From 0c1e58a55c5a6ea7db0df3e1e08806d34f70886c Mon Sep 17 00:00:00 2001
From: James Newton-King <james@newtonking.com>
Date: Tue, 26 Dec 2023 12:47:52 +0800
Subject: [PATCH] Fix schema generation of sealed type with extension data
 (#332)

---
 .../Issues/Issue0331Tests.cs                  | 45 +++++++++++++++++++
 .../Generation/JSchemaGeneratorInternal.cs    |  2 +-
 2 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 Src/Newtonsoft.Json.Schema.Tests/Issues/Issue0331Tests.cs

diff --git a/Src/Newtonsoft.Json.Schema.Tests/Issues/Issue0331Tests.cs b/Src/Newtonsoft.Json.Schema.Tests/Issues/Issue0331Tests.cs
new file mode 100644
index 00000000..ac3d0f44
--- /dev/null
+++ b/Src/Newtonsoft.Json.Schema.Tests/Issues/Issue0331Tests.cs
@@ -0,0 +1,45 @@
+#region License
+// Copyright (c) Newtonsoft. All Rights Reserved.
+// License: https://raw.github.com/JamesNK/Newtonsoft.Json.Schema/master/LICENSE.md
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using Newtonsoft.Json.Linq;
+using Newtonsoft.Json.Schema.Generation;
+using Newtonsoft.Json.Serialization;
+#if DNXCORE50
+using Xunit;
+using Test = Xunit.FactAttribute;
+using Assert = Newtonsoft.Json.Schema.Tests.XUnitAssert;
+#else
+using NUnit.Framework;
+#endif
+
+namespace Newtonsoft.Json.Schema.Tests.Issues
+{
+    [TestFixture]
+    public class Issue0331Tests : TestFixtureBase
+    {
+        [Test]
+        public void Test()
+        {
+            JSchemaGenerator generator = new JSchemaGenerator();
+            JSchema schema = generator.Generate(typeof(MyDto));
+
+            Assert.IsFalse(schema.AllowAdditionalPropertiesSpecified);
+        }
+
+        public sealed class MyDto
+        {
+            [JsonProperty("foo")]
+            public string Foo { get; set; }
+
+            [JsonExtensionData]
+            public IDictionary<string, JToken> ExtensionData { get; set; }
+        }
+    }
+}
diff --git a/Src/Newtonsoft.Json.Schema/Generation/JSchemaGeneratorInternal.cs b/Src/Newtonsoft.Json.Schema/Generation/JSchemaGeneratorInternal.cs
index f0ca2efa..4a38d924 100644
--- a/Src/Newtonsoft.Json.Schema/Generation/JSchemaGeneratorInternal.cs
+++ b/Src/Newtonsoft.Json.Schema/Generation/JSchemaGeneratorInternal.cs
@@ -642,7 +642,7 @@ private void GenerateObjectSchema(JSchema schema, Type type, JsonObjectContract
                 }
             }
 
-            if (type.IsSealed())
+            if (type.IsSealed() && contract.ExtensionDataGetter == null)
             {
                 schema.AllowAdditionalProperties = false;
             }