Tests p:filter with an unused element name.
Test ab-filter-002.xml is expected to pass.
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:output port="result"/>
<p:filter select="/someunknownelement">
<p:with-input>
<doc>
<?pi test?>
<p>This is a p.</p>
</doc>
</p:with-input>
</p:filter>
<p:wrap-sequence wrapper="result"/>
</p:declare-step>
<s:schema xmlns="http://www.w3.org/1999/xhtml" xmlns:s="http://purl.oclc.org/dsdl/schematron" queryBinding="xslt2">
<s:pattern>
<s:rule context="/">
<s:assert test="result">Root element is not 'result'.</s:assert>
<s:assert test="empty(result/*)">Root element should have no children.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
Ported test from XProc (1.0) test suite.