title says it all - if you set $wgStyleDirectory = "$IP/foo" one would expect the resource loader to look in foo not skins for the bits in skins, but it has skins hardcoded.
On the other hand I personally don't see what benefit wgStyleDirectory has over using a symbolic link if you really had to have the style directory somewhere else than the default, so perhaps the global should just be removed...
Version: 1.17.x
Severity: minor