From bb2d1252e6da6202ebf7015ad9615b31fe993fdc Mon Sep 17 00:00:00 2001
From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Wed, 21 Jul 2021 13:28:17 +0200
Subject: [PATCH] Fix final test for invalid base64url chars

* src/fns.c (base64_decode_1): Fix test for invalid base64url
(bug#45562).  Noted by Andreas Schwab.
---
 src/fns.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/fns.c b/src/fns.c
index a1782166228..7b9e3b0f7fc 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -3955,7 +3955,7 @@ base64_decode_1 (const char *from, char *to, ptrdiff_t length,
       if (c == '=')
 	continue;
 
-      if (v1 < 0)
+      if (v1 == 0)
 	return -1;
       value += v1 - 1;
 
-- 
2.39.2