[Pan-users] Re: Article Threading in Pan 0.101

[Duncan]

Douglas Bollinger <address@hidden> posted
address@hidden, excerpted below, on  Fri, 30 Jun 2006
19:58:57 -0400:

> First off, I would like to thank the Pan developers and especially
> Charles for their renewed interest in this program. 

=8^)

Do note, however, that "renewed" isn't entirely accurate, altho it /did/
appear that way.  During that couple of years PAN development seemed
essentially stalled, Charles was toiling away in secret with the C++
rewrite that became the 0.90+ series.  We are of course all glad he did
it, even if he did keep it secret for all that time.

IOW, it's not "renewed" interest, as Charles was continuing to work on it
during that time.  The rewrite would have been a lot of work, but progress
since 0.90 release seems to indicate that it was worth it, as the new
code seems far easier to update without destabilizing existing working
code, and the weekly updates we are getting now would have been more like
bimonthly updates on the old code.

> Nevertheless, I haven't abandoned text groups entirely.  I've noticed
> that Pan isn't threading articles the best and I'm not sure where the
> fault lies. Here's a link to a screen capture showing the problem:
> 
> http://doug.freeshell.org/files/pan.png
> 
> Anyone else seeing Pan not grouping articles into threads very well or
> it something odd about my USENET server?

Having looked at the screenshot, I can't say it shows anything wrong.  It
would appear that the original thread parent posts aren't shown (no post
to the AMD patent thread without the telltale "Re:" indicating a reply
for all the displayed subthread posts to be children of), likely either
because you have view unread posts toggled off and they aren't displayed,
or because they've either not been downloaded (if you downloaded only X
messages, not everything on the server) or have expired.

With the thread-parent posts not displayed, what remains is a bunch of
different subthreads, some with further posts, some without, which is what
the screenshot shows.  Now, if the references headers of some of those
non-indented posts indicate they should be threaded under the others,
there'd be a problem, but you don't mention references headers, and of
course they aren't shown by default.

What you /might/ be expecting is the behavior certain other clients
display, of threading all posts with the same subject together, regardless
of whether they are related (as given by the references header) or not. 
Sometimes that works.  Sometimes it doesn't.  Consider a test group with a
whole bunch of unrelated posts with the single word "Test" in the subject.
Different people testing different things, totally unrelated to each
other, no references headers indicating they are related because they
aren't, yet clients threading by subject, regardless of references header,
will wrongly display them as part of the same thread!

Do note that as Jim H stated, you can get threading below the parent if it
exists, if you set View, Header Pane, Show Matching Article's Threads. 
That's an option precisely because some people prefer to see the entire
thread, including previously read articles, while others only want to see
unread articles whenever they enter a group.  

It's also possible, as mentioned above, that you only downloaded a certain
arbitrary number of headers, particularly if you just started in the group
or haven't visited it for awhile.  Naturally, in this case, only parts of
certain threads will be available, and it's likely they will form multiple
independent subthreads, because no parent common to both subthreads is
displayed for them to be threaded under.  The cure to this is to use the
download all headers (um... technically overviews, not headers, but I
digress) option, altho that will tend to give you many months worth of
posts on any decent text-group news-server, and ultimately, there will
almost certainly still be some old incomplete threads at the beginning. 
You may also want to check your expire options in this case, as if you
have it set for 30 days and you close pan and restart, it will clean up
all the older posts leaving you with only the 30 days worth you had it
configured for.

Of course, threading by references can't be entirely accurate if someone's
client is screwing up the references headers.  In fact, there were cases
earlier where PAN was infinitely recursing trying to thread headers due to
this very issue -- some client had screwed things up and created an
infinite loop, where parents of some articles appeared as children of
replies.  In such cases, PAN does the best it can, but now detects and
cuts the infinite loop, and may display inaccurate threading as a result
of those inaccurate references headers.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman