Prevent remote map searches overwriting local or generated state.

OpenRA.Game/Map/MapCache.cs

@@ -235,7 +235,7 @@ namespace OpenRA
 				.ToList();
 
 			foreach (var uid in queryUids)
-				previews[uid].UpdateRemoteSearch(MapStatus.Searching, null, null);
+				previews[uid].BeginRemoteSearch();
 
 			Task.Run(async () =>
 			{
@@ -251,29 +251,21 @@ namespace OpenRA
 						try
 						{
 							var result = await client.GetStreamAsync(url);
-							var yaml = MiniYaml.FromStream(result, url, stringPool: stringPool);
+							foreach (var kv in MiniYaml.FromStream(result, url, stringPool: stringPool))
-							foreach (var kv in yaml)
+								previews[kv.Key].CompleteRemoteSearch(kv.Value, mapDetailsReceived);
-								previews[kv.Key].UpdateRemoteSearch(MapStatus.DownloadAvailable, kv.Value, mapDetailsReceived);
-
-							foreach (var uid in batchUids)
-							{
-								var p = previews[uid];
-								if (p.Status != MapStatus.DownloadAvailable)
-									p.UpdateRemoteSearch(MapStatus.Unavailable, null, null);
-							}
 						}
 						catch (Exception e)
 						{
 							Log.Write("debug", "Remote map query failed with error:");
 							Log.Write("debug", e);
 							Log.Write("debug", $"URL was: {url}");
+						}
 
-							foreach (var uid in batchUids)
+						foreach (var uid in batchUids)
-							{
+						{
-								var p = previews[uid];
+							var p = previews[uid];
-								p.UpdateRemoteSearch(MapStatus.Unavailable, null, null);
+							if (p.Status == MapStatus.Searching)
-								mapQueryFailed?.Invoke(p);
+								p.CompleteRemoteSearch(null, mapQueryFailed);
-							}
 						}
 					}
 				}

OpenRA.Game/Map/MapPreview.cs

@@ -196,6 +196,7 @@ namespace OpenRA
 		}
 
 		static readonly CPos[] NoSpawns = [];
+		readonly object syncRoot = new();
 		readonly MapCache cache;
 		readonly ModData modData;
 		IReadOnlyPackage package;
@@ -452,28 +453,37 @@ namespace OpenRA
 			newData.ModifiedDate = File.GetLastWriteTime(p.Name);
 
 			// Assign the new data atomically
-			innerData = newData;
+			// Local maps have higher precedence than remote/generated maps,
+			// so should always replace their metadata
+			lock (syncRoot)
+				innerData = newData;
 		}
 
-		public void UpdateRemoteSearch(MapStatus status, MiniYaml yaml, Action<MapPreview> parseMetadata = null)
+		public void BeginRemoteSearch()
 		{
 			var newData = innerData.Clone();
-			newData.Status = status;
 			newData.Class = MapClassification.Remote;
+			newData.Status = MapStatus.Searching;
 
-			if (status == MapStatus.DownloadAvailable)
+			// We may have been resolved to a local/generated map by another
+			// async task. Make sure we don't stomp over their state!
+			lock (syncRoot)
+				if (innerData.Class == MapClassification.Unknown || innerData.Class == MapClassification.Remote)
+					innerData = newData;
+		}
+
+		public void CompleteRemoteSearch(MiniYaml yaml, Action<MapPreview> parseMetadata = null)
+		{
+			var newData = innerData.Clone();
+			newData.Class = MapClassification.Remote;
+			newData.Status = MapStatus.Unavailable;
+
+			if (yaml != null)
 			{
 				try
 				{
 					var r = FieldLoader.Load<RemoteMapData>(yaml);
-
+					newData.Status = r.downloading ? MapStatus.DownloadAvailable : MapStatus.Unavailable;
-					// Map download has been disabled server side
-					if (!r.downloading)
-					{
-						newData.Status = MapStatus.Unavailable;
-						return;
-					}
-
 					newData.Title = r.title;
 					newData.Categories = r.categories;
 					newData.Author = r.author;
@@ -520,19 +530,27 @@ namespace OpenRA
 				{
 					Log.Write("debug", "Failed parsing mapserver response:");
 					Log.Write("debug", e);
+					newData.Status = MapStatus.Unavailable;
 				}
+			}
 
-				// Commit updated data before running the callbacks
+			// We may have been resolved to a local/generated map by another
-				innerData = newData;
+			// async task. Make sure we don't stomp over their state!
+			MapClassification mapClassification;
+			lock (syncRoot)
+			{
+				mapClassification = innerData.Class;
+				if (mapClassification == MapClassification.Remote)
+					innerData = newData;
+			}
 
+			if (mapClassification == MapClassification.Remote)
+			{
 				if (innerData.Preview != null)
 					cache.CacheMinimap(this);
 
 				parseMetadata?.Invoke(this);
 			}
-
-			// Update the status and class unconditionally
-			innerData = newData;
 		}
 
 		public void Install(string mapRepositoryUrl)
@@ -605,7 +623,11 @@ namespace OpenRA
 
 		public void Invalidate()
 		{
-			innerData.Status = MapStatus.Unavailable;
+			lock (syncRoot)
+			{
+				innerData.Class = MapClassification.Unknown;
+				innerData.Status = MapStatus.Unavailable;
+			}
 		}
 
 		public void Dispose()