[gtk+] gtkapplication: _get_app_menu can return NULL

[Timm Bäder <baedert src gnome org>]

commit aeed695e26619c009f72cb72fcae8bcd50713da6
Author: Timm Bäder <mail baedert org>
Date:   Mon Mar 28 18:18:20 2016 +0200

    gtkapplication: _get_app_menu can return NULL

 gtk/gtkapplication.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkapplication.c b/gtk/gtkapplication.c
index a595e85..ace8b15 100644
--- a/gtk/gtkapplication.c
+++ b/gtk/gtkapplication.c
@@ -1402,7 +1402,8 @@ gtk_application_set_app_menu (GtkApplication *application,
  * Returns the menu model that has been set with
  * gtk_application_set_app_menu().
  *
- * Returns: (transfer none): the application menu of @application
+ * Returns: (transfer none) (nullable): the application menu of @application
+ *   or %NULL if no application menu has been set.
  *
  * Since: 3.4
  */