anchor-scope is specified to limit the exposure of anchors to not go above the anchor-scope element. However, anchor-name are also tree scoped which means that an element that is exposed as a part and given an anchor-name that way is scoped to the tree scope of the stylesheet that gives it a name (outside of the shadow dom).

I wanted to clarify what happens if both of these features are in effect:

<style>
my-element::part(anchor) {
  anchor-name: --anchor;
}
</style>
<my-element>
  <template shadowrootmode="open">
    <div id="scoper" style="anchor-scope: all">
       <div id="anchor" part="anchor"></div>
    </div>
  </template>
</my-element>

Here the #scoper element is scoping all the anchors to its subtree, but #anchor is exposed as a part and is styled in the outer tree scope and is given an anchor-name there. Is that a valid anchor in the outer (or inner) tree scope?

/cc @andruud @tabatkins