QXmlQuery + XSLT2 + function -> problems

Using <xsl:function> with QXmlQuery is buggy. The following code

QString out;
QXmlQuery query(QXmlQuery::XSLT20);
query.setFocus(QUrl(xmlf));
query.setQuery(QUrl(xslf));
query.evaluateTo(&out);

should have resulted in

99 gives P 99P
-88 gives N -88N

however it gives

99 gives P 99P
-88 gives N 99P

The function in the 'bad' namespace for some reason is seeing only the very first node and thereafter nothing new. I attach the XSL and XML.