1.5, thumbnails regenerate by height not working if height of initial image is too small

[louissss]

Hi

 

I am using Prestashop 1.5. When I "regenerate" large_default thumbnails  by Height.

 

If the original picture's height is greater than the large_default's height (set in backoffice), everything is ok.

But if the original picture's height is smaller than the large_default's height (set in backoffice), the large_default thumbnail is not regenerated by Height but by "Auto".

 

I would like to change this behavior, and force prestashop generate an image that is the height that I set-up for large-default.

 

Is it possible ?

 

Thanks