From d9ab0c4bcbad725de23bc45312884b856a3a6681 Mon Sep 17 00:00:00 2001
From: Juliusz Sosinowicz <juliusz@wolfssl.com>
Date: Tue, 29 Oct 2019 12:08:47 +0100
Subject: [PATCH] Check bounds

---
 src/ssl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ssl.c b/src/ssl.c
index f487741bc..f4984536b 100644
--- a/src/ssl.c
+++ b/src/ssl.c
@@ -39554,7 +39554,7 @@ int wolfSSL_X509_NAME_print_ex(WOLFSSL_BIO* bio, WOLFSSL_X509_NAME* name,
             }
             totalSz += tmpSz;
         }
-        if (fullName[totalSz-1] == '\0')
+        if (totalSz > 0 && fullName[totalSz-1] == '\0')
         	totalSz--;
         if (wolfSSL_BIO_write(bio, fullName, totalSz) != totalSz)
             return WOLFSSL_FAILURE;