work around rlp encoding/decoding issue for StakeMsg field type casting

staking/types/transaction.go

@@ -34,7 +34,12 @@ func (d *txdata) CopyFrom(d2 *txdata) {
 	d.Price = new(big.Int).Set(d2.Price)
 	d.GasLimit = d2.GasLimit
 	// TODO: add code to protect crashing
-	d.StakeMsg = d2.StakeMsg.(StakeMsg).Copy()
+	// This is workaround, direct RLP encoding/decoding not work
+	payload, _ := rlp.EncodeToBytes(d2.StakeMsg)
+	restored, _ := RLPDecodeStakeMsg(
+		payload, d2.Directive,
+	)
+	d.StakeMsg = restored.(StakeMsg).Copy()
 	d.V = new(big.Int).Set(d2.V)
 	d.R = new(big.Int).Set(d2.R)
 	d.S = new(big.Int).Set(d2.S)