add a default value for return value

test/cctest/test-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 792 matching lines @@
 }
 
 
 template<typename T>
 static void CheckReturnValue(const T& t) {
   v8::ReturnValue<v8::Value> rv = t.GetReturnValue();
   i::Object** o = *reinterpret_cast<i::Object***>(&rv);
   CHECK_EQ(v8::Isolate::GetCurrent(), t.GetIsolate());
   CHECK_EQ(t.GetIsolate(), rv.GetIsolate());
   CHECK((*o)->IsTheHole() || (*o)->IsUndefined());
+  // Verify reset
+  bool is_runtime = (*o)->IsTheHole();
+  rv.Set(true);
+  CHECK(!(*o)->IsTheHole() && !(*o)->IsUndefined());
+  rv.Set(v8::Handle<v8::Object>());
+  CHECK((*o)->IsTheHole() || (*o)->IsUndefined());
+  CHECK_EQ(is_runtime, (*o)->IsTheHole());
 }
 
 static v8::Handle<Value> handle_call(const v8::Arguments& args) {
   ApiTestFuzzer::Fuzz();
   CheckReturnValue(args);
   args.GetReturnValue().Set(v8_str("bad value"));
   return v8_num(102);
 }
 
 static v8::Handle<Value> handle_call_2(const v8::Arguments& args) {
@@ skipping 18499 matching lines @@
   i::Semaphore* sem_;
   volatile int sem_value_;
 };
 
 
 THREADED_TEST(SemaphoreInterruption) {
   ThreadInterruptTest().RunTest();
 }
 
 #endif  // WIN32