Comment 12 for bug 1785339

Reviewed: https://review.openstack.org/605879
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=556079a33997958d26fb7f03946998a6b06f488c
Submitter: Zuul
Branch: stable/pike

commit 556079a33997958d26fb7f03946998a6b06f488c
Author: Matt Riedemann <email address hidden>
Date: Fri Aug 3 19:11:37 2018 -0400

    Update RequestSpec.flavor on resize_revert

    Since I8abdf58a6537dd5e15a012ea37a7b48abd726579 in Newton
    we update the RequestSpec.flavor to the new flavor during
    a resize. However, if the resize is reverted, we didn't
    revert the RequestSpec.flavor to the previous flavor
    on the instance, which could cause issues later when
    moving the instance since the scheduler will get a
    RequestSpec with a flavor that doesn't match the actual
    flavor on the instance.

    This fixes the bug by updating the RequestSpec.flavor
    with instance.old_flavor on resize_revert in the API.
    Functional test wrinkles are added.

    This fix was ported from the starlingx-staging/stx-nova
    repo commit 71acfeae0.

    Conflicts:
          nova/tests/functional/test_servers.py

    NOTE(mriedem): The conflict is due to not having change
    I40a244601e1612a87bd41cd6ad652202035a1ce4 in Pike, which
    would be difficult to backport because of change
    I89e2682c9210901cf1992dac2f9068b51f0373cd not being in
    Pike, so it's easier to just update the existing tests
    as they were in Pike.

    Change-Id: Ic6e74702f2a5b57b437f4ffdfbc86c1e34cdac7d
    Closes-Bug: #1785339
    (cherry picked from commit ef3849e2da1c94df519debcb14ba15af9bd01a60)
    (cherry picked from commit 9125fc7caf68fcecea47a3f0ac5068cf44a97821)
    (cherry picked from commit f2d2a9a7c538f87775092c6cbf3b03b463cbdc2a)