silverstripe/silverstripe-subsites — pull request #63 by mateusz (2012-10-25 23:14:29+00:00)
Title: BUG Switch the subsite on GET parameter only.

This fixes the bug where creating the top level pages is broken whenever
subsites module is installed. This is because the SubsiteID is
explicitly specified on AddForm POST submission, which incorrectly
triggers a redirect from LeftAndMainSubsites::init and the form action
never has a chance to execute.

Also do not look at POST when checking for the current subsite ID.