From c00290ffcce4e177ae7097dad54bd9656e004ab7 Mon Sep 17 00:00:00 2001
From: Tig <tig@users.noreply.github.com>
Date: Sat, 17 Aug 2024 09:22:52 -0600
Subject: [PATCH] Added unit test & fixed bug (#3666)

---
 Terminal.Gui/Views/Shortcut.cs   |  2 ++
 UnitTests/Views/ShortcutTests.cs | 46 +++++++++++++++++++++-----------
 2 files changed, 32 insertions(+), 16 deletions(-)

diff --git a/Terminal.Gui/Views/Shortcut.cs b/Terminal.Gui/Views/Shortcut.cs
index 6530d71bc..0ce5da072 100644
--- a/Terminal.Gui/Views/Shortcut.cs
+++ b/Terminal.Gui/Views/Shortcut.cs
@@ -806,6 +806,8 @@ public class Shortcut : View, IOrientation, IDesignable
 
         if (HasFocus)
         {
+            base.ColorScheme ??= new (Attribute.Default);
+
             // When we have focus, we invert the colors
             base.ColorScheme = new (base.ColorScheme)
             {
diff --git a/UnitTests/Views/ShortcutTests.cs b/UnitTests/Views/ShortcutTests.cs
index e46e7f199..e2e9afbc7 100644
--- a/UnitTests/Views/ShortcutTests.cs
+++ b/UnitTests/Views/ShortcutTests.cs
@@ -38,9 +38,6 @@ public class ShortcutTests
 
         Assert.IsType<DimAuto> (shortcut.Width);
         Assert.IsType<DimAuto> (shortcut.Height);
-        //shortcut.BeginInit();
-        //shortcut.EndInit ();
-       // shortcut.LayoutSubviews ();
         shortcut.SetRelativeLayout (new (100, 100));
 
         // |0123456789
@@ -256,19 +253,6 @@ public class ShortcutTests
         Assert.True (actionInvoked);
     }
 
-    [Fact]
-    public void ColorScheme_SetsAndGetsCorrectly ()
-    {
-        var colorScheme = new ColorScheme ();
-
-        var shortcut = new Shortcut
-        {
-            ColorScheme = colorScheme
-        };
-
-        Assert.Same (colorScheme, shortcut.ColorScheme);
-    }
-
     [Fact]
     public void Subview_Visibility_Controlled_By_Removal ()
     {
@@ -600,5 +584,35 @@ public class ShortcutTests
     }
 
 
+    [Fact]
+    public void ColorScheme_SetsAndGetsCorrectly ()
+    {
+        var colorScheme = new ColorScheme ();
+
+        var shortcut = new Shortcut
+        {
+            ColorScheme = colorScheme
+        };
+
+        Assert.Same (colorScheme, shortcut.ColorScheme);
+    }
+
+    // https://github.com/gui-cs/Terminal.Gui/issues/3664
+    [Fact]
+    public void ColorScheme_SetColorScheme_Does_Not_Fault_3664 ()
+    {
+        Application.Current = new Toplevel ();
+        Shortcut shortcut = new Shortcut ();
+
+        Application.Current.ColorScheme = null;
+
+        Assert.Null (shortcut.ColorScheme);
+
+        shortcut.HasFocus = true;
+
+        Assert.NotNull (shortcut.ColorScheme);
+
+        Application.Current.Dispose ();
+    }
 
 }