Bug 354822

Description Tor-Einar Jarnbjo 2011-08-16 09:16:46 EDT

Build Identifier: 2.2.0

The fix for Bug 327900 does not work properly if interface aliases are configured for the persistent classes. Consider e.g. the classes A and B with "B extends A" and their interface aliases IA and IB.

If I make a query for IB and an instance of B is found, the following expression in IdentityMapManager evaluates to false:

boolean readSubclassesOrNoInheritance = (!descriptor.hasInheritance() ||
descriptor.getInheritancePolicy().shouldReadSubclasses());

descriptor is here the class descriptor of B, with:

- hasInheritance() is true, since an InheritancePolicy instance is available
- shouldReadSubclasses() is false, since there are no further subclasses of B

Later in the same method, readSubclassesOrNoInheritance is used like this:

if ((object.getClass() == theClass) || (readSubclassesOrNoInheritance &&
(theClass.isInstance(object)))) {

We now have the issue that object.getClass() returns B.class, while theClass
is IB.class. Since readSubclassesOrNoInheritance is false, the isInstance check
(IB.class.isInstance(B.class) would have evaluated to true) does not cover the
interface alias, as it did before this fix was applied.


Reproducible: Always

Steps to Reproduce:
1. Create two inherited entities A and B, where B extends A. Let B have an interface alias IB.
2. Create an instance of B with some data, so that it can be queried from the identity map cache. Do not persist or commit to the database.
3. Run a query for IB with an expression matching the data of the newly created B instance. The expected behaviour is that the cached instance of B is returned, however the query does not return any results.