fixup! multi: Support custom size onion packets

Author: gijswijs

sphinx.go

@@ -224,24 +224,6 @@ func NewOnionPacket(paymentPath *PaymentPath, sessionKey *btcec.PrivateKey,
 		return nil, ErrPayloadSizeExceeded
 	}
 
-	// If the payload size is not equal to MaxRoutingPayloadSize, then we
-	// check if any of the hops have a legacy payload. If so, we return an
-	// error as legacy payloads are not supported for those payload sizes.
-	if payloadSize != MaxRoutingPayloadSize {
-		for i := 0; i < numHops; i++ {
-			hopPayload := (*paymentPath)[i].HopPayload
-			isLegacy := hopPayload.Type == PayloadLegacy
-
-			// For any onion size other than MaxRoutingPayloadSize,
-			// we only expect TLV payloads.
-			if isLegacy {
-				return nil, fmt.Errorf("hop %d has legacy "+
-					"payload, but this payload size "+
-					"requires TLV,", i)
-			}
-		}
-	}
-
 	// We'll force the caller to provide a packet filler, as otherwise we
 	// may default to an insecure filling method (which should only really
 	// be used to generate test vectors).