Cross-script variables handling fixed. It was possible to write to read-only global variable.

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 <iomanip>
 #include <sstream>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 15869 matching lines @@
 
 
 void PropertyCell::UpdateCell(Handle<GlobalDictionary> dictionary, int entry,
                               Handle<Object> value, PropertyDetails details) {
   DCHECK(!value->IsTheHole());
   DCHECK(dictionary->ValueAt(entry)->IsPropertyCell());
   Handle<PropertyCell> cell(PropertyCell::cast(dictionary->ValueAt(entry)));
   const PropertyDetails original_details = cell->property_details();
   // Data accesses could be cached in ics or optimized code.
   bool invalidate =
-      original_details.kind() == kData && details.kind() == kAccessor;
+      (original_details.kind() == kData && details.kind() == kAccessor) ||
+      ((original_details.attributes() & READ_ONLY) !=
+       (details.attributes() & READ_ONLY));
   int index = original_details.dictionary_index();
   PropertyCellType old_type = original_details.cell_type();
   // Preserve the enumeration index unless the property was deleted or never
   // initialized.
   if (cell->value()->IsTheHole()) {
     index = dictionary->NextEnumerationIndex();
     dictionary->SetNextEnumerationIndex(index + 1);
     // Negative lookup cells must be invalidated.
     invalidate = true;
   }
@@ skipping 22 matching lines @@
                                             Handle<Object> new_value) {
   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