EllisLab/CodeIgniter — pull request #1783 by vlakoff (2012-09-11 11:13:08+00:00)
Title: Better server test in redirect() of URL helper

"Location" header bugs are specific to IIS; previous test was matching
all HTTP servers under Windows.

This test isn't perfect yet ($_SERVER['SERVER_SOFTWARE'], which
corresponds to the "Server" header of HTTP response, might be missing),
but there is no perfect test.

"Refresh" method makes the window blank for quite a noticeable time,
so let's not affect other servers because of IIS.