Gerd Möllmann <gerd.moellmann@gmail.com> writes:

> martin rudalics <rudalics@gmx.at> writes:
>
>>> So I guess I'm missing something important. Any ideas?
>>
>> Not really: I do the same but positioned the yellow frame more to the
>> left so that it is not obscured by the other two child frames.  Both
>> tty-child-frames.el ("/home/martin/temp/tm.el" is my location of your
>> tm.el) and my patch are attached.  I also attach a screenshot
>> immediately before clicking on the Buffer menu.  A complete transcript
>> of the debugging session is below.
>
> So, I think I have now exactly what you are using, and I eventually
> got a segfault somehow, and found out something:
>
> The root frame ended up containing glyphs from a dead menu frame. The
> dead frame's face cache was set to NULL because it had been freed. The
> series of events leading to this is still unclear to me. At least we
> never copy glyphs from a dead frame, that much I can say.
>
> Doesn't look like the assertion you are seeing, but maybe it's somehow
> related.
>
> More in the next round.

Could you please give this a try, Martin?