MEGALINTER_FILES_TO_LINT variable doesn't work as expected

[kcfedun-fincad]

Describe the bug

When calling the mega-linter-runner from the CLI and passing a list of files as positional arguments, these files get joined by the mega-linter-runner/lib/runner.js at https://github.com/oxsecurity/megalinter/blob/main/mega-linter-runner/lib/runner.js#L154. This results in the following being passed to the docker run command: -e MEGALINTER_FILES_TO_LINT=".mega-linter.yml,.pre-commit-config.yaml,app.py".

Expected behaviour

The expectation is that megalinter will run its checks against the list of files passed into it.

Actual behaviour

Megalinter only runs it's checks against .pre-commit-config.yaml (in this example), and throws the following warning messages:

[File listing] Input file /tmp/lint/".mega-linter.yml not found
[File listing] Input file /tmp/lint/app.py" not found

Notice the first warning is due to the first filename being pre-pended with a ", and the second is due to the filename appended with a ". This is cause by the creating of the env var at https://github.com/oxsecurity/megalinter/blob/main/mega-linter-runner/lib/runner.js#L154 and/or the unpacking of the list at https://github.com/oxsecurity/megalinter/blob/main/megalinter/config.py#L136.

To Reproduce

I discovered this when trying to run megalint via a pre-commit hook with the pass_filenames argument set at true. Pre-commit passes the list of stages files as a list of positional arguments to the command being called.

One can easily reproduce this issue by running something similar to npx -- mega-linter-runner --remove-container --flavor python --fix file1.py file2.py file3.py

[Kurt-von-Laven]

This is a very helpful and greatly appreciated duplicate of #1942 that adds a lot of clarity. I'm closing this simply for the sake of bookkeeping, but will continue the discussion on the original issue when I get a chance.