Release v35.2

Closes #177

app/Server/Endpoints/TrackMessagesEndpoint.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Net;
 using System.Text.Json;
@@ -8,6 +9,7 @@ using DHT.Server.Data;
 using DHT.Server.Data.Filters;
 using DHT.Server.Database;
 using DHT.Server.Service;
+using DHT.Utils.Collections;
 using DHT.Utils.Http;
 using Microsoft.AspNetCore.Http;
 
@@ -53,12 +55,16 @@ namespace DHT.Server.Endpoints {
 			Reactions = json.HasKey("reactions") ? ReadReactions(json.RequireArray("reactions", path + ".reactions"), path + ".reactions[]").ToImmutableArray() : ImmutableArray<Reaction>.Empty
 		};
 
+		[SuppressMessage("ReSharper", "ConvertToLambdaExpression")]
 		private static IEnumerable<Attachment> ReadAttachments(JsonElement.ArrayEnumerator array, string path) => array.Select(ele => new Attachment {
 			Id = ele.RequireSnowflake("id", path),
 			Name = ele.RequireString("name", path),
 			Type = ele.HasKey("type") ? ele.RequireString("type", path) : null,
 			Url = ele.RequireString("url", path),
 			Size = (ulong) ele.RequireLong("size", path)
+		}).DistinctByKeyStable(static attachment => {
+			// Some Discord messages have duplicate attachments with the same id for unknown reasons.
+			return attachment.Id;
 		});
 
 		private static IEnumerable<Embed> ReadEmbeds(JsonElement.ArrayEnumerator array, string path) => array.Select(ele => new Embed {

app/Utils/Collections/LinqExtensions.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+
+namespace DHT.Utils.Collections {
+	public static class LinqExtensions {
+		public static IEnumerable<TItem> DistinctByKeyStable<TItem, TKey>(this IEnumerable<TItem> collection, Func<TItem, TKey> getKeyFromItem) where TKey : IEquatable<TKey> {
+			HashSet<TKey>? seenKeys = null;
+			
+			foreach (var item in collection) {
+				seenKeys ??= new HashSet<TKey>();
+				
+				if (seenKeys.Add(getKeyFromItem(item))) {
+					yield return item;
+				}
+			}
+		}
+	}
+}

app/Version.cs

@@ -7,6 +7,6 @@ using DHT.Utils;
 
 namespace DHT.Utils {
 	static class Version {
-		public const string Tag = "35.1.0.0";
+		public const string Tag = "35.2.0.0";
 	}
 }