Below the results, but above the navigation controls at the bottom of the page, a \n appears.
- https://www.mediawiki.org/w/index.php?search=test+search&title=Special%3ASearch&go=Go
- https://meta.wikimedia.org/w/index.php?search=test+search&title=Special%3ASearch&go=Go
This does not appear to be happening on en.wikipedia.org.
I can also reproduce this issue locally using the tip of master: