Root_uri check fails if request_uri contains multiple /

[hector.rivas@…]

If you have a root_uri like:

PythonOption TracUriRoot /devel/trac

and you request something like:

https://mysite.com/devel/trac////aproject/changeset/143

This error is raised:

[Mon Nov 20 07:14:00 2006] [error] [client xxxx] PythonHandler trac.web.modpython_frontend: Traceback (most recent call last):
[Mon Nov 20 07:14:00 2006] [error] [client xxx] PythonHandler trac.web.modpython_frontend:   File "/usr/lib/python2.3/site-package
s/mod_python/apache.py", line 299, in HandlerDispatch\n    result = object(req)
[Mon Nov 20 07:14:00 2006] [error] [client xxx] PythonHandler trac.web.modpython_frontend:   File "/var/lib/python-support/python2
.3/trac/web/modpython_frontend.py", line 87, in handler\n    gateway.run(dispatch_request)
[Mon Nov 20 07:14:00 2006] [error] [client xxx] PythonHandler trac.web.modpython_frontend:   File "/var/lib/python-support/python2
.3/trac/web/wsgi.py", line 87, in run\n    response = application(self.environ, self._start_response)
[Mon Nov 20 07:14:00 2006] [error] [client xxx] PythonHandler trac.web.modpython_frontend:   File "/var/lib/python-support/python2
.3/trac/web/main.py", line 262, in dispatch_request\n    raise ValueError('TracUriRoot set to %s but request URL '
[Mon Nov 20 07:14:00 2006] [error] [client xxx] PythonHandler trac.web.modpython_frontend: ValueError: TracUriRoot set to /devel/trac but request URL is /devel/trac////aproject/changeset/143

The problem is in /trac/web/main.py function dispatch_request and can be solved adding a regex substition:

       ...
       if 'TracUriRoot' in options:
            # Special handling of SCRIPT_NAME/PATH_INFO for mod_python, which
            # tends to get confused for whatever reason
            root_uri = options['TracUriRoot'].rstrip('/')
            request_uri = environ['REQUEST_URI'].split('?', 1)[0]

            # Subtitute multiple /
            request_uri = re.sub('/+', '/', request_uri)

            if not request_uri.startswith(root_uri):
                raise ValueError('TracUriRoot set to %s but request URL '
                                 'is %s' % (root_uri, request_uri))
            environ['SCRIPT_NAME'] = root_uri
            environ['PATH_INFO'] = urllib.unquote(request_uri[len(root_uri):])
     ...

[Emmanuel Blot]

I'm not sure that supporting this kind of manually formed URLs is worth adding the cost of a regular expression evaluation for every single request…

[Christian Boos]

That pair of lines seems indeed fragile:

root_uri = options['TracUriRoot'].rstrip('/')

this may remove an arbitrary number of '/'

and:

environ['PATH_INFO'] = urllib.unquote(request_uri[len(root_uri):])

this will leave any remaining leading '/'

I wish there would be more context for that surrounding comment:

# Special handling of SCRIPT_NAME/PATH_INFO for mod_python, which
# tends to get confused for whatever reason

but nevertheless, some simplification of this code block seems to be possible, something like:

root_uri = options['TracUriRoot'].rstrip('/')
request_uri = environ['REQUEST_URI'].split('?', 1)[0]
if not request_uri.startswith(root_uri):
    raise ValueError('TracUriRoot set to %s but request URL '
                     'is %s' % (root_uri, request_uri))
environ['SCRIPT_NAME'] = root_uri.rstrip('/')
environ['PATH_INFO'] = urllib.unquote(request_uri[len(root_uri)-1:])

(untested)

[Christian Boos]

Another obscure mod_python related issue…

If this problem still happens in current versions for someone, please reopen, preferably with a patch.