From e2dba64c8460a3c08cd6021184b5a8163df28306 Mon Sep 17 00:00:00 2001
From: Rich Salz <rsalz@openssl.org>
Date: Thu, 15 Jun 2017 18:51:10 -0400
Subject: [PATCH] Fix crash

[extended tests]

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3700)
---
 crypto/err/err.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/crypto/err/err.c b/crypto/err/err.c
index 906e3543e1..e50c6d6f9d 100644
--- a/crypto/err/err.c
+++ b/crypto/err/err.c
@@ -757,6 +757,8 @@ void ERR_add_error_vdata(int num, va_list args)
     n = 0;
     for (i = 0; i < num; i++) {
         a = va_arg(args, char *);
+        if (a == NULL)
+            a = "<NULL>";
         n += strlen(a);
         if (n > s) {
             s = n + 20;
-- 
2.25.1