[strong] Implement per-object restrictions behaviour of property freezing

src/v8natives.js

 // 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.
 
 var $functionSourceString;
 var $globalEval;
 var $objectGetOwnPropertyDescriptor;
 var $toCompletePropertyDescriptor;
 
 (function(global, utils) {
@@ skipping 663 matching lines @@
         // Step 9a
         if (IsDataDescriptor(current) != IsDataDescriptor(desc)) {
           if (should_throw) {
             throw MakeTypeError(kRedefineDisallowed, p);
           } else {
             return false;
           }
         }
         // Step 10a
         if (IsDataDescriptor(current) && IsDataDescriptor(desc)) {
-          if (!current.isWritable() && desc.isWritable()) {
-            if (should_throw) {
-              throw MakeTypeError(kRedefineDisallowed, p);
-            } else {
-              return false;
+          var currentIsWritable = current.isWritable();
+          if (currentIsWritable != desc.isWritable()) {
+            if (!currentIsWritable || IS_STRONG(obj)) {
+              if (should_throw) {
+                throw IS_STRONG(obj) ?
+                  MakeTypeError(kStrongRedefineDisallowed, o, p) :

[rossberg, 2015/05/22 14:15:29]

Nit: style guide wants ? and : each first on the next line, plus indentation by
4

[conradw, 2015/05/27 18:15:45]

Done.

+                  MakeTypeError(kRedefineDisallowed, p)
+              } else {
+                return false;
+              }
             }
           }
-          if (!current.isWritable() && desc.hasValue() &&
+          if (!currentIsWritable && desc.hasValue() &&
               !$sameValue(desc.getValue(), current.getValue())) {
             if (should_throw) {
               throw MakeTypeError(kRedefineDisallowed, p);
             } else {
               return false;
             }
           }
         }
         // Step 11
         if (IsAccessorDescriptor(desc) && IsAccessorDescriptor(current)) {
@@ skipping 1142 matching lines @@
   to.ObjectGetOwnPropertyKeys = ObjectGetOwnPropertyKeys;
   to.ObjectHasOwnProperty = ObjectHasOwnProperty;
   to.ObjectIsFrozen = ObjectIsFrozen;
   to.ObjectIsSealed = ObjectIsSealed;
   to.ObjectToString = ObjectToString;
   to.OwnPropertyKeys = OwnPropertyKeys;
   to.ToNameArray = ToNameArray;
 });
 
 })