dmwm/WMCore — pull request #5384 by amaltaro (2014-10-03 10:18:20+00:00)
Title: properly handle None in JobAccountant

Handle None as None instead of 'None', so now it raises the correct exception.

As discussed with @ticoann , we are not sure when it happens, so in principle we cannot
simply drop that file. Developer manual intervention is still needed for this case.
Seangchan, review please. If you know how to automatically recover it, please let me know :-)