3 files changed, 26 insertions, 4 deletions
diff --git a/src/wallet/spend.cpp b/src/wallet/spend.cpp
index d6362c1f14..001acd04e2 100644
--- a/src/wallet/spend.cpp
+++ b/src/wallet/spend.cpp
@@ -569,8 +569,12 @@ std::optional<SelectionResult> SelectCoins(const CWallet& wallet, CoinsResult& a
             if (!coin_control.GetExternalOutput(outpoint, txout)) {
                 return std::nullopt;
             }
+        }
+
+        if (input_bytes == -1) {
             input_bytes = CalculateMaximumSignedInputSize(txout, outpoint, &coin_control.m_external_provider, &coin_control);
         }
+
         // If available, override calculated size with coin control specified size
         if (coin_control.HasInputWeight(outpoint)) {
             input_bytes = GetVirtualTransactionSize(coin_control.GetInputWeight(outpoint), 0, 0);
@@ -1127,12 +1131,16 @@ bool FundTransaction(CWallet& wallet, CMutableTransaction& tx, CAmount& nFeeRet,
     wallet.chain().findCoins(coins);
 
     for (const CTxIn& txin : tx.vin) {
-        // if it's not in the wallet and corresponding UTXO is found than select as external output
         const auto& outPoint = txin.prevout;
-        if (wallet.mapWallet.find(outPoint.hash) == wallet.mapWallet.end() && !coins[outPoint].out.IsNull()) {
-            coinControl.SelectExternal(outPoint, coins[outPoint].out);
-        } else {
+        if (wallet.IsMine(outPoint)) {
+            // The input was found in the wallet, so select as internal
             coinControl.Select(outPoint);
+        } else if (coins[outPoint].out.IsNull()) {
+            error = _("Unable to find UTXO for external input");
+            return false;
+        } else {
+            // The input was not in the wallet, but is in the UTXO set, so select as external
+            coinControl.SelectExternal(outPoint, coins[outPoint].out);
         }
     }
 
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index d598425326..45d2c3692d 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1428,6 +1428,19 @@ bool CWallet::IsMine(const CTransaction& tx) const
     return false;
 }
 
+isminetype CWallet::IsMine(const COutPoint& outpoint) const
+{
+    AssertLockHeld(cs_wallet);
+    auto wtx = GetWalletTx(outpoint.hash);
+    if (!wtx) {
+        return ISMINE_NO;
+    }
+    if (outpoint.n >= wtx->tx->vout.size()) {
+        return ISMINE_NO;
+    }
+    return IsMine(wtx->tx->vout[outpoint.n]);
+}
+
 bool CWallet::IsFromMe(const CTransaction& tx) const
 {
     return (GetDebit(tx, ISMINE_ALL) > 0);
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 4fc41b2f53..3a46d0a987 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -685,6 +685,7 @@ public:
     CAmount GetDebit(const CTxIn& txin, const isminefilter& filter) const;
     isminetype IsMine(const CTxOut& txout) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool IsMine(const CTransaction& tx) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    isminetype IsMine(const COutPoint& outpoint) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     /** should probably be renamed to IsRelevantToMe */
     bool IsFromMe(const CTransaction& tx) const;
     CAmount GetDebit(const CTransaction& tx, const isminefilter& filter) const;