Bug in topic

[Katsumi Yamaoka <yamaoka@jpl.org>]

Hi,

Someone reported in the Semi-gnus list that setting the
`gnus-topic-display-empty-topics' variable to nil is quite
dangerous.

Assume that there are two topics.  One is named "keep", the
other is for spam articles named "junk", and the topic parameter
for the "junk" topic contains `(total-expire . t)'.  The groups
will be displayed in the Group buffer as follows when a user
types the `L' key:

[ Gnus -- 5 ]
  [ keep -- 5 ]
         5: nnml:foo
  [ junk -- 0 ]
         0: nnml:spam

However, the "junk" topic is not displayed in the Group buffer
normally since `gnus-topic-display-empty-topics' is nil and there
is no unread article.  Then, if a user types `j nnml:spam RET',
the "spam" group will appear in the Group buffer as follows:

[ Gnus -- 5 ]
  [ keep -- 5 ]
  [ junk -- 0 ]
         0: nnml:spam
         5: nnml:foo

The reason why it is dangerous is that the articles contained in
the nnml:foo group will be expired immediately after reading
them.  Persons well informed in gnus-topic.el can solve this
problem easily, can't you? ;-)
-- 
Katsumi Yamaoka <yamaoka@jpl.org>