Backported r3080 from trunk (#4248).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/branches/0.8-stable@3081 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/controllers/account_controller.rb

@@ -188,12 +188,12 @@ class AccountController < ApplicationController
   
 private
   def logged_user=(user)
+    reset_session
     if user && user.is_a?(User)
       User.current = user
       session[:user_id] = user.id
     else
       User.current = User.anonymous
-      session[:user_id] = nil
     end
   end
 end