Random segfaults when using M-x.

[Zack Piper <zack@apertron.net>]

I get the following backtrace (seemingly at random) when pressing M-x,
this happens sometimes 2 times a day, I didn't report a bug because I
couldn't reproduce it reliably, but it randomly happened 2 times just
now when trying to debug what was happening (both times during trying
to use M-x). Shall I try disecting my Emacs configuration
(https://github.com/zackp30/dotfiles) or wait to see if that's not
needed and it's a known bug?

```
$ sed -n 's/.*\[\(.*\)]$/\1/p' backtrace | addr2line -C -f -i -p -e $(which emacs)
emacs_backtrace at /home/zack/emacs/src/sysdep.c:2188
terminate_due_to_signal at /home/zack/emacs/src/emacs.c:374
handle_fatal_signal at /home/zack/emacs/src/sysdep.c:1604
deliver_thread_signal.constprop.6 at
/home/zack/emacs/src/sysdep.c:1578
handle_sigsegv at /home/zack/emacs/src/sysdep.c:1654
?? ??:0
turn_on_face at /home/zack/emacs/src/term.c:1902 (discriminator 3)
tty_write_glyphs at /home/zack/emacs/src/term.c:777
update_frame_line at /home/zack/emacs/src/dispnew.c:4832
update_frame_1 at /home/zack/emacs/src/dispnew.c:4534
update_frame at /home/zack/emacs/src/dispnew.c:3123
redisplay_internal at /home/zack/emacs/src/xdisp.c:13786
(discriminator 2)
read_char at /home/zack/emacs/src/keyboard.c:2544
read_key_sequence at /home/zack/emacs/src/keyboard.c:9156
command_loop_1 at /home/zack/emacs/src/keyboard.c:1407
internal_condition_case at /home/zack/emacs/src/eval.c:1350
command_loop_2 at /home/zack/emacs/src/keyboard.c:1140 (discriminator
1)
internal_catch at /home/zack/emacs/src/eval.c:1110
command_loop at /home/zack/emacs/src/keyboard.c:1111
recursive_edit_1 at /home/zack/emacs/src/keyboard.c:729
XUNTAG at /home/zack/emacs/src/lisp.h:844
(inlined by) XWINDOW at /home/zack/emacs/src/lisp.h:1010
(inlined by) read_minibuf at /home/zack/emacs/src/minibuf.c:684
Fread_from_minibuffer at /home/zack/emacs/src/minibuf.c:970
Ffuncall at /home/zack/emacs/src/eval.c:2748
exec_byte_code at /home/zack/emacs/src/bytecode.c:919
funcall_lambda at /home/zack/emacs/src/eval.c:2951
backtrace_debug_on_exit at /home/zack/emacs/src/eval.c:159
(inlined by) Ffuncall at /home/zack/emacs/src/eval.c:2791
exec_byte_code at /home/zack/emacs/src/bytecode.c:919
funcall_lambda at /home/zack/emacs/src/eval.c:2951
backtrace_debug_on_exit at /home/zack/emacs/src/eval.c:159
(inlined by) Ffuncall at /home/zack/emacs/src/eval.c:2791
exec_byte_code at /home/zack/emacs/src/bytecode.c:919
funcall_lambda at /home/zack/emacs/src/eval.c:2951
backtrace_debug_on_exit at /home/zack/emacs/src/eval.c:159
(inlined by) Ffuncall at /home/zack/emacs/src/eval.c:2791
exec_byte_code at /home/zack/emacs/src/bytecode.c:919
funcall_lambda at /home/zack/emacs/src/eval.c:2951
backtrace_debug_on_exit at /home/zack/emacs/src/eval.c:159
(inlined by) Ffuncall at /home/zack/emacs/src/eval.c:2791
exec_byte_code at /home/zack/emacs/src/bytecode.c:919
funcall_lambda at /home/zack/emacs/src/eval.c:2951
backtrace_debug_on_exit at /home/zack/emacs/src/eval.c:159
(inlined by) Ffuncall at /home/zack/emacs/src/eval.c:2791
SPECPDL_INDEX at /home/zack/emacs/src/lisp.h:2998
(inlined by) Ffuncall_interactively at
/home/zack/emacs/src/callint.c:246
Ffuncall at /home/zack/emacs/src/eval.c:2698
Fapply at /home/zack/emacs/src/eval.c:2341
```

Thanks!

-- 
Zack Piper <zack@apertron.net> http://apertron.net