[gnome-panel] status-notifier: don't crash if layout has incorrect type

[Alberts Muktupāvels <muktupavels src gnome org>]

commit a08f238147660b3d70e5eebd8d24707711424719
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Fri Dec 29 00:42:05 2017 +0200

    status-notifier: don't crash if layout has incorrect type
    
    It should be '(ia{sv}av)'...

 modules/status-notifier/sn-dbus-menu.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/modules/status-notifier/sn-dbus-menu.c b/modules/status-notifier/sn-dbus-menu.c
index 9cbab34..4f28f49 100644
--- a/modules/status-notifier/sn-dbus-menu.c
+++ b/modules/status-notifier/sn-dbus-menu.c
@@ -127,6 +127,15 @@ layout_parse (SnDBusMenu *menu,
   GVariantIter iter;
   GVariant *child;
 
+  if (!g_variant_is_of_type (layout, G_VARIANT_TYPE ("(ia{sv}av)")))
+    {
+      g_warning ("Type of return value for 'layout' property in "
+                 "'GetLayout' call should be '(ia{sv}av)' but got '%s'",
+                 g_variant_get_type_string (layout));
+
+      return;
+    }
+
   g_variant_get (layout, "(i@a{sv}@av)", &id, &props, &items);
 
   submenu = layout_update_item (menu, gtk_menu, id, props);