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

[Duncan Bayne]

Eli Zaretskii <eliz@gnu.org> writes:

> [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?
>
> [2. application/octet-stream; known-hosts]...

Ah, that could be the problem.  My system fonts can't display any of
those emoji - they display as "tofu" after the 1.5 minutes.

What font are you using?  I'll install it and try to reproduce the issue
again.

--
Duncan Bayne
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