HHH-16654 introduce a "default" fetch profile with eager to-ones in it

also, make the query translator always respect the fetch type specified
in the fetch profile (previously it would ignore it for statically-EAGER
many-to-ones, which was inconsistent and made little sense)

hibernate-core/src/main/java/org/hibernate/boot/model/internal/CollectionBinder.java

@@ -1463,7 +1463,6 @@ public abstract class CollectionBinder {
 					.addSecondPass( new FetchSecondPass( fetch, propertyHolder, propertyName, buildingContext ) );
 		}
 		else if ( property.isAnnotationPresent( FetchProfileOverrides.class ) ) {
-			boolean result = false;
 			for ( FetchProfileOverride fetch: property.getAnnotation( FetchProfileOverrides.class ).value() ) {
 				buildingContext.getMetadataCollector()
 						.addSecondPass( new FetchSecondPass( fetch, propertyHolder, propertyName, buildingContext ) );

hibernate-core/src/main/java/org/hibernate/boot/model/internal/DefaultFetchProfileOverride.java

@@ -0,0 +1,43 @@
+/*
+ * 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.boot.model.internal;
+
+import jakarta.persistence.FetchType;
+import org.hibernate.annotations.FetchProfileOverride;
+import org.hibernate.mapping.FetchProfile;
+
+import java.lang.annotation.Annotation;
+
+import static jakarta.persistence.FetchType.EAGER;
+
+/**
+ * @author Gavin King
+ */
+class DefaultFetchProfileOverride implements FetchProfileOverride {
+
+	static final FetchProfileOverride INSTANCE = new DefaultFetchProfileOverride();
+
+	@Override
+	public org.hibernate.annotations.FetchMode mode() {
+		return org.hibernate.annotations.FetchMode.JOIN;
+	}
+
+	@Override
+	public FetchType fetch() {
+		return EAGER;
+	}
+
+	@Override
+	public String profile() {
+		return FetchProfile.HIBERNATE_DEFAULT_PROFILE;
+	}
+
+	@Override
+	public Class<? extends Annotation> annotationType() {
+		return FetchProfileOverride.class;
+	}
+}

hibernate-core/src/main/java/org/hibernate/boot/model/internal/FetchSecondPass.java

@@ -17,6 +17,7 @@ import org.hibernate.mapping.FetchProfile;
 import org.hibernate.mapping.PersistentClass;
 
 import static org.hibernate.internal.util.StringHelper.qualify;
+import static org.hibernate.mapping.FetchProfile.HIBERNATE_DEFAULT_PROFILE;
 import static org.hibernate.mapping.MetadataSource.ANNOTATIONS;
 
 /**
@@ -42,19 +43,18 @@ public class FetchSecondPass implements SecondPass {
 	@Override
 	public void doSecondPass(Map<String, PersistentClass> persistentClasses) throws MappingException {
 
-		//TODO: handle propertyHolder.getPath() !!!!
-
-		// throws MappingException in case the property does not exist
-		buildingContext.getMetadataCollector()
-				.getEntityBinding( propertyHolder.getEntityName() )
-				.getProperty( propertyName );
-
 		FetchProfile profile = buildingContext.getMetadataCollector().getFetchProfile( fetch.profile() );
 		if ( profile == null ) {
-			throw new AnnotationException( "Property '" + qualify( propertyHolder.getPath(), propertyName )
+			if ( fetch.profile().equals( HIBERNATE_DEFAULT_PROFILE ) ) {
-					+ "' refers to an unknown fetch profile named '" + fetch.profile() + "'" );
+				profile = new FetchProfile( HIBERNATE_DEFAULT_PROFILE, ANNOTATIONS );
+				buildingContext.getMetadataCollector().addFetchProfile( profile );
+			}
+			else {
+				throw new AnnotationException( "Property '" + qualify( propertyHolder.getPath(), propertyName )
+						+ "' refers to an unknown fetch profile named '" + fetch.profile() + "'" );
+			}
 		}
-		else if ( profile.getSource() == ANNOTATIONS ) {
+		if ( profile.getSource() == ANNOTATIONS ) {
 			profile.addFetch(
 					new FetchProfile.Fetch(
 							propertyHolder.getEntityName(),

hibernate-core/src/main/java/org/hibernate/boot/model/internal/ToOneBinder.java

@@ -26,6 +26,7 @@ import org.hibernate.annotations.OnDeleteAction;
 import org.hibernate.annotations.common.reflection.XClass;
 import org.hibernate.annotations.common.reflection.XProperty;
 import org.hibernate.boot.spi.AccessType;
+import org.hibernate.boot.spi.InFlightMetadataCollector;
 import org.hibernate.boot.spi.MetadataBuildingContext;
 import org.hibernate.boot.spi.PropertyData;
 import org.hibernate.internal.CoreMessageLogger;
@@ -331,19 +332,34 @@ public class ToOneBinder {
 			XProperty property,
 			PropertyHolder propertyHolder,
 			PropertyData inferredData) {
+		final MetadataBuildingContext context = toOne.getBuildingContext();
+		final InFlightMetadataCollector collector = context.getMetadataCollector();
 		if ( property.isAnnotationPresent( FetchProfileOverride.class ) ) {
 			final FetchProfileOverride fetch = property.getAnnotation( FetchProfileOverride.class );
-			final MetadataBuildingContext context = toOne.getBuildingContext();
+			collector.addSecondPass( new FetchSecondPass( fetch, propertyHolder, inferredData.getPropertyName(), context ) );
-			context.getMetadataCollector()
-					.addSecondPass( new FetchSecondPass( fetch, propertyHolder, inferredData.getPropertyName(), context ) );
 		}
 		else if ( property.isAnnotationPresent( FetchProfileOverrides.class ) ) {
 			for ( FetchProfileOverride fetch: property.getAnnotation( FetchProfileOverrides.class ).value() ) {
-				final MetadataBuildingContext context = toOne.getBuildingContext();
+				collector.addSecondPass( new FetchSecondPass( fetch, propertyHolder, inferredData.getPropertyName(), context ) );
-				context.getMetadataCollector()
-						.addSecondPass( new FetchSecondPass( fetch, propertyHolder, inferredData.getPropertyName(), context ) );
 			}
 		}
+		if ( !toOne.isLazy()
+				&& !propertyHolder.isOrWithinEmbeddedId()
+				&& !propertyHolder.isWithinElementCollection()
+				&& !propertyHolder.isInIdClass()
+				// this is a bit of a problem: embeddable classes don't
+				// come with the entity name attached, so we can't
+				// create a Fetch that refers to their fields
+				&& !propertyHolder.isComponent()
+				// not sure exactly what the story is here:
+				&& !collector.isInSecondPass() ) {
+			collector.addSecondPass( new FetchSecondPass(
+					DefaultFetchProfileOverride.INSTANCE,
+					propertyHolder,
+					inferredData.getPropertyName(),
+					context
+			) );
+		}
 	}
 
 	private static void handleFetch(ToOne toOne, XProperty property) {

hibernate-core/src/main/java/org/hibernate/mapping/FetchProfile.java

@@ -22,6 +22,11 @@ import static jakarta.persistence.FetchType.EAGER;
  * @see org.hibernate.engine.profile.FetchProfile
  */
 public class FetchProfile {
+	/**
+	 * The name of an implicit fetch profile which includes all eager to-one associations.
+	 */
+	public static final String HIBERNATE_DEFAULT_PROFILE = "org.hibernate.defaultProfile";
+
 	private final String name;
 	private final MetadataSource source;
 	private final LinkedHashSet<Fetch> fetches = new LinkedHashSet<>();

hibernate-core/src/main/java/org/hibernate/query/sqm/sql/BaseSqmToSqlAstConverter.java

@@ -7636,7 +7636,7 @@ public abstract class BaseSqmToSqlAstConverter<T extends Statement> extends Base
 				}
 				else if ( getLoadQueryInfluencers().hasEnabledFetchProfiles() ) {
 					// There is no point in checking the fetch profile if it can't affect this fetchable
-					if ( fetchTiming != FetchTiming.IMMEDIATE || fetchable.incrementFetchDepth() ) {
+//					if ( fetchTiming != FetchTiming.IMMEDIATE || fetchable.incrementFetchDepth() ) {
 						final String fetchableRole = fetchable.getNavigableRole().getFullPath();
 
 						for ( String enabledFetchProfileName : getLoadQueryInfluencers()
@@ -7666,7 +7666,7 @@ public abstract class BaseSqmToSqlAstConverter<T extends Statement> extends Base
 									}
 								}
 							}
-						}
+//						}
 					}
 				}
 			}

hibernate-core/src/test/java/org/hibernate/orm/test/annotations/fetchprofile/NewFetchTest.java

@@ -24,7 +24,7 @@ import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 @SessionFactory
-@DomainModel(annotatedClasses = {NewFetchTest.class,NewFetchTest.E.class, NewFetchTest.F.class, NewFetchTest.G.class})
+@DomainModel(annotatedClasses = {NewFetchTest.class,NewFetchTest.E.class, NewFetchTest.F.class, NewFetchTest.G.class, NewFetchTest.H.class})
 @FetchProfile(name = NewFetchTest.NEW_PROFILE)
 @FetchProfile(name = NewFetchTest.OLD_PROFILE,
 		fetchOverrides = @FetchProfile.FetchOverride(entity = NewFetchTest.E.class, association = "f"))
@@ -160,6 +160,47 @@ public class NewFetchTest {
 		});
 	}
 
+	@Test void testDefaultProfile(SessionFactoryScope scope) {
+		scope.inTransaction( s-> {
+			G g = new G();
+			H h1 = new H();
+			h1.g = g;
+			H h2 = new H();
+			h2.g = g;
+			s.persist(g);
+			s.persist(h1);
+			s.persist(h2);
+		});
+		scope.getCollectingStatementInspector().assertExecutedCount(6);
+		scope.getCollectingStatementInspector().clear();
+
+		List<H> hs1 = scope.fromSession( s -> {
+			return s.createSelectionQuery("from H", H.class).getResultList();
+		});
+		assertTrue( isInitialized( hs1.get(0).g ) );
+		scope.getCollectingStatementInspector().assertExecutedCount(2);
+		scope.getCollectingStatementInspector().assertNumberOfJoins(0, 0);
+		scope.getCollectingStatementInspector().assertNumberOfJoins(1, 0);
+
+		scope.getCollectingStatementInspector().clear();
+		List<H> hs2 = scope.fromSession( s -> {
+			s.enableFetchProfile( org.hibernate.mapping.FetchProfile.HIBERNATE_DEFAULT_PROFILE );
+			return s.createSelectionQuery("from H", H.class).getResultList();
+		});
+		assertTrue( isInitialized( hs2.get(0).g ) );
+		scope.getCollectingStatementInspector().assertExecutedCount(1);
+		scope.getCollectingStatementInspector().assertNumberOfJoins(0,1);
+
+		scope.getCollectingStatementInspector().clear();
+		List<H> hs3 = scope.fromSession( s -> {
+			s.enableFetchProfile("test");
+			return s.createSelectionQuery("from H", H.class).getResultList();
+		});
+		assertTrue( isInitialized( hs3.get(0).g ) );
+		scope.getCollectingStatementInspector().assertExecutedCount(1);
+		scope.getCollectingStatementInspector().assertNumberOfJoins(0,1);
+	}
+
 	@Entity(name = "E")
 	static class E {
 		@Id @GeneratedValue
@@ -186,4 +227,13 @@ public class NewFetchTest {
 		@Id @GeneratedValue
 		Long id;
 	}
+
+	@FetchProfile(name = "test")
+	@Entity(name = "H")
+	static class H {
+		@Id @GeneratedValue
+		Long id;
+		@FetchProfileOverride(profile = "test", mode = JOIN)
+		@ManyToOne G g;
+	}
 }