bug#73734: [PATCH] Fix tmm menu layout

[Eli Zaretskii <eliz@gnu.org>]

> From: Manuel Giraud <manuel@ledu-giraud.fr>
> Cc: rudalics@gmx.at,  73734@debbugs.gnu.org
> Date: Sat, 12 Oct 2024 16:10:10 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> [...]
> 
> > This doesn't align bindings if a variable-pitch font is used, but
> > it still produces a better display than the current code does when
> > variable-pitch font is the default font.
> 
> Thanks, yes this is better to remove the confusion (but sometimes misses
> bindings alignment).  To finalize this patch, I still have two questions
> left:
> 
>         - What is the purpose of the "(min 30)"?  Because if the window
>           is large enough this will always return 30.

First, I didn't write this code and don't consider myself an expert,
so what follows are basically my guesses.  (In the code I proposed I
simply didn't touch those parts to clearly separate my changes from
the rest.)

I think the minimum of 30 is there to make sure we don't produce just
2 sets of columns when the window is wide enough to allow more.  This
uses the screen real estate more efficiently, so the *Completions*
window is not as tall as it would be with just 2 sets of columns.

>         - Should we use frame-width instead of window-width?  It seems
>           that when this function is called (get-buffer-window
>           "*Completions*") always returns nil.

I think we should fall back to frame-width, but use the width of the
*Completions* window if it exists.  I'm quite sure there's a sequence
of commands which will leave the *Completions* buffer on display, and
in that case the window showing it will be reused.