From f9c1570ac63b45436ff31c7b9a7c36334c28b47c Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Sun, 22 Feb 2026 14:32:01 +0500
Subject: [PATCH] Fixed incorrect opacity stack handling (#20730)

---
 .../ServerCompositionVisual.Render.cs         |   3 +-
 tests/Avalonia.RenderTests/BugRepros.cs       |  55 ++++++++++++++++++
 ..._Should_Not_Affect_Each_Other.expected.png | Bin 0 -> 1896 bytes
 3 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 tests/Avalonia.RenderTests/BugRepros.cs
 create mode 100644 tests/TestFiles/Skia/BugRepros/Sibling_Visuals_With_Opacity_Should_Not_Affect_Each_Other.expected.png

diff --git a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual/ServerCompositionVisual.Render.cs b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual/ServerCompositionVisual.Render.cs
index d2dd0346d6..8d8b862bb3 100644
--- a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual/ServerCompositionVisual.Render.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual/ServerCompositionVisual.Render.cs
@@ -94,7 +94,8 @@ partial class ServerCompositionVisual
             
             if (visual.Opacity != 1)
             {
-                _opacityStack.Push(effectiveOpacity);
+                _opacityStack.Push(_opacity);
+                _opacity = effectiveOpacity;
                 _canvas.PushOpacity(visual.Opacity, visual._transformedSubTreeBounds.Value.ToRect());
             }
 
diff --git a/tests/Avalonia.RenderTests/BugRepros.cs b/tests/Avalonia.RenderTests/BugRepros.cs
new file mode 100644
index 0000000000..02d41569a6
--- /dev/null
+++ b/tests/Avalonia.RenderTests/BugRepros.cs
@@ -0,0 +1,55 @@
+using Avalonia.Controls;
+using Avalonia.Controls.Shapes;
+using Avalonia.Layout;
+using Avalonia.Media;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Avalonia.Skia.RenderTests;
+
+public class BugRepros() : TestBase(nameof(BugRepros))
+{
+    [Fact]
+    public async Task Sibling_Visuals_With_Opacity_Should_Not_Affect_Each_Other()
+    {
+        var brushes = new IBrush[]
+        {
+            Brushes.Red,
+            Brushes.Green,
+            Brushes.Blue,
+            Brushes.Yellow,
+            Brushes.Magenta,
+            Brushes.Cyan,
+            Brushes.Orange,
+            Brushes.Purple,
+            Brushes.Pink,
+            Brushes.Brown
+        };
+
+        var stackPanel = new StackPanel
+        {
+            Orientation = Orientation.Vertical,
+            Width = 300,
+            Height = 500,
+            Background = Brushes.White,
+        };
+
+        for (int i = 0; i < brushes.Length; i++)
+        {
+            var border = new Border
+            {
+                Width = 280,
+                Height = 40,
+                BorderThickness = new Thickness(2),
+                Margin = new Thickness(5),
+                Background = brushes[i],
+                Opacity = 0.3
+            };
+            stackPanel.Children.Add(border);
+        }
+
+        await RenderToFile(stackPanel);
+        CompareImages();
+    }
+}
diff --git a/tests/TestFiles/Skia/BugRepros/Sibling_Visuals_With_Opacity_Should_Not_Affect_Each_Other.expected.png b/tests/TestFiles/Skia/BugRepros/Sibling_Visuals_With_Opacity_Should_Not_Affect_Each_Other.expected.png
new file mode 100644
index 0000000000000000000000000000000000000000..328c1a3e7d58edf0db4855531ce17ec266289702
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