Subject: bug#26333: 26.0.50; Hang when displaying some special characters for the first time

From: Lars Ingebrigtsen <[email-masked]>
Date: Sun, 23 Jan 2022 17:17:15 +0100

Steven Allen <[email-masked]> writes:

> 1. Start `emacs -Q` (GUI mode, GTK3).
> 2. Open a scratch buffer.
> 3. Insert a MATHMATICAL SANS-SERIF BOLD SMALL LAMBDA (0x1D77A): 𝝺
>
> The first time this character is displayed, Emacs hangs for ~15 seconds
> pegging the CPU at 100%. Unfortunately, the profiler doesn't seem to
> notice/record this hang.

(I'm going through old bug reports that unfortunately weren't resolved
at the time.)

I'm unable to reproduce this problem in Emacs 28, but then again, this
problem seems to rely on a particular set of fonts being installed.

Are you still seeing the problem in recent Emacs versions?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no