= Description =
The superuser mode for select user is broken and gives the following traceback

{{attachment:FileSessionService_traceback.html}}

= How to reproduce =
 * Have 2 users, one with superuser capabilities (easily tested with standalone).
 * Login as the superuser.
 * Go to preferences, select "switch user"
 * Choose the other user and submit.
 * See the crash.

== Details ==

## If you got a traceback, please save the traceback page as html and attach here:
## [[attachment:traceback.html]]

## if the bug is in this wiki, just kill the table and write: This Wiki.

## If a traceback is not available, please fill in the details here:
|| '''!MoinMoin Version''' || moin-1.9 4429:574644cfc6d2 ||
|| '''OS and Version''' ||  ||
|| '''Python Version''' ||  ||
|| '''Server Setup''' || ||
|| '''Server Details''' || ||
|| '''Language you are using the wiki in''' (set in the browser/UserPreferences) || ||

== Workaround ==
## How to deal with the bug until it is fixed


= Discussion =
{{{
MoinMoin/web/session.py
...
         userobj = request.user
         if userobj and userobj.valid:
             if 'user.id' in session and session['user.id'] != userobj.id:
                 request.cfg.session_service.delete(session) # <-- obviously wrong/non-existant and was never tested
             session['user.id'] = userobj.id
             session['user.auth_method'] = userobj.auth_method
             session['user.auth_attribs'] = userobj.auth_attribs
}}}

= Plan =
## This part is for Moin``Moin developers:

 * Priority: 
 * Assigned to: ThomasWaldmann
 * Status: fixed by http://hg.moinmo.in/moin/1.9/rev/0ac99fdbe65d

----
## If you are a moin core developer, replace the category to Category* in these cases:
## Category MoinMoinNoBug - if this is not a bug.
## Category MoinMoinBugConfirmed - if you can confirm the bug on current code.
## Category MoinMoinBugFixed - after the bug is fixed in current code.
CategoryMoinMoinBugFixed