From f5c82983e2ed3a624788357fdbcfcc5f8302ad3d Mon Sep 17 00:00:00 2001
From: Wilmer Paulino <wilmer.paulino@gmail.com>
Date: Fri, 29 Jun 2018 16:24:53 -0700
Subject: [PATCH] config: only normalize and resolve tor DNS host if it has
 changed

In the event that the default Tor DNS host wouldn't resolve, it would
prevent `lnd` from starting due to the failed lookup. This should fail
silently as it's only crucial during bootstrapping. However, if the user
has explicitly modified this, we should let them know of the error
immediately.
---
 config.go | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/config.go b/config.go
index 949f2503..2d41a2a0 100644
--- a/config.go
+++ b/config.go
@@ -438,14 +438,18 @@ func loadConfig() (*config, error) {
 	}
 	cfg.Tor.SOCKS = socks.String()
 
-	dns, err := lncfg.ParseAddressString(
-		cfg.Tor.DNS, strconv.Itoa(defaultTorDNSPort),
-		cfg.net.ResolveTCPAddr,
-	)
-	if err != nil {
-		return nil, err
+	// We'll only attempt to normalize and resolve the DNS host if it hasn't
+	// changed, as it doesn't need to be done for the default.
+	if cfg.Tor.DNS != defaultTorDNS {
+		dns, err := lncfg.ParseAddressString(
+			cfg.Tor.DNS, strconv.Itoa(defaultTorDNSPort),
+			cfg.net.ResolveTCPAddr,
+		)
+		if err != nil {
+			return nil, err
+		}
+		cfg.Tor.DNS = dns.String()
 	}
-	cfg.Tor.DNS = dns.String()
 
 	control, err := lncfg.ParseAddressString(
 		cfg.Tor.Control, strconv.Itoa(defaultTorControlPort),