SCM inventory cancel propagation

For manually initiated inventory updates, also cancel the source
project of "sync" type, like jobs do

For automatic inventory updates spawned from source project update,
of launch type "scm", handle contigency cases

awx/main/tests/functional/test_tasks.py

@@ -3,7 +3,7 @@ import mock
 import os
 
 from awx.main.tasks import RunProjectUpdate, RunInventoryUpdate
-from awx.main.models import ProjectUpdate, InventoryUpdate
+from awx.main.models import ProjectUpdate, InventoryUpdate, InventorySource
 
 
 @pytest.fixture
@@ -43,3 +43,32 @@ class TestDependentInventoryUpdate:
             inv_update = InventoryUpdate.objects.first()
             iu_run_mock.assert_called_once_with(inv_update.id)
             assert inv_update.source_project_update_id == proj_update.pk
+
+    def test_dependent_inventory_project_cancel(self, project, inventory):
+        '''
+        Test that dependent inventory updates exhibit good behavior on cancel
+        of the source project update
+        '''
+        task = RunProjectUpdate()
+        proj_update = ProjectUpdate.objects.create(project=project)
+
+        kwargs = dict(
+            source_project=project,
+            source='scm',
+            source_path='inventory_file',
+            update_on_project_update=True,
+            inventory=inventory
+        )
+
+        is1 = InventorySource.objects.create(name="test-scm-inv", **kwargs)
+        is2 = InventorySource.objects.create(name="test-scm-inv2", **kwargs)
+
+        def user_cancels_project(pk):
+            ProjectUpdate.objects.all().update(cancel_flag=True)
+
+        with mock.patch.object(RunInventoryUpdate, 'run') as iu_run_mock:
+            iu_run_mock.side_effect = user_cancels_project
+            task._update_dependent_inventories(proj_update, [is1, is2])
+            # Verify that it bails after 1st update, detecting a cancel
+            assert is2.inventory_updates.count() == 0
+            iu_run_mock.assert_called_once()