HHH-10861 - Fix nullLiteral in select expression

hibernate-core/src/main/java/org/hibernate/hql/internal/ast/SqlASTFactory.java

@@ -15,6 +15,7 @@ import org.hibernate.hql.internal.ast.tree.BinaryArithmeticOperatorNode;
 import org.hibernate.hql.internal.ast.tree.BinaryLogicOperatorNode;
 import org.hibernate.hql.internal.ast.tree.BooleanLiteralNode;
 import org.hibernate.hql.internal.ast.tree.CastFunctionNode;
+import org.hibernate.hql.internal.ast.tree.NullNode;
 import org.hibernate.hql.internal.ast.tree.SearchedCaseNode;
 import org.hibernate.hql.internal.ast.tree.SimpleCaseNode;
 import org.hibernate.hql.internal.ast.tree.CollectionFunction;
@@ -192,6 +193,9 @@ public class SqlASTFactory extends ASTFactory implements HqlSqlTokenTypes {
 			case ENTRY: {
 				return MapEntryNode.class;
 			}
+			case NULL : {
+				return NullNode.class;
+			}
 			default:
 				return SqlNode.class;
 		}

hibernate-core/src/main/java/org/hibernate/hql/internal/ast/tree/NullNode.java

@@ -0,0 +1,38 @@
+/*
+ * 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.hql.internal.ast.tree;
+
+import antlr.SemanticException;
+
+import org.hibernate.engine.spi.SessionFactoryImplementor;
+import org.hibernate.hql.internal.ast.util.ColumnHelper;
+import org.hibernate.type.Type;
+
+/**
+ * @author Andrea Boriero
+ */
+public class NullNode extends AbstractSelectExpression {
+
+	public Type getDataType() {
+		return null;
+	}
+
+	@Override
+	public void setScalarColumnText(int i) throws SemanticException {
+		ColumnHelper.generateSingleScalarColumn( this, i );
+	}
+
+	public Object getValue() {
+		return null;
+	}
+
+	@Override
+	@SuppressWarnings({"unchecked"})
+	public String getRenderText(SessionFactoryImplementor sessionFactory) {
+		return "null";
+	}
+}

hibernate-core/src/main/java/org/hibernate/hql/internal/ast/util/LiteralProcessor.java

@@ -191,6 +191,10 @@ public class LiteralProcessor implements HqlSqlTokenTypes {
 		}
 	}
 
+	public void processNull(AST constant) {
+		constant.setText( "null" );
+	}
+
 	private void processLiteral(AST constant) {
 		String replacement = (String) walker.getTokenReplacements().get( constant.getText() );
 		if ( replacement != null ) {

hibernate-core/src/main/java/org/hibernate/internal/util/ReflectHelper.java

@@ -301,12 +301,14 @@ public final class ReflectHelper {
 	 */
 	public static Constructor getConstructor(Class clazz, Type[] types) throws PropertyNotFoundException {
 		final Constructor[] candidates = clazz.getConstructors();
-		for ( final Constructor constructor : candidates ) {
-			final Class[] params = constructor.getParameterTypes();
+		Constructor constructor = null;
+		int numberOfMatchingConstructors = 0;
+		for ( final Constructor candidate : candidates ) {
+			final Class[] params = candidate.getParameterTypes();
 			if ( params.length == types.length ) {
 				boolean found = true;
 				for ( int j = 0; j < params.length; j++ ) {
-					final boolean ok = params[j].isAssignableFrom( types[j].getReturnedClass() ) || (
+					final boolean ok = types[j] == null || params[j].isAssignableFrom( types[j].getReturnedClass() ) || (
 							types[j] instanceof PrimitiveType &&
 									params[j] == ( (PrimitiveType) types[j] ).getPrimitiveClass()
 					);
@@ -316,12 +318,18 @@ public final class ReflectHelper {
 					}
 				}
 				if ( found ) {
-					constructor.setAccessible( true );
-					return constructor;
+					numberOfMatchingConstructors ++;
+					candidate.setAccessible( true );
+					constructor = candidate;
 				}
 			}
 		}
+
+		if ( numberOfMatchingConstructors == 1 ) {
+			return constructor;
+		}
 		throw new PropertyNotFoundException( "no appropriate constructor in class: " + clazz.getName() );
+
 	}
 	
 	public static Method getMethod(Class clazz, Method method) {

hibernate-core/src/main/java/org/hibernate/query/criteria/internal/expression/NullLiteralExpression.java

@@ -11,6 +11,7 @@ import java.io.Serializable;
 import org.hibernate.query.criteria.internal.CriteriaBuilderImpl;
 import org.hibernate.query.criteria.internal.ParameterRegistry;
 import org.hibernate.query.criteria.internal.compile.RenderingContext;
+import org.hibernate.query.criteria.internal.expression.function.CastFunction;
 
 /**
  * Represents a <tt>NULL</tt>literal expression.
@@ -27,7 +28,7 @@ public class NullLiteralExpression<T> extends ExpressionImpl<T> implements Seria
 	}
 
 	public String render(RenderingContext renderingContext) {
-		return "null";
+		return CastFunction.CAST_NAME + "( 	null  as " + renderingContext.getCastType( getJavaType() ) + ')';
 	}
 
 	public String renderProjection(RenderingContext renderingContext) {