I can confirm that running the provided test case against 5.3.0.Final and 5.3.1.Final fails, but the version of this test case that Vlad copied to our codebase does not fail. Ever.

I simplified the test case as much as I could so that I can investigate further: https://github.com/yrodiere/hibernate-test-case-templates/tree/HHH-12594

Interestingly, dropping the "EAGER" loading on the inverse side of the association makes the problem disappear.

I will investigate further this afternoon.