From e423d5cf9ef22aa1f35c91ea126b71443a27972a Mon Sep 17 00:00:00 2001
From: Guillaume Ballet <3272758+gballet@users.noreply.github.com>
Date: Fri, 26 Jan 2024 15:45:19 +0100
Subject: [PATCH] add a test to verify the transition from legacy to contract

---
 core/vm/instructions_test.go | 74 ++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/core/vm/instructions_test.go b/core/vm/instructions_test.go
index 807073336d..5f481a7fbe 100644
--- a/core/vm/instructions_test.go
+++ b/core/vm/instructions_test.go
@@ -18,6 +18,7 @@ package vm
 
 import (
 	"bytes"
+	"encoding/binary"
 	"encoding/json"
 	"fmt"
 	"math/big"
@@ -791,6 +792,79 @@ func TestBlobHash(t *testing.T) {
 	}
 }
 
+func TestBlockHashEip2935(t *testing.T) {
+	type testcase struct {
+		name   string
+		idx    uint64
+		expect common.Hash
+		hashes []common.Hash
+	}
+	var (
+		statedb, _ = state.New(types.EmptyRootHash, state.NewDatabase(rawdb.NewMemoryDatabase()), nil)
+		expect     = common.HexToHash("0x1234")
+		getHash    = func(uint64) common.Hash {
+			return expect
+		}
+		newUint64    = func(val uint64) *uint64 { return &val }
+		blockContext = BlockContext{BlockNumber: big.NewInt(100), GetHash: getHash, Time: 0}
+		chainConfig  = &params.ChainConfig{
+			ChainID:                       big.NewInt(1337),
+			HomesteadBlock:                big.NewInt(0),
+			EIP150Block:                   big.NewInt(0),
+			EIP155Block:                   big.NewInt(0),
+			EIP158Block:                   big.NewInt(0),
+			ByzantiumBlock:                big.NewInt(0),
+			ConstantinopleBlock:           big.NewInt(0),
+			PetersburgBlock:               big.NewInt(0),
+			IstanbulBlock:                 big.NewInt(0),
+			MuirGlacierBlock:              big.NewInt(0),
+			BerlinBlock:                   big.NewInt(0),
+			LondonBlock:                   big.NewInt(0),
+			ArrowGlacierBlock:             big.NewInt(0),
+			GrayGlacierBlock:              big.NewInt(0),
+			ShanghaiTime:                  newUint64(0),
+			PragueTime:                    newUint64(0),
+			TerminalTotalDifficulty:       big.NewInt(0),
+			TerminalTotalDifficultyPassed: true,
+		}
+		env             = NewEVM(blockContext, TxContext{}, statedb, chainConfig, Config{})
+		stack           = newstack()
+		pc              = uint64(0)
+		evmInterpreter  = env.interpreter
+		callBlockHash10 = func(t *testing.T, name string) {
+			stack.push(uint256.NewInt(10))
+			opBlockhash(&pc, evmInterpreter, &ScopeContext{nil, stack, nil})
+			if len(stack.data) != 1 {
+				t.Errorf("Expected one item on stack got %d: ", len(stack.data))
+			}
+			actual := stack.pop()
+			expected, overflow := uint256.FromBig(new(big.Int).SetBytes(expect.Bytes()))
+			if overflow {
+				t.Errorf("invalid overflow")
+			}
+			if actual.Cmp(expected) != 0 {
+				t.Errorf("%s: expected  %x, got %x", name, expected, actual)
+			}
+		}
+	)
+
+	// insert 500 block hashes, starting from genesis.
+	for i := uint64(0); i < 500; i++ {
+		var blockNumber common.Hash
+		binary.BigEndian.PutUint64(blockNumber[24:], i)
+		statedb.SetState(params.HistoryStorageAddress, blockNumber, expect)
+	}
+
+	// simulate a call to BLOCKHASH at block 100, i.e. less than 256
+	// blocks after a genesis with eip 2935 activated.
+	callBlockHash10(t, "legacy")
+
+	// now do the same thing much later, after all blocks have
+	// been inserted.
+	env.Context.BlockNumber.SetInt64(500)
+	callBlockHash10(t, "contract")
+}
+
 func TestOpMCopy(t *testing.T) {
 	// Test cases from https://eips.ethereum.org/EIPS/eip-5656#test-cases
 	for i, tc := range []struct {