GtkListBox: fix model binding refcount issue

As it is, GtkListBox model binding will work nicely as long as your
create_widget_func returns a floating reference on the newly-created
widget.

If you try to return a full reference (as any higher-level language
would do) then you will leak that reference.

Fix that up by converting any floating references into full references
and then unconditionally releasing the full reference after adding to
the box.

https://bugzilla.gnome.org/show_bug.cgi?id=746893

diff --git a/gtk/gtklistbox.c b/gtk/gtklistbox.c
index b270910a9a335304198e9197035d7dccf916bfaf..554cd42c98f2c0833c4f6405368fd9c04ffb5f77 100644 (file)
--- a/gtk/gtklistbox.c
+++ b/gtk/gtklistbox.c
@@ -3610,9 +3610,21 @@ gtk_list_box_bound_model_changed (GListModel *list,
 
       item = g_list_model_get_item (list, position + i);
       widget = priv->create_widget_func (item, priv->create_widget_func_data);
+
+      /* We allow the create_widget_func to either return a full
+       * reference or a floating reference.  If we got the floating
+       * reference, then turn it into a full reference now.  That means
+       * that gtk_list_box_insert() will take another full reference.
+       * Finally, we'll release this full reference below, leaving only
+       * the one held by the box.
+       */
+      if (g_object_is_floating (widget))
+        g_object_ref_sink (widget);
+
       gtk_widget_show_all (widget);
       gtk_list_box_insert (box, widget, position + i);
 
+      g_object_unref (widget);
       g_object_unref (item);
     }
 }