- [feature] Adding/removing None from a mapped collection

now generates attribute events.  Previously, a None
append would be ignored in some cases.  Related
to [ticket:2229].

- [feature] The presence of None in a mapped collection
now raises an error during flush.   Previously,
None values in collections would be silently ignored.
[ticket:2229]

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/sqlalchemy/orm/unitofwork.py b/lib/sqlalchemy/orm/unitofwork.py
index c0423939f..84c9f647c 100644
--- a/lib/sqlalchemy/orm/unitofwork.py
+++ b/lib/sqlalchemy/orm/unitofwork.py
@@ -29,6 +29,9 @@ def track_cascade_events(descriptor, prop):
         # process "save_update" cascade rules for when
         # an instance is appended to the list of another instance
 
+        if item is None:
+            return
+
         sess = sessionlib._state_session(state)
         if sess:
             prop = state.manager.mapper._props[key]
@@ -40,6 +43,9 @@ def track_cascade_events(descriptor, prop):
         return item
 
     def remove(state, item, initiator):
+        if item is None:
+            return
+
         sess = sessionlib._state_session(state)
         if sess:
             prop = state.manager.mapper._props[key]