Confusion on changing data property callback attributes

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index df70d5c5f8865025004c1f07f08f94298516068c..9c344233584d6f38dae574a61946211c8978ea67 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -2004,6 +2004,27 @@ THREADED_TEST(EmptyInterceptorDoesNotShadowAccessors) {
 }
 
 
+THREADED_TEST(ExecutableAccessorIsPreservedOnAttributeChange) {
+  v8::Isolate* isolate = CcTest::isolate();
+  v8::HandleScope scope(isolate);
+  LocalContext env;
+  v8::Local<v8::Value> res = CompileRun("var a = []; a;");
+  i::Handle<i::JSObject> a(v8::Utils::OpenHandle(v8::Object::Cast(*res)));
+  CHECK(a->map()->instance_descriptors()->IsFixedArray());
+  CHECK_GT(i::FixedArray::cast(a->map()->instance_descriptors())->length(), 0);
+  CompileRun("Object.defineProperty(a, 'length', { writable: false });");
+  CHECK_EQ(i::FixedArray::cast(a->map()->instance_descriptors())->length(), 0);
+  // But we should still have an ExecutableAccessorInfo.
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  i::LookupResult lookup(i_isolate);
+  i::Handle<i::String> name(v8::Utils::OpenHandle(*v8_str("length")));
+  a->LocalLookupRealNamedProperty(name, &lookup);
+  CHECK(lookup.IsPropertyCallbacks());
+  i::Handle<i::Object> callback(lookup.GetCallbackObject(), i_isolate);
+  CHECK(callback->IsExecutableAccessorInfo());
+}
+
+
 THREADED_TEST(EmptyInterceptorBreakTransitions) {
   v8::HandleScope scope(CcTest::isolate());
   Handle<FunctionTemplate> templ = FunctionTemplate::New(CcTest::isolate());