From 038ca826b0979de43c1afad56db4afc98a367399 Mon Sep 17 00:00:00 2001
From: Mike-E <michael@dragonspark.network>
Date: Mon, 28 Sep 2020 05:07:11 -0400
Subject: [PATCH] Scoped refereence encounter counter to per-writer.

---
 .../References/ReferenceEncounters.cs         | 34 ++++++++++-------
 .../Issue454Tests.cs                          | 38 +++++++++++++++++++
 2 files changed, 58 insertions(+), 14 deletions(-)
 create mode 100644 test/ExtendedXmlSerializer.Tests.ReportedIssues/Issue454Tests.cs

diff --git a/src/ExtendedXmlSerializer/ExtensionModel/References/ReferenceEncounters.cs b/src/ExtendedXmlSerializer/ExtensionModel/References/ReferenceEncounters.cs
index b0b37bb97..622543adc 100644
--- a/src/ExtendedXmlSerializer/ExtensionModel/References/ReferenceEncounters.cs
+++ b/src/ExtendedXmlSerializer/ExtensionModel/References/ReferenceEncounters.cs
@@ -1,35 +1,41 @@
-using System.Linq;
-using System.Reflection;
 using ExtendedXmlSerializer.ContentModel.Format;
 using ExtendedXmlSerializer.Core;
 using ExtendedXmlSerializer.Core.Sources;
 using JetBrains.Annotations;
+using System.Linq;
 
 namespace ExtendedXmlSerializer.ExtensionModel.References
 {
 	sealed class ReferenceEncounters : ReferenceCacheBase<IFormatWriter, IEncounters>, IReferenceEncounters
 	{
-		readonly IRootReferences   _references;
-		readonly IEntities         _entities;
-		readonly ObjectIdGenerator _generator;
+		readonly IRootReferences _references;
+		readonly IEntities       _entities;
 
 		[UsedImplicitly]
 		public ReferenceEncounters(IRootReferences references, IEntities entities)
-			: this(references, entities, new ObjectIdGenerator()) {}
-
-		public ReferenceEncounters(IRootReferences references, IEntities entities, ObjectIdGenerator generator)
 		{
 			_references = references;
 			_entities   = entities;
-			_generator  = generator;
 		}
 
 		protected override IEncounters Create(IFormatWriter parameter)
-			=> new Encounters(_references.Get(parameter)
-			                             .ToDictionary(x => x, Get));
+			=> new Encounters(_references.Get(parameter).ToDictionary(x => x, new Generators(_entities).Get));
+
+		sealed class Generators : StructureCacheBase<object, Identifier>
+		{
+			readonly IEntities         _entities;
+			readonly ObjectIdGenerator _generator;
+
+			public Generators(IEntities entities) : this(entities, new ObjectIdGenerator()) {}
 
-		Identifier Get(object parameter)
-			=> new Identifier(_generator.For(parameter), _entities.Get(parameter.GetType()
-			                                                                    .GetTypeInfo()));
+			public Generators(IEntities entities, ObjectIdGenerator generator)
+			{
+				_entities  = entities;
+				_generator = generator;
+			}
+
+			protected override Identifier Create(object parameter)
+				=> new Identifier(_generator.For(parameter), _entities.Get(parameter.GetType()));
+		}
 	}
 }
\ No newline at end of file
diff --git a/test/ExtendedXmlSerializer.Tests.ReportedIssues/Issue454Tests.cs b/test/ExtendedXmlSerializer.Tests.ReportedIssues/Issue454Tests.cs
new file mode 100644
index 000000000..20074b4db
--- /dev/null
+++ b/test/ExtendedXmlSerializer.Tests.ReportedIssues/Issue454Tests.cs
@@ -0,0 +1,38 @@
+using ExtendedXmlSerializer.Configuration;
+using ExtendedXmlSerializer.Tests.ReportedIssues.Support;
+using FluentAssertions;
+using Xunit;
+
+namespace ExtendedXmlSerializer.Tests.ReportedIssues
+{
+	public sealed class Issue454Tests
+	{
+		[Fact]
+		public void Verify()
+		{
+			var serializer = new ConfigurationContainer().UseAutoFormatting()
+			                                             .UseOptimizedNamespaces()
+			                                             .EnableReferences()
+			                                             .Create()
+			                                             .ForTesting();
+
+			var myRef = new Foo();
+			var instance = new Foo
+			{
+				Ref1 = myRef,
+				Ref2 = myRef
+			};
+
+			var first  = serializer.Serialize(serializer.Cycle(instance));
+			var second = serializer.Serialize(serializer.Cycle(instance));
+
+			first.Should().Be(second);
+		}
+
+		public class Foo
+		{
+			public Foo Ref1 { get; set; }
+			public Foo Ref2 { get; set; }
+		}
+	}
+}
\ No newline at end of file