bug#63959: python-mode does not keep indentation in square brackets []

[Eli Zaretskii]

> From: Konstantin Kharlamov <hi-angel@yandex.ru>
> Date: Thu, 08 Jun 2023 12:39:23 +0300
> 
> Usually in programming modes, when previous indentation is kind of "special",
> the new lines should keep the indentation from the previous line. However, it
> doesn't work in this case.
> 
> 
> # Steps to reproduce
> 
> 1. Create file `test.py` with following content:
> 
>     for infix in [ # some description
>                   "_cdata", "_cmeta", "_corig", "_cpool", "_cvol", "_wcorig",
>                   "indentation is broken here", "bar"]:
>         print(infix)
> 
> 2. Open it as `emacs -Q test.py`
> 3. Put a caret on the 3rd line (which says "indentation is broken"
> 4. Press TAB
> 
> 
> ## Expected
> 
> Indentation won't change
> 
> ## Actual
> 
> The line goes back by 4 spaces or so
> 
> # Additional information
> 
> emacs version: compiled from latest git a week ago, commit 5cace109d2b

kobarity, any comments?