BUG#16420: Events: timestamps become UTC

BUG#26429: SHOW CREATE EVENT is incorrect for an event that
           STARTS NOW()
BUG#26431: Impossible to re-create an event from backup if its
           STARTS clause is in the past
WL#3698: Events: execution in local time zone

The problem was that local times specified by the user in AT, STARTS
and ENDS of CREATE EVENT/ALTER EVENT statement were converted to UTC,
and the original time zone was forgotten.  This way, event scheduler
couldn't honor Daylight Saving Time shifts, and times shown to the
user were also in UTC.  Additionally, CREATE EVENT didn't allow times
in the past, thus preventing straightforward event restoration from
old backups.

This patch reworks event scheduler time computations, performing them
in the time zone associated with the event.  Also it allows times to
be in the past.

The patch adds time_zone column to mysql.event table.

NOTE: The patch is almost final, but the bug#9953 should be pushed
first.

1 files changed, 1 insertions, 1 deletions

diff --git a/sql/event_queue.h b/sql/event_queue.h
index a1237e1b52c..338a6c8f903 100644
--- a/sql/event_queue.h
+++ b/sql/event_queue.h
@@ -86,7 +86,7 @@ protected:
   /* The sorted queue with the Event_queue_element objects */
   QUEUE queue;
 
-  TIME next_activation_at;
+  my_time_t next_activation_at;
 
   uint mutex_last_locked_at_line;
   uint mutex_last_unlocked_at_line;