Comment 5 for bug 1292495

Reviewed: https://review.openstack.org/80569
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=61b804a861d27bb10bc14c778ad7d489ed42f24d
Submitter: Jenkins
Branch: master

commit 61b804a861d27bb10bc14c778ad7d489ed42f24d
Author: Sergey Kraynev <email address hidden>
Date: Fri Mar 14 09:33:12 2014 -0400

    Using resolving properties for update

    For definition reference in template we should use built-in functions.
    So template after parsing with resolve_static_data will contain
    references on these functions instead resolve values.
    If we want get some information about previous state of stack during
    update, we should use self.properties instead of self.t['Properties'].
    Also default=[] was added to avoid error when we try to do set([]).

    Closes-bug: #1292495
    Change-Id: I0cc44a0a541913cca665caec1a7f3a2a1a6cebc9