222733 2021-03-04 05:04:55 -0800 The :host() function pseudo-class should only accept a single compound-selector 2023-08-07 15:29:23 -0700 1 1 1 Unclassified WebKit CSS Safari 13 Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 148695 1 andruud rniwa emilio koivisto nlawson rniwa webkit-bug-importer oldest_to_newest 1735785 0 andruud 2021-03-04 05:04:55 -0800 It appears that Webkit currently accepts a <compound-selector-list> parse-time (but then it doesn't fully work at selector-matching-time)? In any case, the correct grammar is now: :host( <compound-selector> ) https://drafts.csswg.org/css-scoping/#selectordef-host Test: <!DOCTYPE html> <template id=template> <style> :host(#host1) slot { color: green; } :host(#host2, #host3) slot { color: green; } </style> <slot></slot> </template> <div id=host1><span>Should be green</span></div> <div id=host2><span>Should not be green</span></div> <div id=host3><span>Should not be green</span></div> <script> host1.attachShadow({mode:'open'}).append(template.content.cloneNode(true)); host2.attachShadow({mode:'open'}).append(template.content.cloneNode(true)); host3.attachShadow({mode:'open'}).append(template.content.cloneNode(true)); </script> 1738423 1 webkit-bug-importer 2021-03-11 05:05:15 -0800 <rdar://problem/75311716> 1880436 2 rniwa 2022-07-03 16:31:08 -0700 Pull request: https://github.com/WebKit/WebKit/pull/2045 1880469 3 ews-feeder 2022-07-03 22:29:48 -0700 Committed 252110@main (e91f2366aef4): <https://commits.webkit.org/252110@main> Reviewed commits have been landed. Closing PR #2045 and removing active labels. 1969980 4 ntim 2023-08-07 15:29:23 -0700 *** Bug 249420 has been marked as a duplicate of this bug. ***