xlat expansion of absent VPs

[Alan DeKok]

Arran Cudbard-Bell wrote:
> I have to agree. If an attribute doesn't exist then it should expand to "",
> that's the behaviour i'm used to too.

  For me, it's a major security issue.  Silently missing an attribute is
bad.

> Previously the xlat code wrongly treated zero length expansions as errors,
> this might of been the original reason for returning a one char expansion.

  No, the zero-length expansion issue was a temporary problem during the
re-write of the new code.

  Alan DeKok.