> My opinion based on some tests + practice is that the semantics of the
> "for select" are not well defined in this case, and they depend on
> various implementation aspects that make the code unpredictable and
> unportable. What do you think?

I think that you must not change anything that can affect result of
select. It is about the same as you won't change loop variables in any
other programming language. Even if some languages allow loop variables
(counter or limits) to be changed, it is up to you as a developer to
take responsibility for your actions. If you are not clever enough to
predict results - just don't do it.

SY, SD.