According to the fetch specification: "A redirect status is a status that is 301, 302, 303, 307, or 308.", i.e., all other status codes should not redirect. (https://fetch.spec.whatwg.org/#statuses) WebKit redirect for many other status codes such as 305, 306, 309. Test: https://echo.sectec.rocks/echo/?location=https://example.org&ecohd_status=305
I am able to reproduce this in Safari / WebKit ToT, where the URL redirects to example.com while Chrome Canary 118 and Firefox Nightly 118 does not redirect. Adding 'BrowserCompat' because both other browsers are matching each other and WebKit is behaving different.
<rdar://problem/115264053>
Confirmed.
This can't be solved on the WebKit Project but this will be taken care of in the Radar.
Jannis, Thanks a lot if you have more like these, do not hesitate to report them. Super appreciated.