Do not modify files if parsing fails

[neuroid]

What does this do / why do we need it?

Consider the following example:

$ cat file
${UNDECLARED}
$ ep file
2024/03/05 21:33:31 [ ERROR ] 'file' requires undeclared environment variable 'UNDECLARED', no default is given
2024/03/05 21:33:31 [ ERROR ] Error while parsing 'file': 'file' requires undeclared environment variable 'UNDECLARED', no default is give
$ echo $?
1
$ cat file

$

I would expect the file to not be modified since the command resulted in an error.

How this PR fixes the problem?

The proposed change aborts writing the modified buffer if any errors occurred.

What should your reviewer look out for in this PR?

N/A

Check lists

• Test passed
• Coding style (indentation, etc)

Additional Comments (if any)

N/A

Which issue(s) does this PR fix?

N/A

[neuroid]

Hi @mavogel 👋 Is this something you would be interested in merging?

[enc]

I will have a look into the pipeline later. Thank you for reminding us.