Fix NH-3572: Avoid calling AfterTransactionCompletion twice when a distributed transaction is rolled back.

Author: oskarb

src/NHibernate.Test/SystemTransactions/TransactionNotificationFixture.cs

@@ -65,7 +65,7 @@ public void Rollback()
 			{
 			}
 			Assert.AreEqual(0, interceptor.beforeTransactionCompletionCalled);
-			Assert.AreEqual(2, interceptor.afterTransactionCompletionCalled);
+			Assert.AreEqual(1, interceptor.afterTransactionCompletionCalled);
 		}
 
 		[Test]
@@ -109,16 +109,13 @@ public void OneTransactionScopesInsideOneSession()
 		}
 
 
-		[Description("NH2128")]
+		[Description("NH2128, NH3572")]
 		[Theory]
 		public void ShouldNotifyAfterDistributedTransaction(bool doCommit)
 		{
 			// Note: For distributed transaction, calling Close() on the session isn't
 			// supported, so we don't need to test that scenario.
 
-			if (!doCommit)
-				Assert.Ignore("Rollback on distributed transaction doubles the number of calls to AfterTransactionCompletion - see NH-3572.");
-
 			var interceptor = new RecordingInterceptor();
 			ISession s1 = null;
 			ISession s2 = null;

src/NHibernate/Transaction/AdoNetWithDistributedTransactionFactory.cs

@@ -147,8 +147,9 @@ void IEnlistmentNotification.Rollback(Enlistment enlistment)
 			{
 				using (new SessionIdLoggingContext(sessionImplementor.SessionId))
 				{
-					sessionImplementor.AfterTransactionCompletion(false, null);
 					logger.Debug("rolled back DTC transaction");
+					// Currently AfterTransactionCompletion is called by the handler for the TransactionCompleted event.
+					//sessionImplementor.AfterTransactionCompletion(false, null);
 					enlistment.Done();
 					IsInActiveTransaction = false;
 				}