Merge #16322: wallet: Fix -maxtxfee check by moving it to CWallet::CreateTransaction

0d101a340c44841cbbc5982d55354b1787bc39e2 test: Add test for maxtxfee option (MarcoFalke)
177550101b600ccb32886695326eb72cd9752c8b wallet: Remove unreachable code in CreateTransaction (MarcoFalke)
5c1b9714cb0a13be28324f91f4ec9ca66a1de8c7 wallet: Fix -maxtxfee check by moving it to CWallet::CreateTransaction (João Barbosa)

Pull request description:

  Follow up to #16257, this PR makes `bumpfee` aware of `-maxtxfee`.

  It also prevents dangling locked unspents when calling `fundrawtransaction` - because the previous check was after `LockCoin`.

ACKs for top commit:
  MarcoFalke:
    re-ACK 0d101a340c44841cbbc5982d55354b1787bc39e2, only change is small test fixup

Tree-SHA512: 3464b24ae7cd4e72ed41438c6661828ba1304af020f05da62720b23668ae734e16cf47c6d97e150cc84ef631ee099b16fc786c858f3d089905845437338fd512

2 files changed, 10 insertions, 15 deletions

diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index c1b798bad6..57406179f7 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -221,9 +221,12 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
             return TransactionCreationFailed;
         }
 
-        // Reject absurdly high fee
-        if (nFeeRequired > m_wallet->getDefaultMaxTxFee())
+        // Reject absurdly high fee. (This can never happen because the
+        // wallet never creates transactions with fee greater than
+        // m_default_max_tx_fee. This merely a belt-and-suspenders check).
+        if (nFeeRequired > m_wallet->getDefaultMaxTxFee()) {
             return AbsurdFee;
+        }
     }
 
     return SendCoinsReturn(OK);
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index aedb22c31c..a9bd1e3164 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2696,11 +2696,6 @@ bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nC
         }
     }
 
-    if (nFeeRet > this->m_default_max_tx_fee) {
-        strFailReason = TransactionErrorString(TransactionError::MAX_FEE_EXCEEDED);
-        return false;
-    }
-
     return true;
 }
 
@@ -3010,14 +3005,6 @@ bool CWallet::CreateTransaction(interfaces::Chain::Lock& locked_chain, const std
                     return false;
                 }
 
-                // If we made it here and we aren't even able to meet the relay fee on the next pass, give up
-                // because we must be at the maximum allowed fee.
-                if (nFeeNeeded < chain().relayMinFee().GetFee(nBytes))
-                {
-                    strFailReason = _("Transaction too large for fee policy");
-                    return false;
-                }
-
                 if (nFeeRet >= nFeeNeeded) {
                     // Reduce fee to only the needed amount if possible. This
                     // prevents potential overpayment in fees if the coins
@@ -3134,6 +3121,11 @@ bool CWallet::CreateTransaction(interfaces::Chain::Lock& locked_chain, const std
         }
     }
 
+    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)) {