bug#71454: 30.0.50; Performance issues with font selection

[Eli Zaretskii]

> Cc: 71454@debbugs.gnu.org
> From: Kai Ma <justksqsf@gmail.com>
> Date: Mon, 10 Jun 2024 00:17:55 +0200
> 
> 
> > On Jun 10, 2024, at 00:10, Jeremy Bryant <jb@jeremybryant.net> wrote:
> > 
> > Would you be able to provide a self-contained series of steps starting
> > from emacs -Q?
> 
> On my machine it is extremely easy to reproduce by simply:
> 
> 1. emacs -Q
> 2. Switch to *scratch*
> 3. Copy the provided text into *scratch*
> 4. Emacs will freeze for 17 seconds or so, and it cannot be interrupted by C-g

I cannot reproduce this, I get an almost instantaneous redisplay with
those characters.

When your Emacs eventually displays the text, how many characters are
shown as boxes with hex code, and which ones are those?