From abd8e1ef71d093a3ab5c110aea5fa2012d59d5e2 Mon Sep 17 00:00:00 2001

From: Ray Strode <rstrode@redhat.com>

Date: Tue, 14 Aug 2018 10:21:17 -0400

Subject: [PATCH 21/51] local-display-factory: ignore spurios SeatNew signal at

 start up

Sometimes during startup, logind will send a `SeatNew` signal for

seat0 after GDM has already called `ListSeats` and processed `seat0`.

That `SeatNew` signal leads to GDM calling `create_display` twice in

quick succession.

This commit changes GDM to avoid such double processing, by ignoring

the `create_display` requests for seats that already have a prepared

display ("prepared" means "starting up").

Closes: https://gitlab.gnome.org/GNOME/gdm/issues/410

---

 daemon/gdm-local-display-factory.c | 33 +++++++++++++++++++++++-------

 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/daemon/gdm-local-display-factory.c b/daemon/gdm-local-display-factory.c

index 6f3a4c391..127127005 100644

--- a/daemon/gdm-local-display-factory.c

+++ b/daemon/gdm-local-display-factory.c

@@ -353,107 +353,126 @@ on_display_status_changed (GdmDisplay             *display,

         case GDM_DISPLAY_MANAGED:

                 break;

         default:

                 g_assert_not_reached ();

                 break;

         }

         g_free (seat_id);

         g_free (session_type);

         g_free (session_class);

 }

 static gboolean

 lookup_by_seat_id (const char *id,

                    GdmDisplay *display,

                    gpointer    user_data)

 {

         const char *looking_for = user_data;

         char *current;

         gboolean res;

         g_object_get (G_OBJECT (display), "seat-id", &current, NULL);

         res = g_strcmp0 (current, looking_for) == 0;

         g_free(current);

         return res;

 }

+static gboolean

+lookup_prepared_display_by_seat_id (const char *id,

+                                    GdmDisplay *display,

+                                    gpointer    user_data)

+{

+        int status;

+

+        status = gdm_display_get_status (display);

+

+        if (status != GDM_DISPLAY_PREPARED)

+                return FALSE;

+

+        return lookup_by_seat_id (id, display, user_data);

+}

+

 static GdmDisplay *

 create_display (GdmLocalDisplayFactory *factory,

                 const char             *seat_id,

                 const char             *session_type,

                 gboolean                initial)

 {

         GdmDisplayStore *store;

         GdmDisplay      *display = NULL;

         char            *active_session_id = NULL;

         int              ret;

         g_debug ("GdmLocalDisplayFactory: %s login display for seat %s requested",

                  session_type? : "X11", seat_id);

         store = gdm_display_factory_get_display_store (GDM_DISPLAY_FACTORY (factory));

+        if (sd_seat_can_multi_session (seat_id))

+                display = gdm_display_store_find (store, lookup_prepared_display_by_seat_id, (gpointer) seat_id);

+        else

+                display = gdm_display_store_find (store, lookup_by_seat_id, (gpointer) seat_id);

+

+        /* Ensure we don't create the same display more than once */

+        if (display != NULL) {

+                g_debug ("GdmLocalDisplayFactory: display already created");

+                return NULL;

+        }

+

         ret = sd_seat_get_active (seat_id, &active_session_id, NULL);

         if (ret == 0) {

                 char *login_session_id = NULL;

                 /* If we already have a login window, switch to it */

                 if (gdm_get_login_window_session_id (seat_id, &login_session_id)) {

                         GdmDisplay *display;

                         display = gdm_display_store_find (store,

                                                           lookup_by_session_id,

                                                           (gpointer) login_session_id);

                         if (display != NULL && gdm_display_get_status (display) == GDM_DISPLAY_MANAGED) {

                                 if (g_strcmp0 (active_session_id, login_session_id) != 0) {

                                         g_debug ("GdmLocalDisplayFactory: session %s found, activating.",

                                                  login_session_id);

                                         gdm_activate_session_by_id (factory->priv->connection, seat_id, login_session_id);

                                 }

                                 g_clear_pointer (&login_session_id, g_free);

                                 g_clear_pointer (&active_session_id, g_free);

                                 return NULL;

                         }

                         g_clear_pointer (&login_session_id, g_free);

                 }

                 g_clear_pointer (&active_session_id, g_free);

-        } else if (!sd_seat_can_multi_session (seat_id)) {

-                /* Ensure we don't create the same display more than once */

-                display = gdm_display_store_find (store, lookup_by_seat_id, (gpointer) seat_id);

-

-                if (display != NULL) {

-                        return NULL;

-                }

         }

         g_debug ("GdmLocalDisplayFactory: Adding display on seat %s", seat_id);

 #ifdef ENABLE_USER_DISPLAY_SERVER

         if (g_strcmp0 (seat_id, "seat0") == 0) {

                 display = gdm_local_display_new ();

                 if (session_type != NULL) {

                         g_object_set (G_OBJECT (display), "session-type", session_type, NULL);

                 }

         }

 #endif

         if (display == NULL) {

                 guint32 num;

                 num = take_next_display_number (factory);

                 display = gdm_legacy_display_new (num);

         }

         g_object_set (display, "seat-id", seat_id, NULL);

         g_object_set (display, "is-initial", initial, NULL);

         store_display (factory, display);

         /* let store own the ref */

         g_object_unref (display);

         if (! gdm_display_manage (display)) {

-- 

2.27.0