451842 - filter rules changing from AND to OR, causing many false matches

Status: RESOLVED WORKSFORME

(MailNews Core :: Filters, defect)

Description

[Nelson Bolyard (seldom reads bugmail)]

SM trunk Gecko/20080816002821 

Something is causing some of my news filter rules to change from AND to OR.
It seems to only affect rules whose action includes "ignore thread".
It has the effect that those rules start to cause all threads to be read.
It happened to numerous rules for various newsgroups, sometime in the past
week.  These are rules I've had for months, working fine, then suddenly 
changed with the effect that they ignore all threads.

This explains a great deal of the phenomena I've seen in the past.
This is a cause of the behavior I've seen (and reported) before, where 
I find that, every day when I go to read certain newsgroup, it tells me 
there are no new messages, the view-threads-with-unread display shows NO 
threads, and the view all threads shows only a very few threads.  

In some newsgroups, I have numerous filters of this form:
   Match ALL of the following:
     From contains <email address>
     Subject doesn't contain Re:
   Perform action
     Ignore thread
     mark as read
     stop filter execution

This is intended to kill threads that are initiated by certain individuals,
but not threads in which those individuals participate as commenters.  

Somehow, many of those rules magically changed from 
    Match ALL of the following
to 
    Match ANY of the following 

This had the effect that it was ignoring all new threads.  Only old threads 
that predated the time of this change continue to appear.  

Unfortunately, it seems that removing the affected .msf files is the only
way to eliminate all the bogus records of wrongly-ignored threads.  :(
I find it necessary to fix the bad filter rules, then remove the .msf file, 
then change the .rc file to go back and re-read the past few hundred messages.

Comment 1

[Nelson Bolyard (seldom reads bugmail)]

I wrote:
> It has the effect that those rules start to cause all threads to be read.
I meant:
> It has the effect that those rules start to cause all threads to be IGNORED.

Comment 2

[Mark Banner (:standard8)]

Is this is a one-off change, or one that happens every now and again? If its only happened once (or you've only noticed it once so far) that's ok, it might just help to find the problem.

I haven't got time to check now, but I wonder if someone could go back to the last release, set up some filters and come to latest trunk and play around to see if they change or not.

Comment 3

[Nelson Bolyard (seldom reads bugmail)]

It is not happening frequently.  It may have happened only once.
I'll let you know if it happens again.

It happened to two filter rules in two newsgroups, but it did not happen
to all similar rules in all newsgroups.  

Comment 4

[David :Bienvenu]

if we ever get evidence that this has happened more than once, then we can re-evaluate the blocking status. FWIW, I've never seen it happen.

Comment 5

[Wayne Mery (:wsmwk)]

It would be useful to know if this still occurs on current trunk.  I'm  thinking this is WFM, unless there is an underlying problem with msf files

Comment 6

[Nelson Bolyard (seldom reads bugmail)]

This happened to me once, a year ago.  Haven't had a recurrence since then.
I'm willing to forget about it.