HHH-18871 allow collections to be mapped correctly while determining navigation path

hibernate-core/src/main/java/org/hibernate/query/sql/internal/ResultSetMappingProcessor.java

@@ -16,6 +16,7 @@
 import org.hibernate.LockMode;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.loader.internal.AliasConstantsHelper;
+import org.hibernate.metamodel.mapping.CollectionPart;
 import org.hibernate.metamodel.mapping.EntityMappingType;
 import org.hibernate.metamodel.mapping.PluralAttributeMapping;
 import org.hibernate.metamodel.mapping.internal.ToOneAttributeMapping;
@@ -260,16 +261,19 @@ private List<String> columnNames(
 
 	private NavigablePath determineNavigablePath(LegacyFetchBuilder fetchBuilder) {
 		final var ownerResult = alias2Return.get( fetchBuilder.getOwnerAlias() );
-		final NavigablePath path;
+		final NavigablePath basePath;
 		if ( ownerResult instanceof NativeQuery.RootReturn rootReturn ) {
-			path = rootReturn.getNavigablePath();
+			basePath = rootReturn.getNavigablePath();
 		}
 		else if ( ownerResult instanceof DynamicFetchBuilderLegacy dynamicFetchBuilderLegacy ) {
-			path = determineNavigablePath( dynamicFetchBuilderLegacy );
+			basePath = determineNavigablePath( dynamicFetchBuilderLegacy );
 		}
 		else {
 			throw new AssertionFailure( "Unexpected fetch builder" );
 		}
+		final NavigablePath path = alias2CollectionPersister.containsKey( fetchBuilder.getOwnerAlias() )
+				? basePath.append( CollectionPart.Nature.ELEMENT.getName() )
+				: basePath;
 		return path.append( fetchBuilder.getFetchable().getFetchableName() );
 	}
 

hibernate-core/src/test/java/org/hibernate/orm/test/query/NativeQueryNestedTreeTest.java

@@ -0,0 +1,108 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.query;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.Jira;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.Test;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
+/**
+ * This reproduces an issue in Hibernate 6 parsing native queries.
+ */
+@DomainModel(
+		annotatedClasses = {
+				NativeQueryNestedTreeTest.Tree.class,
+				NativeQueryNestedTreeTest.Forest.class
+		}
+)
+@SessionFactory
+@Jira("https://hibernate.atlassian.net/browse/HHH-18871")
+public class NativeQueryNestedTreeTest {
+
+	@Test
+	public void test(SessionFactoryScope scope) {
+		// We want to make sure 'Could not locate TableGroup' no longer is thrown
+		assertDoesNotThrow( () -> scope.inTransaction( session ->
+				session.createNativeQuery( """
+								select {t.*}, {t2.*}, {t3.*}
+								from tree t
+								inner join tree t2 on t2.parent_id = t.id
+								inner join tree t3 on t3.parent_id = t2.id
+								""", Tree.class )
+						.addEntity( "t", Tree.class )
+						.addJoin( "t2", "t.children" )
+						.addJoin( "t3", "t2.children" )
+						.list()
+		) );
+
+		assertDoesNotThrow( () -> scope.inTransaction( session ->
+				session.createNativeQuery( """
+								select {t.*}, {t2.*}, {t3.*}, {t4.*}
+								from tree t
+								inner join tree t2 on t2.parent_id = t.id
+								inner join tree t3 on t3.parent_id = t2.id
+								inner join tree t4 on t4.parent_id = t3.id
+								""", Tree.class )
+						.addEntity( "t", Tree.class )
+						.addJoin( "t2", "t.children" )
+						.addJoin( "t3", "t2.children" )
+						.addJoin( "t4", "t3.children" )
+						.list()
+		) );
+
+		assertDoesNotThrow( () -> scope.inTransaction( session ->
+				session.createNativeQuery( """
+								select {f.*}, {t.*}, {t2.*}
+								from forest f
+								inner join tree t on t.parent_id is null
+								inner join tree t2 on t2.parent_id = t.id
+								""", Forest.class )
+						.addEntity( "f", Forest.class )
+						.addJoin( "t", "f.trees" )
+						.addJoin( "t2", "t.children" )
+						.list()
+		) );
+	}
+
+	@Entity(name = "Tree")
+	@Table(name = "tree")
+	public static class Tree {
+		@ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
+		@JoinColumn(name = "parent_id")
+		private Tree parent;
+		@OneToMany(mappedBy = "parent", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
+		private Set<Tree> children = new HashSet<>();
+		@Id
+		@GeneratedValue
+		private long id;
+	}
+
+	@Entity(name = "Forest")
+	@Table(name = "forest")
+	public static class Forest {
+		@Id
+		@GeneratedValue
+		private Long id;
+		@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
+		@JoinColumn(name = "forest_id")
+		private Set<Tree> trees = new HashSet<>();
+	}
+}