HHH-17383 Association is null in lazy initialized element collection

hibernate-core/src/main/java/org/hibernate/sql/results/graph/embeddable/AbstractEmbeddableInitializer.java

@@ -8,6 +8,7 @@
 
 import org.hibernate.engine.internal.ManagedTypeHelper;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
+import org.hibernate.metamodel.mapping.CollectionPart;
 import org.hibernate.metamodel.mapping.CompositeIdentifierMapping;
 import org.hibernate.metamodel.mapping.EmbeddableMappingType;
 import org.hibernate.metamodel.mapping.EmbeddableValuedModelPart;
@@ -123,7 +124,7 @@ public Object getCompositeInstance() {
 
 	@Override
 	public FetchParentAccess findFirstEntityDescriptorAccess() {
-		if ( fetchParentAccess == null ) {
+		if ( fetchParentAccess == null || embedded instanceof CollectionPart ) {
 			return null;
 		}
 		return fetchParentAccess.findFirstEntityDescriptorAccess();

hibernate-core/src/test/java/org/hibernate/orm/test/embeddable/ElementCollectionLazyToOneTest.java

@@ -0,0 +1,137 @@
+package org.hibernate.orm.test.embeddable;
+
+import java.util.List;
+
+import org.hibernate.jpa.SpecHints;
+
+import org.hibernate.testing.orm.junit.EntityManagerFactoryScope;
+import org.hibernate.testing.orm.junit.JiraKey;
+import org.hibernate.testing.orm.junit.Jpa;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.ElementCollection;
+import jakarta.persistence.Embeddable;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.TypedQuery;
+import jakarta.persistence.criteria.CriteriaBuilder;
+import jakarta.persistence.criteria.CriteriaQuery;
+import jakarta.persistence.criteria.Root;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+@Jpa(
+		annotatedClasses = {
+				ElementCollectionLazyToOneTest.TheEntity.class
+		}
+)
+@JiraKey( "HHH-17383" )
+public class ElementCollectionLazyToOneTest {
+
+	private static final Long ENTITY_1 = 1L;
+	private static final Long ENTITY_2 = 2L;
+
+	@BeforeAll
+	public void setUp(EntityManagerFactoryScope scope) {
+		scope.inTransaction(
+				entityManager -> {
+					TheEntity e2 = new TheEntity( ENTITY_2, "e2" );
+					TheEntity e1 = new TheEntity( ENTITY_1, "e1" );
+					TheEmbeddable embeddable = new TheEmbeddable();
+					embeddable.setContent( "abc" );
+					embeddable.setEntity( e2 );
+					e1.setEmbeddables( List.of( embeddable ) );
+					entityManager.persist( e2 );
+					entityManager.persist( e1 );
+				}
+		);
+	}
+
+	@Test
+	public void testInitializingCollection(EntityManagerFactoryScope scope) {
+		scope.inTransaction(
+				entityManager -> {
+					TheEntity entity = entityManager.find( TheEntity.class, ENTITY_1 );
+					entityManager.createQuery( "from TheEntity e left join fetch e.embeddables" ).getResultList();
+
+					List<TheEmbeddable> embeddables = entity.getEmbeddables();
+					assertThat( embeddables.size() ).isEqualTo( 1 );
+					TheEmbeddable theEmbeddable = embeddables.get( 0 );
+					assertNotNull( theEmbeddable );
+					assertThat( theEmbeddable.getEntity() ).isNotNull();
+				}
+		);
+	}
+
+	@Embeddable
+	public static class TheEmbeddable {
+		@Column
+		private String content;
+		@ManyToOne(fetch = FetchType.LAZY)
+		private TheEntity entity;
+
+		public String getContent() {
+			return content;
+		}
+
+		public void setContent(String content) {
+			this.content = content;
+		}
+
+		public TheEntity getEntity() {
+			return entity;
+		}
+
+		public void setEntity(TheEntity entity) {
+			this.entity = entity;
+		}
+	}
+
+	@Entity(name = "TheEntity")
+	public static class TheEntity {
+		@Id
+		private Long id;
+		private String name;
+
+		@ElementCollection
+		private List<TheEmbeddable> embeddables;
+
+		public TheEntity() {
+		}
+
+		public TheEntity(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<TheEmbeddable> getEmbeddables() {
+			return embeddables;
+		}
+
+		public void setEmbeddables(List<TheEmbeddable> embeddables) {
+			this.embeddables = embeddables;
+		}
+	}
+
+}