Intersection Meta fails for multiple nodes

[smhigley]

Bug

Intersection Meta will always return the default intersection for all but the first node observed by a root element. Lines 56-60 currently check if any observer at all exists on the root node, and only calls .observe(node) if not:

let details = this._getDetails(options);
if (!details) {
    details = this._createDetails(options, rootNode);
    details.observer.observe(node);
}

I believe this would be fixed with:

let details = this._getDetails(options);
if (!details || !details.entries.get(node)) {
    details = this._createDetails(options, rootNode);
    details.observer.observe(node);
}