TiDB can insert duplicate key by insert ingore statements during modify column

[wjhuang2016]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

modify code:

 var TestReorgGoroutineRunning = make(chan interface{})

+var MockDMLExec func()
+
 // updateCurrentElement update the current element for reorgInfo.
 func (w *worker) updateCurrentElement(t table.Table, reorgInfo *reorgInfo) error {
        failpoint.Inject("mockInfiniteReorgLogic", func(val failpoint.Value) {
@@ -1146,6 +1148,9 @@ func (w *worker) updateCurrentElement(t table.Table, reorgInfo *reorgInfo) error
                if err != nil {
                        return errors.Trace(err)
                }
+               if MockDMLExec != nil {
+                       MockDMLExec()
+               }
                err = w.addTableIndex(t, reorgInfo)

Then tests:

func TestIssueInsertIngore(t *testing.T) {
	store, _ := testkit.CreateMockStoreAndDomainWithSchemaLease(t, dbTestLease)

	tk := testkit.NewTestKit(t, store)
	tk.MustExec("use test")
	tk1 := testkit.NewTestKit(t, store)
	tk1.MustExec("use test")

	tk.MustExec("drop table if exists t")
	tk.MustExec("create table t (a double, b int, c int, unique key (a));")

	j := 0
	var cerr error
	ddl.MockDMLExec = func() {
		j++
		logutil.BgLogger().Info("mock dml", zap.Int("j", j))
		if j == 1 {
			_, cerr = tk1.Exec("insert ignore into t values (200, 1, 1), (300, 1, 1), (400, 1, 1);")
		}
	}

	done := make(chan error, 1)
	// test transaction on add column.
	go backgroundExec(store, "alter table t modify column a tinyint;", done)
	err := <-done
	require.NoError(t, err)
	require.NoError(t, cerr)
	tk.MustExec("admin check table t")
}

2. What did you expect to see? (Required)

test pass

3. What did you see instead (Required)

test failed with

Received unexpected error:
        	            	[admin:8223]data inconsistency in table: t, index: a, handle: 1, index-values:"" != record-values:"handle: 1, values: [KindInt64 127]"
        	            	github.com/pingcap/errors.AddStack

4. What is your TiDB version? (Required)

v6.5.8

[tangenta]

Fixed by #40198, we need to cherry-pick the fix to v6.5.

[cfzjywxk]

@tangenta
Can this issue be closed or it need more fixes?

[jebter]

@YangKeao Can this issue be closed or it need more fixes?

[YangKeao]

Yes. Close it now