292968 2025-05-13 18:22:38 -0700 REGRESSION (Safari 18.4): Declarative shadow DOM and custom elements do not work with parseUnsafeHTML 2025-05-16 21:53:28 -0700 1 1 1 Unclassified WebKit DOM WebKit Nightly Build All All RESOLVED FIXED InRadar P2 Normal --- 1 mic.gallego rniwa ahmad.saleem792 cdumez rniwa webkit-bug-importer oldest_to_newest 2116934 0 mic.gallego 2025-05-13 18:22:38 -0700 Hello, On Safari exclusively (it works on Chrome), parseUnsafeHTML and setUnsafeHTML are not working with nested web components. Even though the web components are inserted into the page, the `connectedCallback` is never called. You can experience the issue here: https://codepen.io/bakura10/pen/LEEqGmy On Chrome, both messages are logged. On Safari, the nested web components is not initialized at all. Thanks. 2116936 1 mic.gallego 2025-05-13 18:36:18 -0700 After further testing, it appears to work on Safari 18.1, but not on 18.3 and 18.4. It therefore seems to be a recent regression. 2116940 2 ahmad.saleem792 2025-05-13 19:00:17 -0700 *** 2116941 3 webkit-bug-importer 2025-05-13 19:00:26 -0700 <rdar://problem/151273154> 2116942 4 ahmad.saleem792 2025-05-13 19:02:22 -0700 *** Safari Technology Preview 218 *** "Bar: Should be called" *** Chrome Canary 138.0.7177.0 (Official Build) canary (arm64) *** "Bar: Should be called" "Bim: Should be called" *** Firefox Nightly 140 (20250513214736) *** "Bar: Should be called" "Bim: Should be called" 2117178 5 ap 2025-05-14 15:18:17 -0700 Thank you for the report! Between 18.2 and 18.3, guessing the former because it was a release with more changes overall. 2117179 6 ap 2025-05-14 15:19:59 -0700 Actually, looks like our testing so far disagrees, and 18.3 worked. 2117761 7 475277 rniwa 2025-05-16 15:49:44 -0700 Created attachment 475277 Reduction 2117815 8 rniwa 2025-05-16 17:00:07 -0700 Pull request: https://github.com/WebKit/WebKit/pull/45526 2117847 9 ews-feeder 2025-05-16 21:53:26 -0700 Committed 295050@main (6d35fd51666a): <https://commits.webkit.org/295050@main> Reviewed commits have been landed. Closing PR #45526 and removing active labels. 475277 2025-05-16 15:49:44 -0700 2025-05-16 15:49:44 -0700 Reduction connected-callback.html text/html 597 rniwa PCFET0NUWVBFIGh0bWw+Cjxib2R5Pgo8c2NyaXB0Pgp3aW5kb3cuY3VzdG9tRWxlbWVudHMuZGVm aW5lKCdpbm5lci1lbGVtZW50JywgY2xhc3MgZXh0ZW5kcyBIVE1MRWxlbWVudCB7CiAgICBjb25u ZWN0ZWRDYWxsYmFjaygpIHsgcmVzdWx0LnRleHRDb250ZW50ID0gJ1BBU1MnOyB9Cn0pOwo8L3Nj cmlwdD4KPHA+VGhpcyB0ZXN0cyB1c2luZyA8Y29kZT5wYXJzZUhUTUxVbnNhZmU8L2NvZGU+IHRv IGNyZWF0ZSBhIGRlY2xhcmF0aXZlIHNoYWRvdyBET00uPGJyPgpjb25uZWN0ZWRDYWxsYmFjayBz aG91bGQgYmUgY2FsbGVkIG9uIGEgY3VzdG9tIGVsZW1lbnQgaW5zaWRlIHRoZSBzaGFkb3cgRE9N LjwvcD4KPGRpdiBpZD0icmVzdWx0Ij5GQUlMPC9kaXY+CjxkaXYgaWQ9ImNvbnRhaW5lciI+PC9k aXY+CjxzY3JpcHQ+CmNvbnRhaW5lci5hcHBlbmQoLi4uRG9jdW1lbnQucGFyc2VIVE1MVW5zYWZl KCc8b3V0ZXItZWxlbWVudD48dGVtcGxhdGUgc2hhZG93cm9vdG1vZGU9Im9wZW4iPjxpbm5lci1l bGVtZW50PjwvaW5uZXItZWxlbWVudD48L3RlbXBsYXRlPjwvb3V0ZXItZWxlbWVudD4nKS5jaGls ZE5vZGVzKTsKPC9zY3JpcHQ+CjwvYm9keT4K