diff --git a/.gitignore b/.gitignore
index 5c215945d..f00f2c3a6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,116 +1,115 @@
 *.tar.gz
 
 *.exe
 src/bitcoin
 src/bitcoind
 src/bitcoin-cli
 src/bitcoin-seeder
 src/bitcoin-tx
 src/test/test_bitcoin
 src/test/test_bitcoin_fuzzy
 src/qt/test/test_bitcoin-qt
-src/wallet.backup
 
 # autoreconf
 Makefile.in
 aclocal.m4
 autom4te.cache/
 build-aux/config.guess
 build-aux/config.sub
 build-aux/depcomp
 build-aux/install-sh
 build-aux/ltmain.sh
 build-aux/m4/libtool.m4
 build-aux/m4/lt~obsolete.m4
 build-aux/m4/ltoptions.m4
 build-aux/m4/ltsugar.m4
 build-aux/m4/ltversion.m4
 build-aux/missing
 build-aux/compile
 build-aux/test-driver
 config.log
 config.status
 configure
 libtool
 src/config/bitcoin-config.h
 src/config/bitcoin-config.h.in
 src/config/stamp-h1
 share/setup.nsi
 share/qt/Info.plist
 
 src/univalue/gen
 
 src/qt/*.moc
 src/qt/moc_*.cpp
 src/qt/forms/ui_*.h
 
 src/qt/test/moc*.cpp
 
 .deps
 .dirstamp
 .libs
 .*.swp
 *.*~*
 *.bak
 *.rej
 *.orig
 *.pyc
 *.o
 *.o-*
 *.patch
 *.a
 *.pb.cc
 *.pb.h
 
 *.log
 *.trs
 *.dmg
 
 *.json.h
 *.raw.h
 
 #libtool object files
 *.lo
 *.la
 
 # Compilation and Qt preprocessor part
 *.qm
 Makefile
 bitcoin-qt
 Bitcoin-Qt.app
 
 # Unit-tests
 Makefile.test
 bitcoin-qt_test
 
 # Resources cpp
 qrc_*.cpp
 
 # Mac specific
 .DS_Store
 build
 
 #lcov
 *.gcno
 *.gcda
 /*.info
 test_bitcoin.coverage/
 total.coverage/
 coverage_percent.txt
 
 #build tests
 linux-coverage-build
 linux-build
 win32-build
 test/config.ini
 test/cache/*
 
 !src/leveldb*/Makefile
 
 /doc/doxygen/
 
 libbitcoinconsensus.pc
 contrib/devtools/split-debug.sh
 
 # vagrant
 .vagrant
diff --git a/doc/release-notes.md b/doc/release-notes.md
index aba6a674c..917f4f221 100644
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -1,6 +1,8 @@
 Bitcoin ABC version 0.16.3 is now available from:
 
   <https://download.bitcoinabc.org/0.16.3/>
 
 This release includes the following features and fixes:
  - Add monolithactivationtime configuration in order to chose when the May, 15 hard fork activates. This value should not be changed in production, but it allows user to test the fork activation ahead of time.
+ - `dumpwallet` no longer allows overwriting files. This is a security measure
+   as well as prevents dangerous user mistakes.
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 3f28400a3..818beb8c7 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -1,1345 +1,1361 @@
 // 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 "base58.h"
 #include "chain.h"
 #include "config.h"
 #include "core_io.h"
 #include "dstencode.h"
 #include "init.h"
 #include "merkleblock.h"
 #include "rpc/server.h"
 #include "rpcwallet.h"
 #include "script/script.h"
 #include "script/standard.h"
 #include "sync.h"
 #include "util.h"
 #include "utiltime.h"
 #include "validation.h"
 #include "wallet.h"
 
 #include <boost/algorithm/string.hpp>
 #include <boost/date_time/posix_time/posix_time.hpp>
 
 #include <univalue.h>
 
 #include <cstdint>
 #include <fstream>
 #include <iostream>
 
 static std::string EncodeDumpTime(int64_t nTime) {
     return DateTimeStrFormat("%Y-%m-%dT%H:%M:%SZ", nTime);
 }
 
 static int64_t DecodeDumpTime(const std::string &str) {
     static const boost::posix_time::ptime epoch =
         boost::posix_time::from_time_t(0);
     static const std::locale loc(
         std::locale::classic(),
         new boost::posix_time::time_input_facet("%Y-%m-%dT%H:%M:%SZ"));
     std::istringstream iss(str);
     iss.imbue(loc);
     boost::posix_time::ptime ptime(boost::date_time::not_a_date_time);
     iss >> ptime;
     if (ptime.is_not_a_date_time()) return 0;
     return (ptime - epoch).total_seconds();
 }
 
 static std::string EncodeDumpString(const std::string &str) {
     std::stringstream ret;
     for (uint8_t c : str) {
         if (c <= 32 || c >= 128 || c == '%') {
             ret << '%' << HexStr(&c, &c + 1);
         } else {
             ret << c;
         }
     }
     return ret.str();
 }
 
 std::string DecodeDumpString(const std::string &str) {
     std::stringstream ret;
     for (unsigned int pos = 0; pos < str.length(); pos++) {
         uint8_t c = str[pos];
         if (c == '%' && pos + 2 < str.length()) {
             c = (((str[pos + 1] >> 6) * 9 + ((str[pos + 1] - '0') & 15)) << 4) |
                 ((str[pos + 2] >> 6) * 9 + ((str[pos + 2] - '0') & 15));
             pos += 2;
         }
         ret << c;
     }
     return ret.str();
 }
 
 UniValue importprivkey(const Config &config, const JSONRPCRequest &request) {
     CWallet *const pwallet = GetWalletForJSONRPCRequest(request);
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 || request.params.size() > 3)
         throw std::runtime_error(
             "importprivkey \"bitcoinprivkey\" ( \"label\" ) ( rescan )\n"
             "\nAdds a private key (as returned by dumpprivkey) to your "
             "wallet.\n"
             "\nArguments:\n"
             "1. \"bitcoinprivkey\"   (string, required) The private key (see "
             "dumpprivkey)\n"
             "2. \"label\"            (string, optional, default=\"\") An "
             "optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan "
             "the wallet for transactions\n"
             "\nNote: This call can take minutes to complete if rescan is "
             "true.\n"
             "\nExamples:\n"
             "\nDump a private key\n" +
             HelpExampleCli("dumpprivkey", "\"myaddress\"") +
             "\nImport the private key with rescan\n" +
             HelpExampleCli("importprivkey", "\"mykey\"") +
             "\nImport using a label and without rescan\n" +
             HelpExampleCli("importprivkey", "\"mykey\" \"testing\" false") +
             "\nImport using default blank label and without rescan\n" +
             HelpExampleCli("importprivkey", "\"mykey\" \"\" false") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("importprivkey", "\"mykey\", \"testing\", false"));
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
     std::string strSecret = request.params[0].get_str();
     std::string strLabel = "";
     if (request.params.size() > 1) {
         strLabel = request.params[1].get_str();
     }
 
     // Whether to perform rescan after import
     bool fRescan = true;
     if (request.params.size() > 2) {
         fRescan = request.params[2].get_bool();
     }
 
     if (fRescan && fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Rescan is disabled in pruned mode");
     }
 
     CBitcoinSecret vchSecret;
     bool fGood = vchSecret.SetString(strSecret);
 
     if (!fGood) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid private key encoding");
     }
 
     CKey key = vchSecret.GetKey();
     if (!key.IsValid()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Private key outside allowed range");
     }
 
     CPubKey pubkey = key.GetPubKey();
     assert(key.VerifyPubKey(pubkey));
     CKeyID vchAddress = pubkey.GetID();
     {
         pwallet->MarkDirty();
         pwallet->SetAddressBook(vchAddress, strLabel, "receive");
 
         // Don't throw error in case a key is already there
         if (pwallet->HaveKey(vchAddress)) {
             return NullUniValue;
         }
 
         pwallet->mapKeyMetadata[vchAddress].nCreateTime = 1;
 
         if (!pwallet->AddKeyPubKey(key, pubkey)) {
             throw JSONRPCError(RPC_WALLET_ERROR, "Error adding key to wallet");
         }
 
         // whenever a key is imported, we need to scan the whole chain
         pwallet->UpdateTimeFirstKey(1);
 
         if (fRescan) {
             pwallet->ScanForWalletTransactions(chainActive.Genesis(), true);
         }
     }
 
     return NullUniValue;
 }
 
 void ImportAddress(CWallet *, const CTxDestination &dest,
                    const std::string &strLabel);
 void ImportScript(CWallet *const pwallet, const CScript &script,
                   const std::string &strLabel, bool isRedeemScript) {
     if (!isRedeemScript && ::IsMine(*pwallet, script) == ISMINE_SPENDABLE) {
         throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already contains the "
                                              "private key for this address or "
                                              "script");
     }
 
     pwallet->MarkDirty();
 
     if (!pwallet->HaveWatchOnly(script) &&
         !pwallet->AddWatchOnly(script, 0 /* nCreateTime */)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
     }
 
     if (isRedeemScript) {
         if (!pwallet->HaveCScript(script) && !pwallet->AddCScript(script)) {
             throw JSONRPCError(RPC_WALLET_ERROR,
                                "Error adding p2sh redeemScript to wallet");
         }
         ImportAddress(pwallet, CScriptID(script), strLabel);
     } else {
         CTxDestination destination;
         if (ExtractDestination(script, destination)) {
             pwallet->SetAddressBook(destination, strLabel, "receive");
         }
     }
 }
 
 void ImportAddress(CWallet *const pwallet, const CTxDestination &dest,
                    const std::string &strLabel) {
     CScript script = GetScriptForDestination(dest);
     ImportScript(pwallet, script, strLabel, false);
     // add to address book or update label
     if (IsValidDestination(dest)) {
         pwallet->SetAddressBook(dest, strLabel, "receive");
     }
 }
 
 UniValue importaddress(const Config &config, const JSONRPCRequest &request) {
     CWallet *const pwallet = GetWalletForJSONRPCRequest(request);
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 4) {
         throw std::runtime_error(
             "importaddress \"address\" ( \"label\" rescan p2sh )\n"
             "\nAdds a script (in hex) or address that can be watched as if it "
             "were in your wallet but cannot be used to spend.\n"
             "\nArguments:\n"
             "1. \"script\"           (string, required) The hex-encoded script "
             "(or address)\n"
             "2. \"label\"            (string, optional, default=\"\") An "
             "optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan "
             "the wallet for transactions\n"
             "4. p2sh                 (boolean, optional, default=false) Add "
             "the P2SH version of the script as well\n"
             "\nNote: This call can take minutes to complete if rescan is "
             "true.\n"
             "If you have the full public key, you should call importpubkey "
             "instead of this.\n"
             "\nNote: If you import a non-standard raw script in hex form, "
             "outputs sending to it will be treated\n"
             "as change, and not show up in many RPCs.\n"
             "\nExamples:\n"
             "\nImport a script with rescan\n" +
             HelpExampleCli("importaddress", "\"myscript\"") +
             "\nImport using a label without rescan\n" +
             HelpExampleCli("importaddress", "\"myscript\" \"testing\" false") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("importaddress",
                            "\"myscript\", \"testing\", false"));
     }
 
     std::string strLabel = "";
     if (request.params.size() > 1) {
         strLabel = request.params[1].get_str();
     }
 
     // Whether to perform rescan after import
     bool fRescan = true;
     if (request.params.size() > 2) {
         fRescan = request.params[2].get_bool();
     }
 
     if (fRescan && fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Rescan is disabled in pruned mode");
     }
 
     // Whether to import a p2sh version, too
     bool fP2SH = false;
     if (request.params.size() > 3) {
         fP2SH = request.params[3].get_bool();
     }
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
     CTxDestination dest =
         DecodeDestination(request.params[0].get_str(), config.GetChainParams());
     if (IsValidDestination(dest)) {
         if (fP2SH) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Cannot use the p2sh flag with an address - use "
                                "a script instead");
         }
         ImportAddress(pwallet, dest, strLabel);
     } else if (IsHex(request.params[0].get_str())) {
         std::vector<uint8_t> data(ParseHex(request.params[0].get_str()));
         ImportScript(pwallet, CScript(data.begin(), data.end()), strLabel,
                      fP2SH);
     } else {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address or script");
     }
 
     if (fRescan) {
         pwallet->ScanForWalletTransactions(chainActive.Genesis(), true);
         pwallet->ReacceptWalletTransactions();
     }
 
     return NullUniValue;
 }
 
 UniValue importprunedfunds(const Config &config,
                            const JSONRPCRequest &request) {
     CWallet *const pwallet = GetWalletForJSONRPCRequest(request);
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 2) {
         throw std::runtime_error(
             "importprunedfunds\n"
             "\nImports funds without rescan. Corresponding address or script "
             "must previously be included in wallet. Aimed towards pruned "
             "wallets. The end-user is responsible to import additional "
             "transactions that subsequently spend the imported outputs or "
             "rescan after the point in the blockchain the transaction is "
             "included.\n"
             "\nArguments:\n"
             "1. \"rawtransaction\" (string, required) A raw transaction in hex "
             "funding an already-existing address in wallet\n"
             "2. \"txoutproof\"     (string, required) The hex output from "
             "gettxoutproof that contains the transaction\n");
     }
 
     CMutableTransaction tx;
     if (!DecodeHexTx(tx, request.params[0].get_str())) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
     }
     uint256 txid = tx.GetId();
     CWalletTx wtx(pwallet, MakeTransactionRef(std::move(tx)));
 
     CDataStream ssMB(ParseHexV(request.params[1], "proof"), SER_NETWORK,
                      PROTOCOL_VERSION);
     CMerkleBlock merkleBlock;
     ssMB >> merkleBlock;
 
     // Search partial merkle tree in proof for our transaction and index in
     // valid block
     std::vector<uint256> vMatch;
     std::vector<unsigned int> vIndex;
     unsigned int txnIndex = 0;
     if (merkleBlock.txn.ExtractMatches(vMatch, vIndex) ==
         merkleBlock.header.hashMerkleRoot) {
 
         LOCK(cs_main);
 
         if (!mapBlockIndex.count(merkleBlock.header.GetHash()) ||
             !chainActive.Contains(
                 mapBlockIndex[merkleBlock.header.GetHash()])) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Block not found in chain");
         }
 
         std::vector<uint256>::const_iterator it;
         if ((it = std::find(vMatch.begin(), vMatch.end(), txid)) ==
             vMatch.end()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Transaction given doesn't exist in proof");
         }
 
         txnIndex = vIndex[it - vMatch.begin()];
     } else {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Something wrong with merkleblock");
     }
 
     wtx.nIndex = txnIndex;
     wtx.hashBlock = merkleBlock.header.GetHash();
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
     if (pwallet->IsMine(wtx)) {
         pwallet->AddToWallet(wtx, false);
         return NullUniValue;
     }
 
     throw JSONRPCError(
         RPC_INVALID_ADDRESS_OR_KEY,
         "No addresses in wallet correspond to included transaction");
 }
 
 UniValue removeprunedfunds(const Config &config,
                            const JSONRPCRequest &request) {
     CWallet *const pwallet = GetWalletForJSONRPCRequest(request);
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "removeprunedfunds \"txid\"\n"
             "\nDeletes the specified transaction from the wallet. Meant for "
             "use with pruned wallets and as a companion to importprunedfunds. "
             "This will effect wallet balances.\n"
             "\nArguments:\n"
             "1. \"txid\"           (string, required) The hex-encoded id of "
             "the transaction you are deleting\n"
             "\nExamples:\n" +
             HelpExampleCli("removeprunedfunds", "\"a8d0c0184dde994a09ec054286f1"
                                                 "ce581bebf46446a512166eae762873"
                                                 "4ea0a5\"") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("removprunedfunds", "\"a8d0c0184dde994a09ec054286f1c"
                                                "e581bebf46446a512166eae7628734e"
                                                "a0a5\""));
     }
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
     uint256 hash;
     hash.SetHex(request.params[0].get_str());
     std::vector<uint256> vHash;
     vHash.push_back(hash);
     std::vector<uint256> vHashOut;
 
     if (pwallet->ZapSelectTx(vHash, vHashOut) != DB_LOAD_OK) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Could not properly delete the transaction.");
     }
 
     if (vHashOut.empty()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Transaction does not exist in wallet.");
     }
 
     return NullUniValue;
 }
 
 UniValue importpubkey(const Config &config, const JSONRPCRequest &request) {
     CWallet *const pwallet = GetWalletForJSONRPCRequest(request);
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 4) {
         throw std::runtime_error(
             "importpubkey \"pubkey\" ( \"label\" rescan )\n"
             "\nAdds a public key (in hex) that can be watched as if it were in "
             "your wallet but cannot be used to spend.\n"
             "\nArguments:\n"
             "1. \"pubkey\"           (string, required) The hex-encoded public "
             "key\n"
             "2. \"label\"            (string, optional, default=\"\") An "
             "optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan "
             "the wallet for transactions\n"
             "\nNote: This call can take minutes to complete if rescan is "
             "true.\n"
             "\nExamples:\n"
             "\nImport a public key with rescan\n" +
             HelpExampleCli("importpubkey", "\"mypubkey\"") +
             "\nImport using a label without rescan\n" +
             HelpExampleCli("importpubkey", "\"mypubkey\" \"testing\" false") +
             "\nAs a JSON-RPC call\n" +
             HelpExampleRpc("importpubkey", "\"mypubkey\", \"testing\", false"));
     }
 
     std::string strLabel = "";
     if (request.params.size() > 1) {
         strLabel = request.params[1].get_str();
     }
 
     // Whether to perform rescan after import
     bool fRescan = true;
     if (request.params.size() > 2) {
         fRescan = request.params[2].get_bool();
     }
 
     if (fRescan && fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Rescan is disabled in pruned mode");
     }
 
     if (!IsHex(request.params[0].get_str())) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Pubkey must be a hex string");
     }
 
     std::vector<uint8_t> data(ParseHex(request.params[0].get_str()));
     CPubKey pubKey(data.begin(), data.end());
     if (!pubKey.IsFullyValid()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Pubkey is not a valid public key");
     }
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
     ImportAddress(pwallet, pubKey.GetID(), strLabel);
     ImportScript(pwallet, GetScriptForRawPubKey(pubKey), strLabel, false);
 
     if (fRescan) {
         pwallet->ScanForWalletTransactions(chainActive.Genesis(), true);
         pwallet->ReacceptWalletTransactions();
     }
 
     return NullUniValue;
 }
 
 UniValue importwallet(const Config &config, const JSONRPCRequest &request) {
     CWallet *const pwallet = GetWalletForJSONRPCRequest(request);
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "importwallet \"filename\"\n"
             "\nImports keys from a wallet dump file (see dumpwallet).\n"
             "\nArguments:\n"
             "1. \"filename\"    (string, required) The wallet file\n"
             "\nExamples:\n"
             "\nDump the wallet\n" +
             HelpExampleCli("dumpwallet", "\"test\"") + "\nImport the wallet\n" +
             HelpExampleCli("importwallet", "\"test\"") +
             "\nImport using the json rpc call\n" +
             HelpExampleRpc("importwallet", "\"test\""));
     }
 
     if (fPruneMode) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Importing wallets is disabled in pruned mode");
     }
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
     std::ifstream file;
     file.open(request.params[0].get_str().c_str(),
               std::ios::in | std::ios::ate);
     if (!file.is_open()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Cannot open wallet dump file");
     }
 
     int64_t nTimeBegin = chainActive.Tip()->GetBlockTime();
 
     bool fGood = true;
 
     int64_t nFilesize = std::max((int64_t)1, (int64_t)file.tellg());
     file.seekg(0, file.beg);
 
     // show progress dialog in GUI
     pwallet->ShowProgress(_("Importing..."), 0);
     while (file.good()) {
         pwallet->ShowProgress(
             "", std::max(1, std::min(99, (int)(((double)file.tellg() /
                                                 (double)nFilesize) *
                                                100))));
         std::string line;
         std::getline(file, line);
         if (line.empty() || line[0] == '#') {
             continue;
         }
 
         std::vector<std::string> vstr;
         boost::split(vstr, line, boost::is_any_of(" "));
         if (vstr.size() < 2) {
             continue;
         }
         CBitcoinSecret vchSecret;
         if (!vchSecret.SetString(vstr[0])) {
             continue;
         }
         CKey key = vchSecret.GetKey();
         CPubKey pubkey = key.GetPubKey();
         assert(key.VerifyPubKey(pubkey));
         CKeyID keyid = pubkey.GetID();
         if (pwallet->HaveKey(keyid)) {
             LogPrintf("Skipping import of %s (key already present)\n",
                       EncodeDestination(keyid));
             continue;
         }
         int64_t nTime = DecodeDumpTime(vstr[1]);
         std::string strLabel;
         bool fLabel = true;
         for (unsigned int nStr = 2; nStr < vstr.size(); nStr++) {
             if (boost::algorithm::starts_with(vstr[nStr], "#")) {
                 break;
             }
             if (vstr[nStr] == "change=1") {
                 fLabel = false;
             }
             if (vstr[nStr] == "reserve=1") {
                 fLabel = false;
             }
             if (boost::algorithm::starts_with(vstr[nStr], "label=")) {
                 strLabel = DecodeDumpString(vstr[nStr].substr(6));
                 fLabel = true;
             }
         }
         LogPrintf("Importing %s...\n", EncodeDestination(keyid));
         if (!pwallet->AddKeyPubKey(key, pubkey)) {
             fGood = false;
             continue;
         }
         pwallet->mapKeyMetadata[keyid].nCreateTime = nTime;
         if (fLabel) {
             pwallet->SetAddressBook(keyid, strLabel, "receive");
         }
         nTimeBegin = std::min(nTimeBegin, nTime);
     }
     file.close();
 
     // hide progress dialog in GUI
     pwallet->ShowProgress("", 100);
     pwallet->UpdateTimeFirstKey(nTimeBegin);
 
     CBlockIndex *pindex =
         chainActive.FindEarliestAtLeast(nTimeBegin - TIMESTAMP_WINDOW);
 
     LogPrintf("Rescanning last %i blocks\n",
               chainActive.Height() - pindex->nHeight + 1);
     pwallet->ScanForWalletTransactions(pindex);
     pwallet->MarkDirty();
 
     if (!fGood) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Error adding some keys to wallet");
     }
 
     return NullUniValue;
 }
 
 UniValue dumpprivkey(const Config &config, const JSONRPCRequest &request) {
     CWallet *const pwallet = GetWalletForJSONRPCRequest(request);
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "dumpprivkey \"address\"\n"
             "\nReveals the private key corresponding to 'address'.\n"
             "Then the importprivkey can be used with this output\n"
             "\nArguments:\n"
             "1. \"address\"   (string, required) The bitcoin address for the "
             "private key\n"
             "\nResult:\n"
             "\"key\"                (string) The private key\n"
             "\nExamples:\n" +
             HelpExampleCli("dumpprivkey", "\"myaddress\"") +
             HelpExampleCli("importprivkey", "\"mykey\"") +
             HelpExampleRpc("dumpprivkey", "\"myaddress\""));
     }
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
     std::string strAddress = request.params[0].get_str();
     CTxDestination dest =
         DecodeDestination(strAddress, config.GetChainParams());
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Invalid Bitcoin address");
     }
     const CKeyID *keyID = boost::get<CKeyID>(&dest);
     if (!keyID) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to a key");
     }
     CKey vchSecret;
     if (!pwallet->GetKey(*keyID, vchSecret)) {
         throw JSONRPCError(RPC_WALLET_ERROR,
                            "Private key for address " + strAddress +
                                " is not known");
     }
     return CBitcoinSecret(vchSecret).ToString();
 }
 
 UniValue dumpwallet(const Config &config, const JSONRPCRequest &request) {
     CWallet *const pwallet = GetWalletForJSONRPCRequest(request);
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
 
     if (request.fHelp || request.params.size() != 1)
         throw std::runtime_error(
             "dumpwallet \"filename\"\n"
-            "\nDumps all wallet keys in a human-readable format.\n"
+            "\nDumps all wallet keys in a human-readable format to a "
+            "server-side file. This does not allow overwriting existing "
+            "files.\n"
             "\nArguments:\n"
             "1. \"filename\"    (string, required) The filename with path "
             "(either absolute or relative to bitcoind)\n"
             "\nResult:\n"
             "{                           (json object)\n"
             "  \"filename\" : {        (string) The filename with full "
             "absolute path\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("dumpwallet", "\"test\"") +
             HelpExampleRpc("dumpwallet", "\"test\""));
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
     EnsureWalletIsUnlocked(pwallet);
 
-    std::ofstream file;
     fs::path filepath = request.params[0].get_str();
     filepath = fs::absolute(filepath);
+
+    /**
+     * Prevent arbitrary files from being overwritten. There have been reports
+     * that users have overwritten wallet files this way:
+     * https://github.com/bitcoin/bitcoin/issues/9934
+     * It may also avoid other security issues.
+     */
+    if (fs::exists(filepath)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER,
+                           filepath.string() + " already exists. If you are "
+                                               "sure this is what you want, "
+                                               "move it out of the way first");
+    }
+
+    std::ofstream file;
     file.open(filepath.string().c_str());
     if (!file.is_open()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER,
                            "Cannot open wallet dump file");
     }
 
     std::map<CTxDestination, int64_t> mapKeyBirth;
     const std::map<CKeyID, int64_t> &mapKeyPool = pwallet->GetAllReserveKeys();
     pwallet->GetKeyBirthTimes(mapKeyBirth);
 
     // sort time/key pairs
     std::vector<std::pair<int64_t, CKeyID>> vKeyBirth;
     for (const auto &entry : mapKeyBirth) {
         if (const CKeyID *keyID = boost::get<CKeyID>(&entry.first)) {
             // set and test
             vKeyBirth.push_back(std::make_pair(entry.second, *keyID));
         }
     }
     mapKeyBirth.clear();
     std::sort(vKeyBirth.begin(), vKeyBirth.end());
 
     // produce output
     file << strprintf("# Wallet dump created by Bitcoin %s\n", CLIENT_BUILD);
     file << strprintf("# * Created on %s\n", EncodeDumpTime(GetTime()));
     file << strprintf("# * Best block at time of backup was %i (%s),\n",
                       chainActive.Height(),
                       chainActive.Tip()->GetBlockHash().ToString());
     file << strprintf("#   mined on %s\n",
                       EncodeDumpTime(chainActive.Tip()->GetBlockTime()));
     file << "\n";
 
     // add the base58check encoded extended master if the wallet uses HD
     CKeyID masterKeyID = pwallet->GetHDChain().masterKeyID;
     if (!masterKeyID.IsNull()) {
         CKey key;
         if (pwallet->GetKey(masterKeyID, key)) {
             CExtKey masterKey;
             masterKey.SetMaster(key.begin(), key.size());
 
             CBitcoinExtKey b58extkey;
             b58extkey.SetKey(masterKey);
 
             file << "# extended private masterkey: " << b58extkey.ToString()
                  << "\n\n";
         }
     }
     for (std::vector<std::pair<int64_t, CKeyID>>::const_iterator it =
              vKeyBirth.begin();
          it != vKeyBirth.end(); it++) {
         const CKeyID &keyid = it->second;
         std::string strTime = EncodeDumpTime(it->first);
         std::string strAddr = EncodeDestination(keyid);
         CKey key;
         if (pwallet->GetKey(keyid, key)) {
             file << strprintf("%s %s ", CBitcoinSecret(key).ToString(),
                               strTime);
             if (pwallet->mapAddressBook.count(keyid)) {
                 file << strprintf(
                     "label=%s",
                     EncodeDumpString(pwallet->mapAddressBook[keyid].name));
             } else if (keyid == masterKeyID) {
                 file << "hdmaster=1";
             } else if (mapKeyPool.count(keyid)) {
                 file << "reserve=1";
             } else if (pwallet->mapKeyMetadata[keyid].hdKeypath == "m") {
                 file << "inactivehdmaster=1";
             } else {
                 file << "change=1";
             }
             file << strprintf(
                 " # addr=%s%s\n", strAddr,
                 (pwallet->mapKeyMetadata[keyid].hdKeypath.size() > 0
                      ? " hdkeypath=" + pwallet->mapKeyMetadata[keyid].hdKeypath
                      : ""));
         }
     }
     file << "\n";
     file << "# End of dump\n";
     file.close();
 
     UniValue reply(UniValue::VOBJ);
     reply.push_back(Pair("filename", filepath.string()));
 
     return reply;
 }
 
 UniValue ProcessImport(CWallet *const pwallet, const UniValue &data,
                        const int64_t timestamp) {
     try {
         bool success = false;
 
         // Required fields.
         const UniValue &scriptPubKey = data["scriptPubKey"];
 
         // Should have script or JSON with "address".
         if (!(scriptPubKey.getType() == UniValue::VOBJ &&
               scriptPubKey.exists("address")) &&
             !(scriptPubKey.getType() == UniValue::VSTR)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid scriptPubKey");
         }
 
         // Optional fields.
         const std::string &strRedeemScript =
             data.exists("redeemscript") ? data["redeemscript"].get_str() : "";
         const UniValue &pubKeys =
             data.exists("pubkeys") ? data["pubkeys"].get_array() : UniValue();
         const UniValue &keys =
             data.exists("keys") ? data["keys"].get_array() : UniValue();
         const bool &internal =
             data.exists("internal") ? data["internal"].get_bool() : false;
         const bool &watchOnly =
             data.exists("watchonly") ? data["watchonly"].get_bool() : false;
         const std::string &label =
             data.exists("label") && !internal ? data["label"].get_str() : "";
 
         bool isScript = scriptPubKey.getType() == UniValue::VSTR;
         bool isP2SH = strRedeemScript.length() > 0;
         const std::string &output = isScript
                                         ? scriptPubKey.get_str()
                                         : scriptPubKey["address"].get_str();
 
         // Parse the output.
         CScript script;
         CTxDestination dest;
 
         if (!isScript) {
             dest = DecodeDestination(output, pwallet->chainParams);
             if (!IsValidDestination(dest)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Invalid address");
             }
             script = GetScriptForDestination(dest);
         } else {
             if (!IsHex(output)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Invalid scriptPubKey");
             }
 
             std::vector<uint8_t> vData(ParseHex(output));
             script = CScript(vData.begin(), vData.end());
         }
 
         // Watchonly and private keys
         if (watchOnly && keys.size()) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Incompatibility found between watchonly and keys");
         }
 
         // Internal + Label
         if (internal && data.exists("label")) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Incompatibility found between internal and label");
         }
 
         // Not having Internal + Script
         if (!internal && isScript) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Internal must be set for hex scriptPubKey");
         }
 
         // Keys / PubKeys size check.
         if (!isP2SH &&
             (keys.size() > 1 || pubKeys.size() > 1)) { // Address / scriptPubKey
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "More than private key given for one address");
         }
 
         // Invalid P2SH redeemScript
         if (isP2SH && !IsHex(strRedeemScript)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                "Invalid redeem script");
         }
 
         // Process. //
 
         // P2SH
         if (isP2SH) {
             // Import redeem script.
             std::vector<uint8_t> vData(ParseHex(strRedeemScript));
             CScript redeemScript = CScript(vData.begin(), vData.end());
 
             // Invalid P2SH address
             if (!script.IsPayToScriptHash()) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                    "Invalid P2SH address / script");
             }
 
             pwallet->MarkDirty();
 
             if (!pwallet->AddWatchOnly(redeemScript, timestamp)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding address to wallet");
             }
 
             if (!pwallet->HaveCScript(redeemScript) &&
                 !pwallet->AddCScript(redeemScript)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding p2sh redeemScript to wallet");
             }
 
             CTxDestination redeem_dest = CScriptID(redeemScript);
             CScript redeemDestination = GetScriptForDestination(redeem_dest);
 
             if (::IsMine(*pwallet, redeemDestination) == ISMINE_SPENDABLE) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "The wallet already contains the private "
                                    "key for this address or script");
             }
 
             pwallet->MarkDirty();
 
             if (!pwallet->AddWatchOnly(redeemDestination, timestamp)) {
                 throw JSONRPCError(RPC_WALLET_ERROR,
                                    "Error adding address to wallet");
             }
 
             // add to address book or update label
             if (IsValidDestination(dest)) {
                 pwallet->SetAddressBook(dest, label, "receive");
             }
 
             // Import private keys.
             if (keys.size()) {
                 for (size_t i = 0; i < keys.size(); i++) {
                     const std::string &privkey = keys[i].get_str();
 
                     CBitcoinSecret vchSecret;
                     bool fGood = vchSecret.SetString(privkey);
 
                     if (!fGood) {
                         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                            "Invalid private key encoding");
                     }
 
                     CKey key = vchSecret.GetKey();
 
                     if (!key.IsValid()) {
                         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                            "Private key outside allowed range");
                     }
 
                     CPubKey pubkey = key.GetPubKey();
                     assert(key.VerifyPubKey(pubkey));
 
                     CKeyID vchAddress = pubkey.GetID();
                     pwallet->MarkDirty();
                     pwallet->SetAddressBook(vchAddress, label, "receive");
 
                     if (pwallet->HaveKey(vchAddress)) {
                         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                            "Already have this key");
                     }
 
                     pwallet->mapKeyMetadata[vchAddress].nCreateTime = timestamp;
 
                     if (!pwallet->AddKeyPubKey(key, pubkey)) {
                         throw JSONRPCError(RPC_WALLET_ERROR,
                                            "Error adding key to wallet");
                     }
 
                     pwallet->UpdateTimeFirstKey(timestamp);
                 }
             }
 
             success = true;
         } else {
             // Import public keys.
             if (pubKeys.size() && keys.size() == 0) {
                 const std::string &strPubKey = pubKeys[0].get_str();
 
                 if (!IsHex(strPubKey)) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Pubkey must be a hex string");
                 }
 
                 std::vector<uint8_t> vData(ParseHex(strPubKey));
                 CPubKey pubKey(vData.begin(), vData.end());
 
                 if (!pubKey.IsFullyValid()) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Pubkey is not a valid public key");
                 }
 
                 CTxDestination pubkey_dest = pubKey.GetID();
 
                 // Consistency check.
                 if (!isScript && !(pubkey_dest == dest)) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Consistency check failed");
                 }
 
                 // Consistency check.
                 if (isScript) {
                     CTxDestination destination;
 
                     if (ExtractDestination(script, destination)) {
                         if (!(destination == pubkey_dest)) {
                             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                                "Consistency check failed");
                         }
                     }
                 }
 
                 CScript pubKeyScript = GetScriptForDestination(pubkey_dest);
 
                 if (::IsMine(*pwallet, pubKeyScript) == ISMINE_SPENDABLE) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->MarkDirty();
 
                 if (!pwallet->AddWatchOnly(pubKeyScript, timestamp)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding address to wallet");
                 }
 
                 // add to address book or update label
                 if (IsValidDestination(pubkey_dest)) {
                     pwallet->SetAddressBook(pubkey_dest, label, "receive");
                 }
 
                 // TODO Is this necessary?
                 CScript scriptRawPubKey = GetScriptForRawPubKey(pubKey);
 
                 if (::IsMine(*pwallet, scriptRawPubKey) == ISMINE_SPENDABLE) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->MarkDirty();
 
                 if (!pwallet->AddWatchOnly(scriptRawPubKey, timestamp)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding address to wallet");
                 }
 
                 success = true;
             }
 
             // Import private keys.
             if (keys.size()) {
                 const std::string &strPrivkey = keys[0].get_str();
 
                 // Checks.
                 CBitcoinSecret vchSecret;
                 bool fGood = vchSecret.SetString(strPrivkey);
 
                 if (!fGood) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Invalid private key encoding");
                 }
 
                 CKey key = vchSecret.GetKey();
                 if (!key.IsValid()) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Private key outside allowed range");
                 }
 
                 CPubKey pubKey = key.GetPubKey();
                 assert(key.VerifyPubKey(pubKey));
 
                 CTxDestination pubkey_dest = pubKey.GetID();
 
                 // Consistency check.
                 if (!isScript && !(pubkey_dest == dest)) {
                     throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                        "Consistency check failed");
                 }
 
                 // Consistency check.
                 if (isScript) {
                     CTxDestination destination;
 
                     if (ExtractDestination(script, destination)) {
                         if (!(destination == pubkey_dest)) {
                             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                                                "Consistency check failed");
                         }
                     }
                 }
 
                 CKeyID vchAddress = pubKey.GetID();
                 pwallet->MarkDirty();
                 pwallet->SetAddressBook(vchAddress, label, "receive");
 
                 if (pwallet->HaveKey(vchAddress)) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->mapKeyMetadata[vchAddress].nCreateTime = timestamp;
 
                 if (!pwallet->AddKeyPubKey(key, pubKey)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding key to wallet");
                 }
 
                 pwallet->UpdateTimeFirstKey(timestamp);
 
                 success = true;
             }
 
             // Import scriptPubKey only.
             if (pubKeys.size() == 0 && keys.size() == 0) {
                 if (::IsMine(*pwallet, script) == ISMINE_SPENDABLE) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already "
                                                          "contains the private "
                                                          "key for this address "
                                                          "or script");
                 }
 
                 pwallet->MarkDirty();
 
                 if (!pwallet->AddWatchOnly(script, timestamp)) {
                     throw JSONRPCError(RPC_WALLET_ERROR,
                                        "Error adding address to wallet");
                 }
 
                 if (scriptPubKey.getType() == UniValue::VOBJ) {
                     // add to address book or update label
                     if (IsValidDestination(dest)) {
                         pwallet->SetAddressBook(dest, label, "receive");
                     }
                 }
 
                 success = true;
             }
         }
 
         UniValue result = UniValue(UniValue::VOBJ);
         result.pushKV("success", UniValue(success));
         return result;
     } catch (const UniValue &e) {
         UniValue result = UniValue(UniValue::VOBJ);
         result.pushKV("success", UniValue(false));
         result.pushKV("error", e);
         return result;
     } catch (...) {
         UniValue result = UniValue(UniValue::VOBJ);
         result.pushKV("success", UniValue(false));
         result.pushKV("error",
                       JSONRPCError(RPC_MISC_ERROR, "Missing required fields"));
         return result;
     }
 }
 
 int64_t GetImportTimestamp(const UniValue &data, int64_t now) {
     if (data.exists("timestamp")) {
         const UniValue &timestamp = data["timestamp"];
         if (timestamp.isNum()) {
             return timestamp.get_int64();
         } else if (timestamp.isStr() && timestamp.get_str() == "now") {
             return now;
         }
         throw JSONRPCError(RPC_TYPE_ERROR,
                            strprintf("Expected number or \"now\" timestamp "
                                      "value for key. got type %s",
                                      uvTypeName(timestamp.type())));
     }
     throw JSONRPCError(RPC_TYPE_ERROR,
                        "Missing required timestamp field for key");
 }
 
 UniValue importmulti(const Config &config, const JSONRPCRequest &mainRequest) {
     CWallet *const pwallet = GetWalletForJSONRPCRequest(mainRequest);
     if (!EnsureWalletIsAvailable(pwallet, mainRequest.fHelp)) {
         return NullUniValue;
     }
 
     // clang-format off
     if (mainRequest.fHelp || mainRequest.params.size() < 1 || mainRequest.params.size() > 2) {
         throw std::runtime_error(
             "importmulti \"requests\" \"options\"\n\n"
             "Import addresses/scripts (with private or public keys, redeem script (P2SH)), rescanning all addresses in one-shot-only (rescan can be disabled via options).\n\n"
             "Arguments:\n"
             "1. requests     (array, required) Data to be imported\n"
             "  [     (array of json objects)\n"
             "    {\n"
             "      \"scriptPubKey\": \"<script>\" | { \"address\":\"<address>\" }, (string / json, required) Type of scriptPubKey (string for script, json for address)\n"
             "      \"timestamp\": timestamp | \"now\"                        , (integer / string, required) Creation time of the key in seconds since epoch (Jan 1 1970 GMT),\n"
             "                                                              or the string \"now\" to substitute the current synced blockchain time. The timestamp of the oldest\n"
             "                                                              key will determine how far back blockchain rescans need to begin for missing wallet transactions.\n"
             "                                                              \"now\" can be specified to bypass scanning, for keys which are known to never have been used, and\n"
             "                                                              0 can be specified to scan the entire blockchain. Blocks up to 2 hours before the earliest key\n"
             "                                                              creation time of all keys being imported by the importmulti call will be scanned.\n"
             "      \"redeemscript\": \"<script>\"                            , (string, optional) Allowed only if the scriptPubKey is a P2SH address or a P2SH scriptPubKey\n"
             "      \"pubkeys\": [\"<pubKey>\", ... ]                         , (array, optional) Array of strings giving pubkeys that must occur in the output or redeemscript\n"
             "      \"keys\": [\"<key>\", ... ]                               , (array, optional) Array of strings giving private keys whose corresponding public keys must occur in the output or redeemscript\n"
             "      \"internal\": <true>                                    , (boolean, optional, default: false) Stating whether matching outputs should be be treated as not incoming payments\n"
             "      \"watchonly\": <true>                                   , (boolean, optional, default: false) Stating whether matching outputs should be considered watched even when they're not spendable, only allowed if keys are empty\n"
             "      \"label\": <label>                                      , (string, optional, default: '') Label to assign to the address (aka account name, for now), only allowed with internal=false\n"
             "    }\n"
             "  ,...\n"
             "  ]\n"
             "2. options                 (json, optional)\n"
             "  {\n"
             "     \"rescan\": <false>,         (boolean, optional, default: true) Stating if should rescan the blockchain after all imports\n"
             "  }\n"
             "\nExamples:\n" +
             HelpExampleCli("importmulti", "'[{ \"scriptPubKey\": { \"address\": \"<my address>\" }, \"timestamp\":1455191478 }, "
                                           "{ \"scriptPubKey\": { \"address\": \"<my 2nd address>\" }, \"label\": \"example 2\", \"timestamp\": 1455191480 }]'") +
             HelpExampleCli("importmulti", "'[{ \"scriptPubKey\": { \"address\": \"<my address>\" }, \"timestamp\":1455191478 }]' '{ \"rescan\": false}'") +
 
             "\nResponse is an array with the same size as the input that has the execution result :\n"
             "  [{ \"success\": true } , { \"success\": false, \"error\": { \"code\": -1, \"message\": \"Internal Server Error\"} }, ... ]\n");
     }
 
     // clang-format on
 
     RPCTypeCheck(mainRequest.params, {UniValue::VARR, UniValue::VOBJ});
 
     const UniValue &requests = mainRequest.params[0];
 
     // Default options
     bool fRescan = true;
 
     if (mainRequest.params.size() > 1) {
         const UniValue &options = mainRequest.params[1];
 
         if (options.exists("rescan")) {
             fRescan = options["rescan"].get_bool();
         }
     }
 
     LOCK2(cs_main, pwallet->cs_wallet);
     EnsureWalletIsUnlocked(pwallet);
 
     // Verify all timestamps are present before importing any keys.
     const int64_t now =
         chainActive.Tip() ? chainActive.Tip()->GetMedianTimePast() : 0;
     for (const UniValue &data : requests.getValues()) {
         GetImportTimestamp(data, now);
     }
 
     bool fRunScan = false;
     const int64_t minimumTimestamp = 1;
     int64_t nLowestTimestamp = 0;
 
     if (fRescan && chainActive.Tip()) {
         nLowestTimestamp = chainActive.Tip()->GetBlockTime();
     } else {
         fRescan = false;
     }
 
     UniValue response(UniValue::VARR);
 
     for (const UniValue &data : requests.getValues()) {
         const int64_t timestamp =
             std::max(GetImportTimestamp(data, now), minimumTimestamp);
         const UniValue result = ProcessImport(pwallet, data, timestamp);
         response.push_back(result);
 
         if (!fRescan) {
             continue;
         }
 
         // If at least one request was successful then allow rescan.
         if (result["success"].get_bool()) {
             fRunScan = true;
         }
 
         // Get the lowest timestamp.
         if (timestamp < nLowestTimestamp) {
             nLowestTimestamp = timestamp;
         }
     }
 
     if (fRescan && fRunScan && requests.size()) {
         CBlockIndex *pindex =
             nLowestTimestamp > minimumTimestamp
                 ? chainActive.FindEarliestAtLeast(
                       std::max<int64_t>(nLowestTimestamp - TIMESTAMP_WINDOW, 0))
                 : chainActive.Genesis();
         CBlockIndex *scannedRange = nullptr;
         if (pindex) {
             scannedRange = pwallet->ScanForWalletTransactions(pindex, true);
             pwallet->ReacceptWalletTransactions();
         }
 
         if (!scannedRange || scannedRange->nHeight > pindex->nHeight) {
             std::vector<UniValue> results = response.getValues();
             response.clear();
             response.setArray();
             size_t i = 0;
             for (const UniValue &request : requests.getValues()) {
                 // If key creation date is within the successfully scanned
                 // range, or if the import result already has an error set, let
                 // the result stand unmodified. Otherwise replace the result
                 // with an error message.
                 if (GetImportTimestamp(request, now) - TIMESTAMP_WINDOW >=
                         scannedRange->GetBlockTimeMax() ||
                     results.at(i).exists("error")) {
                     response.push_back(results.at(i));
                 } else {
                     UniValue result = UniValue(UniValue::VOBJ);
                     result.pushKV("success", UniValue(false));
                     result.pushKV(
                         "error",
                         JSONRPCError(
                             RPC_MISC_ERROR,
                             strprintf("Failed to rescan before time %d, "
                                       "transactions may be missing.",
                                       scannedRange->GetBlockTimeMax())));
                     response.push_back(std::move(result));
                 }
                 ++i;
             }
         }
     }
 
     return response;
 }
 
 // clang-format off
 static const CRPCCommand commands[] = {
     //  category            name                        actor (function)          okSafeMode
     //  ------------------- ------------------------    ----------------------    ----------
     { "wallet",             "dumpprivkey",              dumpprivkey,              true,   {"address"}  },
     { "wallet",             "dumpwallet",               dumpwallet,               true,   {"filename"} },
     { "wallet",             "importmulti",              importmulti,              true,   {"requests","options"} },
     { "wallet",             "importprivkey",            importprivkey,            true,   {"privkey","label","rescan"} },
     { "wallet",             "importwallet",             importwallet,             true,   {"filename"} },
     { "wallet",             "importaddress",            importaddress,            true,   {"address","label","rescan","p2sh"} },
     { "wallet",             "importprunedfunds",        importprunedfunds,        true,   {"rawtransaction","txoutproof"} },
     { "wallet",             "importpubkey",             importpubkey,             true,   {"pubkey","label","rescan"} },
     { "wallet",             "removeprunedfunds",        removeprunedfunds,        true,   {"txid"} },
 };
 // clang-format on
 
 void RegisterDumpRPCCommands(CRPCTable &t) {
     if (gArgs.GetBoolArg("-disablewallet", false)) {
         return;
     }
 
     for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++) {
         t.appendCommand(commands[vcidx].name, &commands[vcidx]);
     }
 }
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 1d5325fcb..856d1eb9b 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -1,678 +1,678 @@
 // Copyright (c) 2012-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "wallet/wallet.h"
 
 #include "chainparams.h"
 #include "config.h"
 #include "rpc/server.h"
 #include "test/test_bitcoin.h"
 #include "validation.h"
 #include "wallet/rpcdump.h"
 #include "wallet/test/wallet_test_fixture.h"
 
 #include <boost/test/unit_test.hpp>
 
 #include <univalue.h>
 
 #include <cstdint>
 #include <set>
 #include <utility>
 #include <vector>
 
 extern CWallet *pwalletMain;
 
 // how many times to run all the tests to have a chance to catch errors that
 // only show up with particular random shuffles
 #define RUN_TESTS 100
 
 // some tests fail 1% of the time due to bad luck. We repeat those tests this
 // many times and only complain if all iterations of the test fail.
 #define RANDOM_REPEATS 5
 
 std::vector<std::unique_ptr<CWalletTx>> wtxn;
 
 typedef std::set<std::pair<const CWalletTx *, unsigned int>> CoinSet;
 
 BOOST_FIXTURE_TEST_SUITE(wallet_tests, WalletTestingSetup)
 
 // Critical section is used to prevent concurrent execution of
 // tests in this fixture
 static CCriticalSection walletCriticalSection;
 
 static std::vector<COutput> vCoins;
 
 static void add_coin(const CWallet &wallet, const Amount nValue,
                      int nAge = 6 * 24, bool fIsFromMe = false,
                      int nInput = 0) {
     static int nextLockTime = 0;
     CMutableTransaction tx;
     tx.nLockTime = nextLockTime++; // so all transactions get different hashes
     tx.vout.resize(nInput + 1);
     tx.vout[nInput].nValue = nValue;
     if (fIsFromMe) {
         // IsFromMe() returns (GetDebit() > 0), and GetDebit() is 0 if
         // vin.empty(), so stop vin being empty, and cache a non-zero Debit to
         // fake out IsFromMe()
         tx.vin.resize(1);
     }
     std::unique_ptr<CWalletTx> wtx(
         new CWalletTx(&wallet, MakeTransactionRef(std::move(tx))));
     if (fIsFromMe) {
         wtx->fDebitCached = true;
         wtx->nDebitCached = Amount(1);
     }
     COutput output(wtx.get(), nInput, nAge, true /* spendable */,
                    true /* solvable */, true /* safe */);
     vCoins.push_back(output);
     wtxn.emplace_back(std::move(wtx));
 }
 
 static void empty_wallet(void) {
     vCoins.clear();
     wtxn.clear();
 }
 
 static bool equal_sets(CoinSet a, CoinSet b) {
     std::pair<CoinSet::iterator, CoinSet::iterator> ret =
         mismatch(a.begin(), a.end(), b.begin());
     return ret.first == a.end() && ret.second == b.end();
 }
 
 BOOST_AUTO_TEST_CASE(coin_selection_tests) {
     CoinSet setCoinsRet, setCoinsRet2;
     Amount nValueRet;
 
     const CWallet wallet(Params());
     LOCK(walletCriticalSection);
 
     // test multiple times to allow for differences in the shuffle order
     for (int i = 0; i < RUN_TESTS; i++) {
         empty_wallet();
 
         // with an empty wallet we can't even pay one cent
         BOOST_CHECK(!wallet.SelectCoinsMinConf(1 * CENT, 1, 6, 0, vCoins,
                                                setCoinsRet, nValueRet));
         // add a new 1 cent coin
         add_coin(wallet, 1 * CENT, 4);
 
         // with a new 1 cent coin, we still can't find a mature 1 cent
         BOOST_CHECK(!wallet.SelectCoinsMinConf(1 * CENT, 1, 6, 0, vCoins,
                                                setCoinsRet, nValueRet));
 
         // but we can find a new 1 cent
         BOOST_CHECK(wallet.SelectCoinsMinConf(1 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 1 * CENT);
         // add a mature 2 cent coin
         add_coin(wallet, 2 * CENT);
 
         // we can't make 3 cents of mature coins
         BOOST_CHECK(!wallet.SelectCoinsMinConf(3 * CENT, 1, 6, 0, vCoins,
                                                setCoinsRet, nValueRet));
 
         // we can make 3 cents of new  coins
         BOOST_CHECK(wallet.SelectCoinsMinConf(3 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 3 * CENT);
 
         // add a mature 5 cent coin,
         add_coin(wallet, 5 * CENT);
         // a new 10 cent coin sent from one of our own addresses
         add_coin(wallet, 10 * CENT, 3, true);
         // and a mature 20 cent coin
         add_coin(wallet, 20 * CENT);
 
         // now we have new: 1+10=11 (of which 10 was self-sent), and mature:
         // 2+5+20=27.  total = 38
 
         // we can't make 38 cents only if we disallow new coins:
         BOOST_CHECK(!wallet.SelectCoinsMinConf(38 * CENT, 1, 6, 0, vCoins,
                                                setCoinsRet, nValueRet));
         // we can't even make 37 cents if we don't allow new coins even if
         // they're from us
         BOOST_CHECK(!wallet.SelectCoinsMinConf(38 * CENT, 6, 6, 0, vCoins,
                                                setCoinsRet, nValueRet));
         // but we can make 37 cents if we accept new coins from ourself
         BOOST_CHECK(wallet.SelectCoinsMinConf(37 * CENT, 1, 6, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 37 * CENT);
         // and we can make 38 cents if we accept all new coins
         BOOST_CHECK(wallet.SelectCoinsMinConf(38 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 38 * CENT);
 
         // try making 34 cents from 1,2,5,10,20 - we can't do it exactly
         BOOST_CHECK(wallet.SelectCoinsMinConf(34 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // but 35 cents is closest
         BOOST_CHECK_EQUAL(nValueRet, 35 * CENT);
         // the best should be 20+10+5.  it's incredibly unlikely the 1 or 2 got
         // included (but possible)
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
 
         // when we try making 7 cents, the smaller coins (1,2,5) are enough.  We
         // should see just 2+5
         BOOST_CHECK(wallet.SelectCoinsMinConf(7 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 7 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
 
         // when we try making 8 cents, the smaller coins (1,2,5) are exactly
         // enough.
         BOOST_CHECK(wallet.SelectCoinsMinConf(8 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK(nValueRet == 8 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
 
         // when we try making 9 cents, no subset of smaller coins is enough, and
         // we get the next bigger coin (10)
         BOOST_CHECK(wallet.SelectCoinsMinConf(9 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 10 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
         // now clear out the wallet and start again to test choosing between
         // subsets of smaller coins and the next biggest coin
         empty_wallet();
 
         add_coin(wallet, 6 * CENT);
         add_coin(wallet, 7 * CENT);
         add_coin(wallet, 8 * CENT);
         add_coin(wallet, 20 * CENT);
         // now we have 6+7+8+20+30 = 71 cents total
         add_coin(wallet, 30 * CENT);
 
         // check that we have 71 and not 72
         BOOST_CHECK(wallet.SelectCoinsMinConf(71 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK(!wallet.SelectCoinsMinConf(72 * CENT, 1, 1, 0, vCoins,
                                                setCoinsRet, nValueRet));
 
         // now try making 16 cents.  the best smaller coins can do is 6+7+8 =
         // 21; not as good at the next biggest coin, 20
         BOOST_CHECK(wallet.SelectCoinsMinConf(16 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we should get 20 in one coin
         BOOST_CHECK_EQUAL(nValueRet, 20 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
         // now we have 5+6+7+8+20+30 = 75 cents total
         add_coin(wallet, 5 * CENT);
 
         // now if we try making 16 cents again, the smaller coins can make 5+6+7
         // = 18 cents, better than the next biggest coin, 20
         BOOST_CHECK(wallet.SelectCoinsMinConf(16 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we should get 18 in 3 coins
         BOOST_CHECK_EQUAL(nValueRet, 18 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
 
         // now we have 5+6+7+8+18+20+30
         add_coin(wallet, 18 * CENT);
 
         // and now if we try making 16 cents again, the smaller coins can make
         // 5+6+7 = 18 cents, the same as the next biggest coin, 18
         BOOST_CHECK(wallet.SelectCoinsMinConf(16 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we should get 18 in 1 coin
         BOOST_CHECK_EQUAL(nValueRet, 18 * CENT);
         // because in the event of a tie, the biggest coin wins
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
         // now try making 11 cents.  we should get 5+6
         BOOST_CHECK(wallet.SelectCoinsMinConf(11 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 11 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
 
         // check that the smallest bigger coin is used
         add_coin(wallet, 1 * COIN);
         add_coin(wallet, 2 * COIN);
         add_coin(wallet, 3 * COIN);
         // now we have 5+6+7+8+18+20+30+100+200+300+400 = 1094 cents
         add_coin(wallet, 4 * COIN);
         BOOST_CHECK(wallet.SelectCoinsMinConf(95 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we should get 1 BCH in 1 coin
         BOOST_CHECK_EQUAL(nValueRet, 1 * COIN);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
         BOOST_CHECK(wallet.SelectCoinsMinConf(195 * CENT, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we should get 2 BCH in 1 coin
         BOOST_CHECK_EQUAL(nValueRet, 2 * COIN);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
         // empty the wallet and start again, now with fractions of a cent, to
         // test small change avoidance
 
         empty_wallet();
         add_coin(wallet, 1 * MIN_CHANGE / 10);
         add_coin(wallet, 2 * MIN_CHANGE / 10);
         add_coin(wallet, 3 * MIN_CHANGE / 10);
         add_coin(wallet, 4 * MIN_CHANGE / 10);
         add_coin(wallet, 5 * MIN_CHANGE / 10);
 
         // try making 1 * MIN_CHANGE from the 1.5 * MIN_CHANGE we'll get change
         // smaller than MIN_CHANGE whatever happens, so can expect MIN_CHANGE
         // exactly
         BOOST_CHECK(wallet.SelectCoinsMinConf(MIN_CHANGE, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, MIN_CHANGE);
 
         // but if we add a bigger coin, small change is avoided
         add_coin(wallet, 1111 * MIN_CHANGE);
 
         // try making 1 from 0.1 + 0.2 + 0.3 + 0.4 + 0.5 + 1111 = 1112.5
         BOOST_CHECK(wallet.SelectCoinsMinConf(1 * MIN_CHANGE, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we should get the exact amount
         BOOST_CHECK_EQUAL(nValueRet, 1 * MIN_CHANGE);
 
         // if we add more small coins:
         add_coin(wallet, 6 * MIN_CHANGE / 10);
         add_coin(wallet, 7 * MIN_CHANGE / 10);
 
         // and try again to make 1.0 * MIN_CHANGE
         BOOST_CHECK(wallet.SelectCoinsMinConf(1 * MIN_CHANGE, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we should get the exact amount
         BOOST_CHECK_EQUAL(nValueRet, 1 * MIN_CHANGE);
 
         // run the 'mtgox' test (see
         // http://blockexplorer.com/tx/29a3efd3ef04f9153d47a990bd7b048a4b2d213daaa5fb8ed670fb85f13bdbcf)
         // they tried to consolidate 10 50k coins into one 500k coin, and ended
         // up with 50k in change
         empty_wallet();
         for (int j = 0; j < 20; j++) {
             add_coin(wallet, 50000 * COIN);
         }
 
         BOOST_CHECK(wallet.SelectCoinsMinConf(500000 * COIN, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we should get the exact amount
         BOOST_CHECK_EQUAL(nValueRet, 500000 * COIN);
         // in ten coins
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 10U);
 
         // if there's not enough in the smaller coins to make at least 1 *
         // MIN_CHANGE change (0.5+0.6+0.7 < 1.0+1.0), we need to try finding an
         // exact subset anyway
 
         // sometimes it will fail, and so we use the next biggest coin:
         empty_wallet();
         add_coin(wallet, 5 * MIN_CHANGE / 10);
         add_coin(wallet, 6 * MIN_CHANGE / 10);
         add_coin(wallet, 7 * MIN_CHANGE / 10);
         add_coin(wallet, 1111 * MIN_CHANGE);
         BOOST_CHECK(wallet.SelectCoinsMinConf(1 * MIN_CHANGE, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we get the bigger coin
         BOOST_CHECK_EQUAL(nValueRet, 1111 * MIN_CHANGE);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
         // but sometimes it's possible, and we use an exact subset (0.4 + 0.6 =
         // 1.0)
         empty_wallet();
         add_coin(wallet, 4 * MIN_CHANGE / 10);
         add_coin(wallet, 6 * MIN_CHANGE / 10);
         add_coin(wallet, 8 * MIN_CHANGE / 10);
         add_coin(wallet, 1111 * MIN_CHANGE);
         BOOST_CHECK(wallet.SelectCoinsMinConf(MIN_CHANGE, 1, 1, 0, vCoins,
                                               setCoinsRet, nValueRet));
         // we should get the exact amount
         BOOST_CHECK_EQUAL(nValueRet, MIN_CHANGE);
         // in two coins 0.4+0.6
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
 
         // test avoiding small change
         empty_wallet();
         add_coin(wallet, 5 * MIN_CHANGE / 100);
         add_coin(wallet, 1 * MIN_CHANGE);
         add_coin(wallet, 100 * MIN_CHANGE);
 
         // trying to make 100.01 from these three coins
         BOOST_CHECK(wallet.SelectCoinsMinConf(10001 * MIN_CHANGE / 100, 1, 1, 0,
                                               vCoins, setCoinsRet, nValueRet));
         // we should get all coins
         BOOST_CHECK_EQUAL(nValueRet, 10105 * MIN_CHANGE / 100);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
 
         // but if we try to make 99.9, we should take the bigger of the two
         // small coins to avoid small change
         BOOST_CHECK(wallet.SelectCoinsMinConf(9990 * MIN_CHANGE / 100, 1, 1, 0,
                                               vCoins, setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 101 * MIN_CHANGE);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
 
         // test with many inputs
         for (Amount amt = Amount(1500); amt < COIN; amt = 10 * amt) {
             empty_wallet();
             // Create 676 inputs (=  (old MAX_STANDARD_TX_SIZE == 100000)  / 148
             // bytes per input)
             for (uint16_t j = 0; j < 676; j++) {
                 add_coin(wallet, amt);
             }
             BOOST_CHECK(wallet.SelectCoinsMinConf(Amount(2000), 1, 1, 0, vCoins,
                                                   setCoinsRet, nValueRet));
             if (amt - Amount(2000) < MIN_CHANGE) {
                 // needs more than one input:
                 uint16_t returnSize = std::ceil(
                     (2000.0 + MIN_CHANGE.GetSatoshis()) / amt.GetSatoshis());
                 Amount returnValue = returnSize * amt;
                 BOOST_CHECK_EQUAL(nValueRet, returnValue);
                 BOOST_CHECK_EQUAL(setCoinsRet.size(), returnSize);
             } else {
                 // one input is sufficient:
                 BOOST_CHECK_EQUAL(nValueRet, amt);
                 BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
             }
         }
 
         // test randomness
         {
             empty_wallet();
             for (int i2 = 0; i2 < 100; i2++) {
                 add_coin(wallet, COIN);
             }
 
             // picking 50 from 100 coins doesn't depend on the shuffle, but does
             // depend on randomness in the stochastic approximation code
             BOOST_CHECK(wallet.SelectCoinsMinConf(50 * COIN, 1, 6, 0, vCoins,
                                                   setCoinsRet, nValueRet));
             BOOST_CHECK(wallet.SelectCoinsMinConf(50 * COIN, 1, 6, 0, vCoins,
                                                   setCoinsRet2, nValueRet));
             BOOST_CHECK(!equal_sets(setCoinsRet, setCoinsRet2));
 
             int fails = 0;
             for (int j = 0; j < RANDOM_REPEATS; j++) {
                 // selecting 1 from 100 identical coins depends on the shuffle;
                 // this test will fail 1% of the time run the test
                 // RANDOM_REPEATS times and only complain if all of them fail
                 BOOST_CHECK(wallet.SelectCoinsMinConf(COIN, 1, 6, 0, vCoins,
                                                       setCoinsRet, nValueRet));
                 BOOST_CHECK(wallet.SelectCoinsMinConf(COIN, 1, 6, 0, vCoins,
                                                       setCoinsRet2, nValueRet));
                 if (equal_sets(setCoinsRet, setCoinsRet2)) fails++;
             }
             BOOST_CHECK_NE(fails, RANDOM_REPEATS);
 
             // add 75 cents in small change.  not enough to make 90 cents, then
             // try making 90 cents.  there are multiple competing "smallest
             // bigger" coins, one of which should be picked at random
             add_coin(wallet, 5 * CENT);
             add_coin(wallet, 10 * CENT);
             add_coin(wallet, 15 * CENT);
             add_coin(wallet, 20 * CENT);
             add_coin(wallet, 25 * CENT);
 
             fails = 0;
             for (int j = 0; j < RANDOM_REPEATS; j++) {
                 // selecting 1 from 100 identical coins depends on the shuffle;
                 // this test will fail 1% of the time run the test
                 // RANDOM_REPEATS times and only complain if all of them fail
                 BOOST_CHECK(wallet.SelectCoinsMinConf(
                     90 * CENT, 1, 6, 0, vCoins, setCoinsRet, nValueRet));
                 BOOST_CHECK(wallet.SelectCoinsMinConf(
                     90 * CENT, 1, 6, 0, vCoins, setCoinsRet2, nValueRet));
                 if (equal_sets(setCoinsRet, setCoinsRet2)) fails++;
             }
             BOOST_CHECK_NE(fails, RANDOM_REPEATS);
         }
     }
     empty_wallet();
 }
 
 BOOST_AUTO_TEST_CASE(ApproximateBestSubset) {
     CoinSet setCoinsRet;
     Amount nValueRet;
 
     const CWallet wallet(Params());
     LOCK(walletCriticalSection);
 
     empty_wallet();
 
     // Test vValue sort order
     for (int i = 0; i < 1000; i++) {
         add_coin(wallet, 1000 * COIN);
     }
     add_coin(wallet, 3 * COIN);
 
     BOOST_CHECK(wallet.SelectCoinsMinConf(1003 * COIN, 1, 6, 0, vCoins,
                                           setCoinsRet, nValueRet));
     BOOST_CHECK_EQUAL(nValueRet, 1003 * COIN);
     BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
 
     empty_wallet();
 }
 
 BOOST_FIXTURE_TEST_CASE(rescan, TestChain100Setup) {
     LOCK(cs_main);
 
     // Cap last block file size, and mine new block in a new block file.
     CBlockIndex *oldTip = chainActive.Tip();
     GetBlockFileInfo(oldTip->GetBlockPos().nFile)->nSize = MAX_BLOCKFILE_SIZE;
     CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
     CBlockIndex *newTip = chainActive.Tip();
 
     // Verify ScanForWalletTransactions picks up transactions in both the old
     // and new block files.
     {
         CWallet wallet(Params());
         LOCK(wallet.cs_wallet);
         wallet.AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
         BOOST_CHECK_EQUAL(oldTip, wallet.ScanForWalletTransactions(oldTip));
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 100 * COIN);
     }
 
     // Prune the older block file.
     PruneOneBlockFile(oldTip->GetBlockPos().nFile);
     UnlinkPrunedFiles({oldTip->GetBlockPos().nFile});
 
     // Verify ScanForWalletTransactions only picks transactions in the new block
     // file.
     {
         CWallet wallet(Params());
         LOCK(wallet.cs_wallet);
         wallet.AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
         BOOST_CHECK_EQUAL(newTip, wallet.ScanForWalletTransactions(oldTip));
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 50 * COIN);
     }
 
     // Verify importmulti RPC returns failure for a key whose creation time is
     // before the missing block, and success for a key whose creation time is
     // after.
     {
         CWallet wallet(Params());
         vpwallets.insert(vpwallets.begin(), &wallet);
         UniValue keys;
         keys.setArray();
         UniValue key;
         key.setObject();
         key.pushKV("scriptPubKey",
                    HexStr(GetScriptForRawPubKey(coinbaseKey.GetPubKey())));
         key.pushKV("timestamp", 0);
         key.pushKV("internal", UniValue(true));
         keys.push_back(key);
         key.clear();
         key.setObject();
         CKey futureKey;
         futureKey.MakeNewKey(true);
         key.pushKV("scriptPubKey",
                    HexStr(GetScriptForRawPubKey(futureKey.GetPubKey())));
         key.pushKV("timestamp", newTip->GetBlockTimeMax() + TIMESTAMP_WINDOW);
         key.pushKV("internal", UniValue(true));
         keys.push_back(key);
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(keys);
 
         UniValue response = importmulti(GetConfig(), request);
         BOOST_CHECK_EQUAL(
             response.write(),
             strprintf("[{\"success\":false,\"error\":{\"code\":-1,\"message\":"
                       "\"Failed to rescan before time %d, transactions may be "
                       "missing.\"}},{\"success\":true}]",
                       newTip->GetBlockTimeMax()));
         vpwallets.erase(vpwallets.begin());
     }
 
     // Verify ScanForWalletTransactions does not return null when the scan is
     // elided due to the nTimeFirstKey optimization.
     {
         CWallet wallet(Params());
         {
             LOCK(wallet.cs_wallet);
             wallet.UpdateTimeFirstKey(newTip->GetBlockTime() + 7200 + 1);
         }
         BOOST_CHECK_EQUAL(newTip, wallet.ScanForWalletTransactions(newTip));
     }
 }
 
 // Verify importwallet RPC starts rescan at earliest block with timestamp
 // greater or equal than key birthday. Previously there was a bug where
 // importwallet RPC would start the scan at the latest block with timestamp less
 // than or equal to key birthday.
 BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup) {
     LOCK(cs_main);
 
     // Create two blocks with same timestamp to verify that importwallet rescan
     // will pick up both blocks, not just the first.
     const int64_t BLOCK_TIME = chainActive.Tip()->GetBlockTimeMax() + 5;
     SetMockTime(BLOCK_TIME);
     coinbaseTxns.emplace_back(
         *CreateAndProcessBlock({},
                                GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
              .vtx[0]);
     coinbaseTxns.emplace_back(
         *CreateAndProcessBlock({},
                                GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
              .vtx[0]);
 
     // Set key birthday to block time increased by the timestamp window, so
     // rescan will start at the block time.
     const int64_t KEY_TIME = BLOCK_TIME + TIMESTAMP_WINDOW;
     SetMockTime(KEY_TIME);
     coinbaseTxns.emplace_back(
         *CreateAndProcessBlock({},
                                GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
              .vtx[0]);
 
     // Import key into wallet and call dumpwallet to create backup file.
     {
         CWallet wallet(Params());
         LOCK(wallet.cs_wallet);
         wallet.mapKeyMetadata[coinbaseKey.GetPubKey().GetID()].nCreateTime =
             KEY_TIME;
         wallet.AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
 
         JSONRPCRequest request;
         request.params.setArray();
-        request.params.push_back("wallet.backup");
+        request.params.push_back((pathTemp / "wallet.backup").string());
         vpwallets.insert(vpwallets.begin(), &wallet);
         ::dumpwallet(GetConfig(), request);
     }
 
     // Call importwallet RPC and verify all blocks with timestamps >= BLOCK_TIME
     // were scanned, and no prior blocks were scanned.
     {
         CWallet wallet(Params());
 
         JSONRPCRequest request;
         request.params.setArray();
-        request.params.push_back("wallet.backup");
+        request.params.push_back((pathTemp / "wallet.backup").string());
         vpwallets[0] = &wallet;
         ::importwallet(GetConfig(), request);
 
         BOOST_CHECK_EQUAL(wallet.mapWallet.size(), 3);
         BOOST_CHECK_EQUAL(coinbaseTxns.size(), 103);
         for (size_t i = 0; i < coinbaseTxns.size(); ++i) {
             bool found = wallet.GetWalletTx(coinbaseTxns[i].GetHash());
             bool expected = i >= 100;
             BOOST_CHECK_EQUAL(found, expected);
         }
     }
 
     SetMockTime(0);
     vpwallets.erase(vpwallets.begin());
 }
 
 // Check that GetImmatureCredit() returns a newly calculated value instead of
 // the cached value after a MarkDirty() call.
 //
 // This is a regression test written to verify a bugfix for the immature credit
 // function. Similar tests probably should be written for the other credit and
 // debit functions.
 BOOST_FIXTURE_TEST_CASE(coin_mark_dirty_immature_credit, TestChain100Setup) {
     CWallet wallet(Params());
     CWalletTx wtx(&wallet, MakeTransactionRef(coinbaseTxns.back()));
     LOCK2(cs_main, wallet.cs_wallet);
     wtx.hashBlock = chainActive.Tip()->GetBlockHash();
     wtx.nIndex = 0;
 
     // Call GetImmatureCredit() once before adding the key to the wallet to
     // cache the current immature credit amount, which is 0.
     BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(), Amount(0));
 
     // Invalidate the cached value, add the key, and make sure a new immature
     // credit amount is calculated.
     wtx.MarkDirty();
     wallet.AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
     BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(), 50 * COIN);
 }
 
 static int64_t AddTx(CWallet &wallet, uint32_t lockTime, int64_t mockTime,
                      int64_t blockTime) {
     CMutableTransaction tx;
     tx.nLockTime = lockTime;
     SetMockTime(mockTime);
     CBlockIndex *block = nullptr;
     if (blockTime > 0) {
         auto inserted = mapBlockIndex.emplace(GetRandHash(), new CBlockIndex);
         assert(inserted.second);
         const uint256 &hash = inserted.first->first;
         block = inserted.first->second;
         block->nTime = blockTime;
         block->phashBlock = &hash;
     }
 
     CWalletTx wtx(&wallet, MakeTransactionRef(tx));
     if (block) {
         wtx.SetMerkleBranch(block, 0);
     }
     wallet.AddToWallet(wtx);
     return wallet.mapWallet.at(wtx.GetId()).nTimeSmart;
 }
 
 // Simple test to verify assignment of CWalletTx::nSmartTime value. Could be
 // expanded to cover more corner cases of smart time logic.
 BOOST_AUTO_TEST_CASE(ComputeTimeSmart) {
     CWallet wallet(Params());
 
     // New transaction should use clock time if lower than block time.
     BOOST_CHECK_EQUAL(AddTx(wallet, 1, 100, 120), 100);
 
     // Test that updating existing transaction does not change smart time.
     BOOST_CHECK_EQUAL(AddTx(wallet, 1, 200, 220), 100);
 
     // New transaction should use clock time if there's no block time.
     BOOST_CHECK_EQUAL(AddTx(wallet, 2, 300, 0), 300);
 
     // New transaction should use block time if lower than clock time.
     BOOST_CHECK_EQUAL(AddTx(wallet, 3, 420, 400), 400);
 
     // New transaction should use latest entry time if higher than
     // min(block time, clock time).
     BOOST_CHECK_EQUAL(AddTx(wallet, 4, 500, 390), 400);
 
     // If there are future entries, new transaction should use time of the
     // newest entry that is no more than 300 seconds ahead of the clock time.
     BOOST_CHECK_EQUAL(AddTx(wallet, 5, 50, 600), 300);
 
     // Reset mock time for other tests.
     SetMockTime(0);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/test/functional/wallet-dump.py b/test/functional/wallet-dump.py
index 613bca7ae..13f2972cc 100755
--- a/test/functional/wallet-dump.py
+++ b/test/functional/wallet-dump.py
@@ -1,116 +1,120 @@
 #!/usr/bin/env python3
 # Copyright (c) 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.
 
 import os
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import assert_equal
+from test_framework.util import (assert_equal, assert_raises_rpc_error)
 
 
 def read_dump(file_name, addrs, hd_master_addr_old):
     """
     Read the given dump, count the addrs that match, count change and reserve.
     Also check that the old hd_master is inactive
     """
     with open(file_name, encoding='utf8') as inputfile:
         found_addr = 0
         found_addr_chg = 0
         found_addr_rsv = 0
         hd_master_addr_ret = None
         for line in inputfile:
             # only read non comment lines
             if line[0] != "#" and len(line) > 10:
                 # split out some data
                 key_label, comment = line.split("#")
                 # key = key_label.split(" ")[0]
                 keytype = key_label.split(" ")[2]
                 if len(comment) > 1:
                     addr_keypath = comment.split(" addr=")[1]
                     addr = addr_keypath.split(" ")[0]
                     keypath = None
                     if keytype == "inactivehdmaster=1":
                         # ensure the old master is still available
                         assert(hd_master_addr_old == addr)
                     elif keytype == "hdmaster=1":
                         # ensure we have generated a new hd master key
                         assert(hd_master_addr_old != addr)
                         hd_master_addr_ret = addr
                     else:
                         keypath = addr_keypath.rstrip().split("hdkeypath=")[1]
 
                     # count key types
                     for addrObj in addrs:
                         if addrObj['address'] == addr and addrObj['hdkeypath'] == keypath and keytype == "label=":
                             found_addr += 1
                             break
                         elif keytype == "change=1":
                             found_addr_chg += 1
                             break
                         elif keytype == "reserve=1":
                             found_addr_rsv += 1
                             break
         return found_addr, found_addr_chg, found_addr_rsv, hd_master_addr_ret
 
 
 class WalletDumpTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
         self.extra_args = [["-keypool=90"]]
 
     def setup_network(self, split=False):
         # Use 1 minute timeout because the initial getnewaddress RPC can take
         # longer than the default 30 seconds due to an expensive
         # CWallet::TopUpKeyPool call, and the encryptwallet RPC made later in
         # the test often takes even longer.
         self.add_nodes(self.num_nodes, self.extra_args, timewait=60)
         self.start_nodes()
 
     def run_test(self):
         tmpdir = self.options.tmpdir
 
         # generate 20 addresses to compare against the dump
         test_addr_count = 20
         addrs = []
         for i in range(0, test_addr_count):
             addr = self.nodes[0].getnewaddress()
             vaddr = self.nodes[0].validateaddress(
                 addr)  # required to get hd keypath
             addrs.append(vaddr)
         # Should be a no-op:
         self.nodes[0].keypoolrefill()
 
         # dump unencrypted wallet
         result = self.nodes[0].dumpwallet(
             tmpdir + "/node0/wallet.unencrypted.dump")
         assert_equal(result['filename'], os.path.abspath(
             tmpdir + "/node0/wallet.unencrypted.dump"))
 
         found_addr, found_addr_chg, found_addr_rsv, hd_master_addr_unenc = \
             read_dump(tmpdir + "/node0/wallet.unencrypted.dump", addrs, None)
         assert_equal(found_addr, test_addr_count)
         # all keys must be in the dump
         assert_equal(found_addr_chg, 50)  # 50 blocks where mined
         # 90 keys plus 100% internal keys
         assert_equal(found_addr_rsv, 90 * 2)
 
         # encrypt wallet, restart, unlock and dump
         self.nodes[0].node_encrypt_wallet('test')
         self.start_node(0)
         self.nodes[0].walletpassphrase('test', 10)
         # Should be a no-op:
         self.nodes[0].keypoolrefill()
         self.nodes[0].dumpwallet(tmpdir + "/node0/wallet.encrypted.dump")
 
         found_addr, found_addr_chg, found_addr_rsv, hd_master_addr_enc = \
             read_dump(
                 tmpdir + "/node0/wallet.encrypted.dump", addrs, hd_master_addr_unenc)
         assert_equal(found_addr, test_addr_count)
         # old reserve keys are marked as change now
         assert_equal(found_addr_chg, 90 * 2 + 50)
         assert_equal(found_addr_rsv, 90 * 2)
 
+        # Overwriting should fail
+        assert_raises_rpc_error(-8, "already exists",
+                                self.nodes[0].dumpwallet, tmpdir + "/node0/wallet.unencrypted.dump")
+
 
 if __name__ == '__main__':
     WalletDumpTest().main()