From 250cc0ec0f453e43d8a8f66a47c236fb800cec4f Mon Sep 17 00:00:00 2001
From: Eugene Bujak <hmage@hmage.net>
Date: Thu, 6 Dec 2018 00:29:38 +0300
Subject: [PATCH] config -- Avoid deleting existing dns section if someone
 removes schema_version from yaml file.

---
 config.go  | 1 +
 upgrade.go | 6 ++++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/config.go b/config.go
index 8facc405..407fcc7a 100644
--- a/config.go
+++ b/config.go
@@ -72,6 +72,7 @@ var config = configuration{
 		{Filter: dnsfilter.Filter{ID: 3}, Enabled: false, URL: "https://hosts-file.net/ad_servers.txt", Name: "hpHosts - Ad and Tracking servers only"},
 		{Filter: dnsfilter.Filter{ID: 4}, Enabled: false, URL: "http://www.malwaredomainlist.com/hostslist/hosts.txt", Name: "MalwareDomainList.com Hosts List"},
 	},
+	SchemaVersion: currentSchemaVersion,
 }
 
 // Loads configuration from the YAML file
diff --git a/upgrade.go b/upgrade.go
index 1b8c6e34..21d7686d 100644
--- a/upgrade.go
+++ b/upgrade.go
@@ -126,8 +126,10 @@ func upgradeSchema1to2(diskConfig *map[string]interface{}) error {
 		}
 	}
 
-	(*diskConfig)["dns"] = (*diskConfig)["coredns"]
-	delete((*diskConfig), "coredns")
+	if _, ok := (*diskConfig)["dns"]; !ok {
+		(*diskConfig)["dns"] = (*diskConfig)["coredns"]
+		delete((*diskConfig), "coredns")
+	}
 	(*diskConfig)["schema_version"] = 2
 
 	return nil