Fix final test for invalid base64url chars

* src/fns.c (base64_decode_1): Fix test for invalid base64url
(bug#45562).  Noted by Andreas Schwab.

diff --git a/src/fns.c b/src/fns.c
index a178216622819b934dcf2eaca8ece691c955a82b..7b9e3b0f7fc46589f3d22f385f95204066052c3c 100644 (file)
--- 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;