function numClosedTabs() Cc["@mozilla.org/browser/sessionstore;1"]. getService(Ci.nsISessionStore). getClosedTabCount(window); function isUndoCloseEnabled() { document.popupNode = gBrowser.tabs[0]; TabContextMenu.updateContextMenu(document.getElementById("tabContextMenu")); return !document.getElementById("context_undoCloseTab").disabled; } function test() { waitForExplicitFinish(); gPrefService.setIntPref("browser.sessionstore.max_tabs_undo", 0); gPrefService.clearUserPref("browser.sessionstore.max_tabs_undo"); is(numClosedTabs(), 0, "There should be 0 closed tabs."); ok(!isUndoCloseEnabled(), "Undo Close Tab should be disabled."); var tab = gBrowser.addTab("http://mochi.test:8888/"); var browser = gBrowser.getBrowserForTab(tab); browser.addEventListener("load", function() { browser.removeEventListener("load", arguments.callee, true); gBrowser.removeTab(tab); ok(isUndoCloseEnabled(), "Undo Close Tab should be enabled."); finish(); }, true); }