HHH-12067: NativeQueryTupleTransformer doesn't handle null values in returned ResultSet

hibernate-core/src/main/java/org/hibernate/jpa/spi/NativeQueryTupleTransformer.java

@@ -81,12 +81,11 @@ public class NativeQueryTupleTransformer extends BasicTransformerAdapter {
 
 		@Override
 		public Object get(String alias) {
-			Object tupleElement = aliasToValue.get( alias.toLowerCase() );
+			final String lowerCasedAlias = alias.toLowerCase();
-
+			if (!aliasToValue.containsKey(lowerCasedAlias)) {
-			if ( tupleElement == null ) {
 				throw new IllegalArgumentException( "Unknown alias [" + alias + "]" );
 			}
-			return tupleElement;
+			return aliasToValue.get(lowerCasedAlias);
 		}
 
 		@Override

hibernate-core/src/test/java/org/hibernate/jpa/spi/NativeQueryTupleTransformerTest.java

@@ -0,0 +1,35 @@
+package org.hibernate.jpa.spi;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import javax.persistence.Tuple;
+
+import org.junit.Test;
+
+/**
+ * @author Maksym Symonov
+ */
+public class NativeQueryTupleTransformerTest {
+
+    private final NativeQueryTupleTransformer nativeQueryTupleTransformer = new NativeQueryTupleTransformer();
+
+    @Test
+    public void nullValueIsExtractedFromTuple() {
+        final Tuple tuple = (Tuple) nativeQueryTupleTransformer.transformTuple(
+            new Object[] { 1L, null },
+            new String[] { "id", "value" }
+        );
+        assertEquals(1L, tuple.get("id"));
+        assertNull(tuple.get("value"));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void missingAliasCausesExceptionWhenIsExtractedFromTuple() {
+        final Tuple tuple = (Tuple) nativeQueryTupleTransformer.transformTuple(
+            new Object[] { 1L, null },
+            new String[] { "id", "value" }
+        );
+        tuple.get("unknownAlias");
+    }
+}

hibernate-core/src/test/java/org/hibernate/jpa/test/query/TupleNativeQueryTest.java

@@ -18,6 +18,7 @@ import java.util.stream.Collectors;
 import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 
 @RequiresDialect(H2Dialect.class)
 public class TupleNativeQueryTest extends BaseEntityManagerFunctionalTestCase {
@@ -700,12 +701,17 @@ public class TupleNativeQueryTest extends BaseEntityManagerFunctionalTestCase {
         });
         doInJPA(this::entityManagerFactory, entityManager -> {
             List<Tuple> tuples = getTupleResult(entityManager);
-            List<TupleElement<?>> result = tuples.get(0).getElements();
+            final Tuple tuple = tuples.get(0);
+            List<TupleElement<?>> result = tuple.getElements();
             assertEquals(2, result.size());
-            assertEquals(BigInteger.class, result.get(0).getJavaType());
+            final TupleElement<?> firstTupleElement = result.get(0);
-            assertEquals("id", result.get(0).getAlias());
+            assertEquals(BigInteger.class, firstTupleElement.getJavaType());
-            assertEquals(Object.class, result.get(1).getJavaType());
+            assertEquals("id", firstTupleElement.getAlias());
-            assertEquals("firstname", result.get(1).getAlias());
+            assertEquals(BigInteger.valueOf(1L), tuple.get(firstTupleElement.getAlias()));
+            final TupleElement<?> secondTupleElement = result.get(1);
+            assertEquals(Object.class, secondTupleElement.getJavaType());
+            assertEquals("firstname", secondTupleElement.getAlias());
+            assertNull(tuple.get(secondTupleElement.getAlias()));
         });
     }