avoid sending to closed Events/UniqueEvents channels.

relaypool.go

@@ -152,6 +152,7 @@ func (r *RelayPool) Add(url string, policy RelayPoolPolicy) error {
 						continue
 					}
 
+					if !subscription.stopped {
 						subscription.Events <- EventMessage{
 							Relay: nm,
 							Event: event,
@@ -159,6 +160,7 @@ func (r *RelayPool) Add(url string, policy RelayPoolPolicy) error {
 					}
 				}
 			}
+		}
 	}()
 
 	return nil

subscription.go

@@ -9,6 +9,8 @@ type Subscription struct {
 
 	started      bool
 	UniqueEvents chan Event
+
+	stopped bool
 }
 
 type EventMessage struct {
@@ -24,6 +26,7 @@ func (subscription Subscription) Unsub() {
 		})
 	}
 
+	subscription.stopped = true
 	if subscription.Events != nil {
 		close(subscription.Events)
 	}
@@ -57,9 +60,11 @@ func (subscription Subscription) startHandlingUnique() {
 			continue
 		}
 		seen[em.Event.ID] = struct{}{}
+		if !subscription.stopped {
 			subscription.UniqueEvents <- em.Event
 		}
 	}
+}
 
 func (subscription Subscription) removeRelay(relay string) {
 	if conn, ok := subscription.relays[relay]; ok {