new: if the parent cannot be found, don't continue with the child

ckanext/datajson/datajson.py

@@ -509,7 +509,7 @@ def import_stage(self, harvest_object):
                     if parent is not None:
                         parent_pkg_id = parent['id']
                     else:
-                        parent_pkg_id = None
+                        return []
 
             if extra.key.startswith('catalog_'):
                 catalog_extras[extra.key] = extra.value