[gdm] local-display-factory: call sync function after display finishes

[Ray Strode <halfline src gnome org>]

commit 7247ee14cf9db22e6e3608992e02dce16e6c1b59
Author: Ray Strode <rstrode redhat com>
Date:   Thu Sep 10 09:38:12 2015 -0400

    local-display-factory: call sync function after display finishes
    
    Right now if a local display finishes we create a new one of the
    same type to replace it.  But if a user display finishes we don't
    want to create a new user display, we want to create greeter
    display.  Furthermore if the user session is X11, we still want the
    login screen that comes up to be wayland by default.
    
    This commit changes the code to just call sync_seats after a display
    finishes, since sync_seats is where the logic for where the login
    screen display information is stored.
    
    sync_seats is idempotent anyway, and will only create displays for
    seats that need them, so it's safe to call it any time any local
    display finishes.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=749418

 daemon/gdm-local-display-factory.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)
---
diff --git a/daemon/gdm-local-display-factory.c b/daemon/gdm-local-display-factory.c
index 0898faa..676303c 100644
--- a/daemon/gdm-local-display-factory.c
+++ b/daemon/gdm-local-display-factory.c
@@ -80,6 +80,7 @@ static void     on_display_status_changed               (GdmDisplay
                                                          GParamSpec                  *arg1,
                                                          GdmLocalDisplayFactory      *factory);
 
+static gboolean gdm_local_display_factory_sync_seats    (GdmLocalDisplayFactory *factory);
 static gpointer local_display_factory_object = NULL;
 
 G_DEFINE_TYPE (GdmLocalDisplayFactory, gdm_local_display_factory, GDM_TYPE_DISPLAY_FACTORY)
@@ -285,12 +286,16 @@ on_display_status_changed (GdmDisplay             *display,
                 }
                 gdm_display_store_remove (store, display);
 
-                /* Create a new equivalent display if it was static */
+                /* if this is a local display, do a full resync.  Only
+                 * seats without displays will get created anyway.  This
+                 * ensures we get a new login screen when the user logs out,
+                 * if there isn't one.
+                 */
                 if (is_local) {
                         /* reset num failures */
                         factory->priv->num_failures = 0;
 
-                        create_display (factory, seat_id, session_type, is_initial);
+                        gdm_local_display_factory_sync_seats (factory);
                 }
                 break;
         case GDM_DISPLAY_FAILED: