bug#67462: 30.0.50; prog-fill-reindent-defun does not respect buffer-local fill-paragraph-function

[Eli Zaretskii]

> From: Jens Schmidt <jschmidt4gnu@vodafonemail.de>
> Cc: 67462@debbugs.gnu.org,  dmitry@gutov.dev
> Date: Wed, 29 Nov 2023 22:28:49 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > So you are saying that indent-region doesn't do its job in some/many
> > major modes?  Can we fix that?  Or what am I missing now?
> 
> No, indent-region does a good job and there is nothing to fix here.  But
> starting with Emacs 30 it does that job (also) on M-q, where previously
> other functionality may have been bound.
> 
> To see the difference, please try executing in Emacs 29 vs master on
> Emacs's own, configured Makefile:
> 
>   ./src/emacs -Q Makefile --eval '(search-forward "SUBDIR_MAKEFILES_IN")'
>   M-q

So the problem is that the new code does its job, just with different
results than the mode-specific fill-paragraph-function did in Emacs 29
and before?  If so, perhaps we should offer a user option to let users
choose which method to use, because some might prefer the new
behavior?