wrlock(LOCK_grant)                 -> lock(acl_cache->lock)               GRANT/REVOKE CREATE/DROP USER

lock(LOCK_open)                    -> rdlock(LOCK_grant)                  SELECT * FROM INFORMATION_SCHEMA.COLUMNS

wrlock(LOCK_logger)                -> lock(LOCK_open)                     SET @@global.slow_query_log='ON'

lock(acl_cache->lock)              -> rdlock(LOCK_logger)                 Failed connection

--source include/have_plugin_auth.inc

--source include/have_debug_sync.inc

SET @@global.slow_query_log='OFF';

CREATE USER plug_user IDENTIFIED WITH test_plugin_server AS 'plug_dest';

CREATE USER plug_dest IDENTIFIED BY 'plug_dest_passwd';

GRANT PROXY ON plug_dest TO plug_user;

RENAME USER plug_dest TO new_dest;

connect(con1, localhost, root,,);

connect(con2, localhost, root,,);

connect(con3, localhost, root,,);

connection con1;

SET debug_sync='mysql_grant SIGNAL ready1 WAIT_FOR go1';

SET debug_dbug='+d,mysql_grant';

send REVOKE ALL ON *.* FROM no_such_user@localhost;

connection con2;

SET debug_sync='now WAIT_FOR ready1';

SET debug_sync='fill_schema_table_from_frm SIGNAL ready2 WAIT_FOR go2';

send SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS;

connection con3;

SET debug_sync='now WAIT_FOR ready2';

SET debug_sync='activate_log_handler SIGNAL ready3 WAIT_FOR go3';

SET debug_dbug='+d,activate_log_handler';

send SET @@global.slow_query_log='ON';

connection default;

SET debug_sync='now WAIT_FOR ready3';

--error 1

--exec $MYSQL -S $MASTER_MYSOCK -u plug_user --password=plug_dest -e "SELECT 1;"

connection con1;

--error 1141

reap;

disconnect con1;

connection con2;

reap;

disconnect con2;

connection con3;

reap;

disconnect con3;

connection default;

DROP USER plug_user, new_dest;

SET debug_sync='RESET';

=== modified file 'sql/log.cc'

--- sql/log.cc	2014-08-02 19:26:16 +0000

+++ sql/log.cc	2014-09-18 15:16:51 +0000

@@ -1400,7 +1400,12 @@ bool LOGGER::activate_log_handler(THD* t

 {

   MYSQL_QUERY_LOG *file_log;

   bool res= FALSE;

+  DEBUG_SYNC(thd, "activate_log_handler");

   lock_exclusive();

+  DBUG_EXECUTE_IF("activate_log_handler",

+  {

+    debug_sync_set_action(thd, STRING_WITH_LEN("now SIGNAL ready3"));

+  };);

   switch (log_type) {

   case QUERY_LOG_SLOW:

     if (!opt_slow_log)

=== modified file 'sql/sql_acl.cc'

--- sql/sql_acl.cc	2014-08-02 19:26:16 +0000

+++ sql/sql_acl.cc	2014-09-18 15:18:52 +0000

@@ -53,6 +53,7 @@

 #include "sql_array.h"

 #include "sql_plugin_compat.h"

+#include "debug_sync.h"

 bool mysql_user_table_is_in_short_password_format= false;

@@ -4142,8 +4143,13 @@ bool mysql_grant(THD *thd, const char *d

   if (!revoke_grant)

     create_new_users= test_if_create_new_users(thd);

+  DEBUG_SYNC(thd, "mysql_grant");

   /* go through users in user_list */

   mysql_rwlock_wrlock(&LOCK_grant);

+  DBUG_EXECUTE_IF("mysql_grant",

+  {

+    debug_sync_set_action(thd, STRING_WITH_LEN("now SIGNAL ready1"));

+  };);

   mysql_mutex_lock(&acl_cache->lock);

   grant_version++;

@@ -9225,7 +9231,12 @@ bool acl_authenticate(THD *thd, uint con

       if (!acl_proxy_user)

       {

         if (!thd->is_error())

+        {

+          debug_sync_set_action(thd, STRING_WITH_LEN("now SIGNAL go1 WAIT_FOR ready1"));

+          debug_sync_set_action(thd, STRING_WITH_LEN("now SIGNAL go2"));

+          debug_sync_set_action(thd, STRING_WITH_LEN("now SIGNAL go3 WAIT_FOR ready3"));

           login_failed_error(thd);

+        }

         mysql_mutex_unlock(&acl_cache->lock);

         DBUG_RETURN(1);

       }

=== modified file 'sql/sql_show.cc'

--- sql/sql_show.cc	2014-08-31 17:55:11 +0000

+++ sql/sql_show.cc	2014-09-18 15:07:47 +0000

@@ -4244,6 +4244,7 @@ static int fill_schema_table_from_frm(TH

   key_length= create_table_def_key(thd, key, &table_list, 0);

   hash_value= my_calc_hash(&table_def_cache, (uchar*) key, key_length);

   mysql_mutex_lock(&LOCK_open);

+  DEBUG_SYNC(thd, "fill_schema_table_from_frm");

   share= get_table_share(thd, &table_list, key,

                          key_length, OPEN_VIEW, &not_used, hash_value);

   if (!share)