fixed source of NPE wrt accessing an entity's version attribute descriptor when no versioning is defined;

added `@org.hibernate.testing.orm.junit.SessionFactory#exportSchema`

hibernate-core/src/main/java/org/hibernate/persister/entity/AbstractEntityPersister.java

@@ -141,10 +141,10 @@ import org.hibernate.metamodel.mapping.ModelPart;
 import org.hibernate.metamodel.mapping.NaturalIdMapping;
 import org.hibernate.metamodel.mapping.Queryable;
 import org.hibernate.metamodel.mapping.StateArrayContributorMapping;
+import org.hibernate.metamodel.mapping.StateArrayContributorMetadata;
 import org.hibernate.metamodel.mapping.internal.InFlightEntityMappingType;
 import org.hibernate.metamodel.mapping.internal.MappingModelCreationHelper;
 import org.hibernate.metamodel.mapping.internal.MappingModelCreationProcess;
-import org.hibernate.metamodel.model.domain.EntityDomainType;
 import org.hibernate.metamodel.model.domain.NavigableRole;
 import org.hibernate.metamodel.spi.EntityRepresentationStrategy;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
@@ -159,10 +159,7 @@ import org.hibernate.property.access.spi.PropertyAccess;
 import org.hibernate.property.access.spi.Setter;
 import org.hibernate.query.ComparisonOperator;
 import org.hibernate.query.NavigablePath;
-import org.hibernate.query.sqm.SqmPathSource;
-import org.hibernate.query.sqm.sql.SqlAstCreationState;
 import org.hibernate.query.sqm.sql.SqlExpressionResolver;
-import org.hibernate.query.sqm.tree.domain.SqmPath;
 import org.hibernate.sql.Alias;
 import org.hibernate.sql.Delete;
 import org.hibernate.sql.Insert;
@@ -174,7 +171,6 @@ import org.hibernate.sql.SimpleSelect;
 import org.hibernate.sql.Template;
 import org.hibernate.sql.Update;
 import org.hibernate.sql.ast.Clause;
-import org.hibernate.sql.ast.spi.FromClauseAccess;
 import org.hibernate.sql.ast.spi.SqlAliasBase;
 import org.hibernate.sql.ast.spi.SqlAliasBaseGenerator;
 import org.hibernate.sql.ast.spi.SqlAliasStemHelper;
@@ -5357,7 +5353,12 @@ public abstract class AbstractEntityPersister
 
 	@Override
 	public Object getVersion(Object object) {
-		return getVersionMapping().getAttributeMetadataAccess().resolveAttributeMetadata( this ).getPropertyAccess().getGetter().get( object );
+		if ( getVersionMapping() == null ) {
+			return null;
+		}
+		final StateArrayContributorMetadata attrMetadata = getVersionMapping().getAttributeMetadataAccess().resolveAttributeMetadata( this );
+		assert attrMetadata != null;
+		return attrMetadata.getPropertyAccess().getGetter().get( object );
 	}
 
 	@Override

hibernate-core/src/test/java/org/hibernate/orm/test/loading/LoadingSmokeTests.java

@@ -0,0 +1,87 @@
+/*
+ * 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.loading;
+
+import org.hibernate.Hibernate;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.query.spi.QueryImplementor;
+
+import org.hibernate.testing.junit4.BaseNonConfigCoreFunctionalTestCase;
+import org.hibernate.testing.orm.domain.StandardDomainModel;
+import org.hibernate.testing.orm.domain.gambit.BasicEntity;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.FailureExpected;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryFunctionalTesting;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import org.hamcrest.MatcherAssert;
+
+import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * @author Steve Ebersole
+ */
+@DomainModel(
+		standardModels = StandardDomainModel.GAMBIT
+)
+@SessionFactory
+@SessionFactoryFunctionalTesting
+@SuppressWarnings("WeakerAccess")
+public class LoadingSmokeTests {
+	@Test
+	public void testBasicLoad(SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					final BasicEntity loaded = session.byId( BasicEntity.class ).getReference( 1 );
+					assertThat( loaded, notNullValue() );
+					assertFalse( Hibernate.isInitialized( loaded ) );
+				}
+		);
+	}
+
+	@Test
+	@FailureExpected( reason = "read-by-position not yet implemented for loading" )
+	public void testBasicGet(SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					final BasicEntity gotten = session.byId( BasicEntity.class ).load( 1 );
+					assertThat( gotten, notNullValue() );
+					assertTrue( Hibernate.isInitialized( gotten ) );
+				}
+		);
+	}
+
+	@BeforeAll
+	public void createTestData(SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					session.persist( new BasicEntity( 1, "first" ) );
+					session.persist( new BasicEntity( 2, "second" ) );
+				}
+		);
+	}
+
+	@AfterAll
+	public void deleteTestData(SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					session.doWork(
+							connection -> {
+								connection.prepareStatement( "delete from BasicEntity" ).execute();
+							}
+					);
+				}
+		);
+	}
+}

hibernate-testing/src/main/java/org/hibernate/testing/orm/junit/DomainModelExtension.java

@@ -32,7 +32,7 @@ public class DomainModelExtension
 		return JUnitHelper.locateExtensionStore( ServiceRegistryExtension.class, context, testInstance );
 	}
 
-	public static DomainModelScope findMetamodelScope(Object testInstance, ExtensionContext context) {
+	public static DomainModelScope findDomainModelScope(Object testInstance, ExtensionContext context) {
 		final ExtensionContext.Store store = locateExtensionStore( testInstance, context );
 		final DomainModelScope existing = (DomainModelScope) store.get( MODEL_KEY );
 		if ( existing != null ) {
@@ -120,7 +120,7 @@ public class DomainModelExtension
 
 	@Override
 	public void postProcessTestInstance(Object testInstance, ExtensionContext context) {
-		findMetamodelScope( testInstance, context );
+		findDomainModelScope( testInstance, context );
 	}
 
 	@Override

hibernate-testing/src/main/java/org/hibernate/testing/orm/junit/DomainModelParameterResolver.java

@@ -28,7 +28,7 @@ public class DomainModelParameterResolver implements ParameterResolver {
 	public Object resolveParameter(
 			ParameterContext parameterContext,
 			ExtensionContext extensionContext) throws ParameterResolutionException {
-		final DomainModelScope modelScope = DomainModelExtension.findMetamodelScope(
+		final DomainModelScope modelScope = DomainModelExtension.findDomainModelScope(
 				extensionContext.getRequiredTestInstance(),
 				extensionContext
 		);

hibernate-testing/src/main/java/org/hibernate/testing/orm/junit/SessionFactory.java

@@ -42,6 +42,7 @@ public @interface SessionFactory {
 	String sessionFactoryName() default "";
 
 	boolean generateStatistics() default false;
+	boolean exportSchema() default true;
 
 	Class<? extends Interceptor> interceptorClass() default Interceptor.class;
 

hibernate-testing/src/main/java/org/hibernate/testing/orm/junit/SessionFactoryExtension.java

@@ -6,17 +6,26 @@
  */
 package org.hibernate.testing.orm.junit;
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
 import org.hibernate.Interceptor;
+import org.hibernate.SessionFactoryObserver;
 import org.hibernate.Transaction;
 import org.hibernate.boot.SessionFactoryBuilder;
+import org.hibernate.boot.registry.StandardServiceRegistry;
+import org.hibernate.boot.spi.MetadataImplementor;
+import org.hibernate.cfg.AvailableSettings;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SessionImplementor;
 import org.hibernate.internal.util.StringHelper;
 import org.hibernate.resource.jdbc.spi.StatementInspector;
+import org.hibernate.tool.schema.Action;
+import org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator;
+import org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.ActionGrouping;
 
 import org.junit.jupiter.api.extension.AfterAllCallback;
 import org.junit.jupiter.api.extension.ExtensionContext;
@@ -49,6 +58,8 @@ public class SessionFactoryExtension
 
 		SessionFactoryProducer producer = null;
 
+		final DomainModelScope domainModelScope = DomainModelExtension.findDomainModelScope( testInstance, context );
+
 		if ( testInstance instanceof SessionFactoryProducer ) {
 			producer = (SessionFactoryProducer) testInstance;
 		}
@@ -85,7 +96,13 @@ public class SessionFactoryExtension
 							);
 						}
 
-						return (SessionFactoryImplementor) sessionFactoryBuilder.build();
+						final SessionFactoryImplementor sessionFactory = (SessionFactoryImplementor) sessionFactoryBuilder.build();
+
+						if ( sessionFactoryConfig.exportSchema() ) {
+							prepareSchemaExport( sessionFactory, model );
+						}
+
+						return sessionFactory;
 					}
 					catch (Exception e) {
 						throw new RuntimeException( "Could not build SessionFactory", e );
@@ -98,9 +115,8 @@ public class SessionFactoryExtension
 			throw new IllegalStateException( "Could not determine SessionFactory producer" );
 		}
 
-
 		final SessionFactoryScopeImpl sfScope = new SessionFactoryScopeImpl(
-				DomainModelExtension.findMetamodelScope( testInstance, context ),
+				domainModelScope,
 				producer
 		);
 
@@ -113,6 +129,40 @@ public class SessionFactoryExtension
 		return sfScope;
 	}
 
+	private static void prepareSchemaExport(
+			SessionFactoryImplementor sessionFactory,
+			MetadataImplementor model) {
+		final Map<String, Object> baseProperties = sessionFactory.getProperties();
+
+		final ActionGrouping actions = ActionGrouping.interpret( baseProperties );
+
+		// if there are explicit setting for auto schema tooling then skip the annotation
+		if ( actions.getDatabaseAction() != Action.NONE || actions.getScriptAction() != Action.NONE ) {
+			// the properties contained explicit settings for auto schema tooling - skip the annotation
+			return;
+		}
+
+		final HashMap settings = new HashMap<>( baseProperties );
+		//noinspection unchecked
+		settings.put( AvailableSettings.HBM2DDL_DATABASE_ACTION, Action.CREATE_DROP );
+
+		final StandardServiceRegistry serviceRegistry = model.getMetadataBuildingOptions().getServiceRegistry();
+
+		SchemaManagementToolCoordinator.process(
+				model,
+				serviceRegistry,
+				settings,
+				action -> sessionFactory.addObserver(
+						new SessionFactoryObserver() {
+							@Override
+							public void sessionFactoryClosing(org.hibernate.SessionFactory factory) {
+								action.perform( serviceRegistry );
+							}
+						}
+				)
+		);
+	}
+
 	@Override
 	public void postProcessTestInstance(Object testInstance, ExtensionContext context) {
 		log.tracef( "#postProcessTestInstance(%s, %s)", testInstance, context.getDisplayName() );