[BUG] : non-colored thread with unread mail in it

[Emmanuel <e allaud wanadoo fr>]

	Hi all, (IMPORTANT : This bug is on 1.2.4!! I have no idea if it 
affects CVS)
After having checked my mail (locally because I use fetchmail), I read 
through the new ones (they were JWZ-threaded) and saw this problem : there 
was a collapsed thread in the "normal" color (ie "no unread mails in it"), 
but when I expanded it there were actually 4 or 5 unread mails, and when I 
collapsed it, it got green-colored (ie "unread mails in the thread")! So 
it seems that we don't update correctly the unread color in the index.

Subsidiary question : threads are often cut, and i found that certain 
mails sent lack a "references" header, so that I think threading code is 
unable to put it correctly in the thread where it should be. But why these 
messages lack the references header? Is that a bad MUA behaviour?
Bye
Manu