Sentinel with PubSub deadlocks on Close

[danilobuerger]

When using the FailoverClient (Sentinel) with PubSub, calling Close will deadlock.

Expected Behavior

Close will close the PubSub and return.

Current Behavior

Close does not return.

Steps to Reproduce

func main() {
	client := redis.NewFailoverClient(&redis.FailoverOptions{
		MasterName:    "...",
		SentinelAddrs: []string{"..."},
	})

	pubSub := client.Subscribe(context.Background())
	pubSub.Channel()
	time.Sleep(1 * time.Second)
	log.Println("Subscribed")

	pubSub.Close()
	log.Println("Closed")
}

Version: 9.5.1