Comment 4 for bug 1489618

Reviewed: https://review.openstack.org/493070
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=58b14a83bce12cceeeabcc3531f4b2c842591b5f
Submitter: Zuul
Branch: master

commit 58b14a83bce12cceeeabcc3531f4b2c842591b5f
Author: Bence Romsics <email address hidden>
Date: Mon Aug 14 15:30:51 2017 +0200

    transfer-table: Rethink CHANGED message handler

    Part of the fix to bug #1489618 was working only accidentally. The
    implicit update logic of the allocated table (and the allocatedIds dict)
    treated ctrl.available.sourceItems and ctrl.allocated.sourceItems as
    parallel arrays, while they were not parallel in fact.

    This change allows the sender of the CHANGED message to specify all four
    tables and by that spare any implicit logic of updating some of the
    tables. However if a table is not included in the CHANGED message it
    will be left unchanged. The event is also renamed according to the new
    meaning.

    The single sender of the original message from the horizon repo (ie.
    Launch Instance / Source) is updated.

    The original message type and its handler logic is removed without
    deprecation. That theoretically could cause problems for horizon plugins
    outside of the horizon repo. But I find that unlikely because if
    somebody had relied on that logic they would have likely discovered
    already that it was faulty.

    Change-Id: I38972558e1823f9a88702d2ebcb8de5244cfe16a
    Related-Change: I647b31c7a280af4e10040fb27b4436d489fd8163
    Related-Bug: #1489618