HTMLDialogElement::showModal() should fail on popovers, same for Element::requestFullscreen().
Actually it shouldn't fail, those 2 methods should just run the "hide all popovers" algorithm
<rdar://problem/105763866>
So there are 2 items: - run "hide all popovers" when showing - Forbid elements in popover showing state from being modal/fullscreen
Pull request: https://github.com/WebKit/WebKit/pull/11155
Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/38844
Committed 261317@main (ffc70a735c9b): <https://commits.webkit.org/261317@main> Reviewed commits have been landed. Closing PR #11155 and removing active labels.
*** Bug 255232 has been marked as a duplicate of this bug. ***