one more test

mysql-test/r/insert_update.result

@@ -41,4 +41,11 @@ a	b	c
 3	4	120
 5	6	30
 8	9	60
+INSERT t1 SET a=5 ON DUPLICATE KEY UPDATE SET b=0;
+SELECT * FROM t1;
+a	b	c
+1	2	10
+3	4	120
+5	0	30
+8	9	60
 DROP TABLE t1;

mysql-test/t/insert_update.test

@@ -16,4 +16,6 @@ TRUNCATE TABLE t1;
 INSERT t1 VALUES (1,2,10), (3,4,20);
 INSERT t1 VALUES (5,6,30), (7,4,40), (8,9,60) ON DUPLICATE KEY UPDATE SET c=c+100;
 SELECT * FROM t1;
+INSERT t1 SET a=5 ON DUPLICATE KEY UPDATE SET b=0;
+SELECT * FROM t1;
 DROP TABLE t1;