Fix `displayIndex` not being correctly set to `-1` after last expiry date

osu.Game.Tests/Visual/Menus/TestSceneOnlineMenuBanner.cs

@@ -144,7 +144,41 @@ public void TestMultipleImages()
         }
 
         [Test]
-        public void TestExpiry()
+        public void TestFutureSingle()
+        {
+            AddStep("set image with time constraints", () => onlineMenuBanner.Current.Value = new APIMenuContent
+            {
+                Images = new[]
+                {
+                    new APIMenuImage
+                    {
+                        Image = @"https://assets.ppy.sh/main-menu/project-loved-2@2x.png",
+                        Url = @"https://osu.ppy.sh/home/news/2023-12-21-project-loved-december-2023",
+                        Begins = DateTimeOffset.Now.AddSeconds(2),
+                        Expires = DateTimeOffset.Now.AddSeconds(5),
+                    },
+                },
+            });
+
+            AddUntilStep("wait for no image shown", () => !onlineMenuBanner.ChildrenOfType<OnlineMenuBanner.MenuImage>().Any(i => i.IsPresent));
+
+            AddUntilStep("wait for one image shown", () =>
+            {
+                var images = onlineMenuBanner.ChildrenOfType<OnlineMenuBanner.MenuImage>();
+
+                if (images.Count() != 1)
+                    return false;
+
+                var image = images.Single();
+
+                return image.IsPresent && image.Image.Url == "https://osu.ppy.sh/home/news/2023-12-21-project-loved-december-2023";
+            });
+
+            AddUntilStep("wait for no image shown", () => !onlineMenuBanner.ChildrenOfType<OnlineMenuBanner.MenuImage>().Any(i => i.IsPresent));
+        }
+
+        [Test]
+        public void TestExpiryMultiple()
         {
             AddStep("set multiple images, second expiring soon", () => onlineMenuBanner.Current.Value = new APIMenuContent
             {

osu.Game/Screens/Menu/OnlineMenuBanner.cs

@@ -127,14 +127,15 @@ private void showNext()
             {
                 int previousIndex = displayIndex;
 
-                if (displayIndex == -1)
-                    displayIndex = 0;
-
                 // To handle expiration simply, arrange all images in best-next order.
                 // Fade in the first valid one, then handle fading out the last if required.
                 var currentRotation = content
-                                      .Skip(displayIndex + 1)
+                                      .Skip(Math.Max(0, previousIndex) + 1)
-                                      .Concat(content.Take(displayIndex + 1));
+                                      .Concat(content.Take(Math.Max(0, previousIndex) + 1));
+
+                // After the loop, displayIndex will be the new valid index or -1 if
+                // none valid.
+                displayIndex = -1;
 
                 foreach (var image in currentRotation)
                 {