[gnome-games] ui: Check for null in SidebarView.model setter

[Adrien Plazas <aplazas src gnome org>]

commit ab5bb2e33c8df13a385e64ae3e67c29b74ac684e
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Wed Aug 15 01:17:52 2018 +0500

    ui: Check for null in SidebarView.model setter
    
    Prevents runtime warnings on connecting handlers to a null object.

 src/ui/sidebar-view.vala | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/src/ui/sidebar-view.vala b/src/ui/sidebar-view.vala
index 5420546b..16bd21ff 100644
--- a/src/ui/sidebar-view.vala
+++ b/src/ui/sidebar-view.vala
@@ -13,7 +13,9 @@ private abstract class Games.SidebarView : Gtk.Box {
                set {
                        _model = value;
                        collection_view.model = _model;
-                       model.items_changed.connect (on_model_changed);
+
+                       if (model != null)
+                               model.items_changed.connect (on_model_changed);
                }
                get { return _model; }
        }