class ActionDispatch::FileHandler

def each_candidate_filepath(path_info)
  return unless path = clean_path(path_info)
  ext = ::File.extname(path)
  content_type = ::Rack::Mime.mime_type(ext, nil)
  yield path, content_type || "text/plain"
  # Tack on .html and /index.html only for paths that don't have
  # an explicit, resolvable file extension. No need to check
  # for foo.js.html and foo.js/index.html.
  unless content_type
    default_ext = ::ActionController::Base.default_static_extension
    if ext != default_ext
      default_content_type = ::Rack::Mime.mime_type(default_ext, "text/plain")
      yield "#{path}#{default_ext}", default_content_type
      yield "#{path}/#{@index}#{default_ext}", default_content_type
    end
  end
  nil
end