mootools/mootools-core — pull request #2411 by gonchuki (2012-08-20 20:41:23+00:00)
Title: opacity 1 should not have a nulling effect in oldIE, fixes #2336

this also re-enables the opacity spec to run on IE.
The issue is that there was an incorrect assumption that `setStyle('opacity', 1)` meant removing the filter attribute, when in fact the element could have any other opacity set at the stylesheet level.
Enabled specs are green, pinging @cpojer in case he had some reason for interpreting 1 as null and I'm missing an obscure IE bug that is not showing with the current specs (does an @ mention actually ping the user? :) )

relevant commit that introduced this regression: https://github.com/mootools/mootools-core/commit/041141377eb41960a58f18094cf17f41be1cd347