Keep the loop to allow resizing more than once.

commands.go

@@ -1661,8 +1661,10 @@ func (cli *DockerCli) monitorTtySize(id string) error {
 	sigchan := make(chan os.Signal, 1)
 	signal.Notify(sigchan, syscall.SIGWINCH)
 	go func() {
-		<-sigchan
-		cli.resizeTty(id)
+		for {
+			<-sigchan
+			cli.resizeTty(id)
+		}
 	}()
 	return nil
 }