Merge pull request #1104 from Bahtya/fix/pubsub-connection-leak

fix: close pubsub connection on Subscribe error in CancelationPubSub

internal/rdb/rdb.go

@@ -1488,6 +1488,7 @@ func (r *RDB) CancelationPubSub() (*redis.PubSub, error) {
 	pubsub := r.client.Subscribe(ctx, base.CancelChannel)
 	_, err := pubsub.Receive(ctx)
 	if err != nil {
+		pubsub.Close()
 		return nil, errors.E(op, errors.Unknown, fmt.Sprintf("redis pubsub receive error: %v", err))
 	}
 	return pubsub, nil

internal/rdb/rdb_test.go

@@ -3274,6 +3274,29 @@ func TestCancelationPubSub(t *testing.T) {
 	mu.Unlock()
 }
 
+func TestCancelationPubSubReceiveError(t *testing.T) {
+	// Use a client connected to a non-existent Redis server to trigger
+	// a Receive() error. This verifies that the pubsub connection is
+	// closed on error, preventing connection leaks.
+	client := redis.NewClient(&redis.Options{
+		Addr: "localhost:0", // invalid port — connection will fail
+	})
+	r := NewRDB(client)
+	defer r.Close()
+
+	pubsub, err := r.CancelationPubSub()
+	if err == nil {
+		// If no error, we must clean up the pubsub.
+		if pubsub != nil {
+			pubsub.Close()
+		}
+		t.Fatal("(*RDB).CancelationPubSub() expected to return an error when redis is unreachable")
+	}
+	if pubsub != nil {
+		t.Error("(*RDB).CancelationPubSub() expected nil pubsub on error")
+	}
+}
+
 func TestWriteResult(t *testing.T) {
 	r := setup(t)
 	defer r.Close()