diff --git a/src/qt/test/wallettests.cpp b/src/qt/test/wallettests.cpp
index 4b03527dc..29b77f24c 100644
--- a/src/qt/test/wallettests.cpp
+++ b/src/qt/test/wallettests.cpp
@@ -1,263 +1,266 @@
 #include <qt/test/util.h>
 #include <qt/test/wallettests.h>
 
 #include <cashaddrenc.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <interfaces/chain.h>
 #include <interfaces/node.h>
 #include <key_io.h>
 #include <qt/bitcoinamountfield.h>
 #include <qt/optionsmodel.h>
 #include <qt/overviewpage.h>
 #include <qt/platformstyle.h>
 #include <qt/qvalidatedlineedit.h>
 #include <qt/receivecoinsdialog.h>
 #include <qt/receiverequestdialog.h>
 #include <qt/recentrequeststablemodel.h>
 #include <qt/sendcoinsdialog.h>
 #include <qt/sendcoinsentry.h>
 #include <qt/transactiontablemodel.h>
 #include <qt/walletmodel.h>
 #include <validation.h>
 #include <wallet/wallet.h>
 
 #include <test/util/setup_common.h>
 
 #include <QAbstractButton>
 #include <QApplication>
 #include <QDialogButtonBox>
 #include <QListView>
 #include <QPushButton>
 #include <QTextEdit>
 #include <QTimer>
 #include <QVBoxLayout>
 
 #include <memory>
 
 namespace {
 //! Press "Yes" or "Cancel" buttons in modal send confirmation dialog.
 void ConfirmSend(QString *text = nullptr, bool cancel = false) {
     QTimer::singleShot(0, Qt::PreciseTimer, [text, cancel]() {
         for (QWidget *widget : QApplication::topLevelWidgets()) {
             if (widget->inherits("SendConfirmationDialog")) {
                 SendConfirmationDialog *dialog =
                     qobject_cast<SendConfirmationDialog *>(widget);
                 if (text) {
                     *text = dialog->text();
                 }
                 QAbstractButton *button = dialog->button(
                     cancel ? QMessageBox::Cancel : QMessageBox::Yes);
                 button->setEnabled(true);
                 button->click();
             }
         }
     });
 }
 
 //! Send coins to address and return txid.
 TxId SendCoins(CWallet &wallet, SendCoinsDialog &sendCoinsDialog,
                const CTxDestination &address, Amount amount) {
     QVBoxLayout *entries = sendCoinsDialog.findChild<QVBoxLayout *>("entries");
     SendCoinsEntry *entry =
         qobject_cast<SendCoinsEntry *>(entries->itemAt(0)->widget());
     entry->findChild<QValidatedLineEdit *>("payTo")->setText(
         QString::fromStdString(EncodeCashAddr(address, Params())));
     entry->findChild<BitcoinAmountField *>("payAmount")->setValue(amount);
     TxId txid;
     boost::signals2::scoped_connection c =
         wallet.NotifyTransactionChanged.connect(
             [&txid](CWallet *, const TxId &hash, ChangeType status) {
                 if (status == CT_NEW) {
                     txid = hash;
                 }
             });
     ConfirmSend();
     bool invoked =
         QMetaObject::invokeMethod(&sendCoinsDialog, "on_sendButton_clicked");
     assert(invoked);
     return txid;
 }
 
 //! Find index of txid in transaction list.
 QModelIndex FindTx(const QAbstractItemModel &model, const uint256 &txid) {
     QString hash = QString::fromStdString(txid.ToString());
     int rows = model.rowCount({});
     for (int row = 0; row < rows; ++row) {
         QModelIndex index = model.index(row, 0, {});
         if (model.data(index, TransactionTableModel::TxHashRole) == hash) {
             return index;
         }
     }
     return {};
 }
 
 //! Simple qt wallet tests.
 //
 // Test widgets can be debugged interactively calling show() on them and
 // manually running the event loop, e.g.:
 //
 //     sendCoinsDialog.show();
 //     QEventLoop().exec();
 //
 // This also requires overriding the default minimal Qt platform:
 //
 //     src/qt/test/test_bitcoin-qt -platform xcb      # Linux
 //     src/qt/test/test_bitcoin-qt -platform windows  # Windows
 //     src/qt/test/test_bitcoin-qt -platform cocoa    # macOS
 void TestGUI(interfaces::Node &node) {
     // Set up wallet and chain with 105 blocks (5 mature blocks for spending).
     TestChain100Setup test;
     for (int i = 0; i < 5; ++i) {
         test.CreateAndProcessBlock(
             {}, GetScriptForRawPubKey(test.coinbaseKey.GetPubKey()));
     }
     node.context()->connman = std::move(test.m_node.connman);
     std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
         Params(), node.context()->chain.get(), WalletLocation(),
         WalletDatabase::CreateMock());
 
     bool firstRun;
     wallet->LoadWallet(firstRun);
     {
         auto spk_man = wallet->GetLegacyScriptPubKeyMan();
+        auto locked_chain = wallet->chain().lock();
         LOCK(wallet->cs_wallet);
         AssertLockHeld(spk_man->cs_wallet);
         wallet->SetAddressBook(
             GetDestinationForKey(test.coinbaseKey.GetPubKey(),
                                  wallet->m_default_address_type),
             "", "receive");
         spk_man->AddKeyPubKey(test.coinbaseKey, test.coinbaseKey.GetPubKey());
+        wallet->SetLastBlockProcessed(105,
+                                      ::ChainActive().Tip()->GetBlockHash());
     }
     {
         auto locked_chain = wallet->chain().lock();
         LockAssertion lock(::cs_main);
 
         WalletRescanReserver reserver(wallet.get());
         reserver.reserve();
         CWallet::ScanResult result = wallet->ScanForWalletTransactions(
             locked_chain->getBlockHash(0), BlockHash(), reserver,
             true /* fUpdate */);
         QCOMPARE(result.status, CWallet::ScanResult::SUCCESS);
         QCOMPARE(result.last_scanned_block,
                  ::ChainActive().Tip()->GetBlockHash());
         QVERIFY(result.last_failed_block.IsNull());
     }
     wallet->SetBroadcastTransactions(true);
 
     // Create widgets for sending coins and listing transactions.
     std::unique_ptr<const PlatformStyle> platformStyle(
         PlatformStyle::instantiate("other"));
     OptionsModel optionsModel(node);
     AddWallet(wallet);
     WalletModel walletModel(interfaces::MakeWallet(wallet), node,
                             platformStyle.get(), &optionsModel);
     RemoveWallet(wallet);
 
     // Send two transactions, and verify they are added to transaction list.
     SendCoinsDialog sendCoinsDialog(platformStyle.get(), &walletModel);
     TransactionTableModel *transactionTableModel =
         walletModel.getTransactionTableModel();
     QCOMPARE(transactionTableModel->rowCount({}), 105);
     TxId txid1 = SendCoins(*wallet.get(), sendCoinsDialog,
                            CTxDestination(PKHash()), 5 * COIN);
     TxId txid2 = SendCoins(*wallet.get(), sendCoinsDialog,
                            CTxDestination(PKHash()), 10 * COIN);
     QCOMPARE(transactionTableModel->rowCount({}), 107);
     QVERIFY(FindTx(*transactionTableModel, txid1).isValid());
     QVERIFY(FindTx(*transactionTableModel, txid2).isValid());
 
     // Check current balance on OverviewPage
     OverviewPage overviewPage(platformStyle.get());
     overviewPage.setWalletModel(&walletModel);
     QLabel *balanceLabel = overviewPage.findChild<QLabel *>("labelBalance");
     QString balanceText = balanceLabel->text();
     int unit = walletModel.getOptionsModel()->getDisplayUnit();
     Amount balance = walletModel.wallet().getBalance();
     QString balanceComparison = BitcoinUnits::formatWithUnit(
         unit, balance, false, BitcoinUnits::separatorAlways);
     QCOMPARE(balanceText, balanceComparison);
 
     // Check Request Payment button
     ReceiveCoinsDialog receiveCoinsDialog(platformStyle.get());
     receiveCoinsDialog.setModel(&walletModel);
     RecentRequestsTableModel *requestTableModel =
         walletModel.getRecentRequestsTableModel();
 
     // Label input
     QLineEdit *labelInput =
         receiveCoinsDialog.findChild<QLineEdit *>("reqLabel");
     labelInput->setText("TEST_LABEL_1");
 
     // Amount input
     BitcoinAmountField *amountInput =
         receiveCoinsDialog.findChild<BitcoinAmountField *>("reqAmount");
     amountInput->setValue(1 * SATOSHI);
 
     // Message input
     QLineEdit *messageInput =
         receiveCoinsDialog.findChild<QLineEdit *>("reqMessage");
     messageInput->setText("TEST_MESSAGE_1");
     int initialRowCount = requestTableModel->rowCount({});
     QPushButton *requestPaymentButton =
         receiveCoinsDialog.findChild<QPushButton *>("receiveButton");
     requestPaymentButton->click();
     for (QWidget *widget : QApplication::topLevelWidgets()) {
         if (widget->inherits("ReceiveRequestDialog")) {
             ReceiveRequestDialog *receiveRequestDialog =
                 qobject_cast<ReceiveRequestDialog *>(widget);
             QTextEdit *rlist =
                 receiveRequestDialog->QObject::findChild<QTextEdit *>("outUri");
             QString paymentText = rlist->toPlainText();
             QStringList paymentTextList = paymentText.split('\n');
             QCOMPARE(paymentTextList.at(0), QString("Payment information"));
             QVERIFY(paymentTextList.at(1).indexOf(QString("URI: bchreg:")) !=
                     -1);
             QVERIFY(paymentTextList.at(2).indexOf(QString("Address:")) != -1);
             QCOMPARE(paymentTextList.at(3),
                      QString("Amount: 0.00000001 ") +
                          QString::fromStdString(CURRENCY_UNIT));
             QCOMPARE(paymentTextList.at(4), QString("Label: TEST_LABEL_1"));
             QCOMPARE(paymentTextList.at(5), QString("Message: TEST_MESSAGE_1"));
         }
     }
 
     // Clear button
     QPushButton *clearButton =
         receiveCoinsDialog.findChild<QPushButton *>("clearButton");
     clearButton->click();
     QCOMPARE(labelInput->text(), QString(""));
     QCOMPARE(amountInput->value(), Amount::zero());
     QCOMPARE(messageInput->text(), QString(""));
 
     // Check addition to history
     int currentRowCount = requestTableModel->rowCount({});
     QCOMPARE(currentRowCount, initialRowCount + 1);
 
     // Check Remove button
     QTableView *table =
         receiveCoinsDialog.findChild<QTableView *>("recentRequestsView");
     table->selectRow(currentRowCount - 1);
     QPushButton *removeRequestButton =
         receiveCoinsDialog.findChild<QPushButton *>("removeRequestButton");
     removeRequestButton->click();
     QCOMPARE(requestTableModel->rowCount({}), currentRowCount - 1);
 }
 
 } // namespace
 
 void WalletTests::walletTests() {
 #ifdef Q_OS_MAC
     if (QApplication::platformName() == "minimal") {
         // Disable for mac on "minimal" platform to avoid crashes inside the Qt
         // framework when it tries to look up unimplemented cocoa functions,
         // and fails to handle returned nulls
         // (https://bugreports.qt.io/browse/QTBUG-49686).
         QWARN("Skipping WalletTests on mac build with 'minimal' platform set "
               "due to Qt bugs. To run AppTests, invoke with 'test_bitcoin-qt "
               "-platform cocoa' on mac, or else use a linux or windows build.");
         return;
     }
 #endif
     TestGUI(m_node);
 }
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index ea62e1609..00f1137f7 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -1,604 +1,634 @@
 // Copyright (c) 2012-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <interfaces/chain.h>
 #include <node/context.h>
 #include <policy/policy.h>
 #include <rpc/server.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/rpcdump.h>
 #include <wallet/wallet.h>
 
 #include <test/util/setup_common.h>
 #include <wallet/test/wallet_test_fixture.h>
 
 #include <boost/test/unit_test.hpp>
 
 #include <univalue.h>
 
 #include <cstdint>
 #include <memory>
 #include <vector>
 
 BOOST_FIXTURE_TEST_SUITE(wallet_tests, WalletTestingSetup)
 
 static void AddKey(CWallet &wallet, const CKey &key) {
     auto spk_man = wallet.GetLegacyScriptPubKeyMan();
     LOCK(wallet.cs_wallet);
     AssertLockHeld(spk_man->cs_wallet);
     spk_man->AddKeyPubKey(key, key.GetPubKey());
 }
 
 BOOST_FIXTURE_TEST_CASE(scan_for_wallet_transactions, TestChain100Setup) {
     // 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();
 
     NodeContext node;
     auto chain = interfaces::MakeChain(node, Params());
     auto locked_chain = chain->lock();
     LockAssertion lock(::cs_main);
 
     // Verify ScanForWalletTransactions accommodates a null start block.
     {
         CWallet wallet(Params(), chain.get(), WalletLocation(),
                        WalletDatabase::CreateDummy());
+        {
+            LOCK(wallet.cs_wallet);
+            wallet.SetLastBlockProcessed(::ChainActive().Height(),
+                                         ::ChainActive().Tip()->GetBlockHash());
+        }
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
         CWallet::ScanResult result = wallet.ScanForWalletTransactions(
             BlockHash(), BlockHash(), reserver, false /* update */);
         BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::SUCCESS);
         BOOST_CHECK(result.last_failed_block.IsNull());
         BOOST_CHECK(result.last_scanned_block.IsNull());
         BOOST_CHECK(!result.last_scanned_height);
         BOOST_CHECK_EQUAL(wallet.GetBalance().m_mine_immature, Amount::zero());
     }
 
     // Verify ScanForWalletTransactions picks up transactions in both the old
     // and new block files.
     {
         CWallet wallet(Params(), chain.get(), WalletLocation(),
                        WalletDatabase::CreateDummy());
+        {
+            LOCK(wallet.cs_wallet);
+            wallet.SetLastBlockProcessed(::ChainActive().Height(),
+                                         ::ChainActive().Tip()->GetBlockHash());
+        }
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
         CWallet::ScanResult result = wallet.ScanForWalletTransactions(
             oldTip->GetBlockHash(), BlockHash(), reserver, false /* update */);
         BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::SUCCESS);
         BOOST_CHECK(result.last_failed_block.IsNull());
         BOOST_CHECK_EQUAL(result.last_scanned_block, newTip->GetBlockHash());
         BOOST_CHECK_EQUAL(*result.last_scanned_height, newTip->nHeight);
         BOOST_CHECK_EQUAL(wallet.GetBalance().m_mine_immature, 100 * COIN);
     }
 
     // Prune the older block file.
     PruneOneBlockFile(oldTip->GetBlockPos().nFile);
     UnlinkPrunedFiles({oldTip->GetBlockPos().nFile});
 
     // Verify ScanForWalletTransactions only picks transactions in the new block
     // file.
     {
         CWallet wallet(Params(), chain.get(), WalletLocation(),
                        WalletDatabase::CreateDummy());
+        {
+            LOCK(wallet.cs_wallet);
+            wallet.SetLastBlockProcessed(::ChainActive().Height(),
+                                         ::ChainActive().Tip()->GetBlockHash());
+        }
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
         CWallet::ScanResult result = wallet.ScanForWalletTransactions(
             oldTip->GetBlockHash(), BlockHash(), reserver, false /* update */);
         BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::FAILURE);
         BOOST_CHECK_EQUAL(result.last_failed_block, oldTip->GetBlockHash());
         BOOST_CHECK_EQUAL(result.last_scanned_block, newTip->GetBlockHash());
         BOOST_CHECK_EQUAL(*result.last_scanned_height, newTip->nHeight);
         BOOST_CHECK_EQUAL(wallet.GetBalance().m_mine_immature, 50 * COIN);
     }
 
     // Prune the remaining block file.
     PruneOneBlockFile(newTip->GetBlockPos().nFile);
     UnlinkPrunedFiles({newTip->GetBlockPos().nFile});
 
     // Verify ScanForWalletTransactions scans no blocks.
     {
         CWallet wallet(Params(), chain.get(), WalletLocation(),
                        WalletDatabase::CreateDummy());
+        {
+            LOCK(wallet.cs_wallet);
+            wallet.SetLastBlockProcessed(::ChainActive().Height(),
+                                         ::ChainActive().Tip()->GetBlockHash());
+        }
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
         CWallet::ScanResult result = wallet.ScanForWalletTransactions(
             oldTip->GetBlockHash(), BlockHash(), reserver, false /* update */);
         BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::FAILURE);
         BOOST_CHECK_EQUAL(result.last_failed_block, newTip->GetBlockHash());
         BOOST_CHECK(result.last_scanned_block.IsNull());
         BOOST_CHECK(!result.last_scanned_height);
         BOOST_CHECK_EQUAL(wallet.GetBalance().m_mine_immature, Amount::zero());
     }
 }
 
 BOOST_FIXTURE_TEST_CASE(importmulti_rescan, TestChain100Setup) {
     // 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();
 
     NodeContext node;
     auto chain = interfaces::MakeChain(node, Params());
     auto locked_chain = chain->lock();
     LockAssertion lock(::cs_main);
 
     // Prune the older block file.
     PruneOneBlockFile(oldTip->GetBlockPos().nFile);
     UnlinkPrunedFiles({oldTip->GetBlockPos().nFile});
 
     // Verify importmulti RPC returns failure for a key whose creation time is
     // before the missing block, and success for a key whose creation time is
     // after.
     {
         std::shared_ptr<CWallet> wallet =
             std::make_shared<CWallet>(Params(), chain.get(), WalletLocation(),
                                       WalletDatabase::CreateDummy());
         AddWallet(wallet);
         UniValue keys;
         keys.setArray();
         UniValue key;
         key.setObject();
         key.pushKV("scriptPubKey",
                    HexStr(GetScriptForRawPubKey(coinbaseKey.GetPubKey())));
         key.pushKV("timestamp", 0);
         key.pushKV("internal", UniValue(true));
         keys.push_back(key);
         key.clear();
         key.setObject();
         CKey futureKey;
         futureKey.MakeNewKey(true);
         key.pushKV("scriptPubKey",
                    HexStr(GetScriptForRawPubKey(futureKey.GetPubKey())));
         key.pushKV("timestamp",
                    newTip->GetBlockTimeMax() + TIMESTAMP_WINDOW + 1);
         key.pushKV("internal", UniValue(true));
         keys.push_back(key);
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(keys);
 
         UniValue response = importmulti(GetConfig(), request);
         BOOST_CHECK_EQUAL(
             response.write(),
             strprintf("[{\"success\":false,\"error\":{\"code\":-1,\"message\":"
                       "\"Rescan failed for key with creation timestamp %d. "
                       "There was an error reading a block from time %d, which "
                       "is after or within %d seconds of key creation, and "
                       "could contain transactions pertaining to the key. As a "
                       "result, transactions and coins using this key may not "
                       "appear in the wallet. This error could be caused by "
                       "pruning or data corruption (see bitcoind log for "
                       "details) and could be dealt with by downloading and "
                       "rescanning the relevant blocks (see -reindex and "
                       "-rescan options).\"}},{\"success\":true}]",
                       0, oldTip->GetBlockTimeMax(), TIMESTAMP_WINDOW));
         RemoveWallet(wallet);
     }
 }
 
 // Verify importwallet RPC starts rescan at earliest block with timestamp
 // greater or equal than key birthday. Previously there was a bug where
 // importwallet RPC would start the scan at the latest block with timestamp less
 // than or equal to key birthday.
 BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup) {
     // Create two blocks with same timestamp to verify that importwallet rescan
     // will pick up both blocks, not just the first.
     const int64_t BLOCK_TIME = ::ChainActive().Tip()->GetBlockTimeMax() + 5;
     SetMockTime(BLOCK_TIME);
     m_coinbase_txns.emplace_back(
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
             .vtx[0]);
     m_coinbase_txns.emplace_back(
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
             .vtx[0]);
 
     // Set key birthday to block time increased by the timestamp window, so
     // rescan will start at the block time.
     const int64_t KEY_TIME = BLOCK_TIME + TIMESTAMP_WINDOW;
     SetMockTime(KEY_TIME);
     m_coinbase_txns.emplace_back(
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()))
             .vtx[0]);
 
     NodeContext node;
     auto chain = interfaces::MakeChain(node, Params());
     auto locked_chain = chain->lock();
     LockAssertion lock(::cs_main);
 
     std::string backup_file = (GetDataDir() / "wallet.backup").string();
 
     // Import key into wallet and call dumpwallet to create backup file.
     {
         std::shared_ptr<CWallet> wallet =
             std::make_shared<CWallet>(Params(), chain.get(), WalletLocation(),
                                       WalletDatabase::CreateDummy());
         auto spk_man = wallet->GetLegacyScriptPubKeyMan();
         LOCK(wallet->cs_wallet);
         AssertLockHeld(spk_man->cs_wallet);
         spk_man->mapKeyMetadata[coinbaseKey.GetPubKey().GetID()].nCreateTime =
             KEY_TIME;
         spk_man->AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
 
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(backup_file);
         AddWallet(wallet);
         ::dumpwallet(GetConfig(), request);
         RemoveWallet(wallet);
     }
 
     // Call importwallet RPC and verify all blocks with timestamps >= BLOCK_TIME
     // were scanned, and no prior blocks were scanned.
     {
         std::shared_ptr<CWallet> wallet =
             std::make_shared<CWallet>(Params(), chain.get(), WalletLocation(),
                                       WalletDatabase::CreateDummy());
 
         JSONRPCRequest request;
         request.params.setArray();
         request.params.push_back(backup_file);
         AddWallet(wallet);
         ::importwallet(GetConfig(), request);
         RemoveWallet(wallet);
 
         LOCK(wallet->cs_wallet);
         BOOST_CHECK_EQUAL(wallet->mapWallet.size(), 3U);
         BOOST_CHECK_EQUAL(m_coinbase_txns.size(), 103U);
         for (size_t i = 0; i < m_coinbase_txns.size(); ++i) {
             bool found = wallet->GetWalletTx(m_coinbase_txns[i]->GetId());
             bool expected = i >= 100;
             BOOST_CHECK_EQUAL(found, expected);
         }
     }
 }
 
 // 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) {
     NodeContext node;
     auto chain = interfaces::MakeChain(node, Params());
     CWallet wallet(Params(), chain.get(), WalletLocation(),
                    WalletDatabase::CreateDummy());
     auto spk_man = wallet.GetLegacyScriptPubKeyMan();
     CWalletTx wtx(&wallet, m_coinbase_txns.back());
 
     auto locked_chain = chain->lock();
     LockAssertion lock(::cs_main);
     LOCK(wallet.cs_wallet);
     AssertLockHeld(spk_man->cs_wallet);
+    wallet.SetLastBlockProcessed(::ChainActive().Height(),
+                                 ::ChainActive().Tip()->GetBlockHash());
 
     wtx.SetConf(CWalletTx::Status::CONFIRMED,
                 ::ChainActive().Tip()->GetBlockHash(), 0);
 
     // Call GetImmatureCredit() once before adding the key to the wallet to
     // cache the current immature credit amount, which is 0.
     BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(*locked_chain), Amount::zero());
 
     // Invalidate the cached value, add the key, and make sure a new immature
     // credit amount is calculated.
     wtx.MarkDirty();
     BOOST_CHECK(spk_man->AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey()));
     BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(*locked_chain), 50 * COIN);
 }
 
 static int64_t AddTx(CWallet &wallet, uint32_t lockTime, int64_t mockTime,
                      int64_t blockTime) {
     CMutableTransaction tx;
     tx.nLockTime = lockTime;
     SetMockTime(mockTime);
     CBlockIndex *block = nullptr;
     if (blockTime > 0) {
         auto locked_chain = wallet.chain().lock();
         LockAssertion lock(::cs_main);
         auto inserted =
             mapBlockIndex.emplace(BlockHash(GetRandHash()), new CBlockIndex);
         assert(inserted.second);
         const BlockHash &hash = inserted.first->first;
         block = inserted.first->second;
         block->nTime = blockTime;
         block->phashBlock = &hash;
     }
 
     CWalletTx wtx(&wallet, MakeTransactionRef(tx));
     LOCK(cs_main);
     LOCK(wallet.cs_wallet);
     // If transaction is already in map, to avoid inconsistencies,
     // unconfirmation is needed before confirm again with different block.
     std::map<TxId, CWalletTx>::iterator it = wallet.mapWallet.find(wtx.GetId());
     if (it != wallet.mapWallet.end()) {
         wtx.setUnconfirmed();
         wallet.AddToWallet(wtx);
     }
     if (block) {
         wtx.SetConf(CWalletTx::Status::CONFIRMED, block->GetBlockHash(), 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) {
     // New transaction should use clock time if lower than block time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 1, 100, 120), 100);
 
     // Test that updating existing transaction does not change smart time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 1, 200, 220), 100);
 
     // New transaction should use clock time if there's no block time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 2, 300, 0), 300);
 
     // New transaction should use block time if lower than clock time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 3, 420, 400), 400);
 
     // New transaction should use latest entry time if higher than
     // min(block time, clock time).
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 4, 500, 390), 400);
 
     // If there are future entries, new transaction should use time of the
     // newest entry that is no more than 300 seconds ahead of the clock time.
     BOOST_CHECK_EQUAL(AddTx(m_wallet, 5, 50, 600), 300);
 
     // Reset mock time for other tests.
     SetMockTime(0);
 }
 
 BOOST_AUTO_TEST_CASE(LoadReceiveRequests) {
     CTxDestination dest = PKHash();
     LOCK(m_wallet.cs_wallet);
     m_wallet.AddDestData(dest, "misc", "val_misc");
     m_wallet.AddDestData(dest, "rr0", "val_rr0");
     m_wallet.AddDestData(dest, "rr1", "val_rr1");
 
     auto values = m_wallet.GetDestValues("rr");
     BOOST_CHECK_EQUAL(values.size(), 2U);
     BOOST_CHECK_EQUAL(values[0], "val_rr0");
     BOOST_CHECK_EQUAL(values[1], "val_rr1");
 }
 
 // Test some watch-only LegacyScriptPubKeyMan methods by the procedure of
 // loading (LoadWatchOnly), checking (HaveWatchOnly), getting (GetWatchPubKey)
 // and removing (RemoveWatchOnly) a given PubKey, resp. its corresponding P2PK
 // Script. Results of the the impact on the address -> PubKey map is dependent
 // on whether the PubKey is a point on the curve
 static void TestWatchOnlyPubKey(LegacyScriptPubKeyMan *spk_man,
                                 const CPubKey &add_pubkey) {
     CScript p2pk = GetScriptForRawPubKey(add_pubkey);
     CKeyID add_address = add_pubkey.GetID();
     CPubKey found_pubkey;
     LOCK(spk_man->cs_wallet);
 
     // all Scripts (i.e. also all PubKeys) are added to the general watch-only
     // set
     BOOST_CHECK(!spk_man->HaveWatchOnly(p2pk));
     spk_man->LoadWatchOnly(p2pk);
     BOOST_CHECK(spk_man->HaveWatchOnly(p2pk));
 
     // only PubKeys on the curve shall be added to the watch-only address ->
     // PubKey map
     bool is_pubkey_fully_valid = add_pubkey.IsFullyValid();
     if (is_pubkey_fully_valid) {
         BOOST_CHECK(spk_man->GetWatchPubKey(add_address, found_pubkey));
         BOOST_CHECK(found_pubkey == add_pubkey);
     } else {
         BOOST_CHECK(!spk_man->GetWatchPubKey(add_address, found_pubkey));
         // passed key is unchanged
         BOOST_CHECK(found_pubkey == CPubKey());
     }
 
     AssertLockHeld(spk_man->cs_wallet);
     spk_man->RemoveWatchOnly(p2pk);
     BOOST_CHECK(!spk_man->HaveWatchOnly(p2pk));
 
     if (is_pubkey_fully_valid) {
         BOOST_CHECK(!spk_man->GetWatchPubKey(add_address, found_pubkey));
         // passed key is unchanged
         BOOST_CHECK(found_pubkey == add_pubkey);
     }
 }
 
 // Cryptographically invalidate a PubKey whilst keeping length and first byte
 static void PollutePubKey(CPubKey &pubkey) {
     std::vector<uint8_t> pubkey_raw(pubkey.begin(), pubkey.end());
     std::fill(pubkey_raw.begin() + 1, pubkey_raw.end(), 0);
     pubkey = CPubKey(pubkey_raw);
     assert(!pubkey.IsFullyValid());
     assert(pubkey.IsValid());
 }
 
 // Test watch-only logic for PubKeys
 BOOST_AUTO_TEST_CASE(WatchOnlyPubKeys) {
     CKey key;
     CPubKey pubkey;
     LegacyScriptPubKeyMan *spk_man = m_wallet.GetLegacyScriptPubKeyMan();
 
     BOOST_CHECK(!spk_man->HaveWatchOnly());
 
     // uncompressed valid PubKey
     key.MakeNewKey(false);
     pubkey = key.GetPubKey();
     assert(!pubkey.IsCompressed());
     TestWatchOnlyPubKey(spk_man, pubkey);
 
     // uncompressed cryptographically invalid PubKey
     PollutePubKey(pubkey);
     TestWatchOnlyPubKey(spk_man, pubkey);
 
     // compressed valid PubKey
     key.MakeNewKey(true);
     pubkey = key.GetPubKey();
     assert(pubkey.IsCompressed());
     TestWatchOnlyPubKey(spk_man, pubkey);
 
     // compressed cryptographically invalid PubKey
     PollutePubKey(pubkey);
     TestWatchOnlyPubKey(spk_man, pubkey);
 
     // invalid empty PubKey
     pubkey = CPubKey();
     TestWatchOnlyPubKey(spk_man, pubkey);
 }
 
 class ListCoinsTestingSetup : public TestChain100Setup {
 public:
     ListCoinsTestingSetup() {
         CreateAndProcessBlock({},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
         wallet =
             std::make_unique<CWallet>(Params(), m_chain.get(), WalletLocation(),
                                       WalletDatabase::CreateMock());
+        {
+            LOCK(wallet->cs_wallet);
+            wallet->SetLastBlockProcessed(
+                ::ChainActive().Height(),
+                ::ChainActive().Tip()->GetBlockHash());
+        }
         bool firstRun;
         wallet->LoadWallet(firstRun);
         AddKey(*wallet, coinbaseKey);
         WalletRescanReserver reserver(wallet.get());
         reserver.reserve();
         CWallet::ScanResult result = wallet->ScanForWalletTransactions(
             ::ChainActive().Genesis()->GetBlockHash(), BlockHash(), reserver,
             false /* update */);
         BOOST_CHECK_EQUAL(result.status, CWallet::ScanResult::SUCCESS);
         BOOST_CHECK_EQUAL(result.last_scanned_block,
                           ::ChainActive().Tip()->GetBlockHash());
         BOOST_CHECK_EQUAL(*result.last_scanned_height,
                           ::ChainActive().Height());
         BOOST_CHECK(result.last_failed_block.IsNull());
     }
 
     ~ListCoinsTestingSetup() { wallet.reset(); }
 
     CWalletTx &AddTx(CRecipient recipient) {
         CTransactionRef tx;
         Amount fee;
         int changePos = -1;
         std::string error;
         CCoinControl dummy;
         {
             auto locked_chain = m_chain->lock();
             BOOST_CHECK(wallet->CreateTransaction(
                 *locked_chain, {recipient}, tx, fee, changePos, error, dummy));
         }
         wallet->CommitTransaction(tx, {}, {});
         CMutableTransaction blocktx;
         {
             LOCK(wallet->cs_wallet);
             blocktx =
                 CMutableTransaction(*wallet->mapWallet.at(tx->GetId()).tx);
         }
         CreateAndProcessBlock({CMutableTransaction(blocktx)},
                               GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
 
         LOCK(cs_main);
         LOCK(wallet->cs_wallet);
+        wallet->SetLastBlockProcessed(wallet->GetLastBlockHeight() + 1,
+                                      ::ChainActive().Tip()->GetBlockHash());
         auto it = wallet->mapWallet.find(tx->GetId());
         BOOST_CHECK(it != wallet->mapWallet.end());
         it->second.SetConf(CWalletTx::Status::CONFIRMED,
                            ::ChainActive().Tip()->GetBlockHash(), 1);
         return it->second;
     }
 
     std::unique_ptr<interfaces::Chain> m_chain =
         interfaces::MakeChain(m_node, Params());
     std::unique_ptr<CWallet> wallet;
 };
 
 BOOST_FIXTURE_TEST_CASE(ListCoins, ListCoinsTestingSetup) {
     std::string coinbaseAddress = coinbaseKey.GetPubKey().GetID().ToString();
 
     // Confirm ListCoins initially returns 1 coin grouped under coinbaseKey
     // address.
     std::map<CTxDestination, std::vector<COutput>> list;
     {
         auto locked_chain = m_chain->lock();
         LOCK(wallet->cs_wallet);
         list = wallet->ListCoins(*locked_chain);
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
     BOOST_CHECK_EQUAL(boost::get<PKHash>(list.begin()->first).ToString(),
                       coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 1U);
 
     // Check initial balance from one mature coinbase transaction.
     BOOST_CHECK_EQUAL(50 * COIN, wallet->GetAvailableBalance());
 
     // Add a transaction creating a change address, and confirm ListCoins still
     // returns the coin associated with the change address underneath the
     // coinbaseKey pubkey, even though the change address has a different
     // pubkey.
     AddTx(CRecipient{GetScriptForRawPubKey({}), 1 * COIN,
                      false /* subtract fee */});
     {
         auto locked_chain = m_chain->lock();
         LOCK(wallet->cs_wallet);
         list = wallet->ListCoins(*locked_chain);
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
     BOOST_CHECK_EQUAL(boost::get<PKHash>(list.begin()->first).ToString(),
                       coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 2U);
 
     // Lock both coins. Confirm number of available coins drops to 0.
     {
         auto locked_chain = m_chain->lock();
         LOCK(wallet->cs_wallet);
         std::vector<COutput> available;
         wallet->AvailableCoins(*locked_chain, available);
         BOOST_CHECK_EQUAL(available.size(), 2U);
     }
     for (const auto &group : list) {
         for (const auto &coin : group.second) {
             LOCK(wallet->cs_wallet);
             wallet->LockCoin(COutPoint(coin.tx->GetId(), coin.i));
         }
     }
     {
         auto locked_chain = m_chain->lock();
         LOCK(wallet->cs_wallet);
         std::vector<COutput> available;
         wallet->AvailableCoins(*locked_chain, available);
         BOOST_CHECK_EQUAL(available.size(), 0U);
     }
     // Confirm ListCoins still returns same result as before, despite coins
     // being locked.
     {
         auto locked_chain = m_chain->lock();
         LOCK(wallet->cs_wallet);
         list = wallet->ListCoins(*locked_chain);
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
     BOOST_CHECK_EQUAL(boost::get<PKHash>(list.begin()->first).ToString(),
                       coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 2U);
 }
 
 BOOST_FIXTURE_TEST_CASE(wallet_disableprivkeys, TestChain100Setup) {
     NodeContext node;
     auto chain = interfaces::MakeChain(node, Params());
     std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(
         Params(), chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
     wallet->SetMinVersion(FEATURE_LATEST);
     wallet->SetWalletFlag(WALLET_FLAG_DISABLE_PRIVATE_KEYS);
     BOOST_CHECK(!wallet->TopUpKeyPool(1000));
     CTxDestination dest;
     std::string error;
     BOOST_CHECK(
         !wallet->GetNewDestination(OutputType::LEGACY, "", dest, error));
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 0b61b9dfc..aa9bb62b1 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1,4492 +1,4496 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <wallet/wallet.h>
 
 #include <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/consensus.h>
 #include <consensus/validation.h>
 #include <fs.h>
 #include <interfaces/wallet.h>
 #include <key.h>
 #include <key_io.h>
 #include <policy/mempool.h>
 #include <policy/policy.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <random.h>
 #include <script/descriptor.h>
 #include <script/script.h>
 #include <script/sighashtype.h>
 #include <script/sign.h>
 #include <script/signingprovider.h>
 #include <util/bip32.h>
 #include <util/error.h>
 #include <util/moneystr.h>
 #include <util/translation.h>
 #include <util/validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/fees.h>
 
 #include <boost/algorithm/string/replace.hpp>
 
 #include <cassert>
 
 const std::map<uint64_t, std::string> WALLET_FLAG_CAVEATS{
     {WALLET_FLAG_AVOID_REUSE,
      "You need to rescan the blockchain in order to correctly mark used "
      "destinations in the past. Until this is done, some destinations may "
      "be considered unused, even if the opposite is the case."},
 };
 
 static RecursiveMutex cs_wallets;
 static std::vector<std::shared_ptr<CWallet>> vpwallets GUARDED_BY(cs_wallets);
 
 bool AddWallet(const std::shared_ptr<CWallet> &wallet) {
     LOCK(cs_wallets);
     assert(wallet);
     std::vector<std::shared_ptr<CWallet>>::const_iterator i =
         std::find(vpwallets.begin(), vpwallets.end(), wallet);
     if (i != vpwallets.end()) {
         return false;
     }
     vpwallets.push_back(wallet);
     return true;
 }
 
 bool RemoveWallet(const std::shared_ptr<CWallet> &wallet) {
     assert(wallet);
     // Unregister with the validation interface which also drops shared ponters.
     wallet->m_chain_notifications_handler.reset();
     LOCK(cs_wallets);
     std::vector<std::shared_ptr<CWallet>>::iterator i =
         std::find(vpwallets.begin(), vpwallets.end(), wallet);
     if (i == vpwallets.end()) {
         return false;
     }
     vpwallets.erase(i);
     return true;
 }
 
 bool HasWallets() {
     LOCK(cs_wallets);
     return !vpwallets.empty();
 }
 
 std::vector<std::shared_ptr<CWallet>> GetWallets() {
     LOCK(cs_wallets);
     return vpwallets;
 }
 
 std::shared_ptr<CWallet> GetWallet(const std::string &name) {
     LOCK(cs_wallets);
     for (const std::shared_ptr<CWallet> &wallet : vpwallets) {
         if (wallet->GetName() == name) {
             return wallet;
         }
     }
     return nullptr;
 }
 
 static Mutex g_wallet_release_mutex;
 static std::condition_variable g_wallet_release_cv;
 static std::set<std::string> g_unloading_wallet_set;
 
 // Custom deleter for shared_ptr<CWallet>.
 static void ReleaseWallet(CWallet *wallet) {
     const std::string name = wallet->GetName();
     wallet->WalletLogPrintf("Releasing wallet\n");
     wallet->Flush();
     delete wallet;
     // Wallet is now released, notify UnloadWallet, if any.
     {
         LOCK(g_wallet_release_mutex);
         if (g_unloading_wallet_set.erase(name) == 0) {
             // UnloadWallet was not called for this wallet, all done.
             return;
         }
     }
     g_wallet_release_cv.notify_all();
 }
 
 void UnloadWallet(std::shared_ptr<CWallet> &&wallet) {
     // Mark wallet for unloading.
     const std::string name = wallet->GetName();
     {
         LOCK(g_wallet_release_mutex);
         auto it = g_unloading_wallet_set.insert(name);
         assert(it.second);
     }
     // The wallet can be in use so it's not possible to explicitly unload here.
     // Notify the unload intent so that all remaining shared pointers are
     // released.
     wallet->NotifyUnload();
 
     // Time to ditch our shared_ptr and wait for ReleaseWallet call.
     wallet.reset();
     {
         WAIT_LOCK(g_wallet_release_mutex, lock);
         while (g_unloading_wallet_set.count(name) == 1) {
             g_wallet_release_cv.wait(lock);
         }
     }
 }
 
 static const size_t OUTPUT_GROUP_MAX_ENTRIES = 10;
 
 std::shared_ptr<CWallet> LoadWallet(const CChainParams &chainParams,
                                     interfaces::Chain &chain,
                                     const WalletLocation &location,
                                     std::string &error,
                                     std::vector<std::string> &warnings) {
     if (!CWallet::Verify(chainParams, chain, location, false, error,
                          warnings)) {
         error = "Wallet file verification failed: " + error;
         return nullptr;
     }
 
     std::shared_ptr<CWallet> wallet = CWallet::CreateWalletFromFile(
         chainParams, chain, location, error, warnings);
     if (!wallet) {
         error = "Wallet loading failed: " + error;
         return nullptr;
     }
     AddWallet(wallet);
     wallet->postInitProcess();
     return wallet;
 }
 
 std::shared_ptr<CWallet> LoadWallet(const CChainParams &chainParams,
                                     interfaces::Chain &chain,
                                     const std::string &name, std::string &error,
                                     std::vector<std::string> &warnings) {
     return LoadWallet(chainParams, chain, WalletLocation(name), error,
                       warnings);
 }
 
 WalletCreationStatus CreateWallet(const CChainParams &params,
                                   interfaces::Chain &chain,
                                   const SecureString &passphrase,
                                   uint64_t wallet_creation_flags,
                                   const std::string &name, std::string &error,
                                   std::vector<std::string> &warnings,
                                   std::shared_ptr<CWallet> &result) {
     // Indicate that the wallet is actually supposed to be blank and not just
     // blank to make it encrypted
     bool create_blank = (wallet_creation_flags & WALLET_FLAG_BLANK_WALLET);
 
     // Born encrypted wallets need to be created blank first.
     if (!passphrase.empty()) {
         wallet_creation_flags |= WALLET_FLAG_BLANK_WALLET;
     }
 
     // Check the wallet file location
     WalletLocation location(name);
     if (location.Exists()) {
         error = "Wallet " + location.GetName() + " already exists.";
         return WalletCreationStatus::CREATION_FAILED;
     }
 
     // Wallet::Verify will check if we're trying to create a wallet with a
     // duplicate name.
     if (!CWallet::Verify(params, chain, location, false, error, warnings)) {
         error = "Wallet file verification failed: " + error;
         return WalletCreationStatus::CREATION_FAILED;
     }
 
     // Do not allow a passphrase when private keys are disabled
     if (!passphrase.empty() &&
         (wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         error = "Passphrase provided but private keys are disabled. A "
                 "passphrase is only used to encrypt private keys, so cannot be "
                 "used for wallets with private keys disabled.";
         return WalletCreationStatus::CREATION_FAILED;
     }
 
     // Make the wallet
     std::shared_ptr<CWallet> wallet = CWallet::CreateWalletFromFile(
         params, chain, location, error, warnings, wallet_creation_flags);
     if (!wallet) {
         error = "Wallet creation failed: " + error;
         return WalletCreationStatus::CREATION_FAILED;
     }
 
     // Encrypt the wallet
     if (!passphrase.empty() &&
         !(wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         if (!wallet->EncryptWallet(passphrase)) {
             error = "Error: Wallet created but failed to encrypt.";
             return WalletCreationStatus::ENCRYPTION_FAILED;
         }
         if (!create_blank) {
             // Unlock the wallet
             if (!wallet->Unlock(passphrase)) {
                 error = "Error: Wallet was encrypted but could not be unlocked";
                 return WalletCreationStatus::ENCRYPTION_FAILED;
             }
 
             // Set a seed for the wallet
             {
                 if (auto spk_man = wallet->m_spk_man.get()) {
                     if (!spk_man->SetupGeneration()) {
                         error = "Unable to generate initial keys";
                         return WalletCreationStatus::CREATION_FAILED;
                     }
                 }
             }
 
             // Relock the wallet
             wallet->Lock();
         }
     }
     AddWallet(wallet);
     wallet->postInitProcess();
     result = wallet;
     return WalletCreationStatus::SUCCESS;
 }
 
 const BlockHash CWalletTx::ABANDON_HASH(uint256S(
     "0000000000000000000000000000000000000000000000000000000000000001"));
 
 /** @defgroup mapWallet
  *
  * @{
  */
 
 std::string COutput::ToString() const {
     return strprintf("COutput(%s, %d, %d) [%s]", tx->GetId().ToString(), i,
                      nDepth, FormatMoney(tx->tx->vout[i].nValue));
 }
 
 const CWalletTx *CWallet::GetWalletTx(const TxId &txid) const {
     LOCK(cs_wallet);
     std::map<TxId, CWalletTx>::const_iterator it = mapWallet.find(txid);
     if (it == mapWallet.end()) {
         return nullptr;
     }
 
     return &(it->second);
 }
 
 void CWallet::UpgradeKeyMetadata() {
     if (IsLocked() || IsWalletFlagSet(WALLET_FLAG_KEY_ORIGIN_METADATA)) {
         return;
     }
 
     if (m_spk_man) {
         AssertLockHeld(m_spk_man->cs_wallet);
         m_spk_man->UpgradeKeyMetadata();
     }
     SetWalletFlag(WALLET_FLAG_KEY_ORIGIN_METADATA);
 }
 
 bool CWallet::Unlock(const SecureString &strWalletPassphrase,
                      bool accept_no_keys) {
     CCrypter crypter;
     CKeyingMaterial _vMasterKey;
 
     {
         LOCK(cs_wallet);
         for (const MasterKeyMap::value_type &pMasterKey : mapMasterKeys) {
             if (!crypter.SetKeyFromPassphrase(
                     strWalletPassphrase, pMasterKey.second.vchSalt,
                     pMasterKey.second.nDeriveIterations,
                     pMasterKey.second.nDerivationMethod)) {
                 return false;
             }
             if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey,
                                  _vMasterKey)) {
                 // try another master key
                 continue;
             }
             if (Unlock(_vMasterKey, accept_no_keys)) {
                 // Now that we've unlocked, upgrade the key metadata
                 UpgradeKeyMetadata();
                 return true;
             }
         }
     }
 
     return false;
 }
 
 bool CWallet::ChangeWalletPassphrase(
     const SecureString &strOldWalletPassphrase,
     const SecureString &strNewWalletPassphrase) {
     bool fWasLocked = IsLocked();
 
     LOCK(cs_wallet);
     Lock();
 
     CCrypter crypter;
     CKeyingMaterial _vMasterKey;
     for (MasterKeyMap::value_type &pMasterKey : mapMasterKeys) {
         if (!crypter.SetKeyFromPassphrase(
                 strOldWalletPassphrase, pMasterKey.second.vchSalt,
                 pMasterKey.second.nDeriveIterations,
                 pMasterKey.second.nDerivationMethod)) {
             return false;
         }
 
         if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey, _vMasterKey)) {
             return false;
         }
 
         if (Unlock(_vMasterKey)) {
             int64_t nStartTime = GetTimeMillis();
             crypter.SetKeyFromPassphrase(strNewWalletPassphrase,
                                          pMasterKey.second.vchSalt,
                                          pMasterKey.second.nDeriveIterations,
                                          pMasterKey.second.nDerivationMethod);
             pMasterKey.second.nDeriveIterations = static_cast<unsigned int>(
                 pMasterKey.second.nDeriveIterations *
                 (100 / ((double)(GetTimeMillis() - nStartTime))));
 
             nStartTime = GetTimeMillis();
             crypter.SetKeyFromPassphrase(strNewWalletPassphrase,
                                          pMasterKey.second.vchSalt,
                                          pMasterKey.second.nDeriveIterations,
                                          pMasterKey.second.nDerivationMethod);
             pMasterKey.second.nDeriveIterations =
                 (pMasterKey.second.nDeriveIterations +
                  static_cast<unsigned int>(
                      pMasterKey.second.nDeriveIterations * 100 /
                      double(GetTimeMillis() - nStartTime))) /
                 2;
 
             if (pMasterKey.second.nDeriveIterations < 25000) {
                 pMasterKey.second.nDeriveIterations = 25000;
             }
 
             WalletLogPrintf(
                 "Wallet passphrase changed to an nDeriveIterations of %i\n",
                 pMasterKey.second.nDeriveIterations);
 
             if (!crypter.SetKeyFromPassphrase(
                     strNewWalletPassphrase, pMasterKey.second.vchSalt,
                     pMasterKey.second.nDeriveIterations,
                     pMasterKey.second.nDerivationMethod)) {
                 return false;
             }
 
             if (!crypter.Encrypt(_vMasterKey,
                                  pMasterKey.second.vchCryptedKey)) {
                 return false;
             }
 
             WalletBatch(*database).WriteMasterKey(pMasterKey.first,
                                                   pMasterKey.second);
             if (fWasLocked) {
                 Lock();
             }
 
             return true;
         }
     }
 
     return false;
 }
 
 void CWallet::ChainStateFlushed(const CBlockLocator &loc) {
     WalletBatch batch(*database);
     batch.WriteBestBlock(loc);
 }
 
 void CWallet::SetMinVersion(enum WalletFeature nVersion, WalletBatch *batch_in,
                             bool fExplicit) {
     LOCK(cs_wallet);
     if (nWalletVersion >= nVersion) {
         return;
     }
 
     // When doing an explicit upgrade, if we pass the max version permitted,
     // upgrade all the way.
     if (fExplicit && nVersion > nWalletMaxVersion) {
         nVersion = FEATURE_LATEST;
     }
 
     nWalletVersion = nVersion;
 
     if (nVersion > nWalletMaxVersion) {
         nWalletMaxVersion = nVersion;
     }
 
     WalletBatch *batch = batch_in ? batch_in : new WalletBatch(*database);
     if (nWalletVersion > 40000) {
         batch->WriteMinVersion(nWalletVersion);
     }
     if (!batch_in) {
         delete batch;
     }
 }
 
 bool CWallet::SetMaxVersion(int nVersion) {
     LOCK(cs_wallet);
 
     // Cannot downgrade below current version
     if (nWalletVersion > nVersion) {
         return false;
     }
 
     nWalletMaxVersion = nVersion;
 
     return true;
 }
 
 std::set<TxId> CWallet::GetConflicts(const TxId &txid) const {
     std::set<TxId> result;
     AssertLockHeld(cs_wallet);
 
     std::map<TxId, CWalletTx>::const_iterator it = mapWallet.find(txid);
     if (it == mapWallet.end()) {
         return result;
     }
 
     const CWalletTx &wtx = it->second;
 
     std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range;
 
     for (const CTxIn &txin : wtx.tx->vin) {
         if (mapTxSpends.count(txin.prevout) <= 1) {
             // No conflict if zero or one spends.
             continue;
         }
 
         range = mapTxSpends.equal_range(txin.prevout);
         for (TxSpends::const_iterator _it = range.first; _it != range.second;
              ++_it) {
             result.insert(_it->second);
         }
     }
 
     return result;
 }
 
 bool CWallet::HasWalletSpend(const TxId &txid) const {
     AssertLockHeld(cs_wallet);
     auto iter = mapTxSpends.lower_bound(COutPoint(txid, 0));
     return (iter != mapTxSpends.end() && iter->first.GetTxId() == txid);
 }
 
 void CWallet::Flush(bool shutdown) {
     database->Flush(shutdown);
 }
 
 void CWallet::SyncMetaData(
     std::pair<TxSpends::iterator, TxSpends::iterator> range) {
     // We want all the wallet transactions in range to have the same metadata as
     // the oldest (smallest nOrderPos).
     // So: find smallest nOrderPos:
 
     int nMinOrderPos = std::numeric_limits<int>::max();
     const CWalletTx *copyFrom = nullptr;
     for (TxSpends::iterator it = range.first; it != range.second; ++it) {
         const CWalletTx *wtx = &mapWallet.at(it->second);
         if (wtx->nOrderPos < nMinOrderPos) {
             nMinOrderPos = wtx->nOrderPos;
             copyFrom = wtx;
         }
     }
 
     if (!copyFrom) {
         return;
     }
 
     // Now copy data from copyFrom to rest:
     for (TxSpends::iterator it = range.first; it != range.second; ++it) {
         const TxId &txid = it->second;
         CWalletTx *copyTo = &mapWallet.at(txid);
         if (copyFrom == copyTo) {
             continue;
         }
 
         assert(
             copyFrom &&
             "Oldest wallet transaction in range assumed to have been found.");
 
         if (!copyFrom->IsEquivalentTo(*copyTo)) {
             continue;
         }
 
         copyTo->mapValue = copyFrom->mapValue;
         copyTo->vOrderForm = copyFrom->vOrderForm;
         // fTimeReceivedIsTxTime not copied on purpose nTimeReceived not copied
         // on purpose.
         copyTo->nTimeSmart = copyFrom->nTimeSmart;
         copyTo->fFromMe = copyFrom->fFromMe;
         // nOrderPos not copied on purpose cached members not copied on purpose.
     }
 }
 
 /**
  * Outpoint is spent if any non-conflicted transaction, spends it:
  */
 bool CWallet::IsSpent(interfaces::Chain::Lock &locked_chain,
                       const COutPoint &outpoint) const {
     std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range =
         mapTxSpends.equal_range(outpoint);
 
     for (TxSpends::const_iterator it = range.first; it != range.second; ++it) {
         const TxId &wtxid = it->second;
         std::map<TxId, CWalletTx>::const_iterator mit = mapWallet.find(wtxid);
         if (mit != mapWallet.end()) {
             int depth = mit->second.GetDepthInMainChain(locked_chain);
             if (depth > 0 || (depth == 0 && !mit->second.isAbandoned())) {
                 // Spent
                 return true;
             }
         }
     }
 
     return false;
 }
 
 void CWallet::AddToSpends(const COutPoint &outpoint, const TxId &wtxid) {
     mapTxSpends.insert(std::make_pair(outpoint, wtxid));
 
     setLockedCoins.erase(outpoint);
 
     std::pair<TxSpends::iterator, TxSpends::iterator> range;
     range = mapTxSpends.equal_range(outpoint);
     SyncMetaData(range);
 }
 
 void CWallet::AddToSpends(const TxId &wtxid) {
     auto it = mapWallet.find(wtxid);
     assert(it != mapWallet.end());
     CWalletTx &thisTx = it->second;
     // Coinbases don't spend anything!
     if (thisTx.IsCoinBase()) {
         return;
     }
 
     for (const CTxIn &txin : thisTx.tx->vin) {
         AddToSpends(txin.prevout, wtxid);
     }
 }
 
 bool CWallet::EncryptWallet(const SecureString &strWalletPassphrase) {
     if (IsCrypted()) {
         return false;
     }
 
     CKeyingMaterial _vMasterKey;
 
     _vMasterKey.resize(WALLET_CRYPTO_KEY_SIZE);
     GetStrongRandBytes(&_vMasterKey[0], WALLET_CRYPTO_KEY_SIZE);
 
     CMasterKey kMasterKey;
 
     kMasterKey.vchSalt.resize(WALLET_CRYPTO_SALT_SIZE);
     GetStrongRandBytes(&kMasterKey.vchSalt[0], WALLET_CRYPTO_SALT_SIZE);
 
     CCrypter crypter;
     int64_t nStartTime = GetTimeMillis();
     crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt, 25000,
                                  kMasterKey.nDerivationMethod);
     kMasterKey.nDeriveIterations = static_cast<unsigned int>(
         2500000 / double(GetTimeMillis() - nStartTime));
 
     nStartTime = GetTimeMillis();
     crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt,
                                  kMasterKey.nDeriveIterations,
                                  kMasterKey.nDerivationMethod);
     kMasterKey.nDeriveIterations =
         (kMasterKey.nDeriveIterations +
          static_cast<unsigned int>(kMasterKey.nDeriveIterations * 100 /
                                    double(GetTimeMillis() - nStartTime))) /
         2;
 
     if (kMasterKey.nDeriveIterations < 25000) {
         kMasterKey.nDeriveIterations = 25000;
     }
 
     WalletLogPrintf("Encrypting Wallet with an nDeriveIterations of %i\n",
                     kMasterKey.nDeriveIterations);
 
     if (!crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt,
                                       kMasterKey.nDeriveIterations,
                                       kMasterKey.nDerivationMethod)) {
         return false;
     }
 
     if (!crypter.Encrypt(_vMasterKey, kMasterKey.vchCryptedKey)) {
         return false;
     }
 
     {
         LOCK(cs_wallet);
         mapMasterKeys[++nMasterKeyMaxID] = kMasterKey;
         assert(!encrypted_batch);
         encrypted_batch = new WalletBatch(*database);
         if (!encrypted_batch->TxnBegin()) {
             delete encrypted_batch;
             encrypted_batch = nullptr;
             return false;
         }
         encrypted_batch->WriteMasterKey(nMasterKeyMaxID, kMasterKey);
 
         if (auto spk_man = m_spk_man.get()) {
             if (!spk_man->EncryptKeys(_vMasterKey)) {
                 encrypted_batch->TxnAbort();
                 delete encrypted_batch;
                 encrypted_batch = nullptr;
                 // We now probably have half of our keys encrypted in memory,
                 // and half not... die and let the user reload the unencrypted
                 // wallet.
                 assert(false);
             }
         }
 
         // Encryption was introduced in version 0.4.0
         SetMinVersion(FEATURE_WALLETCRYPT, encrypted_batch, true);
 
         if (!encrypted_batch->TxnCommit()) {
             delete encrypted_batch;
             encrypted_batch = nullptr;
             // We now have keys encrypted in memory, but not on disk...
             // die to avoid confusion and let the user reload the unencrypted
             // wallet.
             assert(false);
         }
 
         delete encrypted_batch;
         encrypted_batch = nullptr;
 
         Lock();
         Unlock(strWalletPassphrase);
 
         // if we are using HD, replace the HD seed with a new one
         if (auto spk_man = m_spk_man.get()) {
             if (spk_man->IsHDEnabled()) {
                 if (!spk_man->SetupGeneration(true)) {
                     return false;
                 }
             }
         }
         Lock();
 
         // Need to completely rewrite the wallet file; if we don't, bdb might
         // keep bits of the unencrypted private key in slack space in the
         // database file.
         database->Rewrite();
 
         // BDB seems to have a bad habit of writing old data into
         // slack space in .dat files; that is bad if the old data is
         // unencrypted private keys. So:
         database->ReloadDbEnv();
     }
 
     NotifyStatusChanged(this);
     return true;
 }
 
 DBErrors CWallet::ReorderTransactions() {
     LOCK(cs_wallet);
     WalletBatch batch(*database);
 
     // Old wallets didn't have any defined order for transactions. Probably a
     // bad idea to change the output of this.
 
     // First: get all CWalletTx into a sorted-by-time
     // multimap.
     TxItems txByTime;
 
     for (auto &entry : mapWallet) {
         CWalletTx *wtx = &entry.second;
         txByTime.insert(std::make_pair(wtx->nTimeReceived, wtx));
     }
 
     nOrderPosNext = 0;
     std::vector<int64_t> nOrderPosOffsets;
     for (TxItems::iterator it = txByTime.begin(); it != txByTime.end(); ++it) {
         CWalletTx *const pwtx = (*it).second;
         int64_t &nOrderPos = pwtx->nOrderPos;
 
         if (nOrderPos == -1) {
             nOrderPos = nOrderPosNext++;
             nOrderPosOffsets.push_back(nOrderPos);
 
             if (!batch.WriteTx(*pwtx)) {
                 return DBErrors::LOAD_FAIL;
             }
         } else {
             int64_t nOrderPosOff = 0;
             for (const int64_t &nOffsetStart : nOrderPosOffsets) {
                 if (nOrderPos >= nOffsetStart) {
                     ++nOrderPosOff;
                 }
             }
 
             nOrderPos += nOrderPosOff;
             nOrderPosNext = std::max(nOrderPosNext, nOrderPos + 1);
 
             if (!nOrderPosOff) {
                 continue;
             }
 
             // Since we're changing the order, write it back.
             if (!batch.WriteTx(*pwtx)) {
                 return DBErrors::LOAD_FAIL;
             }
         }
     }
 
     batch.WriteOrderPosNext(nOrderPosNext);
 
     return DBErrors::LOAD_OK;
 }
 
 int64_t CWallet::IncOrderPosNext(WalletBatch *batch) {
     AssertLockHeld(cs_wallet);
     int64_t nRet = nOrderPosNext++;
     if (batch) {
         batch->WriteOrderPosNext(nOrderPosNext);
     } else {
         WalletBatch(*database).WriteOrderPosNext(nOrderPosNext);
     }
 
     return nRet;
 }
 
 void CWallet::MarkDirty() {
     LOCK(cs_wallet);
     for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
         item.second.MarkDirty();
     }
 }
 
 void CWallet::SetUsedDestinationState(const TxId &hash, unsigned int n,
                                       bool used) {
     const CWalletTx *srctx = GetWalletTx(hash);
     if (!srctx) {
         return;
     }
 
     CTxDestination dst;
     if (ExtractDestination(srctx->tx->vout[n].scriptPubKey, dst)) {
         if (IsMine(dst)) {
             LOCK(cs_wallet);
             if (used && !GetDestData(dst, "used", nullptr)) {
                 // p for "present", opposite of absent (null)
                 AddDestData(dst, "used", "p");
             } else if (!used && GetDestData(dst, "used", nullptr)) {
                 EraseDestData(dst, "used");
             }
         }
     }
 }
 
 bool CWallet::IsUsedDestination(const CTxDestination &dst) const {
     LOCK(cs_wallet);
     return IsMine(dst) && GetDestData(dst, "used", nullptr);
 }
 
 bool CWallet::IsUsedDestination(const TxId &txid, unsigned int n) const {
     CTxDestination dst;
     const CWalletTx *srctx = GetWalletTx(txid);
     return srctx && ExtractDestination(srctx->tx->vout[n].scriptPubKey, dst) &&
            IsUsedDestination(dst);
 }
 
 bool CWallet::AddToWallet(const CWalletTx &wtxIn, bool fFlushOnClose) {
     LOCK(cs_wallet);
 
     WalletBatch batch(*database, "r+", fFlushOnClose);
 
     const TxId &txid = wtxIn.GetId();
 
     if (IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE)) {
         // Mark used destinations
         for (const CTxIn &txin : wtxIn.tx->vin) {
             const COutPoint &op = txin.prevout;
             SetUsedDestinationState(op.GetTxId(), op.GetN(), true);
         }
     }
 
     // Inserts only if not already there, returns tx inserted or tx found.
     std::pair<std::map<TxId, CWalletTx>::iterator, bool> ret =
         mapWallet.insert(std::make_pair(txid, wtxIn));
     CWalletTx &wtx = (*ret.first).second;
     wtx.BindWallet(this);
     bool fInsertedNew = ret.second;
     if (fInsertedNew) {
         wtx.nTimeReceived = chain().getAdjustedTime();
         wtx.nOrderPos = IncOrderPosNext(&batch);
         wtx.m_it_wtxOrdered =
             wtxOrdered.insert(std::make_pair(wtx.nOrderPos, &wtx));
         wtx.nTimeSmart = ComputeTimeSmart(wtx);
         AddToSpends(txid);
     }
 
     bool fUpdated = false;
     if (!fInsertedNew) {
         if (wtxIn.m_confirm.status != wtx.m_confirm.status) {
             wtx.m_confirm.status = wtxIn.m_confirm.status;
             wtx.m_confirm.nIndex = wtxIn.m_confirm.nIndex;
             wtx.m_confirm.hashBlock = wtxIn.m_confirm.hashBlock;
             fUpdated = true;
         } else {
             assert(wtx.m_confirm.nIndex == wtxIn.m_confirm.nIndex);
             assert(wtx.m_confirm.hashBlock == wtxIn.m_confirm.hashBlock);
         }
 
         if (wtxIn.fFromMe && wtxIn.fFromMe != wtx.fFromMe) {
             wtx.fFromMe = wtxIn.fFromMe;
             fUpdated = true;
         }
     }
 
     //// debug print
     WalletLogPrintf("AddToWallet %s  %s%s\n", wtxIn.GetId().ToString(),
                     (fInsertedNew ? "new" : ""), (fUpdated ? "update" : ""));
 
     // Write to disk
     if ((fInsertedNew || fUpdated) && !batch.WriteTx(wtx)) {
         return false;
     }
 
     // Break debit/credit balance caches:
     wtx.MarkDirty();
 
     // Notify UI of new or updated transaction.
     NotifyTransactionChanged(this, txid, fInsertedNew ? CT_NEW : CT_UPDATED);
 
 #if defined(HAVE_SYSTEM)
     // Notify an external script when a wallet transaction comes in or is
     // updated.
     std::string strCmd = gArgs.GetArg("-walletnotify", "");
 
     if (!strCmd.empty()) {
         boost::replace_all(strCmd, "%s", wtxIn.GetId().GetHex());
         std::thread t(runCommand, strCmd);
         // Thread runs free.
         t.detach();
     }
 #endif
 
     return true;
 }
 
 void CWallet::LoadToWallet(CWalletTx &wtxIn) {
     // If wallet doesn't have a chain (e.g wallet-tool), lock can't be taken.
     auto locked_chain = LockChain();
     // If tx hasn't been reorged out of chain while wallet being shutdown
     // change tx status to UNCONFIRMED and reset hashBlock/nIndex.
     if (!wtxIn.m_confirm.hashBlock.IsNull()) {
         if (locked_chain &&
             !locked_chain->getBlockHeight(wtxIn.m_confirm.hashBlock)) {
             wtxIn.setUnconfirmed();
             wtxIn.m_confirm.hashBlock = BlockHash();
             wtxIn.m_confirm.nIndex = 0;
         }
     }
     const TxId &txid = wtxIn.GetId();
     const auto &ins = mapWallet.emplace(txid, wtxIn);
     CWalletTx &wtx = ins.first->second;
     wtx.BindWallet(this);
     if (/* insertion took place */ ins.second) {
         wtx.m_it_wtxOrdered =
             wtxOrdered.insert(std::make_pair(wtx.nOrderPos, &wtx));
     }
     AddToSpends(txid);
     for (const CTxIn &txin : wtx.tx->vin) {
         auto it = mapWallet.find(txin.prevout.GetTxId());
         if (it != mapWallet.end()) {
             CWalletTx &prevtx = it->second;
             if (prevtx.isConflicted()) {
                 MarkConflicted(prevtx.m_confirm.hashBlock, wtx.GetId());
             }
         }
     }
 }
 
 bool CWallet::AddToWalletIfInvolvingMe(const CTransactionRef &ptx,
                                        CWalletTx::Status status,
                                        const BlockHash &block_hash,
                                        int posInBlock, bool fUpdate) {
     const CTransaction &tx = *ptx;
     AssertLockHeld(cs_wallet);
 
     if (!block_hash.IsNull()) {
         for (const CTxIn &txin : tx.vin) {
             std::pair<TxSpends::const_iterator, TxSpends::const_iterator>
                 range = mapTxSpends.equal_range(txin.prevout);
             while (range.first != range.second) {
                 if (range.first->second != tx.GetId()) {
                     WalletLogPrintf(
                         "Transaction %s (in block %s) conflicts with wallet "
                         "transaction %s (both spend %s:%i)\n",
                         tx.GetId().ToString(), block_hash.ToString(),
                         range.first->second.ToString(),
                         range.first->first.GetTxId().ToString(),
                         range.first->first.GetN());
                     MarkConflicted(block_hash, range.first->second);
                 }
                 range.first++;
             }
         }
     }
 
     bool fExisted = mapWallet.count(tx.GetId()) != 0;
     if (fExisted && !fUpdate) {
         return false;
     }
     if (fExisted || IsMine(tx) || IsFromMe(tx)) {
         /**
          * Check if any keys in the wallet keypool that were supposed to be
          * unused have appeared in a new transaction. If so, remove those keys
          * from the keypool. This can happen when restoring an old wallet backup
          * that does not contain the mostly recently created transactions from
          * newer versions of the wallet.
          */
 
         // loop though all outputs
         for (const CTxOut &txout : tx.vout) {
             if (auto spk_man = m_spk_man.get()) {
                 spk_man->MarkUnusedAddresses(txout.scriptPubKey);
             }
         }
 
         CWalletTx wtx(this, ptx);
 
         // Block disconnection override an abandoned tx as unconfirmed
         // which means user may have to call abandontransaction again
         wtx.SetConf(status, block_hash, posInBlock);
 
         return AddToWallet(wtx, false);
     }
 
     return false;
 }
 
 bool CWallet::TransactionCanBeAbandoned(const TxId &txid) const {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
     const CWalletTx *wtx = GetWalletTx(txid);
     return wtx && !wtx->isAbandoned() &&
            wtx->GetDepthInMainChain(*locked_chain) == 0 && !wtx->InMempool();
 }
 
 void CWallet::MarkInputsDirty(const CTransactionRef &tx) {
     for (const CTxIn &txin : tx->vin) {
         auto it = mapWallet.find(txin.prevout.GetTxId());
         if (it != mapWallet.end()) {
             it->second.MarkDirty();
         }
     }
 }
 
 bool CWallet::AbandonTransaction(interfaces::Chain::Lock &locked_chain,
                                  const TxId &txid) {
     // Temporary. Removed in upcoming lock cleanup
     auto locked_chain_recursive = chain().lock();
     LOCK(cs_wallet);
 
     WalletBatch batch(*database, "r+");
 
     std::set<TxId> todo;
     std::set<TxId> done;
 
     // Can't mark abandoned if confirmed or in mempool
     auto it = mapWallet.find(txid);
     assert(it != mapWallet.end());
     CWalletTx &origtx = it->second;
     if (origtx.GetDepthInMainChain(locked_chain) != 0 || origtx.InMempool()) {
         return false;
     }
 
     todo.insert(txid);
 
     while (!todo.empty()) {
         const TxId now = *todo.begin();
         todo.erase(now);
         done.insert(now);
         it = mapWallet.find(now);
         assert(it != mapWallet.end());
         CWalletTx &wtx = it->second;
         int currentconfirm = wtx.GetDepthInMainChain(locked_chain);
         // If the orig tx was not in block, none of its spends can be.
         assert(currentconfirm <= 0);
         // If (currentconfirm < 0) {Tx and spends are already conflicted, no
         // need to abandon}
         if (currentconfirm == 0 && !wtx.isAbandoned()) {
             // If the orig tx was not in block/mempool, none of its spends can
             // be in mempool.
             assert(!wtx.InMempool());
             wtx.m_confirm.nIndex = 0;
             wtx.setAbandoned();
             wtx.MarkDirty();
             batch.WriteTx(wtx);
             NotifyTransactionChanged(this, wtx.GetId(), CT_UPDATED);
             // Iterate over all its outputs, and mark transactions in the wallet
             // that spend them abandoned too.
             TxSpends::const_iterator iter =
                 mapTxSpends.lower_bound(COutPoint(now, 0));
             while (iter != mapTxSpends.end() && iter->first.GetTxId() == now) {
                 if (!done.count(iter->second)) {
                     todo.insert(iter->second);
                 }
                 iter++;
             }
 
             // If a transaction changes 'conflicted' state, that changes the
             // balance available of the outputs it spends. So force those to be
             // recomputed.
             MarkInputsDirty(wtx.tx);
         }
     }
 
     return true;
 }
 
 void CWallet::MarkConflicted(const BlockHash &hashBlock, const TxId &txid) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     int conflictconfirms = -locked_chain->getBlockDepth(hashBlock);
 
     // If number of conflict confirms cannot be determined, this means that the
     // block is still unknown or not yet part of the main chain, for example
     // when loading the wallet during a reindex. Do nothing in that case.
     if (conflictconfirms >= 0) {
         return;
     }
 
     // Do not flush the wallet here for performance reasons.
     WalletBatch batch(*database, "r+", false);
 
     std::set<TxId> todo;
     std::set<TxId> done;
 
     todo.insert(txid);
 
     while (!todo.empty()) {
         const TxId now = *todo.begin();
         todo.erase(now);
         done.insert(now);
         auto it = mapWallet.find(now);
         assert(it != mapWallet.end());
         CWalletTx &wtx = it->second;
         int currentconfirm = wtx.GetDepthInMainChain(*locked_chain);
         if (conflictconfirms < currentconfirm) {
             // Block is 'more conflicted' than current confirm; update.
             // Mark transaction as conflicted with this block.
             wtx.m_confirm.nIndex = 0;
             wtx.m_confirm.hashBlock = hashBlock;
             wtx.setConflicted();
             wtx.MarkDirty();
             batch.WriteTx(wtx);
             // Iterate over all its outputs, and mark transactions in the wallet
             // that spend them conflicted too.
             TxSpends::const_iterator iter =
                 mapTxSpends.lower_bound(COutPoint(now, 0));
             while (iter != mapTxSpends.end() && iter->first.GetTxId() == now) {
                 if (!done.count(iter->second)) {
                     todo.insert(iter->second);
                 }
                 iter++;
             }
             // If a transaction changes 'conflicted' state, that changes the
             // balance available of the outputs it spends. So force those to be
             // recomputed.
             MarkInputsDirty(wtx.tx);
         }
     }
 }
 
 void CWallet::SyncTransaction(const CTransactionRef &ptx,
                               CWalletTx::Status status,
                               const BlockHash &block_hash, int posInBlock,
                               bool update_tx) {
     if (!AddToWalletIfInvolvingMe(ptx, status, block_hash, posInBlock,
                                   update_tx)) {
         // Not one of ours
         return;
     }
 
     // If a transaction changes 'conflicted' state, that changes the balance
     // available of the outputs it spends. So force those to be
     // recomputed, also:
     MarkInputsDirty(ptx);
 }
 
 void CWallet::TransactionAddedToMempool(const CTransactionRef &ptx) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
     SyncTransaction(ptx, CWalletTx::Status::UNCONFIRMED,
                     BlockHash() /* block hash */, 0 /* position in block */);
 
     auto it = mapWallet.find(ptx->GetId());
     if (it != mapWallet.end()) {
         it->second.fInMempool = true;
     }
 }
 
 void CWallet::TransactionRemovedFromMempool(const CTransactionRef &ptx) {
     LOCK(cs_wallet);
     auto it = mapWallet.find(ptx->GetId());
     if (it != mapWallet.end()) {
         it->second.fInMempool = false;
     }
 }
 
 void CWallet::BlockConnected(const CBlock &block,
                              const std::vector<CTransactionRef> &vtxConflicted,
                              int height) {
     const BlockHash &block_hash = block.GetHash();
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
+    m_last_block_processed_height = height;
+    m_last_block_processed = block_hash;
     for (size_t i = 0; i < block.vtx.size(); i++) {
         SyncTransaction(block.vtx[i], CWalletTx::Status::CONFIRMED, block_hash,
                         i);
         TransactionRemovedFromMempool(block.vtx[i]);
     }
     for (const CTransactionRef &ptx : vtxConflicted) {
         TransactionRemovedFromMempool(ptx);
     }
-
-    m_last_block_processed = block_hash;
 }
 
 void CWallet::BlockDisconnected(const CBlock &block, int height) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     // At block disconnection, this will change an abandoned transaction to
     // be unconfirmed, whether or not the transaction is added back to the
     // mempool. User may have to call abandontransaction again. It may be
     // addressed in the future with a stickier abandoned state or even removing
     // abandontransaction call.
+    m_last_block_processed_height = height - 1;
+    m_last_block_processed = block.hashPrevBlock;
     for (const CTransactionRef &ptx : block.vtx) {
         SyncTransaction(ptx, CWalletTx::Status::UNCONFIRMED,
                         BlockHash() /* block hash */,
                         0 /* position in block */);
     }
 }
 
 void CWallet::UpdatedBlockTip() {
     m_best_block_time = GetTime();
 }
 
 void CWallet::BlockUntilSyncedToCurrentChain() {
     AssertLockNotHeld(cs_wallet);
     // Skip the queue-draining stuff if we know we're caught up with
     // chainActive.Tip(), otherwise put a callback in the validation interface
     // queue and wait for the queue to drain enough to execute it (indicating we
     // are caught up at least with the time we entered this function).
     const BlockHash last_block_hash =
         WITH_LOCK(cs_wallet, return m_last_block_processed);
     chain().waitForNotificationsIfNewBlocksConnected(last_block_hash);
 }
 
 isminetype CWallet::IsMine(const CTxIn &txin) const {
     LOCK(cs_wallet);
     std::map<TxId, CWalletTx>::const_iterator mi =
         mapWallet.find(txin.prevout.GetTxId());
     if (mi != mapWallet.end()) {
         const CWalletTx &prev = (*mi).second;
         if (txin.prevout.GetN() < prev.tx->vout.size()) {
             return IsMine(prev.tx->vout[txin.prevout.GetN()]);
         }
     }
 
     return ISMINE_NO;
 }
 
 // Note that this function doesn't distinguish between a 0-valued input, and a
 // not-"is mine" (according to the filter) input.
 Amount CWallet::GetDebit(const CTxIn &txin, const isminefilter &filter) const {
     LOCK(cs_wallet);
     std::map<TxId, CWalletTx>::const_iterator mi =
         mapWallet.find(txin.prevout.GetTxId());
     if (mi != mapWallet.end()) {
         const CWalletTx &prev = (*mi).second;
         if (txin.prevout.GetN() < prev.tx->vout.size()) {
             if (IsMine(prev.tx->vout[txin.prevout.GetN()]) & filter) {
                 return prev.tx->vout[txin.prevout.GetN()].nValue;
             }
         }
     }
 
     return Amount::zero();
 }
 
 isminetype CWallet::IsMine(const CTxOut &txout) const {
     return IsMine(txout.scriptPubKey);
 }
 
 isminetype CWallet::IsMine(const CTxDestination &dest) const {
     return IsMine(GetScriptForDestination(dest));
 }
 
 isminetype CWallet::IsMine(const CScript &script) const {
     isminetype result = ISMINE_NO;
     if (auto spk_man = m_spk_man.get()) {
         result = spk_man->IsMine(script);
     }
     return result;
 }
 
 Amount CWallet::GetCredit(const CTxOut &txout,
                           const isminefilter &filter) const {
     if (!MoneyRange(txout.nValue)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": value out of range");
     }
 
     return (IsMine(txout) & filter) ? txout.nValue : Amount::zero();
 }
 
 bool CWallet::IsChange(const CTxOut &txout) const {
     return IsChange(txout.scriptPubKey);
 }
 
 bool CWallet::IsChange(const CScript &script) const {
     // TODO: fix handling of 'change' outputs. The assumption is that any
     // payment to a script that is ours, but is not in the address book is
     // change. That assumption is likely to break when we implement
     // multisignature wallets that return change back into a
     // multi-signature-protected address; a better way of identifying which
     // outputs are 'the send' and which are 'the change' will need to be
     // implemented (maybe extend CWalletTx to remember which output, if any, was
     // change).
     if (IsMine(script)) {
         CTxDestination address;
         if (!ExtractDestination(script, address)) {
             return true;
         }
 
         LOCK(cs_wallet);
         if (!mapAddressBook.count(address)) {
             return true;
         }
     }
 
     return false;
 }
 
 Amount CWallet::GetChange(const CTxOut &txout) const {
     if (!MoneyRange(txout.nValue)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": value out of range");
     }
 
     return (IsChange(txout) ? txout.nValue : Amount::zero());
 }
 
 bool CWallet::IsMine(const CTransaction &tx) const {
     for (const CTxOut &txout : tx.vout) {
         if (IsMine(txout)) {
             return true;
         }
     }
 
     return false;
 }
 
 bool CWallet::IsFromMe(const CTransaction &tx) const {
     return GetDebit(tx, ISMINE_ALL) > Amount::zero();
 }
 
 Amount CWallet::GetDebit(const CTransaction &tx,
                          const isminefilter &filter) const {
     Amount nDebit = Amount::zero();
     for (const CTxIn &txin : tx.vin) {
         nDebit += GetDebit(txin, filter);
         if (!MoneyRange(nDebit)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": value out of range");
         }
     }
 
     return nDebit;
 }
 
 bool CWallet::IsAllFromMe(const CTransaction &tx,
                           const isminefilter &filter) const {
     LOCK(cs_wallet);
 
     for (const CTxIn &txin : tx.vin) {
         auto mi = mapWallet.find(txin.prevout.GetTxId());
         if (mi == mapWallet.end()) {
             // Any unknown inputs can't be from us.
             return false;
         }
 
         const CWalletTx &prev = (*mi).second;
 
         if (txin.prevout.GetN() >= prev.tx->vout.size()) {
             // Invalid input!
             return false;
         }
 
         if (!(IsMine(prev.tx->vout[txin.prevout.GetN()]) & filter)) {
             return false;
         }
     }
 
     return true;
 }
 
 Amount CWallet::GetCredit(const CTransaction &tx,
                           const isminefilter &filter) const {
     Amount nCredit = Amount::zero();
     for (const CTxOut &txout : tx.vout) {
         nCredit += GetCredit(txout, filter);
         if (!MoneyRange(nCredit)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": value out of range");
         }
     }
 
     return nCredit;
 }
 
 Amount CWallet::GetChange(const CTransaction &tx) const {
     Amount nChange = Amount::zero();
     for (const CTxOut &txout : tx.vout) {
         nChange += GetChange(txout);
         if (!MoneyRange(nChange)) {
             throw std::runtime_error(std::string(__func__) +
                                      ": value out of range");
         }
     }
 
     return nChange;
 }
 
 bool CWallet::IsHDEnabled() const {
     bool result = true;
     if (auto spk_man = m_spk_man.get()) {
         result &= spk_man->IsHDEnabled();
     }
     return result;
 }
 
 bool CWallet::CanGetAddresses(bool internal) {
     {
         auto spk_man = m_spk_man.get();
         if (spk_man && spk_man->CanGetAddresses(internal)) {
             return true;
         }
     }
     return false;
 }
 
 void CWallet::SetWalletFlag(uint64_t flags) {
     LOCK(cs_wallet);
     m_wallet_flags |= flags;
     if (!WalletBatch(*database).WriteWalletFlags(m_wallet_flags)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing wallet flags failed");
     }
 }
 
 void CWallet::UnsetWalletFlag(uint64_t flag) {
     WalletBatch batch(*database);
     UnsetWalletFlagWithDB(batch, flag);
 }
 
 void CWallet::UnsetWalletFlagWithDB(WalletBatch &batch, uint64_t flag) {
     LOCK(cs_wallet);
     m_wallet_flags &= ~flag;
     if (!batch.WriteWalletFlags(m_wallet_flags)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing wallet flags failed");
     }
 }
 
 void CWallet::UnsetBlankWalletFlag(WalletBatch &batch) {
     UnsetWalletFlagWithDB(batch, WALLET_FLAG_BLANK_WALLET);
 }
 
 bool CWallet::IsWalletFlagSet(uint64_t flag) const {
     return (m_wallet_flags & flag);
 }
 
 bool CWallet::SetWalletFlags(uint64_t overwriteFlags, bool memonly) {
     LOCK(cs_wallet);
     m_wallet_flags = overwriteFlags;
     if (((overwriteFlags & KNOWN_WALLET_FLAGS) >> 32) ^
         (overwriteFlags >> 32)) {
         // contains unknown non-tolerable wallet flags
         return false;
     }
     if (!memonly && !WalletBatch(*database).WriteWalletFlags(m_wallet_flags)) {
         throw std::runtime_error(std::string(__func__) +
                                  ": writing wallet flags failed");
     }
 
     return true;
 }
 
 int64_t CWalletTx::GetTxTime() const {
     int64_t n = nTimeSmart;
     return n ? n : nTimeReceived;
 }
 
 // Helper for producing a max-sized low-S low-R signature (eg 71 bytes)
 // or a max-sized low-S signature (e.g. 72 bytes) if use_max_sig is true
 bool CWallet::DummySignInput(CTxIn &tx_in, const CTxOut &txout,
                              bool use_max_sig) const {
     // Fill in dummy signatures for fee calculation.
     const CScript &scriptPubKey = txout.scriptPubKey;
     SignatureData sigdata;
 
     const SigningProvider *provider = GetSigningProvider();
 
     if (!ProduceSignature(*provider,
                           use_max_sig ? DUMMY_MAXIMUM_SIGNATURE_CREATOR
                                       : DUMMY_SIGNATURE_CREATOR,
                           scriptPubKey, sigdata)) {
         return false;
     }
 
     UpdateInput(tx_in, sigdata);
     return true;
 }
 
 // Helper for producing a bunch of max-sized low-S low-R signatures (eg 71
 // bytes)
 bool CWallet::DummySignTx(CMutableTransaction &txNew,
                           const std::vector<CTxOut> &txouts,
                           bool use_max_sig) const {
     // Fill in dummy signatures for fee calculation.
     int nIn = 0;
     for (const auto &txout : txouts) {
         if (!DummySignInput(txNew.vin[nIn], txout, use_max_sig)) {
             return false;
         }
 
         nIn++;
     }
     return true;
 }
 
 bool CWallet::ImportScripts(const std::set<CScript> scripts,
                             int64_t timestamp) {
     auto spk_man = GetLegacyScriptPubKeyMan();
     if (!spk_man) {
         return false;
     }
     AssertLockHeld(spk_man->cs_wallet);
     return spk_man->ImportScripts(scripts, timestamp);
 }
 
 bool CWallet::ImportPrivKeys(const std::map<CKeyID, CKey> &privkey_map,
                              const int64_t timestamp) {
     auto spk_man = GetLegacyScriptPubKeyMan();
     if (!spk_man) {
         return false;
     }
     AssertLockHeld(spk_man->cs_wallet);
     return spk_man->ImportPrivKeys(privkey_map, timestamp);
 }
 
 bool CWallet::ImportPubKeys(
     const std::vector<CKeyID> &ordered_pubkeys,
     const std::map<CKeyID, CPubKey> &pubkey_map,
     const std::map<CKeyID, std::pair<CPubKey, KeyOriginInfo>> &key_origins,
     const bool add_keypool, const bool internal, const int64_t timestamp) {
     auto spk_man = GetLegacyScriptPubKeyMan();
     if (!spk_man) {
         return false;
     }
     AssertLockHeld(spk_man->cs_wallet);
     return spk_man->ImportPubKeys(ordered_pubkeys, pubkey_map, key_origins,
                                   add_keypool, internal, timestamp);
 }
 
 bool CWallet::ImportScriptPubKeys(const std::string &label,
                                   const std::set<CScript> &script_pub_keys,
                                   const bool have_solving_data,
                                   const bool apply_label,
                                   const int64_t timestamp) {
     auto spk_man = GetLegacyScriptPubKeyMan();
     if (!spk_man) {
         return false;
     }
     AssertLockHeld(spk_man->cs_wallet);
     if (!spk_man->ImportScriptPubKeys(script_pub_keys, have_solving_data,
                                       timestamp)) {
         return false;
     }
     if (apply_label) {
         WalletBatch batch(*database);
         for (const CScript &script : script_pub_keys) {
             CTxDestination dest;
             ExtractDestination(script, dest);
             if (IsValidDestination(dest)) {
                 SetAddressBookWithDB(batch, dest, label, "receive");
             }
         }
     }
     return true;
 }
 
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet, bool use_max_sig) {
     std::vector<CTxOut> txouts;
     // Look up the inputs.  We should have already checked that this transaction
     // IsAllFromMe(ISMINE_SPENDABLE), so every input should already be in our
     // wallet, with a valid index into the vout array, and the ability to sign.
     for (auto &input : tx.vin) {
         const auto mi = wallet->mapWallet.find(input.prevout.GetTxId());
         if (mi == wallet->mapWallet.end()) {
             return -1;
         }
         assert(input.prevout.GetN() < mi->second.tx->vout.size());
         txouts.emplace_back(mi->second.tx->vout[input.prevout.GetN()]);
     }
     return CalculateMaximumSignedTxSize(tx, wallet, txouts, use_max_sig);
 }
 
 // txouts needs to be in the order of tx.vin
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet,
                                      const std::vector<CTxOut> &txouts,
                                      bool use_max_sig) {
     CMutableTransaction txNew(tx);
     if (!wallet->DummySignTx(txNew, txouts, use_max_sig)) {
         // This should never happen, because IsAllFromMe(ISMINE_SPENDABLE)
         // implies that we can sign for every input.
         return -1;
     }
     return GetSerializeSize(txNew, PROTOCOL_VERSION);
 }
 
 int CalculateMaximumSignedInputSize(const CTxOut &txout, const CWallet *wallet,
                                     bool use_max_sig) {
     CMutableTransaction txn;
     txn.vin.push_back(CTxIn(COutPoint()));
     if (!wallet->DummySignInput(txn.vin[0], txout, use_max_sig)) {
         // This should never happen, because IsAllFromMe(ISMINE_SPENDABLE)
         // implies that we can sign for every input.
         return -1;
     }
     return GetSerializeSize(txn.vin[0], PROTOCOL_VERSION);
 }
 
 void CWalletTx::GetAmounts(std::list<COutputEntry> &listReceived,
                            std::list<COutputEntry> &listSent, Amount &nFee,
                            const isminefilter &filter) const {
     nFee = Amount::zero();
     listReceived.clear();
     listSent.clear();
 
     // Compute fee:
     Amount nDebit = GetDebit(filter);
     // debit>0 means we signed/sent this transaction.
     if (nDebit > Amount::zero()) {
         Amount nValueOut = tx->GetValueOut();
         nFee = (nDebit - nValueOut);
     }
 
     // Sent/received.
     for (unsigned int i = 0; i < tx->vout.size(); ++i) {
         const CTxOut &txout = tx->vout[i];
         isminetype fIsMine = pwallet->IsMine(txout);
         // Only need to handle txouts if AT LEAST one of these is true:
         //   1) they debit from us (sent)
         //   2) the output is to us (received)
         if (nDebit > Amount::zero()) {
             // Don't report 'change' txouts
             if (pwallet->IsChange(txout)) {
                 continue;
             }
         } else if (!(fIsMine & filter)) {
             continue;
         }
 
         // In either case, we need to get the destination address.
         CTxDestination address;
 
         if (!ExtractDestination(txout.scriptPubKey, address) &&
             !txout.scriptPubKey.IsUnspendable()) {
             pwallet->WalletLogPrintf("CWalletTx::GetAmounts: Unknown "
                                      "transaction type found, txid %s\n",
                                      this->GetId().ToString());
             address = CNoDestination();
         }
 
         COutputEntry output = {address, txout.nValue, (int)i};
 
         // If we are debited by the transaction, add the output as a "sent"
         // entry.
         if (nDebit > Amount::zero()) {
             listSent.push_back(output);
         }
 
         // If we are receiving the output, add it as a "received" entry.
         if (fIsMine & filter) {
             listReceived.push_back(output);
         }
     }
 }
 
 /**
  * Scan active chain for relevant transactions after importing keys. This should
  * be called whenever new keys are added to the wallet, with the oldest key
  * creation time.
  *
  * @return Earliest timestamp that could be successfully scanned from. Timestamp
  * returned will be higher than startTime if relevant blocks could not be read.
  */
 int64_t CWallet::RescanFromTime(int64_t startTime,
                                 const WalletRescanReserver &reserver,
                                 bool update) {
     // Find starting block. May be null if nCreateTime is greater than the
     // highest blockchain timestamp, in which case there is nothing that needs
     // to be scanned.
     BlockHash start_block;
     {
         auto locked_chain = chain().lock();
         const Optional<int> start_height =
             locked_chain->findFirstBlockWithTimeAndHeight(
                 startTime - TIMESTAMP_WINDOW, 0, &start_block);
         const Optional<int> tip_height = locked_chain->getHeight();
         WalletLogPrintf(
             "%s: Rescanning last %i blocks\n", __func__,
             tip_height && start_height ? *tip_height - *start_height + 1 : 0);
     }
 
     if (!start_block.IsNull()) {
         // TODO: this should take into account failure by ScanResult::USER_ABORT
         ScanResult result = ScanForWalletTransactions(start_block, BlockHash(),
                                                       reserver, update);
         if (result.status == ScanResult::FAILURE) {
             int64_t time_max;
             if (!chain().findBlock(result.last_failed_block,
                                    nullptr /* block */, nullptr /* time */,
                                    &time_max)) {
                 throw std::logic_error(
                     "ScanForWalletTransactions returned invalid block hash");
             }
             return time_max + TIMESTAMP_WINDOW + 1;
         }
     }
     return startTime;
 }
 
 /**
  * Scan the block chain (starting in start_block) for transactions from or to
  * us. If fUpdate is true, found transactions that already exist in the wallet
  * will be updated.
  *
  * @param[in] start_block Scan starting block. If block is not on the active
  *                        chain, the scan will return SUCCESS immediately.
  * @param[in] stop_block  Scan ending block. If block is not on the active
  *                        chain, the scan will continue until it reaches the
  *                        chain tip.
  *
  * @return ScanResult returning scan information and indicating success or
  *         failure. Return status will be set to SUCCESS if scan was
  *         successful. FAILURE if a complete rescan was not possible (due to
  *         pruning or corruption). USER_ABORT if the rescan was aborted before
  *         it could complete.
  *
  * @pre Caller needs to make sure start_block (and the optional stop_block) are
  * on the main chain after to the addition of any new keys you want to detect
  * transactions for.
  */
 CWallet::ScanResult CWallet::ScanForWalletTransactions(
     const BlockHash &start_block, const BlockHash &stop_block,
     const WalletRescanReserver &reserver, bool fUpdate) {
     int64_t nNow = GetTime();
     int64_t start_time = GetTimeMillis();
 
     assert(reserver.isReserved());
 
     BlockHash block_hash = start_block;
     ScanResult result;
 
     WalletLogPrintf("Rescan started from block %s...\n",
                     start_block.ToString());
 
     fAbortRescan = false;
 
     // Show rescan progress in GUI as dialog or on splashscreen, if -rescan
     // on startup.
     ShowProgress(
         strprintf("%s " + _("Rescanning...").translated, GetDisplayName()), 0);
     BlockHash tip_hash;
     // The way the 'block_height' is initialized is just a workaround for
     // the gcc bug #47679 since version 4.6.0.
     Optional<int> block_height = MakeOptional(false, int());
     double progress_begin;
     double progress_end;
     {
         auto locked_chain = chain().lock();
         if (Optional<int> tip_height = locked_chain->getHeight()) {
             tip_hash = locked_chain->getBlockHash(*tip_height);
         }
         block_height = locked_chain->getBlockHeight(block_hash);
         progress_begin = chain().guessVerificationProgress(block_hash);
         progress_end = chain().guessVerificationProgress(
             stop_block.IsNull() ? tip_hash : stop_block);
     }
     double progress_current = progress_begin;
     while (block_height && !fAbortRescan && !chain().shutdownRequested()) {
         m_scanning_progress = (progress_current - progress_begin) /
                               (progress_end - progress_begin);
         if (*block_height % 100 == 0 && progress_end - progress_begin > 0.0) {
             ShowProgress(
                 strprintf("%s " + _("Rescanning...").translated,
                           GetDisplayName()),
                 std::max(1, std::min(99, int(m_scanning_progress * 100))));
         }
         if (GetTime() >= nNow + 60) {
             nNow = GetTime();
             WalletLogPrintf("Still rescanning. At block %d. Progress=%f\n",
                             *block_height, progress_current);
         }
 
         CBlock block;
         if (chain().findBlock(block_hash, &block) && !block.IsNull()) {
             auto locked_chain = chain().lock();
             LOCK(cs_wallet);
             if (!locked_chain->getBlockHeight(block_hash)) {
                 // Abort scan if current block is no longer active, to
                 // prevent marking transactions as coming from the wrong
                 // block.
                 // TODO: This should return success instead of failure, see
                 // https://github.com/bitcoin/bitcoin/pull/14711#issuecomment-458342518
                 result.last_failed_block = block_hash;
                 result.status = ScanResult::FAILURE;
                 break;
             }
             for (size_t posInBlock = 0; posInBlock < block.vtx.size();
                  ++posInBlock) {
                 SyncTransaction(block.vtx[posInBlock],
                                 CWalletTx::Status::CONFIRMED, block_hash,
                                 posInBlock, fUpdate);
             }
             // scan succeeded, record block as most recent successfully
             // scanned
             result.last_scanned_block = block_hash;
             result.last_scanned_height = *block_height;
         } else {
             // could not scan block, keep scanning but record this block as
             // the most recent failure
             result.last_failed_block = block_hash;
             result.status = ScanResult::FAILURE;
         }
         if (block_hash == stop_block) {
             break;
         }
         {
             auto locked_chain = chain().lock();
             Optional<int> tip_height = locked_chain->getHeight();
             if (!tip_height || *tip_height <= block_height ||
                 !locked_chain->getBlockHeight(block_hash)) {
                 // break successfully when rescan has reached the tip, or
                 // previous block is no longer on the chain due to a reorg
                 break;
             }
 
             // increment block and verification progress
             block_hash = locked_chain->getBlockHash(++*block_height);
             progress_current = chain().guessVerificationProgress(block_hash);
 
             // handle updated tip hash
             const BlockHash prev_tip_hash = tip_hash;
             tip_hash = locked_chain->getBlockHash(*tip_height);
             if (stop_block.IsNull() && prev_tip_hash != tip_hash) {
                 // in case the tip has changed, update progress max
                 progress_end = chain().guessVerificationProgress(tip_hash);
             }
         }
     }
 
     // Hide progress dialog in GUI.
     ShowProgress(
         strprintf("%s " + _("Rescanning...").translated, GetDisplayName()),
         100);
     if (block_height && fAbortRescan) {
         WalletLogPrintf("Rescan aborted at block %d. Progress=%f\n",
                         *block_height, progress_current);
         result.status = ScanResult::USER_ABORT;
     } else if (block_height && chain().shutdownRequested()) {
         WalletLogPrintf("Rescan interrupted by shutdown request at block "
                         "%d. Progress=%f\n",
                         *block_height, progress_current);
         result.status = ScanResult::USER_ABORT;
     } else {
         WalletLogPrintf("Rescan completed in %15dms\n",
                         GetTimeMillis() - start_time);
     }
     return result;
 }
 
 void CWallet::ReacceptWalletTransactions(
     interfaces::Chain::Lock &locked_chain) {
     // If transactions aren't being broadcasted, don't let them into local
     // mempool either.
     if (!fBroadcastTransactions) {
         return;
     }
 
     std::map<int64_t, CWalletTx *> mapSorted;
 
     // Sort pending wallet transactions based on their initial wallet insertion
     // order.
     for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
         const TxId &wtxid = item.first;
         CWalletTx &wtx = item.second;
         assert(wtx.GetId() == wtxid);
 
         int nDepth = wtx.GetDepthInMainChain(locked_chain);
 
         if (!wtx.IsCoinBase() && (nDepth == 0 && !wtx.isAbandoned())) {
             mapSorted.insert(std::make_pair(wtx.nOrderPos, &wtx));
         }
     }
 
     // Try to add wallet transactions to memory pool.
     for (const std::pair<const int64_t, CWalletTx *> &item : mapSorted) {
         CWalletTx &wtx = *(item.second);
         std::string unused_err_string;
         wtx.SubmitMemoryPoolAndRelay(unused_err_string, false, locked_chain);
     }
 }
 
 bool CWalletTx::SubmitMemoryPoolAndRelay(
     std::string &err_string, bool relay,
     interfaces::Chain::Lock &locked_chain) {
     // Can't relay if wallet is not broadcasting
     if (!pwallet->GetBroadcastTransactions()) {
         return false;
     }
     // Don't relay abandoned transactions
     if (isAbandoned()) {
         return false;
     }
     // Don't try to submit coinbase transactions. These would fail anyway but
     // would cause log spam.
     if (IsCoinBase()) {
         return false;
     }
     // Don't try to submit conflicted or confirmed transactions.
     if (GetDepthInMainChain(locked_chain) != 0) {
         return false;
     }
 
     // Submit transaction to mempool for relay
     pwallet->WalletLogPrintf("Submitting wtx %s to mempool for relay\n",
                              GetId().ToString());
     // We must set fInMempool here - while it will be re-set to true by the
     // entered-mempool callback, if we did not there would be a race where a
     // user could call sendmoney in a loop and hit spurious out of funds errors
     // because we think that this newly generated transaction's change is
     // unavailable as we're not yet aware that it is in the mempool.
     //
     // Irrespective of the failure reason, un-marking fInMempool
     // out-of-order is incorrect - it should be unmarked when
     // TransactionRemovedFromMempool fires.
     bool ret = pwallet->chain().broadcastTransaction(
         GetConfig(), tx, err_string, pwallet->m_default_max_tx_fee, relay);
     fInMempool |= ret;
     return ret;
 }
 
 std::set<TxId> CWalletTx::GetConflicts() const {
     std::set<TxId> result;
     if (pwallet != nullptr) {
         const TxId &txid = GetId();
         result = pwallet->GetConflicts(txid);
         result.erase(txid);
     }
 
     return result;
 }
 
 Amount CWalletTx::GetCachableAmount(AmountType type, const isminefilter &filter,
                                     bool recalculate) const {
     auto &amount = m_amounts[type];
     if (recalculate || !amount.m_cached[filter]) {
         amount.Set(filter, type == DEBIT ? pwallet->GetDebit(*tx, filter)
                                          : pwallet->GetCredit(*tx, filter));
     }
     return amount.m_value[filter];
 }
 
 Amount CWalletTx::GetDebit(const isminefilter &filter) const {
     if (tx->vin.empty()) {
         return Amount::zero();
     }
 
     Amount debit = Amount::zero();
     if (filter & ISMINE_SPENDABLE) {
         debit += GetCachableAmount(DEBIT, ISMINE_SPENDABLE);
     }
     if (filter & ISMINE_WATCH_ONLY) {
         debit += GetCachableAmount(DEBIT, ISMINE_WATCH_ONLY);
     }
 
     return debit;
 }
 
 Amount CWalletTx::GetCredit(interfaces::Chain::Lock &locked_chain,
                             const isminefilter &filter) const {
     // Must wait until coinbase is safely deep enough in the chain before
     // valuing it.
     if (IsImmatureCoinBase(locked_chain)) {
         return Amount::zero();
     }
 
     Amount credit = Amount::zero();
     if (filter & ISMINE_SPENDABLE) {
         // GetBalance can assume transactions in mapWallet won't change.
         credit += GetCachableAmount(CREDIT, ISMINE_SPENDABLE);
     }
 
     if (filter & ISMINE_WATCH_ONLY) {
         credit += GetCachableAmount(CREDIT, ISMINE_WATCH_ONLY);
     }
 
     return credit;
 }
 
 Amount CWalletTx::GetImmatureCredit(interfaces::Chain::Lock &locked_chain,
                                     bool fUseCache) const {
     if (IsImmatureCoinBase(locked_chain) && IsInMainChain(locked_chain)) {
         return GetCachableAmount(IMMATURE_CREDIT, ISMINE_SPENDABLE, !fUseCache);
     }
 
     return Amount::zero();
 }
 
 Amount CWalletTx::GetAvailableCredit(interfaces::Chain::Lock &locked_chain,
                                      bool fUseCache,
                                      const isminefilter &filter) const {
     if (pwallet == nullptr) {
         return Amount::zero();
     }
 
     // Avoid caching ismine for NO or ALL cases (could remove this check and
     // simplify in the future).
     bool allow_cache =
         (filter & ISMINE_ALL) && (filter & ISMINE_ALL) != ISMINE_ALL;
 
     // Must wait until coinbase is safely deep enough in the chain before
     // valuing it.
     if (IsImmatureCoinBase(locked_chain)) {
         return Amount::zero();
     }
 
     if (fUseCache && allow_cache &&
         m_amounts[AVAILABLE_CREDIT].m_cached[filter]) {
         return m_amounts[AVAILABLE_CREDIT].m_value[filter];
     }
 
     bool allow_used_addresses =
         (filter & ISMINE_USED) ||
         !pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
     Amount nCredit = Amount::zero();
     const TxId &txid = GetId();
     for (uint32_t i = 0; i < tx->vout.size(); i++) {
         if (!pwallet->IsSpent(locked_chain, COutPoint(txid, i)) &&
             (allow_used_addresses || !pwallet->IsUsedDestination(txid, i))) {
             const CTxOut &txout = tx->vout[i];
             nCredit += pwallet->GetCredit(txout, filter);
             if (!MoneyRange(nCredit)) {
                 throw std::runtime_error(std::string(__func__) +
                                          " : value out of range");
             }
         }
     }
 
     if (allow_cache) {
         m_amounts[AVAILABLE_CREDIT].Set(filter, nCredit);
     }
 
     return nCredit;
 }
 
 Amount
 CWalletTx::GetImmatureWatchOnlyCredit(interfaces::Chain::Lock &locked_chain,
                                       const bool fUseCache) const {
     if (IsImmatureCoinBase(locked_chain) && IsInMainChain(locked_chain)) {
         return GetCachableAmount(IMMATURE_CREDIT, ISMINE_WATCH_ONLY,
                                  !fUseCache);
     }
 
     return Amount::zero();
 }
 
 Amount CWalletTx::GetChange() const {
     if (fChangeCached) {
         return nChangeCached;
     }
 
     nChangeCached = pwallet->GetChange(*tx);
     fChangeCached = true;
     return nChangeCached;
 }
 
 bool CWalletTx::InMempool() const {
     return fInMempool;
 }
 
 bool CWalletTx::IsTrusted(interfaces::Chain::Lock &locked_chain) const {
     // Quick answer in most cases
     TxValidationState state;
     if (!locked_chain.contextualCheckTransactionForCurrentBlock(
             Params().GetConsensus(), *tx, state)) {
         return false;
     }
 
     int nDepth = GetDepthInMainChain(locked_chain);
     if (nDepth >= 1) {
         return true;
     }
 
     if (nDepth < 0) {
         return false;
     }
 
     // using wtx's cached debit
     if (!pwallet->m_spend_zero_conf_change || !IsFromMe(ISMINE_ALL)) {
         return false;
     }
 
     // Don't trust unconfirmed transactions from us unless they are in the
     // mempool.
     if (!InMempool()) {
         return false;
     }
 
     // Trusted if all inputs are from us and are in the mempool:
     for (const CTxIn &txin : tx->vin) {
         // Transactions not sent by us: not trusted
         const CWalletTx *parent = pwallet->GetWalletTx(txin.prevout.GetTxId());
         if (parent == nullptr) {
             return false;
         }
 
         const CTxOut &parentOut = parent->tx->vout[txin.prevout.GetN()];
         if (pwallet->IsMine(parentOut) != ISMINE_SPENDABLE) {
             return false;
         }
     }
 
     return true;
 }
 
 bool CWalletTx::IsEquivalentTo(const CWalletTx &_tx) const {
     CMutableTransaction tx1{*this->tx};
     CMutableTransaction tx2{*_tx.tx};
     for (auto &txin : tx1.vin) {
         txin.scriptSig = CScript();
     }
 
     for (auto &txin : tx2.vin) {
         txin.scriptSig = CScript();
     }
 
     return CTransaction(tx1) == CTransaction(tx2);
 }
 
 // Rebroadcast transactions from the wallet. We do this on a random timer
 // to slightly obfuscate which transactions come from our wallet.
 //
 // Ideally, we'd only resend transactions that we think should have been
 // mined in the most recent block. Any transaction that wasn't in the top
 // blockweight of transactions in the mempool shouldn't have been mined,
 // and so is probably just sitting in the mempool waiting to be confirmed.
 // Rebroadcasting does nothing to speed up confirmation and only damages
 // privacy.
 void CWallet::ResendWalletTransactions() {
     // During reindex, importing and IBD, old wallet transactions become
     // unconfirmed. Don't resend them as that would spam other nodes.
     if (!chain().isReadyToBroadcast()) {
         return;
     }
 
     // Do this infrequently and randomly to avoid giving away that these are our
     // transactions.
     if (GetTime() < nNextResend || !fBroadcastTransactions) {
         return;
     }
 
     bool fFirst = (nNextResend == 0);
     nNextResend = GetTime() + GetRand(30 * 60);
     if (fFirst) {
         return;
     }
 
     // Only do it if there's been a new block since last time
     if (m_best_block_time < nLastResend) {
         return;
     }
 
     nLastResend = GetTime();
 
     int submitted_tx_count = 0;
 
     { // locked_chain and cs_wallet scope
         auto locked_chain = chain().lock();
         LOCK(cs_wallet);
 
         // Relay transactions
         for (std::pair<const TxId, CWalletTx> &item : mapWallet) {
             CWalletTx &wtx = item.second;
             // Attempt to rebroadcast all txes more than 5 minutes older than
             // the last block. SubmitMemoryPoolAndRelay() will not rebroadcast
             // any confirmed or conflicting txs.
             if (wtx.nTimeReceived > m_best_block_time - 5 * 60) {
                 continue;
             }
             std::string unused_err_string;
             if (wtx.SubmitMemoryPoolAndRelay(unused_err_string, true,
                                              *locked_chain)) {
                 ++submitted_tx_count;
             }
         }
     } // locked_chain and cs_wallet
 
     if (submitted_tx_count > 0) {
         WalletLogPrintf("%s: resubmit %u unconfirmed transactions\n", __func__,
                         submitted_tx_count);
     }
 }
 
 /** @} */ // end of mapWallet
 
 void MaybeResendWalletTxs() {
     for (const std::shared_ptr<CWallet> &pwallet : GetWallets()) {
         pwallet->ResendWalletTransactions();
     }
 }
 
 /**
  * @defgroup Actions
  *
  * @{
  */
 CWallet::Balance CWallet::GetBalance(const int min_depth,
                                      bool avoid_reuse) const {
     Balance ret;
     isminefilter reuse_filter = avoid_reuse ? ISMINE_NO : ISMINE_USED;
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
     for (const auto &entry : mapWallet) {
         const CWalletTx &wtx = entry.second;
         const bool is_trusted{wtx.IsTrusted(*locked_chain)};
         const int tx_depth{wtx.GetDepthInMainChain(*locked_chain)};
         const Amount tx_credit_mine{
             wtx.GetAvailableCredit(*locked_chain, /* fUseCache */ true,
                                    ISMINE_SPENDABLE | reuse_filter)};
         const Amount tx_credit_watchonly{
             wtx.GetAvailableCredit(*locked_chain, /* fUseCache */ true,
                                    ISMINE_WATCH_ONLY | reuse_filter)};
         if (is_trusted && tx_depth >= min_depth) {
             ret.m_mine_trusted += tx_credit_mine;
             ret.m_watchonly_trusted += tx_credit_watchonly;
         }
         if (!is_trusted && tx_depth == 0 && wtx.InMempool()) {
             ret.m_mine_untrusted_pending += tx_credit_mine;
             ret.m_watchonly_untrusted_pending += tx_credit_watchonly;
         }
         ret.m_mine_immature += wtx.GetImmatureCredit(*locked_chain);
         ret.m_watchonly_immature +=
             wtx.GetImmatureWatchOnlyCredit(*locked_chain);
     }
     return ret;
 }
 
 Amount CWallet::GetAvailableBalance(const CCoinControl *coinControl) const {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     Amount balance = Amount::zero();
     std::vector<COutput> vCoins;
     AvailableCoins(*locked_chain, vCoins, true, coinControl);
     for (const COutput &out : vCoins) {
         if (out.fSpendable) {
             balance += out.tx->tx->vout[out.i].nValue;
         }
     }
     return balance;
 }
 
 void CWallet::AvailableCoins(interfaces::Chain::Lock &locked_chain,
                              std::vector<COutput> &vCoins, bool fOnlySafe,
                              const CCoinControl *coinControl,
                              const Amount nMinimumAmount,
                              const Amount nMaximumAmount,
                              const Amount nMinimumSumAmount,
                              const uint64_t nMaximumCount) const {
     AssertLockHeld(cs_wallet);
 
     vCoins.clear();
     Amount nTotal = Amount::zero();
     // Either the WALLET_FLAG_AVOID_REUSE flag is not set (in which case we
     // always allow), or we default to avoiding, and only in the case where a
     // coin control object is provided, and has the avoid address reuse flag set
     // to false, do we allow already used addresses
     bool allow_used_addresses =
         !IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE) ||
         (coinControl && !coinControl->m_avoid_address_reuse);
     const int min_depth = {coinControl ? coinControl->m_min_depth
                                        : DEFAULT_MIN_DEPTH};
     const int max_depth = {coinControl ? coinControl->m_max_depth
                                        : DEFAULT_MAX_DEPTH};
 
     const Consensus::Params params = Params().GetConsensus();
 
     for (const auto &entry : mapWallet) {
         const TxId &wtxid = entry.first;
         const CWalletTx &wtx = entry.second;
 
         TxValidationState state;
         if (!locked_chain.contextualCheckTransactionForCurrentBlock(
                 params, *wtx.tx, state)) {
             continue;
         }
 
         if (wtx.IsImmatureCoinBase(locked_chain)) {
             continue;
         }
 
         int nDepth = wtx.GetDepthInMainChain(locked_chain);
         if (nDepth < 0) {
             continue;
         }
 
         // We should not consider coins which aren't at least in our mempool.
         // It's possible for these to be conflicted via ancestors which we may
         // never be able to detect.
         if (nDepth == 0 && !wtx.InMempool()) {
             continue;
         }
 
         bool safeTx = wtx.IsTrusted(locked_chain);
 
         // Bitcoin-ABC: Removed check that prevents consideration of coins from
         // transactions that are replacing other transactions. This check based
         // on wtx.mapValue.count("replaces_txid") which was not being set
         // anywhere.
 
         // Similarly, we should not consider coins from transactions that have
         // been replaced. In the example above, we would want to prevent
         // creation of a transaction A' spending an output of A, because if
         // transaction B were initially confirmed, conflicting with A and A', we
         // wouldn't want to the user to create a transaction D intending to
         // replace A', but potentially resulting in a scenario where A, A', and
         // D could all be accepted (instead of just B and D, or just A and A'
         // like the user would want).
 
         // Bitcoin-ABC: retained this check as 'replaced_by_txid' is still set
         // in the wallet code.
         if (nDepth == 0 && wtx.mapValue.count("replaced_by_txid")) {
             safeTx = false;
         }
 
         if (fOnlySafe && !safeTx) {
             continue;
         }
 
         if (nDepth < min_depth || nDepth > max_depth) {
             continue;
         }
 
         for (uint32_t i = 0; i < wtx.tx->vout.size(); i++) {
             if (wtx.tx->vout[i].nValue < nMinimumAmount ||
                 wtx.tx->vout[i].nValue > nMaximumAmount) {
                 continue;
             }
 
             const COutPoint outpoint(wtxid, i);
 
             if (coinControl && coinControl->HasSelected() &&
                 !coinControl->fAllowOtherInputs &&
                 !coinControl->IsSelected(outpoint)) {
                 continue;
             }
 
             if (IsLockedCoin(outpoint)) {
                 continue;
             }
 
             if (IsSpent(locked_chain, outpoint)) {
                 continue;
             }
 
             isminetype mine = IsMine(wtx.tx->vout[i]);
 
             if (mine == ISMINE_NO) {
                 continue;
             }
 
             if (!allow_used_addresses && IsUsedDestination(wtxid, i)) {
                 continue;
             }
 
             const SigningProvider *provider = GetSigningProvider();
 
             bool solvable =
                 provider ? IsSolvable(*provider, wtx.tx->vout[i].scriptPubKey)
                          : false;
             bool spendable =
                 ((mine & ISMINE_SPENDABLE) != ISMINE_NO) ||
                 (((mine & ISMINE_WATCH_ONLY) != ISMINE_NO) &&
                  (coinControl && coinControl->fAllowWatchOnly && solvable));
 
             vCoins.push_back(
                 COutput(&wtx, i, nDepth, spendable, solvable, safeTx,
                         (coinControl && coinControl->fAllowWatchOnly)));
 
             // Checks the sum amount of all UTXO's.
             if (nMinimumSumAmount != MAX_MONEY) {
                 nTotal += wtx.tx->vout[i].nValue;
 
                 if (nTotal >= nMinimumSumAmount) {
                     return;
                 }
             }
 
             // Checks the maximum number of UTXO's.
             if (nMaximumCount > 0 && vCoins.size() >= nMaximumCount) {
                 return;
             }
         }
     }
 }
 
 std::map<CTxDestination, std::vector<COutput>>
 CWallet::ListCoins(interfaces::Chain::Lock &locked_chain) const {
     AssertLockHeld(cs_wallet);
 
     std::map<CTxDestination, std::vector<COutput>> result;
     std::vector<COutput> availableCoins;
 
     AvailableCoins(locked_chain, availableCoins);
 
     for (const auto &coin : availableCoins) {
         CTxDestination address;
         if (coin.fSpendable &&
             ExtractDestination(
                 FindNonChangeParentOutput(*coin.tx->tx, coin.i).scriptPubKey,
                 address)) {
             result[address].emplace_back(std::move(coin));
         }
     }
 
     std::vector<COutPoint> lockedCoins;
     ListLockedCoins(lockedCoins);
     for (const auto &output : lockedCoins) {
         auto it = mapWallet.find(output.GetTxId());
         if (it != mapWallet.end()) {
             int depth = it->second.GetDepthInMainChain(locked_chain);
             if (depth >= 0 && output.GetN() < it->second.tx->vout.size() &&
                 IsMine(it->second.tx->vout[output.GetN()]) ==
                     ISMINE_SPENDABLE) {
                 CTxDestination address;
                 if (ExtractDestination(
                         FindNonChangeParentOutput(*it->second.tx, output.GetN())
                             .scriptPubKey,
                         address)) {
                     result[address].emplace_back(
                         &it->second, output.GetN(), depth, true /* spendable */,
                         true /* solvable */, false /* safe */);
                 }
             }
         }
     }
 
     return result;
 }
 
 const CTxOut &CWallet::FindNonChangeParentOutput(const CTransaction &tx,
                                                  int output) const {
     const CTransaction *ptx = &tx;
     int n = output;
     while (IsChange(ptx->vout[n]) && ptx->vin.size() > 0) {
         const COutPoint &prevout = ptx->vin[0].prevout;
         auto it = mapWallet.find(prevout.GetTxId());
         if (it == mapWallet.end() ||
             it->second.tx->vout.size() <= prevout.GetN() ||
             !IsMine(it->second.tx->vout[prevout.GetN()])) {
             break;
         }
         ptx = it->second.tx.get();
         n = prevout.GetN();
     }
     return ptx->vout[n];
 }
 
 bool CWallet::SelectCoinsMinConf(
     const Amount nTargetValue, const CoinEligibilityFilter &eligibility_filter,
     std::vector<OutputGroup> groups, std::set<CInputCoin> &setCoinsRet,
     Amount &nValueRet, const CoinSelectionParams &coin_selection_params,
     bool &bnb_used) const {
     setCoinsRet.clear();
     nValueRet = Amount::zero();
 
     std::vector<OutputGroup> utxo_pool;
     if (coin_selection_params.use_bnb) {
         // Get long term estimate
         CCoinControl temp;
         temp.m_confirm_target = 1008;
         CFeeRate long_term_feerate = GetMinimumFeeRate(*this, temp);
 
         // Calculate cost of change
         Amount cost_of_change = chain().relayDustFee().GetFee(
                                     coin_selection_params.change_spend_size) +
                                 coin_selection_params.effective_fee.GetFee(
                                     coin_selection_params.change_output_size);
 
         // Filter by the min conf specs and add to utxo_pool and calculate
         // effective value
         for (OutputGroup &group : groups) {
             if (!group.EligibleForSpending(eligibility_filter)) {
                 continue;
             }
 
             group.fee = Amount::zero();
             group.long_term_fee = Amount::zero();
             group.effective_value = Amount::zero();
             for (auto it = group.m_outputs.begin();
                  it != group.m_outputs.end();) {
                 const CInputCoin &coin = *it;
                 Amount effective_value =
                     coin.txout.nValue -
                     (coin.m_input_bytes < 0
                          ? Amount::zero()
                          : coin_selection_params.effective_fee.GetFee(
                                coin.m_input_bytes));
                 // Only include outputs that are positive effective value (i.e.
                 // not dust)
                 if (effective_value > Amount::zero()) {
                     group.fee +=
                         coin.m_input_bytes < 0
                             ? Amount::zero()
                             : coin_selection_params.effective_fee.GetFee(
                                   coin.m_input_bytes);
                     group.long_term_fee +=
                         coin.m_input_bytes < 0
                             ? Amount::zero()
                             : long_term_feerate.GetFee(coin.m_input_bytes);
                     group.effective_value += effective_value;
                     ++it;
                 } else {
                     it = group.Discard(coin);
                 }
             }
             if (group.effective_value > Amount::zero()) {
                 utxo_pool.push_back(group);
             }
         }
         // Calculate the fees for things that aren't inputs
         Amount not_input_fees = coin_selection_params.effective_fee.GetFee(
             coin_selection_params.tx_noinputs_size);
         bnb_used = true;
         return SelectCoinsBnB(utxo_pool, nTargetValue, cost_of_change,
                               setCoinsRet, nValueRet, not_input_fees);
     } else {
         // Filter by the min conf specs and add to utxo_pool
         for (const OutputGroup &group : groups) {
             if (!group.EligibleForSpending(eligibility_filter)) {
                 continue;
             }
             utxo_pool.push_back(group);
         }
         bnb_used = false;
         return KnapsackSolver(nTargetValue, utxo_pool, setCoinsRet, nValueRet);
     }
 }
 
 bool CWallet::SelectCoins(const std::vector<COutput> &vAvailableCoins,
                           const Amount nTargetValue,
                           std::set<CInputCoin> &setCoinsRet, Amount &nValueRet,
                           const CCoinControl &coin_control,
                           CoinSelectionParams &coin_selection_params,
                           bool &bnb_used) const {
     std::vector<COutput> vCoins(vAvailableCoins);
 
     // coin control -> return all selected outputs (we want all selected to go
     // into the transaction for sure)
     if (coin_control.HasSelected() && !coin_control.fAllowOtherInputs) {
         // We didn't use BnB here, so set it to false.
         bnb_used = false;
 
         for (const COutput &out : vCoins) {
             if (!out.fSpendable) {
                 continue;
             }
 
             nValueRet += out.tx->tx->vout[out.i].nValue;
             setCoinsRet.insert(out.GetInputCoin());
         }
 
         return (nValueRet >= nTargetValue);
     }
 
     // Calculate value from preset inputs and store them.
     std::set<CInputCoin> setPresetCoins;
     Amount nValueFromPresetInputs = Amount::zero();
 
     std::vector<COutPoint> vPresetInputs;
     coin_control.ListSelected(vPresetInputs);
 
     for (const COutPoint &outpoint : vPresetInputs) {
         // For now, don't use BnB if preset inputs are selected. TODO: Enable
         // this later
         bnb_used = false;
         coin_selection_params.use_bnb = false;
 
         std::map<TxId, CWalletTx>::const_iterator it =
             mapWallet.find(outpoint.GetTxId());
         if (it == mapWallet.end()) {
             // TODO: Allow non-wallet inputs
             return false;
         }
 
         const CWalletTx &wtx = it->second;
         // Clearly invalid input, fail.
         if (wtx.tx->vout.size() <= outpoint.GetN()) {
             return false;
         }
 
         // Just to calculate the marginal byte size
         nValueFromPresetInputs += wtx.tx->vout[outpoint.GetN()].nValue;
         setPresetCoins.insert(CInputCoin(wtx.tx, outpoint.GetN()));
     }
 
     // Remove preset inputs from vCoins
     for (std::vector<COutput>::iterator it = vCoins.begin();
          it != vCoins.end() && coin_control.HasSelected();) {
         if (setPresetCoins.count(it->GetInputCoin())) {
             it = vCoins.erase(it);
         } else {
             ++it;
         }
     }
 
     // form groups from remaining coins; note that preset coins will not
     // automatically have their associated (same address) coins included
     if (coin_control.m_avoid_partial_spends &&
         vCoins.size() > OUTPUT_GROUP_MAX_ENTRIES) {
         // Cases where we have 11+ outputs all pointing to the same destination
         // may result in privacy leaks as they will potentially be
         // deterministically sorted. We solve that by explicitly shuffling the
         // outputs before processing
         Shuffle(vCoins.begin(), vCoins.end(), FastRandomContext());
     }
     std::vector<OutputGroup> groups =
         GroupOutputs(vCoins, !coin_control.m_avoid_partial_spends);
 
     size_t max_ancestors{0};
     size_t max_descendants{0};
     chain().getPackageLimits(max_ancestors, max_descendants);
     bool fRejectLongChains = gArgs.GetBoolArg(
         "-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
 
     bool res =
         nTargetValue <= nValueFromPresetInputs ||
         SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                            CoinEligibilityFilter(1, 6, 0), groups, setCoinsRet,
                            nValueRet, coin_selection_params, bnb_used) ||
         SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                            CoinEligibilityFilter(1, 1, 0), groups, setCoinsRet,
                            nValueRet, coin_selection_params, bnb_used) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                             CoinEligibilityFilter(0, 1, 2), groups, setCoinsRet,
                             nValueRet, coin_selection_params, bnb_used)) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(
              nTargetValue - nValueFromPresetInputs,
              CoinEligibilityFilter(0, 1, std::min<size_t>(4, max_ancestors / 3),
                                    std::min<size_t>(4, max_descendants / 3)),
              groups, setCoinsRet, nValueRet, coin_selection_params,
              bnb_used)) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                             CoinEligibilityFilter(0, 1, max_ancestors / 2,
                                                   max_descendants / 2),
                             groups, setCoinsRet, nValueRet,
                             coin_selection_params, bnb_used)) ||
         (m_spend_zero_conf_change &&
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs,
                             CoinEligibilityFilter(0, 1, max_ancestors - 1,
                                                   max_descendants - 1),
                             groups, setCoinsRet, nValueRet,
                             coin_selection_params, bnb_used)) ||
         (m_spend_zero_conf_change && !fRejectLongChains &&
          SelectCoinsMinConf(
              nTargetValue - nValueFromPresetInputs,
              CoinEligibilityFilter(0, 1, std::numeric_limits<uint64_t>::max()),
              groups, setCoinsRet, nValueRet, coin_selection_params, bnb_used));
 
     // Because SelectCoinsMinConf clears the setCoinsRet, we now add the
     // possible inputs to the coinset.
     util::insert(setCoinsRet, setPresetCoins);
 
     // Add preset inputs to the total value selected.
     nValueRet += nValueFromPresetInputs;
 
     return res;
 }
 
 bool CWallet::SignTransaction(CMutableTransaction &tx) {
     AssertLockHeld(cs_wallet);
     // sign the new tx
     int nIn = 0;
     for (CTxIn &input : tx.vin) {
         auto mi = mapWallet.find(input.prevout.GetTxId());
         if (mi == mapWallet.end() ||
             input.prevout.GetN() >= mi->second.tx->vout.size()) {
             return false;
         }
         const CScript &scriptPubKey =
             mi->second.tx->vout[input.prevout.GetN()].scriptPubKey;
         const Amount amount = mi->second.tx->vout[input.prevout.GetN()].nValue;
         SignatureData sigdata;
         SigHashType sigHashType = SigHashType().withForkId();
 
         const SigningProvider *provider = GetSigningProvider();
         if (!provider) {
             return false;
         }
 
         if (!ProduceSignature(*provider,
                               MutableTransactionSignatureCreator(
                                   &tx, nIn, amount, sigHashType),
                               scriptPubKey, sigdata)) {
             return false;
         }
         UpdateInput(input, sigdata);
         nIn++;
     }
     return true;
 }
 
 bool CWallet::FundTransaction(CMutableTransaction &tx, Amount &nFeeRet,
                               int &nChangePosInOut, std::string &strFailReason,
                               bool lockUnspents,
                               const std::set<int> &setSubtractFeeFromOutputs,
                               CCoinControl coinControl) {
     std::vector<CRecipient> vecSend;
 
     // Turn the txout set into a CRecipient vector.
     for (size_t idx = 0; idx < tx.vout.size(); idx++) {
         const CTxOut &txOut = tx.vout[idx];
         CRecipient recipient = {txOut.scriptPubKey, txOut.nValue,
                                 setSubtractFeeFromOutputs.count(idx) == 1};
         vecSend.push_back(recipient);
     }
 
     coinControl.fAllowOtherInputs = true;
 
     for (const CTxIn &txin : tx.vin) {
         coinControl.Select(txin.prevout);
     }
 
     // Acquire the locks to prevent races to the new locked unspents between the
     // CreateTransaction call and LockCoin calls (when lockUnspents is true).
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     CTransactionRef tx_new;
     if (!CreateTransaction(*locked_chain, vecSend, tx_new, nFeeRet,
                            nChangePosInOut, strFailReason, coinControl,
                            false)) {
         return false;
     }
 
     if (nChangePosInOut != -1) {
         tx.vout.insert(tx.vout.begin() + nChangePosInOut,
                        tx_new->vout[nChangePosInOut]);
     }
 
     // Copy output sizes from new transaction; they may have had the fee
     // subtracted from them.
     for (size_t idx = 0; idx < tx.vout.size(); idx++) {
         tx.vout[idx].nValue = tx_new->vout[idx].nValue;
     }
 
     // Add new txins (keeping original txin scriptSig/order)
     for (const CTxIn &txin : tx_new->vin) {
         if (!coinControl.IsSelected(txin.prevout)) {
             tx.vin.push_back(txin);
 
             if (lockUnspents) {
                 LockCoin(txin.prevout);
             }
         }
     }
 
     return true;
 }
 
 static bool IsCurrentForAntiFeeSniping(interfaces::Chain &chain,
                                        interfaces::Chain::Lock &locked_chain) {
     if (chain.isInitialBlockDownload()) {
         return false;
     }
 
     // in seconds
     constexpr int64_t MAX_ANTI_FEE_SNIPING_TIP_AGE = 8 * 60 * 60;
     if (locked_chain.getBlockTime(*locked_chain.getHeight()) <
         (GetTime() - MAX_ANTI_FEE_SNIPING_TIP_AGE)) {
         return false;
     }
     return true;
 }
 
 /**
  * Return a height-based locktime for new transactions (uses the height of the
  * current chain tip unless we are not synced with the current chain
  */
 static uint32_t
 GetLocktimeForNewTransaction(interfaces::Chain &chain,
                              interfaces::Chain::Lock &locked_chain) {
     uint32_t const height = locked_chain.getHeight().value_or(-1);
     uint32_t locktime;
     // Discourage fee sniping.
     //
     // For a large miner the value of the transactions in the best block and
     // the mempool can exceed the cost of deliberately attempting to mine two
     // blocks to orphan the current best block. By setting nLockTime such that
     // only the next block can include the transaction, we discourage this
     // practice as the height restricted and limited blocksize gives miners
     // considering fee sniping fewer options for pulling off this attack.
     //
     // A simple way to think about this is from the wallet's point of view we
     // always want the blockchain to move forward. By setting nLockTime this
     // way we're basically making the statement that we only want this
     // transaction to appear in the next block; we don't want to potentially
     // encourage reorgs by allowing transactions to appear at lower heights
     // than the next block in forks of the best chain.
     //
     // Of course, the subsidy is high enough, and transaction volume low
     // enough, that fee sniping isn't a problem yet, but by implementing a fix
     // now we ensure code won't be written that makes assumptions about
     // nLockTime that preclude a fix later.
     if (IsCurrentForAntiFeeSniping(chain, locked_chain)) {
         locktime = height;
 
         // Secondly occasionally randomly pick a nLockTime even further back, so
         // that transactions that are delayed after signing for whatever reason,
         // e.g. high-latency mix networks and some CoinJoin implementations,
         // have better privacy.
         if (GetRandInt(10) == 0) {
             locktime = std::max(0, int(locktime) - GetRandInt(100));
         }
     } else {
         // If our chain is lagging behind, we can't discourage fee sniping nor
         // help the privacy of high-latency transactions. To avoid leaking a
         // potentially unique "nLockTime fingerprint", set nLockTime to a
         // constant.
         locktime = 0;
     }
     assert(locktime <= height);
     assert(locktime < LOCKTIME_THRESHOLD);
     return locktime;
 }
 
 OutputType
 CWallet::TransactionChangeType(OutputType change_type,
                                const std::vector<CRecipient> &vecSend) {
     // If -changetype is specified, always use that change type.
     if (change_type != OutputType::CHANGE_AUTO) {
         return change_type;
     }
 
     // if m_default_address_type is legacy, use legacy address as change.
     if (m_default_address_type == OutputType::LEGACY) {
         return OutputType::LEGACY;
     }
 
     // else use m_default_address_type for change
     return m_default_address_type;
 }
 
 bool CWallet::CreateTransaction(interfaces::Chain::Lock &locked_chainIn,
                                 const std::vector<CRecipient> &vecSend,
                                 CTransactionRef &tx, Amount &nFeeRet,
                                 int &nChangePosInOut,
                                 std::string &strFailReason,
                                 const CCoinControl &coinControl, bool sign) {
     Amount nValue = Amount::zero();
     ReserveDestination reservedest(this);
     int nChangePosRequest = nChangePosInOut;
     unsigned int nSubtractFeeFromAmount = 0;
     for (const auto &recipient : vecSend) {
         if (nValue < Amount::zero() || recipient.nAmount < Amount::zero()) {
             strFailReason =
                 _("Transaction amounts must not be negative").translated;
             return false;
         }
 
         nValue += recipient.nAmount;
 
         if (recipient.fSubtractFeeFromAmount) {
             nSubtractFeeFromAmount++;
         }
     }
 
     if (vecSend.empty()) {
         strFailReason =
             _("Transaction must have at least one recipient").translated;
         return false;
     }
 
     CMutableTransaction txNew;
 
     txNew.nLockTime = GetLocktimeForNewTransaction(chain(), locked_chainIn);
 
     {
         std::set<CInputCoin> setCoins;
         auto locked_chain = chain().lock();
         LOCK(cs_wallet);
 
         std::vector<COutput> vAvailableCoins;
         AvailableCoins(*locked_chain, vAvailableCoins, true, &coinControl);
         // Parameters for coin selection, init with dummy
         CoinSelectionParams coin_selection_params;
 
         // Create change script that will be used if we need change
         // TODO: pass in scriptChange instead of reservedest so
         // change transaction isn't always pay-to-bitcoin-address
         CScript scriptChange;
 
         // coin control: send change to custom address
         if (!boost::get<CNoDestination>(&coinControl.destChange)) {
             scriptChange = GetScriptForDestination(coinControl.destChange);
 
             // no coin control: send change to newly generated address
         } else {
             // Note: We use a new key here to keep it from being obvious
             // which side is the change.
             //  The drawback is that by not reusing a previous key, the
             //  change may be lost if a backup is restored, if the backup
             //  doesn't have the new private key for the change. If we
             //  reused the old key, it would be possible to add code to look
             //  for and rediscover unknown transactions that were written
             //  with keys of ours to recover post-backup change.
 
             // Reserve a new key pair from key pool
             if (!CanGetAddresses(true)) {
                 strFailReason =
                     _("Can't generate a change-address key. No keys in the "
                       "internal keypool and can't generate any keys.")
                         .translated;
                 return false;
             }
             CTxDestination dest;
             const OutputType change_type = TransactionChangeType(
                 coinControl.m_change_type ? *coinControl.m_change_type
                                           : m_default_change_type,
                 vecSend);
             bool ret =
                 reservedest.GetReservedDestination(change_type, dest, true);
             if (!ret) {
                 strFailReason =
                     _("Keypool ran out, please call keypoolrefill first")
                         .translated;
                 return false;
             }
 
             scriptChange = GetScriptForDestination(dest);
         }
         CTxOut change_prototype_txout(Amount::zero(), scriptChange);
         coin_selection_params.change_output_size =
             GetSerializeSize(change_prototype_txout);
 
         // Get the fee rate to use effective values in coin selection
         CFeeRate nFeeRateNeeded = GetMinimumFeeRate(*this, coinControl);
 
         nFeeRet = Amount::zero();
         bool pick_new_inputs = true;
         Amount nValueIn = Amount::zero();
 
         // BnB selector is the only selector used when this is true.
         // That should only happen on the first pass through the loop.
         // If we are doing subtract fee from recipient, then don't use BnB
         coin_selection_params.use_bnb = nSubtractFeeFromAmount == 0;
         // Start with no fee and loop until there is enough fee
         while (true) {
             nChangePosInOut = nChangePosRequest;
             txNew.vin.clear();
             txNew.vout.clear();
             bool fFirst = true;
 
             Amount nValueToSelect = nValue;
             if (nSubtractFeeFromAmount == 0) {
                 nValueToSelect += nFeeRet;
             }
 
             // Static size overhead + outputs vsize. 4 nVersion, 4 nLocktime, 1
             // input count, 1 output count
             coin_selection_params.tx_noinputs_size = 10;
             // vouts to the payees
             for (const auto &recipient : vecSend) {
                 CTxOut txout(recipient.nAmount, recipient.scriptPubKey);
 
                 if (recipient.fSubtractFeeFromAmount) {
                     assert(nSubtractFeeFromAmount != 0);
                     // Subtract fee equally from each selected recipient.
                     txout.nValue -= nFeeRet / int(nSubtractFeeFromAmount);
 
                     // First receiver pays the remainder not divisible by output
                     // count.
                     if (fFirst) {
                         fFirst = false;
                         txout.nValue -= nFeeRet % int(nSubtractFeeFromAmount);
                     }
                 }
 
                 // Include the fee cost for outputs. Note this is only used for
                 // BnB right now
                 coin_selection_params.tx_noinputs_size +=
                     ::GetSerializeSize(txout, PROTOCOL_VERSION);
 
                 if (IsDust(txout, chain().relayDustFee())) {
                     if (recipient.fSubtractFeeFromAmount &&
                         nFeeRet > Amount::zero()) {
                         if (txout.nValue < Amount::zero()) {
                             strFailReason = _("The transaction amount is too "
                                               "small to pay the fee")
                                                 .translated;
                         } else {
                             strFailReason =
                                 _("The transaction amount is too small to "
                                   "send after the fee has been deducted")
                                     .translated;
                         }
                     } else {
                         strFailReason =
                             _("Transaction amount too small").translated;
                     }
 
                     return false;
                 }
 
                 txNew.vout.push_back(txout);
             }
 
             // Choose coins to use
             bool bnb_used;
             if (pick_new_inputs) {
                 nValueIn = Amount::zero();
                 setCoins.clear();
                 coin_selection_params.change_spend_size =
                     CalculateMaximumSignedInputSize(change_prototype_txout,
                                                     this);
                 coin_selection_params.effective_fee = nFeeRateNeeded;
                 if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins,
                                  nValueIn, coinControl, coin_selection_params,
                                  bnb_used)) {
                     // If BnB was used, it was the first pass. No longer the
                     // first pass and continue loop with knapsack.
                     if (bnb_used) {
                         coin_selection_params.use_bnb = false;
                         continue;
                     } else {
                         strFailReason = _("Insufficient funds").translated;
                         return false;
                     }
                 }
             } else {
                 bnb_used = false;
             }
 
             const Amount nChange = nValueIn - nValueToSelect;
             if (nChange > Amount::zero()) {
                 // Fill a vout to ourself.
                 CTxOut newTxOut(nChange, scriptChange);
 
                 // Never create dust outputs; if we would, just add the dust to
                 // the fee.
                 // The nChange when BnB is used is always going to go to fees.
                 if (IsDust(newTxOut, chain().relayDustFee()) || bnb_used) {
                     nChangePosInOut = -1;
                     nFeeRet += nChange;
                 } else {
                     if (nChangePosInOut == -1) {
                         // Insert change txn at random position:
                         nChangePosInOut = GetRandInt(txNew.vout.size() + 1);
                     } else if ((unsigned int)nChangePosInOut >
                                txNew.vout.size()) {
                         strFailReason =
                             _("Change index out of range").translated;
                         return false;
                     }
 
                     std::vector<CTxOut>::iterator position =
                         txNew.vout.begin() + nChangePosInOut;
                     txNew.vout.insert(position, newTxOut);
                 }
             } else {
                 nChangePosInOut = -1;
             }
 
             // Dummy fill vin for maximum size estimation
             //
             for (const auto &coin : setCoins) {
                 txNew.vin.push_back(CTxIn(coin.outpoint, CScript()));
             }
 
             CTransaction txNewConst(txNew);
             int nBytes = CalculateMaximumSignedTxSize(
                 txNewConst, this, coinControl.fAllowWatchOnly);
             if (nBytes < 0) {
                 strFailReason = _("Signing transaction failed").translated;
                 return false;
             }
 
             Amount nFeeNeeded = GetMinimumFee(*this, nBytes, coinControl);
 
             if (nFeeRet >= nFeeNeeded) {
                 // Reduce fee to only the needed amount if possible. This
                 // prevents potential overpayment in fees if the coins selected
                 // to meet nFeeNeeded result in a transaction that requires less
                 // fee than the prior iteration.
 
                 // If we have no change and a big enough excess fee, then try to
                 // construct transaction again only without picking new inputs.
                 // We now know we only need the smaller fee (because of reduced
                 // tx size) and so we should add a change output. Only try this
                 // once.
                 if (nChangePosInOut == -1 && nSubtractFeeFromAmount == 0 &&
                     pick_new_inputs) {
                     // Add 2 as a buffer in case increasing # of outputs changes
                     // compact size
                     unsigned int tx_size_with_change =
                         nBytes + coin_selection_params.change_output_size + 2;
                     Amount fee_needed_with_change =
                         GetMinimumFee(*this, tx_size_with_change, coinControl);
                     Amount minimum_value_for_change = GetDustThreshold(
                         change_prototype_txout, chain().relayDustFee());
                     if (nFeeRet >=
                         fee_needed_with_change + minimum_value_for_change) {
                         pick_new_inputs = false;
                         nFeeRet = fee_needed_with_change;
                         continue;
                     }
                 }
 
                 // If we have change output already, just increase it
                 if (nFeeRet > nFeeNeeded && nChangePosInOut != -1 &&
                     nSubtractFeeFromAmount == 0) {
                     Amount extraFeePaid = nFeeRet - nFeeNeeded;
                     std::vector<CTxOut>::iterator change_position =
                         txNew.vout.begin() + nChangePosInOut;
                     change_position->nValue += extraFeePaid;
                     nFeeRet -= extraFeePaid;
                 }
 
                 // Done, enough fee included.
                 break;
             } else if (!pick_new_inputs) {
                 // This shouldn't happen, we should have had enough excess fee
                 // to pay for the new output and still meet nFeeNeeded.
                 // Or we should have just subtracted fee from recipients and
                 // nFeeNeeded should not have changed.
                 strFailReason =
                     _("Transaction fee and change calculation failed")
                         .translated;
                 return false;
             }
 
             // Try to reduce change to include necessary fee.
             if (nChangePosInOut != -1 && nSubtractFeeFromAmount == 0) {
                 Amount additionalFeeNeeded = nFeeNeeded - nFeeRet;
                 std::vector<CTxOut>::iterator change_position =
                     txNew.vout.begin() + nChangePosInOut;
                 // Only reduce change if remaining amount is still a large
                 // enough output.
                 if (change_position->nValue >=
                     MIN_FINAL_CHANGE + additionalFeeNeeded) {
                     change_position->nValue -= additionalFeeNeeded;
                     nFeeRet += additionalFeeNeeded;
                     // Done, able to increase fee from change.
                     break;
                 }
             }
 
             // If subtracting fee from recipients, we now know what fee we
             // need to subtract, we have no reason to reselect inputs.
             if (nSubtractFeeFromAmount > 0) {
                 pick_new_inputs = false;
             }
 
             // Include more fee and try again.
             nFeeRet = nFeeNeeded;
             coin_selection_params.use_bnb = false;
             continue;
         }
 
         // Shuffle selected coins and fill in final vin
         txNew.vin.clear();
         std::vector<CInputCoin> selected_coins(setCoins.begin(),
                                                setCoins.end());
         Shuffle(selected_coins.begin(), selected_coins.end(),
                 FastRandomContext());
 
         // Note how the sequence number is set to non-maxint so that
         // the nLockTime set above actually works.
         for (const auto &coin : selected_coins) {
             txNew.vin.push_back(
                 CTxIn(coin.outpoint, CScript(),
                       std::numeric_limits<uint32_t>::max() - 1));
         }
 
         if (sign) {
             SigHashType sigHashType = SigHashType().withForkId();
 
             int nIn = 0;
             for (const auto &coin : selected_coins) {
                 const CScript &scriptPubKey = coin.txout.scriptPubKey;
                 SignatureData sigdata;
 
                 const SigningProvider *provider = GetSigningProvider();
                 if (!provider ||
                     !ProduceSignature(
                         *provider,
                         MutableTransactionSignatureCreator(
                             &txNew, nIn, coin.txout.nValue, sigHashType),
                         scriptPubKey, sigdata)) {
                     strFailReason = _("Signing transaction failed").translated;
                     return false;
                 }
 
                 UpdateInput(txNew.vin.at(nIn), sigdata);
                 nIn++;
             }
         }
 
         // Return the constructed transaction data.
         tx = MakeTransactionRef(std::move(txNew));
 
         // Limit size.
         if (tx->GetTotalSize() > MAX_STANDARD_TX_SIZE) {
             strFailReason = _("Transaction too large").translated;
             return false;
         }
     }
 
     if (nFeeRet > m_default_max_tx_fee) {
         strFailReason =
             TransactionErrorString(TransactionError::MAX_FEE_EXCEEDED);
         return false;
     }
 
     if (gArgs.GetBoolArg("-walletrejectlongchains",
                          DEFAULT_WALLET_REJECT_LONG_CHAINS)) {
         // Lastly, ensure this tx will pass the mempool's chain limits
         if (!chain().checkChainLimits(tx)) {
             strFailReason =
                 _("Transaction has too long of a mempool chain").translated;
             return false;
         }
     }
 
     // Before we return success, we assume any change key will be used to
     // prevent accidental re-use.
     reservedest.KeepDestination();
 
     return true;
 }
 
 void CWallet::CommitTransaction(
     CTransactionRef tx, mapValue_t mapValue,
     std::vector<std::pair<std::string, std::string>> orderForm) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     CWalletTx wtxNew(this, std::move(tx));
     wtxNew.mapValue = std::move(mapValue);
     wtxNew.vOrderForm = std::move(orderForm);
     wtxNew.fTimeReceivedIsTxTime = true;
     wtxNew.fFromMe = true;
 
     WalletLogPrintfToBeContinued("CommitTransaction:\n%s",
                                  wtxNew.tx->ToString());
 
     // Add tx to wallet, because if it has change it's also ours, otherwise just
     // for transaction history.
     AddToWallet(wtxNew);
 
     // Notify that old coins are spent.
     for (const CTxIn &txin : wtxNew.tx->vin) {
         CWalletTx &coin = mapWallet.at(txin.prevout.GetTxId());
         coin.BindWallet(this);
         NotifyTransactionChanged(this, coin.GetId(), CT_UPDATED);
     }
 
     // Get the inserted-CWalletTx from mapWallet so that the
     // fInMempool flag is cached properly
     CWalletTx &wtx = mapWallet.at(wtxNew.GetId());
 
     if (!fBroadcastTransactions) {
         // Don't submit tx to the mempool
         return;
     }
 
     std::string err_string;
     if (!wtx.SubmitMemoryPoolAndRelay(err_string, true, *locked_chain)) {
         WalletLogPrintf("CommitTransaction(): Transaction cannot be broadcast "
                         "immediately, %s\n",
                         err_string);
         // TODO: if we expect the failure to be long term or permanent, instead
         // delete wtx from the wallet and return failure.
     }
 }
 
 DBErrors CWallet::LoadWallet(bool &fFirstRunRet) {
     // Even if we don't use this lock in this function, we want to preserve
     // lock order in LoadToWallet if query of chain state is needed to know
     // tx status. If lock can't be taken (e.g wallet-tool), tx confirmation
     // status may be not reliable.
     auto locked_chain = LockChain();
     LOCK(cs_wallet);
 
     fFirstRunRet = false;
     DBErrors nLoadWalletRet = WalletBatch(*database, "cr+").LoadWallet(this);
     if (nLoadWalletRet == DBErrors::NEED_REWRITE) {
         if (database->Rewrite("\x04pool")) {
             if (auto spk_man = m_spk_man.get()) {
                 spk_man->RewriteDB();
             }
         }
     }
 
     {
         LOCK(cs_KeyStore);
         // This wallet is in its first run if all of these are empty
         fFirstRunRet = mapKeys.empty() && mapCryptedKeys.empty() &&
                        mapWatchKeys.empty() && setWatchOnly.empty() &&
                        mapScripts.empty() &&
                        !IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS) &&
                        !IsWalletFlagSet(WALLET_FLAG_BLANK_WALLET);
     }
 
     if (nLoadWalletRet != DBErrors::LOAD_OK) {
         return nLoadWalletRet;
     }
 
     return DBErrors::LOAD_OK;
 }
 
 DBErrors CWallet::ZapSelectTx(std::vector<TxId> &txIdsIn,
                               std::vector<TxId> &txIdsOut) {
     AssertLockHeld(cs_wallet);
     DBErrors nZapSelectTxRet =
         WalletBatch(*database, "cr+").ZapSelectTx(txIdsIn, txIdsOut);
     for (const TxId &txid : txIdsOut) {
         const auto &it = mapWallet.find(txid);
         wtxOrdered.erase(it->second.m_it_wtxOrdered);
         mapWallet.erase(it);
         NotifyTransactionChanged(this, txid, CT_DELETED);
     }
 
     if (nZapSelectTxRet == DBErrors::NEED_REWRITE) {
         if (database->Rewrite("\x04pool")) {
             if (auto spk_man = m_spk_man.get()) {
                 spk_man->RewriteDB();
             }
         }
     }
 
     if (nZapSelectTxRet != DBErrors::LOAD_OK) {
         return nZapSelectTxRet;
     }
 
     MarkDirty();
 
     return DBErrors::LOAD_OK;
 }
 
 DBErrors CWallet::ZapWalletTx(std::vector<CWalletTx> &vWtx) {
     DBErrors nZapWalletTxRet = WalletBatch(*database, "cr+").ZapWalletTx(vWtx);
     if (nZapWalletTxRet == DBErrors::NEED_REWRITE) {
         if (database->Rewrite("\x04pool")) {
             if (auto spk_man = m_spk_man.get()) {
                 spk_man->RewriteDB();
             }
         }
     }
 
     if (nZapWalletTxRet != DBErrors::LOAD_OK) {
         return nZapWalletTxRet;
     }
 
     return DBErrors::LOAD_OK;
 }
 
 bool CWallet::SetAddressBookWithDB(WalletBatch &batch,
                                    const CTxDestination &address,
                                    const std::string &strName,
                                    const std::string &strPurpose) {
     bool fUpdated = false;
     {
         LOCK(cs_wallet);
         std::map<CTxDestination, CAddressBookData>::iterator mi =
             mapAddressBook.find(address);
         fUpdated = mi != mapAddressBook.end();
         mapAddressBook[address].name = strName;
         // Update purpose only if requested.
         if (!strPurpose.empty()) {
             mapAddressBook[address].purpose = strPurpose;
         }
     }
 
     NotifyAddressBookChanged(this, address, strName,
                              IsMine(address) != ISMINE_NO, strPurpose,
                              (fUpdated ? CT_UPDATED : CT_NEW));
     if (!strPurpose.empty() && !batch.WritePurpose(address, strPurpose)) {
         return false;
     }
     return batch.WriteName(address, strName);
 }
 
 bool CWallet::SetAddressBook(const CTxDestination &address,
                              const std::string &strName,
                              const std::string &strPurpose) {
     WalletBatch batch(*database);
     return SetAddressBookWithDB(batch, address, strName, strPurpose);
 }
 
 bool CWallet::DelAddressBook(const CTxDestination &address) {
     {
         LOCK(cs_wallet);
 
         // Delete destdata tuples associated with address.
         for (const std::pair<const std::string, std::string> &item :
              mapAddressBook[address].destdata) {
             WalletBatch(*database).EraseDestData(address, item.first);
         }
 
         mapAddressBook.erase(address);
     }
 
     NotifyAddressBookChanged(this, address, "", IsMine(address) != ISMINE_NO,
                              "", CT_DELETED);
 
     WalletBatch(*database).ErasePurpose(address);
     return WalletBatch(*database).EraseName(address);
 }
 
 size_t CWallet::KeypoolCountExternalKeys() {
     AssertLockHeld(cs_wallet);
 
     unsigned int count = 0;
     if (auto spk_man = m_spk_man.get()) {
         AssertLockHeld(spk_man->cs_wallet);
         count += spk_man->KeypoolCountExternalKeys();
     }
 
     return count;
 }
 
 unsigned int CWallet::GetKeyPoolSize() const {
     AssertLockHeld(cs_wallet);
 
     unsigned int count = 0;
     if (auto spk_man = m_spk_man.get()) {
         count += spk_man->GetKeyPoolSize();
     }
     return count;
 }
 
 bool CWallet::TopUpKeyPool(unsigned int kpSize) {
     bool res = true;
     if (auto spk_man = m_spk_man.get()) {
         res &= spk_man->TopUp(kpSize);
     }
     return res;
 }
 
 bool CWallet::GetNewDestination(const OutputType type, const std::string label,
                                 CTxDestination &dest, std::string &error) {
     LOCK(cs_wallet);
     error.clear();
     bool result = false;
     auto spk_man = m_spk_man.get();
     if (spk_man) {
         result = spk_man->GetNewDestination(type, dest, error);
     }
     if (result) {
         SetAddressBook(dest, label, "receive");
     }
 
     return result;
 }
 
 bool CWallet::GetNewChangeDestination(const OutputType type,
                                       CTxDestination &dest,
                                       std::string &error) {
     error.clear();
 
     m_spk_man->TopUp();
 
     ReserveDestination reservedest(this);
     if (!reservedest.GetReservedDestination(type, dest, true)) {
         error = "Error: Keypool ran out, please call keypoolrefill first";
         return false;
     }
 
     reservedest.KeepDestination();
     return true;
 }
 
 int64_t CWallet::GetOldestKeyPoolTime() {
     int64_t oldestKey = std::numeric_limits<int64_t>::max();
     if (auto spk_man = m_spk_man.get()) {
         oldestKey = spk_man->GetOldestKeyPoolTime();
     }
     return oldestKey;
 }
 
 std::map<CTxDestination, Amount>
 CWallet::GetAddressBalances(interfaces::Chain::Lock &locked_chain) {
     std::map<CTxDestination, Amount> balances;
 
     LOCK(cs_wallet);
     for (const auto &walletEntry : mapWallet) {
         const CWalletTx &wtx = walletEntry.second;
 
         if (!wtx.IsTrusted(locked_chain)) {
             continue;
         }
 
         if (wtx.IsImmatureCoinBase(locked_chain)) {
             continue;
         }
 
         int nDepth = wtx.GetDepthInMainChain(locked_chain);
         if (nDepth < (wtx.IsFromMe(ISMINE_ALL) ? 0 : 1)) {
             continue;
         }
 
         for (uint32_t i = 0; i < wtx.tx->vout.size(); i++) {
             CTxDestination addr;
             if (!IsMine(wtx.tx->vout[i])) {
                 continue;
             }
 
             if (!ExtractDestination(wtx.tx->vout[i].scriptPubKey, addr)) {
                 continue;
             }
 
             Amount n = IsSpent(locked_chain, COutPoint(walletEntry.first, i))
                            ? Amount::zero()
                            : wtx.tx->vout[i].nValue;
 
             if (!balances.count(addr)) {
                 balances[addr] = Amount::zero();
             }
             balances[addr] += n;
         }
     }
 
     return balances;
 }
 
 std::set<std::set<CTxDestination>> CWallet::GetAddressGroupings() {
     AssertLockHeld(cs_wallet);
     std::set<std::set<CTxDestination>> groupings;
     std::set<CTxDestination> grouping;
 
     for (const auto &walletEntry : mapWallet) {
         const CWalletTx &wtx = walletEntry.second;
 
         if (wtx.tx->vin.size() > 0) {
             bool any_mine = false;
             // Group all input addresses with each other.
             for (const auto &txin : wtx.tx->vin) {
                 CTxDestination address;
                 // If this input isn't mine, ignore it.
                 if (!IsMine(txin)) {
                     continue;
                 }
 
                 if (!ExtractDestination(mapWallet.at(txin.prevout.GetTxId())
                                             .tx->vout[txin.prevout.GetN()]
                                             .scriptPubKey,
                                         address)) {
                     continue;
                 }
 
                 grouping.insert(address);
                 any_mine = true;
             }
 
             // Group change with input addresses.
             if (any_mine) {
                 for (const auto &txout : wtx.tx->vout) {
                     if (IsChange(txout)) {
                         CTxDestination txoutAddr;
                         if (!ExtractDestination(txout.scriptPubKey,
                                                 txoutAddr)) {
                             continue;
                         }
 
                         grouping.insert(txoutAddr);
                     }
                 }
             }
 
             if (grouping.size() > 0) {
                 groupings.insert(grouping);
                 grouping.clear();
             }
         }
 
         // Group lone addrs by themselves.
         for (const auto &txout : wtx.tx->vout) {
             if (IsMine(txout)) {
                 CTxDestination address;
                 if (!ExtractDestination(txout.scriptPubKey, address)) {
                     continue;
                 }
 
                 grouping.insert(address);
                 groupings.insert(grouping);
                 grouping.clear();
             }
         }
     }
 
     // A set of pointers to groups of addresses.
     std::set<std::set<CTxDestination> *> uniqueGroupings;
     // Map addresses to the unique group containing it.
     std::map<CTxDestination, std::set<CTxDestination> *> setmap;
     for (std::set<CTxDestination> _grouping : groupings) {
         // Make a set of all the groups hit by this new group.
         std::set<std::set<CTxDestination> *> hits;
         std::map<CTxDestination, std::set<CTxDestination> *>::iterator it;
         for (const CTxDestination &address : _grouping) {
             if ((it = setmap.find(address)) != setmap.end()) {
                 hits.insert((*it).second);
             }
         }
 
         // Merge all hit groups into a new single group and delete old groups.
         std::set<CTxDestination> *merged =
             new std::set<CTxDestination>(_grouping);
         for (std::set<CTxDestination> *hit : hits) {
             merged->insert(hit->begin(), hit->end());
             uniqueGroupings.erase(hit);
             delete hit;
         }
         uniqueGroupings.insert(merged);
 
         // Update setmap.
         for (const CTxDestination &element : *merged) {
             setmap[element] = merged;
         }
     }
 
     std::set<std::set<CTxDestination>> ret;
     for (const std::set<CTxDestination> *uniqueGrouping : uniqueGroupings) {
         ret.insert(*uniqueGrouping);
         delete uniqueGrouping;
     }
 
     return ret;
 }
 
 std::set<CTxDestination>
 CWallet::GetLabelAddresses(const std::string &label) const {
     LOCK(cs_wallet);
     std::set<CTxDestination> result;
     for (const std::pair<const CTxDestination, CAddressBookData> &item :
          mapAddressBook) {
         const CTxDestination &address = item.first;
         const std::string &strName = item.second.name;
         if (strName == label) {
             result.insert(address);
         }
     }
 
     return result;
 }
 
 bool ReserveDestination::GetReservedDestination(const OutputType type,
                                                 CTxDestination &dest,
                                                 bool internal) {
     m_spk_man = pwallet->GetLegacyScriptPubKeyMan();
     if (!m_spk_man) {
         return false;
     }
 
     if (!pwallet->CanGetAddresses(internal)) {
         return false;
     }
 
     if (nIndex == -1) {
         CKeyPool keypool;
         if (!m_spk_man->GetReservedDestination(type, internal, nIndex,
                                                keypool)) {
             return false;
         }
 
         vchPubKey = keypool.vchPubKey;
         fInternal = keypool.fInternal;
     }
 
     assert(vchPubKey.IsValid());
     m_spk_man->LearnRelatedScripts(vchPubKey, type);
     address = GetDestinationForKey(vchPubKey, type);
     dest = address;
     return true;
 }
 
 void ReserveDestination::KeepDestination() {
     if (nIndex != -1) {
         m_spk_man->KeepDestination(nIndex);
     }
 
     nIndex = -1;
     vchPubKey = CPubKey();
     address = CNoDestination();
 }
 
 void ReserveDestination::ReturnDestination() {
     if (nIndex != -1) {
         m_spk_man->ReturnDestination(nIndex, fInternal, vchPubKey);
     }
     nIndex = -1;
     vchPubKey = CPubKey();
     address = CNoDestination();
 }
 
 void CWallet::LockCoin(const COutPoint &output) {
     AssertLockHeld(cs_wallet);
     setLockedCoins.insert(output);
 }
 
 void CWallet::UnlockCoin(const COutPoint &output) {
     AssertLockHeld(cs_wallet);
     setLockedCoins.erase(output);
 }
 
 void CWallet::UnlockAllCoins() {
     AssertLockHeld(cs_wallet);
     setLockedCoins.clear();
 }
 
 bool CWallet::IsLockedCoin(const COutPoint &outpoint) const {
     AssertLockHeld(cs_wallet);
 
     return setLockedCoins.count(outpoint) > 0;
 }
 
 void CWallet::ListLockedCoins(std::vector<COutPoint> &vOutpts) const {
     AssertLockHeld(cs_wallet);
     for (COutPoint outpoint : setLockedCoins) {
         vOutpts.push_back(outpoint);
     }
 }
 
 /** @} */ // end of Actions
 
 void CWallet::GetKeyBirthTimes(interfaces::Chain::Lock &locked_chain,
                                std::map<CKeyID, int64_t> &mapKeyBirth) const {
     AssertLockHeld(cs_wallet);
     mapKeyBirth.clear();
 
     LegacyScriptPubKeyMan *spk_man = GetLegacyScriptPubKeyMan();
     assert(spk_man != nullptr);
     AssertLockHeld(spk_man->cs_wallet);
 
     // Get birth times for keys with metadata.
     for (const auto &entry : spk_man->mapKeyMetadata) {
         if (entry.second.nCreateTime) {
             mapKeyBirth[entry.first] = entry.second.nCreateTime;
         }
     }
 
     // Map in which we'll infer heights of other keys
     const Optional<int> tip_height = locked_chain.getHeight();
     // the tip can be reorganized; use a 144-block safety margin
     const int max_height =
         tip_height && *tip_height > 144 ? *tip_height - 144 : 0;
     std::map<CKeyID, int> mapKeyFirstBlock;
     for (const CKeyID &keyid : spk_man->GetKeys()) {
         if (mapKeyBirth.count(keyid) == 0) {
             mapKeyFirstBlock[keyid] = max_height;
         }
     }
 
     // If there are no such keys, we're done.
     if (mapKeyFirstBlock.empty()) {
         return;
     }
 
     // Find first block that affects those keys, if there are any left.
     for (const auto &entry : mapWallet) {
         // iterate over all wallet transactions...
         const CWalletTx &wtx = entry.second;
         if (Optional<int> height =
                 locked_chain.getBlockHeight(wtx.m_confirm.hashBlock)) {
             // ... which are already in a block
             for (const CTxOut &txout : wtx.tx->vout) {
                 // Iterate over all their outputs...
                 for (const auto &keyid :
                      GetAffectedKeys(txout.scriptPubKey, *spk_man)) {
                     // ... and all their affected keys.
                     std::map<CKeyID, int>::iterator rit =
                         mapKeyFirstBlock.find(keyid);
                     if (rit != mapKeyFirstBlock.end() &&
                         *height < rit->second) {
                         rit->second = *height;
                     }
                 }
             }
         }
     }
 
     // Extract block timestamps for those keys.
     for (const auto &entry : mapKeyFirstBlock) {
         // block times can be 2h off
         mapKeyBirth[entry.first] =
             locked_chain.getBlockTime(entry.second) - TIMESTAMP_WINDOW;
     }
 }
 
 /**
  * Compute smart timestamp for a transaction being added to the wallet.
  *
  * Logic:
  * - If sending a transaction, assign its timestamp to the current time.
  * - If receiving a transaction outside a block, assign its timestamp to the
  *   current time.
  * - If receiving a block with a future timestamp, assign all its (not already
  *   known) transactions' timestamps to the current time.
  * - If receiving a block with a past timestamp, before the most recent known
  *   transaction (that we care about), assign all its (not already known)
  *   transactions' timestamps to the same timestamp as that most-recent-known
  *   transaction.
  * - If receiving a block with a past timestamp, but after the most recent known
  *   transaction, assign all its (not already known) transactions' timestamps to
  *   the block time.
  *
  * For more information see CWalletTx::nTimeSmart,
  * https://bitcointalk.org/?topic=54527, or
  * https://github.com/bitcoin/bitcoin/pull/1393.
  */
 unsigned int CWallet::ComputeTimeSmart(const CWalletTx &wtx) const {
     unsigned int nTimeSmart = wtx.nTimeReceived;
     if (!wtx.isUnconfirmed() && !wtx.isAbandoned()) {
         int64_t blocktime;
         if (chain().findBlock(wtx.m_confirm.hashBlock, nullptr /* block */,
                               &blocktime)) {
             int64_t latestNow = wtx.nTimeReceived;
             int64_t latestEntry = 0;
 
             // Tolerate times up to the last timestamp in the wallet not more
             // than 5 minutes into the future
             int64_t latestTolerated = latestNow + 300;
             const TxItems &txOrdered = wtxOrdered;
             for (auto it = txOrdered.rbegin(); it != txOrdered.rend(); ++it) {
                 CWalletTx *const pwtx = it->second;
                 if (pwtx == &wtx) {
                     continue;
                 }
                 int64_t nSmartTime;
                 nSmartTime = pwtx->nTimeSmart;
                 if (!nSmartTime) {
                     nSmartTime = pwtx->nTimeReceived;
                 }
                 if (nSmartTime <= latestTolerated) {
                     latestEntry = nSmartTime;
                     if (nSmartTime > latestNow) {
                         latestNow = nSmartTime;
                     }
                     break;
                 }
             }
 
             nTimeSmart = std::max(latestEntry, std::min(blocktime, latestNow));
         } else {
             WalletLogPrintf("%s: found %s in block %s not in index\n", __func__,
                             wtx.GetId().ToString(),
                             wtx.m_confirm.hashBlock.ToString());
         }
     }
     return nTimeSmart;
 }
 
 bool CWallet::AddDestData(const CTxDestination &dest, const std::string &key,
                           const std::string &value) {
     if (boost::get<CNoDestination>(&dest)) {
         return false;
     }
 
     mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
     return WalletBatch(*database).WriteDestData(dest, key, value);
 }
 
 bool CWallet::EraseDestData(const CTxDestination &dest,
                             const std::string &key) {
     if (!mapAddressBook[dest].destdata.erase(key)) {
         return false;
     }
 
     return WalletBatch(*database).EraseDestData(dest, key);
 }
 
 void CWallet::LoadDestData(const CTxDestination &dest, const std::string &key,
                            const std::string &value) {
     mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
 }
 
 bool CWallet::GetDestData(const CTxDestination &dest, const std::string &key,
                           std::string *value) const {
     std::map<CTxDestination, CAddressBookData>::const_iterator i =
         mapAddressBook.find(dest);
     if (i != mapAddressBook.end()) {
         CAddressBookData::StringMap::const_iterator j =
             i->second.destdata.find(key);
         if (j != i->second.destdata.end()) {
             if (value) {
                 *value = j->second;
             }
 
             return true;
         }
     }
     return false;
 }
 
 std::vector<std::string>
 CWallet::GetDestValues(const std::string &prefix) const {
     std::vector<std::string> values;
     for (const auto &address : mapAddressBook) {
         for (const auto &data : address.second.destdata) {
             if (!data.first.compare(0, prefix.size(), prefix)) {
                 values.emplace_back(data.second);
             }
         }
     }
     return values;
 }
 
 bool CWallet::Verify(const CChainParams &chainParams, interfaces::Chain &chain,
                      const WalletLocation &location, bool salvage_wallet,
                      std::string &error_string,
                      std::vector<std::string> &warnings) {
     // Do some checking on wallet path. It should be either a:
     //
     // 1. Path where a directory can be created.
     // 2. Path to an existing directory.
     // 3. Path to a symlink to a directory.
     // 4. For backwards compatibility, the name of a data file in -walletdir.
     LOCK(cs_wallets);
     const fs::path &wallet_path = location.GetPath();
     fs::file_type path_type = fs::symlink_status(wallet_path).type();
     if (!(path_type == fs::file_not_found || path_type == fs::directory_file ||
           (path_type == fs::symlink_file && fs::is_directory(wallet_path)) ||
           (path_type == fs::regular_file &&
            fs::path(location.GetName()).filename() == location.GetName()))) {
         error_string =
             strprintf("Invalid -wallet path '%s'. -wallet path should point to "
                       "a directory where wallet.dat and "
                       "database/log.?????????? files can be stored, a location "
                       "where such a directory could be created, "
                       "or (for backwards compatibility) the name of an "
                       "existing data file in -walletdir (%s)",
                       location.GetName(), GetWalletDir());
         return false;
     }
 
     // Make sure that the wallet path doesn't clash with an existing wallet path
     if (IsWalletLoaded(wallet_path)) {
         error_string = strprintf(
             "Error loading wallet %s. Duplicate -wallet filename specified.",
             location.GetName());
         return false;
     }
 
     // Keep same database environment instance across Verify/Recover calls
     // below.
     std::unique_ptr<WalletDatabase> database =
         WalletDatabase::Create(wallet_path);
 
     try {
         if (!WalletBatch::VerifyEnvironment(wallet_path, error_string)) {
             return false;
         }
     } catch (const fs::filesystem_error &e) {
         error_string =
             strprintf("Error loading wallet %s. %s", location.GetName(),
                       fsbridge::get_filesystem_error_message(e));
         return false;
     }
 
     if (salvage_wallet) {
         // Recover readable keypairs:
         CWallet dummyWallet(chainParams, &chain, WalletLocation(),
                             WalletDatabase::CreateDummy());
         std::string backup_filename;
         // Even if we don't use this lock in this function, we want to preserve
         // lock order in LoadToWallet if query of chain state is needed to know
         // tx status. If lock can't be taken, tx confirmation status may be not
         // reliable.
         auto locked_chain = dummyWallet.LockChain();
         if (!WalletBatch::Recover(
                 wallet_path, static_cast<void *>(&dummyWallet),
                 WalletBatch::RecoverKeysOnlyFilter, backup_filename)) {
             return false;
         }
     }
 
     return WalletBatch::VerifyDatabaseFile(wallet_path, warnings, error_string);
 }
 
 std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(
     const CChainParams &chainParams, interfaces::Chain &chain,
     const WalletLocation &location, std::string &error,
     std::vector<std::string> &warnings, uint64_t wallet_creation_flags) {
     const std::string walletFile =
         WalletDataFilePath(location.GetPath()).string();
 
     // Needed to restore wallet transaction meta data after -zapwallettxes
     std::vector<CWalletTx> vWtx;
 
     if (gArgs.GetBoolArg("-zapwallettxes", false)) {
         chain.initMessage(
             _("Zapping all transactions from wallet...").translated);
 
         std::unique_ptr<CWallet> tempWallet = std::make_unique<CWallet>(
             chainParams, &chain, location,
             WalletDatabase::Create(location.GetPath()));
         DBErrors nZapWalletRet = tempWallet->ZapWalletTx(vWtx);
         if (nZapWalletRet != DBErrors::LOAD_OK) {
             error = strprintf(
                 _("Error loading %s: Wallet corrupted").translated, walletFile);
             return nullptr;
         }
     }
 
     chain.initMessage(_("Loading wallet...").translated);
 
     int64_t nStart = GetTimeMillis();
     bool fFirstRun = true;
     // TODO: Can't use std::make_shared because we need a custom deleter but
     // should be possible to use std::allocate_shared.
     std::shared_ptr<CWallet> walletInstance(
         new CWallet(chainParams, &chain, location,
                     WalletDatabase::Create(location.GetPath())),
         ReleaseWallet);
     DBErrors nLoadWalletRet = walletInstance->LoadWallet(fFirstRun);
     if (nLoadWalletRet != DBErrors::LOAD_OK) {
         if (nLoadWalletRet == DBErrors::CORRUPT) {
             error = strprintf(
                 _("Error loading %s: Wallet corrupted").translated, walletFile);
             return nullptr;
         }
 
         if (nLoadWalletRet == DBErrors::NONCRITICAL_ERROR) {
             warnings.push_back(strprintf(
                 _("Error reading %s! All keys read correctly, but transaction "
                   "data or address book entries might be missing or incorrect.")
                     .translated,
                 walletFile));
         } else if (nLoadWalletRet == DBErrors::TOO_NEW) {
             error = strprintf(
                 _("Error loading %s: Wallet requires newer version of %s")
                     .translated,
                 walletFile, PACKAGE_NAME);
             return nullptr;
         } else if (nLoadWalletRet == DBErrors::NEED_REWRITE) {
             error = strprintf(
                 _("Wallet needed to be rewritten: restart %s to complete")
                     .translated,
                 PACKAGE_NAME);
             return nullptr;
         } else {
             error = strprintf(_("Error loading %s").translated, walletFile);
             return nullptr;
         }
     }
 
     int prev_version = walletInstance->GetVersion();
     if (gArgs.GetBoolArg("-upgradewallet", fFirstRun)) {
         int nMaxVersion = gArgs.GetArg("-upgradewallet", 0);
         // The -upgradewallet without argument case
         if (nMaxVersion == 0) {
             walletInstance->WalletLogPrintf("Performing wallet upgrade to %i\n",
                                             FEATURE_LATEST);
             nMaxVersion = FEATURE_LATEST;
             // permanently upgrade the wallet immediately
             walletInstance->SetMinVersion(FEATURE_LATEST);
         } else {
             walletInstance->WalletLogPrintf(
                 "Allowing wallet upgrade up to %i\n", nMaxVersion);
         }
 
         if (nMaxVersion < walletInstance->GetVersion()) {
             error = _("Cannot downgrade wallet").translated;
             return nullptr;
         }
 
         walletInstance->SetMaxVersion(nMaxVersion);
     }
 
     // Upgrade to HD if explicit upgrade
     if (gArgs.GetBoolArg("-upgradewallet", false)) {
         LOCK(walletInstance->cs_wallet);
 
         // Do not upgrade versions to any version between HD_SPLIT and
         // FEATURE_PRE_SPLIT_KEYPOOL unless already supporting HD_SPLIT
         int max_version = walletInstance->GetVersion();
         if (!walletInstance->CanSupportFeature(FEATURE_HD_SPLIT) &&
             max_version >= FEATURE_HD_SPLIT &&
             max_version < FEATURE_PRE_SPLIT_KEYPOOL) {
             error =
                 _("Cannot upgrade a non HD split wallet without upgrading to "
                   "support pre split keypool. Please use -upgradewallet=200300 "
                   "or -upgradewallet with no version specified.")
                     .translated;
             return nullptr;
         }
 
         if (auto spk_man = walletInstance->m_spk_man.get()) {
             if (!spk_man->Upgrade(prev_version, error)) {
                 chain.initError(error);
                 return nullptr;
             }
         }
     }
 
     if (fFirstRun) {
         // Ensure this wallet.dat can only be opened by clients supporting
         // HD with chain split and expects no default key.
         walletInstance->SetMinVersion(FEATURE_LATEST);
 
         walletInstance->SetWalletFlags(wallet_creation_flags, false);
         if (!(wallet_creation_flags &
               (WALLET_FLAG_DISABLE_PRIVATE_KEYS | WALLET_FLAG_BLANK_WALLET))) {
             if (auto spk_man = walletInstance->m_spk_man.get()) {
                 if (!spk_man->SetupGeneration()) {
                     error = _("Unable to generate initial keys").translated;
                     return nullptr;
                 }
             }
         }
 
         auto locked_chain = chain.lock();
         walletInstance->ChainStateFlushed(locked_chain->getTipLocator());
     } else if (wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS) {
         // Make it impossible to disable private keys after creation
         error = strprintf(_("Error loading %s: Private keys can only be "
                             "disabled during creation")
                               .translated,
                           walletFile);
         return nullptr;
     } else if (walletInstance->IsWalletFlagSet(
                    WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
         if (walletInstance->m_spk_man) {
             if (walletInstance->m_spk_man->HavePrivateKeys()) {
                 warnings.push_back(
                     strprintf(_("Warning: Private keys detected in wallet {%s} "
                                 "with disabled private keys")
                                   .translated,
                               walletFile));
             }
         }
     }
 
     if (gArgs.IsArgSet("-mintxfee")) {
         Amount n = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-mintxfee", ""), n) ||
             n == Amount::zero()) {
             error = AmountErrMsg("mintxfee", gArgs.GetArg("-mintxfee", ""))
                         .translated;
             return nullptr;
         }
         if (n > HIGH_TX_FEE_PER_KB) {
             warnings.push_back(AmountHighWarn("-mintxfee").translated + " " +
                                _("This is the minimum transaction fee you pay "
                                  "on every transaction.")
                                    .translated);
         }
         walletInstance->m_min_fee = CFeeRate(n);
     }
 
     if (gArgs.IsArgSet("-fallbackfee")) {
         Amount nFeePerK = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-fallbackfee", ""), nFeePerK)) {
             error = strprintf(
                 _("Invalid amount for -fallbackfee=<amount>: '%s'").translated,
                 gArgs.GetArg("-fallbackfee", ""));
             return nullptr;
         }
         if (nFeePerK > HIGH_TX_FEE_PER_KB) {
             warnings.push_back(AmountHighWarn("-fallbackfee").translated + " " +
                                _("This is the transaction fee you may pay when "
                                  "fee estimates are not available.")
                                    .translated);
         }
         walletInstance->m_fallback_fee = CFeeRate(nFeePerK);
     }
     // Disable fallback fee in case value was set to 0, enable if non-null value
     walletInstance->m_allow_fallback_fee =
         walletInstance->m_fallback_fee.GetFeePerK() != Amount::zero();
 
     if (gArgs.IsArgSet("-paytxfee")) {
         Amount nFeePerK = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-paytxfee", ""), nFeePerK)) {
             error = AmountErrMsg("paytxfee", gArgs.GetArg("-paytxfee", ""))
                         .translated;
             return nullptr;
         }
         if (nFeePerK > HIGH_TX_FEE_PER_KB) {
             warnings.push_back(AmountHighWarn("-paytxfee").translated + " " +
                                _("This is the transaction fee you will pay if "
                                  "you send a transaction.")
                                    .translated);
         }
         walletInstance->m_pay_tx_fee = CFeeRate(nFeePerK, 1000);
         if (walletInstance->m_pay_tx_fee < chain.relayMinFee()) {
             error = strprintf(_("Invalid amount for -paytxfee=<amount>: '%s' "
                                 "(must be at least %s)")
                                   .translated,
                               gArgs.GetArg("-paytxfee", ""),
                               chain.relayMinFee().ToString());
             return nullptr;
         }
     }
 
     if (gArgs.IsArgSet("-maxtxfee")) {
         Amount nMaxFee = Amount::zero();
         if (!ParseMoney(gArgs.GetArg("-maxtxfee", ""), nMaxFee)) {
             error = AmountErrMsg("maxtxfee", gArgs.GetArg("-maxtxfee", ""))
                         .translated;
             return nullptr;
         }
         if (nMaxFee > HIGH_MAX_TX_FEE) {
             warnings.push_back(_("-maxtxfee is set very high! Fees this large "
                                  "could be paid on a single transaction.")
                                    .translated);
         }
         if (CFeeRate(nMaxFee, 1000) < chain.relayMinFee()) {
             error = strprintf(
                 _("Invalid amount for -maxtxfee=<amount>: '%s' (must be at "
                   "least the minrelay fee of %s to prevent stuck transactions)")
                     .translated,
                 gArgs.GetArg("-maxtxfee", ""), chain.relayMinFee().ToString());
             return nullptr;
         }
         walletInstance->m_default_max_tx_fee = nMaxFee;
     }
 
     if (chain.relayMinFee().GetFeePerK() > HIGH_TX_FEE_PER_KB) {
         warnings.push_back(
             AmountHighWarn("-minrelaytxfee").translated + " " +
             _("The wallet will avoid paying less than the minimum relay fee.")
                 .translated);
     }
 
     walletInstance->m_spend_zero_conf_change =
         gArgs.GetBoolArg("-spendzeroconfchange", DEFAULT_SPEND_ZEROCONF_CHANGE);
 
     walletInstance->m_default_address_type = DEFAULT_ADDRESS_TYPE;
     walletInstance->m_default_change_type = DEFAULT_CHANGE_TYPE;
 
     walletInstance->WalletLogPrintf("Wallet completed loading in %15dms\n",
                                     GetTimeMillis() - nStart);
 
     // Try to top up keypool. No-op if the wallet is locked.
     walletInstance->TopUpKeyPool();
 
     auto locked_chain = chain.lock();
     LOCK(walletInstance->cs_wallet);
 
     int rescan_height = 0;
     if (!gArgs.GetBoolArg("-rescan", false)) {
         WalletBatch batch(*walletInstance->database);
         CBlockLocator locator;
         if (batch.ReadBestBlock(locator)) {
             if (const Optional<int> fork_height =
                     locked_chain->findLocatorFork(locator)) {
                 rescan_height = *fork_height;
             }
         }
     }
 
     const Optional<int> tip_height = locked_chain->getHeight();
     if (tip_height) {
         walletInstance->m_last_block_processed =
             locked_chain->getBlockHash(*tip_height);
+        walletInstance->m_last_block_processed_height = *tip_height;
     } else {
         walletInstance->m_last_block_processed.SetNull();
+        walletInstance->m_last_block_processed_height = -1;
     }
 
     if (tip_height && *tip_height != rescan_height) {
         // We can't rescan beyond non-pruned blocks, stop and throw an error.
         // This might happen if a user uses an old wallet within a pruned node
         // or if they ran -disablewallet for a longer time, then decided to
         // re-enable
         if (chain.havePruned()) {
             // Exit early and print an error.
             // If a block is pruned after this check, we will load the wallet,
             // but fail the rescan with a generic error.
             int block_height = *tip_height;
             while (block_height > 0 &&
                    locked_chain->haveBlockOnDisk(block_height - 1) &&
                    rescan_height != block_height) {
                 --block_height;
             }
 
             if (rescan_height != block_height) {
                 error = _("Prune: last wallet synchronisation goes beyond "
                           "pruned data. You need to -reindex (download the "
                           "whole blockchain again in case of pruned node)")
                             .translated;
                 return nullptr;
             }
         }
 
         chain.initMessage(_("Rescanning...").translated);
         walletInstance->WalletLogPrintf(
             "Rescanning last %i blocks (from block %i)...\n",
             *tip_height - rescan_height, rescan_height);
 
         // No need to read and scan block if block was created before our wallet
         // birthday (as adjusted for block time variability)
         Optional<int64_t> time_first_key;
         if (auto spk_man = walletInstance->m_spk_man.get()) {
             int64_t time = spk_man->GetTimeFirstKey();
             if (!time_first_key || time < *time_first_key) {
                 time_first_key = time;
             }
         }
         if (time_first_key) {
             if (Optional<int> first_block =
                     locked_chain->findFirstBlockWithTimeAndHeight(
                         *time_first_key - TIMESTAMP_WINDOW, rescan_height,
                         nullptr)) {
                 rescan_height = *first_block;
             }
         }
 
         {
             WalletRescanReserver reserver(walletInstance.get());
             if (!reserver.reserve() ||
                 (ScanResult::SUCCESS !=
                  walletInstance
                      ->ScanForWalletTransactions(
                          locked_chain->getBlockHash(rescan_height), BlockHash(),
                          reserver, true /* update */)
                      .status)) {
                 error = _("Failed to rescan the wallet during initialization")
                             .translated;
                 return nullptr;
             }
         }
         walletInstance->ChainStateFlushed(locked_chain->getTipLocator());
         walletInstance->database->IncrementUpdateCounter();
 
         // Restore wallet transaction metadata after -zapwallettxes=1
         if (gArgs.GetBoolArg("-zapwallettxes", false) &&
             gArgs.GetArg("-zapwallettxes", "1") != "2") {
             WalletBatch batch(*walletInstance->database);
 
             for (const CWalletTx &wtxOld : vWtx) {
                 const TxId txid = wtxOld.GetId();
                 std::map<TxId, CWalletTx>::iterator mi =
                     walletInstance->mapWallet.find(txid);
                 if (mi != walletInstance->mapWallet.end()) {
                     const CWalletTx *copyFrom = &wtxOld;
                     CWalletTx *copyTo = &mi->second;
                     copyTo->mapValue = copyFrom->mapValue;
                     copyTo->vOrderForm = copyFrom->vOrderForm;
                     copyTo->nTimeReceived = copyFrom->nTimeReceived;
                     copyTo->nTimeSmart = copyFrom->nTimeSmart;
                     copyTo->fFromMe = copyFrom->fFromMe;
                     copyTo->nOrderPos = copyFrom->nOrderPos;
                     batch.WriteTx(*copyTo);
                 }
             }
         }
     }
 
     chain.loadWallet(interfaces::MakeWallet(walletInstance));
 
     // Register with the validation interface. It's ok to do this after rescan
     // since we're still holding locked_chain.
     walletInstance->m_chain_notifications_handler =
         walletInstance->chain().handleNotifications(walletInstance);
 
     walletInstance->SetBroadcastTransactions(
         gArgs.GetBoolArg("-walletbroadcast", DEFAULT_WALLETBROADCAST));
 
     walletInstance->WalletLogPrintf("setKeyPool.size() = %u\n",
                                     walletInstance->GetKeyPoolSize());
     walletInstance->WalletLogPrintf("mapWallet.size() = %u\n",
                                     walletInstance->mapWallet.size());
     walletInstance->WalletLogPrintf("mapAddressBook.size() = %u\n",
                                     walletInstance->mapAddressBook.size());
 
     return walletInstance;
 }
 
 void CWallet::postInitProcess() {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     // Add wallet transactions that aren't already in a block to mempool.
     // Do this here as mempool requires genesis block to be loaded.
     ReacceptWalletTransactions(*locked_chain);
 
     // Update wallet transactions with current mempool transactions.
     chain().requestMempoolTransactions(*this);
 }
 
 bool CWallet::BackupWallet(const std::string &strDest) {
     return database->Backup(strDest);
 }
 
 CKeyPool::CKeyPool() {
     nTime = GetTime();
     fInternal = false;
     m_pre_split = false;
 }
 
 CKeyPool::CKeyPool(const CPubKey &vchPubKeyIn, bool internalIn) {
     nTime = GetTime();
     vchPubKey = vchPubKeyIn;
     fInternal = internalIn;
     m_pre_split = false;
 }
 
 void CWalletTx::SetConf(Status status, const BlockHash &block_hash,
                         int posInBlock) {
     // Update tx status
     m_confirm.status = status;
 
     // Update the tx's hashBlock
     m_confirm.hashBlock = block_hash;
 
     // Set the position of the transaction in the block.
     m_confirm.nIndex = posInBlock;
 }
 
 int CWalletTx::GetDepthInMainChain(
     interfaces::Chain::Lock &locked_chain) const {
     if (isUnconfirmed() || isAbandoned()) {
         return 0;
     }
 
     return locked_chain.getBlockDepth(m_confirm.hashBlock) *
            (isConflicted() ? -1 : 1);
 }
 
 int CWalletTx::GetBlocksToMaturity(
     interfaces::Chain::Lock &locked_chain) const {
     if (!IsCoinBase()) {
         return 0;
     }
 
     int chain_depth = GetDepthInMainChain(locked_chain);
     // coinbase tx should not be conflicted
     assert(chain_depth >= 0);
     return std::max(0, (COINBASE_MATURITY + 1) - chain_depth);
 }
 
 bool CWalletTx::IsImmatureCoinBase(
     interfaces::Chain::Lock &locked_chain) const {
     // note GetBlocksToMaturity is 0 for non-coinbase tx
     return GetBlocksToMaturity(locked_chain) > 0;
 }
 
 std::vector<OutputGroup>
 CWallet::GroupOutputs(const std::vector<COutput> &outputs,
                       bool single_coin) const {
     std::vector<OutputGroup> groups;
     std::map<CTxDestination, OutputGroup> gmap;
     CTxDestination dst;
     for (const auto &output : outputs) {
         if (output.fSpendable) {
             CInputCoin input_coin = output.GetInputCoin();
 
             size_t ancestors, descendants;
             chain().getTransactionAncestry(output.tx->GetId(), ancestors,
                                            descendants);
             if (!single_coin &&
                 ExtractDestination(output.tx->tx->vout[output.i].scriptPubKey,
                                    dst)) {
                 // Limit output groups to no more than 10 entries, to protect
                 // against inadvertently creating a too-large transaction
                 // when using -avoidpartialspends
                 if (gmap[dst].m_outputs.size() >= OUTPUT_GROUP_MAX_ENTRIES) {
                     groups.push_back(gmap[dst]);
                     gmap.erase(dst);
                 }
                 gmap[dst].Insert(input_coin, output.nDepth,
                                  output.tx->IsFromMe(ISMINE_ALL), ancestors,
                                  descendants);
             } else {
                 groups.emplace_back(input_coin, output.nDepth,
                                     output.tx->IsFromMe(ISMINE_ALL), ancestors,
                                     descendants);
             }
         }
     }
     if (!single_coin) {
         for (const auto &it : gmap) {
             groups.push_back(it.second);
         }
     }
     return groups;
 }
 
 bool CWallet::SetCrypted() {
     LOCK(cs_KeyStore);
     if (fUseCrypto) {
         return true;
     }
     if (!mapKeys.empty()) {
         return false;
     }
     fUseCrypto = true;
     return true;
 }
 
 bool CWallet::IsLocked() const {
     if (!IsCrypted()) {
         return false;
     }
     LOCK(cs_KeyStore);
     return vMasterKey.empty();
 }
 
 bool CWallet::Lock() {
     if (!SetCrypted()) {
         return false;
     }
 
     {
         LOCK(cs_KeyStore);
         vMasterKey.clear();
     }
 
     NotifyStatusChanged(this);
     return true;
 }
 
 ScriptPubKeyMan *CWallet::GetScriptPubKeyMan() const {
     return m_spk_man.get();
 }
 
 const SigningProvider *CWallet::GetSigningProvider() const {
     return m_spk_man.get();
 }
 
 LegacyScriptPubKeyMan *CWallet::GetLegacyScriptPubKeyMan() const {
     return m_spk_man.get();
 }
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index f620e116e..8ac6cb18d 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -1,1423 +1,1444 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Copyright (c) 2018-2020 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_WALLET_WALLET_H
 #define BITCOIN_WALLET_WALLET_H
 
 #include <amount.h>
 #include <interfaces/chain.h>
 #include <interfaces/handler.h>
 #include <outputtype.h>
 #include <primitives/blockhash.h>
 #include <tinyformat.h>
 #include <ui_interface.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <validationinterface.h>
 #include <wallet/coinselection.h>
 #include <wallet/crypter.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/scriptpubkeyman.h>
 #include <wallet/walletdb.h>
 #include <wallet/walletutil.h>
 
 #include <algorithm>
 #include <atomic>
 #include <cstdint>
 #include <map>
 #include <memory>
 #include <set>
 #include <stdexcept>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include <boost/signals2/signal.hpp>
 
 //! Explicitly unload and delete the wallet.
 //! Blocks the current thread after signaling the unload intent so that all
 //! wallet clients release the wallet.
 //! Note that, when blocking is not required, the wallet is implicitly unloaded
 //! by the shared pointer deleter.
 void UnloadWallet(std::shared_ptr<CWallet> &&wallet);
 
 bool AddWallet(const std::shared_ptr<CWallet> &wallet);
 bool RemoveWallet(const std::shared_ptr<CWallet> &wallet);
 bool HasWallets();
 std::vector<std::shared_ptr<CWallet>> GetWallets();
 std::shared_ptr<CWallet> GetWallet(const std::string &name);
 std::shared_ptr<CWallet> LoadWallet(const CChainParams &chainParams,
                                     interfaces::Chain &chain,
                                     const WalletLocation &location,
                                     std::string &error,
                                     std::vector<std::string> &warnings);
 
 enum class WalletCreationStatus { SUCCESS, CREATION_FAILED, ENCRYPTION_FAILED };
 
 WalletCreationStatus CreateWallet(const CChainParams &params,
                                   interfaces::Chain &chain,
                                   const SecureString &passphrase,
                                   uint64_t wallet_creation_flags,
                                   const std::string &name, std::string &error,
                                   std::vector<std::string> &warnings,
                                   std::shared_ptr<CWallet> &result);
 
 //! -paytxfee default
 constexpr Amount DEFAULT_PAY_TX_FEE = Amount::zero();
 //! -fallbackfee default
 static const Amount DEFAULT_FALLBACK_FEE = Amount::zero();
 //! -mintxfee default
 static const Amount DEFAULT_TRANSACTION_MINFEE_PER_KB = 1000 * SATOSHI;
 //! minimum recommended increment for BIP 125 replacement txs
 static const Amount WALLET_INCREMENTAL_RELAY_FEE(5000 * SATOSHI);
 //! Default for -spendzeroconfchange
 static const bool DEFAULT_SPEND_ZEROCONF_CHANGE = true;
 //! Default for -walletrejectlongchains
 static const bool DEFAULT_WALLET_REJECT_LONG_CHAINS = false;
 //! Default for -avoidpartialspends
 static const bool DEFAULT_AVOIDPARTIALSPENDS = false;
 static const bool DEFAULT_WALLETBROADCAST = true;
 static const bool DEFAULT_DISABLE_WALLET = false;
 //! -maxtxfee default
 constexpr Amount DEFAULT_TRANSACTION_MAXFEE{COIN / 10};
 //! Discourage users to set fees higher than this amount (in satoshis) per kB
 constexpr Amount HIGH_TX_FEE_PER_KB{COIN / 100};
 //! -maxtxfee will warn if called with a higher fee than this amount (in
 //! satoshis)
 constexpr Amount HIGH_MAX_TX_FEE{100 * HIGH_TX_FEE_PER_KB};
 
 class CChainParams;
 class CCoinControl;
 class COutput;
 class CScript;
 class CTxMemPool;
 class CWalletTx;
 class ReserveDestination;
 
 //! Default for -addresstype
 constexpr OutputType DEFAULT_ADDRESS_TYPE{OutputType::LEGACY};
 
 //! Default for -changetype
 constexpr OutputType DEFAULT_CHANGE_TYPE{OutputType::CHANGE_AUTO};
 
 static constexpr uint64_t KNOWN_WALLET_FLAGS =
     WALLET_FLAG_AVOID_REUSE | WALLET_FLAG_BLANK_WALLET |
     WALLET_FLAG_KEY_ORIGIN_METADATA | WALLET_FLAG_DISABLE_PRIVATE_KEYS;
 
 static constexpr uint64_t MUTABLE_WALLET_FLAGS = WALLET_FLAG_AVOID_REUSE;
 
 static const std::map<std::string, WalletFlags> WALLET_FLAG_MAP{
     {"avoid_reuse", WALLET_FLAG_AVOID_REUSE},
     {"blank", WALLET_FLAG_BLANK_WALLET},
     {"key_origin_metadata", WALLET_FLAG_KEY_ORIGIN_METADATA},
     {"disable_private_keys", WALLET_FLAG_DISABLE_PRIVATE_KEYS},
 };
 
 extern const std::map<uint64_t, std::string> WALLET_FLAG_CAVEATS;
 
 /**
  * A wrapper to reserve an address from a wallet
  *
  * ReserveDestination is used to reserve an address.
  * It is currently only used inside of CreateTransaction.
  *
  * Instantiating a ReserveDestination does not reserve an address. To do so,
  * GetReservedDestination() needs to be called on the object. Once an address
  * has been reserved, call KeepDestination() on the ReserveDestination object to
  * make sure it is not returned. Call ReturnDestination() to return the address
  * so it can be re-used (for example, if the address was used in a new
  * transaction and that transaction was not completed and needed to be aborted).
  *
  * If an address is reserved and KeepDestination() is not called, then the
  * address will be returned when the ReserveDestination goes out of scope.
  */
 class ReserveDestination {
 protected:
     //! The wallet to reserve from
     CWallet *pwallet;
     LegacyScriptPubKeyMan *m_spk_man{nullptr};
     //! The index of the address's key in the keypool
     int64_t nIndex{-1};
     //! The public key for the address
     CPubKey vchPubKey;
     //! The destination
     CTxDestination address;
     //! Whether this is from the internal (change output) keypool
     bool fInternal{false};
 
 public:
     //! Construct a ReserveDestination object. This does NOT reserve an address
     //! yet
     explicit ReserveDestination(CWallet *pwalletIn) { pwallet = pwalletIn; }
 
     ReserveDestination(const ReserveDestination &) = delete;
     ReserveDestination &operator=(const ReserveDestination &) = delete;
 
     //! Destructor. If a key has been reserved and not KeepKey'ed, it will be
     //! returned to the keypool
     ~ReserveDestination() { ReturnDestination(); }
 
     //! Reserve an address
     bool GetReservedDestination(const OutputType type, CTxDestination &pubkey,
                                 bool internal);
     //! Return reserved address
     void ReturnDestination();
     //! Keep the address. Do not return it's key to the keypool when this object
     //! goes out of scope
     void KeepDestination();
 };
 
 /** Address book data */
 class CAddressBookData {
 public:
     std::string name;
     std::string purpose;
 
     CAddressBookData() : purpose("unknown") {}
 
     typedef std::map<std::string, std::string> StringMap;
     StringMap destdata;
 };
 
 struct CRecipient {
     CScript scriptPubKey;
     Amount nAmount;
     bool fSubtractFeeFromAmount;
 };
 
 typedef std::map<std::string, std::string> mapValue_t;
 
 static inline void ReadOrderPos(int64_t &nOrderPos, mapValue_t &mapValue) {
     if (!mapValue.count("n")) {
         // TODO: calculate elsewhere
         nOrderPos = -1;
         return;
     }
 
     nOrderPos = atoi64(mapValue["n"].c_str());
 }
 
 static inline void WriteOrderPos(const int64_t &nOrderPos,
                                  mapValue_t &mapValue) {
     if (nOrderPos == -1) {
         return;
     }
     mapValue["n"] = i64tostr(nOrderPos);
 }
 
 struct COutputEntry {
     CTxDestination destination;
     Amount amount;
     int vout;
 };
 
 /**
  * Legacy class used for deserializing vtxPrev for backwards compatibility.
  * vtxPrev was removed in commit 93a18a3650292afbb441a47d1fa1b94aeb0164e3,
  * but old wallet.dat files may still contain vtxPrev vectors of CMerkleTxs.
  * These need to get deserialized for field alignment when deserializing
  * a CWalletTx, but the deserialized values are discarded.
  */
 class CMerkleTx {
 public:
     template <typename Stream> void Unserialize(Stream &s) {
         CTransactionRef tx;
         BlockHash hashBlock;
         std::vector<uint256> vMerkleBranch;
         int nIndex = 0;
 
         s >> tx >> hashBlock >> vMerkleBranch >> nIndex;
     }
 };
 
 // Get the marginal bytes of spending the specified output
 int CalculateMaximumSignedInputSize(const CTxOut &txout, const CWallet *pwallet,
                                     bool use_max_sig = false);
 
 /**
  * A transaction with a bunch of additional info that only the owner cares
  * about. It includes any unrecorded transactions needed to link it back to the
  * block chain.
  */
 class CWalletTx {
 private:
     const CWallet *pwallet;
 
     /**
      * Constant used in hashBlock to indicate tx has been abandoned, only used
      * at serialization/deserialization to avoid ambiguity with conflicted.
      */
     static const BlockHash ABANDON_HASH;
 
 public:
     /**
      * Key/value map with information about the transaction.
      *
      * The following keys can be read and written through the map and are
      * serialized in the wallet database:
      *
      *     "comment", "to"   - comment strings provided to sendtoaddress,
      *                         and sendmany wallet RPCs
      *     "replaces_txid"   - txid (as HexStr) of transaction replaced by
      *                         bumpfee on transaction created by bumpfee
      *     "replaced_by_txid" - txid (as HexStr) of transaction created by
      *                         bumpfee on transaction replaced by bumpfee
      *     "from", "message" - obsolete fields that could be set in UI prior to
      *                         2011 (removed in commit 4d9b223)
      *
      * The following keys are serialized in the wallet database, but shouldn't
      * be read or written through the map (they will be temporarily added and
      * removed from the map during serialization):
      *
      *     "fromaccount"     - serialized strFromAccount value
      *     "n"               - serialized nOrderPos value
      *     "timesmart"       - serialized nTimeSmart value
      *     "spent"           - serialized vfSpent value that existed prior to
      *                         2014 (removed in commit 93a18a3)
      */
     mapValue_t mapValue;
     std::vector<std::pair<std::string, std::string>> vOrderForm;
     unsigned int fTimeReceivedIsTxTime;
     //! time received by this node
     unsigned int nTimeReceived;
     /**
      * Stable timestamp that never changes, and reflects the order a transaction
      * was added to the wallet. Timestamp is based on the block time for a
      * transaction added as part of a block, or else the time when the
      * transaction was received if it wasn't part of a block, with the timestamp
      * adjusted in both cases so timestamp order matches the order transactions
      * were added to the wallet. More details can be found in
      * CWallet::ComputeTimeSmart().
      */
     unsigned int nTimeSmart;
     /**
      * From me flag is set to 1 for transactions that were created by the wallet
      * on this bitcoin node, and set to 0 for transactions that were created
      * externally and came in through the network or sendrawtransaction RPC.
      */
     bool fFromMe;
     //! position in ordered transaction list
     int64_t nOrderPos;
     std::multimap<int64_t, CWalletTx *>::const_iterator m_it_wtxOrdered;
 
     // memory only
     enum AmountType {
         DEBIT,
         CREDIT,
         IMMATURE_CREDIT,
         AVAILABLE_CREDIT,
         AMOUNTTYPE_ENUM_ELEMENTS
     };
     Amount GetCachableAmount(AmountType type, const isminefilter &filter,
                              bool recalculate = false) const;
     mutable CachableAmount m_amounts[AMOUNTTYPE_ENUM_ELEMENTS];
     mutable bool fChangeCached;
     mutable bool fInMempool;
     mutable Amount nChangeCached;
 
     CWalletTx(const CWallet *pwalletIn, CTransactionRef arg)
         : tx(std::move(arg)) {
         Init(pwalletIn);
     }
 
     void Init(const CWallet *pwalletIn) {
         pwallet = pwalletIn;
         mapValue.clear();
         vOrderForm.clear();
         fTimeReceivedIsTxTime = false;
         nTimeReceived = 0;
         nTimeSmart = 0;
         fFromMe = false;
         fChangeCached = false;
         fInMempool = false;
         nChangeCached = Amount::zero();
         nOrderPos = -1;
         m_confirm = Confirmation{};
     }
 
     CTransactionRef tx;
 
     /**
      * New transactions start as UNCONFIRMED. At BlockConnected,
      * they will transition to CONFIRMED. In case of reorg, at
      * BlockDisconnected, they roll back to UNCONFIRMED. If we detect a
      * conflicting transaction at block connection, we update conflicted tx and
      * its dependencies as CONFLICTED. If tx isn't confirmed and outside of
      * mempool, the user may switch it to ABANDONED by using the
      * abandontransaction call. This last status may be override by a CONFLICTED
      * or CONFIRMED transition.
      */
     enum Status { UNCONFIRMED, CONFIRMED, CONFLICTED, ABANDONED };
 
     /**
      * Confirmation includes tx status and a pair of {block hash/tx index in
      * block} at which tx has been confirmed. This pair is both 0 if tx hasn't
      * confirmed yet. Meaning of these fields changes with CONFLICTED state
      * where they instead point to block hash and index of the deepest
      * conflicting tx.
      */
     struct Confirmation {
         Status status = UNCONFIRMED;
         BlockHash hashBlock = BlockHash();
         int nIndex = 0;
     };
 
     Confirmation m_confirm;
 
     template <typename Stream> void Serialize(Stream &s) const {
         mapValue_t mapValueCopy = mapValue;
 
         mapValueCopy["fromaccount"] = "";
         WriteOrderPos(nOrderPos, mapValueCopy);
         if (nTimeSmart) {
             mapValueCopy["timesmart"] = strprintf("%u", nTimeSmart);
         }
 
         //! Used to be vMerkleBranch
         std::vector<char> dummy_vector1;
         //! Used to be vtxPrev
         std::vector<char> dummy_vector2;
         //! Used to be fSpent
         bool dummy_bool = false;
         uint256 serializedHash =
             isAbandoned() ? ABANDON_HASH : m_confirm.hashBlock;
         int serializedIndex =
             isAbandoned() || isConflicted() ? -1 : m_confirm.nIndex;
         s << tx << serializedHash << dummy_vector1 << serializedIndex
           << dummy_vector2 << mapValueCopy << vOrderForm
           << fTimeReceivedIsTxTime << nTimeReceived << fFromMe << dummy_bool;
     }
 
     template <typename Stream> void Unserialize(Stream &s) {
         Init(nullptr);
 
         //! Used to be vMerkleBranch
         std::vector<uint256> dummy_vector1;
         //! Used to be vtxPrev
         std::vector<CMerkleTx> dummy_vector2;
         //! Used to be fSpent
         bool dummy_bool;
         int serializedIndex;
         s >> tx >> m_confirm.hashBlock >> dummy_vector1 >> serializedIndex >>
             dummy_vector2 >> mapValue >> vOrderForm >> fTimeReceivedIsTxTime >>
             nTimeReceived >> fFromMe >> dummy_bool;
 
         /*
          * At serialization/deserialization, an nIndex == -1 means that
          * hashBlock refers to the earliest block in the chain we know this or
          * any in-wallet ancestor conflicts with. If nIndex == -1 and hashBlock
          * is ABANDON_HASH, it means transaction is abandoned. In same context,
          * an nIndex >= 0 refers to a confirmed transaction (if hashBlock set)
          * or unconfirmed one. Older clients interpret nIndex == -1 as
          * unconfirmed for backward compatibility (pre-commit 9ac63d6).
          */
         if (serializedIndex == -1 && m_confirm.hashBlock == ABANDON_HASH) {
             m_confirm.hashBlock = BlockHash();
             setAbandoned();
         } else if (serializedIndex == -1) {
             setConflicted();
         } else if (!m_confirm.hashBlock.IsNull()) {
             m_confirm.nIndex = serializedIndex;
             setConfirmed();
         }
 
         ReadOrderPos(nOrderPos, mapValue);
         nTimeSmart = mapValue.count("timesmart")
                          ? (unsigned int)atoi64(mapValue["timesmart"])
                          : 0;
 
         mapValue.erase("fromaccount");
         mapValue.erase("spent");
         mapValue.erase("n");
         mapValue.erase("timesmart");
     }
 
     void SetTx(CTransactionRef arg) { tx = std::move(arg); }
 
     //! make sure balances are recalculated
     void MarkDirty() {
         m_amounts[DEBIT].Reset();
         m_amounts[CREDIT].Reset();
         m_amounts[IMMATURE_CREDIT].Reset();
         m_amounts[AVAILABLE_CREDIT].Reset();
         fChangeCached = false;
     }
 
     void BindWallet(CWallet *pwalletIn) {
         pwallet = pwalletIn;
         MarkDirty();
     }
 
     //! filter decides which addresses will count towards the debit
     Amount GetDebit(const isminefilter &filter) const;
     Amount GetCredit(interfaces::Chain::Lock &locked_chain,
                      const isminefilter &filter) const;
     Amount GetImmatureCredit(interfaces::Chain::Lock &locked_chain,
                              bool fUseCache = true) const;
     // TODO: Remove "NO_THREAD_SAFETY_ANALYSIS" and replace it with the correct
     // annotation "EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)". The
     // annotation "NO_THREAD_SAFETY_ANALYSIS" was temporarily added to avoid
     // having to resolve the issue of member access into incomplete type
     // CWallet.
     Amount GetAvailableCredit(interfaces::Chain::Lock &locked_chain,
                               bool fUseCache = true,
                               const isminefilter &filter = ISMINE_SPENDABLE)
         const NO_THREAD_SAFETY_ANALYSIS;
     Amount GetImmatureWatchOnlyCredit(interfaces::Chain::Lock &locked_chain,
                                       const bool fUseCache = true) const;
     Amount GetChange() const;
 
     // Get the marginal bytes if spending the specified output from this
     // transaction
     int GetSpendSize(unsigned int out, bool use_max_sig = false) const {
         return CalculateMaximumSignedInputSize(tx->vout[out], pwallet,
                                                use_max_sig);
     }
 
     void GetAmounts(std::list<COutputEntry> &listReceived,
                     std::list<COutputEntry> &listSent, Amount &nFee,
                     const isminefilter &filter) const;
 
     bool IsFromMe(const isminefilter &filter) const {
         return GetDebit(filter) > Amount::zero();
     }
 
     // True if only scriptSigs are different
     bool IsEquivalentTo(const CWalletTx &tx) const;
 
     bool InMempool() const;
     bool IsTrusted(interfaces::Chain::Lock &locked_chain) const;
 
     int64_t GetTxTime() const;
 
     // Pass this transaction to node for mempool insertion and relay to peers if
     // flag set to true
     bool SubmitMemoryPoolAndRelay(std::string &err_string, bool relay,
                                   interfaces::Chain::Lock &locked_chain);
 
     // TODO: Remove "NO_THREAD_SAFETY_ANALYSIS" and replace it with the correct
     // annotation "EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)". The annotation
     // "NO_THREAD_SAFETY_ANALYSIS" was temporarily added to avoid having to
     // resolve the issue of member access into incomplete type CWallet. Note
     // that we still have the runtime check "AssertLockHeld(pwallet->cs_wallet)"
     // in place.
     std::set<TxId> GetConflicts() const NO_THREAD_SAFETY_ANALYSIS;
 
     void SetConf(Status status, const BlockHash &block_hash, int posInBlock);
 
     /**
      * Return depth of transaction in blockchain:
      * <0  : conflicts with a transaction this deep in the blockchain
      *  0  : in memory pool, waiting to be included in a block
      * >=1 : this many blocks deep in the main chain
      */
     int GetDepthInMainChain(interfaces::Chain::Lock &locked_chain) const;
     bool IsInMainChain(interfaces::Chain::Lock &locked_chain) const {
         return GetDepthInMainChain(locked_chain) > 0;
     }
 
     /**
      * @return number of blocks to maturity for this transaction:
      *  0 : is not a coinbase transaction, or is a mature coinbase transaction
      * >0 : is a coinbase transaction which matures in this many blocks
      */
     int GetBlocksToMaturity(interfaces::Chain::Lock &locked_chain) const;
     bool isAbandoned() const {
         return m_confirm.status == CWalletTx::ABANDONED;
     }
     void setAbandoned() {
         m_confirm.status = CWalletTx::ABANDONED;
         m_confirm.hashBlock = BlockHash();
         m_confirm.nIndex = 0;
     }
     bool isConflicted() const {
         return m_confirm.status == CWalletTx::CONFLICTED;
     }
     void setConflicted() { m_confirm.status = CWalletTx::CONFLICTED; }
     bool isUnconfirmed() const {
         return m_confirm.status == CWalletTx::UNCONFIRMED;
     }
     void setUnconfirmed() { m_confirm.status = CWalletTx::UNCONFIRMED; }
     void setConfirmed() { m_confirm.status = CWalletTx::CONFIRMED; }
     TxId GetId() const { return tx->GetId(); }
     bool IsCoinBase() const { return tx->IsCoinBase(); }
     bool IsImmatureCoinBase(interfaces::Chain::Lock &locked_chain) const;
 };
 
 class COutput {
 public:
     const CWalletTx *tx;
     int i;
     int nDepth;
 
     /**
      * Pre-computed estimated size of this output as a fully-signed input in a
      * transaction. Can be -1 if it could not be calculated.
      */
     int nInputBytes;
 
     /** Whether we have the private keys to spend this output */
     bool fSpendable;
 
     /** Whether we know how to spend this output, ignoring the lack of keys */
     bool fSolvable;
 
     /**
      * Whether to use the maximum sized, 72 byte signature when calculating the
      * size of the input spend. This should only be set when watch-only outputs
      * are allowed.
      */
     bool use_max_sig;
 
     /**
      * Whether this output is considered safe to spend. Unconfirmed transactions
      * from outside keys are considered unsafe and will not be used to fund new
      * spending transactions.
      */
     bool fSafe;
 
     COutput(const CWalletTx *txIn, int iIn, int nDepthIn, bool fSpendableIn,
             bool fSolvableIn, bool fSafeIn, bool use_max_sig_in = false) {
         tx = txIn;
         i = iIn;
         nDepth = nDepthIn;
         fSpendable = fSpendableIn;
         fSolvable = fSolvableIn;
         fSafe = fSafeIn;
         nInputBytes = -1;
         use_max_sig = use_max_sig_in;
         // If known and signable by the given wallet, compute nInputBytes
         // Failure will keep this value -1
         if (fSpendable && tx) {
             nInputBytes = tx->GetSpendSize(i, use_max_sig);
         }
     }
 
     std::string ToString() const;
 
     inline CInputCoin GetInputCoin() const {
         return CInputCoin(tx->tx, i, nInputBytes);
     }
 };
 
 struct CoinSelectionParams {
     bool use_bnb = true;
     size_t change_output_size = 0;
     size_t change_spend_size = 0;
     CFeeRate effective_fee = CFeeRate(Amount::zero());
     size_t tx_noinputs_size = 0;
 
     CoinSelectionParams(bool use_bnb_, size_t change_output_size_,
                         size_t change_spend_size_, CFeeRate effective_fee_,
                         size_t tx_noinputs_size_)
         : use_bnb(use_bnb_), change_output_size(change_output_size_),
           change_spend_size(change_spend_size_), effective_fee(effective_fee_),
           tx_noinputs_size(tx_noinputs_size_) {}
     CoinSelectionParams() {}
 };
 
 // forward declarations for ScanForWalletTransactions/RescanFromTime
 class WalletRescanReserver;
 
 /**
  * A CWallet maintains a set of transactions and balances, and provides the
  * ability to create new transactions.
  */
 class CWallet final : public WalletStorage,
                       public interfaces::Chain::Notifications {
 private:
     CKeyingMaterial vMasterKey GUARDED_BY(cs_KeyStore);
 
     //! if fUseCrypto is true, mapKeys must be empty
     //! if fUseCrypto is false, vMasterKey must be empty
     std::atomic<bool> fUseCrypto;
 
     //! keeps track of whether Unlock has run a thorough check before
     bool fDecryptionThoroughlyChecked;
 
     bool SetCrypted();
     bool Unlock(const CKeyingMaterial &vMasterKeyIn,
                 bool accept_no_keys = false);
 
     std::atomic<bool> fAbortRescan{false};
     // controlled by WalletRescanReserver
     std::atomic<bool> fScanningWallet{false};
     std::atomic<int64_t> m_scanning_start{0};
     std::atomic<double> m_scanning_progress{0};
     std::mutex mutexScanning;
     friend class WalletRescanReserver;
 
     //! the current wallet version: clients below this version are not able to
     //! load the wallet
     int nWalletVersion GUARDED_BY(cs_wallet) = FEATURE_BASE;
 
     //! the maximum wallet format version: memory-only variable that specifies
     //! to what version this wallet may be upgraded
     int nWalletMaxVersion GUARDED_BY(cs_wallet) = FEATURE_BASE;
 
     int64_t nNextResend = 0;
     int64_t nLastResend = 0;
     bool fBroadcastTransactions = false;
     // Local time that the tip block was received. Used to schedule wallet
     // rebroadcasts.
     std::atomic<int64_t> m_best_block_time{0};
 
     /**
      * Used to keep track of spent outpoints, and detect and report conflicts
      * (double-spends or mutated transactions where the mutant gets mined).
      */
     typedef std::multimap<COutPoint, TxId> TxSpends;
     TxSpends mapTxSpends GUARDED_BY(cs_wallet);
     void AddToSpends(const COutPoint &outpoint, const TxId &wtxid)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void AddToSpends(const TxId &wtxid) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Add a transaction to the wallet, or update it. pIndex and posInBlock
      * should be set when the transaction was known to be included in a
      * block. When *pIndex == nullptr, then wallet state is not updated in
      * AddToWallet, but notifications happen and cached balances are marked
      * dirty.
      *
      * If fUpdate is true, existing transactions will be updated.
      * TODO: One exception to this is that the abandoned state is cleared under
      * the assumption that any further notification of a transaction that was
      * considered abandoned is an indication that it is not safe to be
      * considered abandoned. Abandoned state should probably be more carefully
      * tracked via different posInBlock signals or by checking mempool presence
      * when necessary.
      */
     bool AddToWalletIfInvolvingMe(const CTransactionRef &tx,
                                   CWalletTx::Status status,
                                   const BlockHash &block_hash, int posInBlock,
                                   bool fUpdate)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Mark a transaction (and its in-wallet descendants) as conflicting with a
      * particular block.
      */
     void MarkConflicted(const BlockHash &hashBlock, const TxId &txid);
 
     /**
      * Mark a transaction's inputs dirty, thus forcing the outputs to be
      * recomputed
      */
     void MarkInputsDirty(const CTransactionRef &tx)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     void SyncMetaData(std::pair<TxSpends::iterator, TxSpends::iterator>)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Used by
      * TransactionAddedToMemorypool/BlockConnected/Disconnected/ScanForWalletTransactions.
      * Should be called with non-zero block_hash and posInBlock if this is for a
      * transaction that is included in a block.
      */
     void SyncTransaction(const CTransactionRef &tx, CWalletTx::Status status,
                          const BlockHash &block_hash, int posInBlock = 0,
                          bool update_tx = true)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     std::atomic<uint64_t> m_wallet_flags{0};
 
     bool SetAddressBookWithDB(WalletBatch &batch, const CTxDestination &address,
                               const std::string &strName,
                               const std::string &strPurpose);
 
     //! Unsets a wallet flag and saves it to disk
     void UnsetWalletFlagWithDB(WalletBatch &batch, uint64_t flag);
 
     //! Unset the blank wallet flag and saves it to disk
     void UnsetBlankWalletFlag(WalletBatch &batch) override;
 
     /** Interface for accessing chain state. */
     interfaces::Chain *m_chain;
 
     /**
      * Wallet location which includes wallet name (see WalletLocation).
      */
     WalletLocation m_location;
 
     /** Internal database handle. */
     std::unique_ptr<WalletDatabase> database;
 
     /**
      * The following is used to keep track of how far behind the wallet is
      * from the chain sync, and to allow clients to block on us being caught up.
      *
-     * Note that this is *not* how far we've processed, we may need some rescan
-     * to have seen all transactions in the chain, but is only used to track
-     * live BlockConnected callbacks.
+     * Processed hash is a pointer on node's tip and doesn't imply that the
+     * wallet has scanned sequentially all blocks up to this one.
      */
     BlockHash m_last_block_processed GUARDED_BY(cs_wallet);
 
+    /* Height of last block processed is used by wallet to know depth of
+     * transactions without relying on Chain interface beyond asynchronous
+     * updates. For safety, we initialize it to -1. Height is a pointer on
+     * node's tip and doesn't imply that the wallet has scanned sequentially all
+     * blocks up to this one.
+     */
+    int m_last_block_processed_height GUARDED_BY(cs_wallet) = -1;
+
 public:
     const CChainParams &chainParams;
     /*
      * Main wallet lock.
      * This lock protects all the fields added by CWallet.
      */
     mutable RecursiveMutex cs_wallet;
 
     /**
      * Get database handle used by this wallet. Ideally this function would not
      * be necessary.
      */
     WalletDatabase &GetDBHandle() { return *database; }
     WalletDatabase &GetDatabase() override { return *database; }
 
     /**
      * Select a set of coins such that nValueRet >= nTargetValue and at least
      * all coins from coinControl are selected; Never select unconfirmed coins
      * if they are not ours.
      */
     bool SelectCoins(const std::vector<COutput> &vAvailableCoins,
                      const Amount nTargetValue,
                      std::set<CInputCoin> &setCoinsRet, Amount &nValueRet,
                      const CCoinControl &coin_control,
                      CoinSelectionParams &coin_selection_params,
                      bool &bnb_used) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     const WalletLocation &GetLocation() const { return m_location; }
 
     /**
      * Get a name for this wallet for logging/debugging purposes.
      */
     const std::string &GetName() const { return m_location.GetName(); }
 
     typedef std::map<unsigned int, CMasterKey> MasterKeyMap;
     MasterKeyMap mapMasterKeys;
     unsigned int nMasterKeyMaxID = 0;
 
     /** Construct wallet with specified name and database implementation. */
     CWallet(const CChainParams &chainParamsIn, interfaces::Chain *chain,
             const WalletLocation &location,
             std::unique_ptr<WalletDatabase> databaseIn)
         : fUseCrypto(false), fDecryptionThoroughlyChecked(false),
           m_chain(chain), m_location(location), database(std::move(databaseIn)),
           chainParams(chainParamsIn) {}
 
     ~CWallet() {
         // Should not have slots connected at this point.
         assert(NotifyUnload.empty());
         delete encrypted_batch;
         encrypted_batch = nullptr;
     }
 
     bool IsCrypted() const { return fUseCrypto; }
     bool IsLocked() const override;
     bool Lock();
 
     /** Interface to assert chain access and if successful lock it */
     std::unique_ptr<interfaces::Chain::Lock> LockChain() {
         return m_chain ? m_chain->lock() : nullptr;
     }
 
     std::map<TxId, CWalletTx> mapWallet GUARDED_BY(cs_wallet);
 
     typedef std::multimap<int64_t, CWalletTx *> TxItems;
     TxItems wtxOrdered;
 
     int64_t nOrderPosNext GUARDED_BY(cs_wallet) = 0;
     uint64_t nAccountingEntryNumber = 0;
 
     std::map<CTxDestination, CAddressBookData>
         mapAddressBook GUARDED_BY(cs_wallet);
 
     std::set<COutPoint> setLockedCoins GUARDED_BY(cs_wallet);
 
     /** Registered interfaces::Chain::Notifications handler. */
     std::unique_ptr<interfaces::Handler> m_chain_notifications_handler;
 
     /** Interface for accessing chain state. */
     interfaces::Chain &chain() const {
         assert(m_chain);
         return *m_chain;
     }
 
     const CWalletTx *GetWalletTx(const TxId &txid) const;
 
     //! check whether we are allowed to upgrade (or already support) to the
     //! named feature
     bool CanSupportFeature(enum WalletFeature wf) const override
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet) {
         AssertLockHeld(cs_wallet);
         return nWalletMaxVersion >= wf;
     }
 
     /**
      * populate vCoins with vector of available COutputs.
      */
     void AvailableCoins(interfaces::Chain::Lock &locked_chain,
                         std::vector<COutput> &vCoins, bool fOnlySafe = true,
                         const CCoinControl *coinControl = nullptr,
                         const Amount nMinimumAmount = SATOSHI,
                         const Amount nMaximumAmount = MAX_MONEY,
                         const Amount nMinimumSumAmount = MAX_MONEY,
                         const uint64_t nMaximumCount = 0) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Return list of available coins and locked coins grouped by non-change
      * output address.
      */
     std::map<CTxDestination, std::vector<COutput>>
     ListCoins(interfaces::Chain::Lock &locked_chain) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Find non-change parent output.
      */
     const CTxOut &FindNonChangeParentOutput(const CTransaction &tx,
                                             int output) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Shuffle and select coins until nTargetValue is reached while avoiding
      * small change; This method is stochastic for some inputs and upon
      * completion the coin set and corresponding actual target value is
      * assembled.
      */
     bool SelectCoinsMinConf(const Amount nTargetValue,
                             const CoinEligibilityFilter &eligibility_filter,
                             std::vector<OutputGroup> groups,
                             std::set<CInputCoin> &setCoinsRet,
                             Amount &nValueRet,
                             const CoinSelectionParams &coin_selection_params,
                             bool &bnb_used) const;
 
     bool IsSpent(interfaces::Chain::Lock &locked_chain,
                  const COutPoint &outpoint) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     // Whether this or any UTXO with the same CTxDestination has been spent.
     bool IsUsedDestination(const CTxDestination &dst) const;
     bool IsUsedDestination(const TxId &txid, unsigned int n) const;
     void SetUsedDestinationState(const TxId &hash, unsigned int n, bool used);
 
     std::vector<OutputGroup> GroupOutputs(const std::vector<COutput> &outputs,
                                           bool single_coin) const;
 
     bool IsLockedCoin(const COutPoint &outpoint) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void LockCoin(const COutPoint &output) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void UnlockCoin(const COutPoint &output)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void UnlockAllCoins() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void ListLockedCoins(std::vector<COutPoint> &vOutpts) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /*
      * Rescan abort properties
      */
     void AbortRescan() { fAbortRescan = true; }
     bool IsAbortingRescan() { return fAbortRescan; }
     bool IsScanning() { return fScanningWallet; }
     int64_t ScanningDuration() const {
         return fScanningWallet ? GetTimeMillis() - m_scanning_start : 0;
     }
     double ScanningProgress() const {
         return fScanningWallet ? double(m_scanning_progress) : 0;
     }
 
     //! Upgrade stored CKeyMetadata objects to store key origin info as
     //! KeyOriginInfo
     void UpgradeKeyMetadata() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     bool LoadMinVersion(int nVersion) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet) {
         AssertLockHeld(cs_wallet);
         nWalletVersion = nVersion;
         nWalletMaxVersion = std::max(nWalletMaxVersion, nVersion);
         return true;
     }
 
     //! Adds a destination data tuple to the store, and saves it to disk
     bool AddDestData(const CTxDestination &dest, const std::string &key,
                      const std::string &value)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Erases a destination data tuple in the store and on disk
     bool EraseDestData(const CTxDestination &dest, const std::string &key)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Adds a destination data tuple to the store, without saving it to disk
     void LoadDestData(const CTxDestination &dest, const std::string &key,
                       const std::string &value)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Look up a destination data tuple in the store, return true if found
     //! false otherwise
     bool GetDestData(const CTxDestination &dest, const std::string &key,
                      std::string *value) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Get all destination values matching a prefix.
     std::vector<std::string> GetDestValues(const std::string &prefix) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     //! Holds a timestamp at which point the wallet is scheduled (externally) to
     //! be relocked. Caller must arrange for actual relocking to occur via
     //! Lock().
     int64_t nRelockTime = 0;
 
     bool Unlock(const SecureString &strWalletPassphrase,
                 bool accept_no_keys = false);
     bool ChangeWalletPassphrase(const SecureString &strOldWalletPassphrase,
                                 const SecureString &strNewWalletPassphrase);
     bool EncryptWallet(const SecureString &strWalletPassphrase);
 
     void GetKeyBirthTimes(interfaces::Chain::Lock &locked_chain,
                           std::map<CKeyID, int64_t> &mapKeyBirth) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     unsigned int ComputeTimeSmart(const CWalletTx &wtx) const;
 
     /**
      * Increment the next transaction order id
      * @return next transaction order id
      */
     int64_t IncOrderPosNext(WalletBatch *batch = nullptr)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     DBErrors ReorderTransactions();
 
     void MarkDirty();
     bool AddToWallet(const CWalletTx &wtxIn, bool fFlushOnClose = true);
     void LoadToWallet(CWalletTx &wtxIn) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void TransactionAddedToMempool(const CTransactionRef &tx) override;
     void BlockConnected(const CBlock &block,
                         const std::vector<CTransactionRef> &vtxConflicted,
                         int height) override;
     void BlockDisconnected(const CBlock &block, int height) override;
     void UpdatedBlockTip() override;
     int64_t RescanFromTime(int64_t startTime,
                            const WalletRescanReserver &reserver, bool update);
 
     struct ScanResult {
         enum { SUCCESS, FAILURE, USER_ABORT } status = SUCCESS;
 
         //! Hash and height of most recent block that was successfully scanned.
         //! Unset if no blocks were scanned due to read errors or the chain
         //! being empty.
         BlockHash last_scanned_block;
         Optional<int> last_scanned_height;
 
         //! Hash of the most recent block that could not be scanned due to
         //! read errors or pruning. Will be set if status is FAILURE, unset if
         //! status is SUCCESS, and may or may not be set if status is
         //! USER_ABORT.
         BlockHash last_failed_block;
     };
     ScanResult ScanForWalletTransactions(const BlockHash &first_block,
                                          const BlockHash &last_block,
                                          const WalletRescanReserver &reserver,
                                          bool fUpdate);
     void TransactionRemovedFromMempool(const CTransactionRef &ptx) override;
     void ReacceptWalletTransactions(interfaces::Chain::Lock &locked_chain)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void ResendWalletTransactions();
     struct Balance {
         //! Trusted, at depth=GetBalance.min_depth or more
         Amount m_mine_trusted{Amount::zero()};
         //! Untrusted, but in mempool (pending)
         Amount m_mine_untrusted_pending{Amount::zero()};
         //! Immature coinbases in the main chain
         Amount m_mine_immature{Amount::zero()};
         Amount m_watchonly_trusted{Amount::zero()};
         Amount m_watchonly_untrusted_pending{Amount::zero()};
         Amount m_watchonly_immature{Amount::zero()};
     };
     Balance GetBalance(int min_depth = 0, bool avoid_reuse = true) const;
     Amount GetAvailableBalance(const CCoinControl *coinControl = nullptr) const;
 
     OutputType TransactionChangeType(OutputType change_type,
                                      const std::vector<CRecipient> &vecSend);
 
     /**
      * Insert additional inputs into the transaction by calling
      * CreateTransaction();
      */
     bool FundTransaction(CMutableTransaction &tx, Amount &nFeeRet,
                          int &nChangePosInOut, std::string &strFailReason,
                          bool lockUnspents,
                          const std::set<int> &setSubtractFeeFromOutputs,
                          CCoinControl coinControl);
     bool SignTransaction(CMutableTransaction &tx)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /**
      * Create a new transaction paying the recipients with a set of coins
      * selected by SelectCoins(); Also create the change output, when needed
      * @note passing nChangePosInOut as -1 will result in setting a random
      * position
      */
     bool CreateTransaction(interfaces::Chain::Lock &locked_chain,
                            const std::vector<CRecipient> &vecSend,
                            CTransactionRef &tx, Amount &nFeeRet,
                            int &nChangePosInOut, std::string &strFailReason,
                            const CCoinControl &coin_control, bool sign = true);
     /**
      * Submit the transaction to the node's mempool and then relay to peers.
      * Should be called after CreateTransaction unless you want to abort
      * broadcasting the transaction.
      *
      * @param tx[in] The transaction to be broadcast.
      * @param mapValue[in] key-values to be set on the transaction.
      * @param orderForm[in] BIP 70 / BIP 21 order form details to be set on the
      * transaction.
      */
     void CommitTransaction(
         CTransactionRef tx, mapValue_t mapValue,
         std::vector<std::pair<std::string, std::string>> orderForm);
 
     bool DummySignTx(CMutableTransaction &txNew, const std::set<CTxOut> &txouts,
                      bool use_max_sig = false) const {
         std::vector<CTxOut> v_txouts(txouts.size());
         std::copy(txouts.begin(), txouts.end(), v_txouts.begin());
         return DummySignTx(txNew, v_txouts, use_max_sig);
     }
     bool DummySignTx(CMutableTransaction &txNew,
                      const std::vector<CTxOut> &txouts,
                      bool use_max_sig = false) const;
     bool DummySignInput(CTxIn &tx_in, const CTxOut &txout,
                         bool use_max_sig = false) const;
 
     bool ImportScripts(const std::set<CScript> scripts, int64_t timestamp)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool ImportPrivKeys(const std::map<CKeyID, CKey> &privkey_map,
                         const int64_t timestamp)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool ImportPubKeys(
         const std::vector<CKeyID> &ordered_pubkeys,
         const std::map<CKeyID, CPubKey> &pubkey_map,
         const std::map<CKeyID, std::pair<CPubKey, KeyOriginInfo>> &key_origins,
         const bool add_keypool, const bool internal, const int64_t timestamp)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool ImportScriptPubKeys(const std::string &label,
                              const std::set<CScript> &script_pub_keys,
                              const bool have_solving_data,
                              const bool apply_label, const int64_t timestamp)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     CFeeRate m_pay_tx_fee{DEFAULT_PAY_TX_FEE};
     bool m_spend_zero_conf_change{DEFAULT_SPEND_ZEROCONF_CHANGE};
     //! will be false if -fallbackfee=0
     bool m_allow_fallback_fee{true};
     // Override with -mintxfee
     CFeeRate m_min_fee{DEFAULT_TRANSACTION_MINFEE_PER_KB};
     /**
      * If fee estimation does not have enough data to provide estimates, use
      * this fee instead. Has no effect if not using fee estimation Override with
      * -fallbackfee
      */
     CFeeRate m_fallback_fee{DEFAULT_FALLBACK_FEE};
     OutputType m_default_address_type{DEFAULT_ADDRESS_TYPE};
     OutputType m_default_change_type{DEFAULT_CHANGE_TYPE};
     /**
      * Absolute maximum transaction fee (in satoshis) used by default for the
      * wallet.
      */
     Amount m_default_max_tx_fee{DEFAULT_TRANSACTION_MAXFEE};
 
     size_t KeypoolCountExternalKeys() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool TopUpKeyPool(unsigned int kpSize = 0);
 
     int64_t GetOldestKeyPoolTime();
 
     std::set<std::set<CTxDestination>> GetAddressGroupings()
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     std::map<CTxDestination, Amount>
     GetAddressBalances(interfaces::Chain::Lock &locked_chain);
 
     std::set<CTxDestination> GetLabelAddresses(const std::string &label) const;
 
     bool GetNewDestination(const OutputType type, const std::string label,
                            CTxDestination &dest, std::string &error);
     bool GetNewChangeDestination(const OutputType type, CTxDestination &dest,
                                  std::string &error);
 
     isminetype IsMine(const CTxDestination &dest) const;
     isminetype IsMine(const CScript &script) const;
     isminetype IsMine(const CTxIn &txin) const;
     /**
      * Returns amount of debit if the input matches the filter, otherwise
      * returns 0
      */
     Amount GetDebit(const CTxIn &txin, const isminefilter &filter) const;
     isminetype IsMine(const CTxOut &txout) const;
     Amount GetCredit(const CTxOut &txout, const isminefilter &filter) const;
     bool IsChange(const CTxOut &txout) const;
     bool IsChange(const CScript &script) const;
     Amount GetChange(const CTxOut &txout) const;
     bool IsMine(const CTransaction &tx) const;
     /** should probably be renamed to IsRelevantToMe */
     bool IsFromMe(const CTransaction &tx) const;
     Amount GetDebit(const CTransaction &tx, const isminefilter &filter) const;
     /** Returns whether all of the inputs match the filter */
     bool IsAllFromMe(const CTransaction &tx, const isminefilter &filter) const;
     Amount GetCredit(const CTransaction &tx, const isminefilter &filter) const;
     Amount GetChange(const CTransaction &tx) const;
     void ChainStateFlushed(const CBlockLocator &loc) override;
 
     DBErrors LoadWallet(bool &fFirstRunRet);
     DBErrors ZapWalletTx(std::vector<CWalletTx> &vWtx);
     DBErrors ZapSelectTx(std::vector<TxId> &txIdsIn,
                          std::vector<TxId> &txIdsOut)
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     bool SetAddressBook(const CTxDestination &address,
                         const std::string &strName, const std::string &purpose);
 
     bool DelAddressBook(const CTxDestination &address);
 
     unsigned int GetKeyPoolSize() const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     //! signify that a particular wallet feature is now used. this may change
     //! nWalletVersion and nWalletMaxVersion if those are lower
     void SetMinVersion(enum WalletFeature, WalletBatch *batch_in = nullptr,
                        bool fExplicit = false) override;
 
     //! change which version we're allowed to upgrade to (note that this does
     //! not immediately imply upgrading to that format)
     bool SetMaxVersion(int nVersion);
 
     //! get the current wallet format (the oldest client version guaranteed to
     //! understand this wallet)
     int GetVersion() {
         LOCK(cs_wallet);
         return nWalletVersion;
     }
 
     //! Get wallet transactions that conflict with given transaction (spend same
     //! outputs)
     std::set<TxId> GetConflicts(const TxId &txid) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     //! Check if a given transaction has any of its outputs spent by another
     //! transaction in the wallet
     bool HasWalletSpend(const TxId &txid) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     //! Flush wallet (bitdb flush)
     void Flush(bool shutdown = false);
 
     /** Wallet is about to be unloaded */
     boost::signals2::signal<void()> NotifyUnload;
 
     /**
      * Address book entry changed.
      * @note called with lock cs_wallet held.
      */
     boost::signals2::signal<void(CWallet *wallet, const CTxDestination &address,
                                  const std::string &label, bool isMine,
                                  const std::string &purpose, ChangeType status)>
         NotifyAddressBookChanged;
 
     /**
      * Wallet transaction added, removed or updated.
      * @note called with lock cs_wallet held.
      */
     boost::signals2::signal<void(CWallet *wallet, const TxId &txid,
                                  ChangeType status)>
         NotifyTransactionChanged;
 
     /** Show progress e.g. for rescan */
     boost::signals2::signal<void(const std::string &title, int nProgress)>
         ShowProgress;
 
     /** Watch-only address added */
     boost::signals2::signal<void(bool fHaveWatchOnly)> NotifyWatchonlyChanged;
 
     /** Keypool has new keys */
     boost::signals2::signal<void()> NotifyCanGetAddressesChanged;
 
     /**
      * Wallet status (encrypted, locked) changed.
      * Note: Called without locks held.
      */
     boost::signals2::signal<void(CWallet *wallet)> NotifyStatusChanged;
 
     /** Inquire whether this wallet broadcasts transactions. */
     bool GetBroadcastTransactions() const { return fBroadcastTransactions; }
     /** Set whether this wallet broadcasts transactions. */
     void SetBroadcastTransactions(bool broadcast) {
         fBroadcastTransactions = broadcast;
     }
 
     /** Return whether transaction can be abandoned */
     bool TransactionCanBeAbandoned(const TxId &txid) const;
 
     /**
      * Mark a transaction (and it in-wallet descendants) as abandoned so its
      * inputs may be respent.
      */
     bool AbandonTransaction(interfaces::Chain::Lock &locked_chain,
                             const TxId &txid);
 
     //! Verify wallet naming and perform salvage on the wallet if required
     static bool Verify(const CChainParams &chainParams,
                        interfaces::Chain &chain, const WalletLocation &location,
                        bool salvage_wallet, std::string &error_string,
                        std::vector<std::string> &warnings);
 
     /**
      * Initializes the wallet, returns a new CWallet instance or a null pointer
      * in case of an error.
      */
     static std::shared_ptr<CWallet> CreateWalletFromFile(
         const CChainParams &chainParams, interfaces::Chain &chain,
         const WalletLocation &location, std::string &error,
         std::vector<std::string> &warnings, uint64_t wallet_creation_flags = 0);
 
     /**
      * Wallet post-init setup
      * Gives the wallet a chance to register repetitive tasks and complete
      * post-init tasks
      */
     void postInitProcess();
 
     bool BackupWallet(const std::string &strDest);
 
     /* Returns true if HD is enabled */
     bool IsHDEnabled() const;
 
     /**
      * Returns true if the wallet can give out new addresses. This means it has
      * keys in the keypool or can generate new keys.
      */
     bool CanGetAddresses(bool internal = false);
 
     /**
      * Blocks until the wallet state is up-to-date to /at least/ the current
      * chain at the time this function is entered.
      * Obviously holding cs_main/cs_wallet when going into this call may cause
      * deadlock
      */
     void BlockUntilSyncedToCurrentChain() LOCKS_EXCLUDED(cs_main, cs_wallet);
 
     /**
      * Set a single wallet flag.
      */
     void SetWalletFlag(uint64_t flags);
 
     /**
      * Unsets a single wallet flag.
      */
     void UnsetWalletFlag(uint64_t flag);
 
     /**
      * Check if a certain wallet flag is set.
      */
     bool IsWalletFlagSet(uint64_t flag) const override;
 
     /**
      * Overwrite all flags by the given uint64_t.
      * Returns false if unknown, non-tolerable flags are present.
      */
     bool SetWalletFlags(uint64_t overwriteFlags, bool memOnly);
 
     /**
      * Returns a bracketed wallet name for displaying in logs, will return
      * [default wallet] if the wallet has no name.
      */
     const std::string GetDisplayName() const override {
         std::string wallet_name =
             GetName().length() == 0 ? "default wallet" : GetName();
         return strprintf("[%s]", wallet_name);
     };
 
     /**
      * Prepends the wallet name in logging output to ease debugging in
      * multi-wallet use cases.
      */
     template <typename... Params>
     void WalletLogPrintf(std::string fmt, Params... parameters) const {
         LogPrintf(("%s " + fmt).c_str(), GetDisplayName(), parameters...);
     };
 
     template <typename... Params>
     void WalletLogPrintfToBeContinued(std::string fmt,
                                       Params... parameters) const {
         LogPrintfToBeContinued(("%s " + fmt).c_str(), GetDisplayName(),
                                parameters...);
     };
 
     ScriptPubKeyMan *GetScriptPubKeyMan() const;
     const SigningProvider *GetSigningProvider() const;
     LegacyScriptPubKeyMan *GetLegacyScriptPubKeyMan() const;
 
     // Temporary LegacyScriptPubKeyMan accessors and aliases.
     friend class LegacyScriptPubKeyMan;
     std::unique_ptr<LegacyScriptPubKeyMan> m_spk_man =
         std::make_unique<LegacyScriptPubKeyMan>(*this);
     RecursiveMutex &cs_KeyStore = m_spk_man->cs_KeyStore;
     LegacyScriptPubKeyMan::KeyMap &
         mapKeys GUARDED_BY(cs_KeyStore) = m_spk_man->mapKeys;
     LegacyScriptPubKeyMan::ScriptMap &
         mapScripts GUARDED_BY(cs_KeyStore) = m_spk_man->mapScripts;
     LegacyScriptPubKeyMan::CryptedKeyMap &
         mapCryptedKeys GUARDED_BY(cs_KeyStore) = m_spk_man->mapCryptedKeys;
     LegacyScriptPubKeyMan::WatchOnlySet &
         setWatchOnly GUARDED_BY(cs_KeyStore) = m_spk_man->setWatchOnly;
     LegacyScriptPubKeyMan::WatchKeyMap &
         mapWatchKeys GUARDED_BY(cs_KeyStore) = m_spk_man->mapWatchKeys;
     WalletBatch *&
         encrypted_batch GUARDED_BY(cs_wallet) = m_spk_man->encrypted_batch;
     using CryptedKeyMap = LegacyScriptPubKeyMan::CryptedKeyMap;
+
+    /** Get last block processed height */
+    int GetLastBlockHeight() const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet) {
+        AssertLockHeld(cs_wallet);
+        assert(m_last_block_processed_height >= 0);
+        return m_last_block_processed_height;
+    };
+    /** Set last block processed height, currently only use in unit test */
+    void SetLastBlockProcessed(int block_height, BlockHash block_hash)
+        EXCLUSIVE_LOCKS_REQUIRED(cs_wallet) {
+        AssertLockHeld(cs_wallet);
+        m_last_block_processed_height = block_height;
+        m_last_block_processed = block_hash;
+    };
 };
 
 /**
  * Called periodically by the schedule thread. Prompts individual wallets to
  * resend their transactions. Actual rebroadcast schedule is managed by the
  * wallets themselves.
  */
 void MaybeResendWalletTxs();
 
 /** RAII object to check and reserve a wallet rescan */
 class WalletRescanReserver {
 private:
     CWallet *m_wallet;
     bool m_could_reserve;
 
 public:
     explicit WalletRescanReserver(CWallet *w)
         : m_wallet(w), m_could_reserve(false) {}
 
     bool reserve() {
         assert(!m_could_reserve);
         std::lock_guard<std::mutex> lock(m_wallet->mutexScanning);
         if (m_wallet->fScanningWallet) {
             return false;
         }
         m_wallet->m_scanning_start = GetTimeMillis();
         m_wallet->m_scanning_progress = 0;
         m_wallet->fScanningWallet = true;
         m_could_reserve = true;
         return true;
     }
 
     bool isReserved() const {
         return (m_could_reserve && m_wallet->fScanningWallet);
     }
 
     ~WalletRescanReserver() {
         std::lock_guard<std::mutex> lock(m_wallet->mutexScanning);
         if (m_could_reserve) {
             m_wallet->fScanningWallet = false;
         }
     }
 };
 
 // Calculate the size of the transaction assuming all signatures are max size
 // Use DummySignatureCreator, which inserts 71 byte signatures everywhere.
 // NOTE: this requires that all inputs must be in mapWallet (eg the tx should
 // be IsAllFromMe).
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet,
                                      bool use_max_sig = false)
     EXCLUSIVE_LOCKS_REQUIRED(wallet->cs_wallet);
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
                                      const CWallet *wallet,
                                      const std::vector<CTxOut> &txouts,
                                      bool use_max_sig = false);
 
 #endif // BITCOIN_WALLET_WALLET_H