trac return 500 error when the request has no Accept-Language header

[anonymous]

While using curl/wget to GET /ticket/xxxx, Trac return 500 error like below.This issue can be fixed by adding an "Accept-Language" header to the command.

ticketext version: r10092

command: curl ​http://myhost/ticket/xxxx

Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/trac/web/main.py", line 511, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.6/site-packages/trac/web/main.py", line 248, in dispatch
    self._post_process_request(req, *resp)
  File "/usr/lib/python2.6/site-packages/trac/web/main.py", line 357, in _post_process_request
    resp = f.post_process_request(req, *resp)
  File "/usr/lib/python2.6/site-packages/ticketext/template.py", line 42, in post_process_request
    locale = LocaleUtil().get_locale(req)
  File "/usr/lib/python2.6/site-packages/ticketext/api.py", line 22, in get_locale
    if (len(locale_array) > 0):
TypeError: object of type 'NoneType' has no len()