error when accepting/closing a ticket

[xris(a)siliconmechanics(o)com]

[1558]

trying to accept or close a ticket, I get "Trac detected an internal error: 0"

backing down to an earlier known-working revision doesn't seem to help.

Traceback (most recent call last):
  File "/usr/lib/python2.2/site-packages/trac/web/cgi_frontend.py", line 103, in run
    dispatch_request(os.getenv('PATH_INFO', ''), req, env)
  File "/usr/lib/python2.2/site-packages/trac/web/main.py", line 302, in dispatch_request
    module.render(req)
  File "/usr/lib/python2.2/site-packages/trac/Ticket.py", line 539, in render
    self.save_changes(req, id)
  File "/usr/lib/python2.2/site-packages/trac/Ticket.py", line 397, in save_changes
    if 'description' in req.args or 'reporter' in req.args:
  File "/usr/lib/python2.2/cgi.py", line 550, in __getitem__
    raise KeyError, key
KeyError: 0

[Mark Rowe]

Duplicate of #1475.