Neutron fixture: don't clobber profile and vif_details if empty

Previously, the way Neutron fixture's update_port method was coded
would cause the binding:profile and binding:vid_details fields to get
clobbered if they were not passed to the update. This was because if
nothing was passed, a default of {} was used. This is not how the real
Neutron API behaves. If nothing is passed, the previous values remain
and are not replaced with {}. This patches fixes this in the Neutron
fixture.

Change-Id: Ia7ad1322b5a15d1407140c77fe0edb179f66ec7a
(cherry picked from commit 62868aa)

Author: notartom

nova/tests/fixtures.py

@@ -2034,16 +2034,19 @@ def update_port(self, port_id, body=None):
                 # else update the active one
                 host, _ = self._get_active_binding(port_id)
 
-            self._port_bindings[port_id][host] = {
+            update = {
                 'host': host,
                 'status': 'ACTIVE',
-                'profile': copy.deepcopy(
-                    body['port'].get('binding:profile') or {},
-                ),
-                'vif_details': port.get('binding:vif_details') or {},
                 'vif_type': port['binding:vif_type'],
                 'vnic_type': port['binding:vnic_type'],
             }
+            if body['port'].get('binding:profile'):
+                update['profile'] = copy.deepcopy(
+                    body['port']['binding:profile'])
+            if body['port'].get('binding:vif_details'):
+                update['vif_details'] = copy.deepcopy(
+                    body['port']['binding:vif_details'])
+            self._port_bindings[port_id][host] = update
 
             # mark any other active bindings as inactive
             self._activate_port_binding(port_id, host)