Add an ASSERT about cross-world wrapper leakage into ScriptValue

Source/bindings/v8/ScriptValue.cpp

 /*
  * Copyright (C) 2008, 2009, 2011 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 23 matching lines @@
 #include "bindings/v8/ScriptState.h"
 #include "bindings/v8/V8Binding.h"
 #include "platform/JSONValues.h"
 
 namespace WebCore {
 
 ScriptValue::~ScriptValue()
 {
 }
 
+v8::Handle<v8::Value> ScriptValue::v8Value() const
+{
+    if (isEmpty())
+        return v8::Handle<v8::Value>();
+
+    ASSERT(isolate()->InContext());
+
+    // This is a check to validate that you don't return a ScriptValue to a world different
+    // from the world that created the ScriptValue.
+    // Probably this could be:
+    //   if (&m_scriptState->world() == &DOMWrapperWorld::current(isolate()))
+    //       return v8::Handle<v8::Value>();
+    // instead of triggering RELEASE_ASSERT.
+    RELEASE_ASSERT(&m_scriptState->world() == &DOMWrapperWorld::current(isolate()));
+    return m_value->newLocal(isolate());
+}
+
 bool ScriptValue::toString(String& result) const
 {
     if (isEmpty())
         return false;
 
-    v8::HandleScope handleScope(isolate());
+    ScriptState::Scope scope(m_scriptState.get());
     v8::Handle<v8::Value> string = v8Value();
     if (string.IsEmpty() || !string->IsString())
         return false;
     result = toCoreString(v8::Handle<v8::String>::Cast(string));
     return true;
 }
 
 PassRefPtr<JSONValue> ScriptValue::toJSONValue(ScriptState* scriptState) const
 {
     ASSERT(!scriptState->contextIsEmpty());
     ScriptState::Scope scope(scriptState);
     return v8ToJSONValue(scriptState->isolate(), v8Value(), JSONValue::maxDepth);
 }
 
 } // namespace WebCore