Fix for #1176

platform/firefox/vapi-background.js

@@ -1326,7 +1326,9 @@ vAPI.net.registerListeners = function() {
         var details = e.data;
         var browser = e.target;
         var tabId = vAPI.tabs.getTabId(browser);
-
+        if (tabId === vAPI.noTabId) {
+            return; // Do not navigate for behind the scenes
+        }
         //console.debug("nsIWebProgressListener: onLocationChange: " + details.url + " (" + details.flags + ")");        
 
         // LOCATION_CHANGE_SAME_DOCUMENT = "did not load a new document"

src/js/popup.js

@@ -743,7 +743,7 @@ uDom.onLoad(function () {
     var tabId = null; //If there's no tab ID specified in the query string, it will default to current tab.
 
     // Extract the tab id of the page this popup is for
-    var matches = window.location.search.match(/[\?&]tabId=([^&]+)/);
+    var matches = window.location && window.location.search.match(/[\?&]tabId=([^&]+)/);
     if (matches && matches.length === 2) {
         tabId = matches[1];
     }