bug#58771: 29.0.50; context submenu can not click when run emacs lucid build.

[Po Lu]

Feng Shu <tumashu@163.com> writes:

> just right click in emacs buffer.

I managed to reproduce a hang trying to click on the submenu item, but
then killed Emacs in an attempt to reproduce the problem again, and it
stopped happening.  Since that, I haven't been able to reproduce the
hang.

So it would be nice if you could try to find a way to reproduce this bug
from "emacs -Q", because I'm really lost.

Thanks in advance.