From 506869c157fbd481a3f6f9f9e50d9d0efec1fede Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Mon, 22 Sep 2025 21:19:39 -0700
Subject: [PATCH] Fix `-Debug` to not trigger the `ShouldProcess` prompt
 (#26081)

---
 .../engine/MshCommandRuntime.cs               | 12 +++---
 .../Write-Debug.Tests.ps1                     | 40 +++++++++++++++++++
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/src/System.Management.Automation/engine/MshCommandRuntime.cs b/src/System.Management.Automation/engine/MshCommandRuntime.cs
index 883c800dea..2e5cdb455b 100644
--- a/src/System.Management.Automation/engine/MshCommandRuntime.cs
+++ b/src/System.Management.Automation/engine/MshCommandRuntime.cs
@@ -2992,21 +2992,19 @@ namespace System.Management.Automation
             {
                 // WhatIf not relevant, it never gets this far in that case
                 if (Confirm)
-                    return ConfirmImpact.Low;
-                if (Debug)
                 {
-                    if (IsConfirmFlagSet) // -Debug -Confirm:$false
-                        return ConfirmImpact.None;
                     return ConfirmImpact.Low;
                 }
 
-                if (IsConfirmFlagSet) // -Confirm:$false
+                if (IsConfirmFlagSet)
+                {
+                    // -Confirm:$false
                     return ConfirmImpact.None;
+                }
 
                 if (!_isConfirmPreferenceCached)
                 {
-                    bool defaultUsed = false;
-                    _confirmPreference = Context.GetEnumPreference(SpecialVariables.ConfirmPreferenceVarPath, _confirmPreference, out defaultUsed);
+                    _confirmPreference = Context.GetEnumPreference(SpecialVariables.ConfirmPreferenceVarPath, _confirmPreference, out _);
                     _isConfirmPreferenceCached = true;
                 }
 
diff --git a/test/powershell/Modules/Microsoft.PowerShell.Utility/Write-Debug.Tests.ps1 b/test/powershell/Modules/Microsoft.PowerShell.Utility/Write-Debug.Tests.ps1
index f93027cc57..951400349c 100644
--- a/test/powershell/Modules/Microsoft.PowerShell.Utility/Write-Debug.Tests.ps1
+++ b/test/powershell/Modules/Microsoft.PowerShell.Utility/Write-Debug.Tests.ps1
@@ -34,4 +34,44 @@ Describe "Write-Debug tests" -Tags "CI" {
         $out = $p.StandardError.ReadToEnd()
         $out | Should -BeNullOrEmpty
     }
+
+    It "'-Debug' should not trigger 'ShouldProcess'" {
+        $pwsh = [PowerShell]::Create()
+        $pwsh.AddScript(@'
+function Test-DebugWithConfirm
+{
+    [CmdletBinding(SupportsShouldProcess = $true, ConfirmImpact = 'Low')]
+    Param ()
+
+    PROCESS
+    {
+        Write-Debug -Message "Debug_Message1"
+        If ($PSCmdlet.ShouldProcess('Doing the thing.','Proceed?','Ready to do the thing.'))
+        {
+            Write-Output 'success'
+        }
+        Write-Debug -Message "Debug_Message2"
+    }
+
+    END {}
+}
+'@)
+        $pwsh.Invoke()
+        $pwsh.Commands.Clear()
+        $pwsh.Streams.ClearStreams()
+
+        try {
+            $result = $pwsh.AddScript("Test-DebugWithConfirm -Debug").Invoke()
+            $result.Count | Should -BeExactly 1
+            $result[0] | Should -BeExactly 'success'
+
+            $pwsh.Streams.Error.Count | Should -BeExactly 0
+            $pwsh.Streams.Debug.Count | Should -BeExactly 2
+            $pwsh.Streams.Debug[0] | Should -BeExactly 'Debug_Message1'
+            $pwsh.Streams.Debug[1] | Should -BeExactly 'Debug_Message2'
+        }
+        finally {
+            $pwsh.Dispose()
+        }
+    }
 }