From 959b49a106bdf3dab8d74a843772d271a4036213 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 8 Apr 2026 21:07:18 +0000
Subject: [PATCH 1/2] Initial plan


From 4df6da8ee53f8ece08d0dbc5f70758588e5b4eb6 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 8 Apr 2026 21:15:27 +0000
Subject: [PATCH 2/2] Disable WindowsAlternateDataStreamOverwrite test on
 Windows Arm64

Fixes #83659 - The test intermittently fails with ERROR_INVALID_PARAMETER
on Windows Arm64. Scoped the ActiveIssue to Windows + Arm64 only via
PlatformDetection so it continues to run on all other platforms.

Agent-Logs-Url: https://github.com/dotnet/runtime/sessions/9d0cf153-dc1b-42f2-8909-9441b08bf6d7

Co-authored-by: danmoseley <6385855+danmoseley@users.noreply.github.com>
---
 .../System.Runtime/tests/System.IO.FileSystem.Tests/File/Copy.cs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/File/Copy.cs b/src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/File/Copy.cs
index 99fd855ded6284..a3a8c7526bd045 100644
--- a/src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/File/Copy.cs
+++ b/src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/File/Copy.cs
@@ -361,6 +361,7 @@ public void OverwriteFalse()
             InlineData("::$DATA", ":bar"),
             InlineData("::$DATA", ":bar:$DATA")]
         [PlatformSpecific(TestPlatforms.Windows)]
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/83659", typeof(PlatformDetection), nameof(PlatformDetection.IsWindows), nameof(PlatformDetection.IsArm64Process))]
         public void WindowsAlternateDataStreamOverwrite(string defaultStream, string alternateStream)
         {
             DirectoryInfo testDirectory = Directory.CreateDirectory(GetTestFilePath());