Splitting this from bug 40329, $wgCleanupPresentationalAttributes should be killed from MediaWiki core. It was introduced in r94465 to try to magically transform particular deprecated and invalid attributes into their CSS equivalents.
I don't believe these types of magical transformations are a good idea and the introduction of this code appears to have caused more problems than it has solved. I strongly urge that this global configuration variable and its related code be removed before the release of 1.20.
Version: unspecified
Severity: blocker
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=39614
https://bugzilla.wikimedia.org/show_bug.cgi?id=66413