From f5b0ea4e1452746d929288ff33a8016a0cfde9b0 Mon Sep 17 00:00:00 2001
From: Almog Baku <almog.baku@gmail.com>
Date: Thu, 10 Oct 2019 04:41:58 +0300
Subject: [PATCH] Keep the old refresh_token when not present

---
 oauth2.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/oauth2.go b/oauth2.go
index 291df5c83..f5ffcc7fd 100644
--- a/oauth2.go
+++ b/oauth2.go
@@ -275,7 +275,7 @@ func (tf *tokenRefresher) Token() (*Token, error) {
 	if err != nil {
 		return nil, err
 	}
-	if tf.refreshToken != tk.RefreshToken {
+	if tf.refreshToken != tk.RefreshToken && tk.RefreshToken != "" {
 		tf.refreshToken = tk.RefreshToken
 	}
 	return tk, err