AttributeError: 'MailingList' object has no attribute 'bounce_processing'

[Vincent Fretin]

With mailman 3.0.0a8

Oct 17 12:06:34 2011 (15436) Traceback (most recent call last):
  File "/home/zope/mailman/src/mailman/core/runner.py", line 138, in _one_iteration
    self._process_one_file(msg, msgdata)
  File "/home/zope/mailman/src/mailman/core/runner.py", line 220, in _process_one_file
    keepqueued = self._dispose(mlist, msg, msgdata)
  File "/home/zope/mailman/src/mailman/runners/bounce.py", line 46, in _dispose
    if not mlist.bounce_processing:
AttributeError: 'MailingList' object has no attribute 'bounce_processing'

It seems that bounce_processing is defined in src/mailman/styles/default.py
The style are applied at mailing-list creation, but bounce_processing attribute is not persisted, the src/mailman/database/mailman.sql file doesn't define it.