From 2b30b132b21ab2533b60d92bef5cd0d471670a69 Mon Sep 17 00:00:00 2001
From: hybrid2102 <diannimarco@gmail.com>
Date: Tue, 28 Nov 2023 14:19:57 +0100
Subject: [PATCH] after refreshing the token, if the response does not contain
 a new RefreshToken, retrieve the previous one

---
 .../UserTokenEndpointService.cs                                 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Duende.AccessTokenManagement.OpenIdConnect/UserTokenEndpointService.cs b/src/Duende.AccessTokenManagement.OpenIdConnect/UserTokenEndpointService.cs
index f0173b4..c9ee20b 100755
--- a/src/Duende.AccessTokenManagement.OpenIdConnect/UserTokenEndpointService.cs
+++ b/src/Duende.AccessTokenManagement.OpenIdConnect/UserTokenEndpointService.cs
@@ -143,7 +143,7 @@ public async Task<UserToken> RefreshAccessTokenAsync(
             token.Expiration = response.ExpiresIn == 0
                 ? DateTimeOffset.MaxValue
                 : DateTimeOffset.UtcNow.AddSeconds(response.ExpiresIn);
-            token.RefreshToken = response.RefreshToken;
+            token.RefreshToken = response.RefreshToken ?? userToken.RefreshToken;
             token.Scope = response.Scope;    
         }