# File lib/rubygems/remote_fetcher.rb, line 233
  def open_uri_or_path(uri, last_modified = nil, head = false, depth = 0)
    raise "block is dead" if block_given?

    return open(get_file_uri_path(uri)) if file_uri? uri

    uri = URI.parse uri unless URI::Generic === uri
    raise ArgumentError, 'uri is not an HTTP URI' unless URI::HTTP === uri

    fetch_type = head ? Net::HTTP::Head : Net::HTTP::Get
    response   = request uri, fetch_type, last_modified

    case response
    when Net::HTTPOK, Net::HTTPNotModified then
      head ? response : response.body
    when Net::HTTPMovedPermanently, Net::HTTPFound, Net::HTTPSeeOther,
         Net::HTTPTemporaryRedirect then
      raise FetchError.new('too many redirects', uri) if depth > 10

      open_uri_or_path(response['Location'], last_modified, head, depth + 1)
    else
      raise FetchError.new("bad response #{response.message} #{response.code}", uri)
    end
  end