CSS loader not extracting path in -webkit-image-set

[lemieux]

Hi,

we currently use this mixin in our LESS code to generate retina display background images

.retina-image(@width, @height, @normal-image, @retina-image) {
  width: @width;
  height: @height;
  background-image: url(@normal-image); // fallback for Firefox and IE
  background-image: -webkit-image-set(
    url(@normal-image) 1x,
    url(@retina-image) 2x
  );
  background-repeat: no-repeat;
  display: inline-block;
}

and it seems like the url in background-image: url(@normal-image); is picked up and replaced by the loader but not the ones in -webkit-image-set. They are just rendered as -webkit-image-set(url('/path/to/image') 1x, url('/path/to/image@2x')).