[proxies] Fix JSObject::AllCanRead for Proxies on the prototype chain

src/objects.cc

 // Copyright 2013 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 1170 matching lines @@
   DCHECK(it->state() == LookupIterator::ACCESS_CHECK ||
          it->state() == LookupIterator::INTERCEPTOR);
   for (it->Next(); it->IsFound(); it->Next()) {
     if (it->state() == LookupIterator::ACCESSOR) {
       auto accessors = it->GetAccessors();
       if (accessors->IsAccessorInfo()) {
         if (AccessorInfo::cast(*accessors)->all_can_read()) return true;
       }
     } else if (it->state() == LookupIterator::INTERCEPTOR) {
       if (it->GetInterceptor()->all_can_read()) return true;
+    } else if (it->state() == LookupIterator::JSPROXY) {
+      // Stop lookupiterating. And no, AllCanNotRead.

[Jakob Kummerow, 2015/12/11 14:52:28]

Do you like this comment, or is it too friday?

+      return false;
     }
   }
   return false;
 }
 
 
 MaybeHandle<Object> JSObject::GetPropertyWithFailedAccessCheck(
     LookupIterator* it) {
   Handle<JSObject> checked = it->GetHolder<JSObject>();
   while (AllCanRead(it)) {
@@ skipping 18049 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