[xml] Question about default namespace with XML Schema

[GUY Fabrice <fabrice guy gmail com>]

Hi,

I'm using this schema :

<?xml version="1.0" encoding="ISO-8859-1"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema";>
  <xsd:element name="ELEMENTS">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="element" type="xsd:string" minOccurs="0"
maxOccurs="unbounded"/>
        <xsd:element name="element2" type="xsd:string" minOccurs="0"
maxOccurs="unbounded"/>
      </xsd:sequence>
    </xsd:complexType>
    <xsd:key name="key">
      <xsd:selector xpath="element"/>
      <xsd:field xpath="."/>
    </xsd:key>
    <xsd:keyref name="keref" refer="key">
      <xsd:selector xpath="element2"/>
      <xsd:field xpath="."/>
    </xsd:keyref>
  </xsd:element>
</xsd:schema>

with this xml file :

<?xml version="1.0" encoding="ISO-8859-1"?>
<ELEMENTS>
    <element>test1</element>
    <element>test2</element>
    <element2>test2</element2>
</ELEMENTS>

And that works perferctly fine.

But when I try to use the default namespace in the schema (to avoid
using the xsd: prefix), I get this message when I validate it with
xmllint :
test.xsd:14: element keyref: Schemas parser error : keyRef 'keref':
References from this schema to components in the namespace
'http://www.w3.org/2001/XMLSchema' are not valid, since not indicated
by an import statement.

Here's my schema with the default namespace :

<?xml version="1.0" encoding="ISO-8859-1"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema";>
  <element name="ELEMENTS">
    <complexType>
      <sequence>
        <element name="element" type="string" minOccurs="0"
maxOccurs="unbounded"/>
        <element name="element2" type="string" minOccurs="0"
maxOccurs="unbounded"/>
      </sequence>
    </complexType>
    <key name="key">
      <selector xpath="element"/>
      <field xpath="."/>
    </key>
    <keyref name="keref" refer="key">
      <selector xpath="element2"/>
      <field xpath="."/>
    </keyref>
  </element>
</schema>

Have I missed something (namespace declaration,...) or this is a bug ?

Fabrice