[#3791] propose a fix

[rr-]

Steps

• Add yourself to CONTRIBUTORS if you are a new contributor.
• Add a ChangeLog entry describing what your PR does.
• If it's a new feature or an important bug fix, add a What's New entry in
  doc/whatsnew/<current release.rst>.
• Write a good description on what the PR does.

Description

This is a proposed fix for an issue where defining a function decorated with a list comprehension that shares argument name, and the argument is used twice in the list comprehension, it shows an undefined-variable error.

To put it in code:

def decorator(seq):
    return lambda f: f

@decorator(x * x for x in "123")
def func(x):
    pass

This wrongfully shows an undefined-variable error since version at least 2.7.

def decorator(seq):
    return lambda f: f

@decorator(x for x in "123")
def func(x):
   pass

This is rightfully OK on the current main.

This probably will need changes, but I am not familiar enough with the codebase to go better about it.

Type of Changes

	Type
✓	🐛 Bug fix

Related Issue

Closes #3791

[coveralls]

Coverage increased (+0.06%) to 92.154% when pulling d987fe0 on rr-:issue_3791 into 31aa6fd on PyCQA:main.

[Pierre-Sassoulas]

Look good thank you for the analysis, I have a small comment but this looks mergeable already.

[Pierre-Sassoulas]

I think it should be an or line 1012 instead :)

[rr-]

Thanks, moved

[Pierre-Sassoulas]

There's a modification here, I don't know why ;)

[rr-]

This is just a guess but I think my editor ate the byte order mark?

[rr-]

That was it. Restored :)

[Pierre-Sassoulas]

👍

[Pierre-Sassoulas]

Thank you for the fix and congratulation on becoming a pylint contributor :) !