master bb2d125: Fix final test for invalid base64url chars

[Lars Ingebrigtsen]

branch: master
commit bb2d1252e6da6202ebf7015ad9615b31fe993fdc
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    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 a178216..7b9e3b0 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;