[mutter] unset _NET_SUPPORTING_WM_CHECK when shutting down

[Owen Taylor <otaylor src gnome org>]

commit 11d0d207fd770fd297556904e4a458dc3308f311
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Jul 9 10:26:20 2009 -0400

    unset _NET_SUPPORTING_WM_CHECK when shutting down

 src/core/screen.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/src/core/screen.c b/src/core/screen.c
index 329035c..21b4663 100644
--- a/src/core/screen.c
+++ b/src/core/screen.c
@@ -264,6 +264,13 @@ set_wm_check_hint (MetaScreen *screen)
   return Success;
 }
 
+static void
+unset_wm_check_hint (MetaScreen *screen)
+{
+  XDeleteProperty (screen->display->xdisplay, screen->xroot, 
+                   screen->display->atom__NET_SUPPORTING_WM_CHECK);
+}
+
 static int
 set_supported_hint (MetaScreen *screen)
 {
@@ -850,6 +857,8 @@ meta_screen_free (MetaScreen *screen,
     meta_warning (_("Could not release screen %d on display \"%s\"\n"),
                   screen->number, screen->display->name);
 
+  unset_wm_check_hint (screen);
+
   XDestroyWindow (screen->display->xdisplay,
                   screen->wm_sn_selection_window);