From 63a3ce13e4ca028062eb55797561b7dcd4dafb6d Mon Sep 17 00:00:00 2001
From: laplamgor <laplamgor@gmail.com>
Date: Mon, 15 Jan 2018 15:12:48 +0800
Subject: [PATCH] Fix a crash when not enough results to shuffle.

---
 .../Services/AnimePersonalization.cs          | 22 ++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/PRPR/BooruViewer/Services/AnimePersonalization.cs b/PRPR/BooruViewer/Services/AnimePersonalization.cs
index 709fcfe..f67a62e 100644
--- a/PRPR/BooruViewer/Services/AnimePersonalization.cs
+++ b/PRPR/BooruViewer/Services/AnimePersonalization.cs
@@ -89,7 +89,27 @@ public static async Task<string> SetBackgroundImageAsync(FilteredCollection<Post
             Random rnd = new Random();
             int pointer = rnd.Next((int)postShuffle);
 
-            var post = await GetPostAtAsync(posts, pointer);
+            // Load as many post as possible until reaching the pointer
+            while ((pointer >= posts.Count) && (posts.HasMoreItems))
+            {
+                await posts.LoadMoreItemsAsync(1);
+            }
+
+            if (posts.Count == 0)
+            {
+                // No result at all, cannot update background
+                return "";
+            }
+
+            if (posts.Count - 1 < pointer)
+            {
+                // Not enough posts to shuffle, shuffle for a lower amount of posts
+                pointer = rnd.Next((int)posts.Count - 1);
+            }
+
+            // Select a post
+            var post = posts[pointer];
+
             var previewBuffer = await (new Windows.Web.Http.HttpClient()).GetBufferAsync(new Uri(post.PreviewUrl));
             var largeBufferUrl = "";
             int largeWidth = 0;