ietf-nntp Issue: empty groups

[Jack De Winter]

>I'm not convinced that it's confusing or a problem. In all cases where the
>server bothers indicating that the group is empty, the count should be zero.
>If the count is non-zero, the response should be handled as for any other
>normal response. Setting first=last=0 omits some information which could
>be of use to the client, but the equivalent information will become
>available the next time the client looks when the group isn't empty (and
>waiting until then could actually avoid some special-case processing).
>
>The discussion really centred around what meaning, if any, could safely be
>attributed to the low and high article numbers when the count is zero. My
>interpretation of the discussion so far is that in all the cases which are 
>believed to arise in reality, if the high article number is non-zero (when
>the count is zero) then it will be the highest article number assigned so
>far in the group, and can be used (for example) to mark all articles up to
>and including that one as read. If it's zero, it should simply be ignored 
>and the articles can be marked as read by reference to the low article 
>number seen in the next response for that group which has a non-zero count.
>(And doing that in all cases, never doing it for count=0, actually 
>simplifies things for the client by avoiding some special-case handling.)
>
>The low article number provides no useful information for the client when
>the count is zero.

Possibly in your case.  I might decide (in a polling situation) that I
want to add a check to make sure that my polling time is not too large
and that I am not missing articles.  With the 0 0 0 approach, this would
be impossible.  I would have no simple way of deducing if I have missed
any articles.

With any of the other approaches, I can see if maybe I need to increase
the poll time, because I am indeed missing articles.  I would get
first1 = 5, last1 = 4, count = 0, and then the next time first2 = 6,
last2 = 5, count = 0.  I know a lot of people that want to use polling
mechanisms simply because they do not want to waste tonnes of space
and bandwidth accepting alt.fish.go and would rather poll for what they
want instead of getting a big dump.

regards,
Jack
-------------------------------------------------
Jack De Winter - Wildbear Consulting, Inc.
(519) 576-3873		http://www.wildbear.on.ca/

Author of SLMail(95/NT) (http://www.seattlelab.com/) and other great products.