->first.GetTxId().ToString(),
                         range.first->first.GetN());
                     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 (!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 = -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 BlockHash &block_hash, int posInBlock,
                               bool 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, 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 CBlock &block, const std::vector<CTransactionRef> &vtxConflicted) {
     const BlockHash &block_hash = block.GetHash();
     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, BlockHash(), 0 /* position in block */);
         TransactionRemovedFromMempool(ptx);
     }
 
     for (size_t i = 0; i < block.vtx.size(); i++) {
         SyncTransaction(block.vtx[i], block_hash, i);
         TransactionRemovedFromMempool(block.vtx[i]);
     }
 
     m_last_block_processed = block_hash;
 }
 
 void CWallet::BlockDisconnected(const CBlock &block) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     for (const CTransactionRef &ptx : block.vtx) {
         SyncTransaction(ptx, BlockHash(), 0 /* position in block */);
     }
 }
 
 void CWallet::UpdatedBlockTip() {
     m_best_block_time = GetTime();
 }
 
 void CWallet::BlockUntilSyncedToCurrentChain() {
     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();
         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).
     chain().waitForNotifications();
 }
 
 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.has_key_origin = false;
     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.
     BlockHash start_block;
     {
         auto locked_chain = chain().lock();
-        const Optional<int> start_height = locked_chain->findFirstBlockWithTime(
-            startTime - TIMESTAMP_WINDOW, &start_block);
+        const Optional<int> start_height =
+            locked_chain->findFirstBlockWithTimeAndHeight(
+                startTime - TIMESTAMP_WINDOW, 0, &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 (!start_block.IsNull()) {
         // TODO: this should take into account failure by ScanResult::USER_ABORT
         ScanResult result = ScanForWalletTransactions(start_block, BlockHash(),
                                                       reserver, update);
         if (result.status == ScanResult::FAILURE) {
             int64_t time_max;
             if (!chain().findBlock(result.last_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 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] start_block Scan starting block. If block is not on the active
  *                        chain, the scan will return SUCCESS immediately.
  * @param[in] stop_block  Scan ending block. If block is not on the active
  *                        chain, the scan will continue until it reaches the
  *                        chain tip.
  *
  * @return ScanResult returning scan information and indicating success or
  *         failure. Return status will be set to 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 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 BlockHash &start_block, const BlockHash &stop_block,
     const WalletRescanReserver &reserver, bool fUpdate) {
     int64_t nNow = GetTime();
 
     assert(reserver.isReserved());
 
     BlockHash block_hash = start_block;
     ScanResult result;
 
     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...").translated, GetDisplayName()),
             0);
         BlockHash tip_hash;
         // The way the 'block_height' is initialized is just a workaround for
         // the gcc bug #47679 since version 4.6.0.
         Optional<int> block_height = MakeOptional(false, int());
         double progress_begin;
         double progress_end;
         {
             auto locked_chain = chain().lock();
             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 (block_height && !fAbortRescan && !chain().shutdownRequested()) {
             if (*block_height % 100 == 0 &&
                 progress_end - progress_begin > 0.0) {
                 ShowProgress(
                     strprintf("%s " + _("Rescanning...").translated,
                               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",
                                 *block_height, progress_current);
             }
 
             CBlock block;
             if (chain().findBlock(block_hash, &block) && !block.IsNull()) {
                 auto locked_chain = chain().lock();
                 LOCK(cs_wallet);
                 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.
                     // TODO: This should return success instead of failure, see
                     // https://github.com/bitcoin/bitcoin/pull/14711#issuecomment-458342518
                     result.last_failed_block = block_hash;
                     result.status = ScanResult::FAILURE;
                     break;
                 }
                 for (size_t posInBlock = 0; posInBlock < block.vtx.size();
                      ++posInBlock) {
                     SyncTransaction(block.vtx[posInBlock], block_hash,
                                     posInBlock, fUpdate);
                 }
                 // scan succeeded, record block as most recent successfully
                 // scanned
                 result.last_scanned_block = block_hash;
                 result.last_scanned_height = *block_height;
             } else {
                 // could not scan block, keep scanning but record this block as
                 // the most recent failure
                 result.last_failed_block = block_hash;
                 result.status = ScanResult::FAILURE;
             }
             if (block_hash == stop_block) {
                 break;
             }
             {
                 auto locked_chain = chain().lock();
                 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 =
                     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 = chain().guessVerificationProgress(tip_hash);
                 }
             }
         }
 
         // Hide progress dialog in GUI.
         ShowProgress(
             strprintf("%s " + _("Rescanning...").translated, GetDisplayName()),
             100);
         if (block_height && fAbortRescan) {
             WalletLogPrintf("Rescan aborted at block %d. Progress=%f\n",
                             *block_height, progress_current);
             result.status = ScanResult::USER_ABORT;
         } else if (block_height && chain().shutdownRequested()) {
             WalletLogPrintf("Rescan interrupted by shutdown request at block "
                             "%d. Progress=%f\n",
                             *block_height, progress_current);
             result.status = ScanResult::USER_ABORT;
         }
     }
 
     return result;
 }
 
 void CWallet::ReacceptWalletTransactions(
     interfaces::Chain::Lock &locked_chain) {
     // If transactions aren't being broadcasted, don't let them into local
     // mempool either.
     if (!fBroadcastTransactions) {
         return;
     }
 
     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, state);
     }
 }
 
 bool CWalletTx::RelayWalletTransaction(interfaces::Chain::Lock &locked_chain) {
     assert(pwallet->GetBroadcastTransactions());
     if (IsCoinBase() || isAbandoned() ||
         GetDepthInMainChain(locked_chain) != 0) {
         return false;
     }
 
     CValidationState state;
     // GetDepthInMainChain already catches known conflicts.
     if (InMempool() || AcceptToMemoryPool(locked_chain, state)) {
         pwallet->WalletLogPrintf("Relaying wtx %s\n", GetId().ToString());
         if (pwallet->chain().p2pEnabled()) {
             pwallet->chain().relayTransaction(GetId());
             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 {
     // Quick answer in most cases
     CValidationState state;
     if (!locked_chain.contextualCheckTransactionForCurrentBlock(
             Params().GetConsensus(), *tx, state)) {
         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);
 }
 
 // Rebroadcast transactions from the wallet. We do this on a random timer
 // to slightly obfuscate which transactions come from our wallet.
 //
 // Ideally, we'd only resend transactions that we think should have been
 // mined in the most recent block. Any transaction that wasn't in the top
 // blockweight of transactions in the mempool shouldn't have been mined,
 // and so is probably just sitting in the mempool waiting to be confirmed.
 // Rebroadcasting does nothing to speed up confirmation and only damages
 // privacy.
 void CWallet::ResendWalletTransactions() {
     // During reindex, importing and IBD, old wallet transactions become
     // unconfirmed. Don't resend them as that would spam other nodes.
     if (!chain().isReadyToBroadcast()) {
         return;
     }
 
     // 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 (m_best_block_time < nLastResend) {
         return;
     }
 
     nLastResend = GetTime();
 
     int relayed_tx_count = 0;
 
     { // locked_chain and cs_wallet scope
         auto locked_chain = chain().lock();
         LOCK(cs_wallet);
 
         // Relay transactions
         for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
             CWalletTx &wtx = item.second;
             // only rebroadcast unconfirmed txes older than 5 minutes before the
             // last block was found
             if (wtx.nTimeReceived > m_best_block_time - 5 * 60) {
                 continue;
             }
             if (wtx.RelayWalletTransaction(*locked_chain)) {
                 ++relayed_tx_count;
             }
         }
     } // locked_chain and cs_wallet
 
     if (relayed_tx_count > 0) {
         WalletLogPrintf("%s: rebroadcast %u unconfirmed transactions\n",
                         __func__, relayed_tx_count);
     }
 }
 
 /** @} */ // end of mapWallet
 
 void MaybeResendWalletTxs() {
     for (const std::shared_ptr<CWallet> &pwallet : GetWallets()) {
         pwallet->ResendWalletTransactions();
     }
 }
 
 /**
  * @defgroup Actions
  *
  * @{
  */
 CWallet::Balance CWallet::GetBalance(const int min_depth) const {
     Balance ret;
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
     for (const auto &entry : mapWallet) {
         const CWalletTx &wtx = entry.second;
         const bool is_trusted{wtx.IsTrusted(*locked_chain)};
         const int tx_depth{wtx.GetDepthInMainChain(*locked_chain)};
         const Amount tx_credit_mine{wtx.GetAvailableCredit(
             *locked_chain, /* fUseCache */ true, ISMINE_SPENDABLE)};
         const Amount tx_credit_watchonly{wtx.GetAvailableCredit(
             *locked_chain, /* fUseCache */ true, ISMINE_WATCH_ONLY)};
         if (is_trusted && tx_depth >= min_depth) {
             ret.m_mine_trusted += tx_credit_mine;
             ret.m_watchonly_trusted += tx_credit_watchonly;
         }
         if (!is_trusted && tx_depth == 0 && wtx.InMempool()) {
             ret.m_mine_untrusted_pending += tx_credit_mine;
             ret.m_watchonly_untrusted_pending += tx_credit_watchonly;
         }
         ret.m_mine_immature += wtx.GetImmatureCredit(*locked_chain);
         ret.m_watchonly_immature +=
             wtx.GetImmatureWatchOnlyCredit(*locked_chain);
     }
     return ret;
 }
 
 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_wallet);
 
     vCoins.clear();
     Amount nTotal = Amount::zero();
 
     const Consensus::Params params = Params().GetConsensus();
 
     for (const auto &entry : mapWallet) {
         const TxId &wtxid = entry.first;
         const CWalletTx &wtx = entry.second;
 
         CValidationState state;
         if (!locked_chain.contextualCheckTransactionForCurrentBlock(
                 params, *wtx.tx, state)) {
             continue;
         }
 
         if (wtx.IsImmatureCoinBase(locked_chain)) {
             continue;
         }
 
         int nDepth = wtx.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 && !wtx.InMempool()) {
             continue;
         }
 
         bool safeTx = wtx.IsTrusted(locked_chain);
 
         // Bitcoin-ABC: Removed check that prevents consideration of coins from
         // transactions that are replacing other transactions. This check based
         // on wtx.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 && wtx.mapValue.count("replaced_by_txid")) {
             safeTx = false;
         }
 
         if (fOnlySafe && !safeTx) {
             continue;
         }
 
         if (nDepth < nMinDepth || nDepth > nMaxDepth) {
             continue;
         }
 
         for (uint32_t i = 0; i < wtx.tx->vout.size(); i++) {
             if (wtx.tx->vout[i].nValue < nMinimumAmount ||
                 wtx.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(wtx.tx->vout[i]);
 
             if (mine == ISMINE_NO) {
                 continue;
             }
 
             bool solvable = IsSolvable(*this, wtx.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(&wtx, i, nDepth, spendable, solvable, safeTx,
                         (coinControl && coinControl->fAllowWatchOnly)));
 
             // Checks the sum amount of all UTXO's.
             if (nMinimumSumAmount != MAX_MONEY) {
                 nTotal += wtx.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_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);
 
         // 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 &wtx = it->second;
         // Clearly invalid input, fail.
         if (wtx.tx->vout.size() <= outpoint.GetN()) {
             return false;
         }
 
         // Just to calculate the marginal byte size
         nValueFromPresetInputs += wtx.tx->vout[outpoint.GetN()].nValue;
         setPresetCoins.insert(CInputCoin(wtx.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 &chain,
                                        interfaces::Chain::Lock &locked_chain) {
     if (chain.isInitialBlockDownload()) {
         return false;
     }
 
     // in seconds
     constexpr int64_t MAX_ANTI_FEE_SNIPING_TIP_AGE = 8 * 60 * 60;
     if (locked_chain.getBlockTime(*locked_chain.getHeight()) <
         (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 &chain,
                              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(chain, locked_chain)) {
         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 <= 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").translated;
             return false;
         }
 
         nValue += recipient.nAmount;
 
         if (recipient.fSubtractFeeFromAmount) {
             nSubtractFeeFromAmount++;
         }
     }
 
     if (vecSend.empty()) {
         strFailReason =
             _("Transaction must have at least one recipient").translated;
         return false;
     }
 
     CMutableTransaction txNew;
 
     txNew.nLockTime = GetLocktimeForNewTransaction(chain(), 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.")
                         .translated;
                 return false;
             }
             CPubKey vchPubKey;
             bool ret;
             ret = reservekey.GetReservedKey(vchPubKey, true);
             if (!ret) {
                 strFailReason =
                     _("Keypool ran out, please call keypoolrefill first")
                         .translated;
                 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);
 
         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, chain().relayDustFee())) {
                     if (recipient.fSubtractFeeFromAmount &&
                         nFeeRet > Amount::zero()) {
                         if (txout.nValue < Amount::zero()) {
                             strFailReason = _("The transaction amount is too "
                                               "small to pay the fee")
                                                 .translated;
                         } else {
                             strFailReason =
                                 _("The transaction amount is too small to "
                                   "send after the fee has been deducted")
                                     .translated;
                         }
                     } else {
                         strFailReason =
                             _("Transaction amount too small").translated;
                     }
 
                     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").translated;
                         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").translated;
                         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").translated;
                 return false;
             }
 
             Amount nFeeNeeded = GetMinimumFee(*this, nBytes, coinControl);
 
             // 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 < chain().relayMinFee().GetFee(nBytes)) {
                 strFailReason =
                     _("Transaction too large for fee policy").translated;
                 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);
                     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")
                         .translated;
                 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").translated;
                     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").translated;
             return false;
         }
     }
 
     if (gArgs.GetBoolArg("-walletrejectlongchains",
                          DEFAULT_WALLET_REJECT_LONG_CHAINS)) {
         // Lastly, ensure this tx will pass the mempool's chain limits
         if (!chain().checkChainLimits(tx)) {
             strFailReason =
                 _("Transaction has too long of a mempool chain").translated;
             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, 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, 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);
         }
     }
 
     return true;
 }
 
 DBErrors CWallet::LoadWallet(bool &fFirstRunRet) {
     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 &wtx = walletEntry.second;
 
         if (!wtx.IsTrusted(locked_chain)) {
             continue;
         }
 
         if (wtx.IsImmatureCoinBase(locked_chain)) {
             continue;
         }
 
         int nDepth = wtx.GetDepthInMainChain(locked_chain);
         if (nDepth < (wtx.IsFromMe(ISMINE_ALL) ? 0 : 1)) {
             continue;
         }
 
         for (uint32_t i = 0; i < wtx.tx->vout.size(); i++) {
             CTxDestination addr;
             if (!IsMine(wtx.tx->vout[i])) {
                 continue;
             }
 
             if (!ExtractDestination(wtx.tx->vout[i].scriptPubKey, addr)) {
                 continue;
             }
 
             Amount n = IsSpent(locked_chain, COutPoint(walletEntry.first, i))
                            ? Amount::zero()
                            : wtx.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 &wtx = walletEntry.second;
 
         if (wtx.tx->vin.size() > 0) {
             bool any_mine = false;
             // Group all input addresses with each other.
             for (const auto &txin : wtx.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 : wtx.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 : wtx.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
     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] = 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;
         if (Optional<int> height = locked_chain.getBlockHeight(wtx.hashBlock)) {
             // ... which are already in a block
             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, int>::iterator rit =
                         mapKeyFirstBlock.find(keyid);
                     if (rit != mapKeyFirstBlock.end() &&
                         *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] =
             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()) {
         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;
                 }
             }
 
             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)) {
         chain.initMessage(
             _("Zapping all transactions from wallet...").translated);
 
         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) {
             chain.initError(
                 strprintf(_("Error loading %s: Wallet corrupted").translated,
                           walletFile));
             return nullptr;
         }
     }
 
     chain.initMessage(_("Loading wallet...").translated);
 
     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) {
             chain.initError(
                 strprintf(_("Error loading %s: Wallet corrupted").translated,
                           walletFile));
             return nullptr;
         }
 
         if (nLoadWalletRet == DBErrors::NONCRITICAL_ERROR) {
             chain.initError(strprintf(
                 _("Error reading %s! All keys read correctly, but transaction "
                   "data or address book entries might be missing or incorrect.")
                     .translated,
                 walletFile));
         } else if (nLoadWalletRet == DBErrors::TOO_NEW) {
             chain.initError(strprintf(
                 _("Error loading %s: Wallet requires newer version of %s")
                     .translated,
                 walletFile, PACKAGE_NAME));
             return nullptr;
         } else if (nLoadWalletRet == DBErrors::NEED_REWRITE) {
             chain.initError(strprintf(
                 _("Wallet needed to be rewritten: restart %s to complete")
                     .translated,
                 PACKAGE_NAME));
             return nullptr;
         } else {
             chain.initError(
                 strprintf(_("Error loading %s").translated, 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()) {
             chain.initError(_("Cannot downgrade wallet").translated);
             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) {
             chain.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.")
                     .translated);
             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()) {
                 chain.initError(_("Unable to generate keys").translated);
                 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()) {
             chain.initError(_("Unable to generate initial keys").translated);
             return nullptr;
         }
 
         auto locked_chain = chain.lock();
         walletInstance->ChainStateFlushed(locked_chain->getTipLocator());
     } else if (wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS) {
         // Make it impossible to disable private keys after creation
         chain.initError(
             strprintf(_("Error loading %s: Private keys can only be "
                         "disabled during creation")
                           .translated,
                       walletFile));
         return nullptr;
     } else if (walletInstance->IsWalletFlagSet(
                    WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         LOCK(walletInstance->cs_KeyStore);
         if (!walletInstance->mapKeys.empty() ||
             !walletInstance->mapCryptedKeys.empty()) {
             chain.initWarning(
                 strprintf(_("Warning: Private keys detected in wallet "
                             "{%s} with disabled private keys")
                               .translated,
                           walletFile));
         }
     }
 
     if (gArgs.IsArgSet("-mintxfee")) {
         Amount n = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-mintxfee", ""), n) ||
             n == Amount::zero()) {
             chain.initError(
                 AmountErrMsg("mintxfee", gArgs.GetArg("-mintxfee", "")));
             return nullptr;
         }
         if (n > HIGH_TX_FEE_PER_KB) {
             chain.initWarning(
                 AmountHighWarn("-mintxfee") + " " +
                 _("This is the minimum transaction fee you pay on "
                   "every transaction.")
                     .translated);
         }
         walletInstance->m_min_fee = CFeeRate(n);
     }
 
     if (gArgs.IsArgSet("-fallbackfee")) {
         Amount nFeePerK = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-fallbackfee", ""), nFeePerK)) {
             chain.initError(strprintf(
                 _("Invalid amount for -fallbackfee=<amount>: '%s'").translated,
                 gArgs.GetArg("-fallbackfee", "")));
             return nullptr;
         }
         if (nFeePerK > HIGH_TX_FEE_PER_KB) {
             chain.initWarning(
                 AmountHighWarn("-fallbackfee") + " " +
                 _("This is the transaction fee you may pay when fee "
                   "estimates are not available.")
                     .translated);
         }
         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)) {
             chain.initError(
                 AmountErrMsg("paytxfee", gArgs.GetArg("-paytxfee", "")));
             return nullptr;
         }
         if (nFeePerK > HIGH_TX_FEE_PER_KB) {
             chain.initWarning(
                 AmountHighWarn("-paytxfee") + " " +
                 _("This is the transaction fee you will pay if you "
                   "send a transaction.")
                     .translated);
         }
         walletInstance->m_pay_tx_fee = CFeeRate(nFeePerK, 1000);
         if (walletInstance->m_pay_tx_fee < chain.relayMinFee()) {
             chain.initError(strprintf(
                 _("Invalid amount for -paytxfee=<amount>: '%s' "
                   "(must be at least %s)")
                     .translated,
                 gArgs.GetArg("-paytxfee", ""), chain.relayMinFee().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();
 
     auto locked_chain = chain.lock();
     LOCK(walletInstance->cs_wallet);
 
     int rescan_height = 0;
     if (!gArgs.GetBoolArg("-rescan", false)) {
         WalletBatch batch(*walletInstance->database);
         CBlockLocator locator;
         if (batch.ReadBestBlock(locator)) {
             if (const Optional<int> fork_height =
                     locked_chain->findLocatorFork(locator)) {
                 rescan_height = *fork_height;
             }
         }
     }
 
     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 (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 (chain.getPruneMode()) {
             int block_height = *tip_height;
             while (block_height > 0 &&
                    locked_chain->haveBlockOnDisk(block_height - 1) &&
                    rescan_height != block_height) {
                 --block_height;
             }
 
             if (rescan_height != block_height) {
                 chain.initError(
                     _("Prune: last wallet synchronisation goes beyond "
                       "pruned data. You need to -reindex (download the "
                       "whole blockchain again in case of pruned node)")
                         .translated);
                 return nullptr;
             }
         }
 
         chain.initMessage(_("Rescanning...").translated);
         walletInstance->WalletLogPrintf(
             "Rescanning last %i blocks (from block %i)...\n",
             *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)
         if (walletInstance->nTimeFirstKey) {
             if (Optional<int> first_block =
                     locked_chain->findFirstBlockWithTimeAndHeight(
                         walletInstance->nTimeFirstKey - TIMESTAMP_WINDOW,
-                        rescan_height)) {
+                        rescan_height, nullptr)) {
                 rescan_height = *first_block;
             }
         }
 
         nStart = GetTimeMillis();
         {
             WalletRescanReserver reserver(walletInstance.get());
             if (!reserver.reserve() ||
                 (ScanResult::SUCCESS !=
                  walletInstance
                      ->ScanForWalletTransactions(
                          locked_chain->getBlockHash(rescan_height), BlockHash(),
                          reserver, true /* update */)
                      .status)) {
                 chain.initError(
                     _("Failed to rescan the wallet during initialization")
                         .translated);
                 return nullptr;
             }
         }
         walletInstance->WalletLogPrintf("Rescan completed in %15dms\n",
                                         GetTimeMillis() - nStart);
         walletInstance->ChainStateFlushed(locked_chain->getTipLocator());
         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);
                 }
             }
         }
     }
 
     chain.loadWallet(interfaces::MakeWallet(walletInstance));
 
     // Register with the validation interface. It's ok to do this after rescan
     // since we're still holding locked_chain.
     walletInstance->handleNotifications();
 
     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::handleNotifications() {
     m_chain_notifications_handler = m_chain->handleNotifications(*this);
 }
 
 void CWallet::postInitProcess() {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     // Add wallet transactions that aren't already in a block to mempool.
     // Do this here as mempool requires genesis block to be loaded.
     ReacceptWalletTransactions(*locked_chain);
 
     // Update wallet transactions with current mempool transactions.
     chain().requestMempoolTransactions(*this);
 }
 
 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 BlockHash &block_hash, int posInBlock) {
     // Update the tx's hashBlock
     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;
     }
 
     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,
                                    CValidationState &state) {
     // 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 = locked_chain.submitToMemoryPool(
         ::GetConfig(), tx, pwallet->chain().maxTxFee(), state);
     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;
             chain().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.has_key_origin) {
         std::copy(meta.key_origin.fingerprint, meta.key_origin.fingerprint + 4,
                   info.fingerprint);
         info.path = meta.key_origin.path;
     } else {
         // Single pubkeys get the master fingerprint of themselves
         std::copy(keyID.begin(), keyID.begin() + 4, info.fingerprint);
     }
     return true;
 }
 
 bool CWallet::AddKeyOrigin(const CPubKey &pubkey, const KeyOriginInfo &info) {
     LOCK(cs_wallet);
     std::copy(info.fingerprint, info.fingerprint + 4,
               mapKeyMetadata[pubkey.GetID()].key_origin.fingerprint);
     mapKeyMetadata[pubkey.GetID()].key_origin.path = info.path;
     mapKeyMetadata[pubkey.GetID()].has_key_origin = true;
     mapKeyMetadata[pubkey.GetID()].hdKeypath = WriteHDKeypath(info.path);
     return WriteKeyMetadata(mapKeyMetadata[pubkey.GetID()], pubkey, true);
 }