Ensure CreateDataProperty works correctly on TypedArrays

src/objects.cc

 // Copyright 2015 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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 6670 matching lines @@
 
 Maybe<bool> JSObject::CreateDataProperty(LookupIterator* it,
                                          Handle<Object> value,
                                          ShouldThrow should_throw) {
   DCHECK(it->GetReceiver()->IsJSObject());
   MAYBE_RETURN(JSReceiver::GetPropertyAttributes(it), Nothing<bool>());
   Handle<JSReceiver> receiver = Handle<JSReceiver>::cast(it->GetReceiver());
   Isolate* isolate = receiver->GetIsolate();
 
   if (it->IsFound()) {
-    if (!it->IsConfigurable()) {
+    if (it->state() == LookupIterator::INTEGER_INDEXED_EXOTIC ||

[adamk, 2016/03/21 21:44:01]

Why is this needed? DefineOwnPropertyIgnoreAttributes looks like it already
handles this state, and calls RedefineIncompatibleProperty(), which throws the
same TypeError.

[Dan Ehrenberg, 2016/03/21 22:08:43]

If there isn't a check here, then IsConfigurable() throws because
INTEGER_INDEXED_EXOTIC doesn't have property_details_.

[Toon Verwaest, 2016/03/31 15:08:03]

IsConfigurable should not be exposed at all. You need to call
GetPropertyAttributes(it) in case of IsFound() to get to the actual attributes.
The cached property_details_ are only valid for data properties on the object;
not for INTERCEPTOR, ACCESS_CHECK, INTEGER_INDEXED_EXOTIC. For INTEGER_INDEXED
this will claim ABSENT, but that's fine since DefineOwnPropertyIgnoreAttributes
throws the correct error as Adam mentioned.

[Dan Ehrenberg, 2016/04/04 23:48:06]

I guess all of those cases could actually come up in concat, as a species
constructor can return anything. What do you think of the new patch?

+        !it->IsConfigurable()) {
       RETURN_FAILURE(
           isolate, should_throw,
           NewTypeError(MessageTemplate::kRedefineDisallowed, it->GetName()));
     }
   } else {
     if (!JSObject::IsExtensible(Handle<JSObject>::cast(it->GetReceiver()))) {
       RETURN_FAILURE(
           isolate, should_throw,
           NewTypeError(MessageTemplate::kDefineDisallowed, it->GetName()));
     }
@@ skipping 13046 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8