lntypes: add ZeroHash

lntypes/hash.go

@@ -8,6 +8,9 @@ import (
 // HashSize of array used to store hashes.
 const HashSize = 32
 
+// ZeroHash is a predefined hash containing all zeroes.
+var ZeroHash Hash
+
 // Hash is used in several of the lightning messages and common structures. It
 // typically represents a payment hash.
 type Hash [HashSize]byte

rpcserver.go

@@ -67,8 +67,6 @@ const (
 )
 
 var (
-	zeroHash [32]byte
-
 	// MaxPaymentMSat is the maximum allowed payment currently permitted as
 	// defined in BOLT-002. This value depends on which chain is active.
 	// It is set to the value under the Bitcoin chain as default.
@@ -3018,7 +3016,9 @@ func extractPaymentIntent(rpcPayReq *rpcPaymentRequest) (rpcPaymentIntent, error
 	// If we're in debug HTLC mode, then all outgoing HTLCs will pay to the
 	// same debug rHash. Otherwise, we pay to the rHash specified within
 	// the RPC request.
-	case cfg.DebugHTLC && bytes.Equal(payIntent.rHash[:], zeroHash[:]):
+	case cfg.DebugHTLC &&
+		bytes.Equal(payIntent.rHash[:], lntypes.ZeroHash[:]):
+
 		copy(payIntent.rHash[:], invoices.DebugHash[:])
 
 	default: