[csswg-drafts] [css-values] attr()'s url type seems wrong (#5079)

annevk has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-values] attr()'s url type seems wrong ==
Per https://drafts.csswg.org/css-values-4/#attr-types the value of the attribute is literally forwarded to CSS, without taking into account how that attribute would be parsed (which requires passing in a base URL and encoding to the URL parser). This means that if you have

> `foo="bar"`

in your document at `/` and your CSS is in `/css/meh` it'll link to `/bar` in your document and `/css/bar` in your CSS.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/5079 using your GitHub account