[xml] Retrieve all namespaces

[Martin Siggel <martinsiggel+xml gmail com>]

Dear Daniel and all other XML list readers,

I am a relatively new user to libxml. I am writing on a simplified
interface for libxml.

In this interface, I would like to register all prefixes / namespaces
for the xpath interface using xmlXPathRegisterNs, that appear in an
xml file.

Is there any function in libxml, to retrieve a list of all namespace
and prefixes used in the xml file?

Many thanks,
Martin