From 991e52db2aaf213d5867f3e89887e8f2b881b70c Mon Sep 17 00:00:00 2001
From: Aurora Gaffney <aurora@blinklabs.io>
Date: Sat, 29 Mar 2025 11:01:05 -0400
Subject: [PATCH] fix: expose Byron block number

Signed-off-by: Aurora Gaffney <aurora@blinklabs.io>
---
 cmd/gouroboros/chainsync.go | 10 ++++++----
 ledger/byron/byron.go       |  8 +++-----
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/cmd/gouroboros/chainsync.go b/cmd/gouroboros/chainsync.go
index 6e6b8236..f1184686 100644
--- a/cmd/gouroboros/chainsync.go
+++ b/cmd/gouroboros/chainsync.go
@@ -279,17 +279,19 @@ func chainSyncRollForwardHandler(
 	case ledger.BlockTypeByronEbb:
 		byronEbbBlock := block.(*ledger.ByronEpochBoundaryBlock)
 		fmt.Printf(
-			"era = Byron (EBB), epoch = %d, slot = %d, id = %s\n",
+			"era = Byron (EBB), epoch = %d, slot = %d, block_no = %d, id = %s\n",
 			byronEbbBlock.BlockHeader.ConsensusData.Epoch,
 			byronEbbBlock.SlotNumber(),
+			byronEbbBlock.BlockNumber(),
 			byronEbbBlock.Hash(),
 		)
 	case ledger.BlockTypeByronMain:
 		byronBlock := block.(*ledger.ByronMainBlock)
 		fmt.Printf(
-			"era = Byron, epoch = %d, slot = %d, id = %s\n",
+			"era = Byron, epoch = %d, slot = %d, block_no = %d, id = %s\n",
 			byronBlock.BlockHeader.ConsensusData.SlotId.Epoch,
 			byronBlock.SlotNumber(),
+			byronBlock.BlockNumber(),
 			byronBlock.Hash(),
 		)
 	default:
@@ -314,9 +316,9 @@ func blockFetchBlockHandler(
 ) error {
 	switch block := blockData.(type) {
 	case *ledger.ByronEpochBoundaryBlock:
-		fmt.Printf("era = Byron (EBB), epoch = %d, slot = %d, id = %s\n", block.BlockHeader.ConsensusData.Epoch, block.SlotNumber(), block.Hash())
+		fmt.Printf("era = Byron (EBB), epoch = %d, slot = %d, block_no = %d, id = %s\n", block.BlockHeader.ConsensusData.Epoch, block.SlotNumber(), block.BlockNumber(), block.Hash())
 	case *ledger.ByronMainBlock:
-		fmt.Printf("era = Byron, epoch = %d, slot = %d, id = %s\n", block.BlockHeader.ConsensusData.SlotId.Epoch, block.SlotNumber(), block.Hash())
+		fmt.Printf("era = Byron, epoch = %d, slot = %d, block_no = %d, id = %s\n", block.BlockHeader.ConsensusData.SlotId.Epoch, block.SlotNumber(), block.BlockNumber(), block.Hash())
 	case ledger.Block:
 		fmt.Printf("era = %s, slot = %d, block_no = %d, id = %s\n", block.Era().Name, block.SlotNumber(), block.BlockNumber(), block.Hash())
 	}
diff --git a/ledger/byron/byron.go b/ledger/byron/byron.go
index 84e5e956..9a13aec8 100644
--- a/ledger/byron/byron.go
+++ b/ledger/byron/byron.go
@@ -66,7 +66,7 @@ type ByronMainBlockHeader struct {
 		PubKey     []byte
 		Difficulty struct {
 			cbor.StructAsArray
-			Unknown uint64
+			Value uint64
 		}
 		BlockSig []interface{}
 	}
@@ -105,8 +105,7 @@ func (h *ByronMainBlockHeader) PrevHash() string {
 }
 
 func (h *ByronMainBlockHeader) BlockNumber() uint64 {
-	// Byron blocks don't store the block number in the block
-	return 0
+	return h.ConsensusData.Difficulty.Value
 }
 
 func (h *ByronMainBlockHeader) SlotNumber() uint64 {
@@ -538,8 +537,7 @@ func (h *ByronEpochBoundaryBlockHeader) PrevHash() string {
 }
 
 func (h *ByronEpochBoundaryBlockHeader) BlockNumber() uint64 {
-	// Byron blocks don't store the block number in the block
-	return 0
+	return h.ConsensusData.Difficulty.Value
 }
 
 func (h *ByronEpochBoundaryBlockHeader) SlotNumber() uint64 {