From 23f9cad7755e570818a093f90197a0f494cf560b Mon Sep 17 00:00:00 2001
From: xuhuaiyu <391585975@qq.com>
Date: Wed, 10 Jun 2020 16:59:35 +0800
Subject: [PATCH] planner, util: new unfixed mutrow for TypeNull

---
 planner/core/integration_test.go | 11 +++++++++++
 util/chunk/codec.go              |  2 +-
 util/chunk/mutrow.go             |  2 +-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/planner/core/integration_test.go b/planner/core/integration_test.go
index 82f4c396695d2..ee5e5bcf7cd26 100644
--- a/planner/core/integration_test.go
+++ b/planner/core/integration_test.go
@@ -1117,3 +1117,14 @@ func (s *testIntegrationSuite) TestHintParserWarnings(c *C) {
 	rows := tk.MustQuery("show warnings;").Rows()
 	c.Assert(len(rows), Equals, 1)
 }
+
+func (s *testIntegrationSuite) TestIssue16935(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t0;")
+	tk.MustExec("CREATE TABLE t0(c0 INT);")
+	tk.MustExec("INSERT INTO t0(c0) VALUES (1), (1), (1), (1), (1), (1);")
+	tk.MustExec("CREATE definer='root'@'localhost' VIEW v0(c0) AS SELECT NULL FROM t0;")
+
+	tk.MustQuery("SELECT * FROM t0 LEFT JOIN v0 ON TRUE WHERE v0.c0 IS NULL;")
+}
diff --git a/util/chunk/codec.go b/util/chunk/codec.go
index 9d0636f410119..2858fb89b55a7 100644
--- a/util/chunk/codec.go
+++ b/util/chunk/codec.go
@@ -173,7 +173,7 @@ func getFixedLen(colType *types.FieldType) int {
 	case mysql.TypeFloat:
 		return 4
 	case mysql.TypeTiny, mysql.TypeShort, mysql.TypeInt24, mysql.TypeLong,
-		mysql.TypeLonglong, mysql.TypeDouble, mysql.TypeYear, mysql.TypeDuration, mysql.TypeNull:
+		mysql.TypeLonglong, mysql.TypeDouble, mysql.TypeYear, mysql.TypeDuration:
 		return 8
 	case mysql.TypeDate, mysql.TypeDatetime, mysql.TypeTimestamp:
 		return sizeTime
diff --git a/util/chunk/mutrow.go b/util/chunk/mutrow.go
index f0f2138cbd6e8..46a9a3a1fe850 100644
--- a/util/chunk/mutrow.go
+++ b/util/chunk/mutrow.go
@@ -121,7 +121,7 @@ func zeroValForType(tp *types.FieldType) interface{} {
 func makeMutRowColumn(in interface{}) *Column {
 	switch x := in.(type) {
 	case nil:
-		col := makeMutRowUint64Column(uint64(0))
+		col := makeMutRowBytesColumn(nil)
 		col.nullBitmap[0] = 0
 		return col
 	case int: