Bug 616919 - Make "History > Home" work on Mac if no browser windows are open. r=mano a=blocker

browser/base/content/browser.js

@@ -1984,6 +1984,7 @@ function BrowserGoHome(aEvent) {
 
   // Home page should open in a new tab when current tab is an app tab
   if (where == "current" &&
+      gBrowser &&
       gBrowser.selectedTab.pinned)
     where = "tab";