Exception when running query removes group by and having fields

What steps will reproduce the problem?
1. Create a query.
2. Enable grouping.
3. Change the query so it fails (add an invalid grouping clause, sum a
varchar field, etc).

When an exception occurs the result tables are removed and the log is
shown. Removing the result tables removes the group by and having fields
that were added to the table. This is annoying if changing the grouping of
a column or adding an invalid having clause caused the exception as the
only way to remove the exception is removing all grouping which will lose
work the user did.

Original issue reported on code.google.com by ThomasOB...@gmail.com on 4 Mar 2009 at 4:26

andreas5588 / wabit

Exception when running query removes group by and having fields #7