[xml] Xinclude recursive fallback bug

[Elliotte Rusty Harold <elharo metalab unc edu>]

Using the latest version of xmllint --xinclude that I compiled today 
(Thanks!) I noticed that it fails to properly process this document:

<?xml version='1.0'?>
<test>
  <xi:include href="missing.xml" 
xmlns:xi="http://www.w3.org/2001/XInclude";><xi:fallback><xi:include 
href="simple.xml"/></xi:fallback></xi:include>
</test>

In particular, it does not resolve the second include element inside the 
fallback element. Instead it produces this document (modulo however my 
e-mail client wraps the long lines)

<?xml version='1.0'?>
<test>
  <xi:include href="missing.xml" 
xmlns:xi="http://www.w3.org/2001/XInclude";><xi:fallback><xi:include 
href="simple.xml"/></xi:fallback></xi:include>
</test>

It should have found and processed the file simple.xml. In the event it 
couldn't find it should have thrown an error. The finished document 
should not contain any include elements.

--
Elliotte Rusty Harold