Viewing revision might cause oops

  KeyError: u'\xe2'

    Traceback (most recent call last):
  Module oops_wsgi.middleware, line 210, in oops_middleware
    app(environ, oops_start_response))
  Module paste.deploy.config, line 291, in __call__
    return self.app(environ, start_response)
  Module launchpad_loggerhead.wsgi, line 90, in wrapped
    app, environ, start_response, request_done_err, request_done_ok)
  Module paste.wsgilib, line 185, in catch_errors
    app_iter = application(environ, start_response)
  Module launchpad_loggerhead.wsgi, line 67, in wrapped
    return app(environ, response_hook)
  Module launchpad_loggerhead.revision, line 34, in __call__
    return self.application(environ, response_hook)
  Module launchpad_loggerhead.session, line 85, in __call__
    return self.application(environ, response_hook)
  Module paste.httpexceptions, line 640, in __call__
    return self.application(environ, start_response)
  Module launchpad_loggerhead.app, line 288, in __call__
    return view.app(environ, start_response)
  Module loggerhead.apps.branch, line 207, in app
    return c(environ, start_response)
  Module loggerhead.controllers, line 129, in __call__
    self.add_template_values(values)
  Module loggerhead.controllers.revision_ui, line 142, in add_template_values
    dq(item.filename))
  Module loggerhead.controllers.revision_ui, line 35, in dq
    return urlutils.quote(urlutils.quote(p, safe=''))
  Module breezy.urlutils, line 156, in quote_from_bytes
    return ''.join(map(quoter, s))
KeyError: u'\xe2'