[gdm] worker: ignore '' username

[Ray Strode <halfline src gnome org>]

commit 29def8761bbac04cf84c7f83722bed447d5d03c6
Author: Ray Strode <rstrode redhat com>
Date:   Wed Jan 8 11:46:24 2014 -0500

    worker: ignore '' username
    
    Some PAM modules set a "" username to mean "user not set yet",
    apparently, instead of NULL.
    
    This commit guards against that to prevent a crash.
    
    Red-Hat-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=965370
    
    https://bugzilla.gnome.org/show_bug.cgi?id=721803

 daemon/gdm-session-worker.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/daemon/gdm-session-worker.c b/daemon/gdm-session-worker.c
index 8c4dc3a..f285013 100644
--- a/daemon/gdm-session-worker.c
+++ b/daemon/gdm-session-worker.c
@@ -655,6 +655,7 @@ gdm_session_worker_update_username (GdmSessionWorker *worker)
                  * to keep trying to read settings)
                  */
                 if (worker->priv->username != NULL &&
+                    worker->priv->username[0] != '\0' &&
                     !gdm_session_settings_is_loaded (worker->priv->user_settings)) {
                         attempt_to_load_user_settings (worker, worker->priv->username);
                 }