Add missing null handle check to document wrapper caching code....

webkit/port/bindings/v8/v8_proxy.cpp

 // Copyright (c) 2008, 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 1824 matching lines @@
     // might get deleted and the global handle for the document
     // wrapper cleared. Using the cleared global handle will lead to
     // crashes.  In this case we clear the cache and let the DOMWindow
     // accessor handle access to the document.
     if (!m_frame->document()->frame()) {
         ClearDocumentWrapperCache();
         return;
     }
 
     v8::Handle<v8::Value> document_wrapper = NodeToV8Object(m_frame->document());
+
+    // If instantiation of the document wrapper fails, clear the cache
+    // and let the DOMWindow accessor handle access to the document.
+    if (document_wrapper.IsEmpty()) {
+        ClearDocumentWrapperCache();
+        return;
+    }
+
     m_context->Global()->ForceSet(v8::String::New("document"),
                                   document_wrapper,
                                   static_cast<v8::PropertyAttribute>(v8::ReadOnly | v8::DontDelete));
 }
 
 
 void V8Proxy::ClearDocumentWrapperCache()
 {
     ASSERT(!m_context.IsEmpty());
     m_context->Global()->ForceDelete(v8::String::New("document"));
@@ skipping 1612 matching lines @@
   v8::HandleScope scope;
   if (!context->GetData()->IsObject()) {
     return -1;
   }
   v8::Handle<v8::Value> data = context->GetData()->ToObject()->Get(
       v8::String::New(kContextDebugDataValue));
   return data->IsInt32() ? data->Int32Value() : -1;
 }
 
 }  // namespace WebCore