[xml] Preserving namespace prefix when doc does not contain proper NS declaration

[Shane Adams <adamsch1 yahoo com>]

Hi - I searched the archives and looked at the API,
hope I'm not missing something obvious.  I'm parsing
RSS feeds, alot of feeds contain extensions.  These
extra tags should be declared by a proper namespace
declaration, but in many cases they are not.

Is there a way to force libxml2 to parse the document,
and preserve the 'prefix' to a namespace that is not
defined?

Cheers,
  Shane