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?
{
    
    if (IsCoinBase() && GetBlocksToMaturity() > 0)
        return 0;
    CAmount credit = 0;
    if (filter & ISMINE_SPENDABLE)
    {
        
        if (fCreditCached)
            credit += nCreditCached;
        else
        {
            nCreditCached = pwallet->GetCredit(*tx, ISMINE_SPENDABLE);
            fCreditCached = true;
            credit += nCreditCached;
        }
    }
    if (filter & ISMINE_WATCH_ONLY)
    {
        if (fWatchCreditCached)
            credit += nWatchCreditCached;