Running update.php after installing AbuseFilter on trunk I get:

Creating abuse_filter table ...done.
...abuse_filter_history table already exists.
...have afh_changed_fields field in abuse_filter_history table.
...have af_deleted field in abuse_filter table.
...have af_actions field in abuse_filter table.
...have af_global field in abuse_filter table.
...have afl_rev_id field in abuse_filter_log table.
...index filter_timestamp already set on abuse_filter_log table.
...have af_group field in abuse_filter table.
...index wiki_timestamp already set on abuse_filter_log table.

Notice: SiteStatsUpdate::doUpdate: Transaction already in progress (from DatabaseUpdater::doUpdates), performing implicit commit! [Called from D
core\includes\db\Database.php at line 2944] in D:\F_Programmierung\xampp\htdocs\core\includes\debug\Debug.php on line 283
...site_stats is populated...done.
Purging caches...done.

Notice: DatabaseUpdater::doUpdates: No transaction to commit, something got out of sync! [Called from DatabaseBase::commit in D:\F_Programmierung
1] in D:\F_Programmierung\xampp\htdocs\core\includes\debug\Debug.php on line 283
...rev_len column of revision table already populated.
....

Version: 1.21.x
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=41170