[soc2009/http-wsgi-improvements] http.HttpResponse now initializes self._codec to None.

Changeset 11030 did not actually pass the regression test suite. This passes all except two tests, from test_client_regress. They expect old behavior (which is that their responses will be encoded in settings.DEFAULT_CHARSET). I am not yet sure if that is the correct expectation for the test to have, so I will do investigations into that.

git-svn-id: http://code.djangoproject.com/svn/django/branches/soc2009/http-wsgi-improvements@11040 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/http/__init__.py

@@ -276,6 +276,7 @@ class HttpResponse(object):
             content_type=None, request=None):
         from django.conf import settings
         self._charset = settings.DEFAULT_CHARSET
+        self._codec = None
         accept_charset = None
         if mimetype:
             content_type = mimetype     # Mimetype is an alias for content-type