edx/edx-platform — pull request #4295 by carsongee (2014-07-02 21:53:23+00:00)
Title: Check if user is anonymous before calling PSYCHOMETRICS

LTI grade callbacks for example, come in with an anonymous user. This causes a
stack trace in the psychometrics app that leads to the LTI service
getting a 404 when trying to grade. This adds a check before that callback gets registered.