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

From: Eli Zaretskii <[email-masked]>
Date: Sat, 01 Apr 2017 23:44:58 +0300

> From: Steven Allen <[email-masked]>
> Date: Sat, 01 Apr 2017 12:20:35 -0700
> 
> 
> 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.

That's normal: Emacs is looking for a font that can display this
character.  If you install the Symbola font, I think the search will
be much faster.