From 003daf37cfc94687a53726a3acfe07339a2ed275 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Thu, 25 Jun 2020 17:32:58 +0300
Subject: [PATCH] vm/cli: add parameter checks for load* commands

Prevent failing like this:

NEO-GO-VM > loadhex
panic: runtime error: index out of range

...
---
 pkg/vm/cli/cli.go | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/pkg/vm/cli/cli.go b/pkg/vm/cli/cli.go
index 6355491c6..29615c58b 100644
--- a/pkg/vm/cli/cli.go
+++ b/pkg/vm/cli/cli.go
@@ -243,6 +243,10 @@ func handleXStack(c *ishell.Context) {
 
 func handleLoadAVM(c *ishell.Context) {
 	v := getVMFromContext(c)
+	if len(c.Args) < 1 {
+		c.Err(errors.New("missing parameter <file>"))
+		return
+	}
 	if err := v.LoadFile(c.Args[0]); err != nil {
 		c.Err(err)
 	} else {
@@ -253,6 +257,10 @@ func handleLoadAVM(c *ishell.Context) {
 
 func handleLoadBase64(c *ishell.Context) {
 	v := getVMFromContext(c)
+	if len(c.Args) < 1 {
+		c.Err(errors.New("missing parameter <string>"))
+		return
+	}
 	b, err := base64.StdEncoding.DecodeString(c.Args[0])
 	if err != nil {
 		c.Err(err)
@@ -265,6 +273,10 @@ func handleLoadBase64(c *ishell.Context) {
 
 func handleLoadHex(c *ishell.Context) {
 	v := getVMFromContext(c)
+	if len(c.Args) < 1 {
+		c.Err(errors.New("missing parameter <string>"))
+		return
+	}
 	b, err := hex.DecodeString(c.Args[0])
 	if err != nil {
 		c.Err(err)
@@ -277,6 +289,10 @@ func handleLoadHex(c *ishell.Context) {
 
 func handleLoadGo(c *ishell.Context) {
 	v := getVMFromContext(c)
+	if len(c.Args) < 1 {
+		c.Err(errors.New("missing parameter <file>"))
+		return
+	}
 	fb, err := ioutil.ReadFile(c.Args[0])
 	if err != nil {
 		c.Err(err)