Re: [idn] Debunking the ACE myth

["Adam M. Costello" <amc@cs.berkeley.edu>]

David Hopwood <david.hopwood@zetnet.co.uk> wrote:

> > Of course it's a failure, but it's not an ACE failure, it's an IDN
> > failure.  The exact same failure would happen for any IDN in this
> > scenario regardless of whether ACE existed or not.
>
> No - it works for just-send-UTF8 (which I assume is Dan's point [*]),
> and it also works for ACE + UTF-8 proposals in which either an ACE or
> a UTF-8 name can be passed to the resolver (including IDN-8).

It works iff the old resolver API can resolve names encoded using the
8-bit encoding used by the clipboard when the mailto: URL was copied
from the browser.  Whether the old resolver API can or should do this is
a debatable question whether ACE exists or not.  The operation in this
scenario is going to succeed or fail regardless of whether this name is
represented using ACE or not.  These are what I meant when I said it's
not an ACE failure, but an IDN failure.

> > It's undeniable that ACE is more backward-compatible, and fails in
> > fewer instances, than any 8-bit encoding.
>
> Encodings don't succeed or fail; proposals do.  So, which ACE
> proposal?

I wasn't talking about proposals, I was talking about domain names
encoded one way or another.  Take any situation where an ACE name fails
to work, replace the name with a corresponding 8-bit encoding, and it
still won't work.  But there are many situations where an ACE name
succeeds while an 8-bit name name would fail.  Therefore ACE is a useful
tool to have in your toolbox.  I think you agree, since you advocate a
system (IDN-8) that includes ACE.

> It isn't true in general that proposals using ACE as the primary
> encoding fail in fewer instances than proposals where UTF-8 is
> preferred.

I don't think I've ever advocated an ACE-only approach, or even argued
that ACE should be preferred.  I've merely argued that ACE is a good
thing to have as an option, for interoperating with old protocols and
old software.

> If you count displaying an ACE name to a human user as a failure
> (which I do, although it is less serious than a lookup failure), then
> ACE-only proposals fail in many more cases.

I'd count it as an annoyance or a glitch, but not a failure.  The
primary purpose of a domain name is to identify a network resource and
allow it to be accessed.  Being pretty/memorable/meaningful is very
desirable, but not essential.

AMC