doctrine/mongodb-odm — pull request #220 by z7 (2011-12-28 13:58:35+00:00)
Title: Bug fix in PersistentCollection handling during merge operation.

After serializing/deserializing a document with PersistentCollection(s), initialized collections lose their reference to the DocumentManager and UnitOfWork.
And as a result an error will triggered when trying to clear the collection or do any other operation requiring access to one of these 2 objects.

Another issue is the fact that any collection in a merged document may have different contents than the coresponding document field from the database, so a dirty check is required in order to properly synchronize.