Found while reviewing patch for bug 10387, triggered via bug 10396.
The AJAX watch/unwatch code is supposed to fallback to the traditional watch/unwatch link if the AJAX request doesn't work.
Unfortunately that fallback isn't actually working. This is usually hidden as failures are unlikely if the AJAX setup code determines that AJAX won't work, but a problem that prevents the request from working on the server end will leave it in failure mode.
The button changes to "watching..." but never changes back.
Error condition should be better detected, and the fallback mode used.
Version: 1.11.x
Severity: normal