The Tor Browser / file revision

 function test() {

   waitForExplicitFinish();

   var tab1 = gBrowser.addTab("data:text/plain;charset=utf-8,foo");

   gBrowser.pinTab(tab1);

   whenBrowserLoaded(tab1.linkedBrowser, function() {

     var tab2 = gBrowser.addTab();

     gBrowser.pinTab(tab2);

     is(Array.indexOf(gBrowser.tabs, tab1), 0, "pinned tab 1 is at the first position");

     gBrowser.removeTab(tab1);

     tab1 = undoCloseTab();

     ok(tab1.pinned, "pinned tab 1 has been restored as a pinned tab");

     is(Array.indexOf(gBrowser.tabs, tab1), 0, "pinned tab 1 has been restored to the first position");

     gBrowser.removeTab(tab1);

     gBrowser.removeTab(tab2);

     finish();

   });

 }