Grzegorz Olędzki Thanks for the trees. That helps a lot. TO your questions/points:

1. Alot of times in this Antlr-based query parsing code there are badly named identifiers and odd code mainly because the main person that wrote this code did not understand Hibernate very well (and Gavin and I did not understand Antlr enough at the time to help/direct him properly). It really needs an overall re-write.
2. the isScalarSelect thing could just have been an oversight. Originally the individual select expressions were handled much differently. I added the notion of SelectExpression (and therefore SelectExpression#isScalar) later. It does seem that the non-scalar SelectExpression is being rendered twice, so it is very likely this is the problem (or one of them anyway).

Anyway, I will look into this.