silverstripe/sapphire — pull request #371 by halkyon (2012-04-26 04:51:51+00:00)
Title: Improvements to session start and Vary header in HTTP

This is a patch taken from an internal project, it fixes SilverStripe Framework to work with HTTP accelerators like Varnish by using a Vary header of "Cookie" instead the current Cache-Control header.

Additionally, we don't start the session until it's actually necessary, which is to say there is a cookie available with the current PHP session name.