Use LookupIterator for elements in the observed part of DefineAccessor

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 400be3edaebb01269d94481d7b0e7c59c2043e3e..9dfb12e928b11299e6329ea99b56eb51efd6a2ec 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -6402,27 +6402,14 @@ MaybeHandle<Object> JSObject::DefineAccessor(Handle<JSObject> object,
                      !isolate->IsInternallyUsedPropertyName(name);
   bool preexists = false;
   if (is_observed) {
-    if (is_element) {
-      Maybe<bool> maybe = HasOwnElement(object, index);
-      // Workaround for a GCC 4.4.3 bug which leads to "‘preexists’ may be used
-      // uninitialized in this function".
-      if (!maybe.IsJust()) {
-        DCHECK(false);
-        return isolate->factory()->undefined_value();
-      }
-      preexists = maybe.FromJust();
-      if (preexists && GetOwnElementAccessorPair(object, index).is_null()) {
-        old_value =
-            Object::GetElement(isolate, object, index).ToHandleChecked();
-      }
-    } else {
-      LookupIterator it(object, name, LookupIterator::HIDDEN_SKIP_INTERCEPTOR);
-      CHECK(GetPropertyAttributes(&it).IsJust());
-      preexists = it.IsFound();
-      if (preexists && (it.state() == LookupIterator::DATA ||
-                        it.GetAccessors()->IsAccessorInfo())) {
-        old_value = GetProperty(&it).ToHandleChecked();
-      }
+    LookupIterator::Configuration c = LookupIterator::HIDDEN_SKIP_INTERCEPTOR;
+    LookupIterator it = is_element ? LookupIterator(isolate, object, index, c)
+                                   : LookupIterator(object, name, c);
+    CHECK(GetPropertyAttributes(&it).IsJust());

[Jakob Kummerow, 2015/06/11 11:14:28]

I'm not a fan of having a Release-mode CHECK here, but since it's old code, I
guess we can keep it.

+    preexists = it.IsFound();
+    if (preexists && (it.state() == LookupIterator::DATA ||
+                      it.GetAccessors()->IsAccessorInfo())) {
+      old_value = GetProperty(&it).ToHandleChecked();
     }
   }