Re: Redisplay issue

[Eli Zaretskii <eliz@gnu.org>]

> Date: Mon, 30 Nov 2015 20:51:15 -0800
> From: Yuan MEI <yuan.mei.list@gmail.com>
> Cc: emacs-devel <emacs-devel@gnu.org>
> 
> One more piece of information: once Emacs gets into `bad' mode,
> switching out of the virtual desktop then coming back in several times
> won't turn Emacs into `good' mode.  The way I used to recover was to
> switch to another Emacs buffer then switch back.  Also, it is
> interesting to see that a few seconds after seeing a completely blank
> `bad' Emacs frame, a few lines of glyphs show up.

Thanks.

Once again, the traces of handling the expose event are identical
between the "good" and the "bad" cases.

I have only one more idea: can you build Emacs without Cairo?  Cairo
changes the way Emacs draws the screen in significant ways, and that
is the only part of this puzzle that we didn't verify yet.  The traces
indicate that everything up to the point where we invoke the drawing
code is identical between the "good" and the "bad" cases, and
correctly instructs the display back-end to redraw every screen line
in the exposed region(s).