Re: master ce63f91025: Add textsec functions for verifying email addresses

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Po Lu <luangruo@yahoo.com>,  emacs-devel@gnu.org
> Date: Thu, 20 Jan 2022 09:47:42 +0100
> 
> It seems save to allow names that pass
> bidi-find-overridden-directionality ...  but is there an off-by-one
> error there?
> 
> It says that this is OK:
> 
>            "Lars Ingebrigtsen\N{LEFT-TO-RIGHT OVERRIDE}"
> 
> But this isn't:
> 
>            "Lars Ingebrigtsen\N{LEFT-TO-RIGHT OVERRIDE}f"
> 
> And both are equally suspicious.

Why do you think the former one is suspicious?  The override there
doesn't affect any character, because there's nothing after it.

bidi-find-overridden-directionality works by looking at
characters which have their directionality affected by the bidi
controls.  It doesn't look at the controls themselves, because those
controls by themselves aren't doing any harm.