From a28432ac28574611ba442a9200cb6741ce6ee96b Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 27 Sep 2025 13:59:39 +0000
Subject: [PATCH 1/2] Initial plan


From a1a32e02cc0c70296762e1237ec78e398f4fa529 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 27 Sep 2025 14:11:24 +0000
Subject: [PATCH 2/2] Add System.Uri::EscapeDataString to MSBuild property
 function allowlist

Co-authored-by: baronfel <573979+baronfel@users.noreply.github.com>
---
 .../IntrinsicFunctionOverload_Tests.cs        | 22 +++++++++++++++++++
 src/Build/Resources/Constants.cs              |  1 +
 2 files changed, 23 insertions(+)

diff --git a/src/Build.UnitTests/Evaluation/IntrinsicFunctionOverload_Tests.cs b/src/Build.UnitTests/Evaluation/IntrinsicFunctionOverload_Tests.cs
index 8f162834b18..405aa0436af 100644
--- a/src/Build.UnitTests/Evaluation/IntrinsicFunctionOverload_Tests.cs
+++ b/src/Build.UnitTests/Evaluation/IntrinsicFunctionOverload_Tests.cs
@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.IO;
 using Microsoft.Build.Evaluation;
 using Microsoft.Build.Framework;
@@ -568,5 +569,26 @@ public void MSBuildModuloReal()
             ProjectProperty? actualProperty = project.GetProperty("Actual");
             actualProperty.EvaluatedValue.ShouldBe(expected);
         }
+
+        [Fact]
+        public void SystemUriEscapeDataString()
+        {
+            const string projectContent = @"
+                    <Project>
+                        <PropertyGroup>
+                            <TestInput>hello world &amp; friends</TestInput>
+                            <Escaped>$([System.Uri]::EscapeDataString($(TestInput)))</Escaped>
+                        </PropertyGroup>
+                    </Project>";
+
+            string expected = Uri.EscapeDataString("hello world & friends");
+
+            using TestEnvironment env = TestEnvironment.Create();
+
+            using ProjectFromString projectFromString = new(projectContent.Cleanup());
+            Project project = projectFromString.Project;
+            ProjectProperty? actualProperty = project.GetProperty("Escaped");
+            actualProperty.EvaluatedValue.ShouldBe(expected);
+        }
     }
 }
diff --git a/src/Build/Resources/Constants.cs b/src/Build/Resources/Constants.cs
index 7c848594fba..7d439a637c1 100644
--- a/src/Build/Resources/Constants.cs
+++ b/src/Build/Resources/Constants.cs
@@ -394,6 +394,7 @@ private static void InitializeAvailableMethods()
                         availableStaticMethods.TryAdd("System.StringComparer", new Tuple<string, Type>(null, typeof(StringComparer)));
                         availableStaticMethods.TryAdd("System.TimeSpan", new Tuple<string, Type>(null, typeof(TimeSpan)));
                         availableStaticMethods.TryAdd("System.Text.RegularExpressions.Regex", new Tuple<string, Type>(null, typeof(Regex)));
+                        availableStaticMethods.TryAdd("System.Uri", new Tuple<string, Type>(null, typeof(Uri)));
                         availableStaticMethods.TryAdd("System.UriBuilder", new Tuple<string, Type>(null, typeof(UriBuilder)));
                         availableStaticMethods.TryAdd("System.Version", new Tuple<string, Type>(null, typeof(Version)));
                         availableStaticMethods.TryAdd("Microsoft.Build.Utilities.ToolLocationHelper", new Tuple<string, Type>("Microsoft.Build.Utilities.ToolLocationHelper, Microsoft.Build.Utilities.Core, Version=" + MSBuildConstants.CurrentAssemblyVersion + ", Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", null));