diff -r 000000000000 -r 6474c204b198 browser/components/customizableui/test/browser_927717_customize_drag_empty_toolbar.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/customizableui/test/browser_927717_customize_drag_empty_toolbar.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,26 @@
+/* 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";
+
+const kTestToolbarId = "test-empty-drag";
+
+// Attempting to drag an item to an empty container should work.
+add_task(function() {
+  yield createToolbarWithPlacements(kTestToolbarId, []);
+  yield startCustomizing();
+  let downloadButton = document.getElementById("downloads-button");
+  let customToolbar = document.getElementById(kTestToolbarId);
+  simulateItemDrag(downloadButton, customToolbar);
+  assertAreaPlacements(kTestToolbarId, ["downloads-button"]);
+  ok(downloadButton.parentNode && downloadButton.parentNode.parentNode == customToolbar,
+     "Button should really be in toolbar");
+  yield endCustomizing();
+  removeCustomToolbars();
+});
+
+add_task(function asyncCleanup() {
+  yield endCustomizing();
+  yield resetCustomization();
+});