Discount coupon value

[pilou2]

On ZC v2.0.0-rc2, discount coupons are displayed /calculated wrong values in checkout pages.
There is a unique tax class with rate of 10%.
There are two items in cart, one at $48.34 and the other at $35.00 gross price.
Flat rate shipping ($5) is used as shipping method and is set to same tax class as items (10%).
'ot_coupon' settings are default.

Coupon value is wrong when displaying prices with tax (orange color), which makes although tax and total wrong. But tax and total calculations appear to be good.
In table below, 'ZC' column is what is displayed in ZC v2.0.0-rc2, 'Good' column is what I think it should be and just for information and to identify lost penny, I included a 'no rounding' column. There is actually a penny loss in tax calculation when displaying prices with tax.

My understanding of discount coupons is that the discount should be applied to final total ($97.17 including tax) to get the new total and that tax should be re-calculate to fit this new total.