With Chromium, but not Firefox, the diff section of the editor at the URL has scroll buttons even though it's a single line. The text actually has space enough to be shown completely so this doesn't produce any actual problem, at least in this case.
Version: unspecified
Severity: minor
URL: https://translatewiki.net/w/i.php?title=EOL:Website-updated_community/it&action=edit&loadgroup=%21recent&loadtask=untranslated