AttributeError: 'NoneType' object has no attribute 'split'

[aahz@…]

How to Reproduce

While doing a POST operation on /ticket/411, Trac issued an internal error.

(please provide additional details here)

Request parameters:

{'__FORM_TOKEN': u'ebf9ea65f8fe75c21dc66626',
 'action': u'reopen',
 'action_change_owner_reassign_owner': u'anonymous',
 'author': u'aahz@pythoncraft.com',
 'cnum': u'7',
 'comment': u"As a new Trac user, I also find this behavior suboptimal.  It's been five years, please revisit this design flaw -- it makes it very difficult to update a ticket summary so that others don't need to scroll through the entire comment history.",
 'field_component': u'ticket system',
 'field_keywords': u'',
 'field_milestone': u'0.8',
 'field_priority': u'high',
 'field_severity': u'normal',
 'field_summary': u'Edit ticket description?',
 'field_type': u'defect',
 'field_version': u'0.7',
 'id': u'411',
 'preview': u'Preview',
 'replyto': u'',
 'ts': u'2006-06-21 08:26:44+00:00'}

System Information

Trac	0.11.5stable-r8354
Python	2.5.2 (r252:60911, Oct 5 2008, 19:29:17) [GCC 4.3.2]
setuptools	0.6c9
psycopg2	2.0.8
Genshi	0.6dev-r999
Pygments	1.0
Subversion	1.5.1 (r32289)

Python Traceback

Traceback (most recent call last):
  File "/usr/local/virtualenv/lib/python2.5/site-packages/Trac-0.11.5stable_r8354-py2.5.egg/trac/web/main.py", line 444, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/local/virtualenv/lib/python2.5/site-packages/Trac-0.11.5stable_r8354-py2.5.egg/trac/web/main.py", line 205, in dispatch
    resp = chosen_handler.process_request(req)
  File "/usr/local/virtualenv/lib/python2.5/site-packages/Trac-0.11.5stable_r8354-py2.5.egg/trac/ticket/web_ui.py", line 182, in process_request
    return self._process_ticket_request(req)
  File "/usr/local/virtualenv/lib/python2.5/site-packages/Trac-0.11.5stable_r8354-py2.5.egg/trac/ticket/web_ui.py", line 531, in _process_ticket_request
    get_reporter_id(req, 'author'), field_changes)
  File "/usr/local/virtualenv/lib/python2.5/site-packages/Trac-0.11.5stable_r8354-py2.5.egg/trac/ticket/web_ui.py", line 1260, in _insert_ticket_data
    self._render_property_changes(req, ticket, field_changes)
  File "/usr/local/virtualenv/lib/python2.5/site-packages/Trac-0.11.5stable_r8354-py2.5.egg/trac/ticket/web_ui.py", line 1310, in _render_property_changes
    resource_new)
  File "/usr/local/virtualenv/lib/python2.5/site-packages/Trac-0.11.5stable_r8354-py2.5.egg/trac/ticket/web_ui.py", line 1344, in _render_property_diff
    old_list, new_list = old.split(), new.split()
AttributeError: 'NoneType' object has no attribute 'split'

(see source:tags/trac-0.11.5/trac/ticket/web_ui.py@#L1344​)

[Christian Boos]

Thanks for the report.

The keywords field for this ticket must have been NULL in the database, for some reason.

In this case we don't insert this field in the ticket values dict (L103-104), which implies that when setting the field later on, the _old dict ends with a None value (L123-124) in trac/ticket/model.py​.

This was done in r7570 in order to fix #4061, so we can't fix the current issue by inserting '' in values in this case.

I guess we simply need to accept that _old['keywords'] can eventually be None.

trac/ticket/web_ui.py

@@ -1341 +1341 @@
                     'EMAIL_VIEW' in req.perm(resource_new or ticket.resource)):
                 render_elt = obfuscate_email_address
         elif field == 'keywords':
-            old_list, new_list = old.split(), new.split()
+            old_list, new_list = (old or '').split(), new.split()
             sep = ' '
         if (old_list, new_list) != (None, None):
             added = [tag.em(render_elt(x)) for x in new_list

(new can't possibly be None here, but again, I thought the same about old at first inspection ;-) )