del_trailing_separator

# File ext/pathname/lib/pathname.rb, line 143
  def del_trailing_separator(path)
    if r = chop_basename(path)
      pre, basename = r
      pre + basename
    elsif /#{SEPARATOR_PAT}+\z/ =~ path
      $` + File.dirname(path)[/#{SEPARATOR_PAT}*\z/]
    else
      path
    end
  end