MDEV-15204: lag/lead function order list mandatory

2 files changed, 15 insertions, 2 deletions

diff --git a/mysql-test/t/win.test b/mysql-test/t/win.test
index b354a55d0d6..f47237ee59e 100644
--- a/mysql-test/t/win.test
+++ b/mysql-test/t/win.test
@@ -2000,8 +2000,8 @@ DROP TABLE fv_test, fv_result;
 
 CREATE TABLE t1 (a int);
 INSERT INTO t1 VALUES (0),(1),(2);
-SELECT LEAD(a) OVER (PARTITION BY a) as lead,
-       a AND LEAD(a) OVER (PARTITION BY a) AS a_and_lead_part
+SELECT LEAD(a) OVER (PARTITION BY a ORDER BY a) as lead,
+       a AND LEAD(a) OVER (PARTITION BY a ORDER BY a) AS a_and_lead_part
 FROM t1;
 
 SELECT a OR LEAD(a) OVER (ORDER BY a) AS a_or_lead_order
diff --git a/mysql-test/t/win_lead_lag.test b/mysql-test/t/win_lead_lag.test
index 2824f83789c..d154244ecd0 100644
--- a/mysql-test/t/win_lead_lag.test
+++ b/mysql-test/t/win_lead_lag.test
@@ -107,4 +107,17 @@ select pk, a, b, a+b,
 from t1
 order by pk asc;
 
+--echo #
+--echo # MDEV-15204 - LAG function doesn't require ORDER BY in OVER clause
+--echo #
+--error ER_NO_ORDER_LIST_IN_WINDOW_SPEC
+select pk,
+       lag(pk, 1) over ()
+from t1;
+
+--error ER_NO_ORDER_LIST_IN_WINDOW_SPEC
+select pk,
+       lead(pk, 1) over ()
+from t1;
+
 drop table t1;