Added check for emptyness where in_ is being used

All the Neutron code was scanned for places where in_ is being used
and added checks to ensure that the input is not an empty sequence.

Change-Id: I1e27f94ea350ce1dfabdd7eb14e4397ca29e8eb7
Closes-Bug:1264579

neutron/db/common_db_mixin.py

@@ -134,6 +134,9 @@ class CommonDbMixin(object):
             for key, value in filters.iteritems():
                 column = getattr(model, key, None)
                 if column:
+                    if not value:
+                        query = query.filter(sql.false())
+                        return query
                     query = query.filter(column.in_(value))
             for _name, hooks in self._model_query_hooks.get(model,
                                                             {}).iteritems():

neutron/db/l3_agentschedulers_db.py

@@ -360,6 +360,8 @@ class L3AgentSchedulerDbMixin(l3agentscheduler.L3AgentSchedulerPluginBase,
             for key, value in filters.iteritems():
                 column = getattr(agents_db.Agent, key, None)
                 if column:
+                    if not value:
+                        return []
                     query = query.filter(column.in_(value))
 
             agent_modes = filters.get('agent_modes', [])
@@ -481,6 +483,8 @@ class L3AgentSchedulerDbMixin(l3agentscheduler.L3AgentSchedulerPluginBase,
 
     def get_l3_agent_with_min_routers(self, context, agent_ids):
         """Return l3 agent with the least number of routers."""
+        if not agent_ids:
+            return None
         query = context.session.query(
             agents_db.Agent,
             func.count(

neutron/db/l3_dvr_db.py

@@ -365,6 +365,8 @@ class L3_NAT_with_dvr_db_mixin(l3_db.L3_NAT_db_mixin,
 
     def _build_routers_list(self, context, routers, gw_ports):
         # Perform a single query up front for all routers
+        if not routers:
+            return []
         router_ids = [r['id'] for r in routers]
         snat_binding = l3_dvrsched_db.CentralizedSnatL3AgentBinding
         query = (context.session.query(snat_binding).

neutron/db/l3_hamode_db.py

@@ -435,6 +435,8 @@ class L3_HA_NAT_db_mixin(l3_dvr_db.L3_NAT_with_dvr_db_mixin):
                 self._delete_ha_interfaces(context, router_db.id)
 
     def get_ha_router_port_bindings(self, context, router_ids, host=None):
+        if not router_ids:
+            return []
         query = context.session.query(L3HARouterAgentPortBinding)
 
         if host:

neutron/db/l3_hascheduler_db.py

@@ -49,6 +49,8 @@ class L3_HA_scheduler_db_mixin(l3_sch_db.L3AgentSchedulerDbMixin):
         return query
 
     def get_l3_agents_ordered_by_num_routers(self, context, agent_ids):
+        if not agent_ids:
+            return []
         query = (context.session.query(agents_db.Agent, func.count(
             l3_sch_db.RouterL3AgentBinding.router_id).label('count')).
             outerjoin(l3_sch_db.RouterL3AgentBinding).

neutron/plugins/cisco/db/n1kv_db_v2.py

@@ -1004,7 +1004,9 @@ class NetworkProfile_db_mixin(object):
         net_profile_ids = (db_session.query(n1kv_models_v2.ProfileBinding.
                                             profile_id).
                            filter_by(tenant_id=tenant_id).
-                           filter_by(profile_type=c_const.NETWORK))
+                           filter_by(profile_type=c_const.NETWORK).all())
+        if not net_profile_ids:
+            return []
         network_profiles = (db_session.query(model).filter(model.id.in_(
             pid[0] for pid in net_profile_ids)))
         return [self._make_network_profile_dict(p) for p in network_profiles]
@@ -1464,6 +1466,8 @@ class PolicyProfile_db_mixin(object):
                        ProfileBinding.profile_id)
                        .filter_by(tenant_id=tenant_id).
                        filter_by(profile_type=c_const.POLICY).all())
+        if not profile_ids:
+            return []
         profiles = db_session.query(model).filter(model.id.in_(
             pid[0] for pid in profile_ids))
         return [self._make_policy_profile_dict(p) for p in profiles]
@@ -1637,12 +1641,13 @@ class PolicyProfile_db_mixin(object):
                                        n1kv_models_v2.ProfileBinding.
                                        profile_type == c_const.POLICY)))
             b_set = set(i.profile_id for i in b_set_q)
-            (db_session.query(n1kv_models_v2.ProfileBinding).
-             filter(sql.and_(n1kv_models_v2.ProfileBinding.profile_id.
-                             in_(a_set & b_set),
-                             n1kv_models_v2.ProfileBinding.tenant_id ==
-                             c_const.TENANT_ID_NOT_SET)).
-             delete(synchronize_session="fetch"))
+            if a_set & b_set:
+                (db_session.query(n1kv_models_v2.ProfileBinding).
+                 filter(sql.and_(n1kv_models_v2.ProfileBinding.profile_id.
+                                 in_(a_set & b_set),
+                                 n1kv_models_v2.ProfileBinding.tenant_id ==
+                                 c_const.TENANT_ID_NOT_SET)).
+                 delete(synchronize_session="fetch"))
 
     def _add_policy_profile(self,
                             policy_profile_name,

neutron/plugins/ml2/drivers/type_vxlan.py

@@ -120,9 +120,10 @@ class VxlanTypeDriver(type_tunnel.TunnelTypeDriver):
             chunked_vnis = (vnis_to_remove[i:i + bulk_size] for i in
                             range(0, len(vnis_to_remove), bulk_size))
             for vni_list in chunked_vnis:
-                session.query(VxlanAllocation).filter(
-                    VxlanAllocation.vxlan_vni.in_(vni_list)).delete(
-                        synchronize_session=False)
+                if vni_list:
+                    session.query(VxlanAllocation).filter(
+                        VxlanAllocation.vxlan_vni.in_(vni_list)).delete(
+                            synchronize_session=False)
             # collect vnis that need to be added
             vnis = list(vxlan_vnis - existing_vnis)
             chunked_vnis = (vnis[i:i + bulk_size] for i in