bug#63790: 30.0.50; prog-fill-reindent-defun regression

[Dmitry Gutov <dmitry@gutov.dev>]

On 04/06/2023 20:14, Juri Linkov wrote:
>>> This regression is in master, not in emacs-29.
>> If it is a regression, then compared to what? emacs-29 doesn't have this
>> function. Compared to some earlier revision?
> Sorry, the subject was not precise.  This is more elaborate:
> the new function 'prog-fill-reindent-defun' caused a regression for
> 'M-q' compared to emacs-29 where 'M-q' was bound to 'fill-paragraph'.

Thanks for the clarification.

>>> 0. emacs-30 -Q
>>> 1. add to the beginning of the*scratch*  buffer a list, so that
>>> *scratch*  looks like this:
>>> (+
>>>    1
>>>       2
>>>    3)
>>> ;; This buffer is for text that is not saved, and for Lisp evaluation.
>>> ;; To create a file, visit it with C-x C-f and enter text in its buffer.
>>> 2. Activate the region with the beginning at the start of the line with
>>> the first comment, and the region end with point at the end of the buffer.
>>> 3. Type 'M-q' (prog-fill-reindent-defun)
>>> It indents the list instead of the comment.
>>> But when point is at the region beginning then 'M-q' correctly indents
>>> the comments.
>> This happens because in this scenario point ends up outside of the comment
>> (at eob). So when the function is called, in looks for a defun.
>>
>> Did we at some point add (or decide to add) a condition when, if a region
>> is active, it should only refill and not reindent?
> Maybe the logic of region detecting/handling could be copied from
> 'fill-paragraph' to 'prog-fill-reindent-defun'?

Makes sense. Do you want to suggest a patch?