The Tor Browser / file revision

 /* 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/. */

 function test() {

   let tab1 = gBrowser.selectedTab;

   let tab2 = gBrowser.addTab("about:blank", {skipAnimation: true});

   let tab3 = gBrowser.addTab();

   gBrowser.selectedTab = tab2;

   gBrowser.removeCurrentTab({animate: true});

   gBrowser.tabContainer.advanceSelectedTab(-1, true);

   is(gBrowser.selectedTab, tab1, "First tab should be selected");

   gBrowser.removeTab(tab2);

   // test for "null has no properties" fix. See Bug 585830 Comment 13

   gBrowser.removeCurrentTab({animate: true});

   try {

     gBrowser.tabContainer.advanceSelectedTab(-1, false);

   } catch(err) {

     ok(false, "Shouldn't throw");

   }

   gBrowser.removeTab(tab1);

 }