https://wpt.fyi/results/css/css-fonts/variations/font-shorthand.html?label=master&label=experimental&aligned&view=subtest&q=firefox%3Apass%20chrome%3Apass%20safari%3A%21pass https://github.com/web-platform-tests/wpt/blob/45fd19926d0c278bad060478674b23c27fd77d4b/css/css-fonts/variations/font-shorthand.html#L31-L32 Seems like font-style already correctly rejects them, but not the font shorthand.
<rdar://problem/101437235>
Pull request: https://github.com/WebKit/WebKit/pull/5651
Committed 255871@main (773a9ae47bff): <https://commits.webkit.org/255871@main> Reviewed commits have been landed. Closing PR #5651 and removing active labels.