bug#56561: 29.0.50; Infloop in try_window

[Eli Zaretskii]

> Cc: mwd@md5i.com, 56561@debbugs.gnu.org
> Date: Sat, 16 Jul 2022 10:32:30 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> > > The situation that started this bug report is one such case: my fix
> > > will cause try_window to return zero in that case.  But if the entire
> > > text was processed and is in the glyph matrix, that zero return value
> > > doesn't mean a failure.
> > 
> > That isn't what the comment above try_window says about its return
> > value:
> > 
> >    Value is 1 if successful.  It is zero if fonts were loaded during
> >    redisplay which makes re-adjusting glyph matrices necessary, and -1
> >    if point would appear in the scroll margins.
> >    (We check the former only if TRY_WINDOW_IGNORE_FONTS_CHANGE is
> >    unset in FLAGS, and the latter only if TRY_WINDOW_CHECK_MARGINS is
> >    set in FLAGS.)
> 
> I'm reading the code, not the commentary.  I will fix the commentary
> to be more accurate

Now done.