Allow 0 failure amt on importmc

cmd/lncli/cmd_import_mission_control.go

@@ -66,8 +66,9 @@ func importMissionControl(ctx *cli.Context) error {
 		return fmt.Errorf("please provide amount in msat: %w", err)
 	}
 
-	if amt <= 0 {
-		return errors.New("amount must be >0")
+	// Allow 0 value as failure amount.
+	if !ctx.IsSet("failure") && amt <= 0 {
+		return errors.New("success amount must be >0")
 	}
 
 	client := routerrpc.NewRouterClient(conn)

docs/release-notes/release-notes-0.18.1.md

@@ -27,7 +27,15 @@
 # Improvements
 ## Functional Updates
 ## RPC Updates
+
+* [`xImportMissionControl`](https://github.com/lightningnetwork/lnd/pull/8779) 
+  now accepts `0` failure amounts.
+
 ## lncli Updates
+
+* [`importmc`](https://github.com/lightningnetwork/lnd/pull/8779) now accepts
+  `0` failure amounts.
+
 ## Code Health
 ## Breaking Changes
 ## Performance Improvements
@@ -40,3 +48,5 @@
 ## Tooling and Documentation
 
 # Contributors (Alphabetical Order)
+
+* Bufo

lnrpc/routerrpc/router_server.go

@@ -1137,6 +1137,7 @@ func toPairSnapshot(pairResult *PairHistory) (*routing.MissionControlPairSnapsho
 		lnwire.MilliSatoshi(pairResult.History.FailAmtMsat),
 		btcutil.Amount(pairResult.History.FailAmtSat),
 		pairResult.History.FailTime,
+		true,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("%v invalid failure: %w", pairPrefix,
@@ -1147,6 +1148,7 @@ func toPairSnapshot(pairResult *PairHistory) (*routing.MissionControlPairSnapsho
 		lnwire.MilliSatoshi(pairResult.History.SuccessAmtMsat),
 		btcutil.Amount(pairResult.History.SuccessAmtSat),
 		pairResult.History.SuccessTime,
+		false,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("%v invalid success: %w", pairPrefix,
@@ -1174,9 +1176,11 @@ func toPairSnapshot(pairResult *PairHistory) (*routing.MissionControlPairSnapsho
 }
 
 // getPair validates the values provided for a mission control result and
-// returns the msat amount and timestamp for it.
+// returns the msat amount and timestamp for it. `isFailure` can be used to
+// default values to 0 instead of returning an error.
 func getPair(amtMsat lnwire.MilliSatoshi, amtSat btcutil.Amount,
-	timestamp int64) (lnwire.MilliSatoshi, time.Time, error) {
+	timestamp int64, isFailure bool) (lnwire.MilliSatoshi, time.Time,
+	error) {
 
 	amt, err := getMsatPairValue(amtMsat, amtSat)
 	if err != nil {
@@ -1189,16 +1193,21 @@ func getPair(amtMsat lnwire.MilliSatoshi, amtSat btcutil.Amount,
 	)
 
 	switch {
+	// If a timestamp and amount if provided, return those values.
 	case timeSet && amountSet:
 		return amt, time.Unix(timestamp, 0), nil
 
-	case timeSet && !amountSet:
+	// Return an error if it does have a timestamp without an amount, and
+	// it's not expected to be a failure.
+	case !isFailure && timeSet && !amountSet:
 		return 0, time.Time{}, errors.New("non-zero timestamp " +
-			"requires non-zero amount")
+			"requires non-zero amount for success pairs")
 
-	case !timeSet && amountSet:
-		return 0, time.Time{}, errors.New("non-zero amount requires " +
-			"non-zero timestamp")
+	// Return an error if it does have an amount without a timestamp, and
+	// it's not expected to be a failure.
+	case !isFailure && !timeSet && amountSet:
+		return 0, time.Time{}, errors.New("non-zero amount for " +
+			"success pairs requires non-zero timestamp")
 
 	default:
 		return 0, time.Time{}, nil