- [bug] Continuing [ticket:2566] regarding extra

    state post-flush due to event listeners;
    any states that are marked as "dirty" from an
    attribute perspective, usually via column-attribute
    set events within after_insert(), after_update(),
    etc., will get the "history" flag reset
    in all cases, instead of only those instances
    that were part of the flush.  This has the effect
    that this "dirty" state doesn't carry over
    after the flush and won't result in UPDATE
    statements.   A warning is emitted to this
    effect; the set_committed_state()
    method can be used to assign attributes on objects
    without producing history events. [ticket:2582]

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py
index dcbd6ba7e..70d3bc0bb 100644
--- a/lib/sqlalchemy/orm/session.py
+++ b/lib/sqlalchemy/orm/session.py
@@ -1841,6 +1841,21 @@ class Session(_SessionClassMethods):
 
             flush_context.finalize_flush_changes()
 
+            if not objects and self.identity_map._modified:
+                len_ = len(self.identity_map._modified)
+
+                statelib.InstanceState._commit_all_states(
+                                [(state, state.dict) for state in
+                                        self.identity_map._modified],
+                                instance_dict=self.identity_map)
+                util.warn("Attribute history events accumulated on %d "
+                        "previously clean instances "
+                        "within inner-flush event handlers have been reset, "
+                        "and will not result in database updates. "
+                        "Consider using set_committed_value() within "
+                        "inner-flush event handlers to avoid this warning."
+                                    % len_)
+
             # useful assertions:
             #if not objects:
             #    assert not self.identity_map._modified