[css-variables] Relative URL resolution in var() references #757
Description
Related discussions:
https://twitter.com/LeaVerou/status/801661659949371392
https://bugs.chromium.org/p/chromium/issues/detail?id=618165
Summary: Relative URL resolution in var() is underspecified and currently buggy in all browsers.
The main issue is, as @tabatkins pointed out in the second linked thread above is this:
/* a.css */
--a: "a.png";
/* b.css */
--b: url(var(--a));
/* c.css */
background-image: var(--b); /* resolved according to a, b, or c? */Since CSS Variables are uninterpreted token streams, it should be c (which is what @dbaron and I think), but some members (such as @FremyCompany in the first thread) argue that this may not be useful to authors.