Pkg xen devel - Feb 2011 - Bug#587090: The patch is not enough

Also with an vfb line in the config things go wrong.

In fact everywhere where posixpath.py functions get called without a valid
actual parameter, it will crash as there will be no rfind method available.

Personally, I think the posixpath.py should validate it's input and that
that should be fixed.

Kind regards,
Stephan