In <416709CF(_dot_)1080701(_at_)erols(_dot_)com> Bruce Lilly
<blilly(_at_)erols(_dot_)com> writes:
Charles Lindsey wrote:
Yes, I know all that. You have demonstrated that a problem could,
_in_principle_ arise. But my question, which I repeat again and which you
still have not answered, was:
Have you heard of any case where this esoteric change of semantics
actually caused a problem?
That problem does occur for anybody attempting to write any
software which involves comparisons of such identifiers, which
is exactly the situation initially posed by Jacob. A choice
must be made between comparing identifier right-hand sides
as domain names (viz. case-insensitive) or as RFC 2822 id-right
(2822 doesn't say whether that's case-sensitive or not). Under
the circumstances, comparing as case-insensitive domain names
seems the most reasonable course of action; it is consistent
with the 20+ year history of identifier RHS as domain names and
it is consistent with RFC 2822's recommendation to use domain
names.
And yet again you repeat a whole string of possible scenarios, about
which there is no dispute, whilst steadfastly refusing to answer the
question that was asked, which specifically related to "actual" behaviour.
Message identifiers are generated by the agent that creates the message.
The id-right will usually be a domain name, and it may be in UC or LC. They
may get copied during transport, gatewaying, resending, or when creating
References fields for a reply. Various agents may compare them (e.g. when
threading or when eliminating duplicates).
For anything to go wrong, some agent somewhere has to deliberately change
the case of an id-right during a copying operation. If no agent ever does
that, then no problem can ever arise.
Now, please answer me. Do you know of any ACTUAL agent that changes the
case of an id-right when making such a copy?
--
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131 Fax: +44 161 436 6133 Web: http://www.cs.man.ac.uk/~chl
Email: chl(_at_)clerew(_dot_)man(_dot_)ac(_dot_)uk Snail: 5 Clerewood Ave,
CHEADLE, SK8 3JU, U.K.
PGP: 2C15F1A9 Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5