[csswg-drafts] [css-scoping] [selectors] <compound-selector-list> should somehow affect :is() / :where() parsing (#5093)

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

== [css-scoping] [selectors] <compound-selector-list> should somehow affect :is() / :where() parsing ==
https://drafts.csswg.org/css-scoping/#host-selector takes a `<compound-selector-list>` (that is, doesn't accept combinators). This is good, as otherwise it'd break the shadow tree encapsulation.

However strictly per the syntax technically something like `:host(:is(div div))` should parse. I think this is a spec bug.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/5093 using your GitHub account