Specials not adding correct

[Guest]

Hi

When I try to add a special for a product that have different prices for different sizes,

the specials dont calculate the special for the extra price.

 

Does anyone have a fix for this.

 

example

 

price: 1000 normal size 10% discount = 900 as special price.

Price 1000 for normal + 100 for extra size =1000 as special price but it should have been 990