307197 2026-02-06 13:40:33 -0800 NavigationEvent#canIntercept is true when navigating to a different port 2026-02-26 14:56:12 -0800 1 1 1 Unclassified WebKit Page Loading Safari 26 Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 1 christiedom ahmad.saleem792 ahmad.saleem792 basuke beidson cdumez rupin webkit-bug-importer oldest_to_newest 2178906 0 478272 christiedom 2026-02-06 13:40:33 -0800 Created attachment 478272 A file that spins up 2 node servers: one at port 3000 and the other at 3001. NavigationEvent#canIntercept is logged in the browser console [The spec](https://html.spec.whatwg.org/multipage/nav-history-apis.html#dom-navigateevent-canintercept-dev) states: > Generally speaking, this will be true whenever the current Document can have its URL rewritten to the destination URL, except for in the case of cross-document "traverse" navigations, where it will always be false. and [defining when a document have have it's URL rewritten](https://html.spec.whatwg.org/multipage/nav-history-apis.html#can-have-its-url-rewritten): > A Document document can have its URL rewritten to a URL targetURL if the following algorithm returns true: > … > If targetURL and documentURL differ in their scheme, username, password, host, or port components, then return false. In my tests, when navigating from localhost:3000 to localhost:3001, `navigattionEvent.canIntercept` returns `true`. 2178951 1 ahmad.saleem792 2026-02-06 15:47:32 -0800 Navigation::DispatchResult Navigation::innerDispatchNavigateEvent has: bool canIntercept = documentCanHaveURLRewritten(*document, destination->url()) && (!isTraversal || isSameDocument); Which is coming from here: static bool documentCanHaveURLRewritten(const Document& document, const URL& targetURL) { const URL& documentURL = document.url(); Ref documentOrigin = document.securityOrigin(); auto targetOrigin = SecurityOrigin::create(targetURL); bool isSameSite = documentOrigin->isSameSiteAs(targetOrigin); bool isSameOrigin = documentOrigin->isSameOriginAs(targetOrigin); // For cross-window navigation with document.domain, we need to check same-origin rather than same-site // to account for document.domain modifications that make cross-origin windows same-origin-domain if (!isSameSite && !isSameOrigin) return false; if (targetURL.protocolIsInHTTPFamily()) return true; if (targetURL.protocolIsFile() && !isEqualIgnoringQueryAndFragments(documentURL, targetURL)) return false; return equalIgnoringFragmentIdentifier(documentURL, targetURL); } ^ We don't check this bit here - > If targetURL and documentURL differ in their scheme, username, password, host, or port components, then return false. So something like this might fix it: ``` if (documentURL.protocol() != targetURL.protocol() || documentURL.user() != targetURL.user() || documentURL.password() != targetURL.password() || documentURL.host() != targetURL.host() || documentURL.port() != targetURL.port()) return false; ``` I tested above on WPT but WPT does not seems to have coverage. 2178980 2 webkit-bug-importer 2026-02-06 18:25:23 -0800 <rdar://problem/169845691> 2178982 3 ahmad.saleem792 2026-02-06 18:29:52 -0800 Pull request: https://github.com/WebKit/WebKit/pull/58094 2180489 4 ews-feeder 2026-02-11 15:47:43 -0800 Committed 307316@main (850ce3163e55): <https://commits.webkit.org/307316@main> Reviewed commits have been landed. Closing PR #58094 and removing active labels. 2185350 5 ahmad.saleem792 2026-02-26 14:56:12 -0800 @Dom - this change is in STP 238 - can you test and confirm, if it has resolved your issue? 478272 2026-02-06 13:40:33 -0800 2026-02-06 13:40:33 -0800 A file that spins up 2 node servers: one at port 3000 and the other at 3001. NavigationEvent#canIntercept is logged in the browser console servers.js application/x-javascript 882 christiedom Y29uc3QgaHR0cCA9IHJlcXVpcmUoImh0dHAiKTsKCmNvbnN0IHBhZ2UgPSAobmFtZSwgcG9ydCwg b3RoZXJQb3J0KSA9PiBgPCFET0NUWVBFIGh0bWw+CjxodG1sIGxhbmc9ImVuIj4KPGhlYWQ+CiAg PG1ldGEgY2hhcnNldD0iVVRGLTgiPgogIDx0aXRsZT4ke25hbWV9IChQb3J0ICR7cG9ydH0pPC90 aXRsZT4KICA8c2NyaXB0PgogICAgbmF2aWdhdGlvbi5hZGRFdmVudExpc3RlbmVyKCJuYXZpZ2F0 ZSIsIChldmVudCkgPT57CiAgICAgIGNvbnNvbGUubG9nKGV2ZW50LmNhbkludGVyY2VwdCk7CiAg ICB9KTsKICA8L3NjcmlwdD4KPC9oZWFkPgo8Ym9keT4KICA8aDE+JHtuYW1lfTwvaDE+CiAgPHA+ UnVubmluZyBvbiBwb3J0ICR7cG9ydH08L3A+CiAgPGEgaHJlZj0iaHR0cDovL2xvY2FsaG9zdDok e290aGVyUG9ydH0iPkdvIHRvIHBvcnQgJHtvdGhlclBvcnR9PC9hPgo8L2JvZHk+CjwvaHRtbD5g OwoKaHR0cC5jcmVhdGVTZXJ2ZXIoKHJlcSwgcmVzKSA9PiB7CiAgcmVzLndyaXRlSGVhZCgyMDAs IHsgIkNvbnRlbnQtVHlwZSI6ICJ0ZXh0L2h0bWwiIH0pOwogIHJlcy5lbmQocGFnZSgiU2VydmVy IEEiLCAzMDAwLCAzMDAxKSk7Cn0pLmxpc3RlbigzMDAwLCAoKSA9PiBjb25zb2xlLmxvZygiU2Vy dmVyIEEgcnVubmluZyBhdCBodHRwOi8vbG9jYWxob3N0OjMwMDAiKSk7CgpodHRwLmNyZWF0ZVNl cnZlcigocmVxLCByZXMpID0+IHsKICByZXMud3JpdGVIZWFkKDIwMCwgeyAiQ29udGVudC1UeXBl IjogInRleHQvaHRtbCIgfSk7CiAgcmVzLmVuZChwYWdlKCJTZXJ2ZXIgQiIsIDMwMDEsIDMwMDAp KTsKfSkubGlzdGVuKDMwMDEsICgpID0+IGNvbnNvbGUubG9nKCJTZXJ2ZXIgQiBydW5uaW5nIGF0 IGh0dHA6Ly9sb2NhbGhvc3Q6MzAwMSIpKTsK