Fix crash in -var-delete

[Joel Brobecker]

> > Can you also please commit to the branch?
> 
> Done.

Thank you.

> > I suggest that we add a NEWS entry as well for every fixes that we make
> > on the branch, that really helps my work when writing the announcement
> > of a new release.
> 
> Can you clarify if you want a NEWS entry to be checked in on trunk, on
> branch, or both?

Just the branch. This should be an RFA because it's a documentation
change, and it is not obvious that this change will be accepted.
I don't think this is a diversion of the purpose of the NEWS files,
but others may disagree.

Thank you,
-- 
Joel