[selectors4] Multiple subject indicators

Adrian Longley (CCed) just pointed out to me that the behaviour of CSS Selectors is undefined when multiple subject indicators [1] are specified. For example `!ul + !p  img`.

I guess there are two reasonable things to do here:

a) The selector is invalid and the entire rule is discarded per regular CSS rules
b) The last subject wins

(a) is kind of implied by the wording of the latest draft, but I think it should be explicitly specified.

Thoughts?

[1]: http://dev.w3.org/csswg/selectors4/#subject


Lea Verou
W3C developer relations
http://w3.org/people/all#lea ✿ http://lea.verou.me ✿ @leaverou