Comment 7 for bug 1431201

Reviewed: https://review.openstack.org/164206
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=dddd37d091d89a813fcb97a726c2bf932d6b69ae
Submitter: Jenkins
Branch: master

commit dddd37d091d89a813fcb97a726c2bf932d6b69ae
Author: Dan Smith <email address hidden>
Date: Fri Mar 13 07:51:57 2015 -0700

    Break out the child version calculation logic from obj_make_compatible()

    This pulls out the child version logic from the compatibility routine,
    so that it can be used in other contexts. I left the tests that verify
    the versions pointing at the caller to show that this doesn't break
    anything. Moving them to actually test the core function would be good.

    However, now the inner version calculation logic is a little more
    precise, which changed one of the test cases simply because it was
    not considering the actual child version properly. That same issue
    plagued other cases because we were not properly calling each case on
    a clean copy of the primitive (which didn't matter before).

    Change-Id: Id4071b6bc6e9d4419e9142fa339095f04b182d92
    Related-Bug: #1431201