Fix URI deserialization

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/MrwSerializationTypeDefinition.Xml.cs

@@ -1023,7 +1023,7 @@ private static ValueExpression CreateXmlDeserializePrimitiveExpression(
         {
             return valueType.FrameworkType switch
             {
-                Type t when t == typeof(Uri) => New.Instance(valueType.FrameworkType, element.Value()),
+                Type t when t == typeof(Uri) => New.Instance<Uri>(element.Value(), FrameworkEnumValue(UriKind.RelativeOrAbsolute)),
                 Type t when t == typeof(IPAddress) => Static<IPAddress>().Invoke(nameof(IPAddress.Parse), element.Value()),
                 Type t when t == typeof(Stream) => BinaryDataSnippets.FromString(element.Value()).ToStream(),
                 Type t when t == typeof(byte[]) => element.GetBytesFromBase64(serializationFormat.ToFormatSpecifier()),

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/MrwSerializationTypeDefinition.cs

@@ -2226,7 +2226,7 @@ internal static ValueExpression DeserializeJsonValueCore(
             ValueExpression? exp = frameworkType switch
             {
                 Type t when t == typeof(Uri) =>
-                    New.Instance(frameworkType, element.GetString()),
+                    New.Instance<Uri>(element.GetString(), FrameworkEnumValue(UriKind.RelativeOrAbsolute)),
                 Type t when t == typeof(IPAddress) =>
                     Static<IPAddress>().Invoke(nameof(IPAddress.Parse), element.GetString()),
                 Type t when t == typeof(BinaryData) =>

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/MrwSerializationTypeDefinitions/DeserializationTests.cs

@@ -93,5 +93,25 @@ public static IEnumerable<TestCaseData> TestDeserializationStatementTestCases
                     false);
             }
         }
+
+        [Test]
+        public void TestDeserializationUsesUriKindRelativeOrAbsolute()
+        {
+            var inputModel = InputFactory.Model("TestModel", properties:
+                [InputFactory.Property("prop1", InputPrimitiveType.Url)]);
+
+            var mrwProvider = new ModelProvider(inputModel).SerializationProviders.FirstOrDefault();
+            Assert.IsNotNull(mrwProvider);
+
+            var deserializationMethod = mrwProvider!.Methods.Where(m => m.Signature.Name.StartsWith("Deserialize")).FirstOrDefault();
+            Assert.IsNotNull(deserializationMethod);
+
+            var methodBody = deserializationMethod!.BodyStatements!.ToDisplayString();
+
+            Assert.IsTrue(methodBody.Contains("new global::System.Uri("),
+                $"Uri property should use new Uri() constructor. Actual:\n{methodBody}");
+            Assert.IsTrue(methodBody.Contains("global::System.UriKind.RelativeOrAbsolute"),
+                $"Uri property should specify UriKind.RelativeOrAbsolute. Actual:\n{methodBody}");
+        }
     }
 }

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/MrwSerializationTypeDefinitions/TestData/ModelCustomizationTests/CanCustomizeUriProperty.cs

@@ -110,7 +110,7 @@ protected virtual void JsonModelWriteCore(global::System.Text.Json.Utf8JsonWrite
                     {
                         continue;
                     }
-                    prop1 = string.IsNullOrEmpty(prop.Value.GetString()) ? null : new global::System.Uri(prop.Value.GetString());
+                    prop1 = string.IsNullOrEmpty(prop.Value.GetString()) ? null : new global::System.Uri(prop.Value.GetString(), global::System.UriKind.RelativeOrAbsolute);
                     continue;
                 }
                 if ((options.Format != "W"))

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/MrwSerializationTypeDefinitions/XmlDeserializationTests.cs

@@ -239,6 +239,32 @@ public void XmlDeserializationHandlesBytesProperty()
                 $"Bytes property should use child.GetBytesFromBase64(\"D\") with Base64 format. Actual:\n{methodBody}");
         }
 
+        [Test]
+        public void XmlDeserializationHandlesUriProperty()
+        {
+            var inputModel = InputFactory.Model(
+                "TestXmlModel",
+                usage: InputModelTypeUsage.Input | InputModelTypeUsage.Xml,
+                properties: [InputFactory.Property(
+                    "endpoint",
+                    InputPrimitiveType.Url,
+                    serializationOptions: InputFactory.Serialization.Options(xml: InputFactory.Serialization.Xml("endpoint")))]);
+
+            var modelProvider = new ModelProvider(inputModel);
+            var mrwProvider = modelProvider.SerializationProviders.FirstOrDefault() as MrwSerializationTypeDefinition;
+            Assert.IsNotNull(mrwProvider);
+            var xmlDeserializationMethod = mrwProvider!.Methods.FirstOrDefault(m => m.Signature.Name == "DeserializeTestXmlModel" &&
+                m.Signature.Parameters.Any(p => p.Type.Equals(typeof(XElement))));
+
+            Assert.IsNotNull(xmlDeserializationMethod);
+            var methodBody = xmlDeserializationMethod!.BodyStatements!.ToDisplayString();
+
+            Assert.IsTrue(methodBody.Contains("new global::System.Uri("),
+                $"Uri property should use new Uri() constructor for deserialization. Actual:\n{methodBody}");
+            Assert.IsTrue(methodBody.Contains("global::System.UriKind.RelativeOrAbsolute"),
+                $"Uri property should specify UriKind.RelativeOrAbsolute. Actual:\n{methodBody}");
+        }
+
         [Test]
         public void XmlDeserializationHandlesBinaryDataProperty()
         {

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/ScalarReturnTypeMethods(Uri).cs

@@ -2,4 +2,4 @@
 global::System.BinaryData data = result.GetRawResponse().Content;
 using global::System.Text.Json.JsonDocument document = global::System.Text.Json.JsonDocument.Parse(data);
 global::System.Text.Json.JsonElement element = document.RootElement;
-return global::System.ClientModel.ClientResult.FromValue(new global::System.Uri(element.GetString()), result.GetRawResponse());
+return global::System.ClientModel.ClientResult.FromValue(new global::System.Uri(element.GetString(), global::System.UriKind.RelativeOrAbsolute), result.GetRawResponse());

packages/http-client-csharp/generator/TestProjects/Local/Sample-TypeSpec/src/Generated/Models/ListWithNextLinkResponse.Serialization.cs

@@ -162,7 +162,7 @@ internal static ListWithNextLinkResponse DeserializeListWithNextLinkResponse(Jso
                     {
                         continue;
                     }
-                    next = string.IsNullOrEmpty(prop.Value.GetString()) ? null : new Uri(prop.Value.GetString());
+                    next = string.IsNullOrEmpty(prop.Value.GetString()) ? null : new Uri(prop.Value.GetString(), UriKind.RelativeOrAbsolute);
                     continue;
                 }
                 if (options.Format != "W")