Found while testing patch for bug 10387.
The little splash screen with the logo and installer link when you go to a MediaWiki directory prior ot installation makes assumptions about paths. It strips 'index.php' without checking for other things, which can leave you with a bogus path to the logo and installer if you went to 'index.php5'.
A pretty easy fix.
Version: 1.11.x
Severity: trivial