From 1c1699545b0a1114e8ca3e6cd097cc9df1e67201 Mon Sep 17 00:00:00 2001
From: Marc Hoersken <info@marc-hoersken.de>
Date: Mon, 15 Dec 2014 00:17:10 +0100
Subject: [PATCH] kex.c: fix possible NULL pointer de-reference with
 session->kex

Fixes VS2012 code analysis warning C6011:
dereferencing NULL pointer 'session->kex'. libssh2 kex.c 1761
---
 src/kex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/kex.c b/src/kex.c
index 07e717f2..ca227b84 100644
--- a/src/kex.c
+++ b/src/kex.c
@@ -1756,7 +1756,7 @@ _libssh2_kex_exchange(LIBSSH2_SESSION * session, int reexchange,
         key_state->state = libssh2_NB_state_sent2;
     }
 
-    if (rc == 0) {
+    if (rc == 0 && session->kex) {
         if (key_state->state == libssh2_NB_state_sent2) {
             retcode = session->kex->exchange_keys(session,
                                                   &key_state->key_state_low);