[cssom-view] scrollParent shouldn't necessarily be null for the body #12723
Description
https://drafts.csswg.org/cssom-view/#dom-htmlelement-scrollparent
- If any of the following holds true, return null and terminate this algorithm:
- The element does not have an associated box.
- The element is the root element.
- The element is the body element.
- The element’s computed value of the position property is fixed and no ancestor establishes a fixed position containing block.
Sure, the root element won't be a scroll container because of overflow propagation, so removing the early return will typically result in null anyways.
However, if the root is an open shadow host, then the body could be assigned to a slot which is a scroll container. In that case I think scrollParent should be the slot, not null.
@flackr What was the point of this condition?