HHH-18582 Throw explicit error when trying to map nested arrays

Author: mbellade

hibernate-core/src/main/java/org/hibernate/type/descriptor/java/ArrayJavaType.java

@@ -10,6 +10,7 @@
 import java.util.Collection;
 
 import org.hibernate.HibernateException;
+import org.hibernate.MappingException;
 import org.hibernate.SharedSessionContract;
 import org.hibernate.dialect.Dialect;
 import org.hibernate.engine.jdbc.BinaryStream;
@@ -70,7 +71,7 @@ public BasicType<?> resolveType(
 				|| elementJavaTypeClass != null && elementJavaTypeClass.isArray()
 				&& elementJavaTypeClass != byte[].class ) {
 			// No support for nested arrays, except for byte[][]
-			return null;
+			throw new MappingException( "Nested arrays (with the exception of byte[][]) are not supported" );
 		}
 		final ArrayJavaType<T> arrayJavaType;
 		if ( getElementJavaType() == elementType.getJavaTypeDescriptor() ) {