fix for bug#16431 (Events: An event which alters itself disappears)

WL#1034 (Internal CRON)


mysql-test/r/events.result:
  add a test for to test bug #16431
mysql-test/t/events.test:
  results of new tests
sql/event.cc:
  - more debug info
  - pass info to evex_remove_from_cache() whether the operation 
    was drop or alter. this fixes possible bug that may lead to dropping
    of an event when it's altered. also fix for bug#16431
sql/event_executor.cc:
  be more verbose and throw more errors
sql/event_timed.cc:
  - add ` around the names of the db and the event_name and not
  their concatenation. remove ; from the end - unneeded. this fixes bug #16431,
  which was failing because after some recursion the query was ending on ;;
  which is normally an error in the parser because that's the delimiter
  
  - more debug info
  - don't execute lex_end() two times when there's a parse error or thd->is_fatal_error

1 files changed, 17 insertions, 0 deletions

diff --git a/mysql-test/r/events.result b/mysql-test/r/events.result
index 4e1648de6b9..c3b94e580c2 100644
--- a/mysql-test/r/events.result
+++ b/mysql-test/r/events.result
@@ -12,6 +12,23 @@ alter event event3 rename to event2;
 drop event event2;
 create event event2 on schedule every 2 second starts now() ends date_add(now(), interval 5 hour) comment "some" DO begin end;
 drop event event2;
+create event e_43 on schedule every 1 second do set @a = 5;
+set global event_scheduler = 1;
+select sleep(2);
+sleep(2)
+0
+alter event e_43 do alter event e_43 do set @a = 4;
+select sleep(3);
+sleep(3)
+0
+select db, name, body, status, interval_field, interval_value from mysql.event;
+db	name	body	status	interval_field	interval_value
+events_test	e_43	 set @a = 4	ENABLED	SECOND	1
+drop event e_43;
+select sleep(1);
+sleep(1)
+0
+set global event_scheduler = 0;
 create table t_event3 (a int, b float);
 drop event if exists event3;
 Warnings: