[mod_python] More translation handler help?

With a little bit of help from Grisha, I got past my first problem (I needed
a writable req.uri)
and am onto a second one.

I stripped out the following handlers from a much larger system, and they
reproduce the problem.
The production handler (handler) attempts to do a lookup_uri on the inbound
URI. If there is no translation handler
called for in the conf file, all is well, and the lookup works.

If there is a translation handler declared using PythonTransHandler, the
Transhandler gets called twice,
and the server process appears to go into a loop -- never exits the
production handler. I'm suspecting
that there is a reentrancy issue here of some sort, but the Apache code
specifically suggests calling lookup_uri() to
get the mapping of "/" to filename, instead of using document_root().

Comments on the rules of when one can and can't call lookup_uri() would be
welcome.

-- Sean


Configuration:

# Connections for general test site
<VirtualHost www.foo.com>
    DocumentRoot /usr/local/apache/htdocs/www.foo.com
    ServerName www.foo.com
    AddHandler python-program .phtml
    PythonInterpreter xphtml
    PythonHandler phtml.xphtml
    PythonTransHandler phtml.xphtml
</VirtualHost>


xphtml.py:



from mod_python import apache
from phtmllog import log, logIO

def transhandler(req):
    log("transhandler "+`req.uri`)
    return apache.DECLINED

def handler(req):
    log("lookup_uri "+req.lookup_uri(req.uri).filename)
    return apache.OK


requestobject.c code for lookup_uri:

/**
 ** request.lookup_uri(request self, uri)
 **
 *    An interface to the ap_lookup_uri function.
 */

static PyObject * req_lookup_uri(requestobject *self, PyObject *args)
{
  const char *uri;
  request_rec *req;


  if (! PyArg_ParseTuple(args, "s", &uri))
    return NULL;

  req = (request_rec *)ap_sub_req_lookup_uri(uri,self->request_rec);
  if (! req) {
    Py_INCREF(Py_None);
    return Py_None;
  }
  else {
    return MpRequest_FromRequest(req);
  }
}


...


    {"lookup_uri",           (PyCFunction) req_lookup_uri,
METH_VARARGS},
    { NULL, NULL } /* sentinel */
};

...