xs:keyref not working

[LordOfDragons]

Take an XSD like this one here:

<xs:schema attributeFormDefault='unqualified' elementFormDefault='qualified' xmlns:xs='http://www.w3.org/2001/XMLSchema'>
  <xs:complexType name='source'>
    <xs:attribute name='name' type='xs:string' use='required'/>
  </xs:complexType>

  <xs:complexType name='target'>
    <xs:choice minOccurs='0' maxOccurs='unbounded'>
      <xs:element name='reference' type='xs:string'/>
    </xs:choice>
  </xs:complexType>

  <xs:complexType name='root'>
    <xs:choice minOccurs='0' maxOccurs='unbounded'>
      <xs:element name='source' type='source'/>
      <xs:element name='target' type='target'/>
    </xs:choice>
  </xs:complexType>

  <xs:element name='root' type='root'>
    <xs:unique name='unique.source.name'>
      <xs:selector xpath='source'/>
      <xs:field xpath='@name'/>
    </xs:unique>
    <xs:keyref name='keyref.target.reference' refer='unique.source.name'>
      <xs:selector xpath='target'/>
      <xs:field xpath='reference'/>
    </xs:keyref>
  </xs:element>
</xs:schema>

with an XML like this:

<root>
  <source name='test1'/>
  <source name='test1'/>
  <target>
    <reference>test2</reference>
  </target>
</root>

The extension will recognize that "test1" is duplicate (xs:unique works) but it will neither recognize that "test2" does not refer to a known name nor does it propose names on completion inside the "reference" tag at all.