[gdm/gnome-3-16] manager: fix display leak

[Federico Mena Quintero <federico src gnome org>]

commit 575ed30021b50599582e699a0b00c5b718962a86
Author: Ray Strode <rstrode redhat com>
Date:   Thu Sep 10 09:35:52 2015 -0400

    manager: fix display leak
    
    If we're doing autologin then we prepare a stub greeter display that
    we don't actually end up using.  This commit makes sure the greeter
    display gets cleaned up so it doesn't stick around in the display
    store forever.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=749418

 daemon/gdm-manager.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/daemon/gdm-manager.c b/daemon/gdm-manager.c
index bfd5588..ee907c5 100644
--- a/daemon/gdm-manager.c
+++ b/daemon/gdm-manager.c
@@ -2007,6 +2007,10 @@ on_start_user_session (StartUserSessionOperation *operation)
                 g_object_set_data (G_OBJECT (display), "gdm-embryonic-user-session", NULL);
                 g_object_set_data (G_OBJECT (operation->session), "gdm-display", NULL);
                 create_embryonic_user_session_for_display (operation->manager, display, allowed_uid);
+
+                /* remove the unused prepared greeter display since we're not going
+                 * to have a greeter */
+                gdm_display_store_remove (self->priv->display_store, display);
                 g_object_unref (display);
 
                 /* Give the user session a new display object for bookkeeping purposes */