[mutter] backends/native: Only emit layout group changed event when changed

[Jonas Ådahl <jadahl src gnome org>]

commit 517488ef670622fd5c3bffca2af96beae08d8a08
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Aug 21 14:37:52 2017 +0800

    backends/native: Only emit layout group changed event when changed
    
    Check that the layout group changed before emitting a changed event.

 src/backends/native/meta-backend-native.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index 5ebe791..7a5c2b6 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/src/backends/native/meta-backend-native.c
@@ -520,6 +520,11 @@ meta_backend_native_lock_layout_group (MetaBackend *backend,
                                        guint        idx)
 {
   ClutterDeviceManager *manager = clutter_device_manager_get_default ();
+  xkb_layout_index_t old_idx;
+
+  old_idx = meta_backend_native_get_keymap_layout_group (backend);
+  if (old_idx == idx)
+    return;
 
   clutter_evdev_set_keyboard_layout_index (manager, idx);
   meta_backend_notify_keymap_layout_group_changed (backend, idx);