TxSel avoid L1CoordTx for L2Tx that have a L1UserTx in the frozen queue

For the L2Txs of TransferToEthAddr & TransferToBJJ for a not-yet
existing accounts, in the TxSelector check if L2Tx receiver account will
be created by a L1UserFrozenTxs (in the next batch, the current frozen
queue). In that case, the L2Tx will be discarded at the current batch,
even if there is an AccountCreationAuth for the account, as there is a
L1UserTx in the frozen queue that will create the receiver Account.  The
L2Tx is discarded to avoid the Coordinator creating a new
L1CoordinatorTx to create the receiver account, which will be also
created in the next batch from the L1UserFrozenTx, ending with the user
having 2 different accounts for the same TokenID.
The double account creation is supported by the Hermez zkRollup
specification, but it was decided to mitigate it at the TxSelector level
for the explained cases.

common/l1tx.go

@@ -22,7 +22,7 @@ type L1Tx struct {
 	// 	- L1UserTx: 0
 	// 	- L1CoordinatorTx: 1
 	TxID TxID `meddler:"id"`
-	// ToForgeL1TxsNum indicates in which the tx was forged / will be forged
+	// ToForgeL1TxsNum indicates in which L1UserTx queue the tx was forged / will be forged
 	ToForgeL1TxsNum *int64 `meddler:"to_forge_l1_txs_num"`
 	Position        int    `meddler:"position"`
 	// UserOrigin is set to true if the tx was originated by a user, false if it was

coordinator/pipeline.go

@@ -523,15 +523,30 @@ func (p *Pipeline) forgeBatch(batchNum common.BatchNum) (batchInfo *BatchInfo,
 		if err != nil {
 			return nil, nil, tracerr.Wrap(err)
 		}
+		// l1UserFutureTxs are the l1UserTxs that are not being forged
+		// in the next batch, but that are also in the queue for the
+		// future batches
+		l1UserFutureTxs, err := p.historyDB.GetUnforgedL1UserFutureTxs(p.state.lastForgeL1TxsNum + 1)
+		if err != nil {
+			return nil, nil, tracerr.Wrap(err)
+		}
+
 		coordIdxs, auths, l1UserTxs, l1CoordTxs, poolL2Txs, discardedL2Txs, err =
-			p.txSelector.GetL1L2TxSelection(p.cfg.TxProcessorConfig, _l1UserTxs)
+			p.txSelector.GetL1L2TxSelection(p.cfg.TxProcessorConfig, _l1UserTxs, l1UserFutureTxs)
 		if err != nil {
 			return nil, nil, tracerr.Wrap(err)
 		}
 	} else {
+		// get l1UserFutureTxs which are all the l1 pending in all the
+		// queues
+		l1UserFutureTxs, err := p.historyDB.GetUnforgedL1UserFutureTxs(p.state.lastForgeL1TxsNum) //nolint:gomnd
+		if err != nil {
+			return nil, nil, tracerr.Wrap(err)
+		}
+
 		// 2b: only L2 txs
 		coordIdxs, auths, l1CoordTxs, poolL2Txs, discardedL2Txs, err =
-			p.txSelector.GetL2TxSelection(p.cfg.TxProcessorConfig)
+			p.txSelector.GetL2TxSelection(p.cfg.TxProcessorConfig, l1UserFutureTxs)
 		if err != nil {
 			return nil, nil, tracerr.Wrap(err)
 		}

db/historydb/historydb.go

@@ -751,6 +751,24 @@ func (hdb *HistoryDB) GetUnforgedL1UserTxs(toForgeL1TxsNum int64) ([]common.L1Tx
 	return db.SlicePtrsToSlice(txs).([]common.L1Tx), tracerr.Wrap(err)
 }
 
+// GetUnforgedL1UserFutureTxs gets L1 User Txs to be forged after the L1Batch
+// with toForgeL1TxsNum (in one of the future batches, not in the next one).
+func (hdb *HistoryDB) GetUnforgedL1UserFutureTxs(toForgeL1TxsNum int64) ([]common.L1Tx, error) {
+	var txs []*common.L1Tx
+	err := meddler.QueryAll(
+		hdb.dbRead, &txs, // only L1 user txs can have batch_num set to null
+		`SELECT tx.id, tx.to_forge_l1_txs_num, tx.position, tx.user_origin,
+		tx.from_idx, tx.from_eth_addr, tx.from_bjj, tx.to_idx, tx.token_id,
+		tx.amount, NULL AS effective_amount,
+		tx.deposit_amount, NULL AS effective_deposit_amount,
+		tx.eth_block_num, tx.type, tx.batch_num
+		FROM tx WHERE batch_num IS NULL AND to_forge_l1_txs_num > $1
+		ORDER BY position;`,
+		toForgeL1TxsNum,
+	)
+	return db.SlicePtrsToSlice(txs).([]common.L1Tx), tracerr.Wrap(err)
+}
+
 // GetUnforgedL1UserTxsCount returns the count of unforged L1Txs (either in
 // open or frozen queues that are not yet forged)
 func (hdb *HistoryDB) GetUnforgedL1UserTxsCount() (int, error) {

db/historydb/historydb_test.go

@@ -699,34 +699,55 @@ func TestGetUnforgedL1UserTxs(t *testing.T) {
 		CreateAccountDeposit(1) B: 5
 		CreateAccountDeposit(1) C: 5
 		CreateAccountDeposit(1) D: 5
-
 		> block
+
+		> batchL1
+		> block
+
+		CreateAccountDeposit(1) E: 5
+		CreateAccountDeposit(1) F: 5
+		> block
+
 	`
 	tc := til.NewContext(uint16(0), 128)
 	blocks, err := tc.GenerateBlocks(set)
 	require.NoError(t, err)
 	// Sanity check
-	require.Equal(t, 1, len(blocks))
+	require.Equal(t, 3, len(blocks))
 	require.Equal(t, 5, len(blocks[0].Rollup.L1UserTxs))
 
-	toForgeL1TxsNum := int64(1)
-
 	for i := range blocks {
 		err = historyDB.AddBlockSCData(&blocks[i])
 		require.NoError(t, err)
 	}
 
-	l1UserTxs, err := historyDB.GetUnforgedL1UserTxs(toForgeL1TxsNum)
+	l1UserTxs, err := historyDB.GetUnforgedL1UserFutureTxs(0)
+	require.NoError(t, err)
+	assert.Equal(t, 7, len(l1UserTxs))
+
+	l1UserTxs, err = historyDB.GetUnforgedL1UserTxs(1)
 	require.NoError(t, err)
 	assert.Equal(t, 5, len(l1UserTxs))
 	assert.Equal(t, blocks[0].Rollup.L1UserTxs, l1UserTxs)
 
+	l1UserTxs, err = historyDB.GetUnforgedL1UserFutureTxs(1)
+	require.NoError(t, err)
+	assert.Equal(t, 2, len(l1UserTxs))
+
 	count, err := historyDB.GetUnforgedL1UserTxsCount()
 	require.NoError(t, err)
-	assert.Equal(t, 5, count)
+	assert.Equal(t, 7, count)
+
+	l1UserTxs, err = historyDB.GetUnforgedL1UserTxs(2)
+	require.NoError(t, err)
+	assert.Equal(t, 2, len(l1UserTxs))
+
+	l1UserTxs, err = historyDB.GetUnforgedL1UserFutureTxs(2)
+	require.NoError(t, err)
+	assert.Equal(t, 0, len(l1UserTxs))
 
 	// No l1UserTxs for this toForgeL1TxsNum
-	l1UserTxs, err = historyDB.GetUnforgedL1UserTxs(2)
+	l1UserTxs, err = historyDB.GetUnforgedL1UserTxs(3)
 	require.NoError(t, err)
 	assert.Equal(t, 0, len(l1UserTxs))
 }

test/zkproof/flows_test.go

@@ -156,7 +156,7 @@ func TestTxSelectorBatchBuilderZKInputsMinimumFlow0(t *testing.T) {
 		}
 		// TxSelector select the transactions for the next Batch
 		coordIdxs, _, oL1UserTxs, oL1CoordTxs, oL2Txs, _, err :=
-			txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs)
+			txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs, nil)
 		require.NoError(t, err)
 		// BatchBuilder build Batch
 		zki, err := bb.BuildBatch(coordIdxs, configBatch, oL1UserTxs, oL1CoordTxs, oL2Txs)
@@ -180,7 +180,7 @@ func TestTxSelectorBatchBuilderZKInputsMinimumFlow0(t *testing.T) {
 	l1UserTxs := til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[6].Batch.ForgeL1TxsNum])
 	// TxSelector select the transactions for the next Batch
 	coordIdxs, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
-		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs)
+		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs, nil)
 	require.NoError(t, err)
 	// BatchBuilder build Batch
 	zki, err := bb.BuildBatch(coordIdxs, configBatch, oL1UserTxs, oL1CoordTxs, oL2Txs)
@@ -209,7 +209,7 @@ func TestTxSelectorBatchBuilderZKInputsMinimumFlow0(t *testing.T) {
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[7].Batch.ForgeL1TxsNum])
 	// TxSelector select the transactions for the next Batch
 	coordIdxs, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs)
+		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs, nil)
 	require.NoError(t, err)
 	// BatchBuilder build Batch
 	zki, err = bb.BuildBatch(coordIdxs, configBatch, oL1UserTxs, oL1CoordTxs, oL2Txs)
@@ -236,7 +236,7 @@ func TestTxSelectorBatchBuilderZKInputsMinimumFlow0(t *testing.T) {
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[1].Rollup.Batches[0].Batch.ForgeL1TxsNum])
 	// TxSelector select the transactions for the next Batch
 	coordIdxs, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs)
+		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs, nil)
 	require.NoError(t, err)
 	// BatchBuilder build Batch
 	zki, err = bb.BuildBatch(coordIdxs, configBatch, oL1UserTxs, oL1CoordTxs, oL2Txs)
@@ -256,7 +256,7 @@ func TestTxSelectorBatchBuilderZKInputsMinimumFlow0(t *testing.T) {
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[1].Rollup.Batches[1].Batch.ForgeL1TxsNum])
 	// TxSelector select the transactions for the next Batch
 	coordIdxs, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs)
+		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs, nil)
 	require.NoError(t, err)
 	// BatchBuilder build Batch
 	zki, err = bb.BuildBatch(coordIdxs, configBatch, oL1UserTxs, oL1CoordTxs, oL2Txs)
@@ -319,7 +319,7 @@ func TestZKInputsExitWithFee0(t *testing.T) {
 	// TxSelector select the transactions for the next Batch
 	l1UserTxs := til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[1].Batch.ForgeL1TxsNum])
 	coordIdxs, _, oL1UserTxs, oL1CoordTxs, oL2Txs, _, err :=
-		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs)
+		txsel.GetL1L2TxSelection(txprocConfig, l1UserTxs, nil)
 	require.NoError(t, err)
 	// BatchBuilder build Batch
 	zki, err := bb.BuildBatch(coordIdxs, configBatch, oL1UserTxs, oL1CoordTxs, oL2Txs)
@@ -342,7 +342,7 @@ func TestZKInputsExitWithFee0(t *testing.T) {
 	require.NoError(t, err)
 	addL2Txs(t, l2DBTxSel, l2Txs) // Add L2s to TxSelector.L2DB
 	coordIdxs, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
-		txsel.GetL1L2TxSelection(txprocConfig, nil)
+		txsel.GetL1L2TxSelection(txprocConfig, nil, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 1, len(coordIdxs))
 	assert.Equal(t, 0, len(oL1UserTxs))

txselector/txselector.go

@@ -85,7 +85,7 @@ func (txsel *TxSelector) getCoordIdx(tokenID common.TokenID) (common.Idx, error)
 func (txsel *TxSelector) coordAccountForTokenID(l1CoordinatorTxs []common.L1Tx,
 	tokenID common.TokenID, positionL1 int) (*common.L1Tx, int, error) {
 	// check if CoordinatorAccount for TokenID is already pending to create
-	if checkAlreadyPendingToCreate(l1CoordinatorTxs, tokenID,
+	if checkPendingToCreateL1CoordTx(l1CoordinatorTxs, tokenID,
 		txsel.coordAccount.Addr, txsel.coordAccount.BJJ) {
 		return nil, positionL1, nil
 	}
@@ -122,11 +122,12 @@ func (txsel *TxSelector) coordAccountForTokenID(l1CoordinatorTxs []common.L1Tx,
 // but there is a transactions to them and the authorization of account
 // creation exists. The L1UserTxs, L1CoordinatorTxs, PoolL2Txs that will be
 // included in the next batch.
-func (txsel *TxSelector) GetL2TxSelection(selectionConfig txprocessor.Config) ([]common.Idx,
+func (txsel *TxSelector) GetL2TxSelection(selectionConfig txprocessor.Config, l1UserFutureTxs []common.L1Tx) ([]common.Idx,
 	[][]byte, []common.L1Tx, []common.PoolL2Tx, []common.PoolL2Tx, error) {
 	metric.GetL2TxSelection.Inc()
 	coordIdxs, accCreationAuths, _, l1CoordinatorTxs, l2Txs,
-		discardedL2Txs, err := txsel.getL1L2TxSelection(selectionConfig, []common.L1Tx{})
+		discardedL2Txs, err := txsel.getL1L2TxSelection(selectionConfig,
+		[]common.L1Tx{}, l1UserFutureTxs)
 	return coordIdxs, accCreationAuths, l1CoordinatorTxs, l2Txs,
 		discardedL2Txs, tracerr.Wrap(err)
 }
@@ -140,11 +141,11 @@ func (txsel *TxSelector) GetL2TxSelection(selectionConfig txprocessor.Config) ([
 // creation exists. The L1UserTxs, L1CoordinatorTxs, PoolL2Txs that will be
 // included in the next batch.
 func (txsel *TxSelector) GetL1L2TxSelection(selectionConfig txprocessor.Config,
-	l1UserTxs []common.L1Tx) ([]common.Idx, [][]byte, []common.L1Tx,
+	l1UserTxs, l1UserFutureTxs []common.L1Tx) ([]common.Idx, [][]byte, []common.L1Tx,
 	[]common.L1Tx, []common.PoolL2Tx, []common.PoolL2Tx, error) {
 	metric.GetL1L2TxSelection.Inc()
 	coordIdxs, accCreationAuths, l1UserTxs, l1CoordinatorTxs, l2Txs,
-		discardedL2Txs, err := txsel.getL1L2TxSelection(selectionConfig, l1UserTxs)
+		discardedL2Txs, err := txsel.getL1L2TxSelection(selectionConfig, l1UserTxs, l1UserFutureTxs)
 	return coordIdxs, accCreationAuths, l1UserTxs, l1CoordinatorTxs, l2Txs,
 		discardedL2Txs, tracerr.Wrap(err)
 }
@@ -158,7 +159,7 @@ func (txsel *TxSelector) GetL1L2TxSelection(selectionConfig txprocessor.Config,
 // creation exists. The L1UserTxs, L1CoordinatorTxs, PoolL2Txs that will be
 // included in the next batch.
 func (txsel *TxSelector) getL1L2TxSelection(selectionConfig txprocessor.Config,
-	l1UserTxs []common.L1Tx) ([]common.Idx, [][]byte, []common.L1Tx,
+	l1UserTxs, l1UserFutureTxs []common.L1Tx) ([]common.Idx, [][]byte, []common.L1Tx,
 	[]common.L1Tx, []common.PoolL2Tx, []common.PoolL2Tx, error) {
 	// WIP.0: the TxSelector is not optimized and will need a redesign. The
 	// current version is implemented in order to have a functional
@@ -235,7 +236,7 @@ func (txsel *TxSelector) getL1L2TxSelection(selectionConfig txprocessor.Config,
 	var validTxs, discardedL2Txs []common.PoolL2Tx
 	l2TxsForgable = sortL2Txs(l2TxsForgable)
 	accAuths, l1CoordinatorTxs, validTxs, discardedL2Txs, err =
-		txsel.processL2Txs(tp, selectionConfig, len(l1UserTxs),
+		txsel.processL2Txs(tp, selectionConfig, len(l1UserTxs), l1UserFutureTxs,
 			l2TxsForgable, validTxs, discardedL2Txs)
 	if err != nil {
 		return nil, nil, nil, nil, nil, nil, tracerr.Wrap(err)
@@ -249,8 +250,8 @@ func (txsel *TxSelector) getL1L2TxSelection(selectionConfig txprocessor.Config,
 		var l1CoordinatorTxs2 []common.L1Tx
 		accAuths2, l1CoordinatorTxs2, validTxs, discardedL2Txs, err =
 			txsel.processL2Txs(tp, selectionConfig,
-				len(l1UserTxs)+len(l1CoordinatorTxs), l2TxsNonForgable,
+				len(l1UserTxs)+len(l1CoordinatorTxs), l1UserFutureTxs,
-				validTxs, discardedL2Txs)
+				l2TxsNonForgable, validTxs, discardedL2Txs)
 		if err != nil {
 			return nil, nil, nil, nil, nil, nil, tracerr.Wrap(err)
 		}
@@ -331,8 +332,9 @@ func (txsel *TxSelector) getL1L2TxSelection(selectionConfig txprocessor.Config,
 }
 
 func (txsel *TxSelector) processL2Txs(tp *txprocessor.TxProcessor,
-	selectionConfig txprocessor.Config, nL1Txs int, l2Txs, validTxs, discardedL2Txs []common.PoolL2Tx) (
+	selectionConfig txprocessor.Config, nL1Txs int, l1UserFutureTxs []common.L1Tx,
-	[][]byte, []common.L1Tx, []common.PoolL2Tx, []common.PoolL2Tx, error) {
+	l2Txs, validTxs, discardedL2Txs []common.PoolL2Tx) ([][]byte, []common.L1Tx,
+	[]common.PoolL2Tx, []common.PoolL2Tx, error) {
 	var l1CoordinatorTxs []common.L1Tx
 	positionL1 := nL1Txs
 	var accAuths [][]byte
@@ -434,7 +436,8 @@ func (txsel *TxSelector) processL2Txs(tp *txprocessor.TxProcessor,
 		if l2Txs[i].ToIdx == 0 { // ToEthAddr/ToBJJ case
 			validL2Tx, l1CoordinatorTx, accAuth, err :=
 				txsel.processTxToEthAddrBJJ(validTxs, selectionConfig,
-					nL1Txs, l1CoordinatorTxs, positionL1, l2Txs[i])
+					nL1Txs, l1UserFutureTxs, l1CoordinatorTxs,
+					positionL1, l2Txs[i])
 			if err != nil {
 				log.Debugw("txsel.processTxToEthAddrBJJ", "err", err)
 				// Discard L2Tx, and update Info parameter of
@@ -574,18 +577,35 @@ func (txsel *TxSelector) processL2Txs(tp *txprocessor.TxProcessor,
 // l1CoordinatorTxs array, and then the PoolL2Tx is added into the validTxs
 // array.
 func (txsel *TxSelector) processTxToEthAddrBJJ(validTxs []common.PoolL2Tx,
-	selectionConfig txprocessor.Config, nL1UserTxs int, l1CoordinatorTxs []common.L1Tx,
+	selectionConfig txprocessor.Config, nL1UserTxs int, l1UserFutureTxs,
-	positionL1 int, l2Tx common.PoolL2Tx) (*common.PoolL2Tx, *common.L1Tx,
+	l1CoordinatorTxs []common.L1Tx, positionL1 int, l2Tx common.PoolL2Tx) (
-	*common.AccountCreationAuth, error) {
+	*common.PoolL2Tx, *common.L1Tx, *common.AccountCreationAuth, error) {
 	// if L2Tx needs a new L1CoordinatorTx of CreateAccount type, and a
 	// previous L2Tx in the current process already created a
 	// L1CoordinatorTx of this type, in the DB there still seem that needs
 	// to create a new L1CoordinatorTx, but as is already created, the tx
 	// is valid
-	if checkAlreadyPendingToCreate(l1CoordinatorTxs, l2Tx.TokenID, l2Tx.ToEthAddr, l2Tx.ToBJJ) {
+	if checkPendingToCreateL1CoordTx(l1CoordinatorTxs, l2Tx.TokenID, l2Tx.ToEthAddr, l2Tx.ToBJJ) {
 		return &l2Tx, nil, nil, nil
 	}
 
+	// check if L2Tx receiver account will be created by a L1UserFutureTxs
+	// (in the next batch, the current frozen queue). In that case, the L2Tx
+	// will be discarded at the current batch, even if there is an
+	// AccountCreationAuth for the account, as there is a L1UserTx in the
+	// frozen queue that will create the receiver Account.  The L2Tx is
+	// discarded to avoid the Coordinator creating a new L1CoordinatorTx to
+	// create the receiver account, which will be also created in the next
+	// batch from the L1UserFutureTx, ending with the user having 2
+	// different accounts for the same TokenID. The double account creation
+	// is supported by the Hermez zkRollup specification, but it was decided
+	// to mitigate it at the TxSelector level for the explained cases.
+	if checkPendingToCreateFutureTxs(l1UserFutureTxs, l2Tx.TokenID, l2Tx.ToEthAddr, l2Tx.ToBJJ) {
+		return nil, nil, nil, fmt.Errorf("L2Tx discarded at the current batch, as the" +
+			" receiver account does not exist yet, and there is a L1UserTx that" +
+			" will create that account in a future batch.")
+	}
+
 	var l1CoordinatorTx *common.L1Tx
 	var accAuth *common.AccountCreationAuth
 	if l2Tx.ToEthAddr != common.EmptyAddr && l2Tx.ToEthAddr != common.FFAddr {
@@ -688,7 +708,7 @@ func (txsel *TxSelector) processTxToEthAddrBJJ(validTxs []common.PoolL2Tx,
 	return &l2Tx, l1CoordinatorTx, accAuth, nil
 }
 
-func checkAlreadyPendingToCreate(l1CoordinatorTxs []common.L1Tx, tokenID common.TokenID,
+func checkPendingToCreateL1CoordTx(l1CoordinatorTxs []common.L1Tx, tokenID common.TokenID,
 	addr ethCommon.Address, bjj babyjub.PublicKeyComp) bool {
 	for i := 0; i < len(l1CoordinatorTxs); i++ {
 		if l1CoordinatorTxs[i].FromEthAddr == addr &&
@@ -700,6 +720,23 @@ func checkAlreadyPendingToCreate(l1CoordinatorTxs []common.L1Tx, tokenID common.
 	return false
 }
 
+func checkPendingToCreateFutureTxs(l1UserFutureTxs []common.L1Tx, tokenID common.TokenID,
+	addr ethCommon.Address, bjj babyjub.PublicKeyComp) bool {
+	for i := 0; i < len(l1UserFutureTxs); i++ {
+		if l1UserFutureTxs[i].FromEthAddr == addr &&
+			l1UserFutureTxs[i].TokenID == tokenID &&
+			l1UserFutureTxs[i].FromBJJ == bjj {
+			return true
+		}
+		if l1UserFutureTxs[i].FromEthAddr == addr &&
+			l1UserFutureTxs[i].TokenID == tokenID &&
+			common.EmptyBJJComp == bjj {
+			return true
+		}
+	}
+	return false
+}
+
 // sortL2Txs sorts the PoolL2Txs by AbsoluteFee and then by Nonce
 func sortL2Txs(l2Txs []common.PoolL2Tx) []common.PoolL2Tx {
 	// Sort by absolute fee with SliceStable, so that txs with same

txselector/txselector_test.go

@@ -182,7 +182,7 @@ func TestGetL2TxSelectionMinimumFlow0(t *testing.T) {
 	log.Debug("block:0 batch:1")
 	l1UserTxs := []common.L1Tx{}
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, _, err :=
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 0, len(oL1UserTxs))
 	assert.Equal(t, 0, len(oL1CoordTxs))
@@ -193,7 +193,7 @@ func TestGetL2TxSelectionMinimumFlow0(t *testing.T) {
 	log.Debug("block:0 batch:2")
 	l1UserTxs = []common.L1Tx{}
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, _, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 0, len(oL1UserTxs))
 	assert.Equal(t, 0, len(oL1CoordTxs))
@@ -204,7 +204,7 @@ func TestGetL2TxSelectionMinimumFlow0(t *testing.T) {
 	log.Debug("block:0 batch:3")
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[2].Batch.ForgeL1TxsNum])
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, _, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 2, len(oL1UserTxs))
 	assert.Equal(t, 0, len(oL1CoordTxs))
@@ -217,7 +217,7 @@ func TestGetL2TxSelectionMinimumFlow0(t *testing.T) {
 	log.Debug("block:0 batch:4")
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[3].Batch.ForgeL1TxsNum])
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, _, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 1, len(oL1UserTxs))
 	assert.Equal(t, 0, len(oL1CoordTxs))
@@ -231,7 +231,7 @@ func TestGetL2TxSelectionMinimumFlow0(t *testing.T) {
 	log.Debug("block:0 batch:5")
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[4].Batch.ForgeL1TxsNum])
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, _, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 0, len(oL1UserTxs))
 	assert.Equal(t, 0, len(oL1CoordTxs))
@@ -245,7 +245,7 @@ func TestGetL2TxSelectionMinimumFlow0(t *testing.T) {
 	log.Debug("block:0 batch:6")
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[5].Batch.ForgeL1TxsNum])
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, _, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 1, len(oL1UserTxs))
 	assert.Equal(t, 0, len(oL1CoordTxs))
@@ -279,7 +279,7 @@ func TestGetL2TxSelectionMinimumFlow0(t *testing.T) {
 	assert.True(t, l2TxsFromDB[1].VerifySignature(chainID, tc.Users["B"].BJJ.Public().Compress()))
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[6].Batch.ForgeL1TxsNum])
 	coordIdxs, accAuths, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, []common.Idx{261, 263}, coordIdxs)
 	assert.Equal(t, txsel.coordAccount.AccountCreationAuth, accAuths[0])
@@ -328,7 +328,7 @@ func TestGetL2TxSelectionMinimumFlow0(t *testing.T) {
 	assert.True(t, l2TxsFromDB[3].VerifySignature(chainID, tc.Users["A"].BJJ.Public().Compress()))
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[7].Batch.ForgeL1TxsNum])
 	coordIdxs, accAuths, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, []common.Idx{261, 263}, coordIdxs)
 	assert.Equal(t, 0, len(accAuths))
@@ -372,7 +372,7 @@ func TestGetL2TxSelectionMinimumFlow0(t *testing.T) {
 	assert.True(t, l2TxsFromDB[1].VerifySignature(chainID, tc.Users["B"].BJJ.Public().Compress()))
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[1].Rollup.Batches[0].Batch.ForgeL1TxsNum])
 	coordIdxs, accAuths, oL1UserTxs, oL1CoordTxs, oL2Txs, _, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, []common.Idx{263}, coordIdxs)
 	assert.Equal(t, 0, len(accAuths))
@@ -434,7 +434,7 @@ func TestPoolL2TxsWithoutEnoughBalance(t *testing.T) {
 	}
 	// batch1
 	l1UserTxs := []common.L1Tx{}
-	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	// 1st TransferToEthAddr
 	expectedTxID0 := "0x028847b86613c0b70be18c8622119ed045b42e4e47d7938fa90bb3d1dc14928965"
@@ -456,7 +456,7 @@ func TestPoolL2TxsWithoutEnoughBalance(t *testing.T) {
 
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[1].Batch.ForgeL1TxsNum])
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 3, len(oL1UserTxs))
 	assert.Equal(t, 0, len(oL1CoordTxs))
@@ -481,7 +481,7 @@ func TestPoolL2TxsWithoutEnoughBalance(t *testing.T) {
 
 	l1UserTxs = []common.L1Tx{}
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 0, len(oL1UserTxs))
 	assert.Equal(t, 0, len(oL1CoordTxs))
@@ -500,7 +500,7 @@ func TestPoolL2TxsWithoutEnoughBalance(t *testing.T) {
 	// initial PoolExit, which now is valid as B has enough Balance
 	l1UserTxs = []common.L1Tx{}
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 0, len(oL1UserTxs))
 	assert.Equal(t, 0, len(oL1CoordTxs))
@@ -550,7 +550,7 @@ func TestTransferToBjj(t *testing.T) {
 	// batch1 to freeze L1UserTxs that will create some accounts with
 	// positive balance
 	l1UserTxs := []common.L1Tx{}
-	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 
 	// Transfer is ToBJJ to a BJJ-only account that doesn't exist
@@ -568,7 +568,7 @@ func TestTransferToBjj(t *testing.T) {
 
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[1].Batch.ForgeL1TxsNum])
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 4, len(oL1UserTxs))
 	// We expect the coordinator to add an L1CoordTx to create an account for the recipient of the l2tx
@@ -595,7 +595,7 @@ func TestTransferToBjj(t *testing.T) {
 
 	l1UserTxs = []common.L1Tx{}
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 0, len(oL1UserTxs))
 	// Since the BJJ-only account B already exists, the coordinator doesn't add any L1CoordTxs
@@ -623,7 +623,7 @@ func TestTransferToBjj(t *testing.T) {
 
 	l1UserTxs = []common.L1Tx{}
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 0, len(oL1UserTxs))
 	// We expect the coordinator to add an L1CoordTx to create an account
@@ -678,7 +678,7 @@ func TestTransferManyFromSameAccount(t *testing.T) {
 	}
 	// batch1 to freeze L1UserTxs
 	l1UserTxs := []common.L1Tx{}
-	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 
 	// 8 transfers from the same account
@@ -710,7 +710,7 @@ func TestTransferManyFromSameAccount(t *testing.T) {
 	// transfers from account A
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[1].Batch.ForgeL1TxsNum])
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 3, len(oL1UserTxs))
 	require.Equal(t, 0, len(oL1CoordTxs))
@@ -760,7 +760,7 @@ func TestPoolL2TxInvalidNonces(t *testing.T) {
 	}
 	// batch1 to freeze L1UserTxs
 	l1UserTxs := []common.L1Tx{}
-	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 
 	batchPoolL2 := `
@@ -794,7 +794,7 @@ func TestPoolL2TxInvalidNonces(t *testing.T) {
 
 	// select L1 & L2 txs
 	_, accAuths, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	require.Equal(t, 3, len(oL1UserTxs))
 	require.Equal(t, 0, len(oL1CoordTxs))
@@ -809,7 +809,7 @@ func TestPoolL2TxInvalidNonces(t *testing.T) {
 	// batch 3
 	l1UserTxs = []common.L1Tx{}
 	_, accAuths, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 
 	require.Equal(t, 0, len(oL1UserTxs))
@@ -825,7 +825,7 @@ func TestPoolL2TxInvalidNonces(t *testing.T) {
 	// batch 4
 	l1UserTxs = []common.L1Tx{}
 	_, accAuths, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 
 	require.Equal(t, 0, len(oL1UserTxs))
@@ -873,10 +873,10 @@ func TestProcessL2Selection(t *testing.T) {
 	}
 	// batch1 to freeze L1UserTxs
 	l1UserTxs := []common.L1Tx{}
-	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 
-	// 8 transfers from the same account
+	// 3 transfers from the same account
 	batchPoolL2 := `
 	Type: PoolL2
 	PoolTransfer(0) A-B: 10 (126)
@@ -889,10 +889,10 @@ func TestProcessL2Selection(t *testing.T) {
 
 	// add the PoolL2Txs to the l2DB
 	addL2Txs(t, txsel, poolL2Txs)
-	// batch 2 to crate some accounts with positive balance, and do 8 L2Tx transfers from account A
+	// batch 2 to crate some accounts with positive balance, and do 3 L2Tx transfers from account A
 	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[1].Batch.ForgeL1TxsNum])
 	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	assert.Equal(t, 3, len(oL1UserTxs))
 	require.Equal(t, 0, len(oL1CoordTxs))
@@ -968,7 +968,7 @@ func TestValidTxsWithLowFeeAndInvalidTxsWithHighFee(t *testing.T) {
 	}
 	// batch1 to freeze L1UserTxs
 	l1UserTxs := []common.L1Tx{}
-	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 
 	// batch 2 to crate the accounts (from L1UserTxs)
@@ -976,7 +976,7 @@ func TestValidTxsWithLowFeeAndInvalidTxsWithHighFee(t *testing.T) {
 
 	// select L1 & L2 txs
 	_, accAuths, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 	require.Equal(t, 3, len(oL1UserTxs))
 	require.Equal(t, 0, len(oL1CoordTxs))
@@ -1014,7 +1014,7 @@ func TestValidTxsWithLowFeeAndInvalidTxsWithHighFee(t *testing.T) {
 	addL2Txs(t, txsel, poolL2Txs)
 	l1UserTxs = []common.L1Tx{}
 	_, accAuths, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 
 	require.Equal(t, 0, len(oL1UserTxs))
@@ -1029,7 +1029,7 @@ func TestValidTxsWithLowFeeAndInvalidTxsWithHighFee(t *testing.T) {
 
 	// batch 4. In this Batch, account B has enough balance to send the txs
 	_, accAuths, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
-		txsel.GetL1L2TxSelection(tpc, l1UserTxs)
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, nil)
 	require.NoError(t, err)
 
 	require.Equal(t, 0, len(oL1UserTxs))
@@ -1038,3 +1038,112 @@ func TestValidTxsWithLowFeeAndInvalidTxsWithHighFee(t *testing.T) {
 	require.Equal(t, 3, len(discardedL2Txs))
 	require.Equal(t, 0, len(accAuths))
 }
+
+func TestL1UserFutureTxs(t *testing.T) {
+	set := `
+		Type: Blockchain
+
+		CreateAccountDeposit(0) Coord: 0
+		CreateAccountDeposit(0) A: 100
+
+		> batchL1 // freeze L1User{2}
+		CreateAccountDeposit(0) B: 18
+		> batchL1 // forge L1User{2}, freeze L1User{1}
+		> batchL1 // forge L1User{1}
+		> block
+	`
+
+	chainID := uint16(0)
+	tc := til.NewContext(chainID, common.RollupConstMaxL1UserTx)
+	blocks, err := tc.GenerateBlocks(set)
+	assert.NoError(t, err)
+
+	hermezContractAddr := ethCommon.HexToAddress("0xc344E203a046Da13b0B4467EB7B3629D0C99F6E6")
+	txsel, _ := initTest(t, chainID, hermezContractAddr, tc.Users["Coord"])
+
+	// restart nonces of TilContext, as will be set by generating directly
+	// the PoolL2Txs for each specific batch with tc.GeneratePoolL2Txs
+	tc.RestartNonces()
+
+	tpc := txprocessor.Config{
+		NLevels:  16,
+		MaxFeeTx: 10,
+		MaxTx:    10,
+		MaxL1Tx:  10,
+		ChainID:  chainID,
+	}
+	// batch1 to freeze L1UserTxs
+	l1UserTxs := []common.L1Tx{}
+	l1UserFutureTxs := []common.L1Tx{}
+	_, _, _, _, _, _, err = txsel.GetL1L2TxSelection(tpc, l1UserTxs, l1UserFutureTxs)
+	require.NoError(t, err)
+
+	batchPoolL2 := `
+	Type: PoolL2
+	PoolTransferToEthAddr(0) A-B: 10 (126)
+	`
+	poolL2Txs, err := tc.GeneratePoolL2Txs(batchPoolL2)
+	require.NoError(t, err)
+	require.Equal(t, 1, len(poolL2Txs))
+
+	// add AccountCreationAuth for B
+	_ = addAccCreationAuth(t, tc, txsel, chainID, hermezContractAddr, "B")
+	// add the PoolL2Txs to the l2DB
+	addL2Txs(t, txsel, poolL2Txs)
+	// batch 2 to crate some accounts with positive balance, and do 1 L2Tx transfer from account A
+	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[1].Batch.ForgeL1TxsNum])
+	l1UserFutureTxs =
+		til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[2].Batch.ForgeL1TxsNum])
+	require.Equal(t, 2, len(l1UserTxs))
+	require.Equal(t, 1, len(l1UserFutureTxs))
+	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err :=
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, l1UserFutureTxs)
+	require.NoError(t, err)
+	assert.Equal(t, 2, len(oL1UserTxs))
+	require.Equal(t, 0, len(oL1CoordTxs))
+	// no L2Tx selected due the L1UserFutureTx, the L2Tx will be processed
+	// at the next batch once the L1UserTx of CreateAccount B is processed,
+	// despite that there is an AccountCreationAuth for Account B.
+	assert.Equal(t, 0, len(oL2Txs))
+	assert.Equal(t, 1, len(discardedL2Txs))
+	assert.Equal(t, "Tx not selected (in processTxToEthAddrBJJ) due to L2Tx"+
+		" discarded at the current batch, as the receiver account does"+
+		" not exist yet, and there is a L1UserTx that will create that"+
+		" account in a future batch.",
+		discardedL2Txs[0].Info)
+
+	err = txsel.l2db.StartForging(common.TxIDsFromPoolL2Txs(oL2Txs),
+		txsel.localAccountsDB.CurrentBatch())
+	require.NoError(t, err)
+
+	l1UserTxs = til.L1TxsToCommonL1Txs(tc.Queues[*blocks[0].Rollup.Batches[2].Batch.ForgeL1TxsNum])
+	l1UserFutureTxs = []common.L1Tx{}
+	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
+		txsel.GetL1L2TxSelection(tpc, l1UserTxs, l1UserFutureTxs)
+	require.NoError(t, err)
+	assert.Equal(t, 1, len(oL1UserTxs))
+	require.Equal(t, 0, len(oL1CoordTxs))
+	// L2Tx selected as now the L1UserTx of CreateAccount B is processed
+	assert.Equal(t, 1, len(oL2Txs))
+	assert.Equal(t, 0, len(discardedL2Txs))
+	err = txsel.l2db.StartForging(common.TxIDsFromPoolL2Txs(oL2Txs),
+		txsel.localAccountsDB.CurrentBatch())
+	require.NoError(t, err)
+
+	// generate a new L2Tx A-B and check that is processed
+	poolL2Txs, err = tc.GeneratePoolL2Txs(batchPoolL2)
+	require.NoError(t, err)
+	require.Equal(t, 1, len(poolL2Txs))
+	// add the PoolL2Txs to the l2DB
+	addL2Txs(t, txsel, poolL2Txs)
+	_, _, oL1UserTxs, oL1CoordTxs, oL2Txs, discardedL2Txs, err =
+		txsel.GetL1L2TxSelection(tpc, nil, nil)
+	require.NoError(t, err)
+	assert.Equal(t, 0, len(oL1UserTxs))
+	require.Equal(t, 0, len(oL1CoordTxs))
+	assert.Equal(t, 1, len(oL2Txs))
+	assert.Equal(t, 0, len(discardedL2Txs))
+	err = txsel.l2db.StartForging(common.TxIDsFromPoolL2Txs(oL2Txs),
+		txsel.localAccountsDB.CurrentBatch())
+	require.NoError(t, err)
+}