This request is basically a reopening of HHH-7158.
-Fixing of did successfully solve both attached testmethods, but only the first one was integrated into hibernate matrix tests.
-Fixing of did slightly change the way how natural-id-vales are compared, causing now testmethod2 fail again.
after HHH-7206: (please notice now there has appeared persister.getFactory() as third parameter)
Either revert back to using the isEqual method again with 2 parameters only,
or alternatevely make method
EntityType#isEqual(Object x, Object y, SessionFactoryImplementor factory)
stable against null x,y values as proposed in HHH-7158.
I don't know which one is the better solution, but both solution make the attached testcases go through without fails.