As demonstrated in :
Setting the opacity to null does not remove the opacity style. Arian says it has something to do with the value being parsed with parseFloat.
Specs for #2266 and rudimentary fix.
@ibolmo any ideas?
this test fails: arian@b3e80ee#L1R44
The idea is: create an element where CSS is applied by a CSS class. So getStyle('opacity') should return 0.5 if the filter has alpha(opacity=50).
However when you set the opacity to 1, and then set it to null, it should return 0.5 again, but it doesn't.
As far as I can see, if element.style.filter was set once, it isn't removed, but is set to filter: ; zoom: 1, so it doesn't fall back to the defined CSS.
filter: ; zoom: 1
ah, we should be using element.style.removeAttribute('filter'); when the filter property is empty.