[NaCl SDK] nacl_io: Fix use-after-free bug in html5fs

native_client_sdk/src/libraries/nacl_io/html5fs/html5_fs.cc

 // Copyright 2013 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 "nacl_io/html5fs/html5_fs.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 27 matching lines @@
   }
   return hash;
 }
 
 ino_t Html5Fs::HashPath(const Path& path) {
   // Prime the DJB2a hash
   ino_t hash = 5381;
 
   // Apply a running DJB2a to each part of the path
   for (size_t segment = 0; segment < path.Size(); segment++) {
-    const char *ptr = path.Part(segment).c_str();
-    size_t len = path.Part(segment).length();
-    hash = HashPathSegment(hash, ptr, len);
+    const std::string& part = path.Part(segment);
+    hash = HashPathSegment(hash, part.c_str(), part.length());
   }
   return hash;
 }
 
 
 // For HTML5, the INO should be the one used by the system, however PPAPI
 // does not provide access to the real INO.  Instead, since HTML5 does not
 // suport links, we assume that files are unique based on path to the base
 // of the mount.
 void Html5Fs::OnNodeCreated(Node* node) {
@@ skipping 278 matching lines @@
 }
 
 void Html5Fs::FilesystemOpenCallback(int32_t result) {
   AUTO_LOCK(filesysem_open_lock_);
   filesystem_open_has_result_ = true;
   filesystem_open_error_ = PPErrorToErrno(result);
   pthread_cond_signal(&filesystem_open_cond_);
 }
 
 }  // namespace nacl_io