Comment 19 for bug 263211

That commit has the following ChangeLog entry:

 * src/
 * src/
 * src/gs-manager.c (gs_manager_init),
 (apply_background_prefs_to_window), (manager_show_window):
 * src/gs-window-x11.c (gs_window_set_background_pixmap),
 (gs_window_clear_to_background_pixmap), (gs_window_clear),
 (spawn_on_window), (popup_dialog_idle), (gs_window_init):
 * src/gs-window.h:
 Add support for showing the desktop background behind the
 unlock dialog. Add dep on gnome-desktop and
 pull in libbackground as an svn:external.
 Still to-do:
 1. add bg_preferences_load_defaults to pull from
 system defaults instead of user settings
 2. process bg changes
 3. fix clearing child windows to the pixmap