AttributeError exception on repo search

[anonymous]

Getting a Trac 'Oops' page when trying a repo-search:

Traceback (most recent call last):
  File "C:\Python23\Lib\site-packages\trac\web\modpython_frontend.py", line 206, in handler
    dispatch_request(mpr.path_info, mpr, env)
  File "C:\Python23\Lib\site-packages\trac\web\main.py", line 139, in dispatch_request
    dispatcher.dispatch(req)
  File "C:\Python23\Lib\site-packages\trac\web\main.py", line 107, in dispatch
    resp = chosen_handler.process_request(req)
  File "C:\Python23\Lib\site-packages\trac\Search.py", line 158, in process_request
    results += list(source.get_search_results(req, query, filters))
  File "build\bdist.win32\egg\tracreposearch\search.py", line 104, in get_search_results
  File "build\bdist.win32\egg\tracreposearch\search.py", line 85, in full_walker
AttributeError: 'NoneType' object has no attribute 'read'

[Alec Thomas]

(In [676]) * Fixes #320