document.open(): gracefully handle exception thrown on window.open access.

Source/bindings/v8/custom/V8HTMLDocumentCustom.cpp

 /*
  * Copyright (C) 2007, 2008, 2009 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 47 matching lines @@
     if (info.Length() > 2) {
         if (RefPtr<LocalFrame> frame = htmlDocument->frame()) {
             // Fetch the global object for the frame.
             v8::Local<v8::Context> context = toV8Context(info.GetIsolate(), frame.get(), DOMWrapperWorld::current(info.GetIsolate()));
             // Bail out if we cannot get the context.
             if (context.IsEmpty())
                 return;
             v8::Local<v8::Object> global = context->Global();
             // Get the open property of the global object.
             v8::Local<v8::Value> function = global->Get(v8AtomicString(info.GetIsolate(), "open"));
+            // Failed; return without throwing (new) exception.
+            if (function.IsEmpty())
+                return;
             // If the open property is not a function throw a type error.
             if (!function->IsFunction()) {
                 throwTypeError("open is not a function", info.GetIsolate());
                 return;
             }
             // Wrap up the arguments and call the function.
             OwnPtr<v8::Local<v8::Value>[]> params = adoptArrayPtr(new v8::Local<v8::Value>[info.Length()]);
             for (int i = 0; i < info.Length(); i++)
                 params[i] = info[i];
 
             v8SetReturnValue(info, frame->script().callFunction(v8::Local<v8::Function>::Cast(function), global, info.Length(), params.get()));
             return;
         }
     }
 
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "open", "Document", info.Holder(), info.GetIsolate());
     htmlDocument->open(callingDOMWindow(info.GetIsolate())->document(), exceptionState);
     if (exceptionState.throwIfNeeded())
         return;
 
     v8SetReturnValue(info, info.Holder());
 }
 
 } // namespace WebCore