loopd: fix nil ptr derefence for monitor

Reason for the crash was an unpopulated HtlcAddress field.

client.go

@@ -113,14 +113,61 @@ func NewClient(dbDir string, serverAddress string, insecure bool,
 	return client, cleanup, nil
 }
 
-// FetchLoopOutSwaps returns a list of all swaps currently in the database.
-func (s *Client) FetchLoopOutSwaps() ([]*loopdb.LoopOut, error) {
-	return s.Store.FetchLoopOutSwaps()
-}
+// FetchSwaps returns all loop in and out swaps currently in the database.
+func (s *Client) FetchSwaps() ([]*SwapInfo, error) {
+	loopOutSwaps, err := s.Store.FetchLoopOutSwaps()
+	if err != nil {
+		return nil, err
+	}
 
-// FetchLoopInSwaps returns a list of all swaps currently in the database.
-func (s *Client) FetchLoopInSwaps() ([]*loopdb.LoopIn, error) {
-	return s.Store.FetchLoopInSwaps()
+	loopInSwaps, err := s.Store.FetchLoopInSwaps()
+	if err != nil {
+		return nil, err
+	}
+
+	swaps := make([]*SwapInfo, 0, len(loopInSwaps)+len(loopOutSwaps))
+
+	for _, swp := range loopOutSwaps {
+		htlc, err := swap.NewHtlc(
+			swp.Contract.CltvExpiry, swp.Contract.SenderKey,
+			swp.Contract.ReceiverKey, swp.Hash, swap.HtlcP2WSH,
+			s.lndServices.ChainParams,
+		)
+		if err != nil {
+			return nil, err
+		}
+
+		swaps = append(swaps, &SwapInfo{
+			SwapType:     TypeOut,
+			SwapContract: swp.Contract.SwapContract,
+			State:        swp.State(),
+			SwapHash:     swp.Hash,
+			LastUpdate:   swp.LastUpdateTime(),
+			HtlcAddress:  htlc.Address,
+		})
+	}
+
+	for _, swp := range loopInSwaps {
+		htlc, err := swap.NewHtlc(
+			swp.Contract.CltvExpiry, swp.Contract.SenderKey,
+			swp.Contract.ReceiverKey, swp.Hash, swap.HtlcNP2WSH,
+			s.lndServices.ChainParams,
+		)
+		if err != nil {
+			return nil, err
+		}
+
+		swaps = append(swaps, &SwapInfo{
+			SwapType:     TypeIn,
+			SwapContract: swp.Contract.SwapContract,
+			State:        swp.State(),
+			SwapHash:     swp.Hash,
+			LastUpdate:   swp.LastUpdateTime(),
+			HtlcAddress:  htlc.Address,
+		})
+	}
+
+	return swaps, nil
 }
 
 // Run is a blocking call that executes all swaps. Any pending swaps are

cmd/loopd/daemon.go

@@ -32,6 +32,7 @@ func daemon(config *config) error {
 		config.SwapServer = testnetServer
 	}
 
+	// Create an instance of the loop client library.
 	swapClient, cleanup, err := getClient(
 		config.Network, config.SwapServer, config.Insecure, &lnd.LndServices,
 	)
@@ -40,35 +41,14 @@ func daemon(config *config) error {
 	}
 	defer cleanup()
 
-	// Before starting the client, build an in-memory view of all swaps.
-	// This view is used to update newly connected clients with the most
-	// recent swaps.
-	loopOutSwaps, err := swapClient.FetchLoopOutSwaps()
+	// Retrieve all currently existing swaps from the database.
+	swapsList, err := swapClient.FetchSwaps()
 	if err != nil {
 		return err
 	}
-	for _, swap := range loopOutSwaps {
-		swaps[swap.Hash] = loop.SwapInfo{
-			SwapType:     loop.TypeOut,
-			SwapContract: swap.Contract.SwapContract,
-			State:        swap.State(),
-			SwapHash:     swap.Hash,
-			LastUpdate:   swap.LastUpdateTime(),
-		}
-	}
 
-	loopInSwaps, err := swapClient.FetchLoopInSwaps()
-	if err != nil {
-		return err
-	}
-	for _, swap := range loopInSwaps {
-		swaps[swap.Hash] = loop.SwapInfo{
-			SwapType:     loop.TypeIn,
-			SwapContract: swap.Contract.SwapContract,
-			State:        swap.State(),
-			SwapHash:     swap.Hash,
-			LastUpdate:   swap.LastUpdateTime(),
-		}
+	for _, s := range swapsList {
+		swaps[s.SwapHash] = *s
 	}
 
 	// Instantiate the loopd gRPC server.

cmd/loopd/view.go

@@ -42,7 +42,7 @@ func view(config *config) error {
 }
 
 func viewOut(swapClient *loop.Client, chainParams *chaincfg.Params) error {
-	swaps, err := swapClient.FetchLoopOutSwaps()
+	swaps, err := swapClient.Store.FetchLoopOutSwaps()
 	if err != nil {
 		return err
 	}
@@ -88,7 +88,7 @@ func viewOut(swapClient *loop.Client, chainParams *chaincfg.Params) error {
 }
 
 func viewIn(swapClient *loop.Client, chainParams *chaincfg.Params) error {
-	swaps, err := swapClient.FetchLoopInSwaps()
+	swaps, err := swapClient.Store.FetchLoopInSwaps()
 	if err != nil {
 		return err
 	}