bug#22786: 25.1.50; eww arabic rendering

[Eli Zaretskii <eliz@gnu.org>]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: mohamed.hibti@gmail.com,  22786@debbugs.gnu.org
> Date: Sun, 28 Feb 2016 14:43:03 +1030
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > But if there's no such hint, and all we have is the text itself, then
> > the UBA determines the paragraph direction from the first strong
> > directional character, and we then keep that direction until the
> > paragraph ends, which is indicated by an empty line.  There's no way
> > around this, it's how the bidirectional display engine works.
> >
> > Specifically, we need a way to distinguish between the list of
> > languages on a Wikipedia page from the Al Jazeera home page.  Can you
> > spot anything in the page sources that will allow such a distinction?
> 
> Nope.  But since Firefox is able to do this, that means that their bidi
> algo is doing something else than what Emacs' bidi algo is doing...
> 
> So we have demonstrated that there is a way around this.  :-)

The way around it is to support frames (or "side bars").  Then each
frame could have its own base paragraph direction.  AFAICT, eww
doesn't support that yet.

> > In any case, I think it will be good to add a "Switch page direction"
> > menu item to EWW on the emacs-25 branch.
> 
> Good idea; I'll all that.

Thanks.