Improved JSON stringify.

src/json.js

 // Copyright 2009 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 187 matching lines @@
 
 function BasicSerializeArray(value, stack, builder) {
   if (StackContains(stack, value)) {
     throw MakeTypeError('circular_structure', []);
   }
   stack.push(value);
   builder.push("[");
   var len = value.length;
   for (var i = 0; i < len; i++) {
     var before = builder.length;
-    BasicJSONSerialize($String(i), value, stack, builder);
+    BasicJSONSerialize(i, value, stack, builder);
     if (before == builder.length) builder.push("null");
     builder.push(",");
   }
   stack.pop();
   if (builder.pop() != ",") {
     builder.push("[]");  // Zero length array. Push "[" back on.
   } else {
     builder.push("]");
   }
 
 }
 
 
 function BasicSerializeObject(value, stack, builder) {
   if (StackContains(stack, value)) {
     throw MakeTypeError('circular_structure', []);
   }
   stack.push(value);
   builder.push("{");
   for (var p in value) {
-    if (ObjectHasOwnProperty.call(value, p)) {
-      builder.push(%QuoteJSONString(p), ":");
+    if (%HasLocalProperty(value, p)) {
+      builder.push(%QuoteJSONString(p));
+      builder.push(":");
       var before = builder.length;
       BasicJSONSerialize(p, value, stack, builder);
       if (before == builder.length) {
         builder.pop();
         builder.pop();
       } else {
         builder.push(",");
       }
     }
   }
   stack.pop();
   if (builder.pop() != ",") {
     builder.push("{}");  // Object has no own properties. Push "{" back on.
   } else {
     builder.push("}");
   }
 }
 
 
 function BasicJSONSerialize(key, holder, stack, builder) {
   var value = holder[key];
   if (IS_OBJECT(value) && value) {
     var toJSON = value.toJSON;
-    if (IS_FUNCTION(toJSON)) value = toJSON.call(value, key);
+    if (IS_FUNCTION(toJSON)) value = toJSON.call(value, $String(key));
   }
   if (IS_STRING(value)) {
     builder.push(%QuoteJSONString(value));
   } else if (IS_NUMBER(value)) {
     builder.push(($isFinite(value) ? %_NumberToString(value) : "null"));
   } else if (IS_BOOLEAN(value)) {
     builder.push((value ? "true" : "false"));
   } else if (IS_OBJECT(value)) {
     // Unwrap value if necessary
     if (IS_NUMBER_WRAPPER(value)) {
@@ skipping 53 matching lines @@
 }
 
 function SetupJSON() {
   InstallFunctions($JSON, DONT_ENUM, $Array(
     "parse", JSONParse,
     "stringify", JSONStringify
   ));
 }
 
 SetupJSON();