xmllint, xinclude, xpointer, and DocBook 5.0

["Dick Hamilton" <rlhamilton@frii.com>]

I'm running into a problem using xmllint to resolve xincludes
in DocBook 5.0.  I'm running xmllint 2.6.31, which I believe
is the latest stable version, on Linux.  The only argument I'm
using on xmllint is --xinclude.

I have no problem with a vanilla xinclude that just pulls in
the entire file like this:

<xi:include xmlns:xi="http://www.w3.org/2001/XInclude";
            href="chap1.xml"/>

or one that uses xpointer with the element expression like this:

<xi:include xmlns:xi="http://www.w3.org/2001/XInclude";
            href="chap1.xml"
            xpointer="element(idvalue)"/>

But, xmllint fails if I use an xpointer expression like this:

<xi:include xmlns:xi="http://www.w3.org/2001/XInclude";
            href="chap1.xml"
            xpointer="xpointer(//chapter/title/node())"/>

After playing around for a while, I found that xmllint will work
with DocBook 5.0 if I remove xmlns="http://docbook.org/ns/docbook";
from the parent element in the included file.  The xmlns attribute
is a no-op on the including file; xmllint fails whether the namespace
is there or not.

Since removing xmlns makes the included file invalid, doing that is
not a practical long term solution.

Does anyone know a way to get xmllint (or some alternate processor)
to handle xincludes with xpointer in DocBook 5.0?

Thanks,
Dick Hamilton
rlhamilton@frii.com