The borders look like Firefox's styling for active or focused <a> elements, the watch star is an <a> element, and we apply a rotation animation to it when clicked.

Also, it looks hilarious.

This might be a regression from Krinkle's 678b4d554 / bug 64934.

Assuming we want to keep the outline normally, the simplest fix for this would be '#ca-unwatch.icon a.loading, #ca-watch.icon a.loading { outline: none; }'. The watch star shouldn't really be clickable during the animation anyway (although it currently is, which is a separate bug).

Change 133894 had a related patch set uploaded by Bartosz Dziewoński:
vector: Suppress watch star focus outline when animating it

https://gerrit.wikimedia.org/r/133894

Change 133895 had a related patch set uploaded by Bartosz Dziewoński:
mediawiki.page.watch.ajax: Disable watch link while waiting for API response

https://gerrit.wikimedia.org/r/133895

Change 133894 merged by jenkins-bot:
vector: Suppress watch star focus outline when animating it

https://gerrit.wikimedia.org/r/133894

Change 134070 had a related patch set uploaded by Bartosz Dziewoński:
vector: Suppress watch star focus outline when animating it

https://gerrit.wikimedia.org/r/134070

Change 134070 merged by jenkins-bot:
vector: Suppress watch star focus outline when animating it

https://gerrit.wikimedia.org/r/134070

• Bug 65853 has been marked as a duplicate of this bug. ***

bug 64934 has been backported?

This was backported to 1.23 too, https://gerrit.wikimedia.org/r/#/c/134070/.