dovecot - Oct 2012 - [BUG] Lucene plugin breaks header substring search

According to the IMAP spec if I do a search for "TO isocpp.org" it
should find all the messages whose To: field contains the string
"isocpp.org", but dovecot is returning me an empty list.  However, a
search for "TO tm at isocpp.org" produces a long list of messages. 
This
behavior is present if I *even load* the lucene fts plugin.
Note that lucene isn't in use (fts = squat); it's merely loaded.  This
behavior goes away if I don't load fts_lucene.

Dovecot configuration with dovecot -n:

--8<---------------cut here---------------start------------->8---
# 2.1.6: /usr/local/stow/dovecot-2.1.6/etc/dovecot/dovecot.conf
# OS: Darwin 11.4.2 x86_64  hfs
default_internal_user = _dovecot
default_login_user = _dovenull
mail_gid = 20
mail_location = mdbox:/Users/dave/Library/Data/LocalIMAP/mdbox
mail_plugin_dir = /usr/local/lib/dovecot
mail_plugins = fts fts_squat fts_lucene zlib
mail_uid = 501
maildir_very_dirty_syncs = yes
namespace {
  inbox = yes
  location = 
  prefix = 
  separator = .
  subscriptions = yes
  type = private
}
passdb {
  args = uid=501 gid=20 home=/Users/dave nopassword=y
  driver = static
}
plugin {
  fts = squat
  zlib_save = gz
  zlib_save_level = 6
}
protocols = imap
ssl = no
protocol imap {
  mail_plugins = fts fts_squat fts_lucene zlib
}
--8<---------------cut here---------------end--------------->8---

Dovecot version: 2.1.6

Operating system or Linux distribution name: MacOS X 10.7, 10.8

CPU architecture (x86 or something else?): x86_64

Filesystem you used (especially if you use NFS or not): Mac

Some kind of description of what you were doing and with what IMAP
client.: Searching


-- 
Dave Abrahams
BoostPro Computing                  Software Development        Training
http://www.boostpro.com             Clang/LLVM/EDG Compilers  C++  Boost

On 16.10.2012, at 1.35, Dave Abrahams wrote:
> According to the IMAP spec if I do a search for "TO isocpp.org"
it
> should find all the messages whose To: field contains the string
> "isocpp.org", but dovecot is returning me an empty list. 
However, a
> search for "TO tm at isocpp.org" produces a long list of
messages.
This specific problem can be solved by:

plugin {
  fts_lucene = whitespace_chars=@.
}
> This
> behavior is present if I *even load* the lucene fts plugin.
> Note that lucene isn't in use (fts = squat); it's merely loaded. 
This
> behavior goes away if I don't load fts_lucene.
I don't really see how that's possible. Although a quick test shows me
that fts_squat seems to be completely broken with me for some reason.