From 1cdbf46c9ecabe5d2cbb5197cacc01c3cd1179f2 Mon Sep 17 00:00:00 2001
From: Andy Jordan <2226434+andyleejordan@users.noreply.github.com>
Date: Thu, 28 Aug 2025 14:21:42 -0700
Subject: [PATCH] Fix `IsMutexPresent()` to avoid incorrect use of
 `GetLastWin32Error()` (#4910)

---
 PSReadLine/PlatformWindows.cs | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/PSReadLine/PlatformWindows.cs b/PSReadLine/PlatformWindows.cs
index 32cf653..2bf72eb 100644
--- a/PSReadLine/PlatformWindows.cs
+++ b/PSReadLine/PlatformWindows.cs
@@ -8,6 +8,7 @@ using System.ComponentModel;
 using System.Diagnostics;
 using System.Linq;
 using System.Runtime.InteropServices;
+using System.Threading;
 using Microsoft.PowerShell;
 using Microsoft.PowerShell.Internal;
 using Microsoft.Win32.SafeHandles;
@@ -79,19 +80,18 @@ static class PlatformWindows
     [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
     internal static extern IntPtr GetStdHandle(uint handleId);
 
-    internal const int ERROR_ALREADY_EXISTS = 0xB7;
-
     internal static bool IsMutexPresent(string name)
     {
         try
         {
-            using var mutex = new System.Threading.Mutex(false, name);
-            return Marshal.GetLastWin32Error() == ERROR_ALREADY_EXISTS;
-        }
-        catch
-        {
-            return false;
+            if (Mutex.TryOpenExisting(name, out var tempMutex))
+            {
+                tempMutex.Dispose();
+                return true;
+            }
         }
+        catch { }
+        return false;
     }
 
     [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]