Address review: handle process-exit race and check elevation result

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: MuyuanMS

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Commands/EndTaskCommand.cs

@@ -66,6 +66,10 @@ private static bool KillProcess(Window window)
         {
             window.Process.KillThisProcess(SettingsManager.Instance.KillProcessTree);
         }
+        catch (ArgumentException)
+        {
+            // The process already exited between the existence check and the kill attempt.
+        }
         catch (Win32Exception ex)
         {
             ExtensionHost.LogMessage(new LogMessage { Message = $"Failed to kill process '{window.Process.Name}' ({window.Process.ProcessID}) of the window '{window.Title}' ({window.Hwnd}): {ex.Message}" });

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Components/WindowProcess.cs

@@ -2,6 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System;
 using System.ComponentModel;
 using System.Diagnostics;
 using Microsoft.CmdPal.Ext.WindowWalker.Commands;
@@ -220,10 +221,14 @@ internal static string GetProcessNameFromProcessID(uint pid)
     /// <param name="killProcessTree">Kill process and sub processes.</param>
     internal void KillThisProcess(bool killProcessTree)
     {
+        var killTree = killProcessTree ? " /t" : string.Empty;
+
         if (IsFullAccessDenied)
         {
-            var killTree = killProcessTree ? " /t" : string.Empty;
-            ExplorerInfoResultCommand.OpenInShell("taskkill.exe", $"/pid {(int)ProcessID} /f{killTree}", null, ExplorerInfoResultCommand.ShellRunAsType.Administrator, true);
+            if (!ExplorerInfoResultCommand.OpenInShell("taskkill.exe", $"/pid {(int)ProcessID} /f{killTree}", null, ExplorerInfoResultCommand.ShellRunAsType.Administrator, true))
+            {
+                throw new InvalidOperationException($"Failed to start elevated taskkill for process ID {ProcessID}.");
+            }
         }
         else
         {
@@ -236,8 +241,10 @@ internal void KillThisProcess(bool killProcessTree)
             {
                 // Error 5 = ERROR_ACCESS_DENIED
                 // Fall back to elevated taskkill when direct kill is denied
-                var killTree = killProcessTree ? " /t" : string.Empty;
-                ExplorerInfoResultCommand.OpenInShell("taskkill.exe", $"/pid {(int)ProcessID} /f{killTree}", null, ExplorerInfoResultCommand.ShellRunAsType.Administrator, true);
+                if (!ExplorerInfoResultCommand.OpenInShell("taskkill.exe", $"/pid {(int)ProcessID} /f{killTree}", null, ExplorerInfoResultCommand.ShellRunAsType.Administrator, true))
+                {
+                    throw new InvalidOperationException($"Failed to start elevated taskkill for process ID {ProcessID}.", ex);
+                }
             }
         }
     }

src/modules/launcher/Plugins/Microsoft.Plugin.WindowWalker/Components/ContextMenuHelper.cs

@@ -107,6 +107,10 @@ private static bool KillProcessCommand(Window window)
             {
                 window.Process.KillThisProcess(WindowWalkerSettings.Instance.KillProcessTree);
             }
+            catch (ArgumentException)
+            {
+                // The process already exited between the existence check and the kill attempt.
+            }
             catch (Win32Exception ex)
             {
                 Log.Exception($"Failed to kill process '{window.Process.Name}' ({window.Process.ProcessID}) of the window '{window.Title}' ({window.Hwnd}).", ex, typeof(ContextMenuHelper));

src/modules/launcher/Plugins/Microsoft.Plugin.WindowWalker/Components/WindowProcess.cs

@@ -209,10 +209,14 @@ internal static string GetProcessNameFromProcessID(uint pid)
         /// <param name="killProcessTree">Kill process and sub processes.</param>
         internal void KillThisProcess(bool killProcessTree)
         {
+            string killTree = killProcessTree ? " /t" : string.Empty;
+
             if (IsFullAccessDenied)
             {
-                string killTree = killProcessTree ? " /t" : string.Empty;
-                Helper.OpenInShell("taskkill.exe", $"/pid {(int)ProcessID} /f{killTree}", null, Helper.ShellRunAsType.Administrator, true);
+                if (!Helper.OpenInShell("taskkill.exe", $"/pid {(int)ProcessID} /f{killTree}", null, Helper.ShellRunAsType.Administrator, true))
+                {
+                    throw new InvalidOperationException($"Failed to start elevated taskkill for process ID {ProcessID}.");
+                }
             }
             else
             {
@@ -225,8 +229,10 @@ internal void KillThisProcess(bool killProcessTree)
                 {
                     // Error 5 = ERROR_ACCESS_DENIED
                     // Fall back to elevated taskkill when direct kill is denied
-                    string killTree = killProcessTree ? " /t" : string.Empty;
-                    Helper.OpenInShell("taskkill.exe", $"/pid {(int)ProcessID} /f{killTree}", null, Helper.ShellRunAsType.Administrator, true);
+                    if (!Helper.OpenInShell("taskkill.exe", $"/pid {(int)ProcessID} /f{killTree}", null, Helper.ShellRunAsType.Administrator, true))
+                    {
+                        throw new InvalidOperationException($"Failed to start elevated taskkill for process ID {ProcessID}.", ex);
+                    }
                 }
             }
         }