multi: optionally enable and signal anchor support

Defaults to disabled.

feature/default_sets.go

@@ -43,4 +43,8 @@ var defaultSetDesc = setDesc{
 		SetNodeAnn: {}, // N
 		SetInvoice: {}, // 9
 	},
+	lnwire.AnchorsOptional: {
+		SetInit:    {}, // I
+		SetNodeAnn: {}, // N
+	},
 }

feature/deps.go

@@ -55,6 +55,9 @@ var deps = depDesc{
 	lnwire.MPPOptional: {
 		lnwire.PaymentAddrOptional: {},
 	},
+	lnwire.AnchorsOptional: {
+		lnwire.StaticRemoteKeyOptional: {},
+	},
 }
 
 // ValidateDeps asserts that a feature vector sets all features and their

feature/manager.go

@@ -17,6 +17,9 @@ type Config struct {
 	// NoStaticRemoteKey unsets any optional or required StaticRemoteKey
 	// bits from all feature sets.
 	NoStaticRemoteKey bool
+
+	// NoAnchors unsets any bits signaling support for anchor outputs.
+	NoAnchors bool
 }
 
 // Manager is responsible for generating feature vectors for different requested
@@ -76,6 +79,10 @@ func newManager(cfg Config, desc setDesc) (*Manager, error) {
 			raw.Unset(lnwire.StaticRemoteKeyOptional)
 			raw.Unset(lnwire.StaticRemoteKeyRequired)
 		}
+		if cfg.NoAnchors {
+			raw.Unset(lnwire.AnchorsOptional)
+			raw.Unset(lnwire.AnchorsRequired)
+		}
 
 		// Ensure that all of our feature sets properly set any
 		// dependent features.