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

[martin rudalics <rudalics@gmx.at>]

 >> Do you get the corresponding focus events (whatever they are now) when
 >> you make another frame the fullscreen one?  If so, we should probably
 >> redraw the frame in that case.
 >
 > I'm still not at the offending computer, but I think there's a high
 > likelihood of confusing myself with conflicting terminology here so,
 > just to be clear: this isn't proper fullscreening in the X11 sense.

I didn't expect it to be but thanks for confirming.

 > i3
 > also does that, but I hardly ever use it since the stacked layout is
 > close enough to full screen. In X11 terms I think all that's happening
 > is switching of focus between windows, it's just that i3's layout means
 > that the unfocused windows are always completely obscured. For some
 > reason Emacs now thinks that a window being obscured means that it's now
 > an icon. Switching focus back to that window does not un-iconify it.

Always keep in mind that Emacs has no idea about whether and how a
window has been iconified or focused.  It just waits for the
corresponding information from the window manager, believes what the
latter tells and acts (redrawing a frame, for example) accordingly.

 > Anyway, more later in the day...

martin