Left Join Fetch on Embeddable ElementColection fails & NamedQuery with QueryHints.REFRESH fails to execute

[jGauravGupta]

Fixes issue 1:
JPA Left Join Fetch on Embeddable ElementColection fails
#858

Fixes issue 2:
When defining a NamedQuery that has EclipseLink hints, the query fails with an exception

Exception [EclipseLink-7081] (Eclipse Persistence Services - 2.7.6.payara-p1): org.eclipse.persistence.exceptions.ValidationException
Exception Description: The aggregate object [class be.rubus.payara.support.ticket1455.model.Tag] cannot be directly registered in the UnitOfWork.  It must be associated with the source (owner) object.
	at org.eclipse.persistence.exceptions.ValidationException.cannotRegisterAggregateObjectInUnitOfWork(ValidationException.java:622)

The offending NamedQuery, org.eclipse.persistence.config.QueryHints

@NamedQuery(
        name = "getAllBlogPosts_fail",
        query = "SELECT i FROM BlogPost i",
        hints = {
                @QueryHint(
                        name = QueryHints.REFRESH,
                        value = HintValues.TRUE
                ),
                @QueryHint(
                        name = QueryHints.LEFT_FETCH,
                        value = "i.tags"
                )
        }
)

Sample test app:
fish-406.zip

[lukasj]

Needs a test, reliance on NPE being thrown is not an acceptable solution.

[t-beckmann]

Should be fixed at the origin of failure.

[t-beckmann]

Can you elaborate why this is fixing the issue? Technically I see you are stopping the exception from being thrown, of course. Is this a try-and-error fix, or some deeper understanding? To me it seems the method should not have been called in the first place for those aggregates.