[css-variables] Animation tainting text doesn't cover the cases where a property references a tainted property

[FremyCompany]

I don't think the text in the spec covers this example:

div { 
	animation: anim 1s infinite alternate; 
	--var: block; --var2: var(--var);
}

div::after {
	content: "abc";
	display: var(--var2);
}

@keyframes anim {
	to { --var: none; }
}

https://drafts.csswg.org/css-variables/#substitute-a-var

If the custom property named by the first argument to the var() function is animation-tainted [... ignore it in display if it resolves to none ...]

any custom property used in a @keyframes rule becomes animation-tainted, which affects how it is treated when referred to via the var() function in an animation property.

var2 is never used in a keyframes rules so should not be animation tainted

[tabatkins]

Agreed, animation-taint definitely needs to be infectious.