From b2f1a75ac61c1239f4c0a514acb913b386472a00 Mon Sep 17 00:00:00 2001
From: arnaucube <root@arnaucube.com>
Date: Tue, 19 Jan 2021 13:56:32 +0100
Subject: [PATCH] Fix CoordIdxs fees duplicated

Fix #483
---
 txprocessor/txprocessor.go      |  16 +++++
 txprocessor/txprocessor_test.go | 101 ++++++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+)

diff --git a/txprocessor/txprocessor.go b/txprocessor/txprocessor.go
index 38de86a..7e5fcee 100644
--- a/txprocessor/txprocessor.go
+++ b/txprocessor/txprocessor.go
@@ -233,6 +233,22 @@ func (tp *TxProcessor) ProcessTxs(coordIdxs []common.Idx, l1usertxs, l1coordinat
 		}
 	}
 
+	// remove repeated CoordIdxs that are for the same TokenID (use the
+	// first occurrence)
+	usedCoordTokenIDs := make(map[common.TokenID]bool)
+	var filteredCoordIdxs []common.Idx
+	for i := 0; i < len(coordIdxs); i++ {
+		accCoord, err := tp.s.GetAccount(coordIdxs[i])
+		if err != nil {
+			return nil, tracerr.Wrap(err)
+		}
+		if !usedCoordTokenIDs[accCoord.TokenID] {
+			usedCoordTokenIDs[accCoord.TokenID] = true
+			filteredCoordIdxs = append(filteredCoordIdxs, coordIdxs[i])
+		}
+	}
+	coordIdxs = filteredCoordIdxs
+
 	tp.AccumulatedFees = make(map[common.Idx]*big.Int)
 	for _, idx := range coordIdxs {
 		tp.AccumulatedFees[idx] = big.NewInt(0)
diff --git a/txprocessor/txprocessor_test.go b/txprocessor/txprocessor_test.go
index 1386849..9d9ec48 100644
--- a/txprocessor/txprocessor_test.go
+++ b/txprocessor/txprocessor_test.go
@@ -25,6 +25,12 @@ func checkBalance(t *testing.T, tc *til.Context, sdb *statedb.StateDB, username
 	assert.Equal(t, expected, acc.Balance.String())
 }
 
+func checkBalanceByIdx(t *testing.T, sdb *statedb.StateDB, idx common.Idx, expected string) {
+	acc, err := sdb.GetAccount(idx)
+	require.NoError(t, err)
+	assert.Equal(t, expected, acc.Balance.String())
+}
+
 func TestComputeEffectiveAmounts(t *testing.T) {
 	dir, err := ioutil.TempDir("", "tmpdb")
 	require.NoError(t, err)
@@ -688,3 +694,98 @@ func TestCreateAccountDepositMaxValue(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, daMax1BI, acc.Balance)
 }
+
+func initTestMultipleCoordIdxForTokenID(t *testing.T) (*TxProcessor, *til.Context, []common.BlockData) {
+	dir, err := ioutil.TempDir("", "tmpdb")
+	require.NoError(t, err)
+	defer assert.NoError(t, os.RemoveAll(dir))
+
+	sdb, err := statedb.NewStateDB(dir, 128, statedb.TypeBatchBuilder, 32)
+	assert.NoError(t, err)
+
+	chainID := uint16(1)
+
+	// generate test transactions from test.SetBlockchain0 code
+	tc := til.NewContext(chainID, common.RollupConstMaxL1UserTx)
+
+	set := `
+		Type: Blockchain
+
+		CreateAccountDeposit(0) A: 200
+
+		> batchL1 // freeze L1User{1}
+
+		CreateAccountCoordinator(0) Coord
+		CreateAccountCoordinator(0) B
+
+		Transfer(0) A-B: 100 (126)
+
+		> batchL1 // forge L1User{1}, forge L1Coord{4}, forge L2{2}
+		> block
+	`
+	blocks, err := tc.GenerateBlocks(set)
+	require.NoError(t, err)
+
+	config := Config{
+		NLevels:  32,
+		MaxFeeTx: 64,
+		MaxTx:    512,
+		MaxL1Tx:  16,
+		ChainID:  chainID,
+	}
+	tp := NewTxProcessor(sdb, config)
+	// batch1
+	_, err = tp.ProcessTxs(nil, nil, nil, nil) // to simulate the first batch from the Til set
+	require.NoError(t, err)
+
+	return tp, tc, blocks
+}
+
+func TestMultipleCoordIdxForTokenID(t *testing.T) {
+	// Check that ProcessTxs always uses the first occurrence of the
+	// CoordIdx for each TokenID
+
+	coordIdxs := []common.Idx{257, 257, 257}
+	tp, tc, blocks := initTestMultipleCoordIdxForTokenID(t)
+	l1UserTxs := til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[1].Batch.ForgeL1TxsNum])
+	l1CoordTxs := blocks[0].Rollup.Batches[1].L1CoordinatorTxs
+	l1CoordTxs = append(l1CoordTxs, l1CoordTxs[0]) // duplicate the CoordAccount for TokenID=0
+	l2Txs := common.L2TxsToPoolL2Txs(blocks[0].Rollup.Batches[1].L2Txs)
+	_, err := tp.ProcessTxs(coordIdxs, l1UserTxs, l1CoordTxs, l2Txs)
+	require.NoError(t, err)
+
+	checkBalanceByIdx(t, tp.s, 256, "90")  // A
+	checkBalanceByIdx(t, tp.s, 257, "10")  // Coord0
+	checkBalanceByIdx(t, tp.s, 258, "100") // B
+	checkBalanceByIdx(t, tp.s, 259, "0")   // Coord0
+
+	// reset StateDB values
+	coordIdxs = []common.Idx{259, 257}
+	tp, tc, blocks = initTestMultipleCoordIdxForTokenID(t)
+	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[1].Batch.ForgeL1TxsNum])
+	l1CoordTxs = blocks[0].Rollup.Batches[1].L1CoordinatorTxs
+	l1CoordTxs = append(l1CoordTxs, l1CoordTxs[0]) // duplicate the CoordAccount for TokenID=0
+	l2Txs = common.L2TxsToPoolL2Txs(blocks[0].Rollup.Batches[1].L2Txs)
+	_, err = tp.ProcessTxs(coordIdxs, l1UserTxs, l1CoordTxs, l2Txs)
+	require.NoError(t, err)
+
+	checkBalanceByIdx(t, tp.s, 256, "90")  // A
+	checkBalanceByIdx(t, tp.s, 257, "0")   // Coord0
+	checkBalanceByIdx(t, tp.s, 258, "100") // B
+	checkBalanceByIdx(t, tp.s, 259, "10")  // Coord0
+
+	// reset StateDB values
+	coordIdxs = []common.Idx{257, 259}
+	tp, tc, blocks = initTestMultipleCoordIdxForTokenID(t)
+	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[1].Batch.ForgeL1TxsNum])
+	l1CoordTxs = blocks[0].Rollup.Batches[1].L1CoordinatorTxs
+	l1CoordTxs = append(l1CoordTxs, l1CoordTxs[0]) // duplicate the CoordAccount for TokenID=0
+	l2Txs = common.L2TxsToPoolL2Txs(blocks[0].Rollup.Batches[1].L2Txs)
+	_, err = tp.ProcessTxs(coordIdxs, l1UserTxs, l1CoordTxs, l2Txs)
+	require.NoError(t, err)
+
+	checkBalanceByIdx(t, tp.s, 256, "90")  // A
+	checkBalanceByIdx(t, tp.s, 257, "10")  // Coord0
+	checkBalanceByIdx(t, tp.s, 258, "100") // B
+	checkBalanceByIdx(t, tp.s, 259, "0")   // Coord0
+}