From 6b90c5c886bb97921e399bdad0279a748d60b596 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@users.noreply.github.com>
Date: Thu, 5 Dec 2024 13:51:02 +0100
Subject: [PATCH] Add failing tests for #17699.

---
 .../Primitives/UniformGridTests.cs            | 71 +++++++++++++++++++
 tests/Avalonia.UnitTests/TestRoot.cs          |  2 +-
 2 files changed, 72 insertions(+), 1 deletion(-)

diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/UniformGridTests.cs b/tests/Avalonia.Controls.UnitTests/Primitives/UniformGridTests.cs
index 340bd09611e..cbfdad43832 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/UniformGridTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/UniformGridTests.cs
@@ -1,4 +1,5 @@
 using Avalonia.Controls.Primitives;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
@@ -140,5 +141,75 @@ public void Not_Visible_Children_Are_Ignored()
             // 2 * 2 grid
             Assert.Equal(new Size(2 * 50, 2 * 70), target.Bounds.Size);
         }
+
+        [Fact]
+        public void Children_Do_Not_Overlap_With_125_Percent_Scaling_1()
+        {
+            // Issue #17699
+            var target = new UniformGrid
+            {
+                Columns = 2,
+                Children =
+                {
+                    new Border(),
+                    new Border(),
+                    new Border(),
+                    new Border(),
+                }
+            };
+
+            var root = new TestRoot
+            {
+                LayoutScaling = 1.25,
+                Child = new Border
+                {
+                    Width = 100,
+                    Height = 100,
+                    Child = target,
+                }
+            };
+
+            root.ExecuteInitialLayoutPass();
+
+            Assert.Equal(new(0, 0, 50.4, 50.4), target.Children[0].Bounds);
+            Assert.Equal(new(50.4, 0, 49.6, 50.4), target.Children[1].Bounds);
+            Assert.Equal(new(0, 50.4, 50.4, 49.6), target.Children[2].Bounds);
+            Assert.Equal(new(50.4, 50.4, 49.6, 49.6), target.Children[3].Bounds);
+        }
+
+        [Fact]
+        public void Children_Do_Not_Overlap_With_125_Percent_Scaling_2()
+        {
+            // Issue #17699
+            var target = new UniformGrid
+            {
+                Columns = 4,
+                Children =
+                {
+                    new Border(),
+                    new Border(),
+                    new Border(),
+                    new Border(),
+                }
+            };
+
+            var root = new TestRoot
+            {
+                LayoutScaling = 1.25,
+                Child = new Border
+                {
+                    Width = 100,
+                    Height = 100,
+                    Child = target,
+                }
+            };
+
+            root.ExecuteInitialLayoutPass();
+
+            Assert.Equal(new(0, 0, 25.6, 100), target.Children[0].Bounds);
+            Assert.Equal(new(25.6, 0, 24.8, 100), target.Children[1].Bounds);
+            Assert.Equal(new(50.4, 0, 24.8, 100), target.Children[2].Bounds);
+            Assert.Equal(new(75.2, 0, 24.8, 100), target.Children[3].Bounds);
+        }
     }
 }
diff --git a/tests/Avalonia.UnitTests/TestRoot.cs b/tests/Avalonia.UnitTests/TestRoot.cs
index 788f2b3dae4..9ba304cab75 100644
--- a/tests/Avalonia.UnitTests/TestRoot.cs
+++ b/tests/Avalonia.UnitTests/TestRoot.cs
@@ -55,7 +55,7 @@ public TestRoot(bool useGlobalStyles, Control child)
         internal ILayoutManager LayoutManager { get; set; }
         ILayoutManager ILayoutRoot.LayoutManager => LayoutManager;
 
-        public double RenderScaling => 1;
+        public double RenderScaling => LayoutScaling;
 
         internal IRenderer Renderer { get; set; }
         internal IHitTester HitTester { get; set; }