[hibernate-issues] [Hibernate-JIRA] Resolved: (HHH-5280) Exception on unidirectional collection whose elements are owned by several collection: "java.lang.IllegalArgumentException: object is not an instance of declaring class"

Exception on unidirectional collection whose elements are owned by several collection: "java.lang.IllegalArgumentException: object is not an instance of declaring class" ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Key: HHH-5280 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-5280 Project: Hibernate Core Issue Type: Bug Components: core Affects Versions: 3.5.2, 3.6.0 Environment: Hibernate 3.5.2 Db: All? (At least h2 and mysql) Reporter: Benjamin Lerman Assignee: Emmanuel Bernard Priority: Critical Fix For: 3.6.1 Attachments: hibernate-multi-parent.tgz, patch.txt, projectHbBugParentId.zip, test.entity.TestCreate.txt I attach a maven project showing the bug. I have 3 classes, A, B, C with C have a one-to-many unidirectional relation to B and A. B have a one-to-many unidirectional relation to A. Those relations are mapped by foreign keys. The cascading properties for those relations are all save-update,persist For each of those relations, the inverse cardinality is 1 (which means A must be associated with a B and a C, and B must be associated with a C). I create an instance of C that I associate to an instance of B and an instance of A, and I associate the instance of B with the instance of A. I then try to save C, and I get the attached exception. For what I understood the problem is with the method StatefulPersistenceContext.getOwnerId: this method use a cache to retrieve the parent of the instance of A, but because A has 2 different parents (the instance of B and the instance of C), it does not retrieve the right one and try to call a method on the wrong entity.