txn: fix txn status in rolback response (#4794)

Use Active status in rollback response, and txn client panic after check the txn status in response

Approved by: @lni, @reusee

pkg/txn/service/service_cn_handler.go

@@ -331,8 +331,9 @@ func (s *service) Rollback(ctx context.Context, request *txn.TxnRequest, respons
 
 	response.Txn = &newTxn
 	newTxn.DNShards = request.Txn.DNShards
-
 	s.startAsyncRollbackTask(newTxn)
+
+	response.Txn.Status = txn.TxnStatus_Aborted
 	return nil
 }
 

pkg/txn/service/service_cn_handler_test.go

@@ -561,7 +561,11 @@ func TestRollback(t *testing.T) {
 	w2 := addTestWaiter(t, s2, wTxn, txn.TxnStatus_Aborted)
 	defer w2.close()
 
-	checkResponses(t, rollbackWriteData(t, sender, wTxn))
+	responses := rollbackWriteData(t, sender, wTxn)
+	checkResponses(t, responses)
+	for _, resp := range responses {
+		assert.Equal(t, txn.TxnStatus_Aborted, resp.Txn.Status)
+	}
 
 	checkWaiter(t, w1, txn.TxnStatus_Aborted)
 	checkWaiter(t, w2, txn.TxnStatus_Aborted)