From 71cfd14b9285359db55d3f793f9bf1bb58cba9c1 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Thu, 12 Sep 2019 11:24:10 +0300
Subject: [PATCH] vm: create an array of `false` items in NEWARRAY/NEWSTRUCT

---
 pkg/vm/vm.go      | 12 ++++++++++--
 pkg/vm/vm_test.go |  4 ++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/pkg/vm/vm.go b/pkg/vm/vm.go
index 6bb1efe39..b9c667c69 100644
--- a/pkg/vm/vm.go
+++ b/pkg/vm/vm.go
@@ -611,7 +611,7 @@ func (v *VM) execute(ctx *Context, op Instruction) {
 		switch t := item.value.(type) {
 		case *BigIntegerItem:
 			n := t.value.Int64()
-			items := make([]StackItem, n)
+			items := makeArrayOfFalses(int(n))
 			v.estack.PushVal(&ArrayItem{items})
 		case *StructItem:
 			v.estack.PushVal(&ArrayItem{t.value})
@@ -626,7 +626,7 @@ func (v *VM) execute(ctx *Context, op Instruction) {
 		switch t := item.value.(type) {
 		case *BigIntegerItem:
 			n := t.value.Int64()
-			items := make([]StackItem, n)
+			items := makeArrayOfFalses(int(n))
 			v.estack.PushVal(&StructItem{items})
 		case *ArrayItem:
 			v.estack.PushVal(&StructItem{t.value})
@@ -853,6 +853,14 @@ func (v *VM) execute(ctx *Context, op Instruction) {
 	}
 }
 
+func makeArrayOfFalses(n int) []StackItem {
+	items := make([]StackItem, n)
+	for i := range items {
+		items[i] = &BoolItem{false}
+	}
+	return items
+}
+
 func init() {
 	log.SetPrefix("NEO-GO-VM > ")
 	log.SetFlags(0)
diff --git a/pkg/vm/vm_test.go b/pkg/vm/vm_test.go
index c45c2f0cb..d813ebc89 100644
--- a/pkg/vm/vm_test.go
+++ b/pkg/vm/vm_test.go
@@ -397,7 +397,7 @@ func TestNEWARRAYInteger(t *testing.T) {
 	vm.Run()
 	assert.Equal(t, false, vm.state.HasFlag(faultState))
 	assert.Equal(t, 1, vm.estack.Len())
-	assert.Equal(t, &ArrayItem{make([]StackItem, 1)}, vm.estack.Pop().value)
+	assert.Equal(t, &ArrayItem{[]StackItem{makeStackItem(false)}}, vm.estack.Pop().value)
 }
 
 func TestNEWARRAYStruct(t *testing.T) {
@@ -437,7 +437,7 @@ func TestNEWSTRUCTInteger(t *testing.T) {
 	vm.Run()
 	assert.Equal(t, false, vm.state.HasFlag(faultState))
 	assert.Equal(t, 1, vm.estack.Len())
-	assert.Equal(t, &StructItem{make([]StackItem, 1)}, vm.estack.Pop().value)
+	assert.Equal(t, &StructItem{[]StackItem{makeStackItem(false)}}, vm.estack.Pop().value)
 }
 
 func TestNEWSTRUCTArray(t *testing.T) {