Merge 123798 - Guard Prerenderer against inserting prerenders into detached documents.

Source/WebCore/loader/Prerenderer.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 54 matching lines @@
 
 Prerenderer::~Prerenderer()
 {
 }
 
 PassRefPtr<PrerenderHandle> Prerenderer::render(const KURL& url)
 {
     // Prerenders are unlike requests in most ways (for instance, they pass down fragments, and they don't return data),
     // but they do have referrers.
     const ReferrerPolicy referrerPolicy = document()->referrerPolicy();
+    
+    if (!document()->frame())
+        return 0;
+
     const String referrer = SecurityPolicy::generateReferrerHeader(referrerPolicy, url, document()->frame()->loader()->outgoingReferrer());
 
     RefPtr<PrerenderHandle> prerenderHandle = PrerenderHandle::create(url, referrer, referrerPolicy);
 
     client()->willAddPrerender(prerenderHandle.get());
     prerenderHandle->add();
 
     m_activeHandles.append(prerenderHandle);
     return prerenderHandle;
 }
@@ skipping 43 matching lines @@
 PrerendererClient* Prerenderer::client()
 {
     if (!m_client)
         m_client = PrerendererClient::from(document()->page());
     return m_client;
 }
 
 }
 
 #endif // ENABLE(LINK_PRERENDER)