[gnome-shell] shell-screenshot: Fix cursor fetching for non single window screenshots

[Adel Gadllah <agadllah src gnome org>]

commit cdc4f85e478f2bf59dcffe1a1449af54b9086381
Author: Adel Gadllah <adel gadllah gmail com>
Date:   Sun Feb 10 14:18:54 2013 +0100

    shell-screenshot: Fix cursor fetching for non single window screenshots
    
    We have to mark the cairo_surface dirty after modifying the data behind
    cairo's back.
    
    Also use CAIRO_FORMAT_ARGB32 rather then CAIRO_FORMAT_RGB24 for the
    surface to be consistent with the rest of the code.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=691715

 src/shell-screenshot.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/src/shell-screenshot.c b/src/shell-screenshot.c
index 2914e07..da75ce0 100644
--- a/src/shell-screenshot.c
+++ b/src/shell-screenshot.c
@@ -217,7 +217,7 @@ do_grab_screenshot (_screenshot_data *screenshot_data,
   backend = clutter_get_default_backend ();
   context = clutter_backend_get_cogl_context (backend);
 
-  screenshot_data->image = cairo_image_surface_create (CAIRO_FORMAT_RGB24,
+  screenshot_data->image = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
                                                        width, height);
 
 
@@ -234,6 +234,8 @@ do_grab_screenshot (_screenshot_data *screenshot_data,
                                             x, y,
                                             COGL_READ_PIXELS_COLOR_BUFFER,
                                             bitmap);
+
+  cairo_surface_mark_dirty (screenshot_data->image);
   cogl_object_unref (bitmap);
 }