IntersectionObserver spec needs to be clearer about "overflow clip" / "overflow clipping" terminology

[dholbert]

The IntersectionObserver spec uses the term "overflow clip" twice:
Section 2.2 says:

If the intersection root has an overflow clip

Section 3.2.4 says:

If container has overflow clipping

This terminology isn't precise enough.

Does it mean literally overflow:clip?

Or does it also mean overflow:hidden (which isn't named "clip" but whose spec text says the "content is clipped")

Or does it mean overflow: [non-visible] (since e.g. scroll also says "the content is clipped")? Or something else? Please clarify the terminology and ideally link to a definition if possible -- thanks!

[a2sheppy]

Watching this so I can update documentation, as I'm trying to fill in a gap in the docs on MDN where we don't really cover how clipping is handled by IO.

[dholbert]

It looks like no browser currently supports overflow:clip (per footnote 2 on https://caniuse.com/#search=overflow ), so that's probably not what the spec means here.

So I'm guessing the spec is using "overflow clip" to mean overflow: [non-visible]. (Though it's quite easy to misread "overflow clip[ping]" as overflow:clip, so definitely worth clarifying.)

[wangxianzhu]

The original comment has been moved into #518.

[wangxianzhu]

The original comment has been moved into #518.

[wangxianzhu]

The current spec (https://www.w3.org/TR/intersection-observer/) no longer mentions "overflow clip" / "overflow clipping". Should we close this issue?

@szager-chromium