diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index b8eccbaae..a628615b9 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -1,1277 +1,1281 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Copyright (c) 2018 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 <script/ismine.h>
 #include <script/sign.h>
 #include <streams.h>
 #include <tinyformat.h>
 #include <ui_interface.h>
 #include <utilstrencodings.h>
 #include <validationinterface.h>
 #include <wallet/crypter.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/walletdb.h>
 
 #include <boost/thread.hpp>
 
 #include <algorithm>
 #include <atomic>
 #include <cstdint>
 #include <map>
 #include <set>
 #include <stdexcept>
 #include <string>
 #include <utility>
 #include <vector>
 
 typedef CWallet *CWalletRef;
 extern std::vector<CWalletRef> vpwallets;
 
 /**
  * Settings
  */
 extern CFeeRate payTxFee;
 extern bool bSpendZeroConfChange;
 
 static const unsigned int DEFAULT_KEYPOOL_SIZE = 1000;
 //! -paytxfee default
 static const Amount DEFAULT_TRANSACTION_FEE = Amount::zero();
 //! -fallbackfee default
 static const Amount DEFAULT_FALLBACK_FEE(20000 * SATOSHI);
 //! minimum recommended increment for BIP 125 replacement txs
 static const Amount WALLET_INCREMENTAL_RELAY_FEE(5000 * SATOSHI);
 //! target minimum change amount
 static const Amount MIN_CHANGE = CENT;
 //! final minimum change amount after paying for fees
 static const Amount MIN_FINAL_CHANGE = MIN_CHANGE / 2;
 //! Default for -spendzeroconfchange
 static const bool DEFAULT_SPEND_ZEROCONF_CHANGE = true;
 //! Default for -walletrejectlongchains
 static const bool DEFAULT_WALLET_REJECT_LONG_CHAINS = false;
 //! Largest (in bytes) free transaction we're willing to create
 static const unsigned int MAX_FREE_TRANSACTION_CREATE_SIZE = 1000;
 static const bool DEFAULT_WALLETBROADCAST = true;
 static const bool DEFAULT_DISABLE_WALLET = false;
 //! if set, all keys will be derived by using BIP32
 static const bool DEFAULT_USE_HD_WALLET = true;
 
 extern const char *DEFAULT_WALLET_DAT;
 
 static const int64_t TIMESTAMP_MIN = 0;
 
 class CBlockIndex;
 class CChainParams;
 class CCoinControl;
 class COutput;
 class CReserveKey;
 class CScript;
 class CScheduler;
 class CTxMemPool;
 class CWalletTx;
 
 /** (client) version numbers for particular wallet features */
 enum WalletFeature {
     // the earliest version new wallets supports (only useful for getinfo's
     // clientversion output)
     FEATURE_BASE = 10500,
 
     // wallet encryption
     FEATURE_WALLETCRYPT = 40000,
     // compressed public keys
     FEATURE_COMPRPUBKEY = 60000,
 
     // Hierarchical key derivation after BIP32 (HD Wallet)
     FEATURE_HD = 130000,
 
     // Wallet with HD chain split (change outputs will use m/0'/1'/k)
     FEATURE_HD_SPLIT = 160300,
 
     // HD is optional, use FEATURE_COMPRPUBKEY as latest version
     FEATURE_LATEST = FEATURE_COMPRPUBKEY,
 };
 
 /** A key pool entry */
 class CKeyPool {
 public:
     int64_t nTime;
     CPubKey vchPubKey;
     bool fInternal; // for change outputs
 
     CKeyPool();
     CKeyPool(const CPubKey &vchPubKeyIn, bool internalIn);
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         int nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) {
             READWRITE(nVersion);
         }
 
         READWRITE(nTime);
         READWRITE(vchPubKey);
         if (ser_action.ForRead()) {
             try {
                 READWRITE(fInternal);
             } catch (std::ios_base::failure &) {
                 /**
                  * flag as external address if we can't read the internal
                  * boolean
                  * (this will be the case for any wallet before the HD chain
                  * split version)
                  */
                 fInternal = false;
             }
         } else {
             READWRITE(fInternal);
         }
     }
 };
 
 /** Address book data */
 class CAddressBookData {
 public:
     std::string name;
     std::string purpose;
 
     CAddressBookData() : purpose("unknown") {}
 
     typedef std::map<std::string, std::string> StringMap;
     StringMap destdata;
 };
 
 struct CRecipient {
     CScript scriptPubKey;
     Amount nAmount;
     bool fSubtractFeeFromAmount;
 };
 
 typedef std::map<std::string, std::string> mapValue_t;
 
 static inline void ReadOrderPos(int64_t &nOrderPos, mapValue_t &mapValue) {
     if (!mapValue.count("n")) {
         // TODO: calculate elsewhere
         nOrderPos = -1;
         return;
     }
 
     nOrderPos = atoi64(mapValue["n"].c_str());
 }
 
 static inline void WriteOrderPos(const int64_t &nOrderPos,
                                  mapValue_t &mapValue) {
     if (nOrderPos == -1) return;
     mapValue["n"] = i64tostr(nOrderPos);
 }
 
 struct COutputEntry {
     CTxDestination destination;
     Amount amount;
     int vout;
 };
 
 /** A transaction with a merkle branch linking it to the block chain. */
 class CMerkleTx {
 private:
     /** Constant used in hashBlock to indicate tx has been abandoned */
     static const uint256 ABANDON_HASH;
 
 public:
     CTransactionRef tx;
     uint256 hashBlock;
 
     /**
      * An nIndex == -1 means that hashBlock (in nonzero) refers to the earliest
      * block in the chain we know this or any in-wallet dependency conflicts
      * with. Older clients interpret nIndex == -1 as unconfirmed for backward
      * compatibility.
      */
     int nIndex;
 
     CMerkleTx() {
         SetTx(MakeTransactionRef());
         Init();
     }
 
     explicit CMerkleTx(CTransactionRef arg) {
         SetTx(std::move(arg));
         Init();
     }
 
     void Init() {
         hashBlock = uint256();
         nIndex = -1;
     }
 
     void SetTx(CTransactionRef arg) { tx = std::move(arg); }
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         // For compatibility with older versions.
         std::vector<uint256> vMerkleBranch;
         READWRITE(tx);
         READWRITE(hashBlock);
         READWRITE(vMerkleBranch);
         READWRITE(nIndex);
     }
 
     void SetMerkleBranch(const CBlockIndex *pIndex, int posInBlock);
 
     /**
      * 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(const CBlockIndex *&pindexRet) const;
     int GetDepthInMainChain() const {
         const CBlockIndex *pindexRet;
         return GetDepthInMainChain(pindexRet);
     }
     bool IsInMainChain() const {
         const CBlockIndex *pindexRet;
         return GetDepthInMainChain(pindexRet) > 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() const;
     bool hashUnset() const {
         return (hashBlock.IsNull() || hashBlock == ABANDON_HASH);
     }
     bool isAbandoned() const { return (hashBlock == ABANDON_HASH); }
     void setAbandoned() { hashBlock = ABANDON_HASH; }
 
     TxId GetId() const { return tx->GetId(); }
     bool IsCoinBase() const { return tx->IsCoinBase(); }
     bool IsImmatureCoinBase() const;
 };
 
 /**
  * A transaction with a bunch of additional info that only the owner cares
  * about. It includes any unrecorded transactions needed to link it back to the
  * block chain.
  */
 class CWalletTx : public CMerkleTx {
 private:
     const CWallet *pwallet;
 
 public:
     mapValue_t mapValue;
     std::vector<std::pair<std::string, std::string>> vOrderForm;
     unsigned int fTimeReceivedIsTxTime;
     //!< time received by this node
     unsigned int nTimeReceived;
     /**
      * Stable timestamp that never changes, and reflects the order a transaction
      * was added to the wallet. Timestamp is based on the block time for a
      * transaction added as part of a block, or else the time when the
      * transaction was received if it wasn't part of a block, with the timestamp
      * adjusted in both cases so timestamp order matches the order transactions
      * were added to the wallet. More details can be found in
      * CWallet::ComputeTimeSmart().
      */
     unsigned int nTimeSmart;
     /**
      * From me flag is set to 1 for transactions that were created by the wallet
      * on this bitcoin node, and set to 0 for transactions that were created
      * externally and came in through the network or sendrawtransaction RPC.
      */
     char fFromMe;
     std::string strFromAccount;
     //!< position in ordered transaction list
     int64_t nOrderPos;
 
     // memory only
     mutable bool fDebitCached;
     mutable bool fCreditCached;
     mutable bool fImmatureCreditCached;
     mutable bool fAvailableCreditCached;
     mutable bool fWatchDebitCached;
     mutable bool fWatchCreditCached;
     mutable bool fImmatureWatchCreditCached;
     mutable bool fAvailableWatchCreditCached;
     mutable bool fChangeCached;
     mutable bool fInMempool;
     mutable Amount nDebitCached;
     mutable Amount nCreditCached;
     mutable Amount nImmatureCreditCached;
     mutable Amount nAvailableCreditCached;
     mutable Amount nWatchDebitCached;
     mutable Amount nWatchCreditCached;
     mutable Amount nImmatureWatchCreditCached;
     mutable Amount nAvailableWatchCreditCached;
     mutable Amount nChangeCached;
 
     CWalletTx(const CWallet *pwalletIn, CTransactionRef arg)
         : CMerkleTx(std::move(arg)) {
         Init(pwalletIn);
     }
 
     void Init(const CWallet *pwalletIn) {
         pwallet = pwalletIn;
         mapValue.clear();
         vOrderForm.clear();
         fTimeReceivedIsTxTime = false;
         nTimeReceived = 0;
         nTimeSmart = 0;
         fFromMe = false;
         strFromAccount.clear();
         fDebitCached = false;
         fCreditCached = false;
         fImmatureCreditCached = false;
         fAvailableCreditCached = false;
         fWatchDebitCached = false;
         fWatchCreditCached = false;
         fImmatureWatchCreditCached = false;
         fAvailableWatchCreditCached = false;
         fChangeCached = false;
         fInMempool = false;
         nDebitCached = Amount::zero();
         nCreditCached = Amount::zero();
         nImmatureCreditCached = Amount::zero();
         nAvailableCreditCached = Amount::zero();
         nWatchDebitCached = Amount::zero();
         nWatchCreditCached = Amount::zero();
         nAvailableWatchCreditCached = Amount::zero();
         nImmatureWatchCreditCached = Amount::zero();
         nChangeCached = Amount::zero();
         nOrderPos = -1;
     }
 
     template <typename Stream> void Serialize(Stream &s) const {
         char fSpent = false;
         mapValue_t mapValueCopy = mapValue;
 
         mapValueCopy["fromaccount"] = strFromAccount;
         WriteOrderPos(nOrderPos, mapValueCopy);
         if (nTimeSmart) {
             mapValueCopy["timesmart"] = strprintf("%u", nTimeSmart);
         }
 
         s << *static_cast<const CMerkleTx *>(this);
         //!< Used to be vtxPrev
         std::vector<CMerkleTx> vUnused;
         s << vUnused << mapValueCopy << vOrderForm << fTimeReceivedIsTxTime
           << nTimeReceived << fFromMe << fSpent;
     }
 
     template <typename Stream> void Unserialize(Stream &s) {
         Init(nullptr);
         char fSpent;
 
         s >> *static_cast<CMerkleTx *>(this);
         //!< Used to be vtxPrev
         std::vector<CMerkleTx> vUnused;
         s >> vUnused >> mapValue >> vOrderForm >> fTimeReceivedIsTxTime >>
             nTimeReceived >> fFromMe >> fSpent;
 
         strFromAccount = std::move(mapValue["fromaccount"]);
         ReadOrderPos(nOrderPos, mapValue);
         nTimeSmart = mapValue.count("timesmart")
                          ? (unsigned int)atoi64(mapValue["timesmart"])
                          : 0;
 
         mapValue.erase("fromaccount");
         mapValue.erase("version");
         mapValue.erase("spent");
         mapValue.erase("n");
         mapValue.erase("timesmart");
     }
 
     //! make sure balances are recalculated
     void MarkDirty() {
         fCreditCached = false;
         fAvailableCreditCached = false;
         fImmatureCreditCached = false;
         fWatchDebitCached = false;
         fWatchCreditCached = false;
         fAvailableWatchCreditCached = false;
         fImmatureWatchCreditCached = false;
         fDebitCached = false;
         fChangeCached = false;
     }
 
     void BindWallet(CWallet *pwalletIn) {
         pwallet = pwalletIn;
         MarkDirty();
     }
 
     //! filter decides which addresses will count towards the debit
     Amount GetDebit(const isminefilter &filter) const;
     Amount GetCredit(const isminefilter &filter) const;
     Amount GetImmatureCredit(bool fUseCache = true) const;
     Amount GetAvailableCredit(bool fUseCache = true) const;
     Amount GetImmatureWatchOnlyCredit(const bool fUseCache = true) const;
     Amount GetAvailableWatchOnlyCredit(const bool fUseCache = true) const;
     Amount GetChange() const;
 
     void GetAmounts(std::list<COutputEntry> &listReceived,
                     std::list<COutputEntry> &listSent, Amount &nFee,
                     std::string &strSentAccount,
                     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() const;
 
     int64_t GetTxTime() const;
     int GetRequestCount() const;
 
     // RelayWalletTransaction may only be called if fBroadcastTransactions!
     bool RelayWalletTransaction(CConnman *connman);
 
     /**
      * Pass this transaction to the mempool. Fails if absolute fee exceeds
      * absurd fee.
      */
     bool AcceptToMemoryPool(const Amount nAbsurdFee, CValidationState &state);
 
     std::set<TxId> GetConflicts() const;
 };
 
 class CInputCoin {
 public:
     CInputCoin(const CWalletTx *walletTx, unsigned int i) : wtx(walletTx) {
         if (!walletTx) {
             throw std::invalid_argument("walletTx should not be null");
         }
         if (i >= walletTx->tx->vout.size()) {
             throw std::out_of_range("The output index is out of range");
         }
 
         outpoint = COutPoint(walletTx->GetId(), i);
         txout = walletTx->tx->vout[i];
     }
 
     COutPoint outpoint;
     CTxOut txout;
     const CWalletTx *wtx;
 
     bool operator<(const CInputCoin &rhs) const {
         return outpoint < rhs.outpoint;
     }
 
     bool operator!=(const CInputCoin &rhs) const {
         return outpoint != rhs.outpoint;
     }
 
     bool operator==(const CInputCoin &rhs) const {
         return outpoint == rhs.outpoint;
     }
 };
 
 class COutput {
 public:
     const CWalletTx *tx;
     int i;
     int nDepth;
 
     /** 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 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) {
         tx = txIn;
         i = iIn;
         nDepth = nDepthIn;
         fSpendable = fSpendableIn;
         fSolvable = fSolvableIn;
         fSafe = fSafeIn;
     }
 
     std::string ToString() const;
 };
 
 /** Private key that includes an expiration date in case it never gets used. */
 class CWalletKey {
 public:
     CPrivKey vchPrivKey;
     int64_t nTimeCreated;
     int64_t nTimeExpires;
     std::string strComment;
     //! todo: add something to note what created it (user, getnewaddress,
     //! change) maybe should have a map<string, string> property map
 
     explicit CWalletKey(int64_t nExpires = 0);
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         int nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) READWRITE(nVersion);
         READWRITE(vchPrivKey);
         READWRITE(nTimeCreated);
         READWRITE(nTimeExpires);
         READWRITE(LIMITED_STRING(strComment, 65536));
     }
 };
 
 /**
  * Internal transfers.
  * Database key is acentry<account><counter>.
  */
 class CAccountingEntry {
 public:
     std::string strAccount;
     Amount nCreditDebit;
     int64_t nTime;
     std::string strOtherAccount;
     std::string strComment;
     mapValue_t mapValue;
     //!< position in ordered transaction list
     int64_t nOrderPos;
     uint64_t nEntryNo;
 
     CAccountingEntry() { SetNull(); }
 
     void SetNull() {
         nCreditDebit = Amount::zero();
         nTime = 0;
         strAccount.clear();
         strOtherAccount.clear();
         strComment.clear();
         nOrderPos = -1;
         nEntryNo = 0;
     }
 
     template <typename Stream> void Serialize(Stream &s) const {
         int nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) {
             s << nVersion;
         }
         //! Note: strAccount is serialized as part of the key, not here.
         s << nCreditDebit << nTime << strOtherAccount;
 
         mapValue_t mapValueCopy = mapValue;
         WriteOrderPos(nOrderPos, mapValueCopy);
 
         std::string strCommentCopy = strComment;
         if (!mapValueCopy.empty() || !_ssExtra.empty()) {
             CDataStream ss(s.GetType(), s.GetVersion());
             ss.insert(ss.begin(), '\0');
             ss << mapValueCopy;
             ss.insert(ss.end(), _ssExtra.begin(), _ssExtra.end());
             strCommentCopy.append(ss.str());
         }
         s << strCommentCopy;
     }
 
     template <typename Stream> void Unserialize(Stream &s) {
         int nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) {
             s >> nVersion;
         }
         //! Note: strAccount is serialized as part of the key, not here.
         s >> nCreditDebit >> nTime >> LIMITED_STRING(strOtherAccount, 65536) >>
             LIMITED_STRING(strComment, 65536);
 
         size_t nSepPos = strComment.find("\0", 0, 1);
         mapValue.clear();
         if (std::string::npos != nSepPos) {
             CDataStream ss(std::vector<char>(strComment.begin() + nSepPos + 1,
                                              strComment.end()),
                            s.GetType(), s.GetVersion());
             ss >> mapValue;
             _ssExtra = std::vector<char>(ss.begin(), ss.end());
         }
         ReadOrderPos(nOrderPos, mapValue);
         if (std::string::npos != nSepPos) {
             strComment.erase(nSepPos);
         }
 
         mapValue.erase("n");
     }
 
 private:
     std::vector<char> _ssExtra;
 };
 
 /**
  * A CWallet is an extension of a keystore, which also maintains a set of
  * transactions and balances, and provides the ability to create new
  * transactions.
  */
 class CWallet final : public CCryptoKeyStore, public CValidationInterface {
 private:
     static std::atomic<bool> fFlushScheduled;
     std::atomic<bool> fAbortRescan;
     std::atomic<bool> fScanningWallet;
 
     /**
      * 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 *coinControl = nullptr) const;
 
     CWalletDB *pwalletdbEncryption;
 
     //! the current wallet version: clients below this version are not able to
     //! load the wallet
     int nWalletVersion;
 
     //! the maximum wallet format version: memory-only variable that specifies
     //! to what version this wallet may be upgraded
     int nWalletMaxVersion;
 
     int64_t nNextResend;
     int64_t nLastResend;
     bool fBroadcastTransactions;
 
     /**
      * 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;
     void AddToSpends(const COutPoint &outpoint, const TxId &wtxid);
     void AddToSpends(const TxId &wtxid);
 
     /**
      * Mark a transaction (and its in-wallet descendants) as conflicting with a
      * particular block.
      */
     void MarkConflicted(const uint256 &hashBlock, const TxId &txid);
 
     void SyncMetaData(std::pair<TxSpends::iterator, TxSpends::iterator>);
 
     /**
      * Used by TransactionAddedToMemorypool/BlockConnected/Disconnected.
      * Should be called with pindexBlock and posInBlock if this is for a
      * transaction that is included in a block.
      */
     void SyncTransaction(const CTransactionRef &tx,
                          const CBlockIndex *pindex = nullptr,
                          int posInBlock = 0);
 
     /* the HD chain data model (external chain counters) */
     CHDChain hdChain;
 
     /* HD derive new child key (on internal or external chain) */
     void DeriveNewChildKey(CWalletDB &walletdb, CKeyMetadata &metadata,
                            CKey &secret, bool internal = false);
 
     std::set<int64_t> setInternalKeyPool;
     std::set<int64_t> setExternalKeyPool;
     int64_t m_max_keypool_index;
     std::map<CKeyID, int64_t> m_pool_key_to_index;
 
     int64_t nTimeFirstKey;
 
     /**
      * Private version of AddWatchOnly method which does not accept a timestamp,
      * and which will reset the wallet's nTimeFirstKey value to 1 if the watch
      * key did not previously have a timestamp associated with it. Because this
      * is an inherited virtual method, it is accessible despite being marked
      * private, but it is marked private anyway to encourage use of the other
      * AddWatchOnly which accepts a timestamp and sets nTimeFirstKey more
      * intelligently for more efficient rescans.
      */
     bool AddWatchOnly(const CScript &dest) override;
 
     std::unique_ptr<CWalletDBWrapper> dbw;
 
     /**
      * The following is used to keep track of how far behind the wallet is
      * from the chain sync, and to allow clients to block on us being caught up.
      *
      * Note that this is *not* how far we've processed, we may need some rescan
      * to have seen all transactions in the chain, but is only used to track
      * live BlockConnected callbacks.
      *
      * Protected by cs_main (see BlockUntilSyncedToCurrentChain)
      */
     const CBlockIndex *m_last_block_processed;
 
 public:
     const CChainParams &chainParams;
     /*
      * Main wallet lock.
      * This lock protects all the fields added by CWallet.
      */
     mutable CCriticalSection cs_wallet;
 
     /**
      * Get database handle used by this wallet. Ideally this function would not
      * be necessary.
      */
     CWalletDBWrapper &GetDBHandle() { return *dbw; }
 
     /**
      * Get a name for this wallet for logging/debugging purposes.
      */
     std::string GetName() const {
         if (dbw) {
             return dbw->GetName();
         } else {
             return "dummy";
         }
     }
 
     void LoadKeyPool(int64_t nIndex, const CKeyPool &keypool);
 
     // Map from Key ID to key metadata.
     std::map<CKeyID, CKeyMetadata> mapKeyMetadata;
 
     // Map from Script ID to key metadata (for watch-only keys).
     std::map<CScriptID, CKeyMetadata> m_script_metadata;
 
     typedef std::map<unsigned int, CMasterKey> MasterKeyMap;
     MasterKeyMap mapMasterKeys;
     unsigned int nMasterKeyMaxID;
 
     // Create wallet with dummy database handle
     explicit CWallet(const CChainParams &chainParamsIn)
         : dbw(new CWalletDBWrapper()), chainParams(chainParamsIn) {
         SetNull();
     }
 
     // Create wallet with passed-in database handle
     CWallet(const CChainParams &chainParamsIn,
             std::unique_ptr<CWalletDBWrapper> dbw_in)
         : dbw(std::move(dbw_in)), chainParams(chainParamsIn) {
         SetNull();
     }
 
     ~CWallet() {
         delete pwalletdbEncryption;
         pwalletdbEncryption = nullptr;
     }
 
     void SetNull() {
         nWalletVersion = FEATURE_BASE;
         nWalletMaxVersion = FEATURE_BASE;
         nMasterKeyMaxID = 0;
         pwalletdbEncryption = nullptr;
         nOrderPosNext = 0;
         nAccountingEntryNumber = 0;
         nNextResend = 0;
         nLastResend = 0;
         m_max_keypool_index = 0;
         nTimeFirstKey = 0;
         fBroadcastTransactions = false;
         fAbortRescan = false;
         fScanningWallet = false;
         nRelockTime = 0;
     }
 
     std::map<TxId, CWalletTx> mapWallet;
     std::list<CAccountingEntry> laccentries;
 
     typedef std::pair<CWalletTx *, CAccountingEntry *> TxPair;
     typedef std::multimap<int64_t, TxPair> TxItems;
     TxItems wtxOrdered;
 
     int64_t nOrderPosNext;
     uint64_t nAccountingEntryNumber;
     std::map<uint256, int> mapRequestCount;
 
     std::map<CTxDestination, CAddressBookData> mapAddressBook;
 
     std::set<COutPoint> setLockedCoins;
 
     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 {
         AssertLockHeld(cs_wallet);
         return nWalletMaxVersion >= wf;
     }
 
     /**
      * populate vCoins with vector of available COutputs.
      */
     void AvailableCoins(std::vector<COutput> &vCoins, bool fOnlySafe = true,
                         const CCoinControl *coinControl = nullptr,
                         const Amount nMinimumAmount = SATOSHI,
                         const Amount nMaximumAmount = MAX_MONEY,
                         const Amount nMinimumSumAmount = MAX_MONEY,
                         const uint64_t nMaximumCount = 0,
                         const int nMinDepth = 0,
                         const int nMaxDepth = 9999999) const;
 
     /**
      * Return list of available coins and locked coins grouped by non-change
      * output address.
      */
     std::map<CTxDestination, std::vector<COutput>> ListCoins() const;
 
     /**
      * Find non-change parent output.
      */
     const CTxOut &FindNonChangeParentOutput(const CTransaction &tx,
                                             int output) const;
 
     /**
      * 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, int nConfMine,
                             int nConfTheirs, uint64_t nMaxAncestors,
                             std::vector<COutput> vCoins,
                             std::set<CInputCoin> &setCoinsRet,
                             Amount &nValueRet) const;
 
     bool IsSpent(const TxId &txid, uint32_t n) const;
 
     bool IsLockedCoin(const TxId &txid, uint32_t n) const;
     void LockCoin(const COutPoint &output);
     void UnlockCoin(const COutPoint &output);
     void UnlockAllCoins();
     void ListLockedCoins(std::vector<COutPoint> &vOutpts) const;
 
     /*
      * Rescan abort properties
      */
     void AbortRescan() { fAbortRescan = true; }
     bool IsAbortingRescan() { return fAbortRescan; }
     bool IsScanning() { return fScanningWallet; }
 
     /**
      * keystore implementation
      * Generate a new key
      */
     CPubKey GenerateNewKey(CWalletDB &walletdb, bool internal = false);
     //! Adds a key to the store, and saves it to disk.
     bool AddKeyPubKey(const CKey &key, const CPubKey &pubkey) override;
     bool AddKeyPubKeyWithDB(CWalletDB &walletdb, const CKey &key,
                             const CPubKey &pubkey);
     //! Adds a key to the store, without saving it to disk (used by LoadWallet)
     bool LoadKey(const CKey &key, const CPubKey &pubkey) {
         return CCryptoKeyStore::AddKeyPubKey(key, pubkey);
     }
 
     //! Load metadata (used by LoadWallet)
     bool LoadKeyMetadata(const CKeyID &keyID, const CKeyMetadata &metadata);
     bool LoadScriptMetadata(const CScriptID &script_id,
                             const CKeyMetadata &metadata);
 
     bool LoadMinVersion(int nVersion) {
         AssertLockHeld(cs_wallet);
         nWalletVersion = nVersion;
         nWalletMaxVersion = std::max(nWalletMaxVersion, nVersion);
         return true;
     }
     void UpdateTimeFirstKey(int64_t nCreateTime);
 
     //! Adds an encrypted key to the store, and saves it to disk.
     bool AddCryptedKey(const CPubKey &vchPubKey,
                        const std::vector<uint8_t> &vchCryptedSecret) override;
     //! Adds an encrypted key to the store, without saving it to disk (used by
     //! LoadWallet)
     bool LoadCryptedKey(const CPubKey &vchPubKey,
                         const std::vector<uint8_t> &vchCryptedSecret);
     bool AddCScript(const CScript &redeemScript) override;
     bool LoadCScript(const CScript &redeemScript);
 
     //! Adds a destination data tuple to the store, and saves it to disk
     bool AddDestData(const CTxDestination &dest, const std::string &key,
                      const std::string &value);
     //! Erases a destination data tuple in the store and on disk
     bool EraseDestData(const CTxDestination &dest, const std::string &key);
     //! Adds a destination data tuple to the store, without saving it to disk
     bool LoadDestData(const CTxDestination &dest, const std::string &key,
                       const std::string &value);
     //! Look up a destination data tuple in the store, return true if found
     //! false otherwise
     bool GetDestData(const CTxDestination &dest, const std::string &key,
                      std::string *value) const;
     //! Get all destination values matching a prefix.
     std::vector<std::string> GetDestValues(const std::string &prefix) const;
 
     //! Adds a watch-only address to the store, and saves it to disk.
     bool AddWatchOnly(const CScript &dest, int64_t nCreateTime);
     bool RemoveWatchOnly(const CScript &dest) override;
     //! Adds a watch-only address to the store, without saving it to disk (used
     //! by LoadWallet)
     bool LoadWatchOnly(const CScript &dest);
 
     //! Holds a timestamp at which point the wallet is scheduled (externally) to
     //! be relocked. Caller must arrange for actual relocking to occur via
     //! Lock().
     int64_t nRelockTime;
 
     bool Unlock(const SecureString &strWalletPassphrase);
     bool ChangeWalletPassphrase(const SecureString &strOldWalletPassphrase,
                                 const SecureString &strNewWalletPassphrase);
     bool EncryptWallet(const SecureString &strWalletPassphrase);
 
     void GetKeyBirthTimes(std::map<CTxDestination, int64_t> &mapKeyBirth) const;
     unsigned int ComputeTimeSmart(const CWalletTx &wtx) const;
 
     /**
      * Increment the next transaction order id
      * @return next transaction order id
      */
     int64_t IncOrderPosNext(CWalletDB *pwalletdb = nullptr);
     DBErrors ReorderTransactions();
     bool AccountMove(std::string strFrom, std::string strTo,
                      const Amount nAmount, std::string strComment = "");
     bool GetLabelAddress(CPubKey &pubKey, const std::string &label,
                          bool bForceNew = false);
 
     void MarkDirty();
     bool AddToWallet(const CWalletTx &wtxIn, bool fFlushOnClose = true);
     bool LoadToWallet(const CWalletTx &wtxIn);
     void TransactionAddedToMempool(const CTransactionRef &tx) override;
     void
     BlockConnected(const std::shared_ptr<const CBlock> &pblock,
                    const CBlockIndex *pindex,
                    const std::vector<CTransactionRef> &vtxConflicted) override;
     void
     BlockDisconnected(const std::shared_ptr<const CBlock> &pblock) override;
     bool AddToWalletIfInvolvingMe(const CTransactionRef &tx,
                                   const CBlockIndex *pIndex, int posInBlock,
                                   bool fUpdate);
     int64_t RescanFromTime(int64_t startTime, bool update);
     CBlockIndex *ScanForWalletTransactions(CBlockIndex *pindexStart,
                                            CBlockIndex *pindexStop,
                                            bool fUpdate = false);
     void TransactionRemovedFromMempool(const CTransactionRef &ptx) override;
     void ReacceptWalletTransactions();
     void ResendWalletTransactions(int64_t nBestBlockTime,
                                   CConnman *connman) override;
     // ResendWalletTransactionsBefore may only be called if
     // fBroadcastTransactions!
     std::vector<uint256> ResendWalletTransactionsBefore(int64_t nTime,
                                                         CConnman *connman);
     Amount GetBalance() const;
     Amount GetUnconfirmedBalance() const;
     Amount GetImmatureBalance() const;
     Amount GetWatchOnlyBalance() const;
     Amount GetUnconfirmedWatchOnlyBalance() const;
     Amount GetImmatureWatchOnlyBalance() const;
     Amount GetLegacyBalance(const isminefilter &filter, int minDepth,
                             const std::string *account) const;
     Amount GetAvailableBalance(const CCoinControl *coinControl = nullptr) const;
 
     /**
      * 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 keepReserveKey);
     bool SignTransaction(CMutableTransaction &tx);
 
     /**
      * 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(const std::vector<CRecipient> &vecSend,
                            CTransactionRef &tx, CReserveKey &reservekey,
                            Amount &nFeeRet, int &nChangePosInOut,
                            std::string &strFailReason,
                            const CCoinControl &coinControl, bool sign = true);
     bool CommitTransaction(
         CTransactionRef tx, mapValue_t mapValue,
         std::vector<std::pair<std::string, std::string>> orderForm,
         std::string fromAccount, CReserveKey &reservekey, CConnman *connman,
         CValidationState &state);
 
     void ListAccountCreditDebit(const std::string &strAccount,
                                 std::list<CAccountingEntry> &entries);
     bool AddAccountingEntry(const CAccountingEntry &);
     bool AddAccountingEntry(const CAccountingEntry &, CWalletDB *pwalletdb);
     template <typename ContainerType>
     bool DummySignTx(CMutableTransaction &txNew,
                      const ContainerType &coins) const;
 
     static CFeeRate fallbackFee;
 
     bool NewKeyPool();
     size_t KeypoolCountExternalKeys();
     bool TopUpKeyPool(unsigned int kpSize = 0);
     void ReserveKeyFromKeyPool(int64_t &nIndex, CKeyPool &keypool,
                                bool fRequestedInternal);
     void KeepKey(int64_t nIndex);
     void ReturnKey(int64_t nIndex, bool fInternal, const CPubKey &pubkey);
     bool GetKeyFromPool(CPubKey &key, bool internal = false);
     int64_t GetOldestKeyPoolTime();
     /**
      * Marks all keys in the keypool up to and including reserve_key as used.
      */
     void MarkReserveKeysAsUsed(int64_t keypool_id);
     const std::map<CKeyID, int64_t> &GetAllReserveKeys() const {
         return m_pool_key_to_index;
     }
     /** Does the wallet have at least min_keys in the keypool? */
     bool HasUnusedKeys(size_t min_keys) const;
 
     std::set<std::set<CTxDestination>> GetAddressGroupings();
     std::map<CTxDestination, Amount> GetAddressBalances();
 
     std::set<CTxDestination> GetLabelAddresses(const std::string &label) const;
 
     isminetype IsMine(const CTxIn &txin) const;
     /**
      * Returns amount of debit if the input matches the filter, otherwise
      * returns 0
      */
     Amount GetDebit(const CTxIn &txin, const isminefilter &filter) const;
     isminetype IsMine(const CTxOut &txout) const;
     Amount GetCredit(const CTxOut &txout, const isminefilter &filter) const;
     bool IsChange(const CTxOut &txout) const;
     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 SetBestChain(const CBlockLocator &loc) override;
 
     DBErrors LoadWallet(bool &fFirstRunRet);
     DBErrors ZapWalletTx(std::vector<CWalletTx> &vWtx);
     DBErrors ZapSelectTx(std::vector<TxId> &txIdsIn,
                          std::vector<TxId> &txIdsOut);
 
     bool SetAddressBook(const CTxDestination &address,
                         const std::string &strName, const std::string &purpose);
 
     bool DelAddressBook(const CTxDestination &address);
 
     const std::string &GetLabelName(const CScript &scriptPubKey) const;
 
     void Inventory(const uint256 &hash) override {
         LOCK(cs_wallet);
         std::map<uint256, int>::iterator mi = mapRequestCount.find(hash);
         if (mi != mapRequestCount.end()) {
             (*mi).second++;
         }
     }
 
     void GetScriptForMining(std::shared_ptr<CReserveScript> &script);
 
     unsigned int GetKeyPoolSize() {
         // set{Ex,In}ternalKeyPool
         AssertLockHeld(cs_wallet);
         return setInternalKeyPool.size() + setExternalKeyPool.size();
     }
 
     //! signify that a particular wallet feature is now used. this may change
     //! nWalletVersion and nWalletMaxVersion if those are lower
     bool SetMinVersion(enum WalletFeature, CWalletDB *pwalletdbIn = nullptr,
                        bool fExplicit = false);
 
     //! change which version we're allowed to upgrade to (note that this does
     //! not immediately imply upgrading to that format)
     bool SetMaxVersion(int nVersion);
 
     //! get the current wallet format (the oldest client version guaranteed to
     //! understand this wallet)
     int GetVersion() {
         LOCK(cs_wallet);
         return nWalletVersion;
     }
 
     //! Get wallet transactions that conflict with given transaction (spend same
     //! outputs)
     std::set<TxId> GetConflicts(const TxId &txid) const;
 
     //! Check if a given transaction has any of its outputs spent by another
     //! transaction in the wallet
     bool HasWalletSpend(const TxId &txid) const;
 
     //! Flush wallet (bitdb flush)
     void Flush(bool shutdown = false);
 
     /**
      * 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;
 
     /** 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(const TxId &txid);
 
     /**
      * Initializes the wallet, returns a new CWallet instance or a null pointer
      * in case of an error.
      */
     static CWallet *CreateWalletFromFile(const CChainParams &chainParams,
                                          const std::string walletFile);
 
     /**
      * Wallet post-init setup
      * Gives the wallet a chance to register repetitive tasks and complete
      * post-init tasks
      */
     void postInitProcess(CScheduler &scheduler);
 
     bool BackupWallet(const std::string &strDest);
 
     /* Set the HD chain model (chain child index counters) */
     bool SetHDChain(const CHDChain &chain, bool memonly);
     const CHDChain &GetHDChain() const { return hdChain; }
 
     /* Returns true if HD is enabled */
     bool IsHDEnabled() const;
 
     /* Generates a new HD master key (will not be activated) */
     CPubKey GenerateNewHDMasterKey();
 
     /**
      * Set the current HD master key (will reset the chain child index counters)
      * If possibleOldChain is provided, the parameters from the old chain
      * (version) will be preserved.
      */
     bool SetHDMasterKey(const CPubKey &key,
                         CHDChain *possibleOldChain = nullptr);
 
     /**
      * 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();
 };
 
 /** A key allocated from the key pool. */
 class CReserveKey final : public CReserveScript {
 protected:
     CWallet *pwallet;
     int64_t nIndex;
     CPubKey vchPubKey;
     bool fInternal;
 
 public:
     explicit CReserveKey(CWallet *pwalletIn) {
         nIndex = -1;
         pwallet = pwalletIn;
         fInternal = false;
     }
 
+    CReserveKey() = default;
+    CReserveKey(const CReserveKey &) = delete;
+    CReserveKey &operator=(const CReserveKey &) = delete;
+
     ~CReserveKey() { ReturnKey(); }
 
     void ReturnKey();
     bool GetReservedKey(CPubKey &pubkey, bool internal = false);
     void KeepKey();
     void KeepScript() override { KeepKey(); }
 };
 
 /**
  * Account information.
  * Stored in wallet with key "acc"+string account name.
  */
 class CAccount {
 public:
     CPubKey vchPubKey;
 
     CAccount() { SetNull(); }
 
     void SetNull() { vchPubKey = CPubKey(); }
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         int nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) {
             READWRITE(nVersion);
         }
 
         READWRITE(vchPubKey);
     }
 };
 
 // Helper for producing a bunch of max-sized low-S signatures (eg 72 bytes)
 // ContainerType is meant to hold pair<CWalletTx *, int>, and be iterable so
 // that each entry corresponds to each vIn, in order.
 template <typename ContainerType>
 bool CWallet::DummySignTx(CMutableTransaction &txNew,
                           const ContainerType &coins) const {
     // Fill in dummy signatures for fee calculation.
     int nIn = 0;
     for (const auto &coin : coins) {
         const CScript &scriptPubKey = coin.txout.scriptPubKey;
         SignatureData sigdata;
 
         if (!ProduceSignature(DummySignatureCreator(this), scriptPubKey,
                               sigdata)) {
             return false;
         } else {
             UpdateTransaction(txNew, nIn, sigdata);
         }
 
         nIn++;
     }
 
     return true;
 }
 
 #endif // BITCOIN_WALLET_WALLET_H