diff -r 000000000000 -r 6474c204b198 browser/base/content/test/general/browser_bug647886.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/base/content/test/general/browser_bug647886.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,36 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  waitForExplicitFinish();
+
+  gBrowser.selectedTab = gBrowser.addTab();
+  gBrowser.selectedBrowser.addEventListener("load", function () {
+    gBrowser.selectedBrowser.removeEventListener("load", arguments.callee, true);
+
+    content.history.pushState({}, "2", "2.html");
+
+    testBackButton();
+  }, true);
+
+  loadURI("http://example.com");
+}
+
+function testBackButton() {
+  var backButton = document.getElementById("back-button");
+  var rect = backButton.getBoundingClientRect();
+
+  info("waiting for the history menu to open");
+
+  backButton.addEventListener("popupshown", function (event) {
+    backButton.removeEventListener("popupshown", arguments.callee, false);
+
+    ok(true, "history menu opened");
+    event.target.hidePopup();
+    gBrowser.removeTab(gBrowser.selectedTab);
+    finish();
+  }, false);
+
+  EventUtils.synthesizeMouseAtCenter(backButton, {type: "mousedown"});
+  EventUtils.synthesizeMouse(backButton, rect.width / 2, rect.height, {type: "mouseup"});
+}