shift_path_info

# File lib/webrick/httpservlet/filehandler.rb, line 299
      def shift_path_info(req, res, path_info, base=nil)
        tmp = path_info.shift
        base = base || tmp
        req.path_info = path_info.join
        req.script_name << base
        res.filename = File.expand_path(res.filename + base)
        check_filename(req, res, File.basename(res.filename))
      end