mootools/mootools-core — pull request #2397 by brianedgerton (2012-08-08 01:14:02+00:00)
Title: Fixes #2396. Feature check for position:fixed support

Feature test for position:fixed support solves failing test in Windows Phone. Runs as expected in FF, Safari, Chrome on OS X and IE7+.

Setting position: fixed in Win Phone yields strange results:

element.setStyle('position', 'fixed');
element.getStyle('position') === 'fixed'
element.style.position === 'fixed'

element.currentStyle.position === 'absolute'

This was causing getOffsetParent() to return an empty div instead of null in this test.