From 924a81a548994bd61e9b8ea662bdb64ef1c12ea0 Mon Sep 17 00:00:00 2001
From: Sergei Golubchik <serg@mariadb.org>
Date: Sat, 18 Feb 2017 15:06:25 +0100
Subject: [PATCH] bugfix: DEBUG_SYNC() invoked with no THD

While DEBUG_SYNC doesn't make sense without a valid THD, it might
be put in the code that's invoked both within and outside of a
THD context (e.g. in maria_open(), there is no THD during recovery).
---
 sql/debug_sync.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sql/debug_sync.cc b/sql/debug_sync.cc
index 4cff1c09ba7..82203505f50 100644
--- a/sql/debug_sync.cc
+++ b/sql/debug_sync.cc
@@ -1520,6 +1520,8 @@ static void debug_sync(THD *thd, const char *sync_point_name, size_t name_len)
 {
   if (!thd)
     thd= current_thd;
+  if (!thd)
+    return;
 
   st_debug_sync_control *ds_control= thd->debug_sync_control;
   st_debug_sync_action  *action;