Bug#21555: incorrect behavior with INSERT ... ON DUPL KEY UPDATE and VALUES

 VALUES() was considered a constant. This caused replacing 
 (or pre-calculating) it using uninitialized values before the actual
 execution takes place.
 Mark it as a non-constant (still not dependent of tables) to prevent
 the pre-calculation.


mysql-test/r/insert_update.result:
  Bug#21555: incorrect behavior with INSERT ... ON DUPL KEY UPDATE and VALUES
   - test case.
   - EXPLAIN output changed due to VALUES() not being considered a constant 
     anymore
mysql-test/t/insert_update.test:
  Bug#21555: incorrect behavior with INSERT ... ON DUPL KEY UPDATE and VALUES
   - test case.
sql/item.h:
  Bug#21555: incorrect behavior with INSERT ... ON DUPL KEY UPDATE and VALUES
   - mark Item_insert_value as non-constant to prevent early calculation.

1 files changed, 23 insertions, 0 deletions

diff --git a/mysql-test/t/insert_update.test b/mysql-test/t/insert_update.test
index 8038bd7bfe7..56885a555fd 100644
--- a/mysql-test/t/insert_update.test
+++ b/mysql-test/t/insert_update.test
@@ -115,4 +115,27 @@ INSERT INTO t1 ( a ) SELECT 0 ON DUPLICATE KEY UPDATE a = a + VALUES (a) ;
 
 DROP TABLE t1;
 
+#
+# Bug#21555: incorrect behavior with INSERT ... ON DUPL KEY UPDATE and VALUES
+#
+
+
 # End of 4.1 tests
+CREATE TABLE t1
+(
+  a   BIGINT UNSIGNED,
+  b   BIGINT UNSIGNED,
+  PRIMARY KEY (a)
+);
+
+INSERT INTO t1 VALUES (45, 1) ON DUPLICATE KEY UPDATE b =
+  IF(VALUES(b) > t1.b, VALUES(b), t1.b);
+SELECT * FROM t1;
+INSERT INTO t1 VALUES (45, 2) ON DUPLICATE KEY UPDATE b =
+  IF(VALUES(b) > t1.b, VALUES(b), t1.b);
+SELECT * FROM t1;
+INSERT INTO t1 VALUES (45, 1) ON DUPLICATE KEY UPDATE b = 
+  IF(VALUES(b) > t1.b, VALUES(b), t1.b);
+SELECT * FROM t1;
+
+DROP TABLE t1;