HHH-13655 Fix NullPointerException for audited MapKeyEnumerated collections with basic value types

hibernate-envers/src/main/java/org/hibernate/envers/configuration/internal/ClassesAuditingData.java

@@ -115,8 +115,12 @@ public class ClassesAuditingData {
 
 		if ( propertyAuditingData.getMapKeyEnumType() != null ) {
 			final String referencedEntityName = MappingTools.getReferencedEntityName( property.getValue() );
-			final ClassAuditingData referencedAuditingData = entityNameToAuditingData.get( referencedEntityName );
+			if ( referencedEntityName != null ) {
-			addMapEnumeratedKey( property.getValue(), property.getPropertyAccessorName(), referencedAuditingData );
+				// If no entity could be determined, this means the enum type isn't an entity mapping and instead is one
+				// to a basic type.  In this use case, there is nothing special to do.
+				final ClassAuditingData referencedAuditingData = entityNameToAuditingData.get( referencedEntityName );
+				addMapEnumeratedKey( property.getValue(), property.getPropertyAccessorName(), referencedAuditingData );
+			}
 		}
 
 		// HHH-9108

hibernate-envers/src/main/java/org/hibernate/envers/configuration/internal/metadata/CollectionMetadataGenerator.java

@@ -526,8 +526,9 @@ public final class CollectionMetadataGenerator {
 			final IndexedCollection indexedValue = (IndexedCollection) propertyValue;
 			final String mapKey = propertyAuditingData.getMapKey();
 			final EnumType mapKeyEnumType = propertyAuditingData.getMapKeyEnumType();
-			if ( mapKey == null && mapKeyEnumType == null ) {
+			if ( ( mapKey == null && mapKeyEnumType == null ) || ( mapKeyEnumType != null && referencedEntityName == null ) ) {
-				// This entity doesn't specify a javax.persistence.MapKey. Mapping it to the middle entity.
+				// This entity doesn't specify a javax.persistence.MapKey or there is a MapKeyEnumerated but its a non-entity type.
+				// Mapping it to the middle entity.
 				return addValueToMiddleTable(
 						indexedValue.getIndex(),
 						middleEntityXml,

hibernate-envers/src/test/java/org/hibernate/envers/test/integration/collection/mapkey/MapKeyEnumeratedNonEntityTest.java

@@ -0,0 +1,156 @@
+/*
+ * 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.envers.test.integration.collection.mapkey;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.persistence.CollectionTable;
+import javax.persistence.ElementCollection;
+import javax.persistence.Entity;
+import javax.persistence.EnumType;
+import javax.persistence.Id;
+import javax.persistence.MapKeyColumn;
+import javax.persistence.MapKeyEnumerated;
+
+import org.hibernate.envers.Audited;
+import org.hibernate.envers.test.BaseEnversJPAFunctionalTestCase;
+import org.hibernate.envers.test.Priority;
+import org.hibernate.envers.test.tools.TestTools;
+import org.junit.Test;
+
+import org.hibernate.testing.TestForIssue;
+
+import static org.hibernate.envers.test.tools.TestTools.checkCollection;
+import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Chris Cranford
+ */
+@TestForIssue(jiraKey = "HHH-13655")
+public class MapKeyEnumeratedNonEntityTest extends BaseEnversJPAFunctionalTestCase {
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class<?>[] { TestEntity.class };
+	}
+
+	@Test
+	@Priority(10)
+	public void initData() {
+		// Revision 1
+		doInJPA( this::entityManagerFactory, entityManager -> {
+
+			final TestEntity test = new TestEntity();
+			test.setId( 1 );
+			test.addMapKeyAssociation( TestEnum.ONE, 1 );
+
+			entityManager.persist( test );
+		} );
+
+		// Revision 2
+		doInJPA( this::entityManagerFactory, entityManager -> {
+			final TestEntity test = entityManager.find( TestEntity.class, 1 );
+			test.addMapKeyAssociation( TestEnum.TWO, 2 );
+
+			entityManager.merge( test );
+		} );
+
+		// Revision 3
+		doInJPA( this::entityManagerFactory, entityManager -> {
+			final TestEntity test = entityManager.find( TestEntity.class, 1 );
+			test.removeMapKeyAssociation( TestEnum.ONE );
+			entityManager.merge( test );
+		} );
+
+		// Revision 4
+		doInJPA( this::entityManagerFactory, entityManager -> {
+			final TestEntity test = entityManager.find( TestEntity.class, 1 );
+			test.removeMapKeyAssociation( TestEnum.TWO );
+			entityManager.merge( test );
+		} );
+	}
+
+	@Test
+	public void testRevisionNumberHistory() {
+		assertEquals( Arrays.asList( 1, 2, 3, 4 ), getAuditReader().getRevisions( TestEntity.class, 1 ) );
+	}
+
+	@Test
+	public void testRevisionHistory() {
+
+		final TestEntity rev1 = getAuditReader().find( TestEntity.class, 1, 1 );
+		assertEquals( 1, rev1.getMapEnumMap().size() );
+		assertEquals( TestEnum.ONE, rev1.getMapEnumMap().keySet().iterator().next() );
+
+		final TestEntity rev2 = getAuditReader().find( TestEntity.class, 1, 2 );
+		assertEquals( 2, rev2.getMapEnumMap().size() );
+		assertEquals( TestTools.makeSet( TestEnum.ONE, TestEnum.TWO ), rev2.getMapEnumMap().keySet() );
+		checkCollection( rev2.getMapEnumMap().values(), 1, 2 );
+
+		final TestEntity rev3 = getAuditReader().find( TestEntity.class, 1, 3 );
+		assertEquals( 1, rev3.getMapEnumMap().size() );
+		assertEquals( TestTools.makeSet( TestEnum.TWO ), rev3.getMapEnumMap().keySet() );
+		checkCollection( rev2.getMapEnumMap().values(), 2 );
+
+		final TestEntity rev4 = getAuditReader().find( TestEntity.class, 1, 4 );
+		assertEquals( 0, rev4.getMapEnumMap().size() );
+	}
+
+	public enum TestEnum {
+		ONE,
+		TWO
+	}
+
+	@Entity(name = "TestEntity")
+	@Audited
+	public static class TestEntity {
+		@Id
+		private Integer id;
+
+		@MapKeyEnumerated(EnumType.STRING)
+		@ElementCollection
+		@CollectionTable(name = "test_Entity_enum_items")
+		@MapKeyColumn(name = "type", length = 20, nullable = false)
+		private Map<TestEnum, Integer> mapEnumMap = new HashMap<>();
+
+		public Integer getId() {
+			return id;
+		}
+
+		public void setId(Integer id) {
+			this.id = id;
+		}
+
+		public Map<TestEnum, Integer> getMapEnumMap() {
+			return mapEnumMap;
+		}
+
+		public void setMapEnumMap(Map<TestEnum, Integer> mapEnumMap) {
+			this.mapEnumMap = mapEnumMap;
+		}
+
+		@Override
+		public String toString() {
+			return "TestEntity{" +
+					"id=" + id +
+					", mapEnumMap=" + mapEnumMap +
+					'}';
+		}
+
+		public void addMapKeyAssociation(TestEnum key, Integer value) {
+			mapEnumMap.put( key, value );
+		}
+
+		public Integer removeMapKeyAssociation(TestEnum key) {
+			final Integer value = mapEnumMap.get( key );
+			mapEnumMap.remove( key );
+			return value;
+		}
+	}
+}