Comment 10 for bug 1682693

Reviewed: https://review.openstack.org/457335
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=c9620d57c84378c6187485d571e60e9da3eb9737
Submitter: Jenkins
Branch: stable/ocata

commit c9620d57c84378c6187485d571e60e9da3eb9737
Author: Matt Riedemann <email address hidden>
Date: Sun Apr 16 20:45:25 2017 -0400

    Add regression test for server filtering by tags bug 1682693

    There was a latent bug in the DB API code such that when we
    process filters when listing instances, the various tags
    filters have their values popped out of the filters dict and
    the values (which are lists) for the filter also have the
    first item in the list popped out to build the query.

    This latent bug was exposed in Newton when we started listing
    instances in the API from both cell0 and the main cell database,
    because the query to cell0 would pop an item and then it
    would not be in the 2nd query to the main cell database. If we
    only had one tag in the filter list, we get an IndexError on
    the 2nd pop() call.

    Note that we also use the build_requests table in the API to
    list instances, but there would not be any tagged servers in
    that table since a server has to be ACTIVE before you can tag it,
    and build_requests only exist until the instance is put into a
    cell and starts building there (so it won't be ACTIVE yet).

    Change-Id: I65bdfadd406368775c794ee4d8a16302a8a134bc
    Related-Bug: #1682693
    (cherry picked from commit 01dd1a05a213c0cbd0097188418cabe915291c8d)