IOS : Uncaught error response during replace

[Atroskelis]

Caught this when trying to commit replace an altered post-grab get_config 'startup' which adds an unsupported line on line 1

 head config.txt 
  
Using 1316 out of 196600 bytes
!
! Last configuration change at 15:49:05 BUC Wed Feb 14 2018 by root
version 15.1
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname NAPALM-TARGET
!

Cisco 1841 Version 12.4(13r)t issues the following when doing

replace flash:candidate_config.txt force revert trigger error

The response is

%The input file is not a valid config file.

Napalm goes forward with the code, even if changes are not applied on the router. I may not be that good at Python, but i assume this code bit does not have this answer in order to raise exception

            if self.auto_rollback_on_error:
                cmd = 'configure replace {} force revert trigger error'.format(cfg_file)
            else:
                cmd = 'configure replace {} force'.format(cfg_file)
            output = self._commit_hostname_handler⌘
            if ('original configuration has been successfully restored' in output) or \
               ('error' in output.lower()) or \
               ('failed' in output.lower()):
                msg = "Candidate config could not be applied\n{}".format(output)
                raise ReplaceConfigException(msg)

Could we add this text to the code?