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?
throw JSONRPCError(RPC_INVALID_PARAMETER, "More than private key given for one address");
        }
        
        if (isP2SH && !IsHex(strRedeemScript)) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid redeem script");
        }
        
        
        if (isP2SH) {
            
            std::vector<unsigned char> vData(ParseHex(strRedeemScript));
            CScript redeemScript = CScript(vData.begin(), vData.end());
            
            if (!script.IsPayToScriptHash()) {
                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid P2SH address / script");
            }
            pwallet->MarkDirty();
            if (!pwallet->AddWatchOnly(redeemScript, timestamp)) {
                throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
            }
            CScriptID redeem_id(redeemScript);
            if (!pwallet->HaveCScript(redeem_id) && !pwallet->AddCScript(redeemScript)) {
                throw JSONRPCError(RPC_WALLET_ERROR, "Error adding p2sh redeemScript to wallet");
            }
            CScript redeemDestination = GetScriptForDestination(redeem_id);
            if (::IsMine(*pwallet, redeemDestination) == ISMINE_SPENDABLE) {
                throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already contains the private key for this address or script");
            }
            pwallet->MarkDirty();
            if (!pwallet->AddWatchOnly(redeemDestination, timestamp)) {