HHH-6813 Corrected EntityType#getRHSUniqueKeyPropertyName() and added

regression test.

hibernate-core/src/main/java/org/hibernate/type/EntityType.java

@@ -201,7 +201,9 @@ public boolean isReferenceToPrimaryKey() {
 	}
 
 	public String getRHSUniqueKeyPropertyName() {
-		return uniqueKeyPropertyName;
+		// Return null if this type references a PK.  This is important for
+		// associations' use of mappedBy referring to a derived ID.
+		return referenceToPrimaryKey ? null : uniqueKeyPropertyName;
 	}
 
 	public String getLHSPropertyName() {

hibernate-core/src/test/java/org/hibernate/test/annotations/derivedidentities/bidirectional/OneToOneWithDerivedIdentityTest.java

@@ -26,6 +26,9 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
+import java.util.List;
+
+import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.testing.TestForIssue;
 import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
@@ -80,11 +83,50 @@ public void testSelectWithDerivedId() {
 		s.close();
 	}
 
+	@Test
+	@TestForIssue(jiraKey = "HHH-6813")
+	// Regression test utilizing multiple types of queries.
+	public void testCase() {
+		Session s = openSession();
+		s.getTransaction().begin();
+
+		Person p = new Person();
+		p.setName( "Alfio" );
+		PersonInfo pi = new PersonInfo();
+		pi.setId( p );
+		pi.setInfo( "Some information" );
+		s.persist( p );
+		s.persist( pi );
+
+		s.getTransaction().commit();
+		s.clear();
+
+		s.getTransaction().begin();
+
+		Query q = s.getNamedQuery( "PersonQuery" );
+		List<Person> persons = q.list();
+		assertEquals( persons.size(), 1 );
+		assertEquals( persons.get( 0 ).getName(), "Alfio" );
+
+		s.getTransaction().commit();
+		s.clear();
+
+		s.getTransaction().begin();
+
+		p = (Person) s.get( Person.class, persons.get( 0 ).getId() );
+		assertEquals( p.getName(), "Alfio" );
+
+		s.getTransaction().commit();
+		s.close();
+	}
+
 	@Override
 	protected Class<?>[] getAnnotatedClasses() {
 		return new Class<?>[] {
 				Foo.class,
-				Bar.class
+				Bar.class,
+				Person.class,
+				PersonInfo.class
 		};
 	}
 

hibernate-core/src/test/java/org/hibernate/test/annotations/derivedidentities/bidirectional/Person.java

@@ -0,0 +1,77 @@
+package org.hibernate.test.annotations.derivedidentities.bidirectional;
+
+import java.io.Serializable;
+import javax.persistence.Basic;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.NamedQuery;
+import javax.persistence.OneToOne;
+
+@Entity
+@NamedQuery(name="PersonQuery", query="SELECT p FROM Person p")
+public class Person
+  implements Serializable
+{
+  private static final long serialVersionUID = 1L;
+
+  @Id
+  @GeneratedValue(strategy=GenerationType.AUTO)
+  private Integer id;
+
+  @Basic
+  private String name;
+
+  @OneToOne(mappedBy="id")
+  private PersonInfo personInfo;
+
+  public Integer getId()
+  {
+    return this.id;
+  }
+
+  public void setId(Integer id) {
+    this.id = id;
+  }
+
+  public String getName() {
+    return this.name;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+
+  public int hashCode()
+  {
+    int hash = 0;
+    hash += (this.id != null ? this.id.hashCode() : 0);
+    return hash;
+  }
+
+  public boolean equals(Object object)
+  {
+    if (!(object instanceof Person)) {
+      return false;
+    }
+    Person other = (Person)object;
+
+    return ((this.id != null) || (other.id == null)) && ((this.id == null) || (this.id.equals(other.id)));
+  }
+
+  public String toString()
+  {
+    return "nogroup.hibertest.Person[ id=" + this.id + " ]";
+  }
+
+  public PersonInfo getPersonInfo()
+  {
+    return this.personInfo;
+  }
+
+  public void setPersonInfo(PersonInfo personInfo)
+  {
+    this.personInfo = personInfo;
+  }
+}

hibernate-core/src/test/java/org/hibernate/test/annotations/derivedidentities/bidirectional/PersonInfo.java

@@ -0,0 +1,60 @@
+package org.hibernate.test.annotations.derivedidentities.bidirectional;
+
+import java.io.Serializable;
+import javax.persistence.Basic;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.OneToOne;
+
+@Entity
+public class PersonInfo
+  implements Serializable
+{
+  private static final long serialVersionUID = 1L;
+
+  @Id
+  @OneToOne
+  private Person id;
+
+  @Basic
+  private String info;
+
+  public Person getId()
+  {
+    return this.id;
+  }
+
+  public void setId(Person id) {
+    this.id = id;
+  }
+
+  public String getInfo() {
+    return this.info;
+  }
+
+  public void setInfo(String info) {
+    this.info = info;
+  }
+
+  public int hashCode()
+  {
+    int hash = 0;
+    hash += (this.id != null ? this.id.hashCode() : 0);
+    return hash;
+  }
+
+  public boolean equals(Object object)
+  {
+    if (!(object instanceof PersonInfo)) {
+      return false;
+    }
+    PersonInfo other = (PersonInfo)object;
+
+    return ((this.id != null) || (other.id == null)) && ((this.id == null) || (this.id.equals(other.id)));
+  }
+
+  public String toString()
+  {
+    return "nogroup.hibertest.PersonInfo[ id=" + this.id + " ]";
+  }
+}