TypeError: argument of type 'NoneType' is not iterable

[pmoors]

How to Reproduce

While doing a POST operation on /ticket/1, Trac issued an internal error.

(please provide additional details here)

Request parameters:

{'__FORM_TOKEN': u'06df69c64ea433f46baa4d05',
 'action': u'leave',
 'cnum': u'3',
 'comment': u'comment',
 'field_blockedby': u'',
 'field_blocking': u'2',
 'field_cc': u'',
 'field_class': u'',
 'field_decisionlevel': u'owner',
 'field_description': u'Update wordprocessor featurelist',
 'field_estimatedhours': u'0',
 'field_keywords': u'',
 'field_milestone': u'',
 'field_priority': u'major',
 'field_reporter': u'pmoors',
 'field_severity': u'Safety/security',
 'field_summary': u'Demo ticket',
 'field_tcf_module': u'',
 'field_tcf_submodule': u'',
 'field_team': u'AMT',
 'field_type': u'defect',
 'field_version': u'',
 'id': u'1',
 'replyto': u'',
 'submit': u'Submit changes',
 'ts': u'2009-12-03 13:26:17+00:00'}

User Agent was: Mozilla/5.0 (Windows; U; Windows NT 5.1; nl; rv:1.9.1.5) Gecko/20091102 Firefox/3.5.5 GTB6 (.NET CLR 3.5.30729)

System Information

Trac	0.11.6
Python	2.5.2 (r252:60911, Jul 22 2009, 15:52:25) [GCC 4.2.4 (Ubuntu 4.2.4-1ubuntu3)]
setuptools	0.6c11
psycopg2	2.0.6
Genshi	0.5.1
mod_python	3.3.1
Subversion	1.4.6 (r28521)
CustomFieldAdmin	0.2.2
jQuery:	1.2.6

Python Traceback

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/Trac-0.11.6-py2.5.egg/trac/web/main.py", line 450, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.5/site-packages/Trac-0.11.6-py2.5.egg/trac/web/main.py", line 206, in dispatch
    resp = chosen_handler.process_request(req)
  File "/usr/lib/python2.5/site-packages/Trac-0.11.6-py2.5.egg/trac/ticket/web_ui.py", line 182, in process_request
    return self._process_ticket_request(req)
  File "/usr/lib/python2.5/site-packages/Trac-0.11.6-py2.5.egg/trac/ticket/web_ui.py", line 504, in _process_ticket_request
    valid = self._validate_ticket(req, ticket) and not problems
  File "/usr/lib/python2.5/site-packages/Trac-0.11.6-py2.5.egg/trac/ticket/web_ui.py", line 977, in _validate_ticket
    for field, message in manipulator.validate_ticket(req, ticket):
  File "/usr/lib/python2.5/site-packages/TracHoursPlugin-0.5.2-py2.5.egg/trachours/ticket.py", line 45, in validate_ticket
    can_add_hours = PermissionSystem(self.env).check_permission('TICKET_ADD_HOURS', user)
  File "/usr/lib/python2.5/site-packages/Trac-0.11.6-py2.5.egg/trac/perm.py", line 428, in check_permission
    perm)
  File "build/bdist.linux-i686/egg/privatetickets/policy.py", line 34, in check_permission
    'TRAC_ADMIN' in perm:
TypeError: argument of type 'NoneType' is not iterable

[Remy Blank]

PluginIssue (PrivateTicketsPlugin).