mitsuhiko/flask — pull request #417 by tarruda (2012-03-02 10:51:42+00:00)
Title: Fixed assumption made on session implementations

In the snippet 'session.setdefault(...).append(...)', it was being
assumed that changes made to mutable structures in the session are
are always in sync with the session object, which is not true for
session implementations that use a external storage for keeping their
keys/values.