    # File lib/chef/cookbook_version.rb, line 658
        def preferred_filename_on_disk_location(node, segment, filename, current_filepath=nil)
          manifest_record = preferred_manifest_record(node, segment, filename)
          if current_filepath && (manifest_record['checksum'] == self.class.checksum_cookbook_file(current_filepath))
            nil
          else
            file_vendor.get_filename(manifest_record['path'])
          end
        end