Fix FetchLazyProperties updates modified properties

src/NHibernate.Test/Async/FetchLazyProperties/FetchLazyPropertiesFixture.cs

@@ -274,6 +274,45 @@ public async Task TestLinqFetchAllPropertiesAsync()
 			AssertFetchAllProperties(person);
 		}
 
+		[TestCase(true)]
+		[TestCase(false)]
+		public async Task TestLinqFetchAllProperties_WhenLazyPropertyChangedAsync(bool initLazyPropertyFetchGroup)
+		{
+			Person person;
+			using (var s = OpenSession())
+			{
+				person = await (s.GetAsync<Person>(1));
+				if (initLazyPropertyFetchGroup)
+					CollectionAssert.AreEqual(new byte[] { 0 }, person.Image);
+
+				person.Image = new byte[] { 1, 2, 3 };
+
+				var allPersons = await (s.Query<Person>().FetchLazyProperties().ToListAsync());
+				// After execute FetchLazyProperties(), I expected to see that the person.Image would be { 1, 2, 3 }.
+				// Because I changed this person.Image manually, I didn't want to lose those changes.
+				// But test failed. Оld value returned { 0 }.
+				CollectionAssert.AreEqual(new byte[] { 1, 2, 3 }, person.Image);
+			}
+		}
+
+		[TestCase(true)]
+		[TestCase(false)]
+		public async Task TestLinqFetchProperty_WhenLazyPropertyChangedAsync(bool initLazyPropertyFetchGroup)
+		{
+			Person person;
+			using (var s = OpenSession())
+			{
+				person = await (s.GetAsync<Person>(1));
+				if (initLazyPropertyFetchGroup)
+					CollectionAssert.AreEqual(new byte[] { 0 }, person.Image);
+
+				person.Image = new byte[] { 1, 2, 3 };
+
+				var allPersons = await (s.Query<Person>().Fetch(x => x.Image).ToListAsync());
+				CollectionAssert.AreEqual(new byte[] { 1, 2, 3 }, person.Image);
+			}
+		}
+
 		private static void AssertFetchAllProperties(Person person)
 		{
 			Assert.That(person, Is.Not.Null);

src/NHibernate.Test/FetchLazyProperties/FetchLazyPropertiesFixture.cs

@@ -263,6 +263,45 @@ public void TestLinqFetchAllProperties()
 			AssertFetchAllProperties(person);
 		}
 
+		[TestCase(true)]
+		[TestCase(false)]
+		public void TestLinqFetchAllProperties_WhenLazyPropertyChanged(bool initLazyPropertyFetchGroup)
+		{
+			Person person;
+			using (var s = OpenSession())
+			{
+				person = s.Get<Person>(1);
+				if (initLazyPropertyFetchGroup)
+					CollectionAssert.AreEqual(new byte[] { 0 }, person.Image);
+
+				person.Image = new byte[] { 1, 2, 3 };
+
+				var allPersons = s.Query<Person>().FetchLazyProperties().ToList();
+				// After execute FetchLazyProperties(), I expected to see that the person.Image would be { 1, 2, 3 }.
+				// Because I changed this person.Image manually, I didn't want to lose those changes.
+				// But test failed. Оld value returned { 0 }.
+				CollectionAssert.AreEqual(new byte[] { 1, 2, 3 }, person.Image);
+			}
+		}
+
+		[TestCase(true)]
+		[TestCase(false)]
+		public void TestLinqFetchProperty_WhenLazyPropertyChanged(bool initLazyPropertyFetchGroup)
+		{
+			Person person;
+			using (var s = OpenSession())
+			{
+				person = s.Get<Person>(1);
+				if (initLazyPropertyFetchGroup)
+					CollectionAssert.AreEqual(new byte[] { 0 }, person.Image);
+
+				person.Image = new byte[] { 1, 2, 3 };
+
+				var allPersons = s.Query<Person>().Fetch(x => x.Image).ToList();
+				CollectionAssert.AreEqual(new byte[] { 1, 2, 3 }, person.Image);
+			}
+		}
+
 		private static void AssertFetchAllProperties(Person person)
 		{
 			Assert.That(person, Is.Not.Null);

src/NHibernate/Async/Loader/Loader.cs

@@ -797,8 +797,13 @@ private async Task UpdateLazyPropertiesFromResultSetAsync(DbDataReader rs, int i
 				? persister.EntityMetamodel.BytecodeEnhancementMetadata.GetUninitializedLazyProperties(entry.LoadedState)
 				: persister.EntityMetamodel.BytecodeEnhancementMetadata.GetUninitializedLazyProperties(obj);
 
-			var updateLazyProperties = fetchLazyProperties?.Intersect(uninitializedProperties).ToArray();
-			if (updateLazyProperties?.Length == 0)
+			if (uninitializedProperties.Count == 0)
+				return;
+
+			var updateLazyProperties = fetchAllProperties
+				? uninitializedProperties.ToArray()
+				: fetchLazyProperties.Intersect(uninitializedProperties).ToArray();
+			if (updateLazyProperties.Length == 0)
 			{
 				return; // No new lazy properites were loaded
 			}
@@ -814,7 +819,7 @@ private async Task UpdateLazyPropertiesFromResultSetAsync(DbDataReader rs, int i
 				? EntityAliases[i].SuffixedPropertyAliases
 				: GetSubclassEntityAliases(i, persister);
 
-			if (!await (persister.InitializeLazyPropertiesAsync(rs, id, obj, cols, updateLazyProperties, fetchAllProperties, session, cancellationToken)).ConfigureAwait(false))
+			if (!await (persister.InitializeLazyPropertiesAsync(rs, id, obj, cols, updateLazyProperties, false, session, cancellationToken)).ConfigureAwait(false))
 			{
 				return;
 			}

src/NHibernate/Loader/Loader.cs

@@ -1203,8 +1203,13 @@ private void UpdateLazyPropertiesFromResultSet(DbDataReader rs, int i, object ob
 				? persister.EntityMetamodel.BytecodeEnhancementMetadata.GetUninitializedLazyProperties(entry.LoadedState)
 				: persister.EntityMetamodel.BytecodeEnhancementMetadata.GetUninitializedLazyProperties(obj);
 
-			var updateLazyProperties = fetchLazyProperties?.Intersect(uninitializedProperties).ToArray();
-			if (updateLazyProperties?.Length == 0)
+			if (uninitializedProperties.Count == 0)
+				return;
+
+			var updateLazyProperties = fetchAllProperties
+				? uninitializedProperties.ToArray()
+				: fetchLazyProperties.Intersect(uninitializedProperties).ToArray();
+			if (updateLazyProperties.Length == 0)
 			{
 				return; // No new lazy properites were loaded
 			}
@@ -1220,7 +1225,7 @@ private void UpdateLazyPropertiesFromResultSet(DbDataReader rs, int i, object ob
 				? EntityAliases[i].SuffixedPropertyAliases
 				: GetSubclassEntityAliases(i, persister);
 
-			if (!persister.InitializeLazyProperties(rs, id, obj, cols, updateLazyProperties, fetchAllProperties, session))
+			if (!persister.InitializeLazyProperties(rs, id, obj, cols, updateLazyProperties, false, session))
 			{
 				return;
 			}