2012/2/27 Daniel-Constantin Mierla daniel@kamailio.org:
However, there is a mismatching between the xml standards and SIP/SIMPLE specs. In XML, the namespaces are bound to prefixes, while the guys at IETF added by their own so called default namespace, which has no prefix for it. That results in not being able to use directly xpath from libxml2 with SIMPLE bodies.
There were some discussions out there (you can google, iirc Inaki was in couple of them), in one side, the devs of libxml2 said they don't want to break XML standards by allowing bogus xpath queries with such namespaces.
Right. IETF SIMPLE group decided to break xpath 1.0 compatibility (what libxml2 implements) to save just a fews bytes in the XML ! Really annoying.
Some time ago I did an ugly workaround in a C project to "fix" it. What Daniel suggests is similar and unfortunately is the way to go in this century.