multi: update PaymentAddr to use fn.Option

Since it is allowed to not be set and so can lead to nil deref panics if
it is a pointer.

routing/router_test.go

@@ -1653,14 +1653,14 @@ func TestBuildRoute(t *testing.T) {
 	// Test that we can't build a route when no hops are given.
 	hops = []route.Vertex{}
 	_, err = ctx.router.BuildRoute(
-		noAmt, hops, nil, 40, nil, fn.None[[]byte](),
+		noAmt, hops, nil, 40, fn.None[[32]byte](), fn.None[[]byte](),
 	)
 	require.Error(t, err)
 
 	// Create hop list for an unknown destination.
 	hops := []route.Vertex{ctx.aliases["b"], ctx.aliases["y"]}
 	_, err = ctx.router.BuildRoute(
-		noAmt, hops, nil, 40, &payAddr, fn.None[[]byte](),
+		noAmt, hops, nil, 40, fn.Some(payAddr), fn.None[[]byte](),
 	)
 	noChanErr := ErrNoChannel{}
 	require.ErrorAs(t, err, &noChanErr)
@@ -1672,7 +1672,8 @@ func TestBuildRoute(t *testing.T) {
 
 	// Build the route for the given amount.
 	rt, err := ctx.router.BuildRoute(
-		fn.Some(amt), hops, nil, 40, &payAddr, fn.None[[]byte](),
+		fn.Some(amt), hops, nil, 40, fn.Some(payAddr),
+		fn.None[[]byte](),
 	)
 	require.NoError(t, err)
 
@@ -1684,7 +1685,7 @@ func TestBuildRoute(t *testing.T) {
 
 	// Build the route for the minimum amount.
 	rt, err = ctx.router.BuildRoute(
-		noAmt, hops, nil, 40, &payAddr, fn.None[[]byte](),
+		noAmt, hops, nil, 40, fn.Some(payAddr), fn.None[[]byte](),
 	)
 	require.NoError(t, err)
 
@@ -1702,7 +1703,7 @@ func TestBuildRoute(t *testing.T) {
 	// There is no amount that can pass through both channel 5 and 4.
 	hops = []route.Vertex{ctx.aliases["e"], ctx.aliases["c"]}
 	_, err = ctx.router.BuildRoute(
-		noAmt, hops, nil, 40, nil, fn.None[[]byte](),
+		noAmt, hops, nil, 40, fn.None[[32]byte](), fn.None[[]byte](),
 	)
 	require.Error(t, err)
 	noChanErr = ErrNoChannel{}
@@ -1722,7 +1723,7 @@ func TestBuildRoute(t *testing.T) {
 	// policy of channel 3.
 	hops = []route.Vertex{ctx.aliases["b"], ctx.aliases["z"]}
 	rt, err = ctx.router.BuildRoute(
-		noAmt, hops, nil, 40, &payAddr, fn.None[[]byte](),
+		noAmt, hops, nil, 40, fn.Some(payAddr), fn.None[[]byte](),
 	)
 	require.NoError(t, err)
 	checkHops(rt, []uint64{1, 8}, payAddr)
@@ -1736,7 +1737,8 @@ func TestBuildRoute(t *testing.T) {
 	hops = []route.Vertex{ctx.aliases["d"], ctx.aliases["f"]}
 	amt = lnwire.NewMSatFromSatoshis(100)
 	rt, err = ctx.router.BuildRoute(
-		fn.Some(amt), hops, nil, 40, &payAddr, fn.None[[]byte](),
+		fn.Some(amt), hops, nil, 40, fn.Some(payAddr),
+		fn.None[[]byte](),
 	)
 	require.NoError(t, err)
 	checkHops(rt, []uint64{9, 10}, payAddr)
@@ -1752,7 +1754,7 @@ func TestBuildRoute(t *testing.T) {
 	// is a third pass through newRoute in which this gets corrected to end
 	hops = []route.Vertex{ctx.aliases["d"], ctx.aliases["f"]}
 	rt, err = ctx.router.BuildRoute(
-		noAmt, hops, nil, 40, &payAddr, fn.None[[]byte](),
+		noAmt, hops, nil, 40, fn.Some(payAddr), fn.None[[]byte](),
 	)
 	require.NoError(t, err)
 	checkHops(rt, []uint64{9, 10}, payAddr)