From e15bc372255ac0954b22218a38427dde34c23118 Mon Sep 17 00:00:00 2001
From: Ray Strode <rstrode@redhat.com>
Date: Fri, 1 Mar 2013 14:41:11 -0500
Subject: [PATCH] compositor: map overlay window before redirecting windows

When windows get redirected off screen, all that gets left behind
is black. We don't want to flicker black at startup, though.

This commit maps the overlay window early, before redirecting
toplevels, so they end up getting snapshotted onto the background
pixmap of the overlay window when the overlay window is mapped.

https://bugzilla.gnome.org/show_bug.cgi?id=694321
---
 src/compositor/compositor.c | 47 ++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 16 deletions(-)

diff --git a/src/compositor/compositor.c b/src/compositor/compositor.c
index c5021ebbc..20cbde4c6 100644
--- a/src/compositor/compositor.c
+++ b/src/compositor/compositor.c
@@ -464,23 +464,16 @@ after_stage_paint (gpointer data)
   return TRUE;
 }
 
-void
-meta_compositor_manage_screen (MetaCompositor *compositor,
-                               MetaScreen     *screen)
+static void
+redirect_windows (MetaCompositor *compositor,
+                  MetaScreen     *screen)
 {
-  MetaCompScreen *info;
-  MetaDisplay    *display       = meta_screen_get_display (screen);
-  Display        *xdisplay      = meta_display_get_xdisplay (display);
-  int             screen_number = meta_screen_get_screen_number (screen);
-  Window          xroot         = meta_screen_get_xroot (screen);
-  Window          xwin;
-  gint            width, height;
-  guint           n_retries;
-  guint           max_retries;
-
-  /* Check if the screen is already managed */
-  if (meta_screen_get_compositor_data (screen))
-    return;
+  MetaDisplay *display       = meta_screen_get_display (screen);
+  Display     *xdisplay      = meta_display_get_xdisplay (display);
+  Window       xroot         = meta_screen_get_xroot (screen);
+  int          screen_number = meta_screen_get_screen_number (screen);
+  guint        n_retries;
+  guint        max_retries;
 
   if (meta_get_replace_current_wm ())
     max_retries = 5;
@@ -513,6 +506,21 @@ meta_compositor_manage_screen (MetaCompositor *compositor,
       n_retries++;
       g_usleep (G_USEC_PER_SEC);
     }
+}
+
+void
+meta_compositor_manage_screen (MetaCompositor *compositor,
+                               MetaScreen     *screen)
+{
+  MetaCompScreen *info;
+  MetaDisplay    *display       = meta_screen_get_display (screen);
+  Display        *xdisplay      = meta_display_get_xdisplay (display);
+  Window          xwin;
+  gint            width, height;
+
+  /* Check if the screen is already managed */
+  if (meta_screen_get_compositor_data (screen))
+    return;
 
   info = g_new0 (MetaCompScreen, 1);
   /*
@@ -611,6 +619,13 @@ meta_compositor_manage_screen (MetaCompositor *compositor,
     }
 
   clutter_actor_show (info->overlay_group);
+
+  /* Map overlay window before redirecting windows offscreen so we catch their
+   * contents until we show the stage.
+   */
+  XMapWindow (xdisplay, info->output);
+
+  redirect_windows (compositor, screen);
 }
 
 void