Bug #50087 Interval arithmetic for Event_queue_element is not portable.

Subtraction of two unsigned months yielded a (very large) positive value.
Conversion of this to a signed value was not necessarily well defined.

Solution: do the subtraction on signed values.


mysql-test/r/events_scheduling.result:
  Add test case.
mysql-test/t/events_scheduling.test:
  Add test case.
sql/event_data_objects.cc:
  Convert month to signed before doing the subtraction.

1 files changed, 19 insertions, 0 deletions

diff --git a/mysql-test/r/events_scheduling.result b/mysql-test/r/events_scheduling.result
index 7dfd10a53f8..262caea3d7f 100644
--- a/mysql-test/r/events_scheduling.result
+++ b/mysql-test/r/events_scheduling.result
@@ -82,5 +82,24 @@ DROP TABLE table_1;
 DROP TABLE table_2;
 DROP TABLE table_3;
 DROP TABLE table_4;
+
+Bug #50087 Interval arithmetic for Event_queue_element is not portable.
+
+CREATE TABLE t1(a int);
+CREATE EVENT e1 ON SCHEDULE EVERY 1 MONTH
+STARTS NOW() - INTERVAL 1 MONTH
+ENDS NOW() + INTERVAL 2 MONTH
+ON COMPLETION PRESERVE
+DO
+INSERT INTO t1 VALUES (1);
+CREATE EVENT e2 ON SCHEDULE EVERY 1 MONTH
+STARTS NOW()
+ENDS NOW() + INTERVAL 11 MONTH
+ON COMPLETION PRESERVE
+DO
+INSERT INTO t1 VALUES (1);
+DROP TABLE t1;
+DROP EVENT e1;
+DROP EVENT e2;
 DROP DATABASE events_test;
 SET GLOBAL event_scheduler=@event_scheduler;