Re: Unicode confusables and reordering characters considered harmful

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Kangas <stefankangas@gmail.com>
> Date: Tue, 2 Nov 2021 12:26:29 -0700
> Cc: cpitclaudel@gmail.com, emacs-devel@gnu.org
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > You cannot see those characters on a screenshot, for the same reason
> > you cannot see any whitespace characters on a screenshot: they are
> > only discernible when you move cursor through them.  Which is why I
> > asked how are you looking for them.  If you are looking for them in a
> > screenshot, you will never see them.
> 
> Now I see what you mean.  Yes, they are clearly "visible" when you move
> the cursor through them, in the sense that the cursor will jump.

Not only will it jump, it will display as a thin 1-pixel shape when
point is at the position of these control characters.  Just move it
slowly so as not to miss that.

> (Does this not happen in other text editors?)

It should, because almost all (if not all) editors provide "logical"
(as opposed to "visual") cursor motion as the default.  The paper
mentions (and dismisses) that.

> Could we add some additional visual indication or warning for such
> characters, in the light of this discussion?

That was why I wrote bidi-find-overridden-directionality several years
ago.  My opinion about this should be clear to you from that fact
alone.  That function has zero uses.  What does this tell you about
the _real_ importance of this kind of problems in people's eyes, even
those very people who argued back then we _must_ have a feature like
that?