fix(dns): fix panic when using DNS_KEEP_NAMESERVER

internal/dns/run.go

@@ -37,7 +37,6 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 			if err == nil {
 				l.backoffTime = defaultBackoffTime
 				l.logger.Info("ready")
-				l.signalOrSetStatus(constants.Running)
 				break
 			}
 
@@ -54,6 +53,7 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 			l.logAndWait(ctx, err)
 			settings = l.GetSettings()
 		}
+		l.signalOrSetStatus(constants.Running)
 
 		settings = l.GetSettings()
 		if !*settings.KeepNameserver && !*settings.DoT.Enabled {
@@ -74,15 +74,19 @@ func (l *Loop) runWait(ctx context.Context, runError <-chan error) (exitLoop boo
 	for {
 		select {
 		case <-ctx.Done():
+			if !*l.GetSettings().KeepNameserver {
 				l.stopServer()
 				// TODO revert OS and Go nameserver when exiting
+			}
 			return true
 		case <-l.stop:
 			l.userTrigger = true
 			l.logger.Info("stopping")
+			if !*l.GetSettings().KeepNameserver {
 				const fallback = false
 				l.useUnencryptedDNS(fallback)
 				l.stopServer()
+			}
 			l.stopped <- struct{}{}
 		case <-l.start:
 			l.userTrigger = true