The following patch, based on the patch submitted at
https://bugzilla.redhat.com/show_bug.cgi?id=562143#c2 addresses a file handle
leak issue in GDM.  After about 6 weeks of operation, it appears that gdm
crashes due to code not releasing file handles properly and thus leading to a
"too many open files" error message in the log:

Sep 20 08:23:24 cgmv1 gdm-binary[31050]: CRITICAL: could not add display to access file: Too many open files
Sep 20 08:23:24 cgmv1 gdm-binary[31050]: WARNING: Unable to set up access control for display 1691
Sep 20 08:23:24 cgmv1 gdm-binary[31050]: WARNING: GdmDisplay: display lasted 0.010734 seconds

The result is that new clients are unable to connect.  The only way to fix the
issue otherwise is to re-start gdm, which terminates all active connections.

--- gdm-2.30.2.is.2.30.0/daemon/gdm-xdmcp-greeter-display.c.orig	2012-09-20 13:03:50.694403867 +1000
+++ gdm-2.30.2.is.2.30.0/daemon/gdm-xdmcp-greeter-display.c	2012-09-20 13:10:39.866405419 +1000
@@ -59,6 +59,7 @@
 static void     gdm_xdmcp_greeter_display_class_init    (GdmXdmcpGreeterDisplayClass *klass);
 static void     gdm_xdmcp_greeter_display_init          (GdmXdmcpGreeterDisplay      *xdmcp_greeter_display);
 static void     gdm_xdmcp_greeter_display_finalize      (GObject                     *object);
+static gboolean gdm_xdmcp_greeter_display_finish        (GdmDisplay                  *display);
 
 G_DEFINE_TYPE (GdmXdmcpGreeterDisplay, gdm_xdmcp_greeter_display, GDM_TYPE_XDMCP_DISPLAY)
 
@@ -66,8 +67,10 @@
 gdm_xdmcp_greeter_display_class_init (GdmXdmcpGreeterDisplayClass *klass)
 {
         GObjectClass    *object_class = G_OBJECT_CLASS (klass);
+        GdmDisplayClass *display_class = GDM_DISPLAY_CLASS (klass);
 
         object_class->finalize = gdm_xdmcp_greeter_display_finalize;
+        display_class->finish = gdm_xdmcp_greeter_display_finish;
 
         g_type_class_add_private (klass, sizeof (GdmXdmcpGreeterDisplayPrivate));
 
@@ -118,3 +121,15 @@
 
         return GDM_DISPLAY (object);
 }
+
+static gboolean
+gdm_xdmcp_greeter_display_finish (GdmDisplay *display)
+{
+        g_return_val_if_fail (GDM_IS_DISPLAY (display), FALSE);
+
+        GDM_DISPLAY_CLASS (gdm_xdmcp_greeter_display_parent_class)->finish (display);
+
+        gdm_display_unmanage(display);
+
+        return TRUE;
+}