From 58707c2b1ec2bf730933f36524cc142f1795261f Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 31 Aug 2022 10:53:49 +0300
Subject: [PATCH] context: handle the case when we have more sigs than needed

We can technically have more signatures in the file than we need and it's OK,
this case should be handled.
---
 pkg/smartcontract/context/context.go      | 11 ++++--
 pkg/smartcontract/context/context_test.go | 46 +++++++++++++++--------
 2 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/pkg/smartcontract/context/context.go b/pkg/smartcontract/context/context.go
index fd768604d..cd4d09d0e 100644
--- a/pkg/smartcontract/context/context.go
+++ b/pkg/smartcontract/context/context.go
@@ -96,14 +96,19 @@ func (c *ParameterContext) AddSignature(h util.Uint160, ctr *wallet.Contract, pu
 			return errors.New("public key is not present in script")
 		}
 		item.AddSignature(pub, sig)
-		if len(item.Signatures) == len(ctr.Parameters) {
+		if len(item.Signatures) >= len(ctr.Parameters) {
 			indexMap := map[string]int{}
 			for i := range pubs {
 				indexMap[hex.EncodeToString(pubs[i])] = i
 			}
-			sigs := make([]sigWithIndex, 0, len(item.Signatures))
+			sigs := make([]sigWithIndex, len(item.Parameters))
+			var i int
 			for pub, sig := range item.Signatures {
-				sigs = append(sigs, sigWithIndex{index: indexMap[pub], sig: sig})
+				sigs[i] = sigWithIndex{index: indexMap[pub], sig: sig}
+				i++
+				if i == len(sigs) {
+					break
+				}
 			}
 			sort.Slice(sigs, func(i, j int) bool {
 				return sigs[i].index < sigs[j].index
diff --git a/pkg/smartcontract/context/context_test.go b/pkg/smartcontract/context/context_test.go
index 0b73c5718..c873b63e8 100644
--- a/pkg/smartcontract/context/context_test.go
+++ b/pkg/smartcontract/context/context_test.go
@@ -96,24 +96,38 @@ func TestParameterContext_AddSignatureMultisig(t *testing.T) {
 	sig := priv.SignHashable(uint32(c.Network), tx)
 	require.Error(t, c.AddSignature(ctr.ScriptHash(), ctr, priv.PublicKey(), sig))
 
-	indices := []int{2, 3, 0} // random order
-	for _, i := range indices {
-		sig := privs[i].SignHashable(uint32(c.Network), tx)
-		require.NoError(t, c.AddSignature(ctr.ScriptHash(), ctr, pubs[i], sig))
-		require.Error(t, c.AddSignature(ctr.ScriptHash(), ctr, pubs[i], sig))
+	indices := []int{2, 3, 0, 1} // random order
+	testSigWit := func(t *testing.T, num int) {
+		for _, i := range indices[:num] {
+			sig := privs[i].SignHashable(uint32(c.Network), tx)
+			require.NoError(t, c.AddSignature(ctr.ScriptHash(), ctr, pubs[i], sig))
+			require.Error(t, c.AddSignature(ctr.ScriptHash(), ctr, pubs[i], sig))
 
-		item := c.Items[ctr.ScriptHash()]
-		require.NotNil(t, item)
-		require.Equal(t, sig, item.GetSignature(pubs[i]))
+			item := c.Items[ctr.ScriptHash()]
+			require.NotNil(t, item)
+			require.Equal(t, sig, item.GetSignature(pubs[i]))
+		}
+
+		t.Run("GetWitness", func(t *testing.T) {
+			w, err := c.GetWitness(ctr.ScriptHash())
+			require.NoError(t, err)
+			v := newTestVM(w, tx)
+			require.NoError(t, v.Run())
+			require.Equal(t, 1, v.Estack().Len())
+			require.Equal(t, true, v.Estack().Pop().Value())
+		})
 	}
-
-	t.Run("GetWitness", func(t *testing.T) {
-		w, err := c.GetWitness(ctr.ScriptHash())
-		require.NoError(t, err)
-		v := newTestVM(w, tx)
-		require.NoError(t, v.Run())
-		require.Equal(t, 1, v.Estack().Len())
-		require.Equal(t, true, v.Estack().Pop().Value())
+	t.Run("exact number of sigs", func(t *testing.T) {
+		testSigWit(t, 3)
+	})
+	t.Run("larger number of sigs", func(t *testing.T) {
+		// Clean up.
+		var itm = c.Items[ctr.ScriptHash()]
+		for i := range itm.Parameters {
+			itm.Parameters[i].Value = nil
+		}
+		itm.Signatures = make(map[string][]byte)
+		testSigWit(t, 4)
 	})
 }