Comment 12 for bug 1300972

Reviewed: https://review.openstack.org/111803
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=825cfe4ab2696612a832e6a90e7ae69816fb7e28
Submitter: Jenkins
Branch: stable/icehouse

commit 825cfe4ab2696612a832e6a90e7ae69816fb7e28
Author: Christopher Yeoh <email address hidden>
Date: Tue Apr 8 16:08:56 2014 +0930

    Fix _parse_datetime in simple tenant usage extension

    _parse_datetime in os-simple-tenant-usage incorrectly attempts
    to parse the datetime string even when it is None. As a result
    a 400 BadRequest is returned. This has the overall effect of making
    the start and end datetime parameters compulsory when they are meant
    to be optional.

    Note that this restores the behavior where start/end are optional which is
    in contradiction to the API docs, but is the long standing API behaviour.
    This was an API change which was accidentally applied in commit
    I8e0e870727d687da165c809ffb7a4456bff81122 as part of some nova internal
    changes but not picked up by the unitests

    Change-Id: I00427379dc7aa39770f9a16ff026addb6e311735
    Closes-Bug: 1300972
    (cherry picked from commit 99e6ec9131c2e3eeb5fe3e1a4dc5a26e6302ebd2)