bug#74337: 29.4; Visiting a file with Unicode emojis is very slow

[Eli Zaretskii]

[Please use Reply All to reply, to keep the bug tracker CC'ed.]

> From: Duncan Bayne <duncan@bayne.id.au>
> Date: Thu, 14 Nov 2024 07:15:09 +1100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> From: Duncan Bayne <duncan@bayne.id.au>
> >> Date: Wed, 13 Nov 2024 23:13:26 +1100
> >>
> >> It takes ~ 1.5 minutes to visit even a small file containing Unicode
> >> emojis, and CPU utilization goes to 100% (of a single core) while it is
> >> loading.
> >>
> >> Reproduction steps:
> >>
> >> 1. Open Emacs with `emacs -Q`.
> >> 2. Visit the attached file (known-hosts).
> >> 3. Observe that it takes > 1 minute to visit the file.
> >
> > You haven't attached the file, please post it.
> >
> > Thanks.
> 
> Argh, sorry :/  Attached this time.

I'm attaching it also, to let the bug tracker and others to see it.

I cannot reproduce the problem on my system (which is not
amd64-portbld-freebsd): the file displays almost immediately for me.

Do emoji display as "tofu" (i.e. rectangular boxes with hex codepoint
value) on your system, after those 1.5 minutes, or do they display as
emoticons?  IOW, do you have on your system fonts that can display
emoji?

known-hosts
Description: Binary data