From a26059630f19e5ec8ceb5d65aff29193ee74a036 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Tue, 1 Feb 2022 14:57:08 +0100
Subject: [PATCH 1/9] Add failing test for control template value priority.

Add tests to check that template values are assigned with Style priority and move other XAML control template tests alongside it in a new test class.
---
 .../Xaml/BasicTests.cs                        |  66 +-------
 .../Xaml/ControlTemplateTests.cs              | 143 ++++++++++++++++++
 2 files changed, 144 insertions(+), 65 deletions(-)
 create mode 100644 tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs

diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BasicTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BasicTests.cs
index f20faa2287..16685c5d2d 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BasicTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BasicTests.cs
@@ -281,70 +281,6 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             Assert.Equal(expected4, grid.RowDefinitions[3].Height);
         }
 
-        [Fact]
-        public void ControlTemplate_With_Nested_Child_Is_Operational()
-        {
-            var xaml = @"
-<ControlTemplate xmlns='https://github.com/avaloniaui'>
-    <ContentControl Name='parent'>
-        <ContentControl Name='child' />
-    </ContentControl>
-</ControlTemplate>
-";
-            var template = AvaloniaRuntimeXamlLoader.Parse<ControlTemplate>(xaml);
-
-            var parent = (ContentControl)template.Build(new ContentControl()).Control;
-
-            Assert.Equal("parent", parent.Name);
-
-            var child = parent.Content as ContentControl;
-
-            Assert.NotNull(child);
-
-            Assert.Equal("child", child.Name);
-        }
-
-        [Fact]
-        public void ControlTemplate_With_TargetType_Is_Operational()
-        {
-            var xaml = @"
-<ControlTemplate xmlns='https://github.com/avaloniaui' 
-                 xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
-                 TargetType='{x:Type ContentControl}'>
-    <ContentPresenter Content='{TemplateBinding Content}' />
-</ControlTemplate>
-";
-            var template = AvaloniaRuntimeXamlLoader.Parse<ControlTemplate>(xaml);
-
-            Assert.Equal(typeof(ContentControl), template.TargetType);
-
-            Assert.IsType(typeof(ContentPresenter), template.Build(new ContentControl()).Control);
-        }
-
-        [Fact]
-        public void ControlTemplate_With_Panel_Children_Are_Added()
-        {
-            var xaml = @"
-<ControlTemplate xmlns='https://github.com/avaloniaui'>
-    <Panel Name='panel'>
-        <ContentControl Name='Foo' />
-        <ContentControl Name='Bar' />
-    </Panel>
-</ControlTemplate>
-";
-            var template = AvaloniaRuntimeXamlLoader.Parse<ControlTemplate>(xaml);
-
-            var panel = (Panel)template.Build(new ContentControl()).Control;
-
-            Assert.Equal(2, panel.Children.Count);
-
-            var foo = panel.Children[0];
-            var bar = panel.Children[1];
-
-            Assert.Equal("Foo", foo.Name);
-            Assert.Equal("Bar", bar.Name);
-        }
-
         [Fact]
         public void Named_x_Control_Is_Added_To_NameScope_Simple()
         {
@@ -361,7 +297,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
         }
 
         [Fact]
-        public void Standart_TypeConverter_Is_Used()
+        public void Standard_TypeConverter_Is_Used()
         {
             var xaml = @"<UserControl xmlns='https://github.com/avaloniaui' Width='200.5' />";
 
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
new file mode 100644
index 0000000000..fbb16d9f2e
--- /dev/null
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
@@ -0,0 +1,143 @@
+using Avalonia.Controls;
+using Avalonia.Controls.Presenters;
+using Avalonia.Data;
+using Avalonia.Diagnostics;
+using Avalonia.Markup.Xaml.Templates;
+using Avalonia.Media;
+using Avalonia.UnitTests;
+using Xunit;
+
+namespace Avalonia.Markup.Xaml.UnitTests.Xaml
+{
+    public class ControlTemplateTests : XamlTestBase
+    {
+        [Fact]
+        public void Inline_ControlTemplate_Values_Are_Set_With_Style_Priority()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <Button>
+        <Button.Template>
+            <ControlTemplate>
+                <ContentPresenter Name='PART_ContentPresenter'
+                                  Background='Red'/>
+            </ControlTemplate>
+        </Button.Template>
+    </Button>
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var button = (Button)window.Content;
+
+                window.ApplyTemplate();
+                button.ApplyTemplate();
+
+                var presenter = (ContentPresenter)button.Presenter;
+                Assert.Equal(Brushes.Red, presenter.Background);
+
+                var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
+                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+            }
+        }
+
+        [Fact]
+        public void Style_ControlTemplate_Values_Are_Set_With_Style_Priority()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <Window.Styles>
+        <Style Selector='Button'>
+            <Setter Property='Template'>
+                <ControlTemplate>
+                    <ContentPresenter Name='PART_ContentPresenter'
+                                      Background='Red'/>
+                </ControlTemplate>
+            </Setter>
+        </Style>
+    </Window.Styles>
+    <Button/>
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var button = (Button)window.Content;
+
+                window.ApplyTemplate();
+                button.ApplyTemplate();
+
+                var presenter = (ContentPresenter)button.Presenter;
+                Assert.Equal(Brushes.Red, presenter.Background);
+
+                var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
+                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+            }
+        }
+
+        [Fact]
+        public void ControlTemplate_With_Nested_Child_Is_Operational()
+        {
+            var xaml = @"
+<ControlTemplate xmlns='https://github.com/avaloniaui'>
+    <ContentControl Name='parent'>
+        <ContentControl Name='child' />
+    </ContentControl>
+</ControlTemplate>
+";
+            var template = AvaloniaRuntimeXamlLoader.Parse<ControlTemplate>(xaml);
+
+            var parent = (ContentControl)template.Build(new ContentControl()).Control;
+
+            Assert.Equal("parent", parent.Name);
+
+            var child = parent.Content as ContentControl;
+
+            Assert.NotNull(child);
+
+            Assert.Equal("child", child.Name);
+        }
+
+        [Fact]
+        public void ControlTemplate_With_TargetType_Is_Operational()
+        {
+            var xaml = @"
+<ControlTemplate xmlns='https://github.com/avaloniaui' 
+                 xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+                 TargetType='{x:Type ContentControl}'>
+    <ContentPresenter Content='{TemplateBinding Content}' />
+</ControlTemplate>
+";
+            var template = AvaloniaRuntimeXamlLoader.Parse<ControlTemplate>(xaml);
+
+            Assert.Equal(typeof(ContentControl), template.TargetType);
+
+            Assert.IsType(typeof(ContentPresenter), template.Build(new ContentControl()).Control);
+        }
+
+        [Fact]
+        public void ControlTemplate_With_Panel_Children_Are_Added()
+        {
+            var xaml = @"
+<ControlTemplate xmlns='https://github.com/avaloniaui'>
+    <Panel Name='panel'>
+        <ContentControl Name='Foo' />
+        <ContentControl Name='Bar' />
+    </Panel>
+</ControlTemplate>
+";
+            var template = AvaloniaRuntimeXamlLoader.Parse<ControlTemplate>(xaml);
+
+            var panel = (Panel)template.Build(new ContentControl()).Control;
+
+            Assert.Equal(2, panel.Children.Count);
+
+            var foo = panel.Children[0];
+            var bar = panel.Children[1];
+
+            Assert.Equal("Foo", foo.Name);
+            Assert.Equal("Bar", bar.Name);
+        }
+    }
+}

From ba8026b1b97456137f8978f3b7c61fd79f3dc030 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Tue, 1 Feb 2022 15:50:31 +0100
Subject: [PATCH 2/9] WIP: Trying to use Style priority for ControlTemplate
 values.

---
 .../AvaloniaXamlIlCompiler.cs                 |  1 +
 ...amlIlControlTemplatePriorityTransformer.cs | 37 +++++++++++++++++
 .../AvaloniaXamlIlWellKnownTypes.cs           |  2 +
 .../XamlIlAvaloniaPropertyHelper.cs           | 41 ++++++++++++++++++-
 4 files changed, 80 insertions(+), 1 deletion(-)
 create mode 100644 src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs

diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs
index 1ca7be67a7..46af0c81f5 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs
@@ -65,6 +65,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
                 new AvaloniaXamlIlCompiledBindingsMetadataRemover()
                 );
 
+            Transformers.Add(new AvaloniaXamlIlControlTemplatePriorityTransformer());
             Transformers.Add(new AvaloniaXamlIlMetadataRemover());
             Transformers.Add(new AvaloniaXamlIlRootObjectScope());
 
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
new file mode 100644
index 0000000000..22f1a8bc00
--- /dev/null
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
@@ -0,0 +1,37 @@
+using System.Linq;
+using XamlX.Ast;
+using XamlX.Transform;
+
+namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
+{
+    /// <summary>
+    /// Transforms property assignments within ControlTemplates to use Style priority where possible.
+    /// </summary>
+    class AvaloniaXamlIlControlTemplatePriorityTransformer : IXamlAstTransformer
+    {
+        public IXamlAstNode Transform(AstTransformationContext context, IXamlAstNode node)
+        {
+            var bindingPriorityType = context.GetAvaloniaTypes().BindingPriority;
+
+            if (node is XamlPropertyAssignmentNode prop &&
+                prop.Property is XamlIlAvaloniaProperty avaloniaProperty &&
+                context.ParentNodes().Any(IsControlTemplate))
+            {
+                // If there are any setters which accept a binding priority, then add the Style
+                // binding priority as a value.
+                if (avaloniaProperty.Setters.Any(x => x.Parameters[0] == bindingPriorityType))
+                {
+                    prop.Values.Insert(0, new XamlConstantNode(node, bindingPriorityType, 1));
+                }
+            }
+
+            return node;
+        }
+
+        private static bool IsControlTemplate(IXamlAstNode node)
+        {
+            return node is AvaloniaXamlIlTargetTypeMetadataNode tt &&
+                tt.ScopeType == AvaloniaXamlIlTargetTypeMetadataNode.ScopeTypes.ControlTemplate;
+        }
+    }
+}
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs
index 89b88790dc..eb3b7b8f7e 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs
@@ -15,6 +15,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
         public IXamlType AvaloniaObjectExtensions { get; }
         public IXamlType AvaloniaProperty { get; }
         public IXamlType AvaloniaPropertyT { get; }
+        public IXamlType StyledPropertyT { get; }
         public IXamlType AvaloniaAttachedPropertyT { get; }
         public IXamlType IBinding { get; }
         public IXamlMethod AvaloniaObjectBindMethod { get; }
@@ -94,6 +95,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             AvaloniaObjectExtensions = cfg.TypeSystem.GetType("Avalonia.AvaloniaObjectExtensions");
             AvaloniaProperty = cfg.TypeSystem.GetType("Avalonia.AvaloniaProperty");
             AvaloniaPropertyT = cfg.TypeSystem.GetType("Avalonia.AvaloniaProperty`1");
+            StyledPropertyT = cfg.TypeSystem.GetType("Avalonia.StyledProperty`1");
             AvaloniaAttachedPropertyT = cfg.TypeSystem.GetType("Avalonia.AttachedProperty`1");
             BindingPriority = cfg.TypeSystem.GetType("Avalonia.Data.BindingPriority");
             IBinding = cfg.TypeSystem.GetType("Avalonia.Data.IBinding");
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
index 7f1b8caf0d..6c61ad0705 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
@@ -189,7 +189,13 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             CustomAttributes = original.CustomAttributes;
             if (!original.CustomAttributes.Any(ca => ca.Type.Equals(types.AssignBindingAttribute)))
                 Setters.Insert(0, new BindingSetter(types, original.DeclaringType, field));
-            
+
+            if (field.FieldType.GenericTypeDefinition == types.StyledPropertyT)
+            {
+                var propertyType = field.FieldType.GenericArguments[0];
+                Setters.Insert(1, new SetValueWithPrioritySetter(types, original.DeclaringType, field, propertyType));
+            }
+
             Setters.Insert(0, new UnsetValueSetter(types, original.DeclaringType, field));
         }
 
@@ -240,6 +246,39 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             }
         }
 
+        class SetValueWithPrioritySetter : AvaloniaPropertyCustomSetter
+        {
+            public SetValueWithPrioritySetter(AvaloniaXamlIlWellKnownTypes types, IXamlType declaringType, IXamlField avaloniaProperty,
+                IXamlType propertyType)
+                : base(types, declaringType, avaloniaProperty)
+            {
+                Parameters = new[] { types.BindingPriority, propertyType };
+            }
+
+            public override void Emit(IXamlILEmitter emitter)
+            {
+                var method = Types.AvaloniaObject
+                    .FindMethod(m => m.IsPublic && !m.IsStatic && m.Name == "SetValue"
+                                     && m.Parameters.Count == 3
+                                     && m.Parameters[0].Name == "StyledPropertyBase`1"
+                                     && m.Parameters[2].Equals(Types.BindingPriority));
+
+                if (method == null)
+                    throw new XamlTypeSystemException(
+                        $"Unable to find AvaloniaObject.SetValue<T>(StyledPropertyBase<T>, T, BindingPriority).");
+
+                method = method.MakeGenericMethod(new[] { Parameters[1] });
+
+                using (var bloc = emitter.LocalsPool.GetLocal(Parameters[1]))
+                    emitter
+                        .Stloc(bloc.Local)
+                        .Ldsfld(AvaloniaProperty)
+                        .Ldloc(bloc.Local)
+                        .Ldc_I4(0)
+                        .EmitCall(method, true);
+            }
+        }
+
         class UnsetValueSetter : AvaloniaPropertyCustomSetter
         {
             public UnsetValueSetter(AvaloniaXamlIlWellKnownTypes types, IXamlType declaringType, IXamlField avaloniaProperty) 

From 598966a725d7e861d42ba1271ab6b8ef012f3ca5 Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Sat, 19 Feb 2022 18:42:33 +0300
Subject: [PATCH 3/9] Fixed template BindingPriority rewriter

---
 .../Avalonia.Build.Tasks.csproj               |  3 ++
 ...amlIlControlTemplatePriorityTransformer.cs | 12 +++++--
 .../AvaloniaXamlIlWellKnownTypes.cs           |  6 ++++
 .../XamlIlAvaloniaPropertyHelper.cs           | 32 +++++++++----------
 .../Avalonia.Markup.Xaml.Loader/xamlil.github |  2 +-
 5 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/src/Avalonia.Build.Tasks/Avalonia.Build.Tasks.csproj b/src/Avalonia.Build.Tasks/Avalonia.Build.Tasks.csproj
index e864ea2007..da17b80e25 100644
--- a/src/Avalonia.Build.Tasks/Avalonia.Build.Tasks.csproj
+++ b/src/Avalonia.Build.Tasks/Avalonia.Build.Tasks.csproj
@@ -89,6 +89,9 @@
       <Compile Include="../Avalonia.Controls/GridLength.cs">
         <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
       </Compile>
+      <Compile Include="../Avalonia.Base/Data/BindingPriority.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
       <Compile Include="..\Avalonia.Base\Metadata\NullableAttributes.cs" Link="NullableAttributes.cs" />
       <Compile Remove="../Markup/Avalonia.Markup.Xaml.Loader\xamlil.github\**\obj\**\*.cs" />
       <Compile Remove="../Markup/Avalonia.Markup.Xaml.Loader\xamlil.github\src\XamlX\IL\SreTypeSystem.cs" />
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
index 22f1a8bc00..fceebf860d 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
@@ -1,4 +1,6 @@
+using System.Collections.Generic;
 using System.Linq;
+using Avalonia.Data;
 using XamlX.Ast;
 using XamlX.Transform;
 
@@ -19,9 +21,15 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             {
                 // If there are any setters which accept a binding priority, then add the Style
                 // binding priority as a value.
-                if (avaloniaProperty.Setters.Any(x => x.Parameters[0] == bindingPriorityType))
+                var setPriorityValueSetter =
+                    avaloniaProperty.Setters.FirstOrDefault(x => x.Parameters[0] == bindingPriorityType);
+                
+                if(setPriorityValueSetter != null 
+                   && prop.Values.Count == 1
+                   && setPriorityValueSetter.Parameters[1].IsAssignableFrom(prop.Values[0].Type.GetClrType()))
                 {
-                    prop.Values.Insert(0, new XamlConstantNode(node, bindingPriorityType, 1));
+                    prop.PossibleSetters = new List<IXamlPropertySetter> { setPriorityValueSetter };
+                    prop.Values.Insert(0, new XamlConstantNode(node, bindingPriorityType, (int)BindingPriority.Style));
                 }
             }
 
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs
index eb3b7b8f7e..cc84fb0e52 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs
@@ -16,6 +16,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
         public IXamlType AvaloniaProperty { get; }
         public IXamlType AvaloniaPropertyT { get; }
         public IXamlType StyledPropertyT { get; }
+        public IXamlMethod AvaloniaObjectSetStyledPropertyValue { get; }
         public IXamlType AvaloniaAttachedPropertyT { get; }
         public IXamlType IBinding { get; }
         public IXamlMethod AvaloniaObjectBindMethod { get; }
@@ -98,6 +99,11 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             StyledPropertyT = cfg.TypeSystem.GetType("Avalonia.StyledProperty`1");
             AvaloniaAttachedPropertyT = cfg.TypeSystem.GetType("Avalonia.AttachedProperty`1");
             BindingPriority = cfg.TypeSystem.GetType("Avalonia.Data.BindingPriority");
+            AvaloniaObjectSetStyledPropertyValue = AvaloniaObject
+                .FindMethod(m => m.IsPublic && !m.IsStatic && m.Name == "SetValue"
+                                 && m.Parameters.Count == 3
+                                 && m.Parameters[0].Name == "StyledPropertyBase`1"
+                                 && m.Parameters[2].Equals(BindingPriority));
             IBinding = cfg.TypeSystem.GetType("Avalonia.Data.IBinding");
             IDisposable = cfg.TypeSystem.GetType("System.IDisposable");
             Transitions = cfg.TypeSystem.GetType("Avalonia.Animation.Transitions");
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
index 6c61ad0705..a568cbcef4 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
@@ -257,24 +257,24 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
 
             public override void Emit(IXamlILEmitter emitter)
             {
-                var method = Types.AvaloniaObject
-                    .FindMethod(m => m.IsPublic && !m.IsStatic && m.Name == "SetValue"
-                                     && m.Parameters.Count == 3
-                                     && m.Parameters[0].Name == "StyledPropertyBase`1"
-                                     && m.Parameters[2].Equals(Types.BindingPriority));
-
-                if (method == null)
-                    throw new XamlTypeSystemException(
-                        $"Unable to find AvaloniaObject.SetValue<T>(StyledPropertyBase<T>, T, BindingPriority).");
-
-                method = method.MakeGenericMethod(new[] { Parameters[1] });
-
-                using (var bloc = emitter.LocalsPool.GetLocal(Parameters[1]))
+                /*
+                  Current stack:
+                   - object
+                   - binding priority
+                   - value
+                */
+
+                var method = Types.AvaloniaObjectSetStyledPropertyValue
+                    .MakeGenericMethod(new[] { Parameters[1] });
+
+                using (var valueLocal = emitter.LocalsPool.GetLocal(Parameters[1]))
+                using (var priorityLocal = emitter.LocalsPool.GetLocal(Types.Int))
                     emitter
-                        .Stloc(bloc.Local)
+                        .Stloc(valueLocal.Local)
+                        .Stloc(priorityLocal.Local)
                         .Ldsfld(AvaloniaProperty)
-                        .Ldloc(bloc.Local)
-                        .Ldc_I4(0)
+                        .Ldloc(valueLocal.Local)
+                        .Ldloc(priorityLocal.Local)
                         .EmitCall(method, true);
             }
         }
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github b/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github
index 8e20d65eb5..e0cfcd0ef6 160000
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github
@@ -1 +1 @@
-Subproject commit 8e20d65eb5f1efbae08e49b18f39bfdce32df7b3
+Subproject commit e0cfcd0ef687e613ef8905e8d0891974b68c565d

From 3c5a7caf74d6c22a26c63a5c7d787c2914e7a600 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sun, 20 Feb 2022 22:48:51 +0100
Subject: [PATCH 4/9] Fix compile errors.

---
 src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs          | 4 +++-
 .../AvaloniaXamlIlLanguageParseIntrinsics.cs                  | 2 +-
 .../Transformers/AvaloniaXamlIlSelectorTransformer.cs         | 4 ++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs b/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs
index 593d79471e..e6da450ae9 100644
--- a/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs
+++ b/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs
@@ -247,7 +247,8 @@ namespace Avalonia.Build.Tasks
                         var populateBuilder = classTypeDefinition == null ?
                             builder :
                             typeSystem.CreateTypeBuilder(classTypeDefinition);
-                        compiler.Compile(parsed, contextClass,
+                        compiler.Compile(parsed, 
+                            contextClass,
                             compiler.DefinePopulateMethod(populateBuilder, parsed, populateName,
                                 classTypeDefinition == null),
                             buildName == null ? null : compiler.DefineBuildMethod(builder, parsed, buildName, true),
@@ -255,6 +256,7 @@ namespace Avalonia.Build.Tasks
                                 true),
                             (closureName, closureBaseType) =>
                                 populateBuilder.DefineSubType(closureBaseType, closureName, false),
+                            (s, returnType, parameters) => builder.DefineDelegateSubType(s, false, returnType, parameters),
                             res.Uri, res
                         );
                         
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlLanguageParseIntrinsics.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlLanguageParseIntrinsics.cs
index 4592b9c8b4..b622971d38 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlLanguageParseIntrinsics.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlLanguageParseIntrinsics.cs
@@ -201,7 +201,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             if (type.Equals(types.Classes))
             {
                 var classes = text.Split(' ');
-                var classNodes = classes.Select(c => new XamlAstTextNode(node, c, types.XamlIlTypes.String)).ToArray();
+                var classNodes = classes.Select(c => new XamlAstTextNode(node, c, type: types.XamlIlTypes.String)).ToArray();
 
                 result = new AvaloniaXamlIlAvaloniaListConstantAstNode(node, types, types.Classes, types.XamlIlTypes.String, classNodes);
                 return true;
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlSelectorTransformer.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlSelectorTransformer.cs
index 79589a5a4f..4c4df1f53a 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlSelectorTransformer.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlSelectorTransformer.cs
@@ -77,7 +77,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                                 throw new XamlParseException($"Cannot find '{property.Property}' on '{type}", node);
 
                             if (!XamlTransformHelpers.TryGetCorrectlyTypedValue(context,
-                                new XamlAstTextNode(node, property.Value, context.Configuration.WellKnownTypes.String),
+                                new XamlAstTextNode(node, property.Value, type: context.Configuration.WellKnownTypes.String),
                                 targetProperty.PropertyType, out var typedValue))
                                 throw new XamlParseException(
                                     $"Cannot convert '{property.Value}' to '{targetProperty.PropertyType.GetFqn()}",
@@ -118,7 +118,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                                     .GetAvaloniaPropertyType(targetPropertyField, context.GetAvaloniaTypes(), node);
 
                                 if (!XamlTransformHelpers.TryGetCorrectlyTypedValue(context,
-                                    new XamlAstTextNode(node, attachedProperty.Value, context.Configuration.WellKnownTypes.String),
+                                    new XamlAstTextNode(node, attachedProperty.Value, type: context.Configuration.WellKnownTypes.String),
                                     targetPropertyType, out var typedValue))
                                         throw new XamlParseException(
                                             $"Cannot convert '{attachedProperty.Value}' to '{targetPropertyType.GetFqn()}",

From 351be2f4b271fded6405bb9663f3f6c5d69053f3 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sun, 20 Feb 2022 23:33:15 +0100
Subject: [PATCH 5/9] Use style priority for attached values in templates.

---
 ...amlIlControlTemplatePriorityTransformer.cs | 14 +++-
 .../XamlIlAvaloniaPropertyHelper.cs           |  5 +-
 .../Xaml/ControlTemplateTests.cs              | 66 ++++++++++++++++++-
 3 files changed, 79 insertions(+), 6 deletions(-)

diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
index fceebf860d..eede21396d 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
@@ -15,12 +15,19 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
         {
             var bindingPriorityType = context.GetAvaloniaTypes().BindingPriority;
 
+            // The node is a candidate for transformation if:
+            // - It's a property assignment to an Avalonia property
+            // - There's a ControlTemplate ancestor
+            // - There's just a direct call setter available
             if (node is XamlPropertyAssignmentNode prop &&
                 prop.Property is XamlIlAvaloniaProperty avaloniaProperty &&
-                context.ParentNodes().Any(IsControlTemplate))
+                context.ParentNodes().Any(IsControlTemplate) &&
+                prop.PossibleSetters.Count == 1 &&
+                prop.PossibleSetters[0] is XamlDirectCallPropertySetter)
             {
-                // If there are any setters which accept a binding priority, then add the Style
-                // binding priority as a value.
+                // Check if there are any setters on the property which accept a binding priority -
+                // this filters the candidates down to styled and attached properties. If so, then
+                // use this setter with BindingPriority.Style.
                 var setPriorityValueSetter =
                     avaloniaProperty.Setters.FirstOrDefault(x => x.Parameters[0] == bindingPriorityType);
                 
@@ -30,6 +37,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 {
                     prop.PossibleSetters = new List<IXamlPropertySetter> { setPriorityValueSetter };
                     prop.Values.Insert(0, new XamlConstantNode(node, bindingPriorityType, (int)BindingPriority.Style));
+                    return node;
                 }
             }
 
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
index a568cbcef4..bb439b8816 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
@@ -190,7 +190,10 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             if (!original.CustomAttributes.Any(ca => ca.Type.Equals(types.AssignBindingAttribute)))
                 Setters.Insert(0, new BindingSetter(types, original.DeclaringType, field));
 
-            if (field.FieldType.GenericTypeDefinition == types.StyledPropertyT)
+            // Styled and attached properties can be set with a BindingPriority when they're
+            // assigned in a ControlTemplate.
+            if (field.FieldType.GenericTypeDefinition == types.StyledPropertyT ||
+                field.FieldType.GenericTypeDefinition == types.AvaloniaAttachedPropertyT)
             {
                 var propertyType = field.FieldType.GenericArguments[0];
                 Setters.Insert(1, new SetValueWithPrioritySetter(types, original.DeclaringType, field, propertyType));
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
index fbb16d9f2e..f74aaaed76 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
@@ -12,7 +12,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
     public class ControlTemplateTests : XamlTestBase
     {
         [Fact]
-        public void Inline_ControlTemplate_Values_Are_Set_With_Style_Priority()
+        public void Inline_ControlTemplate_Styled_Values_Are_Set_With_Style_Priority()
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
@@ -43,7 +43,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
         }
 
         [Fact]
-        public void Style_ControlTemplate_Values_Are_Set_With_Style_Priority()
+        public void Style_ControlTemplate_Styled_Values_Are_Set_With_Style_Priority()
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
@@ -76,6 +76,68 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             }
         }
 
+        [Fact]
+        public void ControlTemplate_Attached_Values_Are_Set_With_Style_Priority()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <Button>
+        <Button.Template>
+            <ControlTemplate>
+                <ContentPresenter Name='PART_ContentPresenter'
+                                  DockPanel.Dock='Top'/>
+            </ControlTemplate>
+        </Button.Template>
+    </Button>
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var button = (Button)window.Content;
+
+                window.ApplyTemplate();
+                button.ApplyTemplate();
+
+                var presenter = (ContentPresenter)button.Presenter;
+                Assert.Equal(Dock.Top, DockPanel.GetDock(presenter));
+
+                var diagnostic = presenter.GetDiagnostic(DockPanel.DockProperty);
+                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+            }
+        }
+
+        [Fact]
+        public void ControlTemplate_TemplateBindings_Are_Set_With_TemplatedParent_Priority()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <Button Content='Foo'>
+        <Button.Template>
+            <ControlTemplate>
+                <ContentPresenter Name='PART_ContentPresenter'
+                                  Content='{TemplateBinding Content}'/>
+            </ControlTemplate>
+        </Button.Template>
+    </Button>
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var button = (Button)window.Content;
+
+                window.ApplyTemplate();
+                button.ApplyTemplate();
+
+                var presenter = (ContentPresenter)button.Presenter;
+                Assert.Equal("Foo", presenter.Content);
+
+                var diagnostic = presenter.GetDiagnostic(ContentPresenter.ContentProperty);
+                Assert.Equal(BindingPriority.TemplatedParent, diagnostic.Priority);
+            }
+        }
+
         [Fact]
         public void ControlTemplate_With_Nested_Child_Is_Operational()
         {

From f7ff0a02893396f5ed28a033005d9907b97af096 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sun, 20 Feb 2022 23:48:49 +0100
Subject: [PATCH 6/9] More failing tests for ControlTemplate resources.

---
 .../Xaml/ControlTemplateTests.cs              | 68 +++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
index f74aaaed76..2c38a82031 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
@@ -107,6 +107,74 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             }
         }
 
+        [Fact]
+        public void ControlTemplate_StaticResources_Are_Set_With_Style_Priority()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <Window.Resources>
+        <SolidColorBrush x:Key='red'>Red</SolidColorBrush>
+    </Window.Resources>
+    <Button Content='Foo'>
+        <Button.Template>
+            <ControlTemplate>
+                <ContentPresenter Name='PART_ContentPresenter'
+                                  Background='{StaticResource red}'/>
+            </ControlTemplate>
+        </Button.Template>
+    </Button>
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var button = (Button)window.Content;
+
+                window.ApplyTemplate();
+                button.ApplyTemplate();
+
+                var presenter = (ContentPresenter)button.Presenter;
+                Assert.Equal(Brushes.Red, presenter.Background);
+
+                var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
+                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+            }
+        }
+
+        [Fact]
+        public void ControlTemplate_DynamicResources_Are_Set_With_Style_Priority()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <Window.Resources>
+        <SolidColorBrush x:Key='red'>Red</SolidColorBrush>
+    </Window.Resources>
+    <Button Content='Foo'>
+        <Button.Template>
+            <ControlTemplate>
+                <ContentPresenter Name='PART_ContentPresenter'
+                                  Background='{DynamicResource red}'/>
+            </ControlTemplate>
+        </Button.Template>
+    </Button>
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var button = (Button)window.Content;
+
+                window.ApplyTemplate();
+                button.ApplyTemplate();
+
+                var presenter = (ContentPresenter)button.Presenter;
+                Assert.Equal(Brushes.Red, presenter.Background);
+
+                var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
+                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+            }
+        }
+
         [Fact]
         public void ControlTemplate_TemplateBindings_Are_Set_With_TemplatedParent_Priority()
         {

From cb7488baa7ed96fedd0308f8363c7003f4484893 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Mon, 21 Feb 2022 22:54:58 +0100
Subject: [PATCH 7/9] Use Style priority for StaticResource in ControlTemplate.

---
 ...amlIlControlTemplatePriorityTransformer.cs | 33 +++++++++++--------
 .../XamlIlAvaloniaPropertyHelper.cs           | 32 ++++++++++++++++--
 .../Avalonia.Markup.Xaml.Loader/xamlil.github |  2 +-
 3 files changed, 50 insertions(+), 17 deletions(-)

diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
index eede21396d..e0090eb2e8 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
@@ -18,26 +18,31 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             // The node is a candidate for transformation if:
             // - It's a property assignment to an Avalonia property
             // - There's a ControlTemplate ancestor
-            // - There's just a direct call setter available
+            // - The property has a single value
             if (node is XamlPropertyAssignmentNode prop &&
                 prop.Property is XamlIlAvaloniaProperty avaloniaProperty &&
                 context.ParentNodes().Any(IsControlTemplate) &&
-                prop.PossibleSetters.Count == 1 &&
-                prop.PossibleSetters[0] is XamlDirectCallPropertySetter)
+                prop.Values.Count == 1)
             {
-                // Check if there are any setters on the property which accept a binding priority -
-                // this filters the candidates down to styled and attached properties. If so, then
-                // use this setter with BindingPriority.Style.
-                var setPriorityValueSetter =
-                    avaloniaProperty.Setters.FirstOrDefault(x => x.Parameters[0] == bindingPriorityType);
-                
-                if(setPriorityValueSetter != null 
-                   && prop.Values.Count == 1
-                   && setPriorityValueSetter.Parameters[1].IsAssignableFrom(prop.Values[0].Type.GetClrType()))
+                var priorityValueSetters = new List<IXamlPropertySetter>();
+
+                // Iterate through the possible setters, trying to find a setter on the property 
+                // which has a BindingPriority parameter followed by the parameter of the existing
+                // setter.
+                foreach (var setter in prop.PossibleSetters)
+                {
+                    var s = avaloniaProperty.Setters.FirstOrDefault(x => 
+                        x.Parameters[0] == bindingPriorityType &&
+                        x.Parameters[1] == setter.Parameters[0]);
+                    if (s != null)
+                        priorityValueSetters.Add(s);
+                }
+
+                // If any BindingPriority setters were found, use those.
+                if (priorityValueSetters.Count > 0)
                 {
-                    prop.PossibleSetters = new List<IXamlPropertySetter> { setPriorityValueSetter };
+                    prop.PossibleSetters = priorityValueSetters;
                     prop.Values.Insert(0, new XamlConstantNode(node, bindingPriorityType, (int)BindingPriority.Style));
-                    return node;
                 }
             }
 
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
index bb439b8816..5c7a80e680 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs
@@ -185,9 +185,11 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             AvaloniaXamlIlWellKnownTypes types)
             :base(original, original.Name, original.DeclaringType, original.Getter, original.Setters)
         {
+            var assignBinding = original.CustomAttributes.Any(ca => ca.Type.Equals(types.AssignBindingAttribute));
+
             AvaloniaProperty = field;
             CustomAttributes = original.CustomAttributes;
-            if (!original.CustomAttributes.Any(ca => ca.Type.Equals(types.AssignBindingAttribute)))
+            if (!assignBinding)
                 Setters.Insert(0, new BindingSetter(types, original.DeclaringType, field));
 
             // Styled and attached properties can be set with a BindingPriority when they're
@@ -196,7 +198,9 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
                 field.FieldType.GenericTypeDefinition == types.AvaloniaAttachedPropertyT)
             {
                 var propertyType = field.FieldType.GenericArguments[0];
-                Setters.Insert(1, new SetValueWithPrioritySetter(types, original.DeclaringType, field, propertyType));
+                Setters.Insert(0, new SetValueWithPrioritySetter(types, original.DeclaringType, field, propertyType));
+                if (!assignBinding)
+                    Setters.Insert(1, new BindingWithPrioritySetter(types, original.DeclaringType, field));
             }
 
             Setters.Insert(0, new UnsetValueSetter(types, original.DeclaringType, field));
@@ -249,6 +253,30 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             }
         }
 
+        class BindingWithPrioritySetter : AvaloniaPropertyCustomSetter
+        {
+            public BindingWithPrioritySetter(AvaloniaXamlIlWellKnownTypes types,
+                IXamlType declaringType,
+                IXamlField avaloniaProperty) : base(types, declaringType, avaloniaProperty)
+            {
+                Parameters = new[] { types.BindingPriority, types.IBinding };
+            }
+
+            public override void Emit(IXamlILEmitter emitter)
+            {
+                using (var bloc = emitter.LocalsPool.GetLocal(Types.IBinding))
+                using (var priorityLocal = emitter.LocalsPool.GetLocal(Types.Int))
+                    emitter
+                        .Stloc(bloc.Local)
+                        .Stloc(priorityLocal.Local)
+                        .Ldsfld(AvaloniaProperty)
+                        .Ldloc(bloc.Local)
+                        // TODO: provide anchor?
+                        .Ldnull();
+                emitter.EmitCall(Types.AvaloniaObjectBindMethod, true);
+            }
+        }
+
         class SetValueWithPrioritySetter : AvaloniaPropertyCustomSetter
         {
             public SetValueWithPrioritySetter(AvaloniaXamlIlWellKnownTypes types, IXamlType declaringType, IXamlField avaloniaProperty,
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github b/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github
index e0cfcd0ef6..a4897d581c 160000
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github
@@ -1 +1 @@
-Subproject commit e0cfcd0ef687e613ef8905e8d0891974b68c565d
+Subproject commit a4897d581c7f155543102f0d744a47863e1fbfea

From a142b7ea04578e2b4cc5e521a38288fe9b3cd790 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Tue, 22 Feb 2022 23:14:46 +0100
Subject: [PATCH 8/9] Detect control template from markup extensions.

Allow markup extensions to detect whether they're in a control template and use that info in `DynamicResourceExtension` to use `Style` priority.
---
 .../Avalonia.Markup.Xaml/Avalonia.Markup.Xaml.csproj      | 1 +
 src/Markup/Avalonia.Markup.Xaml/Extensions.cs             | 4 ++--
 .../MarkupExtensions/DynamicResourceExtension.cs          | 8 ++++++--
 .../Runtime/IAvaloniaXamlIlControlTemplateProvider.cs     | 8 ++++++++
 .../XamlIl/Runtime/XamlIlRuntimeHelpers.cs                | 5 ++++-
 5 files changed, 21 insertions(+), 5 deletions(-)
 create mode 100644 src/Markup/Avalonia.Markup.Xaml/XamlIl/Runtime/IAvaloniaXamlIlControlTemplateProvider.cs

diff --git a/src/Markup/Avalonia.Markup.Xaml/Avalonia.Markup.Xaml.csproj b/src/Markup/Avalonia.Markup.Xaml/Avalonia.Markup.Xaml.csproj
index 86132c5d27..4d9e216916 100644
--- a/src/Markup/Avalonia.Markup.Xaml/Avalonia.Markup.Xaml.csproj
+++ b/src/Markup/Avalonia.Markup.Xaml/Avalonia.Markup.Xaml.csproj
@@ -46,6 +46,7 @@
         <Compile Include="Templates\Template.cs" />
         <Compile Include="Templates\TemplateContent.cs" />
         <Compile Include="Templates\TreeDataTemplate.cs" />
+        <Compile Include="XamlIl\Runtime\IAvaloniaXamlIlControlTemplateProvider.cs" />
         <Compile Include="XamlIl\Runtime\IAvaloniaXamlIlParentStackProvider.cs" />
         <Compile Include="XamlIl\Runtime\IAvaloniaXamlIlXmlNamespaceInfoProviderV1.cs" />
         <Compile Include="XamlIl\Runtime\XamlIlRuntimeHelpers.cs" />
diff --git a/src/Markup/Avalonia.Markup.Xaml/Extensions.cs b/src/Markup/Avalonia.Markup.Xaml/Extensions.cs
index 263750c316..d937a83010 100644
--- a/src/Markup/Avalonia.Markup.Xaml/Extensions.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/Extensions.cs
@@ -24,10 +24,10 @@ namespace Avalonia.Markup.Xaml
         public static IEnumerable<T> GetParents<T>(this IServiceProvider sp)
         {
             return sp.GetService<IAvaloniaXamlIlParentStackProvider>().Parents.OfType<T>();
-            
-            
         }
 
+        public static bool IsInControlTemplate(this IServiceProvider sp) => sp.GetService<IAvaloniaXamlIlControlTemplateProvider>() != null;
+
         public static Type ResolveType(this IServiceProvider ctx, string namespacePrefix, string type)
         {
             var tr = ctx.GetService<IXamlTypeResolver>();
diff --git a/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/DynamicResourceExtension.cs b/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/DynamicResourceExtension.cs
index 087611bd59..65e38508bc 100644
--- a/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/DynamicResourceExtension.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/DynamicResourceExtension.cs
@@ -11,6 +11,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
     public class DynamicResourceExtension : IBinding
     {
         private object? _anchor;
+        private BindingPriority _priority;
 
         public DynamicResourceExtension()
         {
@@ -25,6 +26,9 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
 
         public IBinding ProvideValue(IServiceProvider serviceProvider)
         {
+            if (serviceProvider.IsInControlTemplate())
+                _priority = BindingPriority.Style;
+
             var provideTarget = serviceProvider.GetService<IProvideValueTarget>();
 
             if (!(provideTarget.TargetObject is IStyledElement))
@@ -53,12 +57,12 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
             if (control != null)
             {
                 var source = control.GetResourceObservable(ResourceKey, GetConverter(targetProperty));
-                return InstancedBinding.OneWay(source);
+                return InstancedBinding.OneWay(source, _priority);
             }
             else if (_anchor is IResourceProvider resourceProvider)
             {
                 var source = resourceProvider.GetResourceObservable(ResourceKey, GetConverter(targetProperty));
-                return InstancedBinding.OneWay(source);
+                return InstancedBinding.OneWay(source, _priority);
             }
 
             return null;
diff --git a/src/Markup/Avalonia.Markup.Xaml/XamlIl/Runtime/IAvaloniaXamlIlControlTemplateProvider.cs b/src/Markup/Avalonia.Markup.Xaml/XamlIl/Runtime/IAvaloniaXamlIlControlTemplateProvider.cs
new file mode 100644
index 0000000000..ed3f5bfdff
--- /dev/null
+++ b/src/Markup/Avalonia.Markup.Xaml/XamlIl/Runtime/IAvaloniaXamlIlControlTemplateProvider.cs
@@ -0,0 +1,8 @@
+using System.Collections.Generic;
+
+namespace Avalonia.Markup.Xaml.XamlIl.Runtime
+{
+    public interface IAvaloniaXamlIlControlTemplateProvider
+    {
+    }
+}
diff --git a/src/Markup/Avalonia.Markup.Xaml/XamlIl/Runtime/XamlIlRuntimeHelpers.cs b/src/Markup/Avalonia.Markup.Xaml/XamlIl/Runtime/XamlIlRuntimeHelpers.cs
index c48f386ffd..a0e7fd7dcf 100644
--- a/src/Markup/Avalonia.Markup.Xaml/XamlIl/Runtime/XamlIlRuntimeHelpers.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/XamlIl/Runtime/XamlIlRuntimeHelpers.cs
@@ -42,7 +42,8 @@ namespace Avalonia.Markup.Xaml.XamlIl.Runtime
         class DeferredParentServiceProvider :
             IAvaloniaXamlIlParentStackProvider,
             IServiceProvider,
-            IRootObjectProvider
+            IRootObjectProvider,
+            IAvaloniaXamlIlControlTemplateProvider
         {
             private readonly IServiceProvider _parentProvider;
             private readonly List<IResourceNode> _parentResourceNodes;
@@ -75,6 +76,8 @@ namespace Avalonia.Markup.Xaml.XamlIl.Runtime
                     return this;
                 if (serviceType == typeof(IRootObjectProvider))
                     return this;
+                if (serviceType == typeof(IAvaloniaXamlIlControlTemplateProvider))
+                    return this;
                 return _parentProvider?.GetService(serviceType);
             }
 

From beaf956af72b4ad38a56f92b6d9ec048fedb2815 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Tue, 22 Feb 2022 23:23:15 +0100
Subject: [PATCH 9/9] Use TemplatedParent priority in ControlTemplates.

---
 ...AvaloniaXamlIlControlTemplatePriorityTransformer.cs |  2 +-
 .../MarkupExtensions/DynamicResourceExtension.cs       |  2 +-
 .../Xaml/ControlTemplateTests.cs                       | 10 +++++-----
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
index e0090eb2e8..6cab68e756 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlControlTemplatePriorityTransformer.cs
@@ -42,7 +42,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 if (priorityValueSetters.Count > 0)
                 {
                     prop.PossibleSetters = priorityValueSetters;
-                    prop.Values.Insert(0, new XamlConstantNode(node, bindingPriorityType, (int)BindingPriority.Style));
+                    prop.Values.Insert(0, new XamlConstantNode(node, bindingPriorityType, (int)BindingPriority.TemplatedParent));
                 }
             }
 
diff --git a/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/DynamicResourceExtension.cs b/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/DynamicResourceExtension.cs
index 65e38508bc..f13ecab4e1 100644
--- a/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/DynamicResourceExtension.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/DynamicResourceExtension.cs
@@ -27,7 +27,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
         public IBinding ProvideValue(IServiceProvider serviceProvider)
         {
             if (serviceProvider.IsInControlTemplate())
-                _priority = BindingPriority.Style;
+                _priority = BindingPriority.TemplatedParent;
 
             var provideTarget = serviceProvider.GetService<IProvideValueTarget>();
 
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
index 2c38a82031..2d6ed1dc62 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
@@ -38,7 +38,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 Assert.Equal(Brushes.Red, presenter.Background);
 
                 var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
-                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+                Assert.Equal(BindingPriority.TemplatedParent, diagnostic.Priority);
             }
         }
 
@@ -72,7 +72,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 Assert.Equal(Brushes.Red, presenter.Background);
 
                 var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
-                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+                Assert.Equal(BindingPriority.TemplatedParent, diagnostic.Priority);
             }
         }
 
@@ -103,7 +103,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 Assert.Equal(Dock.Top, DockPanel.GetDock(presenter));
 
                 var diagnostic = presenter.GetDiagnostic(DockPanel.DockProperty);
-                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+                Assert.Equal(BindingPriority.TemplatedParent, diagnostic.Priority);
             }
         }
 
@@ -137,7 +137,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 Assert.Equal(Brushes.Red, presenter.Background);
 
                 var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
-                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+                Assert.Equal(BindingPriority.TemplatedParent, diagnostic.Priority);
             }
         }
 
@@ -171,7 +171,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 Assert.Equal(Brushes.Red, presenter.Background);
 
                 var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
-                Assert.Equal(BindingPriority.Style, diagnostic.Priority);
+                Assert.Equal(BindingPriority.TemplatedParent, diagnostic.Priority);
             }
         }