bug#22786: 25.1.50; eww arabic rendering

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: mohamed.hibti@gmail.com,  22786@debbugs.gnu.org
> Date: Tue, 01 Mar 2016 10:56:38 +1100
> 
> > So I think for best results we should add support for the remaining
> > bidi directives.  Adding support for "dir=auto" in the HTML tag is
> > almost trivial.  To support the rest of the directives you need to add
> > bidirectional formatting control characters before and/or around the
> > text that is marked with these directives.  (If needed, I can provide
> > the details about the controls you need to insert in each case.)
> 
> I think I remember the control characters from past discussions.  But is
> the dir attribute used much in practice?  I've tried to be very, very
> restrictive in what features I add to the common paths in shr.  It's
> already slow enough, and each new line of code in the common paths add
> some slow down.  It's death by a thousand cuts.  :-) I don't oppose
> adding support for this if it's really used a lot in the wild, but if
> not, I'd rather not.

I don't have any statistics.  I would expect it to be used in pages
that show paragraphs of different direction.

> (The "dir" attribute can apply to (almost) any HTML element, so the code
> to detect and react to it would go into `shr-descend', which is called
> once for every single HTML node in the document.)

Can you add its support to the <p> element?  I think this will go a
long way towards supporting the majority of use cases.

Thanks.