From e332431cb28c6d374504fc5343fafaf3157a6aee Mon Sep 17 00:00:00 2001 From: Felix Lange Date: Tue, 4 Feb 2025 17:16:26 +0100 Subject: [PATCH] core: assign default difficulty to zero for chain without ethash (#31067) I hit this case while trying something with the simulated backend. The EVM only enables instruction set forks after the merge when 'Random' is set. In the simulated backend, the random value will be set via the engine API for all blocks after genesis. But for the genesis block itself, the random value will not be assigned in the vm.BlockContext because the genesis has a non-zero difficulty. For my case, this meant that estimateGas did not work for the first transaction sent on the simulated chain, since the contract contained a PUSH0 instruction. This could also be fixed by explicitly configuring a zero difficulty in the simulated backend. However, I think that zero difficulty is a better default these days. --------- Co-authored-by: lightclient --- core/genesis.go | 8 ++++++-- core/genesis_test.go | 4 ++-- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/core/genesis.go b/core/genesis.go index d1ee1b6e92..8f71f9ef1e 100644 --- a/core/genesis.go +++ b/core/genesis.go @@ -464,8 +464,12 @@ func (g *Genesis) toBlockWithRoot(root common.Hash) *types.Block { if g.GasLimit == 0 { head.GasLimit = params.GenesisGasLimit } - if g.Difficulty == nil && g.Mixhash == (common.Hash{}) { - head.Difficulty = params.GenesisDifficulty + if g.Difficulty == nil { + if g.Config != nil && g.Config.Ethash == nil { + head.Difficulty = big.NewInt(0) + } else if g.Mixhash == (common.Hash{}) { + head.Difficulty = params.GenesisDifficulty + } } if g.Config != nil && g.Config.IsLondon(common.Big0) { if g.BaseFee != nil { diff --git a/core/genesis_test.go b/core/genesis_test.go index 3e120a9307..ad75afcd9e 100644 --- a/core/genesis_test.go +++ b/core/genesis_test.go @@ -44,14 +44,14 @@ func testSetupGenesis(t *testing.T, scheme string) { var ( customghash = common.HexToHash("0x89c99d90b79719238d2645c7642f2c9295246e80775b38cfd162b696817fbd50") customg = Genesis{ - Config: ¶ms.ChainConfig{HomesteadBlock: big.NewInt(3)}, + Config: ¶ms.ChainConfig{HomesteadBlock: big.NewInt(3), Ethash: ¶ms.EthashConfig{}}, Alloc: types.GenesisAlloc{ {1}: {Balance: big.NewInt(1), Storage: map[common.Hash]common.Hash{{1}: {1}}}, }, } oldcustomg = customg ) - oldcustomg.Config = ¶ms.ChainConfig{HomesteadBlock: big.NewInt(2)} + oldcustomg.Config = ¶ms.ChainConfig{HomesteadBlock: big.NewInt(2), Ethash: ¶ms.EthashConfig{}} tests := []struct { name string