HHH-16106 Add test for issue

hibernate-core/src/test/java/org/hibernate/orm/test/batch/BatchPostLoadTest.java

@@ -0,0 +1,123 @@
+package org.hibernate.orm.test.batch;
+
+import org.hibernate.annotations.BatchSize;
+
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.orm.junit.EntityManagerFactoryScope;
+import org.hibernate.testing.orm.junit.Jpa;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.PostLoad;
+import jakarta.persistence.criteria.CriteriaBuilder;
+import jakarta.persistence.criteria.CriteriaQuery;
+import jakarta.persistence.criteria.Root;
+
+import static org.junit.Assert.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@Jpa(
+		annotatedClasses = {
+				BatchPostLoadTest.MyEntity1.class,
+				BatchPostLoadTest.MyEntity2.class
+		}
+)
+@TestForIssue(jiraKey = "HHH-16106")
+public class BatchPostLoadTest {
+
+	private static final Long MY_ENTITY_1_ID = 1l;
+
+	@BeforeAll
+	public void setUp(EntityManagerFactoryScope scope) {
+		scope.inTransaction(
+				entityManager -> {
+					MyEntity2 entity2 = new MyEntity2( 2l );
+					entityManager.persist( entity2 );
+
+					MyEntity1 entity1 = new MyEntity1( MY_ENTITY_1_ID, entity2 );
+					entityManager.persist( entity1 );
+
+					Long entity1Id = entity1.getId();
+					assertEquals( entity1Id, entity1.getId() );
+				}
+		);
+	}
+
+	@Test
+	public void testIt(EntityManagerFactoryScope scope) {
+		scope.inTransaction(
+				entityManager -> {
+					CriteriaBuilder builder = entityManager.getCriteriaBuilder();
+					CriteriaQuery<MyEntity1> criteria = builder.createQuery( MyEntity1.class );
+					Root<MyEntity1> root = criteria.from( MyEntity1.class );
+					criteria.select( root );
+					MyEntity1 entity1 = entityManager.createQuery( criteria ).getResultList().get( 0 );
+					assertEquals( MY_ENTITY_1_ID, entity1.getId() );
+					assertNotNull( entity1.getRef() );
+				}
+		);
+	}
+
+	@Entity
+	public static class MyEntity1 {
+		@Id
+		private Long id;
+
+		private Long version;
+
+		@ManyToOne
+		@JoinColumn(name = "ref")
+		private MyEntity2 ref;
+
+		public MyEntity1() {
+		}
+
+		public MyEntity1(Long id, MyEntity2 ref) {
+			this.id = id;
+			this.ref = ref;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		public Long getVersion() {
+			return version;
+		}
+
+		public MyEntity2 getRef() {
+			return ref;
+		}
+
+		@PostLoad
+		public void test() {
+			assertNotNull( getRef() );
+		}
+	}
+
+	@Entity
+	@BatchSize(size = 100)
+	public static class MyEntity2 {
+		@Id
+		private Long id;
+
+		private String name;
+
+		public MyEntity2() {
+		}
+
+		public MyEntity2(Long id) {
+			this.id = id;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+	}
+
+}