cleanpath_aggressive

# File lib/pathname.rb, line 350
  def cleanpath_aggressive
    path = @path
    names = []
    pre = path
    while r = chop_basename(pre)
      pre, base = r
      case base
      when '.'
      when '..'
        names.unshift base
      else
        if names[0] == '..'
          names.shift
        else
          names.unshift base
        end
      end
    end
    if /#{SEPARATOR_PAT}/ =~ File.basename(pre)
      names.shift while names[0] == '..'
    end
    self.class.new(prepend_prefix(pre, File.join(*names)))
  end