Using Nested DetachedCriteria (Sub-Selects) throwing NullPointerException

Hi,
We have come across an issue with the usage of nested subselects in the sql query with hibernate 3.2.5.

We get the following exception when there is more than one level of sub-selects in the query :
---------------------------------------------------------------------------------------------------------------------- java.lang.NullPointerException
at org.hibernate.criterion.SubqueryExpression.getTypedValues(SubqueryExpression.java:80)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getQueryParameters(CriteriaQueryTranslator.java:251)
at org.hibernate.criterion.SubqueryExpression.toSqlString(SubqueryExpression.java:55)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getWhereCondition(CriteriaQueryTranslator.java:334)
at org.hibernate.loader.criteria.CriteriaJoinWalker.<init>(CriteriaJoinWalker.java:71)
at org.hibernate.loader.criteria.CriteriaLoader.<init>(CriteriaLoader.java:67)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1550)
at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:283)
at NestedDetachedCriteriaTest.testNestedDetachedCriteria(Unknown Source)
----------------------------------------------------------------------------------------------------------------------
The actual query that gets fired is like:
---------------------------------------------------------------------------------------------------------------------- select this_.name as y0_ from cat this_ where this_.name =
(select this0_.name as y0 from cat this0__ where this0__.parent_id =
(select this0_.parent_id as y0 from cat this0__ where this0__.name =
(select this0_.name as y0 from cat this0__ where this0__.cat_id = ?)))
----------------------------------------------------------------------------------------------------------------------

We investigated the issue and have fixed it by making some changes in org.hibernate.criterion.SubqueryExpression class.

The attached file has the following contents:
1. SubqueryExpression.java - Fix we have made to SubqueryExpression class.
2. NestedDetachedCriteriaTest.zip - A test case to highlight the nested sub-select issue (testNestedDetachedCriteria).

Regards,
Roshan