# File lib/openid/urinorm.rb, line 9
    def URINorm.urinorm(uri)
      uri = URI.parse(uri)

      raise URI::InvalidURIError.new('no scheme') unless uri.scheme
      uri.scheme = uri.scheme.downcase
      unless ['http','https'].member?(uri.scheme)
        raise URI::InvalidURIError.new('Not an HTTP or HTTPS URI')
      end

      raise URI::InvalidURIError.new('no host') unless uri.host
      uri.host = uri.host.downcase

      uri.path = remove_dot_segments(uri.path)
      uri.path = '/' if uri.path.length == 0

      uri = uri.normalize.to_s
      uri = uri.gsub(PERCENT_ESCAPE_RE) {
        sub = $&[1..2].to_i(16).chr
        reserved(sub) ? $&.upcase : sub
      }

      return uri
    end