fix header-based websocket earlydata compat

transport/internet/websocket/hub.go

@@ -38,6 +38,7 @@ var upgrader = &websocket.Upgrader{
 }
 
 func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
+	var earlyDataStr string
 	var earlyData io.Reader
 	if !h.earlyDataEnabled { // nolint: gocritic
 		if request.URL.Path != h.path {
@@ -49,11 +50,11 @@ func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Req
 			writer.WriteHeader(http.StatusNotFound)
 			return
 		}
-		earlyDataStr := request.Header.Get(h.earlyDataHeaderName)
+		earlyDataStr = request.Header.Get(h.earlyDataHeaderName)
 		earlyData = base64.NewDecoder(base64.RawURLEncoding, bytes.NewReader([]byte(earlyDataStr)))
 	} else {
 		if strings.HasPrefix(request.URL.RequestURI(), h.path) {
-			earlyDataStr := request.URL.RequestURI()[len(h.path):]
+			earlyDataStr = request.URL.RequestURI()[len(h.path):]
 			earlyData = base64.NewDecoder(base64.RawURLEncoding, bytes.NewReader([]byte(earlyDataStr)))
 		} else {
 			writer.WriteHeader(http.StatusNotFound)
@@ -61,7 +62,12 @@ func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Req
 		}
 	}
 
-	conn, err := upgrader.Upgrade(writer, request, nil)
+	responseHeader := http.Header{}
+	if h.earlyDataEnabled && h.earlyDataHeaderName != "" {
+		responseHeader.Set(h.earlyDataHeaderName, earlyDataStr)
+	}
+
+	conn, err := upgrader.Upgrade(writer, request, responseHeader)
 	if err != nil {
 		newError("failed to convert to WebSocket connection").Base(err).WriteToLog()
 		return