[csswg-drafts] [css-contain-2] Spec is unclear about whether 0-sized boxes can be "relevant to the user" (since they have zero intersection area) (#5641)

dholbert has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-contain-2] Spec is unclear about whether 0-sized boxes can be "relevant to the user" (since they have zero intersection area) ==
The "relevant to the user" ( https://www.w3.org/TR/css-contain-2/#relevant-to-the-user ) condition is defined as-follows:
> An element is relevant to the user if any of the following conditions are true:
>    The element is "on-screen": its containing box's border box intersects with the viewport, or a user-agent defined margin around the viewport.

This definition is ambiguous about whether or not a on-screen 0-sized box would be considered relevant or not.  Such a box has 0 area, and hence it would have zero intersection, even if it's positioned on-screen.  So it arguably never "intersects with the viewport", even when it is fully contained within the viewport.

It would be nice for the spec to make clear what happens for such boxes.  Possibly just adding a sentence saying "For the purpose of this consideration, a 0-sized box *is* considered as intersecting this area if it is fully contained within this area."

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/5641 using your GitHub account


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Received on Tuesday, 20 October 2020 20:00:45 UTC