Fixes issue 712 causing non-configurable accessors to be overwritable by usin...

src/v8natives.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 416 matching lines @@
   this.writable_ = writable;
   this.hasWritable_ = true;
 }
 
 
 PropertyDescriptor.prototype.isWritable = function() {
   return this.writable_;
 }
 
 
+PropertyDescriptor.prototype.hasWritable = function() {
+  return this.hasWritable_;
+}
+
+
 PropertyDescriptor.prototype.setConfigurable = function(configurable) {
   this.configurable_ = configurable;
   this.hasConfigurable_ = true;
 }
 
 
 PropertyDescriptor.prototype.hasConfigurable = function() {
   return this.hasConfigurable_;
 }
 
@@ skipping 83 matching lines @@
 function DefineOwnProperty(obj, p, desc, should_throw) {
   var current = GetOwnProperty(obj, p);
   var extensible = %IsExtensible(ToObject(obj));
 
   // Error handling according to spec.
   // Step 3
   if (IS_UNDEFINED(current) && !extensible)
     throw MakeTypeError("define_disallowed", ["defineProperty"]);
 
   if (!IS_UNDEFINED(current) && !current.isConfigurable()) {
+      // Step 5 and 6
+     if ((!desc.hasEnumerable() || 
+          SameValue(desc.isEnumerable() && current.isEnumerable())) &&
+         (!desc.hasConfigurable() || 
+          SameValue(desc.isConfigurable(), current.isConfigurable())) &&
+         (!desc.hasWritable() || 
+          SameValue(desc.isWritable(), current.isWritable())) &&
+         (!desc.hasValue() ||
+          SameValue(desc.getValue(), current.getValue())) &&
+         (!desc.hasGetter() ||
+          SameValue(desc.getGet(), current.getGet())) &&
+         (!desc.hasSetter() ||
+          SameValue(desc.getSet(), current.getSet()))) {
+       return true;
+     }
+                        
     // Step 7
     if (desc.isConfigurable() ||  desc.isEnumerable() != current.isEnumerable())
       throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
     // Step 9
     if (IsDataDescriptor(current) != IsDataDescriptor(desc))
       throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
     // Step 10
     if (IsDataDescriptor(current) && IsDataDescriptor(desc)) {
       if (!current.isWritable() && desc.isWritable())
         throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
@@ skipping 116 matching lines @@
   var obj = new $Object();
   obj.__proto__ = proto;
   if (!IS_UNDEFINED(properties)) ObjectDefineProperties(obj, properties);
   return obj;
 }
 
 
 // ES5 section 15.2.3.6.
 function ObjectDefineProperty(obj, p, attributes) {
   if ((!IS_SPEC_OBJECT_OR_NULL(obj) || IS_NULL_OR_UNDEFINED(obj)) &&
-      !IS_UNDETECTABLE(obj))
+      !IS_UNDETECTABLE(obj)) {
     throw MakeTypeError("obj_ctor_property_non_object", ["defineProperty"]);
+  }
   var name = ToString(p);
   var desc = ToPropertyDescriptor(attributes);
   DefineOwnProperty(obj, name, desc, true);
   return obj;
 }
 
 
 // ES5 section 15.2.3.7.
 function ObjectDefineProperties(obj, properties) {
  if ((!IS_SPEC_OBJECT_OR_NULL(obj) || IS_NULL_OR_UNDEFINED(obj)) &&
@@ skipping 314 matching lines @@
 
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();