html_yadis_location (OpenID::Yadis)

    # File lib/openid/yadis/parsehtml.rb, line 6
        def Yadis.html_yadis_location(html)
          parser = HTMLTokenizer.new(html)

          # to keep track of whether or not we are in the head element
          in_head = false

          begin
            while el = parser.getTag('head', '/head', 'meta', 'body', '/body',
                                     'html', 'script')

              # we are leaving head or have reached body, so we bail
              return nil if ['/head', 'body', '/body'].member?(el.tag_name)

              if el.tag_name == 'head'
                unless el.to_s[-2] == ?/ # tag ends with a /: a short tag
                  in_head = true
                end
              end
              next unless in_head

              if el.tag_name == 'script'
                unless el.to_s[-2] == ?/ # tag ends with a /: a short tag
                  parser.getTag('/script')
                end
              end

              return nil if el.tag_name == 'html'

              if el.tag_name == 'meta' and (equiv = el.attr_hash['http-equiv'])
                if ['x-xrds-location','x-yadis-location'].member?(equiv.downcase) &&
                    el.attr_hash.member?('content')
                  return CGI::unescapeHTML(el.attr_hash['content'])
                end
              end
            end
          rescue HTMLTokenizerError # just stop parsing if there's an error
          end
        end