Switching to side-by-side diff continuously redirects anonymous users to login form

How to reproduce:
1. Make any repo in Stash public
2. Log out, or access Stash unauthenicated in any other way
3. Pull up any file directly through the repo browser or on a commit detail page
4. View the diff to the previous version of the file
5. Switch the default diff style from "Unified diff" to "Side-by-side diff".

Expected behavior:
Stash will display the diff in side-by-side style.

Actual behavior:
Stash will redirect you to the login form. Attempting to use the back button of your browser gets you back for a split second, then Stash redirects you back to the login form again.
If you try to just click your way through to the file again via the Stash start page link in the navigation bar on top of the page, you will immediately be redirected to the login form again as soon as you pull up any other page with a diff view (obviously Stash sets a cookie with preferred display options). I've even deleted any cookie belonging to the domain I run my Stash instance on in the browser I used to test and still I get redirected. Update: You don't even have to pull up a diff view page, you already get redirected if you just try to view the source of a file.