DLC Subsystem. Fix bug at the edges of interval.

lnutil/dlclib.go

@@ -452,26 +452,49 @@ func SettlementTx(c *DlcContract, d DlcContractDivision,
 	feeOurs := feeEach
 	feeTheirs := feeEach
 	valueOurs := d.ValueOurs
-	// We don't have enough to pay for a fee. We get 0, our contract partner
-	// pays the rest of the fee
-	if valueOurs < feeEach {
-		feeOurs = valueOurs
-		valueOurs = 0
-	} else {
-		valueOurs = d.ValueOurs - feeOurs
-	}
+
+	// This code leads to errors at edges of the interval so I disable it
+
+	// // We don't have enough to pay for a fee. We get 0, our contract partner
+	// // pays the rest of the fee
+	// if valueOurs < feeEach {
+	// 	feeOurs = valueOurs
+	// 	valueOurs = 0
+	// } else {
+	// 	valueOurs = d.ValueOurs - feeOurs
+	// }
 	totalContractValue := c.TheirFundingAmount + c.OurFundingAmount
 	valueTheirs := totalContractValue - d.ValueOurs
 
-	if valueTheirs < feeEach {
-		feeTheirs = valueTheirs
-		valueTheirs = 0
-		feeOurs = totalFee - feeTheirs
+
+	// This code leads to errors at edges of the interval so I disable it
+
+	// if valueTheirs < feeEach {
+	// 	feeTheirs = valueTheirs
+	// 	valueTheirs = 0
+	// 	feeOurs = totalFee - feeTheirs
+	// 	valueOurs = d.ValueOurs - feeOurs
+	// } else {
+	// 	valueTheirs -= feeTheirs
+	// }
+
+
+	// There is a simplified code but it works at edges of the interval.
+
+	if valueOurs == 0 {
+		valueTheirs = valueTheirs - totalFee
+	}else{
 		valueOurs = d.ValueOurs - feeOurs
-	} else {
+	}
+
+	if valueTheirs == 0 {
+		valueOurs = valueOurs - totalFee
+	}else{
 		valueTheirs -= feeTheirs
 	}
 
+
+
 	var buf bytes.Buffer
 	binary.Write(&buf, binary.BigEndian, uint64(0))
 	binary.Write(&buf, binary.BigEndian, uint64(0))

qln/dlc.go

@@ -609,46 +609,58 @@ func (nd *LitNode) SettleContract(cIdx uint64, oracleValue int64, oracleSig [32]
 		return [32]byte{}, [32]byte{}, err
 	}
 
-	// TODO: Claim the contract settlement output back to our wallet - otherwise the peer can claim it after locktime.
-	txClaim := wire.NewMsgTx()
-	txClaim.Version = 2
 
-	settleOutpoint := wire.OutPoint{Hash: settleTx.TxHash(), Index: 0}
-	txClaim.AddTxIn(wire.NewTxIn(&settleOutpoint, nil, nil))
+	if ( d.ValueOurs != 0){
 
-	addr, err := wal.NewAdr()
-	txClaim.AddTxOut(wire.NewTxOut(d.ValueOurs-1000, lnutil.DirectWPKHScriptFromPKH(addr))) // todo calc fee - fee is double here because the contract output already had the fee deducted in the settlement TX
+		fee := int64(500)
+
+		// TODO: Claim the contract settlement output back to our wallet - otherwise the peer can claim it after locktime.
+		txClaim := wire.NewMsgTx()
+		txClaim.Version = 2
 
-	kg.Step[2] = UseContractPayoutBase
-	privSpend, _ := wal.GetPriv(kg)
+		settleOutpoint := wire.OutPoint{Hash: settleTx.TxHash(), Index: 0}
+		txClaim.AddTxIn(wire.NewTxIn(&settleOutpoint, nil, nil))
 
-	pubSpend := wal.GetPub(kg)
-	privOracle, pubOracle := koblitz.PrivKeyFromBytes(koblitz.S256(), oracleSig[:])
-	privContractOutput := lnutil.CombinePrivateKeys(privSpend, privOracle)
+		addr, err := wal.NewAdr()
+		txClaim.AddTxOut(wire.NewTxOut(settleTx.TxOut[0].Value-fee, lnutil.DirectWPKHScriptFromPKH(addr))) // todo calc fee - fee is double here because the contract output already had the fee deducted in the settlement TX
 
-	var pubOracleBytes [33]byte
-	copy(pubOracleBytes[:], pubOracle.SerializeCompressed())
-	var pubSpendBytes [33]byte
-	copy(pubSpendBytes[:], pubSpend.SerializeCompressed())
+		kg.Step[2] = UseContractPayoutBase
+		privSpend, _ := wal.GetPriv(kg)
 
-	settleScript := lnutil.DlcCommitScript(c.OurPayoutBase, pubOracleBytes, c.TheirPayoutBase, 5)
-	err = nd.SignClaimTx(txClaim, settleTx.TxOut[0].Value, settleScript, privContractOutput, false)
-	if err != nil {
-		logging.Errorf("SettleContract SignClaimTx err %s", err.Error())
-		return [32]byte{}, [32]byte{}, err
-	}
+		pubSpend := wal.GetPub(kg)
+		privOracle, pubOracle := koblitz.PrivKeyFromBytes(koblitz.S256(), oracleSig[:])
+		privContractOutput := lnutil.CombinePrivateKeys(privSpend, privOracle)
 
-	// Claim TX should be valid here, so publish it.
-	err = wal.DirectSendTx(txClaim)
-	if err != nil {
-		logging.Errorf("SettleContract DirectSendTx (claim) err %s", err.Error())
-		return [32]byte{}, [32]byte{}, err
-	}
+		var pubOracleBytes [33]byte
+		copy(pubOracleBytes[:], pubOracle.SerializeCompressed())
+		var pubSpendBytes [33]byte
+		copy(pubSpendBytes[:], pubSpend.SerializeCompressed())
+
+		settleScript := lnutil.DlcCommitScript(c.OurPayoutBase, pubOracleBytes, c.TheirPayoutBase, 5)
+		err = nd.SignClaimTx(txClaim, settleTx.TxOut[0].Value, settleScript, privContractOutput, false)
+		if err != nil {
+			logging.Errorf("SettleContract SignClaimTx err %s", err.Error())
+			return [32]byte{}, [32]byte{}, err
+		}
+
+		// Claim TX should be valid here, so publish it.
+		err = wal.DirectSendTx(txClaim)
+		if err != nil {
+			logging.Errorf("SettleContract DirectSendTx (claim) err %s", err.Error())
+			return [32]byte{}, [32]byte{}, err
+		}
+
+		c.Status = lnutil.ContractStatusClosed
+		err = nd.DlcManager.SaveContract(c)
+		if err != nil {
+			return [32]byte{}, [32]byte{}, err
+		}
+		return settleTx.TxHash(), txClaim.TxHash(), nil
+
+	}else{
+
+		return settleTx.TxHash(), [32]byte{}, nil
 
-	c.Status = lnutil.ContractStatusClosed
-	err = nd.DlcManager.SaveContract(c)
-	if err != nil {
-		return [32]byte{}, [32]byte{}, err
 	}
-	return settleTx.TxHash(), txClaim.TxHash(), nil
+
 }