diff options
Diffstat (limited to 'lib/sqlalchemy/orm/session.py')
| -rw-r--r-- | lib/sqlalchemy/orm/session.py | 42 |
1 files changed, 24 insertions, 18 deletions
diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py index 5488c3031..359370ab5 100644 --- a/lib/sqlalchemy/orm/session.py +++ b/lib/sqlalchemy/orm/session.py @@ -1920,28 +1920,34 @@ class Session(_SessionClassMethods): key_is_persistent = True if key in self.identity_map: - merged = self.identity_map[key] - elif key_is_persistent and key in _resolve_conflict_map: - merged = _resolve_conflict_map[key] - - elif not load: - if state.modified: - raise sa_exc.InvalidRequestError( - "merge() with load=False option does not support " - "objects marked as 'dirty'. flush() all changes on " - "mapped instances before merging with load=False.") - merged = mapper.class_manager.new_instance() - merged_state = attributes.instance_state(merged) - merged_state.key = key - self._update_impl(merged_state) - new_instance = True - - elif key_is_persistent: - merged = self.query(mapper.class_).get(key[1]) + try: + merged = self.identity_map[key] + except KeyError: + # object was GC'ed right as we checked for it + merged = None else: merged = None if merged is None: + if key_is_persistent and key in _resolve_conflict_map: + merged = _resolve_conflict_map[key] + + elif not load: + if state.modified: + raise sa_exc.InvalidRequestError( + "merge() with load=False option does not support " + "objects marked as 'dirty'. flush() all changes on " + "mapped instances before merging with load=False.") + merged = mapper.class_manager.new_instance() + merged_state = attributes.instance_state(merged) + merged_state.key = key + self._update_impl(merged_state) + new_instance = True + + elif key_is_persistent: + merged = self.query(mapper.class_).get(key[1]) + + if merged is None: merged = mapper.class_manager.new_instance() merged_state = attributes.instance_state(merged) merged_dict = attributes.instance_dict(merged) |