Do not silently drop \u0000 in base::JSONReader

base/json/json_parser.cc

 // Copyright (c) 2012 The Chromium 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 "base/json/json_parser.h"
 
 #include <cmath>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 631 matching lines @@
     CBU8_APPEND_UNSAFE(code_unit8, offset, code_point);
   } else {
     // Not a surrogate.
     DCHECK(CBU16_IS_SINGLE(code_unit16_high));
     if (!IsValidCharacter(code_unit16_high))
       return false;
 
     CBU8_APPEND_UNSAFE(code_unit8, offset, code_unit16_high);
   }
 
-  dest_string->append(code_unit8);
+  dest_string->append(code_unit8, offset);
   return true;
 }
 
 void JSONParser::DecodeUTF8(const int32_t& point, StringBuilder* dest) {
   DCHECK(IsValidCharacter(point));
 
   // Anything outside of the basic ASCII plane will need to be decoded from
   // int32_t to a multi-byte sequence.
   if (point < kExtendedASCIIStart) {
     dest->Append(static_cast<char>(point));
@@ skipping 167 matching lines @@
                                            const std::string& description) {
   if (line || column) {
     return StringPrintf("Line: %i, column: %i, %s",
         line, column, description.c_str());
   }
   return description;
 }
 
 }  // namespace internal
 }  // namespace base