Add support for "bulk-delete" of Person table

tailbone/views/master.py

@@ -1855,7 +1855,7 @@ class MasterView(View):
     def bulk_delete_objects(self, session, objects, progress=None):
 
         def delete(obj, i):
-            session.delete(obj)
+            self.delete_instance(obj)
             if i % 1000 == 0:
                 session.flush()
 
@@ -3142,10 +3142,14 @@ class MasterView(View):
         """
         Delete the instance, or mark it as deleted, or whatever you need to do.
         """
+        # note, we don't use self.Session here, in case we're being called from
+        # a separate (bulk-delete) thread
+        session = orm.object_session(instance)
+        session.delete(instance)
+
         # Flush immediately to force any pending integrity errors etc.; that
         # way we don't set flash message until we know we have success.
-        self.Session.delete(instance)
-        self.Session.flush()
+        session.flush()
 
     def get_after_delete_url(self, instance):
         """