Fix the reviver function in JSON.parse

src/json.js

 // Copyright 2009 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 $jsonSerializeAdapter;
 
 (function(global, utils) {
 
 "use strict";
 
@@ skipping 17 matching lines @@
 
 // -------------------------------------------------------------------
 
 function Revive(holder, name, reviver) {
   var val = holder[name];
   if (IS_OBJECT(val)) {
     if (IS_ARRAY(val)) {
       var length = val.length;
       for (var i = 0; i < length; i++) {
         var newElement = Revive(val, %_NumberToString(i), reviver);
-        val[i] = newElement;
+        if (IS_UNDEFINED(newElement)) {
+          delete val[i];
+        } else {
+          val[i] = newElement;
+        }
       }
     } else {
       for (var p in val) {
         if (HAS_OWN_PROPERTY(val, p)) {
           var newElement = Revive(val, p, reviver);
           if (IS_UNDEFINED(newElement)) {
             delete val[p];
           } else {
             val[p] = newElement;
           }
@@ skipping 196 matching lines @@
 // JSON Builtins
 
 $jsonSerializeAdapter = function(key, object) {
   var holder = {};
   holder[key] = object;
   // No need to pass the actual holder since there is no replacer function.
   return JSONSerialize(key, holder, UNDEFINED, new InternalArray(), "", "");
 }
 
 })