fix(advanced-search): A/F - worker filter is exception-safe, skips deleted entities, guards empty expressions

Projects/UOContent.Tests/Tests/Engines/AdvancedSearch/AdvancedSearchWorkerTests.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Collections.Concurrent;
+using Server;
+using Server.Engines.AdvancedSearch;
+using Server.Items;
+using Server.Tests;
+using Xunit;
+
+namespace UOContent.Tests;
+
+[Collection("Sequential UOContent Tests")]
+public class AdvancedSearchWorkerTests
+{
+    // An item whose property test path will throw when evaluated.
+    private sealed class ThrowingItem : Item
+    {
+        public ThrowingItem() : base(0x1) { }
+        public ThrowingItem(Serial s) : base(s) { }
+        public string Boom => throw new InvalidOperationException("boom");
+    }
+
+    [Fact]
+    public void Worker_FilterThrows_DoesNotEscape_ReturnsNoMatch()
+    {
+        var worker = new AdvancedSearchThreadWorker();
+        var results = new ConcurrentQueue<AdvancedSearchResult>();
+        var ignore = new ConcurrentQueue<IEntity>();
+        var filter = new AdvancedSearchFilter
+        {
+            FilterPropertyTest = true,
+            PropertyTest = "Boom=1", // reflection GetValue -> throws
+        };
+
+        var item = new ThrowingItem();
+
+        try
+        {
+            worker.Wake(new WorldLocation(Point3D.Zero, Map.Felucca), filter, results, ignore);
+            worker.Push(item);
+            worker.Sleep(); // drains; must not crash the test process
+
+            Assert.Empty(results);
+        }
+        finally
+        {
+            item.Delete();
+            worker.Exit();
+        }
+    }
+
+    [Fact]
+    public void Worker_DeletedEntity_IsSkipped()
+    {
+        var worker = new AdvancedSearchThreadWorker();
+        var results = new ConcurrentQueue<AdvancedSearchResult>();
+        var ignore = new ConcurrentQueue<IEntity>();
+        var filter = new AdvancedSearchFilter(); // no filters -> everything matches
+
+        var item = new Item(0x1);
+        item.Delete();
+
+        try
+        {
+            worker.Wake(new WorldLocation(Point3D.Zero, Map.Felucca), filter, results, ignore);
+            worker.Push(item);
+            worker.Sleep();
+
+            Assert.Empty(results);
+        }
+        finally
+        {
+            worker.Exit();
+        }
+    }
+}

Projects/UOContent/Engines/Advanced Search/AdvancedSearchThreadWorker.cs

@@ -3,6 +3,7 @@ using System.Collections.Concurrent;
 using System.Reflection;
 using System.Threading;
 using Server.Items;
+using Server.Logging;
 using Server.Mobiles;
 using Server.Multis;
 
@@ -10,6 +11,8 @@ namespace Server.Engines.AdvancedSearch;
 
 public class AdvancedSearchThreadWorker
 {
+    private static readonly ILogger _logger = LogFactory.GetLogger(typeof(AdvancedSearchThreadWorker));
+
     private readonly Thread _thread;
     private readonly AutoResetEvent _startEvent; // Main thread tells the thread to start working
     private readonly AutoResetEvent _stopEvent; // Main thread waits for the worker finish draining
@@ -101,6 +104,24 @@ public class AdvancedSearchThreadWorker
     }
 
     private AdvancedSearchResult DoEntitySearch(IEntity entity)
+    {
+        if (entity == null || entity.Deleted)
+        {
+            return null;
+        }
+
+        try
+        {
+            return DoEntitySearchCore(entity);
+        }
+        catch (Exception ex)
+        {
+            _logger.Warning(ex, "AdvancedSearch: filter threw for {Entity}; skipping", entity);
+            return null;
+        }
+    }
+
+    private AdvancedSearchResult DoEntitySearchCore(IEntity entity)
     {
         if (_filter.HideValidInternalMap)
         {
@@ -317,6 +338,12 @@ public class AdvancedSearchThreadWorker
 
     private static bool EvaluateSingleExpression(IEntity entity, ReadOnlySpan<char> expression)
     {
+        expression = expression.Trim();
+        if (expression.Length == 0)
+        {
+            return false;
+        }
+
         var negate = false;
         if (expression[0] == '~')
         {