SERVER-28248 Fix move construction of NamespaceMetadataChangeNotifications::ScopedNotification

2 files changed, 28 insertions, 1 deletions

diff --git a/src/mongo/db/s/namespace_metadata_change_notifications.h b/src/mongo/db/s/namespace_metadata_change_notifications.h
index 832e18a9976..8fd98fe6640 100644
--- a/src/mongo/db/s/namespace_metadata_change_notifications.h
+++ b/src/mongo/db/s/namespace_metadata_change_notifications.h
@@ -59,13 +59,19 @@ public:
      * out of scope, if it has not been signalled yet.
      */
     class ScopedNotification {
+        MONGO_DISALLOW_COPYING(ScopedNotification);
+
     public:
         ScopedNotification(NamespaceMetadataChangeNotifications* notifications,
                            std::shared_ptr<NotificationToken> token)
             : _notifications(notifications), _token(std::move(token)) {}
 
+        ScopedNotification(ScopedNotification&&) = default;
+
         ~ScopedNotification() {
-            _notifications->_unregisterNotificationToken(std::move(_token));
+            if (_token) {
+                _notifications->_unregisterNotificationToken(std::move(_token));
+            }
         }
 
         void get(OperationContext* opCtx) {
diff --git a/src/mongo/db/s/namespace_metadata_change_notifications_test.cpp b/src/mongo/db/s/namespace_metadata_change_notifications_test.cpp
index c43a8c9774a..66b4e28c33b 100644
--- a/src/mongo/db/s/namespace_metadata_change_notifications_test.cpp
+++ b/src/mongo/db/s/namespace_metadata_change_notifications_test.cpp
@@ -95,5 +95,26 @@ TEST_F(NamespaceMetadataChangeNotificationsTest, GiveUpWaitingForNotify) {
     notifications.notifyChange(kNss);
 }
 
+TEST_F(NamespaceMetadataChangeNotificationsTest, MoveConstructionWaitForNotify) {
+    NamespaceMetadataChangeNotifications notifications;
+
+    auto scopedNotif = notifications.createNotification(kNss);
+    auto movedScopedNotif = std::move(scopedNotif);
+
+    {
+        auto opCtx = client()->makeOperationContext();
+        opCtx->setDeadlineAfterNowBy(Milliseconds{0});
+        ASSERT_THROWS_CODE(
+            movedScopedNotif.get(opCtx.get()), UserException, ErrorCodes::ExceededTimeLimit);
+    }
+
+    notifications.notifyChange(kNss);
+
+    {
+        auto opCtx = client()->makeOperationContext();
+        movedScopedNotif.get(opCtx.get());
+    }
+}
+
 }  // namespace
 }  // namespace mongo