This fix seems to cause a regression that leads to non-optional OneToOne's to always be fetched eagerly, because isNullable() returns foreignKeyDirection == FROM_PARENT, which is not set any more :

        if ( value.isReferenceToPrimaryKey() ) {
            value.setForeignKeyType( ForeignKeyDirection.TO_PARENT );
        }
        else {
            value.setForeignKeyType(
                    value.isConstrained()
                            ? ForeignKeyDirection.FROM_PARENT
                            : ForeignKeyDirection.TO_PARENT
            );
        }

Therefore,

• foreignKeyDirection= ForeignKeyDirection.TO_PARENT
• OneToOneType.isNullable returns true (used to be false because non optional/constrained)
• A proxy will never be created