Log when we use fee=0 for small inputs

src/wallet/asyncrpcoperation_sweep.cpp

@@ -197,9 +197,10 @@ bool AsyncRPCOperation_sweep::main_impl() {
 
             CAmount fee = fSweepTxFee;
             if (amountToSend <= fSweepTxFee) {
-              fee = 0;
+                LogPrintf("%s: Amount to send %s is <= fee, using fee=0", getId(), FormatMoney(amountToSend));
+                fee = 0;
             }
-            amountSwept += amountToSend;
+
             auto builder = TransactionBuilder(consensusParams, targetHeight_, pwalletMain);
             {
                 LOCK2(cs_main, pwalletMain->cs_wallet);