Documents never have their node document set?

[jyasskin]

Sorry if I'm just failing at reading the specification, but I couldn't find where a document node's node document is initialized. Neither new Document() nor createHTMLDocument() mention it.

This would normally be an odd thing to want, since the document's node document is always itself, but we're traversing that edge when we want to get the node navigable of a Document, like in https://html.spec.whatwg.org/#doc-container-document.

[annevk]

I think you are correct. I'd suggest adding a paragraph below https://dom.spec.whatwg.org/#concept-document:

A document's node document is itself.