Tests XD0016 is raised, when @select returns an attribute.
Test ab-input-028.xml is expected to fail with error code err:XD0016.
<p:declare-step xmlns:err="http://www.w3.org/ns/xproc-error" xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
   <p:input port="source" select="/doc/@att1">
      <doc att1="1" att2="2">
   </p:input>
   <p:output port="result">
   <p:identity/>
</p:declare-step>
Changed test because an atomic result of select is not an error anymore, but an attribute is.
Fix namespace declarations
More tests.