shell/tray-manager: Delay managing screen if necessary

Now that Xwayland startup is asynchronous, the function may be called
before X11 is available, resulting in a crash.

Fix this by only managing the tray immediately if we already have an
X11 display, and wait for it to be set up otherwise.

Likewise, unmanage the screen when X11 becomes unavailable.

https://gitlab.gnome.org/GNOME/gnome-shell/issues/2308

diff --git a/src/shell-tray-manager.c b/src/shell-tray-manager.c
index ea7066be67be8993feea21ae79473bc53e262234..e23179f4ed7fa60ce9a3d24f4f187edb798b170c 100644 (file)
--- a/src/shell-tray-manager.c
+++ b/src/shell-tray-manager.c
@@ -218,6 +218,9 @@ shell_tray_manager_style_changed (StWidget *theme_widget,
   StThemeNode *theme_node;
   StIconColors *icon_colors;
 
+  if (manager->priv->na_manager == NULL)
+    return;
+
   theme_node = st_widget_get_theme_node (theme_widget);
   icon_colors = st_theme_node_get_icon_colors (theme_node);
   na_tray_manager_set_colors (manager->priv->na_manager,
@@ -225,15 +228,30 @@ shell_tray_manager_style_changed (StWidget *theme_widget,
                               &icon_colors->error, &icon_colors->success);
 }
 
+static void
+shell_tray_manager_manage_screen_internal (ShellTrayManager *manager)
+{
+  shell_tray_manager_ensure_resources (manager);
+  na_tray_manager_manage_screen (manager->priv->na_manager);
+}
+
 void
 shell_tray_manager_manage_screen (ShellTrayManager *manager,
                                   StWidget         *theme_widget)
 {
+  MetaDisplay *display = shell_global_get_display (shell_global_get ());
+
   g_set_weak_pointer (&manager->priv->theme_widget, theme_widget);
 
-  shell_tray_manager_ensure_resources (manager);
+  if (meta_display_get_x11_display (display) != NULL)
+    shell_tray_manager_manage_screen_internal (manager);
 
-  na_tray_manager_manage_screen (manager->priv->na_manager);
+  g_signal_connect_object (display, "x11-display-setup",
+                           G_CALLBACK (shell_tray_manager_manage_screen_internal),
+                           manager, G_CONNECT_SWAPPED);
+  g_signal_connect_object (display, "x11-display-closing",
+                           G_CALLBACK (shell_tray_manager_release_resources),
+                           manager, G_CONNECT_SWAPPED);
 
   g_signal_connect_object (theme_widget, "style-changed",
                            G_CALLBACK (shell_tray_manager_style_changed),
@@ -244,6 +262,10 @@ shell_tray_manager_manage_screen (ShellTrayManager *manager,
 void
 shell_tray_manager_unmanage_screen (ShellTrayManager *manager)
 {
+  MetaDisplay *display = shell_global_get_display (shell_global_get ());
+
+  g_signal_handlers_disconnect_by_data (display, manager);
+
   if (manager->priv->theme_widget != NULL)
     {
       g_signal_handlers_disconnect_by_func (manager->priv->theme_widget,