diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug599626.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug599626.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,70 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const TEST_URL = 'data:text/html,<script>window.onbeforeunload=' +
+                 'function(e){e.returnValue="?"}</script>';
+
+function test() {
+  waitForExplicitFinish();
+  showTabView(onTabViewShown);
+}
+
+function onTabViewShown() {
+  let contentWindow = TabView.getContentWindow();
+  let groupItemOne = contentWindow.GroupItems.getActiveGroupItem();
+  let groupItemTwo = createGroupItemWithTabs(window, 300, 300, 10, [TEST_URL]);
+
+  afterAllTabsLoaded(function () {
+    testStayOnPage(contentWindow, groupItemOne, groupItemTwo);
+  });
+}
+
+function testStayOnPage(contentWindow, groupItemOne, groupItemTwo) {
+  // We created a new tab group with a second tab above, so let's
+  // pick that second tab here and wait for its onbeforeunload dialog.
+  let browser = gBrowser.browsers[1];
+  waitForOnBeforeUnloadDialog(browser, function (btnLeave, btnStay) {
+    executeSoon(function () {
+      is(gBrowser.tabs.length, 2, 
+         "The total number of tab is 2 when staying on the page");
+      is(contentWindow.TabItems.getItems().length, 2, 
+         "The total number of tab items is 2 when staying on the page");
+
+      showTabView(function () {
+        // start the next test
+        testLeavePage(contentWindow, groupItemOne, groupItemTwo);
+      });
+    });
+
+    // stay on page
+    btnStay.click();
+  });
+
+  closeGroupItem(groupItemTwo);
+}
+
+function testLeavePage(contentWindow, groupItemOne, groupItemTwo) {
+  // The second tab hasn't been closed yet because we chose to stay. Wait
+  // for the onbeforeunload dialog again and leave the page this time.
+  let browser = gBrowser.browsers[1];
+  waitForOnBeforeUnloadDialog(browser, function (btnLeave, btnStay) {
+    // clean up and finish the test
+    groupItemTwo.addSubscriber("close", function onClose() {
+      groupItemTwo.removeSubscriber("close", onClose);
+
+      is(gBrowser.tabs.length, 1,
+         "The total number of tab is 1 after leaving the page");
+      is(contentWindow.TabItems.getItems().length, 1, 
+         "The total number of tab items is 1 after leaving the page");
+
+      hideTabView(finish);
+    });
+
+    // Leave page
+    btnLeave.click();
+  });
+
+  closeGroupItem(groupItemTwo);
+}