Code review comment for lp:~brian-murray/launchpad/limited-subscriptions-page

The Continue button shows the same behaviour for me, but what is weird is that they work as we expect in the test.

I couldn't figure out what is going on, but this might be related to the fact that ReturnToReferrerMixin must be mixed into a LaunchpadFormView, but here it was mixed into a LaunchpadView. That mixin works by storing a hidden field (_return_url) in the page's form and mapping that field to a view property with the same name. Here the hidden field is not stored automatically by the mixin as the page does not use launchpad-form.pt (since it's not a LaunchpadFormView), so the hidden field is created manually. The hidden field created manually has a different name, though ('next_url'), so the mixin's _return_url property would always return None. That's consistent with the behaviour I see on the two browsers I've tested (chromium and epiphany), but is not consistent with the behaviour shown by the tests.