ui: extend console parenting beyond MSAL

docs/environment.md

@@ -177,6 +177,12 @@ Defaults to enabled.
 
 Specify the parent window handle (`HWND`) for modal dialogs on Windows.
 
+When this variable is unset, GCM tries to parent authentication dialogs to the
+console's visible root-owner window. Hidden or invalid windows are ignored.
+
+Explicitly setting a handle using this variable takes precedence and it is not
+checked for visibility.
+
 > [!NOTE]
 > This is intended for use by application developers who are calling Git and/or
 > GCM from their application and wish to correctly parent authentication dialogs

src/Core.Tests/Authentication/Entra/MsalParentWindowAdapterTests.cs

@@ -10,60 +10,22 @@ public class MsalParentWindowAdapterTests
     [Theory]
     [InlineData(42, false)]
     [InlineData(42, true)]
-    [InlineData(-1, false)]
-    [InlineData(-1, true)]
-    public void GetWindow_ExplicitParent_TakesPrecedence(int parentValue, bool createIfMissing)
+    public void GetWindow_ExplicitParent_ReturnsParent(int parentValue, bool createIfMissing)
     {
         object parentWindow = new IntPtr(parentValue);
         using var adapter = new MsalParentWindowAdapter(parentWindow, createIfMissing,
-            () => throw new InvalidOperationException("Console lookup should not be called."),
-            _ => throw new InvalidOperationException("Visibility should not be checked."),
             _ => throw new InvalidOperationException("A progress window should not be created."));
 
         object result = adapter.GetWindow();
         Assert.Same(parentWindow, result);
     }
 
-    [Theory]
-    [InlineData(false)]
-    [InlineData(true)]
-    public void GetWindow_VisibleConsoleRoot_PrecedesProgressWindow(bool createIfMissing)
-    {
-        var consoleRoot = new IntPtr(42);
-        bool visibilityChecked = false;
-        using var adapter = new MsalParentWindowAdapter(IntPtr.Zero, createIfMissing,
-            () => consoleRoot,
-            hwnd =>
-            {
-                Assert.Equal(consoleRoot, hwnd);
-                visibilityChecked = true;
-                return true;
-            },
-            _ => throw new InvalidOperationException("A progress window should not be created."));
-
-        IntPtr result = Assert.IsType<IntPtr>(adapter.GetWindow());
-
-        Assert.Equal(consoleRoot, result);
-        Assert.True(visibilityChecked);
-    }
-
-    [Theory]
-    [InlineData(0)]
-    [InlineData(42)]
-    public void GetWindow_NoVisibleConsoleRoot_CreatesProgressWhenRequired(int consoleRootValue)
+    [Fact]
+    public void GetWindow_NoParent_Required_CreatesProgressWindow()
     {
-        var consoleRoot = new IntPtr(consoleRootValue);
-        var progressWindow = new IntPtr(84);
-        int visibilityChecks = 0;
+        var progressWindow = new IntPtr(42);
         var windowToken = CancellationToken.None;
         using (var adapter = new MsalParentWindowAdapter(IntPtr.Zero, true,
-            () => consoleRoot,
-            hwnd =>
-            {
-                Assert.Equal(consoleRoot, hwnd);
-                visibilityChecks++;
-                return false;
-            },
             ct =>
             {
                 windowToken = ct;
@@ -73,66 +35,21 @@ public void GetWindow_NoVisibleConsoleRoot_CreatesProgressWhenRequired(int conso
             IntPtr result = Assert.IsType<IntPtr>(adapter.GetWindow());
 
             Assert.Equal(progressWindow, result);
-            Assert.Equal(consoleRootValue == 0 ? 0 : 1, visibilityChecks);
             Assert.True(windowToken.CanBeCanceled);
             Assert.False(windowToken.IsCancellationRequested);
         }
 
         Assert.True(windowToken.IsCancellationRequested);
     }
 
-    [Theory]
-    [InlineData(0)]
-    [InlineData(42)]
-    public void GetWindow_NoVisibleConsoleRoot_ReturnsNullWhenParentNotRequired(int consoleRootValue)
-    {
-        var consoleRoot = new IntPtr(consoleRootValue);
-        int visibilityChecks = 0;
-        using var adapter = new MsalParentWindowAdapter(IntPtr.Zero, false,
-            () => consoleRoot,
-            hwnd =>
-            {
-                Assert.Equal(consoleRoot, hwnd);
-                visibilityChecks++;
-                return false;
-            },
-            _ => throw new InvalidOperationException("A progress window should not be created."));
-
-        object result = adapter.GetWindow();
-
-        Assert.Null(result);
-        Assert.Equal(consoleRootValue == 0 ? 0 : 1, visibilityChecks);
-    }
-
     [Fact]
-    public void GetWindow_VisibilityCheckThrows_PropagatesException()
+    public void GetWindow_NoParent_NotRequired_ReturnsNull()
     {
-        var exception = new InvalidOperationException("Visibility check failed.");
-        using var adapter = new MsalParentWindowAdapter(IntPtr.Zero, true,
-            () => new IntPtr(42),
-            _ => throw exception,
+        using var adapter = new MsalParentWindowAdapter(IntPtr.Zero, false,
             _ => throw new InvalidOperationException("A progress window should not be created."));
 
-        var thrown = Assert.Throws<InvalidOperationException>(adapter.GetWindow);
-        Assert.Same(exception, thrown);
-    }
-
-    [Fact]
-    public void Create_ExplicitParent_IsReturned()
-    {
-        object parentWindow = new IntPtr(42);
-        using var adapter = MsalParentWindowAdapter.Create(parentWindow, true);
-
         object result = adapter.GetWindow();
-        Assert.Same(parentWindow, result);
-    }
-
-    [PosixFact]
-    public void Create_NoExplicitParent_Posix_ReturnsNull()
-    {
-        using var adapter = MsalParentWindowAdapter.Create(IntPtr.Zero);
 
-        object result = adapter.GetWindow();
         Assert.Null(result);
     }
 }

src/Core/Authentication/AuthenticationBase.cs

@@ -5,7 +5,6 @@
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
-using GitCredentialManager.Tty;
 using GitCredentialManager.UI.ViewModels;
 
 namespace GitCredentialManager.Authentication
@@ -125,11 +124,19 @@ protected void ThrowIfWindowCancelled(WindowViewModel viewModel)
 
         protected IntPtr GetParentWindowHandle()
         {
+            // Check if the user has specified a parent window ID
             if (int.TryParse(Context.Settings.ParentWindowId, out int id))
             {
                 return new IntPtr(id);
             }
 
+            // Check if we can use the console window as a parent
+            IntPtr consoleParent = PlatformUtils.GetConsoleParentWindow();
+            if (consoleParent != IntPtr.Zero)
+            {
+                return consoleParent;
+            }
+
             return IntPtr.Zero;
         }
 

src/Core/Authentication/Entra/MsalAdaptors.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Net.Http;
 using System.Threading;
-using GitCredentialManager.Interop.Windows.Native;
 using GitCredentialManager.UI.Controls;
 using Microsoft.Identity.Client;
 
@@ -31,48 +30,32 @@ internal class MsalParentWindowAdapter : IDisposable
     private readonly bool _createIfMissing;
     private readonly CancellationTokenSource _cts = new();
 
-    private readonly Func<IntPtr> _getConsoleParentWindow;
-    private readonly Func<IntPtr, bool> _isWindowVisible;
     private readonly Func<CancellationToken, IntPtr> _createWindow;
 
     public static MsalParentWindowAdapter Create(object parentWindow, bool createIfMissing = false)
     {
-        return new MsalParentWindowAdapter(parentWindow, createIfMissing,
-            GetConsoleParentWindow, User32.IsWindowVisible, ProgressWindow.ShowAndGetHandle);
+        return new MsalParentWindowAdapter(parentWindow, createIfMissing, ProgressWindow.ShowAndGetHandle);
     }
 
     internal MsalParentWindowAdapter(object parentWindow, bool createIfMissing,
-        Func<IntPtr> getConsoleParentWindow, Func<IntPtr, bool> isWindowVisible,
         Func<CancellationToken, IntPtr> createWindow)
     {
-        EnsureArgument.NotNull(getConsoleParentWindow, nameof(getConsoleParentWindow));
-        EnsureArgument.NotNull(isWindowVisible, nameof(isWindowVisible));
         EnsureArgument.NotNull(createWindow, nameof(createWindow));
 
         _parentWindow = parentWindow;
         _createIfMissing = createIfMissing;
-
-        _getConsoleParentWindow = getConsoleParentWindow;
-        _isWindowVisible = isWindowVisible;
         _createWindow = createWindow;
     }
 
     public object GetWindow()
     {
+        // Try to use the parent window we were given (if any)
         if (_parentWindow is IntPtr p && p != IntPtr.Zero)
         {
             return _parentWindow;
         }
 
-        // See if we can use the console window as a parent.
-        // We only consider the window if it is valid and visible.
-        IntPtr consoleParent = _getConsoleParentWindow();
-        if (consoleParent != IntPtr.Zero && _isWindowVisible(consoleParent))
-        {
-            return consoleParent;
-        }
-
-        // Create a stub window to use as a parent
+        // Create a stub window to use as a parent instead (if the caller requires it)
         if (_createIfMissing)
         {
             return _createWindow(_cts.Token);
@@ -81,23 +64,6 @@ public object GetWindow()
         return null;
     }
 
-    private static IntPtr GetConsoleParentWindow()
-    {
-        // On Windows we can try and get the console window parent handle if that exists
-        if (!PlatformUtils.IsWindows())
-        {
-            return IntPtr.Zero;
-        }
-
-        IntPtr consoleHandle = Kernel32.GetConsoleWindow();
-
-        // When the parent is using ConPTY (pseudo-terminals) the console
-        // window may be a fake/stub (as is the case with Windows Terminal).
-        // This means we need to walk up the ancestor chain to get the actual
-        // root owner (typically the terminal emulator's window).
-        return User32.GetAncestor(consoleHandle, GetAncestorFlags.GetRootOwner);
-    }
-
     public void Dispose()
     {
         // Close and clean up any stub window we may have created

src/Core/PlatformUtils.cs

@@ -5,6 +5,7 @@
 using System.Runtime.InteropServices;
 using System.Runtime.Versioning;
 using GitCredentialManager.Interop.Posix.Native;
+using GitCredentialManager.Interop.Windows.Native;
 
 namespace GitCredentialManager
 {
@@ -211,6 +212,36 @@ public static bool IsElevatedUser()
             return false;
         }
 
+        public static IntPtr GetConsoleParentWindow()
+        {
+            // On Windows we can try and get the console window parent handle if that exists
+            if (!IsWindows())
+            {
+                return IntPtr.Zero;
+            }
+
+            IntPtr consoleHandle = Kernel32.GetConsoleWindow();
+
+            // When the parent is using ConPTY (pseudo-terminals) the console
+            // window may be a fake/stub (as is the case with Windows Terminal).
+            // This means we need to walk up the ancestor chain to get the actual
+            // root owner (typically the terminal emulator's window).
+            IntPtr parent = User32.GetAncestor(consoleHandle, GetAncestorFlags.GetRootOwner);
+
+            // On Windows the parent window may be hidden (not visible) if the console is
+            // running in a background process (like a service).
+            // We do not consider a hidden window as a valid parent. We do however consider
+            // a minimised window as a valid parent (and the user is able to restore it and
+            // see our child window too).
+            if (User32.IsWindowVisible(parent))
+            {
+                return parent;
+            }
+
+            // No visible console window available!
+            return IntPtr.Zero;
+        }
+
         #region Platform Entry Path Utils
 
         /// <summary>

src/Core/UI/HelperCommand.cs

@@ -16,11 +16,19 @@ public HelperCommand(ICommandContext context, string name, string description)
 
         protected IntPtr GetParentHandle()
         {
+            // Check if the user has specified a parent window ID
             if (int.TryParse(Context.Settings.ParentWindowId, out int id))
             {
                 return new IntPtr(id);
             }
 
+            // Check if we can use the console window as a parent
+            IntPtr consoleParent = PlatformUtils.GetConsoleParentWindow();
+            if (consoleParent != IntPtr.Zero)
+            {
+                return consoleParent;
+            }
+
             return IntPtr.Zero;
         }