Don't override sections in deep_update

When you comment all the elements in a YAML mapping, you end up with
None instead of an empty mapping, which can have bad side effect when
handling multiple environemnents. Let's handle that by ignoring the
latest None value.

Change-Id: I77ffabeb8d4cd2886ef4f41351e42ebe487b5d4b

1 files changed, 45 insertions, 0 deletions

diff --git a/heatclient/tests/unit/test_template_utils.py b/heatclient/tests/unit/test_template_utils.py
index a48e0b3..01cfa13 100644
--- a/heatclient/tests/unit/test_template_utils.py
+++ b/heatclient/tests/unit/test_template_utils.py
@@ -448,6 +448,51 @@ class ShellEnvironmentTest(testtools.TestCase):
 
         ])
 
+    @mock.patch('six.moves.urllib.request.urlopen')
+    def test_process_multiple_environments_empty_registry(self, mock_url):
+        # Setup
+        env_file1 = '/home/my/dir/env1.yaml'
+        env_file2 = '/home/my/dir/env2.yaml'
+
+        env1 = b'''
+        resource_registry:
+          "OS::Thingy1": "file:///home/b/a.yaml"
+        '''
+        env2 = b'''
+        resource_registry:
+        '''
+        mock_url.side_effect = [six.BytesIO(env1),
+                                six.BytesIO(self.template_a),
+                                six.BytesIO(self.template_a),
+                                six.BytesIO(env2)]
+
+        # Test
+        env_file_list = []
+        files, env = template_utils.process_multiple_environments_and_files(
+            [env_file1, env_file2], env_list_tracker=env_file_list)
+
+        # Verify
+        expected_env = {
+            'resource_registry': {'OS::Thingy1': 'file:///home/b/a.yaml'}}
+        self.assertEqual(expected_env, env)
+
+        self.assertEqual(self.template_a.decode('utf-8'),
+                         files['file:///home/b/a.yaml'])
+
+        self.assertEqual(['file:///home/my/dir/env1.yaml',
+                          'file:///home/my/dir/env2.yaml'], env_file_list)
+        self.assertIn('file:///home/my/dir/env1.yaml', files)
+        self.assertIn('file:///home/my/dir/env2.yaml', files)
+        self.assertEqual(expected_env,
+                         json.loads(files['file:///home/my/dir/env1.yaml']))
+        mock_url.assert_has_calls([
+            mock.call('file://%s' % env_file1),
+            mock.call('file:///home/b/a.yaml'),
+            mock.call('file:///home/b/a.yaml'),
+            mock.call('file://%s' % env_file2),
+
+        ])
+
     def test_global_files(self):
         url = 'file:///home/b/a.yaml'
         env = '''