summary shows R2L

["السّلام عليكم" <yamaoka@jpl.org>]

السّلام عليكم (Hello),

You will see the summary buffer is drawn right to left if:
 - You use Emacs 24.
 - The subject of this article is at the beginning of the summary
   buffer.
 - The summary line of this article has no mark, i.e., begins with
   a space.

If you don't see it so, try setting `gnus-summary-line-format' to
the default value ("%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n").

I found this today in a trash folder.  The other summary lines
are also drawn right to left even if those are English messages.
So, I added this snippet as a workaround:

(add-hook 'gnus-summary-mode-hook
	  (lambda ()
	    (setq bidi-paragraph-direction 'left-to-right)))

I think it worth making Gnus do it by default.  WDYT?
In addition, I also tried the next one:

(add-hook 'gnus-article-mode-hook
	  (lambda ()
	    (setq bidi-paragraph-direction 'left-to-right)))

But I couldn't see whether it is worthwhile or not, since I'm not
familiar with R2L text.