p2p/discover: fix a race where table loop would self-lookup before returning from constructor

p2p/discover/table.go

@@ -119,7 +119,6 @@ func newTable(t transport, db *enode.DB, bootnodes []*enode.Node, log log.Logger
 	tab.seedRand()
 	tab.loadSeedNodes()
 
-	go tab.loop()
 	return tab, nil
 }
 

p2p/discover/table_util_test.go

@@ -42,6 +42,7 @@ func init() {
 func newTestTable(t transport) (*Table, *enode.DB) {
 	db, _ := enode.OpenDB("")
 	tab, _ := newTable(t, db, nil, log.Root())
+	go tab.loop()
 	return tab, db
 }
 

p2p/discover/v4_udp.go

@@ -253,6 +253,7 @@ func ListenV4(c UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv4, error) {
 		return nil, err
 	}
 	t.tab = tab
+	go tab.loop()
 
 	t.wg.Add(2)
 	go t.loop()