bug#63956: 29.0.91; tex-mode display problem in emacs-29

[Eli Zaretskii <eliz@gnu.org>]

> From: Jeff Norden <norden.jeff@gmail.com>
> Date: Wed, 7 Jun 2023 12:52:10 -0500
> 
> I've been trying out the 2nd emacs-29 pretest.  It seems great.
> I haven't needed to tweak a single line of my .emacs or any of the
> custom files it loads (about 1200 lines in all).  The new
> 'with-restriction' feature may simplify a project that I've been
> playing with for a while.
> 
> However, I have found a minor issue with a change made to tex-mode.
> The simple calls to `display-buffer' in tex-mode.el have been replaced
> with:
>     (display-buffer tex-shell display-comint-buffer-action)
> The default value for display-comint-buffer-action is set from
> display-buffer--same-window-action.
> 
> As a result, the default behavior of `tex-buffer' or `tex-region' is
> that the document you are editing *disappears*, and and the window it
> was displayed in shows just the error messages (or lack thereof) from
> running TeX.  You then need to switch back to the document's buffer to
> continue editing.  This behavior makes no sense.  It would be
> equivalent to running `compile' on a C file, and then only seeing the
> output from make/gcc/etc, with the source code hidden.  The correct
> behavior in both cases is to show the process output in a window
> alongside the source.  Anyone who has been using tex-mode for years
> would certainly find this new behavior disruptive, although it is
> easily corrected.
> 
> I'm not sure if the `display-buffer' calls in tex-mode.el need to have
> an action argument, but if they do, it should be similar to what is
> used in compile.el.  I'll be the first to admit that I'm not
> particularly well-versed in the current intricacies of buffer display
> actions (nor do I have any real desire to become so :-).

Adding Sam, who made these changes in tex-mode.el.  Sam, any comments?

Jeff, would you please look at the 3 places in tex-mode where
display-comint-buffer-action was added to calls to pop-to-buffer and
display-buffer, and tell in which ones showing the buffer in the same
window by default makes sense?  I don't myself use tex-mode, so it is
hard for me to tell.  We could then discuss whether to remove the
argument in some of the cases or make a tex-mode-specific user option
to let users control that.  For example, in the specific case of
tex-display-shell it sounds like just dropping the argument would be
TRT, since all of its callers want to show the shell buffer, but not
in the selected window.  What about the other two cases where this
argument was added?

Thanks.