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?
}
        m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
        LogPrintf("keypool reserve %d\n", nIndex);
    }
    return true;
}
void CWallet::KeepKey(int64_t nIndex)
{
    
    WalletBatch batch(*database);
    batch.ErasePool(nIndex);
    LogPrintf("keypool keep %d\n", nIndex);
}
void CWallet::ReturnKey(int64_t nIndex, bool fInternal, const CPubKey& pubkey)
{
    
    {
        LOCK(cs_wallet);
        if (fInternal) {
            setInternalKeyPool.insert(nIndex);
        } else if (!set_pre_split_keypool.empty()) {
            set_pre_split_keypool.insert(nIndex);
        } else {
            setExternalKeyPool.insert(nIndex);
        }
        m_pool_key_to_index[pubkey.GetID()] = nIndex;
    }
    LogPrintf("keypool return %d\n", nIndex);
}
bool CWallet::GetKeyFromPool(CPubKey& result, bool internal)