[csswg-drafts] [css-contain-1] maybe 'contain-size' shouldn't apply to display:table-caption?

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

== [css-contain-1] maybe 'contain-size' shouldn't apply to display:table-caption? ==
The [definition of `contain:size`](https://drafts.csswg.org/css-contain/#containment-size) says that `contain:size` doesn't have an effect on `table` or on internal table elements.  This means it doesn't apply to `display:table-cell`... but it does apply to `display:table-caption`, which [isn't defined as an internal table element](https://drafts.csswg.org/css-display-3/#internal-table-element) (to my surprise, and in disagreement with Gecko's code).

I don't have a strong opinion here... and I just filed [Mozilla bug 1478850](https://bugzilla.mozilla.org/show_bug.cgi?id=1478550)... but it's possible the spec should change here?

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/2952 using your GitHub account