HHH-19868 RowTransformerConstructorImpl throws NullPointerException when TupleMetadata is null

Author: dreab8

hibernate-core/src/main/java/org/hibernate/query/sqm/internal/AbstractSqmSelectionQuery.java

@@ -316,7 +316,7 @@ protected TupleMetadata buildTupleMetadata(SqmStatement<?> statement, Class<R> r
 		if ( statement instanceof SqmSelectStatement<?> select ) {
 			final var selections =
 					select.getQueryPart().getFirstQuerySpec().getSelectClause().getSelections();
-			return isTupleMetadataRequired( resultType, selections.get(0) )
+			return selections.size() > 1 || isTupleMetadataRequired( resultType, selections.get(0) )
 					? getTupleMetadata( selections )
 					: null;
 		}

hibernate-core/src/main/java/org/hibernate/sql/results/internal/RowTransformerConstructorImpl.java

@@ -6,6 +6,7 @@
 
 import jakarta.persistence.TupleElement;
 import org.hibernate.InstantiationException;
+import org.hibernate.query.QueryTypeMismatchException;
 import org.hibernate.sql.results.spi.RowTransformer;
 
 import java.lang.reflect.Constructor;
@@ -32,6 +33,10 @@ public RowTransformerConstructorImpl(
 			TupleMetadata tupleMetadata,
 			TypeConfiguration typeConfiguration) {
 		this.type = type;
+		if ( tupleMetadata == null ) {
+			throw new QueryTypeMismatchException( "Result type '" + type.getSimpleName()
+												+ "' cannot be used to package the selected expressions" );
+		}
 		final List<TupleElement<?>> elements = tupleMetadata.getList();
 		final List<Class<?>> argumentTypes = elements.stream()
 				.map( RowTransformerConstructorImpl::resolveElementJavaType )