Fix switching of view modes in text-type file attachment diffs.
Review Request #12430 — Created July 1, 2022 and submitted
The view mode selector ("rendered" vs "source") wasn't working when
viewing a diff of a text-based file attachment. We initially noticed
this with the Markdown review UI, but it affects all text-based
reviewables that support render modes. The issue here is that we were
passing in a
Backbone.historythat wasn't properly including
the diff file attachment ID. Because the root didn't match, the route
would never get triggered when the URL changed after the anchor was
Viewed a markdown file attachment in both single-revision and diff
views. Verified that switching between "rendered" and "source" worked
properly for both.
If we're going to use parens here, we can move the ? and : inside of it, aligned with the …