HHH-7180 Test and fix collection key comparison in ProxyVisitor

Author: beikov

hibernate-core/src/main/java/org/hibernate/event/internal/ProxyVisitor.java

@@ -39,7 +39,7 @@ protected static boolean isOwnerUnchanged(
 			CollectionPersister persister, Object id, PersistentCollection<?> snapshot) {
 		return isCollectionSnapshotValid( snapshot )
 			&& persister.getRole().equals( snapshot.getRole() )
-			&& id.equals( snapshot.getKey() );
+			&& persister.getKeyType().isEqual( id, snapshot.getKey() );
 	}
 
 	private static boolean isCollectionSnapshotValid(PersistentCollection<?> snapshot) {

hibernate-core/src/test/java/org/hibernate/orm/test/id/array/PrimitiveByteArrayIdCollectionTest.java

@@ -0,0 +1,132 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.id.array;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import org.hibernate.community.dialect.InformixDialect;
+import org.hibernate.dialect.MySQLDialect;
+import org.hibernate.dialect.OracleDialect;
+import org.hibernate.stat.spi.StatisticsImplementor;
+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.hibernate.testing.orm.junit.SkipForDialect;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+
+@SkipForDialect(dialectClass = MySQLDialect.class, majorVersion = 5, reason = "BLOB/TEXT column 'id' used in key specification without a key length")
+@SkipForDialect(dialectClass = OracleDialect.class, matchSubTypes = true, reason = "ORA-02329: column of datatype LOB cannot be unique or a primary key")
+@SkipForDialect(dialectClass = InformixDialect.class, reason = "Informix does not support unique / primary constraints on binary columns")
+@DomainModel(
+		annotatedClasses = {
+				PrimitiveByteArrayIdCollectionTest.Parent.class,
+				PrimitiveByteArrayIdCollectionTest.Child.class
+		}
+)
+@SessionFactory
+public class PrimitiveByteArrayIdCollectionTest {
+
+	@BeforeEach
+	public void prepare(SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					Parent entity = new Parent();
+					entity.id = new byte[] {
+							(byte) ( 1 ),
+							(byte) ( 2 ),
+							(byte) ( 3 ),
+							(byte) ( 4 )
+					};
+					entity.name = "Simple name";
+
+					for ( int j = 1; j <= 2; j++ ) {
+						Child child = new Child();
+						child.id = j;
+						entity.name = "Child name " + j;
+						child.parent = entity;
+						entity.children.add(child);
+					}
+					session.persist( entity );
+				}
+		);
+	}
+
+	@AfterEach
+	public void cleanup(SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					session.createQuery( "delete from Child" ).executeUpdate();
+					session.createQuery( "delete from Parent" ).executeUpdate();
+				}
+		);
+	}
+
+	@Test
+	@JiraKey(value = "HHH-7180")
+	public void testReattach(SessionFactoryScope scope) {
+		// Since reattachment was removed in ORM 7,
+		// but the code path to trigger the bug is still reachable through removing a detached entity,
+		// construct a scenario that shows a problem
+
+		final Parent parent = scope.fromTransaction(
+				session -> session.createQuery( "from Parent p", Parent.class ).getSingleResult()
+		);
+		// Copy the byte-array id which will make it a different instance, yet equal to the collection key
+		parent.id = parent.id.clone();
+
+		final StatisticsImplementor statistics = scope.getSessionFactory().getStatistics();
+		statistics.setStatisticsEnabled( true );
+		statistics.clear();
+
+		scope.inTransaction(
+				session -> {
+					session.remove( parent );
+					session.flush();
+
+					// The collection will be removed twice if the collection key can't be matched to the entity id
+					assertEquals( 1L, statistics.getCollectionRemoveCount() );
+				}
+		);
+
+	}
+
+	@Entity(name = "Parent")
+	public static class Parent {
+		@Id
+		public byte[] id;
+		public String name;
+		@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
+		public Set<Child> children = new HashSet<>();
+	}
+
+	@Entity(name = "Child")
+	public static class Child {
+		@Id
+		public Integer id;
+		public String name;
+		@ManyToOne(fetch = FetchType.LAZY)
+		public Parent parent;
+
+		public Child() {
+		}
+
+		public Child(Integer id) {
+			this.id = id;
+		}
+	}
+}