[css-variables][css-conditional] bad-string and bad-url tokens in non-custom properties that reference variables #3170
Description
from https://lists.w3.org/Archives/Public/www-style/2013Aug/0525.html by @heycam
<bad-string> and <bad-url> tokens are disallowed in <any-value>, which
is used as the value for custom properties and also as the fallback for
variable references. But they are not disallowed at the top level of a
non-custom property that has variable references (and thus invokes the
"property value containing a variable must be assumed to be valid at
parse time" requirement). So:
@supports (color: var(a, "
)) { ... fails ... }
@supports (color: var(a, url("b" c)) { ... fails ... }
@supports (var-a: "
) { ... fails ... }
@supports (var-a: url("b" c)) { ... fails ... }
But:
@supports (color: var(a) "
) { ... succeeds ... }
@supports (color: var(a) url("b" c)) { ... succeeds ... }
Should we make these fail too?