Add testcases for frames with bound1 > bound2.

mysql-test/r/win.result

@@ -1118,3 +1118,62 @@ pk	a	CNT
 7	13	4
 8	14	3
 drop table t1;
+# 
+#  Try ranges that have bound1 > bound2.  The standard actually allows them
+# 
+create table t0 (a int);
+insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t1 (pk int, c int);
+insert into t1 select a+1,1 from t0;
+update t1 set c=2 where pk not in (1,2,3,4);
+select * from t1;
+pk	c
+1	1
+2	1
+3	1
+4	1
+5	2
+6	2
+7	2
+8	2
+9	2
+10	2
+select
+pk, c,
+count(*) over (partition by c
+order by pk
+rows between 1 preceding
+and 2 preceding) 
+as cnt
+from t1;
+pk	c	cnt
+1	1	0
+2	1	0
+3	1	0
+4	1	0
+5	2	0
+6	2	0
+7	2	0
+8	2	0
+9	2	0
+10	2	0
+select
+pk, c,
+count(*) over (partition by c
+order by pk
+range between 1 preceding
+and 2 preceding) 
+as cnt
+from t1;
+pk	c	cnt
+1	1	0
+2	1	0
+3	1	0
+4	1	0
+5	2	0
+6	2	0
+7	2	0
+8	2	0
+9	2	0
+10	2	0
+drop table t0, t1;

mysql-test/t/win.test

@@ -664,3 +664,36 @@ select
                           and 2 following) as CNT
 from t1;
 drop table t1;
+
+--echo # 
+--echo #  Try ranges that have bound1 > bound2.  The standard actually allows them
+--echo # 
+
+create table t0 (a int);
+insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+
+create table t1 (pk int, c int);
+insert into t1 select a+1,1 from t0;
+update t1 set c=2 where pk not in (1,2,3,4);
+select * from t1;
+
+select
+  pk, c,
+  count(*) over (partition by c
+                 order by pk
+                 rows between 1 preceding
+                          and 2 preceding) 
+                as cnt
+from t1;
+
+
+select
+  pk, c,
+  count(*) over (partition by c
+                 order by pk
+                 range between 1 preceding
+                           and 2 preceding) 
+                as cnt
+from t1;
+drop table t0, t1;
+