class ActiveSupport::SafeBuffer

def [](*args)
  if args.size < 2
    super
  else
    if html_safe?
      new_safe_buffer = super
      if new_safe_buffer
        new_safe_buffer.instance_variable_set :@html_safe, true
      end
      new_safe_buffer
    else
      to_str[*args]
    end
  end
end