fix for bug #16426, post fixes

mysql-test/r/events_slow_query.result:
  fix result
mysql-test/t/events_slow_query.test:
  create different event because the executor is buggy and won't catch the difference if
  the memory address does not change (will be reported as bug separately)
sql/sp_head.cc:
  this was an error which passed code review. thd->enable_slow_log could be
  changed and it should not be relied

mysql-test/r/events_slow_query.result

@@ -28,6 +28,9 @@ SELECT * FROM slow_event_test;
 slo_val	val
 SET GLOBAL event_scheduler=1;
 "Sleep some more time than the actual event run will take"
+SHOW VARIABLES LIKE 'event_scheduler';
+Variable_name	Value
+event_scheduler	ON
 "Check our table. Should see 1 row"
 SELECT * FROM slow_event_test;
 slo_val	val
@@ -37,7 +40,8 @@ SELECT user_host, query_time, db, sql_text FROM mysql.slow_log;
 user_host	query_time	db	sql_text
 "This should go to the slow log"
 SET SESSION long_query_time=10;
-ALTER EVENT long_event DO INSERT INTO slow_event_test SELECT @@long_query_time, SLEEP(5);
+DROP EVENT long_event;
+CREATE EVENT long_event2 ON SCHEDULE EVERY 1 MINUTE DO INSERT INTO slow_event_test SELECT @@long_query_time, SLEEP(5);
 "Sleep some more time than the actual event run will take"
 "Check our table. Should see 2 rows"
 SELECT * FROM slow_event_test;
@@ -48,7 +52,7 @@ slo_val	val
 SELECT user_host, query_time, db, sql_text FROM mysql.slow_log;
 user_host	query_time	db	sql_text
 root[root] @ localhost [localhost]	00:00:05	events_test	INSERT INTO slow_event_test SELECT @@long_query_time, SLEEP(5)
-DROP EVENT long_event;
+DROP EVENT long_event2;
 SET GLOBAL  long_query_time =@old_global_long_query_time;
 SET SESSION long_query_time =@old_session_long_query_time;
 TRUNCATE mysql.slow_log;

mysql-test/t/events_slow_query.test

@@ -40,20 +40,22 @@ SELECT * FROM slow_event_test;
 SET GLOBAL event_scheduler=1;
 --echo "Sleep some more time than the actual event run will take"
 --sleep 5
+SHOW VARIABLES LIKE 'event_scheduler';
 --echo "Check our table. Should see 1 row"
 SELECT * FROM slow_event_test;
 --echo "Check slow log. Should not see anything because 3 is under the threshold of 4 for GLOBAL, though over SESSION which is 2"
 SELECT user_host, query_time, db, sql_text FROM mysql.slow_log;
 --echo "This should go to the slow log"
 SET SESSION long_query_time=10;
-ALTER EVENT long_event DO INSERT INTO slow_event_test SELECT @@long_query_time, SLEEP(5);
+DROP EVENT long_event;
+CREATE EVENT long_event2 ON SCHEDULE EVERY 1 MINUTE DO INSERT INTO slow_event_test SELECT @@long_query_time, SLEEP(5);
 --echo "Sleep some more time than the actual event run will take"
 --sleep 7
 --echo "Check our table. Should see 2 rows"
 SELECT * FROM slow_event_test;
 --echo "Check slow log. Should see 1 row because 5 is over the threshold of 4 for GLOBAL, though under SESSION which is 10"
 SELECT user_host, query_time, db, sql_text FROM mysql.slow_log;
-DROP EVENT long_event;
+DROP EVENT long_event2;
 SET GLOBAL  long_query_time =@old_global_long_query_time;
 SET SESSION long_query_time =@old_session_long_query_time; 
 TRUNCATE mysql.slow_log;

sql/sp_head.cc

@@ -1412,7 +1412,7 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
   uint params = m_pcont->context_pvars();
   sp_rcontext *save_spcont, *octx;
   sp_rcontext *nctx = NULL;
-  bool save_enable_slow_log;
+  bool save_enable_slow_log= false;
   DBUG_ENTER("sp_head::execute_procedure");
   DBUG_PRINT("info", ("procedure %s", m_name.str));
 
@@ -1522,7 +1522,7 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
   if (!err_status)
     err_status= execute(thd);
 
-  if (thd->enable_slow_log && !(m_flags & LOG_SLOW_STATEMENTS))
+  if (save_enable_slow_log && !(m_flags & LOG_SLOW_STATEMENTS))
     thd->enable_slow_log= save_enable_slow_log;
 
   /*