discourse/discourse — pull request #2802 by cpradio (2014-09-16 01:15:42+00:00)
Title: FIX: Firefox - Topic List Keyboard shortcut Previous(K) does not scroll properly leaving selected item hidden

Using k wouldn't always bring the topic in focus as you moved up the topic list, now the functionality behaves exactly the same way Chrome does.
https://meta.discourse.org/t/topic-list-keyboard-shortcut-previous-k-does-not-scroll-properly-leaving-selected-item-hidden-firefox/20050