quoted urls UnicodeDecodeError

I use quoted URLs such as /fr/livres/cr%C3%A9ation/ (for /fr/livres/création/).
get() is working fine with these urls but once I have the response if I try to use click() or submit() on it I get the following error:

/usr/lib/python3.3/http/cookiejar.py:1588: UserWarning: http.cookiejar bug!
Traceback (most recent call last):
  File "/usr/lib/python3.3/http/cookiejar.py", line 1586, in make_cookies
    parse_ns_headers(ns_hdrs), request)
  File "/usr/lib/python3.3/http/cookiejar.py", line 1543, in _cookies_from_attrs_set
    cookie = self._cookie_from_cookie_tuple(tup, request)
  File "/usr/lib/python3.3/http/cookiejar.py", line 1492, in _cookie_from_cookie_tuple
    req_host, erhn = eff_request_host(request)
  File "/usr/lib/python3.3/http/cookiejar.py", line 612, in eff_request_host
    erhn = req_host = request_host(request)
  File "/usr/lib/python3.3/http/cookiejar.py", line 597, in request_host
    url = request.get_full_url()
  File "/usr/local/lib/python3.3/dist-packages/WebTest-2.0.8.dev0-py3.3.egg/webtest/utils.py", line 116, in get_full_url
    return self._request.url
  File "/usr/local/lib/python3.3/dist-packages/WebOb-1.2.3-py3.3.egg/webob/request.py", line 505, in url
    url = self.path_url
  File "/usr/local/lib/python3.3/dist-packages/WebOb-1.2.3-py3.3.egg/webob/request.py", line 477, in path_url
    bpath_info = bytes_(self.path_info, self.url_encoding)
  File "/usr/local/lib/python3.3/dist-packages/WebOb-1.2.3-py3.3.egg/webob/descriptors.py", line 68, in fget
    return req.encget(key, encattr=encattr)
  File "/usr/local/lib/python3.3/dist-packages/WebOb-1.2.3-py3.3.egg/webob/request.py", line 167, in encget
    return bytes_(val, 'latin-1').decode(encoding)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe9 in position 5: invalid continuation byte

  _warn_unhandled_exception()

I'm using Ubuntu 13.04 64 bit and Python 3.3.1 with the last commit of Webtest.

Reproduce the failure with the quoted URL and then call click() or submit() on the response. Start with webtest/utils.py get_full_url and the WebOb request.py path_url and descriptors.py encget frames shown in the traceback; done means these actions no longer raise UnicodeDecodeError.