From 5e657a5a856773a2120dc2149db995dcc7505b3e Mon Sep 17 00:00:00 2001
From: Guillaume Ballet <3272758+gballet@users.noreply.github.com>
Date: Wed, 26 Jan 2022 10:07:51 +0100
Subject: [PATCH] fix: build more than one block in stateless test (#66)

* reproduce the bug

* fix the nil AccessWitness when Resetting

* fix nonce management in blocks

* fix: make sure the snapshot is reused during the chain generation
---
 core/chain_makers.go         | 5 ++++-
 core/state/statedb.go        | 4 ++++
 core/state_processor_test.go | 8 ++++----
 core/vm/evm.go               | 3 +++
 4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/core/chain_makers.go b/core/chain_makers.go
index 6d691dbc3685..528627261119 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -24,6 +24,7 @@ import (
 	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/consensus/misc"
 	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/state/snapshot"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/ethdb"
@@ -357,8 +358,9 @@ func GenerateVerkleChain(config *params.ChainConfig, parent *types.Block, engine
 		}
 		return nil, nil
 	}
+	var snaps *snapshot.Tree
 	for i := 0; i < n; i++ {
-		statedb, err := state.New(parent.Root(), state.NewDatabaseWithConfig(db, &trie.Config{UseVerkle: true}), nil)
+		statedb, err := state.New(parent.Root(), state.NewDatabaseWithConfig(db, &trie.Config{UseVerkle: true}), snaps)
 		if err != nil {
 			panic(err)
 		}
@@ -366,6 +368,7 @@ func GenerateVerkleChain(config *params.ChainConfig, parent *types.Block, engine
 		blocks[i] = block
 		receipts[i] = receipt
 		parent = block
+		snaps = statedb.Snaps()
 	}
 	return blocks, receipts
 }
diff --git a/core/state/statedb.go b/core/state/statedb.go
index 0828ae95060a..3a63e7faceea 100644
--- a/core/state/statedb.go
+++ b/core/state/statedb.go
@@ -168,6 +168,10 @@ func New(root common.Hash, db Database, snaps *snapshot.Tree) (*StateDB, error)
 	return sdb, nil
 }
 
+func (s *StateDB) Snaps() *snapshot.Tree {
+	return s.snaps
+}
+
 func (s *StateDB) Witness() *types.AccessWitness {
 	return s.witness
 }
diff --git a/core/state_processor_test.go b/core/state_processor_test.go
index 93a41f2ecba9..82ec894c74f7 100644
--- a/core/state_processor_test.go
+++ b/core/state_processor_test.go
@@ -377,12 +377,12 @@ func TestProcessStateless(t *testing.T) {
 	genesis := gspec.MustCommit(db)
 	blockchain, _ := NewBlockChain(db, nil, gspec.Config, ethash.NewFaker(), vm.Config{}, nil, nil)
 	defer blockchain.Stop()
-	chain, _ := GenerateVerkleChain(gspec.Config, genesis, ethash.NewFaker(), db, 1, func(_ int, gen *BlockGen) {
-		tx, _ := types.SignTx(types.NewTransaction(0, common.Address{1, 2, 3}, big.NewInt(999), params.TxGas, big.NewInt(875000000), nil), signer, testKey)
+	chain, _ := GenerateVerkleChain(gspec.Config, genesis, ethash.NewFaker(), db, 2, func(i int, gen *BlockGen) {
+		tx, _ := types.SignTx(types.NewTransaction(uint64(i)*3, common.Address{1, 2, 3}, big.NewInt(999), params.TxGas, big.NewInt(875000000), nil), signer, testKey)
 		gen.AddTx(tx)
-		tx, _ = types.SignTx(types.NewTransaction(1, common.Address{}, big.NewInt(999), params.TxGas, big.NewInt(875000000), nil), signer, testKey)
+		tx, _ = types.SignTx(types.NewTransaction(uint64(i)*3+1, common.Address{}, big.NewInt(999), params.TxGas, big.NewInt(875000000), nil), signer, testKey)
 		gen.AddTx(tx)
-		tx, _ = types.SignTx(types.NewTransaction(2, common.Address{}, big.NewInt(0), params.TxGas, big.NewInt(875000000), nil), signer, testKey)
+		tx, _ = types.SignTx(types.NewTransaction(uint64(i)*3+2, common.Address{}, big.NewInt(0), params.TxGas, big.NewInt(875000000), nil), signer, testKey)
 		gen.AddTx(tx)
 
 	})
diff --git a/core/vm/evm.go b/core/vm/evm.go
index 178ff4b36a18..a976eca45871 100644
--- a/core/vm/evm.go
+++ b/core/vm/evm.go
@@ -148,6 +148,9 @@ func NewEVM(blockCtx BlockContext, txCtx TxContext, statedb StateDB, chainConfig
 // Reset resets the EVM with a new transaction context.Reset
 // This is not threadsafe and should only be done very cautiously.
 func (evm *EVM) Reset(txCtx TxContext, statedb StateDB) {
+	if txCtx.Accesses == nil && evm.chainConfig.IsCancun(evm.Context.BlockNumber) {
+		txCtx.Accesses = types.NewAccessWitness()
+	}
 	evm.TxContext = txCtx
 	evm.StateDB = statedb
 }