Re: Bidirectional text and URLs

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 06 Dec 2014 07:06:50 -0500
> From: Richard Stallman <rms@gnu.org>
> CC: larsi@gnus.org, emacs-devel@gnu.org
> 
>   > > In principle they might vary, but in practice I think most of them
>   > > will use the characters in the order they appear in the buffer.
> 
>   > That's true, but that still doesn't say how should each application
>   > show that to the user.
> 
> I don't entirely understand what sort of variation you have in mind,
> but I think we should make all such applications handle this
> as uniformly as possible.

The danger in using such obfuscated strings is different in each
application.  That's because each application assigns different
semantics to the various portions of the string, and does different
things with each portion.  IOW, the semantics of these strings depends
on the application, and thus our solution to warn the user about the
dangers is probably going to be different in each case.

Until now we had only one use case: the URL.  For that use case, we
understood the implications, and we now have the infrastructure to
detect the obfuscation.  We still don't know what will the application
using URLs (in this case, eww) want to do to warn the user and ask for
their permission.  One way is to show the "real" URL to the user,
which will automatically solve the obfuscation problem and display the
URL in its "normal" form -- without the need to turn off the bidi
reordering.  Maybe there are other, better ways -- we just need to
wait and see.

And that's just a single application for which we have a use case we
understand quite well.  Other use cases are yet to come.  When they
do, we should analyze them as we did with this one.

It could be that eventually we come to the conclusion you are
proposing now: that we need a way to display some string in its
logical order of characters.  If and when we arrive to such a
conclusion, there will be sufficient weight to it to justify the
change in the code.  We are not there yet, and it is not clear to me
that we will indeed arrive at that conclusion.  We have at least
partial evidence that this might not be required: no other application
out there does this, AFAIK.