[undertow-dev] Redirects during the handshake of a WebSocket upgrade request

Hi, I see some people think the HTTP request for a WebSocket upgrade shouldn't honnor 301/302 redirects. But the spec seems to say it is ok: "/If the status code received from the server is not 101, the// //client handles the response per HTTP [RFC2616] procedures. In// //particular, the client might perform authentication if it// //receives a 401 status code; the server might redirect the client// //using a 3xx status code (but clients are not required to follow// //them), etc. Otherwise, proceed as follows/." "/The server MAY redirect the client using a 3xx status code// //[RFC2616]. Note that this step can happen together with, before,// //or after the optional authentication step described above./" https://tools.ietf.org/html/rfc6455 In the version of Undertow I use, 1.2.12.Final, I see that the redirect response is handled by /org.xnio.http.HttpUpgrade/ : private void handleRedirect(final HttpUpgradeParser parser) { List<String> location = parser.getHeaders().get("location"); future.setException(new RedirectException(msg.redirect(), parser.getResponseCode(), location == null ? null : location.get(0))); } Is it the same behavior in most recent Undertow releases? Related discussion: https://github.com/sta/websocket-sharp/issues/42 Thanks, Julien