HHH-16756 Add test for issue

hibernate-core/src/test/java/org/hibernate/orm/test/bytecode/enhancement/orphan/OrfanRemovalTest.java

@@ -0,0 +1,131 @@
+package org.hibernate.orm.test.bytecode.enhancement.orphan;
+
+import org.hibernate.annotations.DynamicInsert;
+import org.hibernate.annotations.DynamicUpdate;
+import org.hibernate.annotations.Fetch;
+import org.hibernate.annotations.LazyGroup;
+import org.hibernate.annotations.LazyToOne;
+
+import org.hibernate.testing.bytecode.enhancement.BytecodeEnhancerRunner;
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+import org.hibernate.testing.orm.junit.JiraKey;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.OneToOne;
+import jakarta.persistence.Table;
+import jakarta.persistence.Version;
+
+import static jakarta.persistence.CascadeType.ALL;
+import static jakarta.persistence.FetchType.LAZY;
+import static org.hibernate.annotations.FetchMode.SELECT;
+import static org.hibernate.annotations.LazyToOneOption.NO_PROXY;
+import static org.junit.Assert.assertNull;
+
+@RunWith(BytecodeEnhancerRunner.class)
+@JiraKey("HHH-16756")
+public class OrfanRemovalTest extends BaseCoreFunctionalTestCase {
+
+	static final int ENTITY_ID = 1;
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class<?>[] {
+				Entity1.class,
+				Entity2.class
+		};
+	}
+
+	@Before
+	public void setUp() {
+		inTransaction(
+				session -> {
+					Entity1 e1 = new Entity1( ENTITY_ID );
+					Entity2 e2 = new Entity2();
+
+					e1.setChild( e2 );
+
+					e2.setCaseNumber( "TEST" );
+					e2.setParent( e1 );
+
+					session.persist( e1 );
+				}
+		);
+	}
+
+
+	@Test
+	public void hhh16756Test() {
+		inTransaction(
+				session -> {
+					Entity1 e1 = session.byId( Entity1.class ).load( ENTITY_ID );
+					e1.setChild( null );
+
+					session.flush();
+
+					assertNull( session.byId( Entity2.class ).load( ENTITY_ID ) );
+				}
+		);
+	}
+
+	@Entity(name = "Entity1")
+	@Table(name = "entity1")
+	@DynamicInsert
+	@DynamicUpdate
+	public static class Entity1 {
+		@Id
+		protected int id;
+
+		@Version
+		@Column(name = "lock_version", nullable = false, columnDefinition = "smallint")
+		protected int lockVersion;
+
+		@OneToOne(fetch = LAZY, cascade = ALL, orphanRemoval = true, mappedBy = "parent")
+		@LazyToOne(NO_PROXY)
+		@LazyGroup("group2")
+		@Fetch(SELECT)
+		protected Entity2 child;
+
+		public Entity1() {
+		}
+
+		public Entity1(int id) {
+			this.id = id;
+		}
+
+		public void setChild(Entity2 child) {
+			this.child = child;
+		}
+	}
+
+	@Entity(name = "Entity2")
+	@Table(name = "entity2")
+	@DynamicInsert
+	@DynamicUpdate
+	public static class Entity2 {
+		@Id
+		@OneToOne(fetch = LAZY, optional = false)
+		@LazyToOne(NO_PROXY)
+		@LazyGroup("owner")
+		@JoinColumn(name = "parentid", nullable = false, updatable = false, columnDefinition = "smallint")
+		@Fetch(SELECT)
+		protected Entity1 parent;
+
+		@Column(name = "case_number")
+		protected String caseNumber;
+
+		public void setParent(Entity1 parent) {
+			this.parent = parent;
+		}
+
+		public void setCaseNumber(String caseNumber) {
+			this.caseNumber = caseNumber;
+		}
+	}
+
+}