In the log I see things like:

    2017-09-13 03:54:33 init message: Rescanning...
    2017-09-13 03:54:33 Rescanning last 68616 blocks (from block 416339)...
    2017-09-13 03:54:40 AddToWallet xxxxx  update
    2017-09-13 03:55:33 Still rescanning. At block 418849. Progress=0.549138

I would be interested to see the wallet file name on each of these log lines.

Would there be any interest in merging such a PR?
nOutput = i;
        }
    }
    if (nOutput == -1) {
        errors.push_back("Transaction does not have a change output");
        return Result::WALLET_ERROR;
    }
    
    int64_t txSize = GetVirtualTransactionSize(*(wtx.tx));
    const int64_t maxNewTxSize = CalculateMaximumSignedTxSize(*wtx.tx, wallet);
    if (maxNewTxSize < 0) {
        errors.push_back("Transaction contains inputs that cannot be signed");
        return Result::INVALID_ADDRESS_OR_KEY;
    }
    
    old_fee = wtx.GetDebit(ISMINE_SPENDABLE) - wtx.tx->GetValueOut();
    CFeeRate nOldFeeRate(old_fee, txSize);
    CFeeRate nNewFeeRate;
    
    
    
    CFeeRate walletIncrementalRelayFee = CFeeRate(WALLET_INCREMENTAL_RELAY_FEE);
    if (::incrementalRelayFee > walletIncrementalRelayFee) {
        walletIncrementalRelayFee = ::incrementalRelayFee;
    }
    if (total_fee > 0) {
        CAmount minTotalFee = nOldFeeRate.GetFee(maxNewTxSize) + ::incrementalRelayFee.GetFee(maxNewTxSize);
        if (total_fee < minTotalFee) {
            errors.push_back(strprintf("Insufficient totalFee, must be at least %s (oldFee %s + incrementalFee %s)",
                                                                FormatMoney(minTotalFee), FormatMoney(nOldFeeRate.GetFee(maxNewTxSize)), FormatMoney(::incrementalRelayFee.GetFee(maxNewTxSize))));