cleanpath_conservative

# File lib/pathname.rb, line 397
  def cleanpath_conservative
    path = @path
    names = []
    pre = path
    while r = chop_basename(pre)
      pre, base = r
      names.unshift base if base != '.'
    end
    if /#{SEPARATOR_PAT}/o =~ File.basename(pre)
      names.shift while names[0] == '..'
    end
    if names.empty?
      self.class.new(File.dirname(pre))
    else
      if names.last != '..' && File.basename(path) == '.'
        names << '.'
      end
      result = prepend_prefix(pre, File.join(*names))
      if /\A(?:\.|\.\.)\z/ !~ names.last && has_trailing_separator?(path)
        self.class.new(add_trailing_separator(result))
      else
        self.class.new(result)
      end
    end
  end