lncli: add chan_point flag to closechannel command

cmd/lncli/commands.go

@@ -39,6 +39,9 @@ const (
 	defaultUtxoMinConf = 1
 )
 
+var errBadChanPoint = errors.New("expecting chan_point to be in format of: " +
+	"txid:index")
+
 func getContext() context.Context {
 	shutdownInterceptor, err := signal.Intercept()
 	if err != nil {
@@ -719,6 +722,12 @@ var closeChannelCommand = cli.Command{
 			Usage: "the output index for the funding output of the funding " +
 				"transaction",
 		},
+		cli.StringFlag{
+			Name: "chan_point",
+			Usage: "(optional) the channel point. If set, " +
+				"funding_txid and output_index flags and " +
+				"positional arguments will be ignored",
+		},
 		cli.BoolFlag{
 			Name:  "force",
 			Usage: "attempt an uncooperative closure",
@@ -1183,10 +1192,19 @@ func abandonChannel(ctx *cli.Context) error {
 // line. Both named options as well as unnamed parameters are supported.
 func parseChannelPoint(ctx *cli.Context) (*lnrpc.ChannelPoint, error) {
 	channelPoint := &lnrpc.ChannelPoint{}
+	var err error
 
 	args := ctx.Args()
 
 	switch {
+	case ctx.IsSet("chan_point"):
+		channelPoint, err = parseChanPoint(ctx.String("chan_point"))
+		if err != nil {
+			return nil, fmt.Errorf("unable to parse chan_point: "+
+				"%v", err)
+		}
+		return channelPoint, nil
+
 	case ctx.IsSet("funding_txid"):
 		channelPoint.FundingTxid = &lnrpc.ChannelPoint_FundingTxidStr{
 			FundingTxidStr: ctx.String("funding_txid"),
@@ -1984,9 +2002,8 @@ var updateChannelPolicyCommand = cli.Command{
 
 func parseChanPoint(s string) (*lnrpc.ChannelPoint, error) {
 	split := strings.Split(s, ":")
-	if len(split) != 2 {
-		return nil, fmt.Errorf("expecting chan_point to be in format of: " +
-			"txid:index")
+	if len(split) != 2 || len(split[0]) == 0 || len(split[1]) == 0 {
+		return nil, errBadChanPoint
 	}
 
 	index, err := strconv.ParseInt(split[1], 10, 32)
@@ -2077,7 +2094,7 @@ func updateChannelPolicy(ctx *cli.Context) error {
 	if chanPointStr != "" {
 		chanPoint, err = parseChanPoint(chanPointStr)
 		if err != nil {
-			return fmt.Errorf("unable to parse chan point: %v", err)
+			return fmt.Errorf("unable to parse chan_point: %v", err)
 		}
 	}
 
@@ -2227,7 +2244,7 @@ func exportChanBackup(ctx *cli.Context) error {
 	if chanPointStr != "" {
 		chanPointRPC, err := parseChanPoint(chanPointStr)
 		if err != nil {
-			return err
+			return fmt.Errorf("unable to parse chan_point: %v", err)
 		}
 
 		chanBackup, err := client.ExportChannelBackup(