wallet: unify FindNonChangeParentOutput functions

The function is only used in ListCoins.

Author: furszy

src/wallet/spend.cpp

@@ -362,30 +362,26 @@ CAmount GetAvailableBalance(const CWallet& wallet, const CCoinControl* coinContr
     return AvailableCoins(wallet, coinControl).GetTotalAmount();
 }
 
-const CTxOut& FindNonChangeParentOutput(const CWallet& wallet, const CTransaction& tx, int output)
+const CTxOut& FindNonChangeParentOutput(const CWallet& wallet, const COutPoint& outpoint)
 {
     AssertLockHeld(wallet.cs_wallet);
-    const CTransaction* ptx = &tx;
-    int n = output;
+    const CWalletTx* wtx{Assert(wallet.GetWalletTx(outpoint.hash))};
+
+    const CTransaction* ptx = wtx->tx.get();
+    int n = outpoint.n;
     while (OutputIsChange(wallet, ptx->vout[n]) && ptx->vin.size() > 0) {
         const COutPoint& prevout = ptx->vin[0].prevout;
-        auto it = wallet.mapWallet.find(prevout.hash);
-        if (it == wallet.mapWallet.end() || it->second.tx->vout.size() <= prevout.n ||
-            !wallet.IsMine(it->second.tx->vout[prevout.n])) {
+        const CWalletTx* it = wallet.GetWalletTx(prevout.hash);
+        if (!it || it->tx->vout.size() <= prevout.n ||
+            !wallet.IsMine(it->tx->vout[prevout.n])) {
             break;
         }
-        ptx = it->second.tx.get();
+        ptx = it->tx.get();
         n = prevout.n;
     }
     return ptx->vout[n];
 }
 
-const CTxOut& FindNonChangeParentOutput(const CWallet& wallet, const COutPoint& outpoint)
-{
-    AssertLockHeld(wallet.cs_wallet);
-    return FindNonChangeParentOutput(wallet, *wallet.GetWalletTx(outpoint.hash)->tx, outpoint.n);
-}
-
 std::map<CTxDestination, std::vector<COutput>> ListCoins(const CWallet& wallet)
 {
     AssertLockHeld(wallet.cs_wallet);

src/wallet/spend.h

@@ -99,7 +99,6 @@ CAmount GetAvailableBalance(const CWallet& wallet, const CCoinControl* coinContr
 /**
  * Find non-change parent output.
  */
-const CTxOut& FindNonChangeParentOutput(const CWallet& wallet, const CTransaction& tx, int output) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
 const CTxOut& FindNonChangeParentOutput(const CWallet& wallet, const COutPoint& outpoint) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
 
 /**