Ranger Attack Speed 'Doubled' Bug

It appears that Rangers attack speed isn't actually being 'doubled' right now. Instead It's adding 0.7 * 0.7 to their attack speed. So Rangers start with 0.7 attack speed, then when 'doubled' they have 1.19 attack speed ( 0.7 * 0.7 + 0.7). Essentially instead of actually doubling their attack speed Rangers are getting 70% attack speed increase.

See linked image for Vayne with the 'doubled' attack speed.