[whatwg/fetch] Reinvestigate redirects to data URLs (#393)

I managed to flip on this several times in the course of #111, the last time due to investigations in how navigate works in #309. I think my mistake might have been that I did not investigate "no-cors", as redirects to data URLs still work there in (some) implementations and lead to the response being treated as CORS-cross-origin (HTML's term).

Related tests that might need updating:
* https://github.com/w3c/web-platform-tests/pull/3095
* https://github.com/w3c/web-platform-tests/pull/3644

Thanks to @youennf for finding this.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/fetch/issues/393