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?
#ifndef BITCOIN_WALLET_WALLET_H
#define BITCOIN_WALLET_WALLET_H
#include <amount.h>
#include <outputtype.h>
#include <policy/feerate.h>
#include <streams.h>
#include <tinyformat.h>
#include <ui_interface.h>
#include <utilstrencodings.h>
#include <validationinterface.h>
#include <script/ismine.h>
#include <script/sign.h>
#include <util.h>
#include <wallet/crypter.h>
#include <wallet/coinselection.h>
#include <wallet/walletdb.h>