vm: do not fault on LEFT with big index

Fixes #378.
This commit is contained in:
Evgenii 2019-09-09 17:05:40 +03:00
parent a039ae6cdb
commit 0b58ed4a22
2 changed files with 7 additions and 2 deletions

View file

@ -315,6 +315,9 @@ func (v *VM) execute(ctx *Context, op Instruction) {
case LEFT:
l := int(v.estack.Pop().BigInt().Int64())
s := v.estack.Pop().Bytes()
if t := len(s); l > t {
l = t
}
v.estack.PushVal(s[:l])
case RIGHT:
l := int(v.estack.Pop().BigInt().Int64())

View file

@ -685,13 +685,15 @@ func TestLEFTGood(t *testing.T) {
assert.Equal(t, []byte("ab"), vm.estack.Peek(0).Bytes())
}
func TestLEFTBadLen(t *testing.T) {
func TestLEFTGoodLen(t *testing.T) {
prog := makeProgram(LEFT)
vm := load(prog)
vm.estack.PushVal([]byte("abcdef"))
vm.estack.PushVal(8)
vm.Run()
assert.Equal(t, true, vm.state.HasFlag(faultState))
assert.Equal(t, false, vm.state.HasFlag(faultState))
assert.Equal(t, 1, vm.estack.Len())
assert.Equal(t, []byte("abcdef"), vm.estack.Peek(0).Bytes())
}
func TestRIGHTBadNoArgs(t *testing.T) {