Merge bitcoin/bitcoin#25005: wallet: remove extra wtx lookup in 'AvailableCoins' + several code cleanups.

fd5c996d1609e6f88769f6f3ef0c322e3435b3aa wallet: GetAvailableBalance, remove double walk-through every available coin (furszy)
162d4ad10f28c5fa38551d69ce9b296ab3933c77 wallet: add 'only_spendable' filter to AvailableCoins (furszy)
cdf185ccfb2085e5a4bf82d833392d74b748aeff wallet: remove unused IsSpentKey(hash, index) method (furszy)
4b83bf8dbcf6b8b1c1293575391e90ac7e21b0e0 wallet: avoid extra IsSpentKey -> GetWalletTx lookups (furszy)
3d8a2822570e3cf4d1bc4f9d59b5dcb0145920ad wallet: decouple IsSpentKey(scriptPubKey) from IsSpentKey(hash, n) (furszy)
a06fa94ff81e2bccef0316ea5ec4eca0f4de5071 wallet: IsSpent, 'COutPoint' arg instead of (hash, index) (furszy)
91902b77202fc636edb3db587cb6e87d9fb9b60a wallet: IsLockedCoin, 'COutPoint' arg instead of (hash, index) (furszy)
9472ca0a65396206b3078bddf98f4c1807be2d82 wallet: AvailableCoins, don't call 'wtx.tx->vout[i]' multiple times (furszy)
4ce235ef8f9a9dddc52d7ab60c8f71bda1d38873 wallet: return 'CoinsResult' struct in `AvailableCoins` (furszy)

Pull request description:

  This started in #24845 but grew out of scope of it.

  So, points tackled:

  1) Avoid extra `GetWalletTx` lookups inside `AvailableCoins -> IsSpentKey`.
      `IsSpentKey` was receiving the tx hash and index to internally lookup the tx inside the wallet's map. As all the `IsSpentKey` function callers already have the wtx available, them can provide the `scriptPubKey` directly.

  2) Most of the time, we call `Wallet::AvailableCoins`, and later on the process, skip the non-spendable coins from the result in subsequent for-loops. So to speedup the process: introduced the ability to filter by "only_spendable" coins inside `Wallet::AvailableCoins` directly.
  (the non-spendable coins skip examples are inside `AttemptSelection->GroupOutputs` and `GetAvailableBalance`).

  4) Refactored `AvailableCoins` in several ways:

     a) Now it will return a new struct `CoinsResult` instead of receiving the vCoins vector reference (which was being cleared at the beginning of the method anyway). --> this is coming from #24845 but cherry-picked it here too to make the following commits look nicer.

     b) Unified all the 'wtx.tx->vout[I]' calls into a single call (coming from this comment https://github.com/bitcoin/bitcoin/pull/24699#discussion_r854163032).

  5) The wallet `IsLockedCoin` and `IsSpent` methods now accept an `OutPoint` instead of a hash:index. Which let me cleanup a bunch of extra code.

  6) Speeded up the wallet 'GetAvailableBalance': filtering `AvailableCoins` by spendable outputs only and using the 'AvailableCoins' retrieved `total_amount` instead of looping over all the retrieved coins once more.

  -------------------------------------------------------

  Side topic, all this process will look even nicer with #25218

ACKs for top commit:
  achow101:
    ACK fd5c996d1609e6f88769f6f3ef0c322e3435b3aa
  brunoerg:
    crACK fd5c996d1609e6f88769f6f3ef0c322e3435b3aa
  w0xlt:
    Code Review ACK https://github.com/bitcoin/bitcoin/pull/25005/commits/fd5c996d1609e6f88769f6f3ef0c322e3435b3aa

Tree-SHA512: 376a85476f907f4f7d1fc3de74b3dbe159b8cc24687374d8739711ad202ea07a33e86f4e66dece836da3ae6985147119fe584f6e672f11d0450ba6bd165b3220

9 files changed, 118 insertions, 107 deletions

diff --git a/src/wallet/interfaces.cpp b/src/wallet/interfaces.cpp
index e1203817e0..f54b2c83d2 100644
--- a/src/wallet/interfaces.cpp
+++ b/src/wallet/interfaces.cpp
@@ -110,7 +110,7 @@ WalletTxOut MakeWalletTxOut(const CWallet& wallet,
     result.txout = wtx.tx->vout[n];
     result.time = wtx.GetTxTime();
     result.depth_in_main_chain = depth;
-    result.is_spent = wallet.IsSpent(wtx.GetHash(), n);
+    result.is_spent = wallet.IsSpent(COutPoint(wtx.GetHash(), n));
     return result;
 }
 
@@ -121,7 +121,7 @@ WalletTxOut MakeWalletTxOut(const CWallet& wallet,
     result.txout = output.txout;
     result.time = output.time;
     result.depth_in_main_chain = output.depth;
-    result.is_spent = wallet.IsSpent(output.outpoint.hash, output.outpoint.n);
+    result.is_spent = wallet.IsSpent(output.outpoint);
     return result;
 }
 
@@ -245,7 +245,7 @@ public:
     bool isLockedCoin(const COutPoint& output) override
     {
         LOCK(m_wallet->cs_wallet);
-        return m_wallet->IsLockedCoin(output.hash, output.n);
+        return m_wallet->IsLockedCoin(output);
     }
     void listLockedCoins(std::vector<COutPoint>& outputs) override
     {
diff --git a/src/wallet/receive.cpp b/src/wallet/receive.cpp
index 8cce07b921..8de4017371 100644
--- a/src/wallet/receive.cpp
+++ b/src/wallet/receive.cpp
@@ -204,10 +204,9 @@ CAmount CachedTxGetAvailableCredit(const CWallet& wallet, const CWalletTx& wtx,
     bool allow_used_addresses = (filter & ISMINE_USED) || !wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
     CAmount nCredit = 0;
     uint256 hashTx = wtx.GetHash();
-    for (unsigned int i = 0; i < wtx.tx->vout.size(); i++)
-    {
-        if (!wallet.IsSpent(hashTx, i) && (allow_used_addresses || !wallet.IsSpentKey(hashTx, i))) {
-            const CTxOut &txout = wtx.tx->vout[i];
+    for (unsigned int i = 0; i < wtx.tx->vout.size(); i++) {
+        const CTxOut& txout = wtx.tx->vout[i];
+        if (!wallet.IsSpent(COutPoint(hashTx, i)) && (allow_used_addresses || !wallet.IsSpentKey(txout.scriptPubKey))) {
             nCredit += OutputGetCredit(wallet, txout, filter);
             if (!MoneyRange(nCredit))
                 throw std::runtime_error(std::string(__func__) + " : value out of range");
@@ -371,15 +370,15 @@ std::map<CTxDestination, CAmount> GetAddressBalances(const CWallet& wallet)
             if (nDepth < (CachedTxIsFromMe(wallet, wtx, ISMINE_ALL) ? 0 : 1))
                 continue;
 
-            for (unsigned int i = 0; i < wtx.tx->vout.size(); i++)
-            {
+            for (unsigned int i = 0; i < wtx.tx->vout.size(); i++) {
+                const auto& output = wtx.tx->vout[i];
                 CTxDestination addr;
-                if (!wallet.IsMine(wtx.tx->vout[i]))
+                if (!wallet.IsMine(output))
                     continue;
-                if(!ExtractDestination(wtx.tx->vout[i].scriptPubKey, addr))
+                if(!ExtractDestination(output.scriptPubKey, addr))
                     continue;
 
-                CAmount n = wallet.IsSpent(walletEntry.first, i) ? 0 : wtx.tx->vout[i].nValue;
+                CAmount n = wallet.IsSpent(COutPoint(walletEntry.first, i)) ? 0 : output.nValue;
                 balances[addr] += n;
             }
         }
diff --git a/src/wallet/rpc/coins.cpp b/src/wallet/rpc/coins.cpp
index 2649fa586c..ad59cc94ff 100644
--- a/src/wallet/rpc/coins.cpp
+++ b/src/wallet/rpc/coins.cpp
@@ -341,11 +341,11 @@ RPCHelpMan lockunspent()
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout index out of bounds");
         }
 
-        if (pwallet->IsSpent(outpt.hash, outpt.n)) {
+        if (pwallet->IsSpent(outpt)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, expected unspent output");
         }
 
-        const bool is_locked = pwallet->IsLockedCoin(outpt.hash, outpt.n);
+        const bool is_locked = pwallet->IsLockedCoin(outpt);
 
         if (fUnlock && !is_locked) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, expected locked output");
@@ -638,7 +638,7 @@ RPCHelpMan listunspent()
         cctl.m_max_depth = nMaxDepth;
         cctl.m_include_unsafe_inputs = include_unsafe;
         LOCK(pwallet->cs_wallet);
-        AvailableCoinsListUnspent(*pwallet, vecOutputs, &cctl, nMinimumAmount, nMaximumAmount, nMinimumSumAmount, nMaximumCount);
+        vecOutputs = AvailableCoinsListUnspent(*pwallet, &cctl, nMinimumAmount, nMaximumAmount, nMinimumSumAmount, nMaximumCount).coins;
     }
 
     LOCK(pwallet->cs_wallet);
@@ -649,7 +649,7 @@ RPCHelpMan listunspent()
         CTxDestination address;
         const CScript& scriptPubKey = out.txout.scriptPubKey;
         bool fValidAddress = ExtractDestination(scriptPubKey, address);
-        bool reused = avoid_reuse && pwallet->IsSpentKey(out.outpoint.hash, out.outpoint.n);
+        bool reused = avoid_reuse && pwallet->IsSpentKey(scriptPubKey);
 
         if (destinations.size() && (!fValidAddress || !destinations.count(address)))
             continue;
diff --git a/src/wallet/rpc/spend.cpp b/src/wallet/rpc/spend.cpp
index 2520cd2532..e2ea2b691d 100644
--- a/src/wallet/rpc/spend.cpp
+++ b/src/wallet/rpc/spend.cpp
@@ -1367,7 +1367,6 @@ RPCHelpMan sendall()
 
             CMutableTransaction rawTx{ConstructTransaction(options["inputs"], recipient_key_value_pairs, options["locktime"], rbf)};
             LOCK(pwallet->cs_wallet);
-            std::vector<COutput> all_the_utxos;
 
             CAmount total_input_value(0);
             bool send_max{options.exists("send_max") ? options["send_max"].get_bool() : false};
@@ -1375,7 +1374,7 @@ RPCHelpMan sendall()
                 throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot combine send_max with specific inputs.");
             } else if (options.exists("inputs")) {
                 for (const CTxIn& input : rawTx.vin) {
-                    if (pwallet->IsSpent(input.prevout.hash, input.prevout.n)) {
+                    if (pwallet->IsSpent(input.prevout)) {
                         throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Input not available. UTXO (%s:%d) was already spent.", input.prevout.hash.ToString(), input.prevout.n));
                     }
                     const CWalletTx* tx{pwallet->GetWalletTx(input.prevout.hash)};
@@ -1385,8 +1384,7 @@ RPCHelpMan sendall()
                     total_input_value += tx->tx->vout[input.prevout.n].nValue;
                 }
             } else {
-                AvailableCoins(*pwallet, all_the_utxos, &coin_control, fee_rate, /*nMinimumAmount=*/0);
-                for (const COutput& output : all_the_utxos) {
+                for (const COutput& output : AvailableCoins(*pwallet, &coin_control, fee_rate, /*nMinimumAmount=*/0).coins) {
                     CHECK_NONFATAL(output.input_bytes > 0);
                     if (send_max && fee_rate.GetFee(output.input_bytes) > output.txout.nValue) {
                         continue;
diff --git a/src/wallet/spend.cpp b/src/wallet/spend.cpp
index ce99aeefe5..60a28a22e9 100644
--- a/src/wallet/spend.cpp
+++ b/src/wallet/spend.cpp
@@ -84,12 +84,18 @@ TxSize CalculateMaximumSignedTxSize(const CTransaction &tx, const CWallet *walle
     return CalculateMaximumSignedTxSize(tx, wallet, txouts, coin_control);
 }
 
-void AvailableCoins(const CWallet& wallet, std::vector<COutput>& vCoins, const CCoinControl* coinControl, std::optional<CFeeRate> feerate, const CAmount& nMinimumAmount, const CAmount& nMaximumAmount, const CAmount& nMinimumSumAmount, const uint64_t nMaximumCount)
+CoinsResult AvailableCoins(const CWallet& wallet,
+                           const CCoinControl* coinControl,
+                           std::optional<CFeeRate> feerate,
+                           const CAmount& nMinimumAmount,
+                           const CAmount& nMaximumAmount,
+                           const CAmount& nMinimumSumAmount,
+                           const uint64_t nMaximumCount,
+                           bool only_spendable)
 {
     AssertLockHeld(wallet.cs_wallet);
 
-    vCoins.clear();
-    CAmount nTotal = 0;
+    CoinsResult result;
     // 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 = !wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE) || (coinControl && !coinControl->m_avoid_address_reuse);
@@ -159,76 +165,81 @@ void AvailableCoins(const CWallet& wallet, std::vector<COutput>& vCoins, const C
         bool tx_from_me = CachedTxIsFromMe(wallet, wtx, ISMINE_ALL);
 
         for (unsigned int i = 0; i < wtx.tx->vout.size(); i++) {
+            const CTxOut& output = wtx.tx->vout[i];
+            const COutPoint outpoint(wtxid, i);
+
             // Only consider selected coins if add_inputs is false
-            if (coinControl && !coinControl->m_add_inputs && !coinControl->IsSelected(COutPoint(entry.first, i))) {
+            if (coinControl && !coinControl->m_add_inputs && !coinControl->IsSelected(outpoint)) {
                 continue;
             }
 
-            if (wtx.tx->vout[i].nValue < nMinimumAmount || wtx.tx->vout[i].nValue > nMaximumAmount)
+            if (output.nValue < nMinimumAmount || output.nValue > nMaximumAmount)
                 continue;
 
-            if (coinControl && coinControl->HasSelected() && !coinControl->fAllowOtherInputs && !coinControl->IsSelected(COutPoint(entry.first, i)))
+            if (coinControl && coinControl->HasSelected() && !coinControl->fAllowOtherInputs && !coinControl->IsSelected(outpoint))
                 continue;
 
-            if (wallet.IsLockedCoin(entry.first, i))
+            if (wallet.IsLockedCoin(outpoint))
                 continue;
 
-            if (wallet.IsSpent(wtxid, i))
+            if (wallet.IsSpent(outpoint))
                 continue;
 
-            isminetype mine = wallet.IsMine(wtx.tx->vout[i]);
+            isminetype mine = wallet.IsMine(output);
 
             if (mine == ISMINE_NO) {
                 continue;
             }
 
-            if (!allow_used_addresses && wallet.IsSpentKey(wtxid, i)) {
+            if (!allow_used_addresses && wallet.IsSpentKey(output.scriptPubKey)) {
                 continue;
             }
 
-            std::unique_ptr<SigningProvider> provider = wallet.GetSolvingProvider(wtx.tx->vout[i].scriptPubKey);
+            std::unique_ptr<SigningProvider> provider = wallet.GetSolvingProvider(output.scriptPubKey);
 
-            bool solvable = provider ? IsSolvable(*provider, wtx.tx->vout[i].scriptPubKey) : false;
+            bool solvable = provider ? IsSolvable(*provider, output.scriptPubKey) : false;
             bool spendable = ((mine & ISMINE_SPENDABLE) != ISMINE_NO) || (((mine & ISMINE_WATCH_ONLY) != ISMINE_NO) && (coinControl && coinControl->fAllowWatchOnly && solvable));
-            int input_bytes = GetTxSpendSize(wallet, wtx, i, (coinControl && coinControl->fAllowWatchOnly));
 
-            vCoins.emplace_back(COutPoint(wtx.GetHash(), i), wtx.tx->vout.at(i), nDepth, input_bytes, spendable, solvable, safeTx, wtx.GetTxTime(), tx_from_me, feerate);
+            // Filter by spendable outputs only
+            if (!spendable && only_spendable) continue;
+
+            int input_bytes = GetTxSpendSize(wallet, wtx, i, (coinControl && coinControl->fAllowWatchOnly));
+            result.coins.emplace_back(outpoint, output, nDepth, input_bytes, spendable, solvable, safeTx, wtx.GetTxTime(), tx_from_me, feerate);
+            result.total_amount += output.nValue;
 
             // Checks the sum amount of all UTXO's.
             if (nMinimumSumAmount != MAX_MONEY) {
-                nTotal += wtx.tx->vout[i].nValue;
-
-                if (nTotal >= nMinimumSumAmount) {
-                    return;
+                if (result.total_amount >= nMinimumSumAmount) {
+                    return result;
                 }
             }
 
             // Checks the maximum number of UTXO's.
-            if (nMaximumCount > 0 && vCoins.size() >= nMaximumCount) {
-                return;
+            if (nMaximumCount > 0 && result.coins.size() >= nMaximumCount) {
+                return result;
             }
         }
     }
+
+    return result;
 }
 
-void AvailableCoinsListUnspent(const CWallet& wallet, std::vector<COutput>& vCoins, const CCoinControl* coinControl, const CAmount& nMinimumAmount, const CAmount& nMaximumAmount, const CAmount& nMinimumSumAmount, const uint64_t nMaximumCount)
+CoinsResult AvailableCoinsListUnspent(const CWallet& wallet, const CCoinControl* coinControl, const CAmount& nMinimumAmount, const CAmount& nMaximumAmount, const CAmount& nMinimumSumAmount, const uint64_t nMaximumCount)
 {
-    AvailableCoins(wallet, vCoins, coinControl, /*feerate=*/ std::nullopt, nMinimumAmount, nMaximumAmount, nMinimumSumAmount, nMaximumCount);
+    return AvailableCoins(wallet, coinControl, /*feerate=*/ std::nullopt, nMinimumAmount, nMaximumAmount, nMinimumSumAmount, nMaximumCount, /*only_spendable=*/false);
 }
 
 CAmount GetAvailableBalance(const CWallet& wallet, const CCoinControl* coinControl)
 {
     LOCK(wallet.cs_wallet);
-
-    CAmount balance = 0;
-    std::vector<COutput> vCoins;
-    AvailableCoinsListUnspent(wallet, vCoins, coinControl);
-    for (const COutput& out : vCoins) {
-        if (out.spendable) {
-            balance += out.txout.nValue;
-        }
-    }
-    return balance;
+    return AvailableCoins(wallet,
+                          coinControl,
+                          std::nullopt, /*feerate=*/
+                          1,            /*nMinimumAmount*/
+                          MAX_MONEY,    /*nMaximumAmount*/
+                          MAX_MONEY,    /*nMinimumSumAmount*/
+                          0             /*nMaximumCount*/
+                          ).total_amount;
 }
 
 const CTxOut& FindNonChangeParentOutput(const CWallet& wallet, const CTransaction& tx, int output)
@@ -260,11 +271,8 @@ std::map<CTxDestination, std::vector<COutput>> ListCoins(const CWallet& wallet)
     AssertLockHeld(wallet.cs_wallet);
 
     std::map<CTxDestination, std::vector<COutput>> result;
-    std::vector<COutput> availableCoins;
-
-    AvailableCoinsListUnspent(wallet, availableCoins);
 
-    for (const COutput& coin : availableCoins) {
+    for (const COutput& coin : AvailableCoinsListUnspent(wallet).coins) {
         CTxDestination address;
         if ((coin.spendable || (wallet.IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS) && coin.solvable)) &&
             ExtractDestination(FindNonChangeParentOutput(wallet, coin.outpoint).scriptPubKey, address)) {
@@ -791,11 +799,16 @@ static std::optional<CreatedTransactionResult> CreateTransactionInternal(
     CAmount selection_target = recipients_sum + not_input_fees;
 
     // Get available coins
-    std::vector<COutput> vAvailableCoins;
-    AvailableCoins(wallet, vAvailableCoins, &coin_control, coin_selection_params.m_effective_feerate, 1, MAX_MONEY, MAX_MONEY, 0);
+    auto res_available_coins = AvailableCoins(wallet,
+                                              &coin_control,
+                                              coin_selection_params.m_effective_feerate,
+                                              1,            /*nMinimumAmount*/
+                                              MAX_MONEY,    /*nMaximumAmount*/
+                                              MAX_MONEY,    /*nMinimumSumAmount*/
+                                              0);           /*nMaximumCount*/
 
     // Choose coins to use
-    std::optional<SelectionResult> result = SelectCoins(wallet, vAvailableCoins, /*nTargetValue=*/selection_target, coin_control, coin_selection_params);
+    std::optional<SelectionResult> result = SelectCoins(wallet, res_available_coins.coins, /*nTargetValue=*/selection_target, coin_control, coin_selection_params);
     if (!result) {
         error = _("Insufficient funds");
         return std::nullopt;
diff --git a/src/wallet/spend.h b/src/wallet/spend.h
index 988058a25a..cba42d6fae 100644
--- a/src/wallet/spend.h
+++ b/src/wallet/spend.h
@@ -34,16 +34,29 @@ struct TxSize {
 TxSize CalculateMaximumSignedTxSize(const CTransaction& tx, const CWallet* wallet, const std::vector<CTxOut>& txouts, const CCoinControl* coin_control = nullptr);
 TxSize CalculateMaximumSignedTxSize(const CTransaction& tx, const CWallet* wallet, const CCoinControl* coin_control = nullptr) EXCLUSIVE_LOCKS_REQUIRED(wallet->cs_wallet);
 
+struct CoinsResult {
+    std::vector<COutput> coins;
+    // Sum of all the coins amounts
+    CAmount total_amount{0};
+};
 /**
- * populate vCoins with vector of available COutputs.
+ * Return vector of available COutputs.
+ * By default, returns only the spendable coins.
  */
-void AvailableCoins(const CWallet& wallet, std::vector<COutput>& vCoins, const CCoinControl* coinControl = nullptr, std::optional<CFeeRate> feerate = std::nullopt, const CAmount& nMinimumAmount = 1, const CAmount& nMaximumAmount = MAX_MONEY, const CAmount& nMinimumSumAmount = MAX_MONEY, const uint64_t nMaximumCount = 0) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
+CoinsResult AvailableCoins(const CWallet& wallet,
+                           const CCoinControl* coinControl = nullptr,
+                           std::optional<CFeeRate> feerate = std::nullopt,
+                           const CAmount& nMinimumAmount = 1,
+                           const CAmount& nMaximumAmount = MAX_MONEY,
+                           const CAmount& nMinimumSumAmount = MAX_MONEY,
+                           const uint64_t nMaximumCount = 0,
+                           bool only_spendable = true) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
 
 /**
  * Wrapper function for AvailableCoins which skips the `feerate` parameter. Use this function
  * to list all available coins (e.g. listunspent RPC) while not intending to fund a transaction.
  */
-void AvailableCoinsListUnspent(const CWallet& wallet, std::vector<COutput>& vCoins, const CCoinControl* coinControl = nullptr, const CAmount& nMinimumAmount = 1, const CAmount& nMaximumAmount = MAX_MONEY, const CAmount& nMinimumSumAmount = MAX_MONEY, const uint64_t nMaximumCount = 0) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
+CoinsResult AvailableCoinsListUnspent(const CWallet& wallet, const CCoinControl* coinControl = nullptr, const CAmount& nMinimumAmount = 1, const CAmount& nMaximumAmount = MAX_MONEY, const CAmount& nMinimumSumAmount = MAX_MONEY, const uint64_t nMaximumCount = 0) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
 
 CAmount GetAvailableBalance(const CWallet& wallet, const CCoinControl* coinControl = nullptr);
 
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 70863f5464..0c03b2f4a2 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -583,9 +583,7 @@ BOOST_FIXTURE_TEST_CASE(ListCoinsTest, ListCoinsTestingSetup)
     // Lock both coins. Confirm number of available coins drops to 0.
     {
         LOCK(wallet->cs_wallet);
-        std::vector<COutput> available;
-        AvailableCoinsListUnspent(*wallet, available);
-        BOOST_CHECK_EQUAL(available.size(), 2U);
+        BOOST_CHECK_EQUAL(AvailableCoinsListUnspent(*wallet).coins.size(), 2U);
     }
     for (const auto& group : list) {
         for (const auto& coin : group.second) {
@@ -595,9 +593,7 @@ BOOST_FIXTURE_TEST_CASE(ListCoinsTest, ListCoinsTestingSetup)
     }
     {
         LOCK(wallet->cs_wallet);
-        std::vector<COutput> available;
-        AvailableCoinsListUnspent(*wallet, available);
-        BOOST_CHECK_EQUAL(available.size(), 0U);
+        BOOST_CHECK_EQUAL(AvailableCoinsListUnspent(*wallet).coins.size(), 0U);
     }
     // Confirm ListCoins still returns same result as before, despite coins
     // being locked.
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 910562e669..ea306183ef 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -629,14 +629,12 @@ void CWallet::SyncMetaData(std::pair<TxSpends::iterator, TxSpends::iterator> ran
  * Outpoint is spent if any non-conflicted transaction
  * spends it:
  */
-bool CWallet::IsSpent(const uint256& hash, unsigned int n) const
+bool CWallet::IsSpent(const COutPoint& outpoint) const
 {
-    const COutPoint outpoint(hash, n);
     std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range;
     range = mapTxSpends.equal_range(outpoint);
 
-    for (TxSpends::const_iterator it = range.first; it != range.second; ++it)
-    {
+    for (TxSpends::const_iterator it = range.first; it != range.second; ++it) {
         const uint256& wtxid = it->second;
         std::map<uint256, CWalletTx>::const_iterator mit = mapWallet.find(wtxid);
         if (mit != mapWallet.end()) {
@@ -908,35 +906,31 @@ void CWallet::SetSpentKeyState(WalletBatch& batch, const uint256& hash, unsigned
     }
 }
 
-bool CWallet::IsSpentKey(const uint256& hash, unsigned int n) const
+bool CWallet::IsSpentKey(const CScript& scriptPubKey) const
 {
     AssertLockHeld(cs_wallet);
-    const CWalletTx* srctx = GetWalletTx(hash);
-    if (srctx) {
-        assert(srctx->tx->vout.size() > n);
-        CTxDestination dest;
-        if (!ExtractDestination(srctx->tx->vout[n].scriptPubKey, dest)) {
-            return false;
-        }
-        if (IsAddressUsed(dest)) {
-            return true;
-        }
-        if (IsLegacy()) {
-            LegacyScriptPubKeyMan* spk_man = GetLegacyScriptPubKeyMan();
-            assert(spk_man != nullptr);
-            for (const auto& keyid : GetAffectedKeys(srctx->tx->vout[n].scriptPubKey, *spk_man)) {
-                WitnessV0KeyHash wpkh_dest(keyid);
-                if (IsAddressUsed(wpkh_dest)) {
-                    return true;
-                }
-                ScriptHash sh_wpkh_dest(GetScriptForDestination(wpkh_dest));
-                if (IsAddressUsed(sh_wpkh_dest)) {
-                    return true;
-                }
-                PKHash pkh_dest(keyid);
-                if (IsAddressUsed(pkh_dest)) {
-                    return true;
-                }
+    CTxDestination dest;
+    if (!ExtractDestination(scriptPubKey, dest)) {
+        return false;
+    }
+    if (IsAddressUsed(dest)) {
+        return true;
+    }
+    if (IsLegacy()) {
+        LegacyScriptPubKeyMan* spk_man = GetLegacyScriptPubKeyMan();
+        assert(spk_man != nullptr);
+        for (const auto& keyid : GetAffectedKeys(scriptPubKey, *spk_man)) {
+            WitnessV0KeyHash wpkh_dest(keyid);
+            if (IsAddressUsed(wpkh_dest)) {
+                return true;
+            }
+            ScriptHash sh_wpkh_dest(GetScriptForDestination(wpkh_dest));
+            if (IsAddressUsed(sh_wpkh_dest)) {
+                return true;
+            }
+            PKHash pkh_dest(keyid);
+            if (IsAddressUsed(pkh_dest)) {
+                return true;
             }
         }
     }
@@ -2450,12 +2444,10 @@ bool CWallet::UnlockAllCoins()
     return success;
 }
 
-bool CWallet::IsLockedCoin(uint256 hash, unsigned int n) const
+bool CWallet::IsLockedCoin(const COutPoint& output) const
 {
     AssertLockHeld(cs_wallet);
-    COutPoint outpt(hash, n);
-
-    return (setLockedCoins.count(outpt) > 0);
+    return setLockedCoins.count(output) > 0;
 }
 
 void CWallet::ListLockedCoins(std::vector<COutPoint>& vOutpts) const
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 7da601c3b7..a75b6981e1 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -441,16 +441,16 @@ public:
     //! check whether we support the named feature
     bool CanSupportFeature(enum WalletFeature wf) const override EXCLUSIVE_LOCKS_REQUIRED(cs_wallet) { AssertLockHeld(cs_wallet); return IsFeatureSupported(nWalletVersion, wf); }
 
-    bool IsSpent(const uint256& hash, unsigned int n) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    bool IsSpent(const COutPoint& outpoint) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
-    // Whether this or any known UTXO with the same single key has been spent.
-    bool IsSpentKey(const uint256& hash, unsigned int n) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    // Whether this or any known scriptPubKey with the same single key has been spent.
+    bool IsSpentKey(const CScript& scriptPubKey) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void SetSpentKeyState(WalletBatch& batch, const uint256& hash, unsigned int n, bool used, std::set<CTxDestination>& tx_destinations) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /** Display address on an external signer. Returns false if external signer support is not compiled */
     bool DisplayAddress(const CTxDestination& dest) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
-    bool IsLockedCoin(uint256 hash, unsigned int n) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    bool IsLockedCoin(const COutPoint& output) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool LockCoin(const COutPoint& output, WalletBatch* batch = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool UnlockCoin(const COutPoint& output, WalletBatch* batch = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool UnlockAllCoins() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);