diff --git a/hgext/bugzilla.py b/hgext/bugzilla.py
new file mode 100644
--- /dev/null
+++ b/hgext/bugzilla.py
@@ -0,0 +1,293 @@
+# bugzilla.py - bugzilla integration for mercurial
+#
+# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
+#
+# This software may be used and distributed according to the terms
+# of the GNU General Public License, incorporated herein by reference.
+#
+# hook extension to update comments of bugzilla bugs when changesets
+# that refer to bugs by id are seen.  this hook does not change bug
+# status, only comments.
+#
+# to configure, add items to '[bugzilla]' section of hgrc.
+#
+# to use, configure bugzilla extension and enable like this:
+#
+#   [extensions]
+#   hgext.bugzilla =
+#
+#   [hooks]
+#   # run bugzilla hook on every change pulled or pushed in here
+#   incoming.bugzilla = python:hgext.bugzilla.hook
+#
+# config items:
+#
+# REQUIRED:
+#   host = bugzilla # mysql server where bugzilla database lives
+#   password = **   # user's password
+#   version = 2.16  # version of bugzilla installed
+#
+# OPTIONAL:
+#   bzuser = ...    # bugzilla user id to record comments with
+#   db = bugs       # database to connect to
+#   hgweb = http:// # root of hg web site for browsing commits
+#   notify = ...    # command to run to get bugzilla to send mail
+#   regexp = ...    # regexp to match bug ids (must contain one "()" group)
+#   strip = 0       # number of slashes to strip for url paths
+#   style = ...     # style file to use when formatting comments
+#   template = ...  # template to use when formatting comments
+#   timeout = 5     # database connection timeout (seconds)
+#   user = bugs     # user to connect to database as
+
+from mercurial.demandload import *
+from mercurial.i18n import gettext as _
+from mercurial.node import *
+demandload(globals(), 'cStringIO mercurial:templater,util os re time')
+
+try:
+    import MySQLdb
+except ImportError:
+    raise util.Abort(_('python mysql support not available'))
+
+def buglist(ids):
+    return '(' + ','.join(map(str, ids)) + ')'
+
+class bugzilla_2_16(object):
+    '''support for bugzilla version 2.16.'''
+
+    def __init__(self, ui):
+        self.ui = ui
+        host = self.ui.config('bugzilla', 'host', 'localhost')
+        user = self.ui.config('bugzilla', 'user', 'bugs')
+        passwd = self.ui.config('bugzilla', 'password')
+        db = self.ui.config('bugzilla', 'db', 'bugs')
+        timeout = int(self.ui.config('bugzilla', 'timeout', 5))
+        self.ui.note(_('connecting to %s:%s as %s, password %s\n') %
+                     (host, db, user, '*' * len(passwd)))
+        self.conn = MySQLdb.connect(host=host, user=user, passwd=passwd,
+                                    db=db, connect_timeout=timeout)
+        self.cursor = self.conn.cursor()
+        self.run('select fieldid from fielddefs where name = "longdesc"')
+        ids = self.cursor.fetchall()
+        if len(ids) != 1:
+            raise util.Abort(_('unknown database schema'))
+        self.longdesc_id = ids[0][0]
+        self.user_ids = {}
+
+    def run(self, *args, **kwargs):
+        '''run a query.'''
+        self.ui.note(_('query: %s %s\n') % (args, kwargs))
+        try:
+            self.cursor.execute(*args, **kwargs)
+        except MySQLdb.MySQLError, err:
+            self.ui.note(_('failed query: %s %s\n') % (args, kwargs))
+            raise
+
+    def filter_real_bug_ids(self, ids):
+        '''filter not-existing bug ids from list.'''
+        self.run('select bug_id from bugs where bug_id in %s' % buglist(ids))
+        ids = [c[0] for c in self.cursor.fetchall()]
+        ids.sort()
+        return ids
+
+    def filter_unknown_bug_ids(self, node, ids):
+        '''filter bug ids from list that already refer to this changeset.'''
+
+        self.run('''select bug_id from longdescs where
+                    bug_id in %s and thetext like "%%%s%%"''' %
+                 (buglist(ids), short(node)))
+        unknown = dict.fromkeys(ids)
+        for (id,) in self.cursor.fetchall():
+            self.ui.status(_('bug %d already knows about changeset %s\n') %
+                           (id, short(node)))
+            unknown.pop(id, None)
+        ids = unknown.keys()
+        ids.sort()
+        return ids
+
+    def notify(self, ids):
+        '''tell bugzilla to send mail.'''
+
+        self.ui.status(_('telling bugzilla to send mail:\n'))
+        for id in ids:
+            self.ui.status(_('  bug %s\n') % id)
+            cmd = self.ui.config('bugzilla', 'notify',
+                               'cd /var/www/html/bugzilla && '
+                               './processmail %s nobody@nowhere.com') % id
+            fp = os.popen('(%s) 2>&1' % cmd)
+            out = fp.read()
+            ret = fp.close()
+            if ret:
+                self.ui.warn(out)
+                raise util.Abort(_('bugzilla notify command %s') %
+                                 util.explain_exit(ret)[0])
+        self.ui.status(_('done\n'))
+
+    def get_user_id(self, user):
+        '''look up numeric bugzilla user id.'''
+        try:
+            return self.user_ids[user]
+        except KeyError:
+            try:
+                userid = int(user)
+            except ValueError:
+                self.ui.note(_('looking up user %s\n') % user)
+                self.run('''select userid from profiles
+                            where login_name like %s''', user)
+                all = self.cursor.fetchall()
+                if len(all) != 1:
+                    raise KeyError(user)
+                userid = int(all[0][0])
+            self.user_ids[user] = userid
+            return userid
+
+    def add_comment(self, bugid, text, prefuser):
+        '''add comment to bug. try adding comment as committer of
+        changeset, otherwise as default bugzilla user.'''
+        try:
+            userid = self.get_user_id(prefuser)
+        except KeyError:
+            try:
+                defaultuser = self.ui.config('bugzilla', 'bzuser')
+                userid = self.get_user_id(defaultuser)
+            except KeyError:
+                raise util.Abort(_('cannot find user id for %s or %s') %
+                                 (prefuser, defaultuser))
+        now = time.strftime('%Y-%m-%d %H:%M:%S')
+        self.run('''insert into longdescs
+                    (bug_id, who, bug_when, thetext)
+                    values (%s, %s, %s, %s)''',
+                 (bugid, userid, now, text))
+        self.run('''insert into bugs_activity (bug_id, who, bug_when, fieldid)
+                    values (%s, %s, %s, %s)''',
+                 (bugid, userid, now, self.longdesc_id))
+
+class bugzilla(object):
+    # supported versions of bugzilla. different versions have
+    # different schemas.
+    _versions = {
+        '2.16': bugzilla_2_16,
+        }
+
+    _default_bug_re = (r'bugs?\s*,?\s*(?:#|nos?\.?|num(?:ber)?s?)?\s*'
+                       r'((?:\d+\s*(?:,?\s*(?:and)?)?\s*)+)')
+
+    _bz = None
+
+    def __init__(self, ui, repo):
+        self.ui = ui
+        self.repo = repo
+
+    def bz(self):
+        '''return object that knows how to talk to bugzilla version in
+        use.'''
+
+        if bugzilla._bz is None:
+            bzversion = self.ui.config('bugzilla', 'version')
+            try:
+                bzclass = bugzilla._versions[bzversion]
+            except KeyError:
+                raise util.Abort(_('bugzilla version %s not supported') %
+                                 bzversion)
+            bugzilla._bz = bzclass(self.ui)
+        return bugzilla._bz
+
+    def __getattr__(self, key):
+        return getattr(self.bz(), key)
+
+    _bug_re = None
+    _split_re = None
+
+    def find_bug_ids(self, node, desc):
+        '''find valid bug ids that are referred to in changeset
+        comments and that do not already have references to this
+        changeset.'''
+
+        if bugzilla._bug_re is None:
+            bugzilla._bug_re = re.compile(
+                self.ui.config('bugzilla', 'regexp', bugzilla._default_bug_re),
+                re.IGNORECASE)
+            bugzilla._split_re = re.compile(r'\D+')
+        start = 0
+        ids = {}
+        while True:
+            m = bugzilla._bug_re.search(desc, start)
+            if not m:
+                break
+            start = m.end()
+            for id in bugzilla._split_re.split(m.group(1)):
+                ids[int(id)] = 1
+        ids = ids.keys()
+        if ids:
+            ids = self.filter_real_bug_ids(ids)
+        if ids:
+            ids = self.filter_unknown_bug_ids(node, ids)
+        return ids
+
+    def update(self, bugid, node, changes):
+        '''update bugzilla bug with reference to changeset.'''
+
+        def webroot(root):
+            '''strip leading prefix of repo root and turn into
+            url-safe path.'''
+            count = int(self.ui.config('bugzilla', 'strip', 0))
+            root = util.pconvert(root)
+            while count > 0:
+                c = root.find('/')
+                if c == -1:
+                    break
+                root = root[c+1:]
+                count -= 1
+            return root
+
+        class stringio(object):
+            '''wrap cStringIO.'''
+            def __init__(self):
+                self.fp = cStringIO.StringIO()
+
+            def write(self, *args):
+                for a in args:
+                    self.fp.write(a)
+
+            write_header = write
+
+            def getvalue(self):
+                return self.fp.getvalue()
+
+        mapfile = self.ui.config('bugzilla', 'style')
+        tmpl = self.ui.config('bugzilla', 'template')
+        sio = stringio()
+        t = templater.changeset_templater(self.ui, self.repo, mapfile, sio)
+        if not mapfile and not tmpl:
+            tmpl = _('changeset {node|short} in repo {root} refers '
+                     'to bug {bug}.\ndetails:\n\t{desc|tabindent}')
+        if tmpl:
+            tmpl = templater.parsestring(tmpl, quoted=False)
+            t.use_template(tmpl)
+        t.show(changenode=node, changes=changes,
+               bug=str(bugid),
+               hgweb=self.ui.config('bugzilla', 'hgweb'),
+               root=self.repo.root,
+               webroot=webroot(self.repo.root))
+        self.add_comment(bugid, sio.getvalue(), templater.email(changes[1]))
+
+def hook(ui, repo, hooktype, node=None, **kwargs):
+    '''add comment to bugzilla for each changeset that refers to a
+    bugzilla bug id. only add a comment once per bug, so same change
+    seen multiple times does not fill bug with duplicate data.'''
+    if node is None:
+        raise util.Abort(_('hook type %s does not pass a changeset id') %
+                         hooktype)
+    try:
+        bz = bugzilla(ui, repo)
+        bin_node = bin(node)
+        changes = repo.changelog.read(bin_node)
+        ids = bz.find_bug_ids(bin_node, changes[4])
+        if ids:
+            for id in ids:
+                bz.update(id, bin_node, changes)
+            bz.notify(ids)
+        return True
+    except MySQLdb.MySQLError, err:
+        raise util.Abort(_('database error: %s') % err[1])
+