diff -r 000000000000 -r 6474c204b198 browser/components/customizableui/test/browser_941083_invalidate_wrapper_cache_createWidget.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/customizableui/test/browser_941083_invalidate_wrapper_cache_createWidget.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,31 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// See https://bugzilla.mozilla.org/show_bug.cgi?id=941083
+
+const kWidgetId = "test-invalidate-wrapper-cache";
+
+// Check createWidget invalidates the widget cache
+add_task(function() {
+  let groupWrapper = CustomizableUI.getWidget(kWidgetId);
+  ok(groupWrapper, "Should get group wrapper.");
+  let singleWrapper = groupWrapper.forWindow(window);
+  ok(singleWrapper, "Should get single wrapper.");
+
+  CustomizableUI.createWidget({id: kWidgetId, label: "Test invalidating widgets caching"});
+
+  let newGroupWrapper = CustomizableUI.getWidget(kWidgetId);
+  ok(newGroupWrapper, "Should get a group wrapper again.");
+  isnot(newGroupWrapper, groupWrapper, "Wrappers shouldn't be the same.");
+  isnot(newGroupWrapper.provider, groupWrapper.provider, "Wrapper providers shouldn't be the same.");
+
+  let newSingleWrapper = newGroupWrapper.forWindow(window);
+  isnot(newSingleWrapper, singleWrapper, "Single wrappers shouldn't be the same.");
+  isnot(newSingleWrapper.provider, singleWrapper.provider, "Single wrapper providers shouldn't be the same.");
+
+  CustomizableUI.destroyWidget(kWidgetId);
+  ok(!CustomizableUI.getWidget(kWidgetId), "Shouldn't get a wrapper after destroying the widget.");
+});