Path: utzoo!censor!geac!alias!imax!dave
From: dave@imax.uucp (Dave Martindale)
Newsgroups: news.software.b
Subject: Re: RN bug -- throws away unread articles
Message-ID: <1990Apr12.170518.8603@imax.uucp>
Date: 12 Apr 90 17:05:18 GMT
References: <34104@shemp.CS.UCLA.EDU>
Reply-To: dave@imax.com (Dave Martindale)
Organization: Imax Systems Corporation, Oakville Ontario
Lines: 32

In article <34104@shemp.CS.UCLA.EDU> wales@valeria.cs.ucla.edu (Rich Wales) writes:
>For some time now, we (UCLA CS Dept.) have been plagued by an RN bug
>that -- under circumstances not clearly understood -- marks articles
>as read which have not in fact been read.
>
>This happens in the course of ordinary reading of articles in a news-
>group via "^N".  It usually (always?) occurs in conjunction with the
>"Skipping..." message from RN.  One minute, there may be several dozen
>(or even several hundred) unread articles in a newsgroup; the next
>thing the user knows, there are only a few unread articles, or even
>none at all.

This *will* occur, and is perfectly normal, if articles expire before
you've read them.

When you select a group, rn looks at what articles you've
already read (according to the .newsrc) and declares the rest of
them to be "unread".  Then, when you start reading, rn may find that
many of those articles do not exist, thus the "skipping" message.
When rn finally finds a "next article" that is really present,
you may find that it has revised its idea of how many articles
remain to be read.  The "lost" articles were unread by that user,
but do not exist locally, so rn marks them read.

Now, the "active" file contains a field that tells you the lowest
article number still present, and this may modify rn's idea of the
lowest possible unread article.  But C news sites don't necessarily
update the active file as frequently as they expire articles.
And, in any case, one particular article with a far-future
explicit expiry date will cause the "lowest unexpired article"
field to stay static while hundreds of articles after it have
expired.