[FIXED] Clear status listeners map on SubscriptionClosed event

Signed-off-by: Piotr Piotrowski <piotr@synadia.com>

nats.go

@@ -33,6 +33,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"runtime"
+	"slices"
 	"strconv"
 	"strings"
 	"sync"
@@ -4686,7 +4687,7 @@ func (s *Subscription) registerStatusChangeListener(status SubStatus, ch chan Su
 // will not block. Lock should be held entering.
 func (s *Subscription) sendStatusEvent(status SubStatus) {
 	for ch, statuses := range s.statListeners {
-		if !containsStatus(statuses, status) {
+		if !slices.Contains(statuses, status) {
 			continue
 		}
 		// only send event if someone's listening
@@ -4694,21 +4695,18 @@ func (s *Subscription) sendStatusEvent(status SubStatus) {
 		case ch <- status:
 		default:
 		}
-		if status == SubscriptionClosed {
+	}
+	// After sending SubscriptionClosed status to all listeners,
+	// close all channels and clear the map to prevent future
+	// sends to closed channels that could cause panics
+	if status == SubscriptionClosed {
+		for ch := range s.statListeners {
 			close(ch)
 		}
+		s.statListeners = nil
 	}
 }
 
-func containsStatus(statuses []SubStatus, status SubStatus) bool {
-	for _, s := range statuses {
-		if s == status {
-			return true
-		}
-	}
-	return false
-}
-
 // changeSubStatus changes subscription status and sends events
 // to all listeners. Lock should be held entering.
 func (s *Subscription) changeSubStatus(status SubStatus) {