Fix wrong use of list of dict in _check_driver_to_bind

From [1], the segments_to_bind should be a list of dict, so the
"level.segment_id in segments_to_bind" will never work.

This patch extracts a set of segment ids and uses the set in the
if condition.

[1] https://goo.gl/yKYSTA

Change-Id: I58f1d128e6cd79546d84f7d5bfcb026affc4fc5e
Closes-bug: #1524356

neutron/plugins/ml2/managers.py

@@ -764,9 +764,11 @@ class MechanismManager(stevedore.named.NamedExtensionManager):
         # level to one of the segments we are currently trying to
         # bind. Note that it is OK for the same driver to bind at
         # multiple levels using different segments.
+        segment_ids_to_bind = {s[api.SEGMENTATION_ID]
+                               for s in segments_to_bind}
         for level in binding_levels:
             if (level.driver == driver and
-                level.segment_id in segments_to_bind):
+                level.segment_id in segment_ids_to_bind):
                 return False
         return True
 

neutron/tests/unit/plugins/ml2/test_managers.py

@@ -0,0 +1,38 @@
+# Copyright (c) 2016 IBM Corp.
+#
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import mock
+
+from neutron.plugins.ml2 import driver_api as api
+from neutron.plugins.ml2 import managers
+from neutron.tests import base
+
+
+class TestManagers(base.BaseTestCase):
+
+    def test__check_driver_to_bind(self):
+        manager = managers.MechanismManager()
+        bindinglevel = mock.Mock()
+        bindinglevel.driver = 'fake_driver'
+        bindinglevel.segment_id = 'fake_seg_id'
+        binding_levels = [bindinglevel]
+        segments_to_bind = [{api.SEGMENTATION_ID: 'fake_seg_id'}]
+        self.assertFalse(manager._check_driver_to_bind(
+            'fake_driver', segments_to_bind, binding_levels))
+
+        bindinglevel.segment_id = 'fake_seg_id1'
+        self.assertTrue(manager._check_driver_to_bind(
+            'fake_driver', segments_to_bind, binding_levels))