bug#44180: 28.0.50; Emacs frames won't redisplay unless resized

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Eric Abrahamsen <eric@ericabrahamsen.net>
>> Cc: rudalics@gmx.at,  44180@debbugs.gnu.org
>> Date: Sun, 25 Oct 2020 09:01:20 -0700
>> 
>> The problem is that switching focus between windows (frames) does not
>> update which window is "live". The most-recently created, or
>> most-recently resized, window is always the live one. If I switch focus
>> to one of the other frames, it doesn't update, and I need to move it
>> around somehow in order to make it live. Then the other frames go dead.
>> 
>> Before the breakage, it's possible that the non-visible frames were not
>> updated while they remained invisible, and I simply never knew because
>> I couldn't see them. Now they stay un-updated until I manipulate the
>> size of the window somehow.
>
> That seems to suggest that we don't trigger expose_frame calls anymore
> for the frames that become un-fontified?

I wouldn't know, but that certainly sounds likely. I'd be happy to try
contacting someone at i3, if that would be helpful, or to try fiddling
with the display code.