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 (!bForceNew) {
        if (!account.vchPubKey.IsValid())
            bForceNew = true;
        else {
            
            CScript scriptPubKey = GetScriptForDestination(GetDestinationForKey(account.vchPubKey, m_default_address_type));
            for (std::map<uint256, CWalletTx>::iterator it = mapWallet.begin();
                 it != mapWallet.end() && account.vchPubKey.IsValid();
                 ++it)
                for (const CTxOut& txout : (*it).second.tx->vout)
                    if (txout.scriptPubKey == scriptPubKey) {
                        bForceNew = true;
                        break;
                    }
        }
    }
    
    if (bForceNew) {
        if (!GetKeyFromPool(account.vchPubKey, false))
            return false;
        LearnRelatedScripts(account.vchPubKey, m_default_address_type);
        dest = GetDestinationForKey(account.vchPubKey, m_default_address_type);
        SetAddressBook(dest, label, "receive");
        batch.WriteAccount(label, account);
    } else {
        dest = GetDestinationForKey(account.vchPubKey, m_default_address_type);
    }
    return true;
}
void CWallet::MarkDirty()