HHH-14078 Avoid duplicate elements when initializing bag with queued operations

hibernate-core/src/main/java/org/hibernate/collection/spi/PersistentBag.java

@@ -635,7 +635,15 @@ public class PersistentBag<E> extends AbstractPersistentCollection<E> implements
 
 		@Override
 		public void operate() {
-			bag.add( getAddedInstance() );
+			// Delayed operations only work on inverse collections i.e. collections with mappedBy,
+			// and these collections don't have duplicates by definition.
+			// Since cascading also operates on delayed operation's elements,
+			// it can happen that an element is already associated with the collection after cascading,
+			// but the queued operations are still executed after the lazy initialization of the collection.
+			// To avoid duplicates, we have to check if the bag already contains this element
+			if ( !bag.contains( getAddedInstance() ) ) {
+				bag.add( getAddedInstance() );
+			}
 		}
 	}
 

hibernate-core/src/test/java/org/hibernate/orm/test/onetomany/OneToManyDuplicatesTest.java

@@ -0,0 +1,173 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+package org.hibernate.orm.test.onetomany;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.hibernate.testing.orm.junit.DialectFeatureChecks;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.JiraKey;
+import org.hibernate.testing.orm.junit.RequiresDialectFeature;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@SessionFactory
+@DomainModel(annotatedClasses = {
+		OneToManyDuplicatesTest.UserContact.class,
+		OneToManyDuplicatesTest.ContactInfo.class
+})
+@RequiresDialectFeature(feature = DialectFeatureChecks.SupportsIdentityColumns.class)
+@JiraKey( "HHH-14078" )
+public class OneToManyDuplicatesTest {
+
+	@AfterAll
+	public void tearDown(SessionFactoryScope scope) {
+		scope.inTransaction( session -> {
+			session.createMutationQuery( "delete from ContactInfo" ).executeUpdate();
+			session.createMutationQuery( "delete from UserContact" ).executeUpdate();
+		} );
+	}
+
+	@Test
+	public void test(SessionFactoryScope scope) {
+		Long kevinId = scope.fromTransaction( session -> {
+			UserContact userContact = new UserContact();
+			userContact.setName( "Kevin" );
+			session.persist( userContact );
+			return userContact.getId();
+		} );
+		scope.inTransaction( session -> {
+			UserContact userContact = session.find( UserContact.class, kevinId );
+			ContactInfo contactInfo = new ContactInfo();
+			contactInfo.setPhoneNumber( "123" );
+
+			contactInfo.setUserContact( userContact );
+			userContact.getContactInfos().add( contactInfo );
+			session.merge( userContact );
+
+			assertEquals( 1, userContact.getContactInfos().size() );
+		} );
+
+		scope.inTransaction( session -> {
+			UserContact userContact = session.find( UserContact.class, 1L );
+			assertEquals( 1, userContact.getContactInfos().size() );
+		});
+	}
+
+	@Entity(name = "UserContact")
+	public static class UserContact {
+		@Id
+		@GeneratedValue(strategy = GenerationType.IDENTITY)
+		private Long id;
+
+		private String name;
+
+		@OneToMany(cascade = CascadeType.ALL, mappedBy = "userContact")
+		private List<ContactInfo> contactInfos = new ArrayList<>();
+
+		public UserContact() {
+		}
+
+		public UserContact(Long id, String name) {
+			this.id = id;
+			this.name = name;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		public void setId(Long id) {
+			this.id = id;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+		public List<ContactInfo> getContactInfos() {
+			return contactInfos;
+		}
+
+		public void setContactInfos(List<ContactInfo> contactInfos) {
+			this.contactInfos = contactInfos;
+		}
+	}
+
+	@Entity(name = "ContactInfo")
+	public static class ContactInfo {
+		@Id
+		@GeneratedValue(strategy = GenerationType.IDENTITY)
+		private Long id;
+
+		private String phoneNumber;
+
+		private String address;
+
+		@ManyToOne
+		private UserContact userContact;
+
+		public ContactInfo() {
+		}
+
+		public ContactInfo(Long id, String phoneNumber, String address, UserContact userContact) {
+			this.id = id;
+			this.phoneNumber = phoneNumber;
+			this.address = address;
+			this.userContact = userContact;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		public void setId(Long id) {
+			this.id = id;
+		}
+
+		public String getPhoneNumber() {
+			return phoneNumber;
+		}
+
+		public void setPhoneNumber(String phoneNumber) {
+			this.phoneNumber = phoneNumber;
+		}
+
+		public String getAddress() {
+			return address;
+		}
+
+		public void setAddress(String address) {
+			this.address = address;
+		}
+
+		public UserContact getUserContact() {
+			return userContact;
+		}
+
+		public void setUserContact(UserContact userContact) {
+			this.userContact = userContact;
+		}
+	}
+}