Router interface add port without subnet raise indexerror

[Tristan Cacqueray]

Trace:
ERROR neutron.api.v2.resource [req-dbf179d1-62ac-4537-be15-c2088669f75c ] add_router_interface failed
TRACE neutron.api.v2.resource Traceback (most recent call last):
TRACE neutron.api.v2.resource File "/usr/lib/python2.7/site-packages/neutron/api/v2/resource.py", line 83, in resource
TRACE neutron.api.v2.resource result = method(request=request, **args)
TRACE neutron.api.v2.resource File "/usr/lib/python2.7/site-packages/neutron/api/v2/base.py", line 207, in _handle_action
TRACE neutron.api.v2.resource return getattr(self._plugin, name)(*arg_list, **kwargs)
TRACE neutron.api.v2.resource File "/usr/lib/python2.7/site-packages/neutron/db/l3_dvr_db.py", line 306, in add_router_interface
TRACE neutron.api.v2.resource router_id, port['tenant_id'], port['id'], subnets[-1]['id'],
TRACE neutron.api.v2.resource IndexError: list index out of range

Steps to reproduce:
router_id=$(neutron router-create test | grep ' id ' | awk '{ print $4 }')
neutron net-create test
port_id=$(neutron port-create test | grep ' id ' | awk '{ print $4 }')
neutron router-interface-add $router_id port=$port_id

Impact:
Raise an IndexError exception instead of NeutronError

[Sridhar Gaddam (sridhargaddam)]

The issue is fixed as part of the following patch - https://review.openstack.org/#/c/193440/