Use Commitment properties to build the correct SharedInput instance

Author: sstone

eclair-core/src/main/scala/fr/acinq/eclair/channel/fsm/Channel.scala

@@ -1024,10 +1024,7 @@ class Channel(val nodeParams: NodeParams, val wallet: OnChainChannelFunder with
             val parentCommitment = d.commitments.latest.commitment
             val localFundingPubKey = nodeParams.channelKeyManager.fundingPublicKey(d.commitments.params.localParams.fundingKeyPath, parentCommitment.fundingTxIndex + 1).publicKey
             val fundingScript = Funding.makeFundingPubKeyScript(localFundingPubKey, msg.fundingPubKey, d.commitments.latest.params.commitmentFormat)
-            val sharedInput = d.commitments.latest.commitInput match {
-              case _: Transactions.InputInfo.TaprootInput => Musig2Input(parentCommitment)
-              case _ => Multisig2of2Input(parentCommitment)
-            }
+            val sharedInput = SharedFundingInput(parentCommitment)
             LiquidityAds.validateRequest(nodeParams.privateKey, d.channelId, fundingScript, msg.feerate, isChannelCreation = false, msg.requestFunding_opt, nodeParams.liquidityAdsConfig.rates_opt, msg.useFeeCredit_opt) match {
               case Left(t) =>
                 log.warning("rejecting splice request with invalid liquidity ads: {}", t.getMessage)
@@ -1085,10 +1082,7 @@ class Channel(val nodeParams: NodeParams, val wallet: OnChainChannelFunder with
         case SpliceStatus.SpliceRequested(cmd, spliceInit) =>
           log.info("our peer accepted our splice request and will contribute {} to the funding transaction", msg.fundingContribution)
           val parentCommitment = d.commitments.latest.commitment
-          val sharedInput = d.commitments.latest.commitInput match {
-            case _: Transactions.InputInfo.TaprootInput => Musig2Input(parentCommitment)
-            case _ => Multisig2of2Input(parentCommitment)
-          }
+          val sharedInput = SharedFundingInput(parentCommitment)
           val fundingParams = InteractiveTxParams(
             channelId = d.channelId,
             isInitiator = true,
@@ -1169,7 +1163,7 @@ class Channel(val nodeParams: NodeParams, val wallet: OnChainChannelFunder with
                     isInitiator = false,
                     localContribution = fundingContribution,
                     remoteContribution = msg.fundingContribution,
-                    sharedInput_opt = Some(Multisig2of2Input(rbf.parentCommitment)),
+                    sharedInput_opt = Some(SharedFundingInput(rbf.parentCommitment)),
                     remoteFundingPubKey = rbf.latestFundingTx.fundingParams.remoteFundingPubKey,
                     localOutputs = rbf.latestFundingTx.fundingParams.localOutputs,
                     lockTime = msg.lockTime,
@@ -1222,7 +1216,7 @@ class Channel(val nodeParams: NodeParams, val wallet: OnChainChannelFunder with
                     isInitiator = true,
                     localContribution = txInitRbf.fundingContribution,
                     remoteContribution = msg.fundingContribution,
-                    sharedInput_opt = Some(Multisig2of2Input(rbf.parentCommitment)),
+                    sharedInput_opt = Some(SharedFundingInput(rbf.parentCommitment)),
                     remoteFundingPubKey = rbf.latestFundingTx.fundingParams.remoteFundingPubKey,
                     localOutputs = rbf.latestFundingTx.fundingParams.localOutputs,
                     lockTime = txInitRbf.lockTime,
@@ -3258,7 +3252,7 @@ class Channel(val nodeParams: NodeParams, val wallet: OnChainChannelFunder with
     val targetFeerate = nodeParams.onChainFeeConf.getFundingFeerate(nodeParams.currentFeeratesForFundingClosing)
     val fundingContribution = InteractiveTxFunder.computeSpliceContribution(
       isInitiator = true,
-      sharedInput = Multisig2of2Input(parentCommitment),
+      sharedInput = SharedFundingInput(parentCommitment),
       spliceInAmount = cmd.additionalLocalFunding,
       spliceOut = cmd.spliceOutputs,
       targetFeerate = targetFeerate)

eclair-core/src/main/scala/fr/acinq/eclair/channel/fund/InteractiveTxBuilder.scala

@@ -109,6 +109,13 @@ object InteractiveTxBuilder {
     // @formatter:on
   }
 
+  object SharedFundingInput {
+    def apply(commitment: Commitment): SharedFundingInput = commitment.commitInput match {
+      case inputInfo: InputInfo.SegwitInput => Multisig2of2Input(inputInfo, commitment.fundingTxIndex, commitment.remoteFundingPubKey)
+      case inputInfo: InputInfo.TaprootInput => Musig2Input(inputInfo, commitment.fundingTxIndex, commitment.remoteFundingPubKey, commitment.localCommit.index)
+    }
+  }
+
   case class Multisig2of2Input(info: InputInfo, fundingTxIndex: Long, remoteFundingPubkey: PublicKey) extends SharedFundingInput {
     override val weight: Int = 388
 
@@ -118,29 +125,12 @@ object InteractiveTxBuilder {
     }
   }
 
-  object Multisig2of2Input {
-    def apply(commitment: Commitment): Multisig2of2Input = Multisig2of2Input(
-      info = commitment.commitInput,
-      fundingTxIndex = commitment.fundingTxIndex,
-      remoteFundingPubkey = commitment.remoteFundingPubKey
-    )
-  }
-
   case class Musig2Input(info: InputInfo, fundingTxIndex: Long, remoteFundingPubkey: PublicKey, commitIndex: Long) extends SharedFundingInput {
     override val weight: Int = 234
 
     override def sign(keyManager: ChannelKeyManager, params: ChannelParams, tx: Transaction): ByteVector64 = ByteVector64.Zeroes
   }
-
-  object Musig2Input {
-    def apply(commitment: Commitment): Musig2Input = Musig2Input(
-      info = commitment.commitInput,
-      fundingTxIndex = commitment.fundingTxIndex,
-      remoteFundingPubkey = commitment.remoteFundingPubKey,
-      commitIndex = commitment.localCommit.index
-    )
-  }
-
+  
   /**
    * @param channelId              id of the channel.
    * @param isInitiator            true if we initiated the protocol, in which case we will pay fees for the shared parts of the transaction.

eclair-core/src/test/scala/fr/acinq/eclair/channel/InteractiveTxBuilderSpec.scala

@@ -86,8 +86,8 @@ class InteractiveTxBuilderSpec extends TestKitBaseClass with AnyFunSuiteLike wit
   }
 
   private def sharedInputs(commitmentA: Commitment, commitmentB: Commitment): (SharedFundingInput, SharedFundingInput) = {
-    val sharedInputA = Multisig2of2Input(commitmentA)
-    val sharedInputB = Multisig2of2Input(commitmentB)
+    val sharedInputA = SharedFundingInput(commitmentA)
+    val sharedInputB = SharedFundingInput(commitmentB)
     (sharedInputA, sharedInputB)
   }