Comment 7 for bug 1399246

Since this is a non-trivial change, and it only affects sites using clean URL subdomains, I'm not going to take the risk of backporting it to 1.9 and 1.8.

But to anyone out there running a 1.9 or 1.8 site who encounters this problem, you can probably fix it by cherry-picking my patch for 1.10: https://reviews.mahara.org/4131