EllisLab/CodeIgniter — pull request #1710 by samson-htw (2012-08-15 00:18:20+00:00)
Title: Suppress duplicate cookies

Suppress multiple instances of the same cookie being sent when multiple calls to Session::set_userdata are made. Currently, a call to _set_cookie is made on every call to set_userdata, and _set_cookie calls php's setcookie.