How to Reproduce

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

''(please provide additional details here)''

Request parameters:

{'__FORM_TOKEN': u'3207775f7f00ae6b1b2b5d33',
 'recaptcha_challenge_field': u'03AHJ_Vuvf67IhX11ei_FejIh3khu9lXHZgp_vqN92uKgIg1dVs2l1uJsZRshCGHO0nDZsKoc5PPECvWHNnGgC5U9Ldpq8b16UxuG5TGbS-yjG9_lpFXZ8sGbEP3DP9S06R7xSh5mDrry3Ciq5fWo_idovADXU7GX6wA',
 'recaptcha_response_field': u'undiss lim{Ga'}

User agent: Opera/9.80 (Windows NT 6.1; U; tr) Presto/2.8.131 Version/11.10

System Information

''System information not available''

Enabled Plugins

''Plugin information not available''

Python Traceback

Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/Trac-0.12.1-py2.6.egg/trac/web/main.py", line 511, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/local/lib/python2.6/dist-packages/Trac-0.12.1-py2.6.egg/trac/web/main.py", line 202, in dispatch
    chosen_handler)
  File "/usr/local/lib/python2.6/dist-packages/Trac-0.12.1-py2.6.egg/trac/web/main.py", line 344, in _pre_process_request
    chosen_handler = filter_.pre_process_request(req, chosen_handler)
  File "/usr/local/lib/python2.6/dist-packages/TracSpamFilter-0.4.1dev_r10170-py2.6.egg/tracspamfilter/captcha/api.py", line 119, in pre_process_request
    del req.session['captcha_redirect']
KeyError: 'captcha_redirect'