don't export draft children of orphaned drafted (TNL-923)

cms/djangoapps/contentstore/tests/test_contentstore.py

@@ -260,6 +260,8 @@ class ImportRequiredTestCases(ContentStoreTestCase):
         # and assert that they contain the created modules
         self.assertIn(self.DRAFT_HTML + ".xml", draft_dir.listdir('html'))
         self.assertIn(self.DRAFT_VIDEO + ".xml", draft_dir.listdir('video'))
+        # and assert the child of the orphaned draft wasn't exported
+        self.assertNotIn(self.ORPHAN_DRAFT_HTML + ".xml", draft_dir.listdir('html'))
 
         # check for grading_policy.json
         filesystem = OSFS(root_dir / 'test_export/policies/2012_Fall')

cms/djangoapps/contentstore/tests/utils.py

@@ -138,6 +138,8 @@ class CourseTestCase(ModuleStoreTestCase):
         self.store.update_item(self.course, self.user.id)
 
     TEST_VERTICAL = 'vertical_test'
+    ORPHAN_DRAFT_VERTICAL = 'orphan_draft_vertical'
+    ORPHAN_DRAFT_HTML = 'orphan_draft_html'
     PRIVATE_VERTICAL = 'a_private_vertical'
     PUBLISHED_VERTICAL = 'a_published_vertical'
     SEQUENTIAL = 'vertical_sequential'
@@ -162,6 +164,18 @@ class CourseTestCase(ModuleStoreTestCase):
         self.assertEqual(orphan_vertical.location.name, 'no_references')
         self.assertEqual(len(orphan_vertical.children), len(vertical.children))
 
+        # create an orphan vertical and html; we already don't try to import
+        # the orphaned vertical, but we should make sure we don't import
+        # the orphaned vertical's child html, too
+        orphan_draft_vertical = self.store.create_item(
+            self.user.id, course_id, 'vertical', self.ORPHAN_DRAFT_VERTICAL
+        )
+        orphan_draft_html = self.store.create_item(
+            self.user.id, course_id, 'html', self.ORPHAN_DRAFT_HTML
+        )
+        orphan_draft_vertical.children.append(orphan_draft_html.location)
+        self.store.update_item(orphan_draft_vertical, self.user.id)
+
         # create a Draft vertical
         vertical = self.store.get_item(course_id.make_usage_key('vertical', self.TEST_VERTICAL), depth=1)
         draft_vertical = self.store.convert_to_draft(vertical.location, self.user.id)

common/lib/xmodule/xmodule/modulestore/xml_exporter.py

@@ -131,15 +131,18 @@ def export_to_xml(modulestore, contentstore, course_key, root_dir, course_dir):
                             draft_module.location,
                             revision=ModuleStoreEnum.RevisionOption.draft_preferred
                         )
-                        # Don't try to export orphaned items.
+
+                        # if module has no parent, set its parent_url to `None`
+                        parent_url = None
                         if parent_loc is not None:
-                            logging.debug('parent_loc = {0}'.format(parent_loc))
+                            parent_url = parent_loc.to_deprecated_string()
+
                         draft_node = draft_node_constructor(
                             draft_module,
                             location=draft_module.location,
                             url=draft_module.location.to_deprecated_string(),
                             parent_location=parent_loc,
-                                parent_url=parent_loc.to_deprecated_string(),
+                            parent_url=parent_url,
                         )
 
                         draft_node_list.append(draft_node)
@@ -153,6 +156,13 @@ def export_to_xml(modulestore, contentstore, course_key, root_dir, course_dir):
                         if not hasattr(draft_node.module, 'xml_attributes'):
                             draft_node.module.xml_attributes = {}
 
+                        # Don't try to export orphaned items
+                        # and their descendents
+                        if draft_node.parent_location is None:
+                            continue
+
+                        logging.debug('parent_loc = {0}'.format(draft_node.parent_location))
+
                         draft_node.module.xml_attributes['parent_url'] = draft_node.parent_url
                         parent = modulestore.get_item(draft_node.parent_location)
                         index = parent.children.index(draft_node.module.location)