[gnome-terminal/gnome-3-4] Make eggsmclient work on non-X backends

[Alexander Larsson <alexl src gnome org>]

commit 32b87be1e1d1fea0b872cc0c916dade6dff6c712
Author: Alexander Larsson <alexl redhat com>
Date:   Wed Jan 25 14:08:58 2012 +0100

    Make eggsmclient work on non-X backends
    
    This cherry picks commit 7ceb9c1fb72f21f8887d25bbba1360b8ed56a0a7 from
    libegg.

 src/eggsmclient-xsmp.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/src/eggsmclient-xsmp.c b/src/eggsmclient-xsmp.c
index c410332..6ef632c 100644
--- a/src/eggsmclient-xsmp.c
+++ b/src/eggsmclient-xsmp.c
@@ -200,6 +200,11 @@ egg_sm_client_xsmp_class_init (EggSMClientXSMPClass *klass)
 EggSMClient *
 egg_sm_client_xsmp_new (void)
 {
+#if GTK_CHECK_VERSION(3,0,0)
+  if (!GDK_IS_X11_DISPLAY_MANAGER (gdk_display_manager_get ()))
+    return NULL;
+#endif
+
   if (!g_getenv ("SESSION_MANAGER"))
     return NULL;