Comment 2 for bug 1998226

Reviewed: https://review.opendev.org/c/openstack/neutron/+/866328
Committed: https://opendev.org/openstack/neutron/commit/92efd8e45bef761fc464c932f1fd60d1c4d7e828
Submitter: "Zuul (22348)"
Branch: master

commit 92efd8e45bef761fc464c932f1fd60d1c4d7e828
Author: Fernando Royo <email address hidden>
Date: Thu Dec 1 11:47:58 2022 +0100

    Dont raise RouterInterfaceNotFound on overlap check router ports

    A corner case of the fix done in [1] could happend if, as a race
    scenario, parallel requests evaluate other ports that could be deleted
    during the process if they had already determined a overlapping, in that
    case a RouterInterfaceNotFound exception was raised and the request
    finished with that exception and a 404 status code.

    This patch removes the exception due to a port not found, because if the
    port is not found, the related subnet should not participate in the
    overlap evaluation, so it makes no sense to break the process for a port
    that no longer exists. It also improves the previous validation to
    perform the overlapping check, being performed only when we have
    at least more than one subnet, as the overlapping check with only one
    subnet did not make sense.

    Closes-Bug: #1998226

    [1] https://review.opendev.org/c/openstack/neutron/+/859143

    Change-Id: If4afe6f525c46f9cf7f02d8aae27dfc56144fd62