Cached query captures object in closure

Author: SergeiPavlov

Orm/Xtensive.Orm.Tests/Issues/Issue_DelayedQueryCapture.cs

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+// Copyright (C) 2022 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
+using System;
+using System.Collections;
+using System.Diagnostics;
+using System.Linq;
+using System.Linq.Dynamic;
+using System.Reflection;
+using System.Threading;
+using NUnit.Framework;
+using Xtensive.Caching;
+using Xtensive.Orm.Configuration;
+using Xtensive.Orm.Tests.Issues.Issue0628_ExecuteFutureScalarError_Model;
+
+namespace Xtensive.Orm.Tests.Issues
+{
+  namespace Issue_DelayedQueryCapture_Model
+  {
+    [HierarchyRoot]
+    class Item : Entity
+    {
+      [Field, Key]
+      public int Id { get; private set; }
+
+      [Field]
+      public int Tag { get; set; }
+    }
+  }
+
+  [Serializable]
+  public class Issue_DelayedQueryCapture : AutoBuildTest
+  {
+    public class OtherService
+    {
+      public static volatile int InstanceCount;
+
+      public int N;
+
+      public OtherService()
+      {
+        Interlocked.Increment(ref InstanceCount);
+      }
+
+      ~OtherService()
+      {
+        Interlocked.Decrement(ref InstanceCount);
+      }
+    }
+
+
+    protected override DomainConfiguration BuildConfiguration()
+    {
+      var config = base.BuildConfiguration();
+      config.Types.Register(typeof(Item).Assembly, typeof(Item).Namespace);
+      return config;
+    }
+
+    [Test]
+    public void DelayedQueryCapture()
+    {
+      using (var session = Domain.OpenSession())
+      using (var t = session.OpenTransaction()) {
+        var item = new Item() { Tag = 10 };
+        DelayedQuery(session);
+        t.Complete();
+      }
+      GC.Collect();
+      Thread.Sleep(1000);
+      GC.Collect();
+      Assert.AreEqual(0, OtherService.InstanceCount);
+    }
+
+    private void DelayedQuery(Session session)
+    {
+      var ids = new[] { 1, 2 };
+      var otherService = new OtherService();
+
+      var items = session.Query.CreateDelayedQuery(q =>
+                from t in q.All<Item>()
+                where t.Id.In(ids)
+                select t).ToArray();
+
+      var bb1 = items
+          .Select(a => new {
+            a.Id,
+            A = new {
+              B = otherService.N == a.Id
+            },
+          });
+    }
+  }
+}