From 2c40c11c8359b12d7c3e4d498c0fb18730d73f92 Mon Sep 17 00:00:00 2001
From: Mikael Ronstrom <mikael@dator8>
Date: Tue, 9 Nov 2010 16:33:40 +0100
Subject: [PATCH] Added support in DEBUG_SYNC framework for actions when THD
 object isn't actively executed, that is when mysys_var == NULL

---
 sql/debug_sync.cc | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/sql/debug_sync.cc b/sql/debug_sync.cc
index 74e5b2c70f3..1390bac8352 100644
--- a/sql/debug_sync.cc
+++ b/sql/debug_sync.cc
@@ -1746,10 +1746,15 @@ static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
         mutex and cond. This would prohibit the use of DEBUG_SYNC
         between other places of enter_cond() and exit_cond().
       */
-      old_mutex= thd->mysys_var->current_mutex;
-      old_cond= thd->mysys_var->current_cond;
-      thd->mysys_var->current_mutex= &debug_sync_global.ds_mutex;
-      thd->mysys_var->current_cond= &debug_sync_global.ds_cond;
+      if (thd->mysys_var)
+      {
+        old_mutex= thd->mysys_var->current_mutex;
+        old_cond= thd->mysys_var->current_cond;
+        thd->mysys_var->current_mutex= &debug_sync_global.ds_mutex;
+        thd->mysys_var->current_cond= &debug_sync_global.ds_cond;
+      }
+      else
+        old_mutex= NULL;
 
       set_timespec(abstime, action->timeout);
       DBUG_EXECUTE("debug_sync_exec", {
@@ -1804,11 +1809,16 @@ static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
         is locked. (See comment in THD::exit_cond().)
       */
       mysql_mutex_unlock(&debug_sync_global.ds_mutex);
-      mysql_mutex_lock(&thd->mysys_var->mutex);
-      thd->mysys_var->current_mutex= old_mutex;
-      thd->mysys_var->current_cond= old_cond;
-      thd_proc_info(thd, old_proc_info);
-      mysql_mutex_unlock(&thd->mysys_var->mutex);
+      if (old_mutex)
+      {
+        mysql_mutex_lock(&thd->mysys_var->mutex);
+        thd->mysys_var->current_mutex= old_mutex;
+        thd->mysys_var->current_cond= old_cond;
+        thd_proc_info(thd, old_proc_info);
+        mysql_mutex_unlock(&thd->mysys_var->mutex);
+      }
+      else
+        thd_proc_info(thd, old_proc_info);
     }
     else
     {