EllisLab/CodeIgniter — Issue #1146: Incorrect using of Cache-controls in /system/helpers/download_helper.php
Author: CompuRoot
Created: 2012-03-08 15:00:28+00:00
State: open

If both "post-check" and "pre-check" are specified and set to 0, both are entirely ignored.

Refference: http://blogs.msdn.com/b/ieinternals/archive/2009/07/20/using-post_2d00_check-and-pre_2d00_check-cache-directives.aspx