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

[Eric Abrahamsen <eric@ericabrahamsen.net>]

On 10/25/20 17:08 PM, Eli Zaretskii wrote:
>> From: Eric Abrahamsen <eric@ericabrahamsen.net>
>> Cc: Eli Zaretskii <eliz@gnu.org>,  44180@debbugs.gnu.org
>> Date: Sat, 24 Oct 2020 13:19:45 -0700
>> 
>> Sorry if this wasn't clear. The window manager can display multiple
>> windows (our frames) tiled into some sort of grid, in which case
>> everything behaves correctly, or it can allow one of the windows to take
>> up the full workspace, and other windows are only visible as a sort of
>> window title bar, either tabbed along the top, or stacked along the top.
>> I'm attaching a screenshot, that's stacked.
>
> Since the other frames are not really visible, treating them as
> iconified makes some sense.  But then I don't understand your original
> report: you said these frames are not updated, but since they are
> obscured, what does "updated" mean for them?
>
> IOW, I'm now confused regarding the original report of the problem you
> have.  I guess we need to start from the beginning now, so I'm asking
> you to describe in more detail what doesn't work in this situation.

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.