Riot doesn't follow 301 responses during homeserver discovery

[non-Jedi]

Description

When I enter in my mxid @adam:thebeckmeyers.xyz, Riot sends a request to https://thebeckmeyers.xyz/.well-known/matrix/client and gets back:

HTTP/2.0 301 Moved Permanently
content-length: 0
location: https://www.thebeckmeyers.xyz/.well-known/matrix/client
X-Firefox-Spdy: h2

It then fails to request the specified location and says "Invalid homeserver discovery response"

Steps to reproduce

Enter @adam:thebeckmeyers.xyz in the username field of Riot sign-in.

Version information

• Platform: web

For the web app:

• Browser: Firefox 65.0.1
• OS: Void Linux
• URL: riot.im/develop

[turt2live]

fwiw, the spec is super strict in this respect and doesn't let us follow 301 redirects: https://matrix.org/docs/spec/client_server/r0.4.0.html#server-discovery

MSC1700 could probably be brought back to life, and take this into consideration. Have opened https://github.com/matrix-org/matrix-doc/issues/1919 to track this.

[non-Jedi]

Ah. Not sure what the practice is on bugs on riot-web where a spec issue causes a Riot ux issue. Feel free to close this if that's the best way of handling.

[turt2live]

riot-web is the dumping ground for UX of Matrix, still :(

[hex-m]

MSC2499 would clarify this.

[tulir]

Element already follows redirects, but https://thebeckmeyers.xyz/.well-known/matrix/client is missing CORS headers.

[turt2live]

Overall this issue isn't one of Element (if anything it shouldn't follow the redirect), but of the spec: https://github.com/matrix-org/matrix-doc/issues/1919

Closing in favour of the spec issue. In general I think we should continue to follow the redirect and work on making the spec sensible.