In T32965#1792493, @Glaisher wrote:

In T32965#1776898, @Schnark wrote:

This looks really ugly for lists containig only one item with a space (at least in FF 41):

I can also observe this issue on the page in your screenshot on FF and Chrome as well. No idea why this is happening on that specific query but it doesn't always happen when there's only one item with a space. The only place where I could see this issue was the one which you linked. It does appear to be fixed in some column-gaps. Will investigate this more later and try to submit a fix.

So I think that the root issue here is that the browser is trying to render it as it would appear for 3 columns even if we've just one entry in the resultset. I tried playing around with the CSS but it doesn't appear correctly on all screens so I think the best thing to do here would be to just show a normal list if there's less than 3 entries. CategoryViewer also does this.

Change 252007 had a related patch set uploaded (by Glaisher):
Don't apply CSS columns if less than 3 results were found on AllPages & PrefixIndex

https://gerrit.wikimedia.org/r/252007

Change 252007 merged by jenkins-bot:
Don't apply CSS columns if less than 3 results were found on AllPages & PrefixIndex

https://gerrit.wikimedia.org/r/252007

Well done!