Opened with compat but someone reported the same trouble with core on the irc channel, on compat a simple

$ python login.py

Password for user Phe-bot on wikipedia:fr
No characters will be shown
xxxxxx
Should be logged in now

$ python login.py -test
You are not logged in on wikipedia:fr.

The cookie seems fine for the first run

[{'cookieprefix': 'None', 'centralauth_Session': '8c5318ab60af405a5b4c9ca0700b4d47', 'frwikiSession': 'e9f77b61c9a44a54b1cfe999473861f7', 'GeoIP': 'My geo loc here:v4', 'centralauth_Token': 'deleted', 'centralauth_User': 'Phe-bot', 'forceHTTPS': 'true', 'frwikiToken': 'deleted', 'frwikiUserName': 'Phe-bot', 'frwikiUserID': '4507'}, None]

with the $ python login.py -test the same cookie are sent back to the server when doing the userinfo request but the server answer

{u'query': {u'userinfo': {u'name': u'My_IP here', u'rights': [u'createaccount', u'read', u'edit', u'createpage', u'createtalk', u'writeapi', u'editmyusercss', u'editmyuserjs', u'viewmywatchlist', u'editmywatchlist', u'viewmyprivateinfo', u'editmyprivateinfo', u'editmyoptions', u'centralauth-merge', u'abusefilter-log', u'vipsscaler-test'], u'ratelimits': {u'emailuser': {u'ip': {u'seconds': 86400, u'hits': 5}}, u'edit': {u'ip': {u'seconds': 60, u'hits': 8}}, u'linkpurge': {u'ip': {u'seconds': 60, u'hits': 30}}, u'mailpassword': {u'ip': {u'seconds': 3600, u'hits': 5}}, u'renderfile': {u'ip': {u'seconds': 30, u'hits': 700}}, u'renderfile-nonstandard': {u'ip': {u'seconds': 30, u'hits': 70}}}, u'anon': u'', u'preferencestoken': u'+\\', u'groups': [u'*'], u'id': 0}}}

Version: compat-(1.0)
Severity: major