From mboxrd@z Thu Jan  1 00:00:00 1970
From: rlane@club.cc.cmu.edu (Rich Lane)
Date: Thu, 10 Sep 2009 12:16:35 -0400
Subject: [sup-talk] U (unread) search is off
In-Reply-To: <1252590993-sup-3885@masanjin.net>
References: <1252504368-sup-9406@ntdws12.chass.utoronto.ca>
	<1252581713-sup-9701@cannonball> <1252590993-sup-3885@masanjin.net>
Message-ID: <1252595946-sup-171@zyrg.net>

There are actually 2 bugs in this thread. Ben is still using Xapian
1.0.14 which doesn't have my fix for the phantom labels problem.
Ingmar's message was about the surprise Xapian::QueryParser feature.

Excerpts from William Morgan's message of Thu Sep 10 09:59:13 -0400 2009:
> Reformatted excerpts from Ingmar Vanhassel's message of 2009-09-10:
> > Known issue, see http://mid.gmane.org/1251792282-sup-2057 at cannonball and
> > Rich's answer to my mail.
> 
> Actually, I haven't been following this too closely, but what is the status?
> I noticed we have this in xapian_index.rb:
>     qp.default_op = Xapian::Query::OP_AND
> 
> Is that not sufficient (combined with a newish Xapian, I guess?) to fix
> the problem?

I thought it was, but it turns out that unless you explicitly add AND
operators Xapian will OR terms over the same field such that
"label:foo label:bar" gives you the union instead of the intersection.

We could fix this by patching Xapian to make this behavior configurable,
or we could come up with an index-agnostic simple query language that
doesn't support boolean operators. The native query language would still
be available, of course, but the simple one would suffice for most usage
and potentially have Sup-specific features.