Add support for zero-padded strings to WebMParser.

media/webm/webm_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 "media/webm/webm_parser.h"
 
 // This file contains code to parse WebM file elements. It was created
 // from information in the Matroska spec.
 // http://www.matroska.org/technical/specs/index.html
 // This file contains code for encrypted WebM. Current WebM
@@ skipping 581 matching lines @@
   return size;
 }
 
 static int ParseBinary(const uint8* buf, int size, int id,
                        WebMParserClient* client) {
   return client->OnBinary(id, buf, size) ? size : -1;
 }
 
 static int ParseString(const uint8* buf, int size, int id,
                        WebMParserClient* client) {
-  std::string str(reinterpret_cast<const char*>(buf), size);
+  const uint8* end = static_cast<const uint8*>(memchr(buf, '\0', size));
+  int length = (end != NULL) ? static_cast<int>(end - buf) : size;
+  std::string str(reinterpret_cast<const char*>(buf), length);
   return client->OnString(id, str) ? size : -1;
 }
 
 static int ParseNonListElement(ElementType type, int id, int64 element_size,
                                const uint8* buf, int size,
                                WebMParserClient* client) {
   DCHECK_GE(size, element_size);
 
   int result = -1;
   switch(type) {
@@ skipping 318 matching lines @@
       if (kSegmentIds[i].id_ == id_b)
         return true;
     }
   }
 
   // kWebMIdSegment siblings.
   return ((id_b == kWebMIdSegment) || (id_b == kWebMIdEBMLHeader));
 }
 
 }  // namespace media