Remove x-webkit-deflate-frame dead code

Author: abursavich

Diff for: accept.go

@@ -240,9 +240,6 @@ func selectDeflate(extensions []websocketExtension, mode CompressionMode) (*comp
 			if copts, ok := acceptDeflate(ext, mode); ok {
 				return copts, true
 			}
-			// Disabled for now, see https://github.com/nhooyr/websocket/issues/218
-			// case "x-webkit-deflate-frame":
-			// 	return acceptWebkitDeflate(w, ext, mode)
 		}
 	}
 	return nil, false
@@ -271,40 +268,6 @@ func acceptDeflate(ext websocketExtension, mode CompressionMode) (*compressionOp
 	return copts, true
 }
 
-func acceptWebkitDeflate(w http.ResponseWriter, ext websocketExtension, mode CompressionMode) (*compressionOptions, error) {
-	copts := mode.opts()
-	// The peer must explicitly request it.
-	copts.serverNoContextTakeover = false
-
-	for _, p := range ext.params {
-		if p == "no_context_takeover" {
-			copts.serverNoContextTakeover = true
-			continue
-		}
-
-		// We explicitly fail on x-webkit-deflate-frame's max_window_bits parameter instead
-		// of ignoring it as the draft spec is unclear. It says the server can ignore it
-		// but the server has no way of signalling to the client it was ignored as the parameters
-		// are set one way.
-		// Thus us ignoring it would make the client think we understood it which would cause issues.
-		// See https://tools.ietf.org/html/draft-tyoshino-hybi-websocket-perframe-deflate-06#section-4.1
-		//
-		// Either way, we're only implementing this for webkit which never sends the max_window_bits
-		// parameter so we don't need to worry about it.
-		err := fmt.Errorf("unsupported x-webkit-deflate-frame parameter: %q", p)
-		http.Error(w, err.Error(), http.StatusBadRequest)
-		return nil, err
-	}
-
-	s := "x-webkit-deflate-frame"
-	if copts.clientNoContextTakeover {
-		s += "; no_context_takeover"
-	}
-	w.Header().Set("Sec-WebSocket-Extensions", s)
-
-	return copts, nil
-}
-
 func headerContainsToken(h http.Header, key, token string) bool {
 	token = strings.ToLower(token)
 

Diff for: accept_test.go

@@ -396,22 +396,6 @@ func Test_selectDeflate(t *testing.T) {
 			},
 			expOK: true,
 		},
-		// {
-		// 	name:                       "x-webkit-deflate-frame",
-		// 	mode:                       CompressionNoContextTakeover,
-		// 	reqSecWebSocketExtensions:  "x-webkit-deflate-frame; no_context_takeover",
-		// 	respSecWebSocketExtensions: "x-webkit-deflate-frame; no_context_takeover",
-		// 	expCopts: &compressionOptions{
-		// 		clientNoContextTakeover: true,
-		// 		serverNoContextTakeover: true,
-		// 	},
-		// },
-		// {
-		// 	name:                      "x-webkit-deflate/error",
-		// 	mode:                      CompressionNoContextTakeover,
-		// 	reqSecWebSocketExtensions: "x-webkit-deflate-frame; max_window_bits",
-		// 	error:                     true,
-		// },
 	}
 
 	for _, tc := range testCases {