From 73944e3299253e3dd1f7ec309412bd2074b8825c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miroslav=20Kov=C3=A1=C5=99?= <miroslavkovar@protonmail.com>
Date: Fri, 8 May 2026 00:32:49 +0200
Subject: [PATCH] core: record SetParentBeaconRoot beacon-root accesses in BAL
 (#34897)
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`SetParentBeaconRoot`, which is used by hivechain block customization
(`modifyBlock` passed to `GenerateChain` as `gen`), runs
`ProcessBeaconBlockRoot`, but those accesses are not being recorded in
BALs. Later, `GenerateChain` processes beacon root again with BAL
tracking, so BAL could miss earlier mutations.

This patch keeps current flow but records reads/writes from
`SetParentBeaconRoot` into the BAL when enabled. That fixes accounting
mismatch without changing execution order.

I tried to find a better solution which would avoid double beacon root
processing but kept running into PMT root mismatches. This is the
minimal working solution, and a temporary workaround to enable correct
Amsterdam block generation anyway. Long-term we should move to a single
canonical beacon-root processing path (or explicit idempotent handling)
so execution and BAL accounting happen exactly once.

Used by https://github.com/ethereum/hive/pull/1468 to enable Amsterdam
block generation in hivechain.

Signed-off-by: Miroslav Kovář <miroslavkovar@protonmail.com>
---
 core/chain_makers.go      | 11 ++++++++++-
 core/chain_makers_test.go | 27 ++++++++++++---------------
 2 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/core/chain_makers.go b/core/chain_makers.go
index 17bdd8ffa8..c2ca5064c6 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -80,6 +80,11 @@ func (b *BlockGen) SetNonce(nonce types.BlockNonce) {
 	b.header.Nonce = nonce
 }
 
+// SetSlotNumber sets the slot number field of the generated block.
+func (b *BlockGen) SetSlotNumber(slot uint64) {
+	b.header.SlotNumber = &slot
+}
+
 // SetDifficulty sets the difficulty field of the generated block. This method is
 // useful for Clique tests where the difficulty does not depend on time. For the
 // ethash tests, please use OffsetTime, which implicitly recalculates the diff.
@@ -102,7 +107,11 @@ func (b *BlockGen) Difficulty() *big.Int {
 func (b *BlockGen) SetParentBeaconRoot(root common.Hash) {
 	b.header.ParentBeaconRoot = &root
 	blockContext := NewEVMBlockContext(b.header, b.cm, &b.header.Coinbase)
-	ProcessBeaconBlockRoot(root, vm.NewEVM(blockContext, b.statedb, b.cm.config, vm.Config{}))
+	reads, writes := ProcessBeaconBlockRoot(root, vm.NewEVM(blockContext, b.statedb, b.cm.config, vm.Config{}))
+	if b.accessList != nil {
+		b.accessList.AddBlockInitMutations(writes)
+		b.accessList.AddAccesses(reads)
+	}
 }
 
 // addTx adds a transaction to the generated block. If no coinbase has
diff --git a/core/chain_makers_test.go b/core/chain_makers_test.go
index 5bb05653b8..657824c4d7 100644
--- a/core/chain_makers_test.go
+++ b/core/chain_makers_test.go
@@ -236,7 +236,7 @@ func TestGenerateBALChain(t *testing.T) {
 		// TODO: I think we can remove SetBeaconRoot entirely
 		// and provide a different mechanism to set it?
 
-		// gen.SetParentBeaconRoot(common.Hash{byte(i + 1)})
+		gen.SetParentBeaconRoot(common.Hash{byte(i + 1)})
 
 		if gspec.Config.IsAmsterdam(gen.header.Number, gen.header.Time) {
 			// TODO: parameterize the slot num
@@ -333,20 +333,17 @@ func TestGenerateBALChain(t *testing.T) {
 			withdrawalIndex += 1
 		}
 
-		// TODO: can we reinstate the following?
-		/*
-				// Verify parent beacon root.
-				want := common.Hash{byte(blocknum)}
-				if got := block.BeaconRoot(); *got != want {
-					t.Fatalf("block %d, wrong parent beacon root: got %s, want %s", i, got, want)
-				}
-			state, _ := blockchain.State()
-			idx := block.Time()%8191 + 8191
-			got := state.GetState(params.BeaconRootsAddress, common.BigToHash(new(big.Int).SetUint64(idx)))
-			if got != want {
-				t.Fatalf("block %d, wrong parent beacon root in state: got %s, want %s", i, got, want)
-			}
-		*/
+		// Verify parent beacon root.
+		want := common.Hash{byte(blocknum)}
+		if got := block.BeaconRoot(); *got != want {
+			t.Fatalf("block %d, wrong parent beacon root: got %s, want %s", i, got, want)
+		}
+		state, _ := blockchain.State()
+		idx := block.Time()%8191 + 8191
+		got := state.GetState(params.BeaconRootsAddress, common.BigToHash(new(big.Int).SetUint64(idx)))
+		if got != want {
+			t.Fatalf("block %d, wrong parent beacon root in state: got %s, want %s", i, got, want)
+		}
 	}
 }