[gdm] session: fix session type selection if not explicitly chosen

[Ray Strode <halfline src gnome org>]

commit 4bb106f28551ccb9eaaa74137e52b5ef72f7d173
Author: Ray Strode <rstrode redhat com>
Date:   Tue Mar 17 10:05:10 2015 -0400

    session: fix session type selection if not explicitly chosen
    
    If we read the saved selection from user data, we don't select
    the right session type.
    
    This commit makes sure any time the selection is changed, we check
    if the session is wayland or X11.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=746348

 daemon/gdm-session.c |   36 ++++++++++++++++++++++++------------
 1 files changed, 24 insertions(+), 12 deletions(-)
---
diff --git a/daemon/gdm-session.c b/daemon/gdm-session.c
index 51bd5c4..f8522eb 100644
--- a/daemon/gdm-session.c
+++ b/daemon/gdm-session.c
@@ -174,6 +174,7 @@ enum {
 #ifdef ENABLE_WAYLAND_SUPPORT
 static gboolean gdm_session_is_wayland_session (GdmSession *self);
 #endif
+static void update_session_type (GdmSession *self);
 static void set_session_type (GdmSession *self,
                               const char *session_type);
 static guint signals [LAST_SIGNAL] = { 0, };
@@ -905,6 +906,8 @@ worker_on_saved_session_name_read (GdmDBusWorker          *worker,
                 g_free (self->priv->saved_session);
                 self->priv->saved_session = g_strdup (session_name);
 
+                update_session_type (self);
+
                 if (self->priv->greeter_interface != NULL) {
                         gdm_dbus_greeter_emit_default_session_name_changed (self->priv->greeter_interface,
                                                                             session_name);
@@ -2875,6 +2878,21 @@ out:
 }
 #endif
 
+static void
+update_session_type (GdmSession *self)
+{
+#ifdef ENABLE_WAYLAND_SUPPORT
+        gboolean is_wayland_session;
+
+        is_wayland_session = gdm_session_is_wayland_session (self);
+        if (is_wayland_session) {
+                set_session_type (self, "wayland");
+        } else {
+                set_session_type (self, NULL);
+        }
+#endif
+}
+
 gboolean
 gdm_session_bypasses_xsession (GdmSession *self)
 {
@@ -2994,21 +3012,13 @@ gdm_session_select_session (GdmSession *self,
 {
         GHashTableIter iter;
         gpointer key, value;
-        gboolean is_wayland_session = FALSE;
 
         g_debug ("GdmSession: selecting session '%s'", text);
 
         g_free (self->priv->selected_session);
         self->priv->selected_session = g_strdup (text);
 
-#ifdef ENABLE_WAYLAND_SUPPORT
-        is_wayland_session = gdm_session_is_wayland_session (self);
-        if (is_wayland_session) {
-                set_session_type (self, "wayland");
-        } else {
-                set_session_type (self, NULL);
-        }
-#endif
+        update_session_type (self);
 
         g_hash_table_iter_init (&iter, self->priv->conversations);
         while (g_hash_table_iter_next (&iter, &key, &value)) {
@@ -3114,9 +3124,11 @@ set_session_type (GdmSession *self,
                   const char *session_type)
 {
 
-        g_debug ("GdmSession: setting session to type '%s'", session_type? session_type : "");
-        g_free (self->priv->session_type);
-        self->priv->session_type = g_strdup (session_type);
+        if (g_strcmp0 (session_type, session_type) != 0) {
+                g_debug ("GdmSession: setting session to type '%s'", session_type? session_type : "");
+                g_free (self->priv->session_type);
+                self->priv->session_type = g_strdup (session_type);
+        }
 }
 
 static void