save() on association does not cascade in 4.x/5.x

[yvesf]

Please see the following test for grails-datastore-gorm-test: gist SaveCascadeSpec.groovy

It contains two cases for two relation types:

• ToOne: This one fails in gorm 4.x branch and 5.x branch. It looks like a incomplete logic in NativeEntryEntityPersister
• OneToMany: This one succeeds in gorm 4.x, it fails in 5.x branch.

As it is shown in the test, I assume that a entity with a association where the other end belongsTo should cascade on save. This is what I understood from the 'cascade' help in the docs.

My idea to fix the ToOne is to not only check for empty id but also do the dirty check in the NativeEntryEntityPersister:

// else if (prop instanceof ToOne) { ...
if (tempId == null) {
    if (association.isOwningSide()) {
        tempId = session.persist(associatedObject);
    }
} else if (associatedObject instanceof DirtyCheckable) {
    if (((DirtyCheckable)associatedObject).hasChanged()) {
        tempId = associationPersister.persist(associatedObject);
    }
}

For the OneToMany I have currently no idea how to fix it. I just realized that in the NativeEntityPersister is only checking if the PersistentSet is dirty. This is not the case, it's the entry inside the PersistentSet that is dirty.