Fix panic when fetching block with empty block id from ChainManager (#…

…133)

.changeset/fix_panic_when_fetching_block_with_empty_block_id_from_chainmanager.md

@@ -0,0 +1,5 @@
+---
+default: patch
+---
+
+# Fix panic when fetching block with empty block id from ChainManager

chain/db.go

@@ -295,12 +295,13 @@ func (db *DBStore) putState(cs consensus.State) {
 
 func (db *DBStore) getBlock(id types.BlockID) (bh types.BlockHeader, b *types.Block, bs *consensus.V1BlockSupplement, _ bool) {
 	var sb supplementedBlock
-	ok := db.bucket(bBlocks).get(id[:], &sb)
-	if sb.Header == nil {
+	if ok := db.bucket(bBlocks).get(id[:], &sb); !ok {
+		return types.BlockHeader{}, nil, nil, false
+	} else if sb.Header == nil {
 		sb.Header = new(types.BlockHeader)
 		*sb.Header = sb.Block.Header()
 	}
-	return *sb.Header, sb.Block, sb.Supplement, ok
+	return *sb.Header, sb.Block, sb.Supplement, true
 }
 
 func (db *DBStore) putBlock(bh types.BlockHeader, b *types.Block, bs *consensus.V1BlockSupplement) {

chain/db_test.go

@@ -0,0 +1,19 @@
+package chain_test
+
+import (
+	"testing"
+
+	"go.sia.tech/core/types"
+	"go.sia.tech/coreutils/chain"
+	"go.sia.tech/coreutils/testutil"
+)
+
+func TestGetEmptyBlockID(t *testing.T) {
+	n, genesisBlock := testutil.V2Network()
+	store, tipState, err := chain.NewDBStore(chain.NewMemDB(), n, genesisBlock)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cm := chain.NewManager(store, tipState)
+	_, _ = cm.Block(types.BlockID{})
+}