Re: Unicode confusables and reordering characters considered harmful

[Eli Zaretskii <eliz@gnu.org>]

> From: Manuel Giraud <manuel@ledu-giraud.fr>
> Cc: gregory@heytings.org,  cpitclaudel@gmail.com,  stefan@marxist.se,
>   monnier@iro.umontreal.ca,  emacs-devel@gnu.org
> Date: Wed, 03 Nov 2021 22:15:50 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Try it on the text of this message.
> >
> >   ‮madam deified kayak‬
> >
> > And then tell me: Who worshiped whom?
> 
> Ok. On this one, bidi-find-overridden-directionality returns a position
> but I get a nil on the Clément's example:
> 
> if access_level != "user‮ ⁦// Check if admin⁩ ⁦" {
> 
> which is the kind of overridden directionality we should have a warning
> on, no?

Did you read the doc string of bidi-find-overridden-directionality,
which explains what kind of overrides it looks for?  I already said
that it will have to be extended to cover the examples from that
paper.  Those examples override the directionality of punctuation
characters.  By contrast, the original intent of this function was to
detect reordering-caused confusions in URLs, where punctuation
characters don't happen, and if they do, they are not the stuff which
malevolent parties want to reorder.