Merge branch '6.0' into 7.0

# Conflicts:
#	Extensions/Xtensive.Orm.BulkOperations/Internals/Operation.cs
#	Orm/Xtensive.Orm/Tuples/Packed/TupleLayout.cs
#	Version.props

Author: alex-kulakov

ChangeLog/6.0.8_Z_Final.txt

@@ -0,0 +1,5 @@
+[main] Resolved DateTimeOffset reading issues for certain queries with JOIN
+[main] Improved compiled queries work with entity parameters
+[main] Coalesce operator with local Entity/Structure instance in it is prohibited to prevent wrong query results
+[main] Ternary operator with local Entity/Structure instance in it is prohibited to prevent wrong query results
+[bulkoperations] Ressuracted check for transaction to prevent unrollbackable changes

Extensions/Xtensive.Orm.BulkOperations/Internals/Operation.cs

@@ -1,4 +1,4 @@
-// Copyright (C) 2019-2020 Xtensive LLC.
+// Copyright (C) 2019-2021 Xtensive LLC.
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
@@ -50,11 +50,7 @@ public async Task<int> ExecuteAsync(CancellationToken token = default)
       return value;
     }
 
-    private void EnsureTransactionIsStarted()
-    {
-      var accessor = QueryProvider.Session.Services.Demand<DirectSqlAccessor>();
-      _ = accessor.Transaction;
-    }
+    protected void EnsureTransactionIsStarted() => Transaction.Require(QueryProvider.Session);
 
     protected abstract int ExecuteInternal();
 

Orm/Xtensive.Orm.Tests.Core/Tuples/DateTimeOffsetTupleTest.cs

@@ -0,0 +1,56 @@
+// Copyright (C) 2021 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.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using NUnit.Framework;
+using Xtensive.Tuples.Packed;
+using Xtensive.Orm.Tests;
+
+namespace Xtensive.Tuples
+{
+  [TestFixture]
+  public sealed class DateTimeOffsetTupleTest
+  {
+    [Test]
+    public void OnlyDateTimeOffsetFieldsTest()
+    {
+      var minLength = 30;
+      var maxLength = 200;
+      var iterationCount = 1000;
+      var rnd = RandomManager.CreateRandom();
+      var generator = InstanceGeneratorProvider.Default.GetInstanceGenerator<DateTimeOffset>();
+      for (var i = 0; i < iterationCount; i++) {
+        var count = rnd.Next(maxLength - minLength);
+
+        var fields = new Type[count];
+        var data = new DateTimeOffset[count];
+        for (var j = 0; j < count; j++) {
+          data[j] = generator.GetInstance(rnd);
+          fields[j] = typeof(DateTimeOffset);
+        }
+
+        // Testing writes (untyped)
+        var tuple1 = Tuple.Create(fields);
+        Assert.That(tuple1, Is.InstanceOf<PackedTuple>());
+        for (var j = 0; j < count; j++)
+          tuple1.SetValue(j, (object) data[j]);
+        // Testing reads (untyped)
+        for (var j = 0; j < count; j++)
+          Assert.AreEqual(data[j], tuple1.GetValue(j));
+
+        // Testing writes (untyped)
+        var tuple2 = Tuple.Create(fields);
+        Assert.That(tuple2, Is.InstanceOf<PackedTuple>());
+        for (var j = 0; j < count; j++)
+          tuple2.SetValue(j, data[j]);
+        for (var j = 0; j < count; j++)
+          Assert.AreEqual(data[j], tuple2.GetValue<DateTimeOffset>(j));
+      }
+    }
+  }
+}

Orm/Xtensive.Orm.Tests.Framework/Internals/DateTimeOffsetInstanceGenerator.cs

@@ -0,0 +1,32 @@
+// Copyright (C) 2021 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
+using System;
+
+namespace Xtensive.Orm.Tests
+{
+  [Serializable]
+  internal class DateTimeOffsetInstanceGenerator : InstanceGeneratorBase<DateTimeOffset>
+  {
+    private readonly IInstanceGenerator<DateTime> dateTimeInstanceGenerator;
+
+    public override DateTimeOffset GetInstance(Random random)
+    {
+      var randomDateTime = dateTimeInstanceGenerator.GetInstance(random);
+      var randomTimeSpan = new TimeSpan(random.Next(0, 10), random.Next(0, 60), 0);
+
+      var signBase = random.Next(-100, 100);
+      if (signBase != 0 && (signBase / Math.Abs(signBase)) < 0)
+        randomTimeSpan = randomTimeSpan.Negate();
+
+      return new DateTimeOffset(randomDateTime, randomTimeSpan);
+    }
+
+    public DateTimeOffsetInstanceGenerator(IInstanceGeneratorProvider provider)
+      : base(provider)
+    {
+      dateTimeInstanceGenerator = provider.GetInstanceGenerator<DateTime>();
+    }
+  }
+}