feature: use +100 staging bit for taproot channels

In this commit, we carry out a new notion introduced during a recent
spec meeting to use a feature bit plus 100 before the feature has been
finalized in the spec.

We split into the Final and Staging bits.

funding/commitment_type_negotiation.go

@@ -241,10 +241,13 @@ func explicitNegotiateCommitmentType(channelType lnwire.ChannelType, local,
 		return lnwallet.CommitmentTypeTweakless, nil
 
 	// Simple taproot channels only.
-	case channelFeatures.OnlyContains(lnwire.SimpleTaprootChannelsRequired):
+	case channelFeatures.OnlyContains(
+		lnwire.SimpleTaprootChannelsRequiredStaging,
+	):
 
 		if !hasFeatures(
-			local, remote, lnwire.SimpleTaprootChannelsOptional,
+			local, remote,
+			lnwire.SimpleTaprootChannelsOptionalStaging,
 		) {
 
 			return 0, errUnsupportedChannelType
@@ -254,13 +257,13 @@ func explicitNegotiateCommitmentType(channelType lnwire.ChannelType, local,
 
 	// Simple taproot channels with scid only.
 	case channelFeatures.OnlyContains(
-		lnwire.SimpleTaprootChannelsRequired,
+		lnwire.SimpleTaprootChannelsRequiredStaging,
 		lnwire.ScidAliasRequired,
 	):
 
 		if !hasFeatures(
 			local, remote,
-			lnwire.SimpleTaprootChannelsOptional,
+			lnwire.SimpleTaprootChannelsOptionalStaging,
 			lnwire.ScidAliasOptional,
 		) {
 
@@ -271,13 +274,13 @@ func explicitNegotiateCommitmentType(channelType lnwire.ChannelType, local,
 
 	// Simple taproot channels with zero conf only.
 	case channelFeatures.OnlyContains(
-		lnwire.SimpleTaprootChannelsRequired,
+		lnwire.SimpleTaprootChannelsRequiredStaging,
 		lnwire.ZeroConfRequired,
 	):
 
 		if !hasFeatures(
 			local, remote,
-			lnwire.SimpleTaprootChannelsOptional,
+			lnwire.SimpleTaprootChannelsOptionalStaging,
 			lnwire.ZeroConfOptional,
 		) {
 
@@ -288,14 +291,14 @@ func explicitNegotiateCommitmentType(channelType lnwire.ChannelType, local,
 
 	// Simple taproot channels with scid and zero conf.
 	case channelFeatures.OnlyContains(
-		lnwire.SimpleTaprootChannelsRequired,
+		lnwire.SimpleTaprootChannelsRequiredStaging,
 		lnwire.ZeroConfRequired,
 		lnwire.ScidAliasRequired,
 	):
 
 		if !hasFeatures(
 			local, remote,
-			lnwire.SimpleTaprootChannelsOptional,
+			lnwire.SimpleTaprootChannelsOptionalStaging,
 			lnwire.ZeroConfOptional,
 		) {
 
@@ -320,16 +323,6 @@ func implicitNegotiateCommitmentType(local,
 	remote *lnwire.FeatureVector) (*lnwire.ChannelType,
 	lnwallet.CommitmentType) {
 
-	// If both peers are signalling support for taproot chanenls, then
-	// we'll use that type.
-	if hasFeatures(local, remote, lnwire.SimpleTaprootChannelsOptional) {
-		chanType := lnwire.ChannelType(*lnwire.NewRawFeatureVector(
-			lnwire.SimpleTaprootChannelsRequired,
-		))
-
-		return &chanType, lnwallet.CommitmentTypeSimpleTaproot
-	}
-
 	// If both peers are signalling support for anchor commitments with
 	// zero-fee HTLC transactions, we'll use this type.
 	if hasFeatures(local, remote, lnwire.AnchorsZeroFeeHtlcTxOptional) {

funding/manager.go

@@ -4077,7 +4077,9 @@ func (f *Manager) newChanAnnouncement(localPubKey,
 		log.Debugf("Applying taproot feature bit to "+
 			"ChannelAnnouncement for %v", chanID)
 
-		chanAnn.Features.Set(lnwire.SimpleTaprootChannelsRequired)
+		chanAnn.Features.Set(
+			lnwire.SimpleTaprootChannelsRequiredStaging,
+		)
 	}
 
 	// The chanFlags field indicates which directed edge of the channel is

funding/manager_test.go

@@ -742,7 +742,7 @@ func isTaprootChanType(chanType *lnwire.ChannelType) bool {
 	featVec := lnwire.RawFeatureVector(*chanType)
 
 	return featVec.IsSet(
-		lnwire.SimpleTaprootChannelsRequired,
+		lnwire.SimpleTaprootChannelsRequiredStaging,
 	)
 }
 
@@ -1423,7 +1423,7 @@ func testNormalWorkflow(t *testing.T, chanType *lnwire.ChannelType) {
 			lnwire.ExplicitChannelTypeOptional,
 			lnwire.StaticRemoteKeyOptional,
 			lnwire.AnchorsZeroFeeHtlcTxOptional,
-			lnwire.SimpleTaprootChannelsOptional,
+			lnwire.SimpleTaprootChannelsOptionalStaging,
 		}
 		alice.localFeatures = featureBits
 		alice.remoteFeatures = featureBits
@@ -1543,7 +1543,7 @@ func TestFundingManagerNormalWorkflow(t *testing.T) {
 	t.Parallel()
 
 	taprootChanType := lnwire.ChannelType(*lnwire.NewRawFeatureVector(
-		lnwire.SimpleTaprootChannelsRequired,
+		lnwire.SimpleTaprootChannelsRequiredStaging,
 	))
 
 	testCases := []struct {
@@ -4460,7 +4460,7 @@ func testZeroConf(t *testing.T, chanType *lnwire.ChannelType) {
 		lnwire.ExplicitChannelTypeOptional,
 		lnwire.StaticRemoteKeyOptional,
 		lnwire.AnchorsZeroFeeHtlcTxOptional,
-		lnwire.SimpleTaprootChannelsOptional,
+		lnwire.SimpleTaprootChannelsOptionalStaging,
 	}
 	alice.localFeatures = featureBits
 	alice.remoteFeatures = featureBits
@@ -4476,7 +4476,7 @@ func testZeroConf(t *testing.T, chanType *lnwire.ChannelType) {
 	if isTaprootChanType(chanType) {
 		channelTypeBits = []lnwire.FeatureBit{
 			lnwire.ZeroConfRequired,
-			lnwire.SimpleTaprootChannelsRequired,
+			lnwire.SimpleTaprootChannelsRequiredStaging,
 		}
 	} else {
 		channelTypeBits = []lnwire.FeatureBit{
@@ -4708,7 +4708,7 @@ func TestFundingManagerZeroConf(t *testing.T) {
 	t.Parallel()
 
 	taprootChanType := lnwire.ChannelType(*lnwire.NewRawFeatureVector(
-		lnwire.SimpleTaprootChannelsRequired,
+		lnwire.SimpleTaprootChannelsRequiredStaging,
 	))
 
 	testCases := []struct {