[gnome-photos] selection-controller: Stop redundant emissions of selection-changed

[Debarshi Ray <debarshir src gnome org>]

commit b7e1880acdcdc642e5f542b9d93471ca8ae68c70
Author: Debarshi Ray <debarshir gnome org>
Date:   Mon Oct 26 12:59:57 2015 +0100

    selection-controller: Stop redundant emissions of selection-changed

 src/photos-selection-controller.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/photos-selection-controller.c b/src/photos-selection-controller.c
index 18363b7..b7b19c5 100644
--- a/src/photos-selection-controller.c
+++ b/src/photos-selection-controller.c
@@ -215,6 +215,9 @@ photos_selection_controller_set_selection (PhotosSelectionController *self, GLis
   if (priv->is_frozen)
     return;
 
+  if (priv->selection == NULL && selection == NULL)
+    return;
+
   g_list_free_full (priv->selection, g_free);
   priv->selection = NULL;