From a4dc0b09a97c001443973d66fe18b68020726d76 Mon Sep 17 00:00:00 2001
From: Andrea Boriero <andrea@hibernate.org>
Date: Wed, 10 Jan 2024 16:01:41 +0100
Subject: [PATCH] HHH-17634 Add test for issue

---
 ...ociationsAndGeneratedValuesMerge2Test.java | 117 ++++++++++++++++++
 .../orm/test/merge/SimpleMergeTest.java       |  62 ++++++++++
 2 files changed, 179 insertions(+)
 create mode 100644 hibernate-core/src/test/java/org/hibernate/orm/test/merge/CompositeIdWithAssociationsAndGeneratedValuesMerge2Test.java
 create mode 100644 hibernate-core/src/test/java/org/hibernate/orm/test/merge/SimpleMergeTest.java

diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/merge/CompositeIdWithAssociationsAndGeneratedValuesMerge2Test.java b/hibernate-core/src/test/java/org/hibernate/orm/test/merge/CompositeIdWithAssociationsAndGeneratedValuesMerge2Test.java
new file mode 100644
index 0000000000..9a2edbc513
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/merge/CompositeIdWithAssociationsAndGeneratedValuesMerge2Test.java
@@ -0,0 +1,117 @@
+package org.hibernate.orm.test.merge;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.JiraKey;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Column;
+import jakarta.persistence.Embeddable;
+import jakarta.persistence.EmbeddedId;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+@DomainModel(
+		annotatedClasses = {
+				CompositeIdWithAssociationsAndGeneratedValuesMerge2Test.Middle.class,
+				CompositeIdWithAssociationsAndGeneratedValuesMerge2Test.Bottom.class
+		}
+)
+@SessionFactory
+@JiraKey( "HHH-17634" )
+public class CompositeIdWithAssociationsAndGeneratedValuesMerge2Test {
+
+	@Test
+	public void testMerge(SessionFactoryScope scope) {
+
+		scope.inTransaction(
+				session -> {
+					Middle m1 = new Middle( "Middle" );
+					Bottom bottom = new Bottom( m1, 0, "Bottom" );
+					Middle merge = session.merge( m1 );
+					assertThat( merge.getId() ).isNotNull();
+					assertThat( m1.getId() ).isNull();
+				}
+		);
+	}
+
+	@Entity(name = "Middle")
+	@Table(name = "middle_table")
+	public static class Middle {
+		@Id
+		@GeneratedValue
+		private Long id;
+
+		private String name;
+
+		@OneToMany(mappedBy = "middle", cascade = { CascadeType.MERGE, CascadeType.PERSIST })
+		private List<Bottom> bottoms;
+
+		public Middle() {
+		}
+
+		public Middle(String name) {
+			this.name = name;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+
+		public String getName() {
+			return name;
+		}
+
+
+		public List<Bottom> getBottoms() {
+			return bottoms;
+		}
+
+
+		public void addBottom(Bottom bottom) {
+			if ( bottoms == null ) {
+				bottoms = new ArrayList<>();
+			}
+			bottoms.add( bottom );
+		}
+	}
+
+	@Entity(name = "Bottom")
+	@Table(name = "bottom_table")
+	public static class Bottom {
+		@Id
+		@ManyToOne(optional = false, cascade = CascadeType.MERGE)
+		@JoinColumn(name = "middle_id", nullable = false)
+		private Middle middle;
+
+		@Id
+		@Column(name = "type_column")
+		private Integer type;
+
+		private String note;
+
+		public Bottom() {
+		}
+
+		public Bottom(Middle middle, Integer type,String note) {
+			this.middle = middle;
+			this.middle.addBottom( this );
+			this.type = type;
+			this.note = note;
+		}
+	}
+
+}
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/merge/SimpleMergeTest.java b/hibernate-core/src/test/java/org/hibernate/orm/test/merge/SimpleMergeTest.java
new file mode 100644
index 0000000000..cc0b321323
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/merge/SimpleMergeTest.java
@@ -0,0 +1,62 @@
+package org.hibernate.orm.test.merge;
+
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.JiraKey;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DomainModel(
+		annotatedClasses = {
+				SimpleMergeTest.MyEntity.class
+		}
+)
+@SessionFactory
+@JiraKey( "HHH-17634" )
+public class SimpleMergeTest {
+
+	@Test
+	public void testMergeNewEntity(SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					MyEntity newEntity = new MyEntity();
+
+					assertThat( newEntity.getId() ).isNull();
+
+					MyEntity mergedEntity = session.merge( newEntity );
+					assertThat( mergedEntity ).isNotSameAs( newEntity );
+					assertThat( mergedEntity.getId() ).isNotNull();
+					assertThat( newEntity.getId() ).isNull();
+				}
+		);
+	}
+
+
+	@Entity(name = "MyEntity")
+	public static class MyEntity {
+
+		@Id
+		@GeneratedValue
+		private Integer id;
+
+		private String name;
+
+		public Integer getId() {
+			return id;
+		}
+
+		public String getName() {
+			return name;
+		}
+	}
+
+}
+
+