Merge lp:~raof/unity-greeter/fix-login-corruption into lp:unity-greeter

[Chris Halse Rogers]

Fix the corruption between unity-greeter and Unity loading (bug #931967)

This was caused by the root-window backing pixmap code being a smoking pile of
only-accidentally-works on Intel, and uses-uninitialised-VRAM on everything else.

[Robert Ancell (robert-ancell)]

review: Approve

=== modified file 'src/unity-greeter.vala'
--- src/unity-greeter.vala	2012-03-13 14:00:28 +0000
+++ src/unity-greeter.vala	2012-03-20 07:20:22 +0000
@@ -39,7 +39,7 @@
     private File state_file;
     private KeyFile state;
 
-    private static Cairo.Surface background_surface;
+    private static Cairo.XlibSurface background_surface;
 
     private SettingsDaemon settings_daemon;
 
@@ -402,9 +402,9 @@
     {
         /* Set the background */
         var c = new Cairo.Context (background_surface);
-        user_list.background.draw (c);
+        user_list.background.draw_full (c, Background.DrawFlags.NONE);
         c = null;
-        refresh_background (Gdk.Screen.get_default ());
+        refresh_background (Gdk.Screen.get_default (), background_surface);
 
         try
         {
@@ -439,6 +439,12 @@
                 }
                 else
                 {
+                    /* Set the background */
+                    var c = new Cairo.Context (background_surface);
+                    user_list.background.draw_full (c, Background.DrawFlags.NONE);
+                    c = null;
+                    refresh_background (Gdk.Screen.get_default (), background_surface);
+
                     debug ("Successfully logged in!  Quitting...");
                     Gtk.main_quit ();
                 }
@@ -694,19 +700,12 @@
         root.add_filter ((Gdk.FilterFunc) focus_upon_map);
     }
 
-    private static Cairo.Surface? create_root_surface (Gdk.Screen screen)
+    private static Cairo.XlibSurface? create_root_surface (Gdk.Screen screen)
     {
         var visual = screen.get_system_visual ();
 
-        /* Open a new connection so with Retain Permanent so the pixmap remains when the greeter quits */
-        Gdk.flush ();
-        var display = new X.Display (screen.get_display ().get_name ());
-        if (display == null)
-        {
-            warning ("Failed to create root pixmap");
-            return null;
-        }
-        display.set_close_down_mode (X.RetainPermanent);
+        unowned X.Display display = Gdk.X11Display.get_xdisplay (screen.get_display ());
+
         var pixmap = X.CreatePixmap (display,
                                      Gdk.X11Window.get_xid (screen.get_root_window ()),
                                      screen.width (),
@@ -714,25 +713,28 @@
                                      visual.get_depth ());
 
         /* Convert into a Cairo surface */
-        unowned X.Display xdisplay = Gdk.X11Display.get_xdisplay (screen.get_display ());
-        var surface = new Cairo.XlibSurface (xdisplay,
+        var surface = new Cairo.XlibSurface (display,
                                              pixmap,
                                              Gdk.X11Visual.get_xvisual (visual),
                                              screen.width (), screen.height ());
 
+        return surface;  
+    }
+
+    private void refresh_background (Gdk.Screen screen, Cairo.XlibSurface surface)
+    {
+        Gdk.flush ();
+
+        unowned X.Display display = Gdk.X11Display.get_xdisplay (screen.get_display ());
+
+        /* Ensure Cairo has actually finished its drawing */
+        surface.flush ();
         /* Use this pixmap for the background */
-        X.SetWindowBackgroundPixmap (xdisplay,
+        X.SetWindowBackgroundPixmap (display,
                                      Gdk.X11Window.get_xid (screen.get_root_window ()),
                                      surface.get_drawable ());
 
-
-        return surface;  
-    }
-
-    private void refresh_background (Gdk.Screen screen)
-    {
-        Gdk.flush ();
-        X.ClearWindow (Gdk.X11Display.get_xdisplay (screen.get_display ()), Gdk.X11Window.get_xid (screen.get_root_window ()));
+        X.ClearWindow (display, Gdk.X11Window.get_xid (screen.get_root_window ()));
     }
 
     private static void log_cb (string? log_domain, LogLevelFlags log_level, string message)