"look up a custom element registry" can be called with a DocumentFragment node

[AtkinsSJ]

What is the issue with the HTML Standard?

"Look up a custom element registry" handles Elements, ShadowRoots, and Documents. But it can be called with a DocumentFragment. Specifically I'm seeing "create an element for the token" doing so, at step 6:

Let registry be the result of looking up a custom element registry given intended parent.

"Intended parent" here is a DocumentFragment, at least in some cases. (I haven't done an exhaustive search, I'm just getting crashes because of it. 😅) This doesn't have a custom element registry.

@annevk

[AtkinsSJ]

It seems like the fix is as simple as:

3. If node is a Document object, then return node's custom element registry.
4. Return null.

[annevk]

Thanks! The signature also has to change.

[annevk]

Actually, when would this be a DocumentFragment? I thought the HTML parser always operated on a Document.

[AtkinsSJ]

IIRC, when parsing it uses a DocumentFragment as the parent, and then moves all its children into their actual location in the document.

[annevk]

Ah, I guess this can happen with a template element. And in that case we indeed want to use null so that seems correct.