From 6a0efc72220ff07e3ee8543180aafea9f600f999 Mon Sep 17 00:00:00 2001
From: tangenta <tangenta@126.com>
Date: Thu, 21 Jul 2022 15:59:06 +0800
Subject: [PATCH] ddl: fix update panic in the middle of multi-schema change

---
 ddl/column.go                        |  2 ++
 ddl/multi_schema_change_test.go      | 41 ++++++++++++++++++++++++++++
 planner/core/logical_plan_builder.go |  2 +-
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/ddl/column.go b/ddl/column.go
index a1888bcace351..ed05069130a93 100644
--- a/ddl/column.go
+++ b/ddl/column.go
@@ -260,6 +260,7 @@ func onDropColumn(d *ddlCtx, t *meta.Meta, job *model.Job) (ver int64, _ error)
 	case model.StateWriteOnly:
 		// write only -> delete only
 		colInfo.State = model.StateDeleteOnly
+		tblInfo.MoveColumnInfo(colInfo.Offset, len(tblInfo.Columns)-1)
 		if len(idxInfos) > 0 {
 			newIndices := make([]*model.IndexInfo, 0, len(tblInfo.Indices))
 			for _, idx := range tblInfo.Indices {
@@ -277,6 +278,7 @@ func onDropColumn(d *ddlCtx, t *meta.Meta, job *model.Job) (ver int64, _ error)
 	case model.StateDeleteOnly:
 		// delete only -> reorganization
 		colInfo.State = model.StateDeleteReorganization
+		tblInfo.MoveColumnInfo(colInfo.Offset, len(tblInfo.Columns)-1)
 		ver, err = updateVersionAndTableInfo(d, t, job, tblInfo, originalState != colInfo.State)
 		if err != nil {
 			return ver, errors.Trace(err)
diff --git a/ddl/multi_schema_change_test.go b/ddl/multi_schema_change_test.go
index c16ab46a62648..92d55fed0932c 100644
--- a/ddl/multi_schema_change_test.go
+++ b/ddl/multi_schema_change_test.go
@@ -1155,6 +1155,47 @@ func TestMultiSchemaChangeUnsupportedType(t *testing.T) {
 		"[ddl:8200]Unsupported multi schema change for modify auto id cache")
 }
 
+func TestMultiSchemaChangeMixedWithUpdate(t *testing.T) {
+	store, dom, clean := testkit.CreateMockStoreAndDomain(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test;")
+	tk.MustExec("create table t (c_1 int, c_2 char(20), c_pos_1 int, c_idx_visible int, c_3 decimal(5, 3), " +
+		"c_drop_1 time, c_4 datetime, c_drop_idx char(10), c_5 time, c_6 double, c_drop_2 int, c_pos_2 char(10), " +
+		"c_add_idx_1 int, c_add_idx_2 char(20), index idx_1(c_1), index idx_2(c_2), index idx_drop(c_drop_idx), " +
+		"index idx_3(c_drop_1), index idx_4(c_4), index idx_5(c_pos_1, c_pos_2), index idx_visible(c_idx_visible));")
+	tk.MustExec("insert into t values (100, 'c_2_insert', 101, 12, 2.1, '10:00:00', " +
+		"'2020-01-01 10:00:00', 'wer', '10:00:00', 2.1, 12, 'qwer', 12, 'asdf');")
+
+	originHook := dom.DDL().GetHook()
+	hook := &ddl.TestDDLCallback{Do: dom}
+	var checkErr error
+	hook.OnJobRunBeforeExported = func(job *model.Job) {
+		if checkErr != nil {
+			return
+		}
+		assert.Equal(t, model.ActionMultiSchemaChange, job.Type)
+		if job.MultiSchemaInfo.SubJobs[9].SchemaState == model.StateDeleteOnly {
+			tk2 := testkit.NewTestKit(t, store)
+			tk2.MustExec("use test;")
+			_, checkErr = tk2.Exec("update t set c_4 = '2020-01-01 10:00:00', c_5 = 'c_5_update', c_1 = 102, " +
+				"c_2 = '1', c_pos_1 = 102, c_idx_visible = 102, c_3 = 3.1, c_drop_idx = 'er', c_6 = 2, c_pos_2 = 'dddd', " +
+				"c_add_idx_1 = 102, c_add_idx_2 = 'zxc', c_add_2 = 10001, c_add_1 = 10001 where c_drop_idx = 'wer';")
+			if checkErr != nil {
+				return
+			}
+		}
+	}
+	dom.DDL().SetHook(hook)
+	tk.MustExec("alter table t add index i_add_1(c_add_idx_1), drop index idx_drop, " +
+		"add index i_add_2(c_add_idx_2), modify column c_2 char(100), add column c_add_2 bigint, " +
+		"modify column c_1 bigint, add column c_add_1 bigint, modify column c_5 varchar(255) first, " +
+		"modify column c_4 datetime first, drop column c_drop_1, drop column c_drop_2, modify column c_6 int, " +
+		"alter index idx_visible invisible, modify column c_3 decimal(10, 2);")
+	require.NoError(t, checkErr)
+	dom.DDL().SetHook(originHook)
+}
+
 type cancelOnceHook struct {
 	store     kv.Storage
 	triggered bool
diff --git a/planner/core/logical_plan_builder.go b/planner/core/logical_plan_builder.go
index 70ab80fa6cbc1..8e28747b11c41 100644
--- a/planner/core/logical_plan_builder.go
+++ b/planner/core/logical_plan_builder.go
@@ -5344,7 +5344,7 @@ func (b *PlanBuilder) buildUpdateLists(ctx context.Context, tableList []*ast.Tab
 		if !found {
 			return nil, nil, false, infoschema.ErrTableNotExists.GenWithStackByArgs(tn.DBInfo.Name.O, tableInfo.Name.O)
 		}
-		for i, colInfo := range tableInfo.Columns {
+		for i, colInfo := range tableVal.Cols() {
 			if !colInfo.IsGenerated() {
 				continue
 			}