For an HQL query like:

select firstName, null, lastName from Person where lastName=?"

Hibernate assumes there was only 1 select expression returned by the query. The null select expression seems to be interpreted as "no more select expressions". (null and lastName are ignored). The query returns a String object instead Object[].of length 3.

If NULL is not allowed as a select expression, an exception should be thrown instead of silently ignoring the select expressions.