make tidb_disable_txn_auto_retry as it used to be (#10339)

Signed-off-by: Shuaipeng Yu <[email protected]>

session/session.go

@@ -405,7 +405,7 @@ func (s *session) doCommitWithRetry(ctx context.Context) error {
 			// For autocommit single statement transactions, the history count is always 1.
 			// For explicit transactions, the statement count is more than 1.
 			history := GetHistory(s)
-			if history.Count() > 1 && strings.Contains(err.Error(), util.WriteConflictMarker) {
+			if history.Count() > 1 {
 				commitRetryLimit = 0
 			}
 		}

session/session_test.go

@@ -2421,12 +2421,12 @@ func (s *testSchemaSuite) TestDisableTxnAutoRetry(c *C) {
 	tk2.MustExec("alter table no_retry add index idx(id)")
 	tk2.MustQuery("select * from no_retry").Check(testkit.Rows("8"))
 	tk1.MustExec("update no_retry set id = 10")
-	tk1.MustExec("commit")
-	tk2.MustQuery("select * from no_retry").Check(testkit.Rows("10"))
+	_, err = tk1.Se.Execute(context.Background(), "commit")
+	c.Assert(err, NotNil)
 
 	// set autocommit to begin and commit
 	tk1.MustExec("set autocommit = 0")
-	tk1.MustQuery("select * from no_retry").Check(testkit.Rows("10"))
+	tk1.MustQuery("select * from no_retry").Check(testkit.Rows("8"))
 	tk2.MustExec("update no_retry set id = 11")
 	tk1.MustExec("update no_retry set id = 12")
 	_, err = tk1.Se.Execute(context.Background(), "set autocommit = 1")