bug#33257: 26.1; Emacs 26.1 crashes with SEGFAULT under markdown-mode while opening large file

[Eli Zaretskii]

> From: Dennis Mayr <dennis.mayr.c@gmail.com>
> Date: Sun, 4 Nov 2018 14:21:54 -0300
> 
> Emacs + Spacemacs user here.
> 
> Since this week, when opening a large Markdown file, Emacs crashes
> with segfault. At best, it freezes and does not respond to anything
> but to `killall emacs26` (asking to save desktop).
> 
> This is the file:
> https://pastebin.com/YZygPNTk
> 
> *gdb* result:
> 
> ```
> Thread 1 "emacs26" received signal SIGSEGV, Segmentation fault.
> 0x00000000005dbe78 in ?? ()
> ```
> 
> No backtrace available.

It doesn't crash here, ad without the backtrace it's hard to do
anything with this.

Can you try building the latest emacs-26 branch of the Emacs Git
repository, and see if the problem happens there as well?

Failing that, we'd need a backtrace to start looking into this.
Perhaps download and install debug data package for your Emacs
distribution, or build yourself without stripping the binary.  Then
repeat the recipe under GDB.

Thanks.