bug#28630: 27.0.50; C-g while a non-main thread is sitting crashes Emacs

[Eli Zaretskii]

> From: Alex <agrambot@gmail.com>
> Cc: eliz@gnu.org, Tom Tromey <tom@tromey.com>
> Date: Sat, 30 Sep 2017 21:18:08 -0600
> 
> Should this be labelled a blocker for Emacs 26?

Maybe I'm not sure.  It doesn't sound like threads are used much, if
at all, which would make blocking on it silly.

> This appears to be a related to bug 25214, since I just tried to hit
> C-g when running the example there and it indeed crashes Emacs.

Could be, but the problem in that bug is not a crash, it's the way the
code was written to work.

> It should be noted that `keyboard-escape-quit' (ESC ESC ESC) doesn't
> crash Emacs.

Most probably because it doesn't longjmp.

> Also, replacing (sit-for 2) with (read-char) or its family and hitting
> C-g will also crash Emacs.

Is your Emacs built with --enable-checking?  Because I get an
assertion violation in that case, not a crash.