Error message when removing coupon

-- url of the page with the problem -- : local
-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.4.1
-- PHP version -- : 5.5.3
-- Browser(s) name and version -- : any
-- Error-message(debug-mod must be tuned on) -- : JGLOBAL_AUTH_EMPTY_PASS_NOT_ALLOWED

Hi,

Not a big issue, but I found some oddity when removing a coupon in checkout and thought I'll let you know.

Conditions:
• Registration or simplified registration with password is selected.
• Login/registration and coupon on the same checkout page.
• Guest tries to remove (auto-loaded) coupon before having logged in or registered.
• Any template incl Protostar.

Result until 2.4.0:
• System alert:

• Auto-loaded coupon remains in place = is not being removed.

Result in 2.5.0:
• System alert:• Auto-loaded coupon remains in place = is not being removed.

I sort of understand that an auto-loaded coupon does not get removed. But then there shouldn't be the success message "Coupon removed". And certainly not twice.

is present in both en-GB.ini (admin and frontend), but shows up since 2.5.0 as untranslated language constant - why?
I would understand if it shows up (translated!) upon finishing the checkout before entering a password - but that's practically impossible due to the "finish" button not being there. But why does it show up in connection with the coupon?
Sure, I see it's new in /components/com_hikashop/controllers/checkout.php, but maybe it still needs some work. As it's now, it's all too confusing for customers...

There's no head-scratching smiley. So, imagine me scratching my head. And one more