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?
std::set<uint256> GetConflicts(const uint256& txid) const;
    
    bool HasWalletSpend(const uint256& txid) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    
    void Flush(bool shutdown=false);
    
    boost::signals2::signal<void ()> NotifyUnload;
    /**
     * Address book entry changed.
     * @note called with lock cs_wallet held.
     */
    boost::signals2::signal<void (CWallet *wallet, const CTxDestination
            &address, const std::string &label, bool isMine,
            const std::string &purpose,
            ChangeType status)> NotifyAddressBookChanged;
    /**
     * Wallet transaction added, removed or updated.
     * @note called with lock cs_wallet held.
     */
    boost::signals2::signal<void (CWallet *wallet, const uint256 &hashTx,
            ChangeType status)> NotifyTransactionChanged;
    
    boost::signals2::signal<void (const std::string &title, int nProgress)> ShowProgress;
    
    boost::signals2::signal<void (bool fHaveWatchOnly)> NotifyWatchonlyChanged;
    
    bool GetBroadcastTransactions() const { return fBroadcastTransactions; }