[xml] problems with entity in default namespace declaration

[Lars Weber <lars digiterror net>]

Greetings,

does anyone know what could be the reason for xmllint outputting

        test.rdf:8: parser warning : xmlns: URI &foo; is not absolute
        <foo xmlns="&foo;"
                          ^

when confronted with the following document

        <?xml version="1.0"?>
        
        <!DOCTYPE foo [
        <!ENTITY foo "http://foo.org/";>
        <!ENTITY bar "http://bar.org/";>
        ]>
        
        <foo xmlns="&foo;"
             xmlns:bar="&bar;">
        
        </foo>

?

When I exchange the entity reference &foo; with http://foo.org/ I don't
get the above warning.

Regards,
Lars