From ac9551040289fe9acb11d3a1560fb7f9b307e75e Mon Sep 17 00:00:00 2001
From: Evgeniy Stratonikov <evgeniy@nspcc.ru>
Date: Wed, 10 Mar 2021 12:29:56 +0300
Subject: [PATCH] core: do not return block if only header is present

---
 pkg/core/blockchain.go      |  3 +++
 pkg/core/blockchain_test.go | 32 ++++++++++++++++++++++++++++++--
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index c8a6bc3b4..5af463146 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -1122,6 +1122,9 @@ func (bc *Blockchain) GetBlock(hash util.Uint256) (*block.Block, error) {
 	if err != nil {
 		return nil, err
 	}
+	if !block.MerkleRoot.Equals(util.Uint256{}) && len(block.Transactions) == 0 {
+		return nil, errors.New("only header is found")
+	}
 	for _, tx := range block.Transactions {
 		stx, _, err := bc.dao.GetTransaction(tx.Hash())
 		if err != nil {
diff --git a/pkg/core/blockchain_test.go b/pkg/core/blockchain_test.go
index 635f23510..05e2a27a3 100644
--- a/pkg/core/blockchain_test.go
+++ b/pkg/core/blockchain_test.go
@@ -230,6 +230,33 @@ func TestGetBlock(t *testing.T) {
 		}
 		assert.NoError(t, bc.persist())
 	}
+
+	t.Run("store only header", func(t *testing.T) {
+		t.Run("non-empty block", func(t *testing.T) {
+			tx, err := testchain.NewTransferFromOwner(bc, bc.contracts.NEO.Hash,
+				random.Uint160(), 1, 1, 1000)
+			b := bc.newBlock(tx)
+			require.NoError(t, bc.AddHeaders(&b.Header))
+
+			_, err = bc.GetBlock(b.Hash())
+			require.Error(t, err)
+
+			_, err = bc.GetHeader(b.Hash())
+			require.NoError(t, err)
+
+			require.NoError(t, bc.AddBlock(b))
+
+			_, err = bc.GetBlock(b.Hash())
+			require.NoError(t, err)
+		})
+		t.Run("empty block", func(t *testing.T) {
+			b := bc.newBlock()
+			require.NoError(t, bc.AddHeaders(&b.Header))
+
+			_, err = bc.GetBlock(b.Hash())
+			require.NoError(t, err)
+		})
+	})
 }
 
 func (bc *Blockchain) newTestTx(h util.Uint160, script []byte) *transaction.Transaction {
@@ -1558,9 +1585,10 @@ func TestRemoveUntraceable(t *testing.T) {
 	require.Error(t, err)
 	_, err = bc.GetAppExecResults(tx1.Hash(), trigger.Application)
 	require.Error(t, err)
-	b, err := bc.GetBlock(b1.Hash())
+	_, err = bc.GetBlock(b1.Hash())
+	require.Error(t, err)
+	_, err = bc.GetHeader(b1.Hash())
 	require.NoError(t, err)
-	require.Len(t, b.Transactions, 0)
 }
 
 func TestInvalidNotification(t *testing.T) {