[builtins] don't create keys for undefined property descriptors in O.gOPDs

src/builtins.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/builtins.h"
 
 #include "src/api-arguments.h"
 #include "src/api-natives.h"
 #include "src/api.h"
 #include "src/base/ieee754.h"
@@ skipping 2007 matching lines @@
   Handle<FixedArray> entries;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, entries,
       JSReceiver::GetOwnEntries(receiver, ENUMERABLE_STRINGS));
   return *isolate->factory()->NewJSArrayWithElements(entries);
 }
 
 BUILTIN(ObjectGetOwnPropertyDescriptors) {
   HandleScope scope(isolate);
   Handle<Object> object = args.atOrUndefined(isolate, 1);
-  Handle<Object> undefined = isolate->factory()->undefined_value();
 
   Handle<JSReceiver> receiver;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, receiver,
                                      Object::ToObject(isolate, object));
 
   Handle<FixedArray> keys;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, keys, KeyAccumulator::GetKeys(
                          receiver, KeyCollectionMode::kOwnOnly, ALL_PROPERTIES,
                          GetKeysConversion::kConvertToString));
 
   Handle<JSObject> descriptors =
       isolate->factory()->NewJSObject(isolate->object_function());
 
   for (int i = 0; i < keys->length(); ++i) {
     Handle<Name> key = Handle<Name>::cast(FixedArray::get(*keys, i, isolate));
     PropertyDescriptor descriptor;
     Maybe<bool> did_get_descriptor = JSReceiver::GetOwnPropertyDescriptor(
         isolate, receiver, key, &descriptor);
     MAYBE_RETURN(did_get_descriptor, isolate->heap()->exception());
 
-    Handle<Object> from_descriptor = did_get_descriptor.FromJust()
-                                         ? descriptor.ToObject(isolate)
-                                         : undefined;
+    if (!did_get_descriptor.FromJust()) continue;
+    Handle<Object> from_descriptor = descriptor.ToObject(isolate);
 
     LookupIterator it = LookupIterator::PropertyOrElement(
         isolate, descriptors, key, descriptors, LookupIterator::OWN);
     Maybe<bool> success = JSReceiver::CreateDataProperty(&it, from_descriptor,
                                                          Object::DONT_THROW);
     CHECK(success.FromJust());
   }
 
   return *descriptors;
 }
@@ skipping 4365 matching lines @@
 BUILTIN_LIST_H(DEFINE_BUILTIN_ACCESSOR_H)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 #undef DEFINE_BUILTIN_ACCESSOR_T
 #undef DEFINE_BUILTIN_ACCESSOR_S
 #undef DEFINE_BUILTIN_ACCESSOR_H
 
 }  // namespace internal
 }  // namespace v8