bug#61667: 29.0.60; Failure to redisplay

[Eli Zaretskii]

> Cc: 61667@debbugs.gnu.org
> Date: Tue, 21 Feb 2023 12:43:29 +0200
> From: Dmitry Gutov <dgutov@yandex.ru>
> 
> With --eval '(trace-redisplay t)', redisplay always happens. ;-(

That's strange: trace-redisplay just adds calls to functions that
write to stderr, but doesn't change the display code in any way that
could affect the control or data flow.  So, unless this is some weird
compiler bug, I don't understand how trace-redisplay could have
affected this.  Although the fact that with a tool bar displayed you
cannot reproduce the problem is already weird for the same reason.

If you build with no optimizations (CFLAGS=-O0 ./configure...), but
without --enable-checking=glyphs, does the problem still happen?

> That's not the effect of 'checking', though -- I can still repro if I 
> don't turn on redisplay tracing (which prints stuff in the background 
> window; maybe it's relevant, maybe it's not).

By "background window" you mean a shell window from which you started
Emacs?  Or do you mean something else?