Add EscapableHandleScope to api to fix problems with HandleScope::Close

src/api.cc

 // Copyright 2012 the V8 project authors. 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
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 683 matching lines @@
 }
 
 
 i::Object** HandleScope::CreateHandle(i::HeapObject* value) {
   ASSERT(value->IsHeapObject());
   return reinterpret_cast<i::Object**>(
       i::HandleScope::CreateHandle(value->GetIsolate(), value));
 }
 
 
+EscapableHandleScope::EscapableHandleScope(Isolate* v8_isolate) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  escape_slot_ = CreateHandle(isolate, isolate->heap()->the_hole_value());
+  Initialize(v8_isolate);
+}
+
+
+i::Object** EscapableHandleScope::Escape(i::Object** escape_value) {
+  ApiCheck(*escape_slot_ == isolate_->heap()->the_hole_value(),
+           "EscapeableHandleScope::Escape",
+           "Escape value set twice");
+  if (escape_value == NULL) {
+    *escape_slot_ = isolate_->heap()->undefined_value();
+    return NULL;
+  }
+  *escape_slot_ = *escape_value;
+  return escape_slot_;
+}
+
+
 void Context::Enter() {
   i::Handle<i::Context> env = Utils::OpenHandle(this);
   i::Isolate* isolate = env->GetIsolate();
   ENTER_V8(isolate);
   isolate->handle_scope_implementer()->EnterContext(env);
   isolate->handle_scope_implementer()->SaveContext(isolate->context());
   isolate->set_context(*env);
 }
 
 
@@ skipping 6846 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal