From ed28d986e97a0e7b22b58de2ceaaee9e8416634f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markus=20M=C3=A4kel=C3=A4?= <markus.makela@mariadb.com>
Date: Wed, 7 Feb 2018 17:56:15 +0200
Subject: [PATCH] Fix debug assertion when no master is present

If no master is present, the debug assertion would dereference a NULL
pointer.
---
 server/modules/monitor/mariadbmon/mysql_mon.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/modules/monitor/mariadbmon/mysql_mon.cc b/server/modules/monitor/mariadbmon/mysql_mon.cc
index 51586f3db..0c83bf942 100644
--- a/server/modules/monitor/mariadbmon/mysql_mon.cc
+++ b/server/modules/monitor/mariadbmon/mysql_mon.cc
@@ -2372,7 +2372,7 @@ monitorMain(void *arg)
             }
         }
 
-        ss_dassert(handle->master == root_master);
+        ss_dassert(root_master == NULL || handle->master == root_master);
         ss_dassert(!root_master ||
                    ((root_master->server->status & (SERVER_SLAVE | SERVER_MASTER))
                     != (SERVER_SLAVE | SERVER_MASTER)));