Erik Hansen which version of pdb was this?
In newer versions, I suspect this should be handled by the "universal" null escaping here: https://github.com/puppetlabs/puppetdb/blob/master/src/puppetlabs/puppetdb/cheshire.clj#L118
And note that puppetdb cannot store unicode nulls in string values (hence that mangling above).
Erik Hansen we know what's going on now – the package inventory isn't currently subject to the null rewriting mentioned above. cf. PE-22576