bug#45898: 27.1; wedged in redisplay again

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: gerd.moellmann@gmail.com,  larsi@gnus.org,  psainty@orcon.net.nz,
>   Emacs-hacker2018@jovi.net,  45898@debbugs.gnu.org
> Date: Fri, 01 Jul 2022 10:38:37 -0400
> 
> > In scan_sexps_forward, near the end: if too many "ticks" are counted,
> > update_redisplay_ticks will signal an error.  Same thing in
> > re_match_2_internal.
> 
> Ah... neat, thanks!
> Indeed, I can see the effect with:
> 
>     src/emacs -Q --eval '(setq syntax-wholeline-max most-positive-fixnum)' \
>                  --eval '(setq max-redisplay-ticks 100000)'                \
>                  ~/tmp/medium_line.json
> 
> in which case I get a warning about redisplay taking too long, whereas with:
> 
>     src/emacs -Q --eval '(setq max-redisplay-ticks 100000)' \
>                  ~/tmp/medium_line.json
> 
> I don't (because the `syntax-wholeline-max` keeps the font-lock time
> under control).

Good, so this change does have the expected effect.