adaptor: Fix missing events at startup

We need to register the application before anything else happens,
otherwise we might miss some events sent before registration.

As we want to register only from the main loop to avoid registering
an application that won't respond to calls [1], we used an idle
callback; but it doesn't run early enough in all cases, e.g. in
Firefox.  So, switch to a high-priority 0-timeout so that it should be
dispatched among the first ones in the next main loop iteration, then
being run before other callbacks that might generate events.

Fixes https://gitlab.gnome.org/GNOME/gtk/issues/2186

[1] https://gitlab.gnome.org/GNOME/at-spi2-core/issues/16

1 files changed, 31 insertions, 11 deletions

diff --git a/atk-adaptor/bridge.c b/atk-adaptor/bridge.c
index 06407f4..8579185 100644
--- a/atk-adaptor/bridge.c
+++ b/atk-adaptor/bridge.c
@@ -403,8 +403,8 @@ register_reply (DBusPendingCall *pending, void *user_data)
     get_registered_event_listeners (spi_global_app_data);
 }
 
-gboolean
-_atk_bridge_register_application (gpointer data)
+static gboolean
+register_application (gpointer data)
 {
   SpiBridge * app = data;
   DBusMessage *message;
@@ -439,6 +439,31 @@ _atk_bridge_register_application (gpointer data)
   return FALSE;
 }
 
+void
+_atk_bridge_schedule_application_registration (SpiBridge *app)
+{
+  /* We need the callback to be called first thing, before any other of ours
+   * (and possibly of client apps), so use a high priority and a short timeout
+   * to try and be called first by the main loop. */
+  if (!app->registration_pending)
+    app->registration_pending = spi_timeout_add_full (G_PRIORITY_HIGH, 0,
+                                                      register_application,
+                                                      app, NULL);
+}
+
+gboolean
+_atk_bridge_remove_pending_application_registration (SpiBridge *app)
+{
+  if (app->registration_pending)
+  {
+    g_source_remove (app->registration_pending);
+    app->registration_pending = 0;
+    return TRUE;
+  }
+
+  return FALSE;
+}
+
 /*---------------------------------------------------------------------------*/
 
 static void
@@ -470,12 +495,8 @@ deregister_application (SpiBridge * app)
   DBusMessageIter iter;
   const char *uname;
 
-  if (spi_global_app_data->registration_pending)
-  {
-    g_source_remove (spi_global_app_data->registration_pending);
-    spi_global_app_data->registration_pending = 0;
+  if (_atk_bridge_remove_pending_application_registration (spi_global_app_data))
     return;
-  }
 
   message = dbus_message_new_method_call (SPI_DBUS_NAME_REGISTRY,
                                           ATSPI_DBUS_PATH_REGISTRY,
@@ -850,7 +871,7 @@ signal_filter (DBusConnection *bus, DBusMessage *message, void *user_data)
             {
               if (registry_lost && !old[0])
                 {
-                  _atk_bridge_register_application (spi_global_app_data);
+                  register_application (spi_global_app_data);
                   registry_lost = FALSE;
                 }
               else if (!new[0])
@@ -1105,9 +1126,8 @@ atk_bridge_adaptor_init (gint * argc, gchar ** argv[])
                               NULL);
 
   /* Register this app by sending a signal out to AT-SPI registry daemon */
-  if (!atspi_no_register && (!root || !ATK_IS_PLUG (root)) &&
-      !spi_global_app_data->registration_pending)
-    spi_global_app_data->registration_pending = spi_idle_add (_atk_bridge_register_application, spi_global_app_data);
+  if (!atspi_no_register && (!root || !ATK_IS_PLUG (root)))
+    _atk_bridge_schedule_application_registration (spi_global_app_data);
   else
     get_registered_event_listeners (spi_global_app_data);