[Open Crypto Project] #56: Trac Internal Error: AttributeError: 'NoneType' object has no attribute 'split'

[Open Crypto Project]

#56: Trac Internal Error:  AttributeError: 'NoneType' object has no attribute
'split'
-----------------------+-----------------
  Reporter:  pselkirk  |      Owner:
      Type:  defect    |     Status:  new
  Priority:  minor     |  Milestone:
 Component:  wiki      |    Version:
Resolution:            |   Keywords:
Blocked By:            |   Blocking:
-----------------------+-----------------

Comment (by sra):

 Managed to catch an example of this, with a backtrace:
 {{{
 Traceback (most recent call last):
   File "/usr/local/lib/python2.7/site-packages/trac/web/main.py", line
 554, in _dispatch_request
     dispatcher.dispatch(req)
   File "/usr/local/lib/python2.7/site-packages/trac/web/main.py", line
 247, in dispatch
     resp = chosen_handler.process_request(req)
   File "/usr/local/lib/python2.7/site-packages/trac/ticket/web_ui.py",
 line 182, in process_request
     return self._process_ticket_request(req)
   File "/usr/local/lib/python2.7/site-packages/trac/ticket/web_ui.py",
 line 625, in _process_ticket_request
     self._do_save(req, ticket, action)
   File "/usr/local/lib/python2.7/site-packages/trac/ticket/web_ui.py",
 line 1357, in _do_save
     replyto=req.args.get('replyto'))
   File "/usr/local/lib/python2.7/site-packages/trac/ticket/model.py", line
 369, in save_changes
     listener.ticket_changed(self, comment, author, old_values)
   File "/usr/local/lib/python2.7/site-packages/mastertickets/api.py", line
 111, in ticket_changed
     links.save(author, comment, tkt.time_changed, db)
   File "/usr/local/lib/python2.7/site-packages/mastertickets/model.py",
 line 67, in save
     new_value = [x.strip() for x in old_value.split(',') if x.strip()]
 AttributeError: 'NoneType' object has no attribute 'split'
 }}}

 So patched:
 {{{
 #!diff
 Index: mastertickets/model.py
 --- mastertickets/model.py~     2011-10-19 17:47:42.000000000 +0000
 +++ mastertickets/model.py      2016-05-06 22:34:18.000000000 +0000
 @@ -63,7 +63,7 @@
                  if update_field is not None:
                      cursor.execute('SELECT value FROM ticket_custom WHERE
 ticket=%s AND name=%s',
                                     (n, str(field)))
 -                    old_value = (cursor.fetchone() or ('',))[0]
 +                    old_value = (cursor.fetchone() or ('',))[0] or ''
                      new_value = [x.strip() for x in old_value.split(',')
 if x.strip()]
                      update_field(new_value)
                      new_value = ', '.join(sorted(new_value, key=lambda x:
 int(x)))
 }}}

 In English, for those who have not had the misfortune to have memorized
 the Python DB2 SQL API, that's "If the SQL column was NULL, give me an
 empty string instead of None."

 We'll see.

--
Ticket URL: <https://trac.cryptech.is/ticket/56#comment:2>
Open Crypto Project <https://wiki.cryptech.is/>