The xmlrpc interface is currently invoked if the content type
is text/xml. That is insufficient however if we want to allow
other mechanisms (e.g. REST in issue 2550734) which may also
consume xml format data (in addition to json ...).

Every other rpc interface I am familiar with has a single
known url path by which it is invoked.

I suggest applying the attached patch to cgi/client.py to
put the xmlrpc interface at the xmlrpc path under the tracker.

E.G. to use the xmlrpc interface with the demo tracker:

>>> import xmlrpclib
>>> roundup_server =
xmlrpclib.ServerProxy('http://admin:admin@localhost:8917/demo/xmlrpc',
allow_none=True)

and then any of the xmlrpc interface commands can be used.