diff -r 000000000000 -r 6474c204b198 browser/components/customizableui/test/browser_973932_addonbar_currentset.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/customizableui/test/browser_973932_addonbar_currentset.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+/* 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";
+
+let addonbarID = CustomizableUI.AREA_ADDONBAR;
+let addonbar = document.getElementById(addonbarID);
+
+// Check that currentset is correctly updated after a reset:
+add_task(function() {
+  let placements = CustomizableUI.getWidgetIdsInArea(addonbarID);
+  is(placements.join(','), addonbar.getAttribute("currentset"), "Addon-bar currentset should match default placements");
+  ok(CustomizableUI.inDefaultState, "Should be in default state");
+  info("Adding a spring to add-on bar shim");
+  CustomizableUI.addWidgetToArea("spring", addonbarID, 1);
+  ok(addonbar.getElementsByTagName("toolbarspring").length, "There should be a spring in the toolbar");
+  ok(!CustomizableUI.inDefaultState, "Should no longer be in default state");
+  placements = CustomizableUI.getWidgetIdsInArea(addonbarID);
+  is(placements.join(','), addonbar.getAttribute("currentset"), "Addon-bar currentset should match placements after spring addition");
+
+  yield startCustomizing();
+  yield gCustomizeMode.reset();
+  ok(CustomizableUI.inDefaultState, "Should be in default state after reset");
+  placements = CustomizableUI.getWidgetIdsInArea(addonbarID);
+  is(placements.join(','), addonbar.getAttribute("currentset"), "Addon-bar currentset should match default placements after reset");
+  ok(!addonbar.getElementsByTagName("toolbarspring").length, "There should be no spring in the toolbar");
+  yield endCustomizing();
+});
+