Subject: GUI (X) Emacs 26.1 locks up when '(' character is entered into a comment in (C/*l Abbrev) mode
From: James Vaughan <[email-masked]>
To: [email-masked]
Date: Sat, 17 Nov 2018 17:04:38 -0500
List-Id: <debbugs-submit.debbugs.gnu.org>

Reproduction
These are the precise steps I took, using this code
<https://gitlab.com/jvaughan/bpm.c> @
b6e7e4a6462644d83642ef2b1fae0a937c2fb339 :
1. With working directory in 'bpm.c/', start GUI Emacs in the background
with `emacs &`
2. Enter `C-x 3` to get vertical split, click into the right window, and
enter `C-x 2`.
3. From there, `M-x shell` to get a shell (zsh) in the bottom right corner.
4. Click into top right corner, `C-x C-f inc/parser.h`
5. Click into left half, `C-x C-f src/parser.c`
6. Append `// Continue checking if line is a comment (`.
Emacs will hang, not showing `(` or responding to clicks, commands, or GUI
interaction.
I had to `kill -9` it to get rid of it completely.
ps -a shows stat of emacs as RNl

$ uname -a
Linux workstation 4.19.1-arch1-1-ARCH #1 SMP PREEMPT Sun Nov 4 16:49:26 UTC
2018 x86_64 GNU/Linux

Thank you for looking into this.