[mutter] MetaWindowActor: don't unredirect ARGB32 windows

[Rui Matos <rtcm src gnome org>]

commit bf175e72ad80386ab0491b28f2f2d2fdfe806820
Author: Rui Matos <tiagomatos gmail com>
Date:   Tue Oct 18 00:52:14 2011 +0100

    MetaWindowActor: don't unredirect ARGB32 windows
    
    In particular this would a cause a "flash" when showing the tile preview for
    maximization on a non-primary monitor.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=662053

 src/compositor/meta-window-actor.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/compositor/meta-window-actor.c b/src/compositor/meta-window-actor.c
index f9e2ff8..5f79510 100644
--- a/src/compositor/meta-window-actor.c
+++ b/src/compositor/meta-window-actor.c
@@ -1217,8 +1217,9 @@ meta_window_actor_should_unredirect (MetaWindowActor *self)
 {
   MetaWindow *metaWindow = meta_window_actor_get_meta_window (self);
   MetaScreen *screen = meta_window_get_screen (metaWindow);
+  MetaWindowActorPrivate *priv = self->priv;
 
-  if (meta_window_is_override_redirect (metaWindow) && self->priv->opacity == 0xff)
+  if (meta_window_is_override_redirect (metaWindow) && priv->opacity == 0xff && !priv->argb32)
     {
       int screen_width, screen_height;
       MetaRectangle window_rect;