[gdm/gnome-2-30] Only set username if possible.

[Brian Cameron <bcameron src gnome org>]

commit 29ac5a6ca91f5dce4f312eb1539d0e8912c80d2e
Author: Brian Cameron <brian cameron oracle com>
Date:   Thu Jun 2 09:51:39 2011 -0500

    Only set username if possible.

 daemon/gdm-simple-slave.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/daemon/gdm-simple-slave.c b/daemon/gdm-simple-slave.c
index fa8d4b6..0b96abb 100644
--- a/daemon/gdm-simple-slave.c
+++ b/daemon/gdm-simple-slave.c
@@ -345,7 +345,10 @@ stop_greeter (GdmSimpleSlave *slave)
         }
 
         /* Run the PostLogin script. gdmslave suspends until script has terminated */
-        username = gdm_session_direct_get_username (slave->priv->session);
+        username = NULL;
+        if (slave->priv->session != NULL) {
+                username = gdm_session_direct_get_username (slave->priv->session);
+        }
 
         if (username != NULL) {
                 gdm_slave_run_script (GDM_SLAVE (slave), GDMCONFDIR "/PostLogin", username);