Copy the env to the backup stack in failed update

When an update fails, we currently update the environment of the stack
to contain both the new and old parameters and types. Unfortunately we
don't do that for the backup stack which is reused. This patch adds the
environment change.

Change-Id: I4dc5dd35e4aeee498dd8960a1000913e97b924d5
Closes-Bug: 1508096
(cherry picked from commit 88da460316
                       and 13c6891070)

heat/engine/stack.py

@@ -980,6 +980,8 @@ class Stack(collections.Mapping):
             existing_params.load(newstack.t.env.user_env_as_dict())
             self.t.env = existing_params
             self.t.store(self.context)
+            backup_stack.t.env = existing_params
+            backup_stack.t.store(self.context)
         self.store()
         lifecycle_plugin_utils.do_post_ops(self.context, self,
                                            newstack, action,

heat_integrationtests/functional/test_create_update.py

@@ -384,3 +384,35 @@ resources:
             stack_identifier,
             template=self.update_userdata_template,
             parameters=parms_updated)
+
+    def test_stack_update_with_new_env(self):
+        """Update handles new resource types in the environment.
+
+        If a resource type appears during an update and the update fails,
+        retrying the update is able to find the type properly in the
+        environment.
+        """
+        stack_identifier = self.stack_create(
+            template=test_template_one_resource)
+
+        # Update with a new resource and make the update fails
+        template = _change_rsrc_properties(test_template_one_resource,
+                                           ['test1'], {'fail': True})
+        template['resources']['test2'] = {'type': 'My::TestResource'}
+        template['resources']['test1']['depends_on'] = 'test2'
+        env = {'resource_registry':
+               {'My::TestResource': 'OS::Heat::TestResource'}}
+        self.update_stack(stack_identifier,
+                          template=template,
+                          environment=env,
+                          expected_status='UPDATE_FAILED')
+
+        # Fixing the template should fix the stack
+        template = _change_rsrc_properties(template,
+                                           ['test1'], {'fail': False})
+        self.update_stack(stack_identifier,
+                          template=template,
+                          environment=env)
+        self.assertEqual({'test1': 'OS::Heat::TestResource',
+                          'test2': 'My::TestResource'},
+                         self.list_resources(stack_identifier))