Inconsistent behavior when using Session.get() with multiple subclasses ----------------------------------------------------------------------- Key: HHH-1460 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1460 Project: Hibernate Core Issue Type: Bug Components: core Affects Versions: 3.1.2 Environment: Hibernate 3.1.2 HSQLDB 1.8.0.2 Java 1.5.0_05-b05 Reporter: Seth Fitzsimmons Assignee: Steve Ebersole Fix For: 3.2.1 Attachments: ClassCastException.zip Session.get() loads a cached instance of an alternate subclass with the same PK after that subclass has been loaded directly (throwing a ClassCastException where null was expected). When attempting to load it without prior loading, null is returned, as expected. Client and Partner both extend person and have discriminator values of 1 and 2, respectively. There is a single entry in the database (a Client) with a PK of 0. This should be null: Partner partner = (Partner) getSession().get(Partner.class, 0); assertNull(partner); It is. However, if the Client is loaded first, Hibernate will attempt to return a Partner (as a Client) where it should not exist: Client client = (Client) getSession().get(Client.class, 0); assertNotNull(client); // this should be null, not return a Client object (resulting in a ClassCastException) Partner partner = (Partner) getSession().get(Partner.class, 0); assertNull(partner);