Merge pull request etcd-io#12932 from vvdvortsova/12821-fix-req-maybe…

…-nil

embed: Added a check for a nil value of the request in ServeHTTP method

server/embed/serve.go

@@ -303,8 +303,12 @@ type accessController struct {
 }
 
 func (ac *accessController) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	if req == nil {
+		http.Error(rw, "Request is nil", http.StatusBadRequest)
+		return
+	}
 	// redirect for backward compatibilities
-	if req != nil && req.URL != nil && strings.HasPrefix(req.URL.Path, "/v3beta/") {
+	if req.URL != nil && strings.HasPrefix(req.URL.Path, "/v3beta/") {
 		req.URL.Path = strings.Replace(req.URL.Path, "/v3beta/", "/v3/", 1)
 	}