use VMState as marker

pkg/core/state/notification_event.go

@@ -78,6 +78,10 @@ func (aer *AppExecResult) EncodeBinary(w *io.BinWriter) {
 func (aer *AppExecResult) EncodeBinaryWithContext(w *io.BinWriter, sc *stackitem.SerializationContext) {
 	w.WriteBytes(aer.Container[:])
 	w.WriteB(byte(aer.Trigger))
+	invocLen := len(aer.Invocations)
+	if invocLen > 0 {
+		aer.VMState |= 0x80
+	}
 	w.WriteB(byte(aer.VMState))
 	w.WriteU64LE(uint64(aer.GasConsumed))
 	// Stack items are expected to be marshaled one by one.
@@ -95,7 +99,7 @@ func (aer *AppExecResult) EncodeBinaryWithContext(w *io.BinWriter, sc *stackitem
 		aer.Events[i].EncodeBinaryWithContext(w, sc)
 	}
 	w.WriteVarBytes([]byte(aer.FaultException))
-	if invocLen := len(aer.Invocations); invocLen > 0 {
+	if invocLen > 0 {
 		w.WriteVarUint(uint64(invocLen))
 		for i := range aer.Invocations {
 			aer.Invocations[i].EncodeBinaryWithContext(w, sc)
@@ -126,7 +130,7 @@ func (aer *AppExecResult) DecodeBinary(r *io.BinReader) {
 	aer.Stack = arr
 	r.ReadArray(&aer.Events)
 	aer.FaultException = r.ReadString()
-	if r.Len() > 0 {
+	if aer.VMState&0x80 != 0 {
 		r.ReadArray(&aer.Invocations)
 	}
 }