Fix breakage from r28097

runtime/bin/directory_macos.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "bin/directory.h"
 
 #include <dirent.h>  // NOLINT
@@ skipping 375 matching lines @@
     // Pattern has overflowed.
     return NULL;
   }
   char* result;
   do {
     result = mkdtemp(path.AsString());
   } while (result == NULL && errno == EINTR);
   if (result == NULL) {
     return NULL;
   }
-  int length = strnlen(path.AsString(), PATH_MAX);
+  int length = strlen(path.AsString());
   result = static_cast<char*>(malloc(length + 1));
   strncpy(result, path.AsString(), length);
   result[length] = '\0';
   return result;
 }
 
 
 bool Directory::Delete(const char* dir_name, bool recursive) {
   if (!recursive) {
     if (File::GetType(dir_name, false) == File::kIsLink &&
@@ skipping 14 matching lines @@
 bool Directory::Rename(const char* path, const char* new_path) {
   ExistsResult exists = Exists(path);
   if (exists != EXISTS) return false;
   return (TEMP_FAILURE_RETRY(rename(path, new_path)) == 0);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)