Pass restrictions to arguments of any functional pseudo-class

The specification wants all logical pseudo-classes to pass restrictions at their
position to their arguments.

This commit extends this requirement to any functional pseudo-class.

In fact, this already applied when they were compounded to a pseudo-element and
they took a complex selector or a pseudo-class that cannot be compounded to this
pseudo-element.

w3c/csswg-drafts#12718

Author: cdoublev

__tests__/value.js

@@ -4409,6 +4409,10 @@ describe('<selector-list>', () => {
             ':host(:not(:has(type)))',
             ':host-context(:not(type > type))',
             ':host-context(:not(:has(type)))',
+            '::part(name):current(:only-child)',
+            '::part(name):current(type)',
+            '::part(name):not(:current(:only-child))',
+            '::part(name):not(:current(type))',
             '::slotted(:not(type > type))',
             '::slotted(:not(:has(type)))',
             // Invalid sub-pseudo-element

lib/parse/preprocess.js

@@ -191,20 +191,21 @@ function preParseComplexSelectorUnit(node) {
  * when the combinator is omitted and there is no interleaving whitespace.
  *
  * It aborts parsing when the next token is not a pseudo whereas the context is
- * a logical pseudo-class compounded to a pseudo-element.
+ * a functional pseudo-class compounded to a pseudo-element.
  */
 function preParseCompoundSelector(node) {
     if (hasInvalidSiblingCombinator(node)) {
         return null
     }
     if (
         !node.input.peek(isColon)
-        && findFunction(node, node =>
-            pseudos.logical[node.definition.name]
-            && findParent(
-                node,
-                node => node.parent?.definition.name === '<pseudo-compound-selector>',
-                node => node.definition.name === '<subclass-selector>'))
+        && findFunction(node, node => {
+            const compound = findParent(node, node => node.parent?.definition.name === '<pseudo-compound-selector>')
+            if (compound) {
+                return 0 < compound.children.length
+            }
+            return false
+        })
     ) {
         return error(node)
     }