Subject: Re: bug#24662: 24.5; Markdown mode freezes Emacs when using TeX input method in a header

From: Eli Zaretskii <[email-masked]>
Date: Mon, 10 Oct 2016 22:03:31 +0300

> From: Christophe Troestler <[email-masked]>
> Date: Mon, 10 Oct 2016 20:02:52 +0200
> 
> Elpa Markdown mode makes Emacs use 100% CPU and be unresponsive (C-g has 
> no effect) when using TeX input method in a header followed by an URL.
> 
> Steps to reproduce:
> 
> - Run: emacs -q
> - Execute (if you are using Debian or derivatives and installed 
>   elpa-markdown-mode — otherwise see 
>   http://jblevins.org/projects/markdown-mode/):
> 
> (load
> "/usr/share/emacs/site-lisp/elpa-src/markdown-mode-2.1/markdown-mode.el")
> 
> - Create a file, say a.md, containing
> 
> #
> 
> http://
> 
> - Place the cursor after "#".
> 
> - Switch to TeX input method (C-\ and select TeX)
> 
> - Type \  (then Emacs freezes)

Thank you for your report.

I'm not sure why do you think it's an Emacs bug.  AFAICT, Emacs
infloops in font-lock routines set up by markdown-mode, so it could
well be a bug in markdown-mode itself.