Charles Lindsey wrote:
In <416709CF(_dot_)1080701(_at_)erols(_dot_)com> Bruce Lilly
<blilly(_at_)erols(_dot_)com> writes:
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.
No Charles, this is not merely "possible scenarios". It is about
the very real situation of comparing identifiers. Either a case-
sensitive or a case-insensitive comparison could be made; one
must decide which. Under RFC 822 and its predecessors, where the
RHS of an identifier was always a domain name, the correct
decision is to compare those domain names case-insensitively. The
change in RFC 2822 -- where we are told that the RHS might or
might not be a domain name, and if it is not, we are not told
whether or not it is case-sensitive -- makes that decision
more difficult. It is an issue of the design of such a
comparator, irrespective of the source of the identifiers.