*: add some tests for writing-data corner cases (pingcap#9199)

executor/write_test.go

@@ -21,6 +21,7 @@ import (
 	"sync/atomic"
 
 	. "github.com/pingcap/check"
+	gofail "github.com/pingcap/gofail/runtime"
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/tidb/executor"
 	"github.com/pingcap/tidb/kv"
@@ -1270,6 +1271,8 @@ func (s *testSuite) TestUpdate(c *C) {
 	r1 := tk.MustQuery("select ts from tsup use index (idx);")
 	r2 := tk.MustQuery("select ts from tsup;")
 	r1.Check(r2.Rows())
+	tk.MustExec("update tsup set ts='2019-01-01';")
+	tk.MustQuery("select ts from tsup;").Check(testkit.Rows("2019-01-01 00:00:00"))
 
 	// issue 5532
 	tk.MustExec("create table decimals (a decimal(20, 0) not null)")
@@ -2433,3 +2436,20 @@ func (s *testSuite2) TestDefEnumInsert(c *C) {
 	tk.MustExec("insert into test (id)  values (1)")
 	tk.MustQuery("select prescription_type from test").Check(testkit.Rows("a"))
 }
+
+func (s *testSuite2) TestAutoIDInRetry(c *C) {
+	tk := testkit.NewTestKitWithInit(c, s.store)
+	tk.MustExec("create table t (id int not null auto_increment primary key)")
+
+	tk.MustExec("begin")
+	tk.MustExec("insert into t values ()")
+	tk.MustExec("insert into t values (),()")
+	tk.MustExec("insert into t values ()")
+
+	gofail.Enable("github.com/pingcap/tidb/session/mockCommitRetryForAutoID", `return(true)`)
+	tk.MustExec("commit")
+	gofail.Disable("github.com/pingcap/tidb/session/mockCommitRetryForAutoID")
+
+	tk.MustExec("insert into t values ()")
+	tk.MustQuery(`select * from t`).Check(testkit.Rows("1", "2", "3", "4", "5"))
+}

session/txn.go

@@ -146,6 +146,8 @@ type dirtyTableOperation struct {
 	row    []types.Datum
 }
 
+var hasMockAutoIDRetry = false
+
 // Commit overrides the Transaction interface.
 func (st *TxnState) Commit(ctx context.Context) error {
 	defer st.reset()
@@ -171,6 +173,13 @@ func (st *TxnState) Commit(ctx context.Context) error {
 	//	return kv.ErrRetryable
 	// }
 
+	// mockCommitRetryForAutoID is used to mock an commit retry for adjustAutoIncrementDatum.
+	// gofail: var mockCommitRetryForAutoID bool
+	// if mockCommitRetryForAutoID && !hasMockAutoIDRetry {
+	//  hasMockAutoIDRetry = true
+	//	return kv.ErrRetryable
+	// }
+
 	return errors.Trace(st.Transaction.Commit(ctx))
 }