Fix AutoFlushIfRequired result when flush was performed in Auto flush mode (nhibernate#3188)

Author: kostgr

src/NHibernate.Test/Async/NHSpecificTest/NH3583/AutoFlushFixture.cs

@@ -8,16 +8,20 @@
 //------------------------------------------------------------------------------
 
 
+using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Transactions;
 using NHibernate.Cfg.MappingSchema;
-using NHibernate.Linq;
+using NHibernate.Impl;
 using NHibernate.Mapping.ByCode;
 using NUnit.Framework;
+using NHibernate.Linq;
 
 namespace NHibernate.Test.NHSpecificTest.NH3583
 {
 	using System.Threading.Tasks;
+	using System.Threading;
 	[TestFixture]
 	public class AutoFlushFixtureAsync : TestCaseMappingByCode
 	{
@@ -61,6 +65,24 @@ public async Task ShouldAutoFlushWhenInExplicitTransactionAsync()
 				Assert.That(result.Count, Is.EqualTo(1));
 			}
 		}
+		
+		[Test]
+		public async Task AutoFlushIfRequiredShouldReturnTrueAsync()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var e1 = new Entity { Name = "Bob" };
+				await (session.SaveAsync(e1));
+
+				var implementor = session as AbstractSessionImpl;
+				var spaces = new HashSet<string> { "Entity" };
+				Debug.Assert(implementor != null, nameof(implementor) + " != null");
+				Assert.That(session.FlushMode, Is.EqualTo(FlushMode.Auto), "Issue is only presented in FlushMode.Auto");
+				Assert.That(await (implementor.AutoFlushIfRequiredAsync(spaces, CancellationToken.None)), Is.True, "AutoFlushIfRequired should have reported, that the flush has been done.");
+			}
+		}
+		
 
 		[Test]
 		public async Task ShouldAutoFlushWhenInDistributedTransactionAsync()

src/NHibernate.Test/NHSpecificTest/NH3583/AutoFlushFixture.cs

@@ -1,7 +1,9 @@
-using System.Linq;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
 using System.Transactions;
 using NHibernate.Cfg.MappingSchema;
-using NHibernate.Linq;
+using NHibernate.Impl;
 using NHibernate.Mapping.ByCode;
 using NUnit.Framework;
 
@@ -50,6 +52,24 @@ public void ShouldAutoFlushWhenInExplicitTransaction()
 				Assert.That(result.Count, Is.EqualTo(1));
 			}
 		}
+		
+		[Test]
+		public void AutoFlushIfRequiredShouldReturnTrue()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var e1 = new Entity { Name = "Bob" };
+				session.Save(e1);
+
+				var implementor = session as AbstractSessionImpl;
+				var spaces = new HashSet<string> { "Entity" };
+				Debug.Assert(implementor != null, nameof(implementor) + " != null");
+				Assert.That(session.FlushMode, Is.EqualTo(FlushMode.Auto), "Issue is only presented in FlushMode.Auto");
+				Assert.That(implementor.AutoFlushIfRequired(spaces), Is.True, "AutoFlushIfRequired should have reported, that the flush has been done.");
+			}
+		}
+		
 
 		[Test]
 		public void ShouldAutoFlushWhenInDistributedTransaction()

src/NHibernate/Async/Event/Default/DefaultAutoFlushEventListener.cs

@@ -39,7 +39,8 @@ public virtual async Task OnAutoFlushAsync(AutoFlushEvent @event, CancellationTo
 
 					await (FlushEverythingToExecutionsAsync(@event, cancellationToken)).ConfigureAwait(false);
 
-					if (FlushIsReallyNeeded(@event, source))
+					var flushIsReallyNeeded = FlushIsReallyNeeded(@event, source);
+					if (flushIsReallyNeeded)
 					{
 						if (log.IsDebugEnabled())
 							log.Debug("Need to execute flush");
@@ -61,7 +62,7 @@ public virtual async Task OnAutoFlushAsync(AutoFlushEvent @event, CancellationTo
 						source.ActionQueue.ClearFromFlushNeededCheck(oldSize);
 					}
 
-					@event.FlushRequired = FlushIsReallyNeeded(@event, source);
+					@event.FlushRequired = flushIsReallyNeeded;
 				}
 			}
 		}

src/NHibernate/Event/Default/DefaultAutoFlushEventListener.cs

@@ -31,7 +31,8 @@ public virtual void OnAutoFlush(AutoFlushEvent @event)
 
 					FlushEverythingToExecutions(@event);
 
-					if (FlushIsReallyNeeded(@event, source))
+					var flushIsReallyNeeded = FlushIsReallyNeeded(@event, source);
+					if (flushIsReallyNeeded)
 					{
 						if (log.IsDebugEnabled())
 							log.Debug("Need to execute flush");
@@ -53,7 +54,7 @@ public virtual void OnAutoFlush(AutoFlushEvent @event)
 						source.ActionQueue.ClearFromFlushNeededCheck(oldSize);
 					}
 
-					@event.FlushRequired = FlushIsReallyNeeded(@event, source);
+					@event.FlushRequired = flushIsReallyNeeded;
 				}
 			}
 		}