307878 2026-02-13 18:08:41 -0800 Calling upgrade on a candidate with a different registry erroneously upgrades the element 2026-03-09 23:35:16 -0700 1 1 1 Unclassified WebKit DOM Safari Technology Preview Mac (Apple Silicon) macOS 26 RESOLVED FIXED InRadar P2 Normal --- 154907 1 steveorvell rniwa rniwa webkit-bug-importer oldest_to_newest 2181611 0 478345 steveorvell 2026-02-13 18:08:41 -0800 Created attachment 478345 Unexpected custom element customization See the attached reproduction. When `registry2.upgrade` is called on an un-upgraded element defined in a different registry, the element unexpectedly upgrades. 2183598 1 webkit-bug-importer 2026-02-20 18:09:11 -0800 <rdar://problem/170846743> 2188567 2 rniwa 2026-03-09 19:19:05 -0700 Pull request: https://github.com/WebKit/WebKit/pull/60239 2188618 3 ews-feeder 2026-03-09 23:35:14 -0700 Committed 308962@main (ca90cbd6ebfb): <https://commits.webkit.org/308962@main> Reviewed commits have been landed. Closing PR #60239 and removing active labels. 478345 2026-02-13 18:08:41 -0800 2026-02-13 18:08:41 -0800 Unexpected custom element customization unexpected-upgrade.html text/html 878 steveorvell PHNjcmlwdD4KICBjb25zb2xlLmNsZWFyKCk7CiAgY29uc3QgcmVnaXN0cnkxID0gbmV3IEN1c3Rv bUVsZW1lbnRSZWdpc3RyeSgpOwogIGNvbnN0IHJlZ2lzdHJ5MiA9IG5ldyBDdXN0b21FbGVtZW50 UmVnaXN0cnkoKTsKCiAgY29uc3QgeEZvbyA9IGRvY3VtZW50LmNyZWF0ZUVsZW1lbnQoJ3gtZm9v Jywge2N1c3RvbUVsZW1lbnRSZWdpc3RyeTogcmVnaXN0cnkxfSk7CiAgcmVnaXN0cnkxLmRlZmlu ZSgneC1mb28nLCBjbGFzcyBleHRlbmRzIEhUTUxFbGVtZW50IHt9KTsKICBsZXQgdW5EZWZpbmVk ID0geEZvby5tYXRjaGVzKCc6bm90KDpkZWZpbmVkKScpOwogIGNvbnNvbGUuYXNzZXJ0KHVuRGVm aW5lZCwgJ3VuZXhwZWN0ZWQgdXBncmFkZSBhZnRlciBiZWluZyBkZWZpbmVkIGJ1dCBub3QgaW4g ZG9jdW1lbnQnKTsKICBpZiAodW5EZWZpbmVkKSB7CiAgICByZWdpc3RyeTIudXBncmFkZSh4Rm9v KTsKICAgIHVuRGVmaW5lZCA9IHhGb28ubWF0Y2hlcygnOm5vdCg6ZGVmaW5lZCknKTsKICAgIGNv bnNvbGUuYXNzZXJ0KHVuRGVmaW5lZCwgJ3VuZXhwZWN0ZWQgdXBncmFkZSBhZnRlciBiZWluZyB1 cGdyYWRlZCBpbiBhIG5vbi1tYXRjaGluZyBzY29wZWQgcmVnaXN0cnknKQogIH0KICBpZiAodW5E ZWZpbmVkKSB7CiAgICBjdXN0b21FbGVtZW50cy51cGdyYWRlKHhGb28pOwogICAgdW5EZWZpbmVk ID0geEZvby5tYXRjaGVzKCc6bm90KDpkZWZpbmVkKScpOwogICAgY29uc29sZS5hc3NlcnQodW5E ZWZpbmVkLCAndW5leHBlY3RlZCB1cGdyYWRlIGFmdGVyIGJlaW5nIHVwZ3JhZGVkIGluIGEgbm9u LW1hdGNoaW5nIGdsb2JhbCByZWdpc3RyeScpOwogIH0KICBjb25zb2xlLmxvZygnZmFpbGVkIGFz c2VydHMgYWJvdmUnKQo8L3NjcmlwdD4=