Issue 3458 - When blocking pop-ups, consider the case where window.opener becomes null due to redir…

lib/child/contentPolicy.js

Index: lib/child/contentPolicy.js
===================================================================
--- a/lib/child/contentPolicy.js
+++ b/lib/child/contentPolicy.js
@@ -306,43 +306,46 @@ var PolicyImplementation =
   shouldProcess: function(contentType, contentLocation, requestOrigin, insecNode, mimeType, extra)
   {
     return Ci.nsIContentPolicy.ACCEPT;
   },
 
   //
   // nsIObserver interface implementation
   //
-  observe: function(subject, topic, data, additional)
+  observe: function(subject, topic, data, uri, opener)
   {
     switch (topic)
     {
       case "content-document-global-created":
       {
-        if (!(subject instanceof Ci.nsIDOMWindow) || !subject.opener)
+        if (!opener && subject instanceof Ci.nsIDOMWindow)
+          opener = subject.opener;
+        if (!opener)
           return;
 
-        let uri = additional || subject.location.href;
-        if (!shouldAllow(subject.opener, subject.opener.document, "POPUP", uri))
+        if (!uri && subject instanceof Ci.nsIDOMWindow)
+          uri = subject.location.href;
+        if (!shouldAllow(opener, opener.document, "POPUP", uri))
         {
           subject.stop();
           Utils.runAsync(() => subject.close());
         }
         else if (uri == "about:blank")
         {
           // An about:blank pop-up most likely means that a load will be
           // initiated asynchronously. Wait for that.
           Utils.runAsync(() =>
           {
             let channel = subject.QueryInterface(Ci.nsIInterfaceRequestor)
                                  .getInterface(Ci.nsIDocShell)
                                  .QueryInterface(Ci.nsIDocumentLoader)
                                  .documentChannel;
             if (channel)
-              this.observe(subject, topic, data, channel.URI.spec);
+              this.observe(subject, topic, data, channel.URI.spec, opener);
           });
         }
         break;
       }
     }
   },
 
   //