Currently, null Strings are converted to empty ones. This makes W3C tests fail: XPathNSResolver_lookupNamespaceURI_nist_dmstc XPathNSResolver_lookupNamespaceURI_null From the spec: Return Value DOMString Returns the associated namespace URI or null if none is found.
Created attachment 12805 [details] proposed fix
Comment on attachment 12805 [details] proposed fix r=me
Landed in r19269.