281131 2024-10-09 03:18:03 -0700 Immediate crash when WebComponents are combined with global styles & container queries. 2026-04-25 17:21:20 -0700 1 1 1 Unclassified WebKit CSS Safari Technology Preview All iOS 18 RESOLVED CONFIGURATION CHANGED https://bugs.webkit.org/show_bug.cgi?id=292247 InRadar P2 Normal --- 148695 1 marco webkit-unassigned koivisto nicole rniwa simon.fraser webkit-bug-importer woodlxf00 oldest_to_newest 2066462 0 472875 marco 2024-10-09 03:18:03 -0700 Created attachment 472875 Crash Sample Component The following issue occurs with Safari 18 on all platforms, including Mac, also Technology Preview. When using container queries, I noticed a malfunction that I cannot further isolate. The combination of container queries, WebComponents, and (this is where I get stuck) the application of irrelevant CSS causes the page to crash. I have isolated a Stackblitz sample and partially narrowed down the problem. https://stackblitz.com/edit/stackblitz-starters-gxvbz9?file=index.html Steps to Reproduce: 1. Open the provided Stackblitz or sample-crash.html sample in Safari 18. 2. Ensure lines 7 to 9 are active. 3. Observe the page crash a few seconds after loading. The page crashes a few seconds after loading with no error message or indication of the cause. There is no apparent connection between the responsible CSS block and the WebComponent in the example. Additional Information: - The issue does not occur when CSS lines 14-20 are commented out. - The problem seems to be related to the interaction between container queries and WebComponents. - `.ux-button--no-border:not(:active):not(:disabled):hover ux-icon`==> crashed immediately - `.ux-button--no-border:not(:active):not(:disabled):hover > ux-icon` ==> works 2067809 1 ap 2024-10-14 12:52:50 -0700 rdar://137812974 I can reproduce this after uncommenting lines 7-9 (as per original steps to reproduce), and clicking in the content (which is not). Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 WebCore 0x11a38a380 WebCore::Style::Update::elementStyle(WebCore::Element const&) + 0 1 WebCore 0x11a32ddd8 WebCore::Style::ContainerQueryEvaluator::selectContainer(WTF::OptionSet<WebCore::CQ::Axis>, WTF::String const&, WebCore::Element const&, WebCore::Style::ContainerQueryEvaluator::SelectionMode, WebCore::Style::ScopeOrdinal, WebCore::Style::ContainerQueryEvaluationState const*)::$_0::operator()(WebCore::Element const&, WebCore::Element const*) const + 120 2 WebCore 0x11a32db90 WebCore::Style::ContainerQueryEvaluator::selectContainer(WTF::OptionSet<WebCore::CQ::Axis>, WTF::String const&, WebCore::Element const&, WebCore::Style::ContainerQueryEvaluator::SelectionMode, WebCore::Style::ScopeOrdinal, WebCore::Style::ContainerQueryEvaluationState const*) + 464 3 WebCore 0x11a335a44 WebCore::Style::ElementRuleCollector::containerQueriesMatch(WebCore::Style::RuleData const&, WebCore::Style::MatchRequest const&) + 392 4 WebCore 0x11a3332c0 WebCore::Style::ElementRuleCollector::collectMatchingRulesForList(WTF::Vector<WebCore::Style::RuleData, 1ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc> const*, WebCore::Style::MatchRequest const&) + 1944 2114258 2 ap 2025-04-30 10:55:01 -0700 I can still reproduce this with macOS Sequoia 15.5 beta. 2204503 3 rniwa 2026-04-25 17:21:03 -0700 Hm... I can't reproduce this crash on Safari 26.4. 472875 2024-10-09 03:18:03 -0700 2024-10-09 03:18:03 -0700 Crash Sample Component sample-crash.html text/html 1042 marco PCFET0NUWVBFIGh0bWw+DQo8aHRtbCBsYW5nPSJlbiI+DQogIDxoZWFkPg0KICAgIDxtZXRhIGNo YXJzZXQ9IlVURi04IiAvPg0KICAgIDxtZXRhIG5hbWU9InZpZXdwb3J0IiBjb250ZW50PSJ3aWR0 aD1kZXZpY2Utd2lkdGgsIGluaXRpYWwtc2NhbGU9MS4wIiAvPg0KICAgIDxzdHlsZT4NCiAgICAg IC8qIC51eC1idXR0b24tLW5vLWJvcmRlcjpub3QoOmFjdGl2ZSk6bm90KDpkaXNhYmxlZCk6aG92 ZXIgdXgtaWNvbiB7DQogICAgICAgIGNvbG9yOiB2YXIoLS11eC1jb2xvci1wcmltYXJ5KTsNCiAg ICAgIH0gKi8NCiAgICA8L3N0eWxlPg0KICA8L2hlYWQ+DQoNCiAgPGJvZHk+DQogICAgPG15LWNv bXBvbmVudCB2YXJpYW50PSJzcGlubmVyIj48L215LWNvbXBvbmVudD4NCg0KICAgIDxzY3JpcHQ+ DQogICAgICBjbGFzcyBNeUNvbXBvbmVudCBleHRlbmRzIEhUTUxFbGVtZW50IHsNCiAgICAgICAg Y29uc3RydWN0b3IoKSB7DQogICAgICAgICAgc3VwZXIoKTsNCiAgICAgICAgICBjb25zdCBzaGFk b3cgPSB0aGlzLmF0dGFjaFNoYWRvdyh7IG1vZGU6ICdvcGVuJyB9KTsNCiAgICAgICAgICBjb25z dCBzdHlsZSA9IGRvY3VtZW50LmNyZWF0ZUVsZW1lbnQoJ3N0eWxlJyk7DQogICAgICAgICAgc3R5 bGUudGV4dENvbnRlbnQgPSBgDQogICAgICAgICAgICAgICAgICAgICAgICAgIEBjb250YWluZXIg c3R5bGUoLS1zb21lOiB3ZWIpIHsNCiAgICAgICAgICAgICAgICAgICAgICAgICAgICA6aG9zdCB7 DQogICAgICAgICAgICAgICAgICAgICAgICAgICAgICAtLXV4LXNwaW5uZXItdHJhY2stY29sb3I6 ICNiYmQwM2EgOw0KICAgICAgICAgICAgICAgICAgICAgICAgICAgIH0NCiAgICAgICAgICAgICAg ICAgICAgICAgICAgfQ0KICAgICAgICAgICAgICAgIGA7DQogICAgICAgICAgc2hhZG93LmFwcGVu ZENoaWxkKHN0eWxlKTsNCiAgICAgICAgfQ0KICAgICAgfQ0KICAgICAgY3VzdG9tRWxlbWVudHMu ZGVmaW5lKCdteS1jb21wb25lbnQnLCBNeUNvbXBvbmVudCk7DQogICAgPC9zY3JpcHQ+DQogIDwv Ym9keT4NCjwvaHRtbD4NCg==