From fbd599a2cbe193c42c77010bb9738f525899b060 Mon Sep 17 00:00:00 2001
From: Conner Fromknecht <conner@lightning.engineering>
Date: Tue, 19 Nov 2019 20:40:29 -0800
Subject: [PATCH] multi: rename Payment.PaymentPreimage to Payment.Preimage

Preliminary step to exposing PaymentPreimage() as a method that can be
shared between legacy payments and mutli-path payments.
---
 channeldb/payments.go    |  8 ++++----
 routing/control_tower.go |  2 +-
 rpcserver.go             | 12 ++++++------
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/channeldb/payments.go b/channeldb/payments.go
index d576c65c..ddf80ed0 100644
--- a/channeldb/payments.go
+++ b/channeldb/payments.go
@@ -239,11 +239,11 @@ type Payment struct {
 	// NOTE: Can be nil if no attempt is yet made.
 	Attempt *PaymentAttemptInfo
 
-	// PaymentPreimage is the preimage of a successful payment. This serves
-	// as a proof of payment. It will only be non-nil for settled payments.
+	// Preimage is the preimage of a successful payment. This serves as a
+	// proof of payment. It will only be non-nil for settled payments.
 	//
 	// NOTE: Can be nil if payment is not settled.
-	PaymentPreimage *lntypes.Preimage
+	Preimage *lntypes.Preimage
 
 	// Failure is a failure reason code indicating the reason the payment
 	// failed. It is only non-nil for failed payments.
@@ -363,7 +363,7 @@ func fetchPayment(bucket *bbolt.Bucket) (*Payment, error) {
 	if b != nil {
 		var preimg lntypes.Preimage
 		copy(preimg[:], b[:])
-		p.PaymentPreimage = &preimg
+		p.Preimage = &preimg
 	}
 
 	// Get failure reason if available.
diff --git a/routing/control_tower.go b/routing/control_tower.go
index 0bf08476..9cd63a95 100644
--- a/routing/control_tower.go
+++ b/routing/control_tower.go
@@ -214,7 +214,7 @@ func (p *controlTower) SubscribePayment(paymentHash lntypes.Hash) (
 	// immediately.
 	case channeldb.StatusSucceeded:
 		event = *createSuccessResult(
-			&payment.Attempt.Route, *payment.PaymentPreimage,
+			&payment.Attempt.Route, *payment.Preimage,
 		)
 
 	// Payment already failed. It is not necessary to register as a
diff --git a/rpcserver.go b/rpcserver.go
index 828ce7cf..157a714a 100644
--- a/rpcserver.go
+++ b/rpcserver.go
@@ -4348,9 +4348,8 @@ func (r *rpcServer) ListPayments(ctx context.Context,
 			continue
 		}
 
-		// If a payment attempt has been made we can fetch the route.
-		// Otherwise we'll just populate the RPC response with an empty
-		// one.
+		// Fetch the payment's route, which will be empty if an attempt
+		// has not been made.
 		var route route.Route
 		if payment.Attempt != nil {
 			route = payment.Attempt.Route
@@ -4360,10 +4359,11 @@ func (r *rpcServer) ListPayments(ctx context.Context,
 			path[i] = hex.EncodeToString(hop.PubKeyBytes[:])
 		}
 
-		// If this payment is settled, the preimage will be available.
+		// Fetch the preimage if the payment was successful, otherwise a
+		// zero-value preimage will be used.
 		var preimage lntypes.Preimage
-		if payment.PaymentPreimage != nil {
-			preimage = *payment.PaymentPreimage
+		if payment.Preimage != nil {
+			preimage = *payment.Preimage
 		}
 
 		msatValue := int64(payment.Info.Value)