JPA2 Lazy Child Collection with orphanRemoval=true deletes 'not-fetched' children

I have a Parent entity that owns(via mappedBy) a FetchType.LAZY Set<Child> with orphanDe开发者_高级运维lete=true.

A client can happily add and remove child rows via the parent's collection getter and their changes are properly committed after an em.merge(parent).

However, if a client merges a parent WITHOUT accessing the child collection, all child rows are deleted on the parent's commit.

The same behavior is exhibited under OpenJPA 2.1.0 and the 2.1.1-20110610.205956-18 snapshot binary.

Any pointers would be appreciated.

An example to illustrate:

@Entity
public class Parent{

    @Column
    private String name;

    @OneToMany(mappedBy="parent", fetch=LAZY, cascade = ALL, orphanRemoval=true)
    private Set<Child> children;

    public String getName(){return name;}
    public void setName(String name){this.name=name;}

    public Set<Child> getChildren(){
        return children;
    }
}

@Entity
public class Child{

    @ManyToOne(optional = false, targetEntity = Parent.class)
    @JoinColumn(name="parent_id", nullable=false)
    private Parent parent;

}

Both entities have @Id and @Version properties declared and implement appropriate hashCode, equals and compareTo methods.

The following client code works perfectly, the parent.name is updated, 1 child is inserted and 1 child is deleted

EntityTransaction eTx=em.getTransaction();
eTx.begin();

Parent par=em.find(Parent.class, parId);
    //PersistenceUnitUtil.isLoaded(par) returns true
    //PersistenceUnitUtil.isLoaded(par, "children") returns false
Collection<Child> children=par.getChildren();
    //PersistenceUnitUtil.isLoaded(par, "children") returns true
Child child = children.iterator().next();
par.getChildren().remove(child);
par.getChildren().add(new Child(par, "I'm New"));
par.setName("I am Updated");
par=em.merge(par);

eTx.commit();

The following code will issue delete commands for each of the parent's children:

EntityTransaction eTx=em.getTransaction();
eTx.begin();

Parent par=em.find(Parent.class, parId);
   //PersistenceUnitUtil.isLoaded(par) here returns true, and
   //PersistenceUnitUtil.isLoaded(par, "children") returns false
par.setName("I am Updated");
par=em.merge(par);
eTx.commit();

Just don't call merge. There's no need for it. Within the scope of a transaction, changes made to an object that was looked up within that transaction will be persisted unless the object is detached.