If I visit action=watch logged out, I get:
You must be <a href="/wiki/Special:UserLogin" title="Special:UserLogin">logged in</a> to modify your watchlist.
Return to <a href="/wiki/MediaWiki" title="MediaWiki">MediaWiki</a>.
The Special:UserLogin URL should include a returnto parameter so that after logging in/registering the user can at least get back to the original page.
Version: 1.23.0
Severity: normal
URL: https://www.mediawiki.org/wiki/Requests_for_comment/Performance_standards_for_new_features?action=watch