the gnus-newsgroup-unseen mark is too sticky

[Bill White <billw@wolfram.com>]

(defvar gnus-newsgroup-unseen nil
  "List of unseen articles in the current newsgroup.")

I'm not sure of the philosophy of "unseen" messages, but there is one
instance when this feature doesn't DWIM.  Say I have a Summary buffer
with some unseen messages, which are marked with ".".  I go to one of
these messages and select it, mark it as read, delete it, whatever.
The "." is still there, when it is really no longer "unseen".

Why is this an issue, you ask?  Well, I have code that highlights
unseen messages with a special face:

----------------------------------------------------------------------
(defface gnus-summary-unseen-face
  '((((class color))
     (:foreground "gold" :background "black")))
  "Face used for unseen (.-marked) articles.")

(require 'gnus-sum)
(require 'cl)

(pushnew '((memq (gnus-summary-article-number)
		 gnus-newsgroup-unseen)
	   . gnus-summary-unseen-face)
	 gnus-summary-highlight)
----------------------------------------------------------------------

After I read one of these nicely-colored unseen messages, the "."
mark still lingers so the function that highlights a line thinks it's
still unseen.  

I would expect the "." to disappear so that other highlighting could
take effect after I'm done with the article.  Is this possible?

Cheers -

bw
-- 
Bill White . billw@wolfram.com . http://members.wri.com/billw
"No ma'am, we're musicians."