feat: Allow for key override for non-ignored namespaces

src/UWP/TestLibrary/Generated/mergedpages01.xaml

@@ -16,6 +16,11 @@
     <ResourceDictionary Source="ms-appx:///TestLibrary/Colors.xaml" />
     <ResourceDictionary Source="ms-appx:///TestLibrary/Colors.xaml" />
     <ResourceDictionary Source="ms-appx:///TestLibrary/Colors.xaml" />
+    <ResourceDictionary Source="ms-appx:///TestLibrary/Colors.xaml" />
+    <ResourceDictionary Source="ms-appx:///TestLibrary/Colors.xaml" />
+    <ResourceDictionary Source="ms-appx:///TestLibrary/Colors.xaml" />
+    <ResourceDictionary Source="ms-appx:///TestLibrary/Colors.xaml" />
+    <ResourceDictionary Source="ms-appx:///TestLibrary/Colors.xaml" />
   </ResourceDictionary.MergedDictionaries>
   <ResourceDictionary.ThemeDictionaries>
     <ResourceDictionary x:Key="Default">
@@ -172,6 +177,51 @@
       </Setter.Value>
     </Setter>
   </xamarin:Style>
+  <xamarin:Style TargetType="ItemsControl">
+    <Setter Property="Template">
+      <Setter.Value>
+        <ControlTemplate TargetType="ItemsControl">
+          <ItemsPresenter Padding="{TemplateBinding Padding}" />
+        </ControlTemplate>
+      </Setter.Value>
+    </Setter>
+  </xamarin:Style>
+  <xamarin:Style TargetType="ItemsControl">
+    <Setter Property="Template">
+      <Setter.Value>
+        <ControlTemplate TargetType="ItemsControl">
+          <ItemsPresenter Padding="{TemplateBinding Padding}" />
+        </ControlTemplate>
+      </Setter.Value>
+    </Setter>
+  </xamarin:Style>
+  <xamarin:Style TargetType="ItemsControl">
+    <Setter Property="Template">
+      <Setter.Value>
+        <ControlTemplate TargetType="ItemsControl">
+          <ItemsPresenter Padding="{TemplateBinding Padding}" />
+        </ControlTemplate>
+      </Setter.Value>
+    </Setter>
+  </xamarin:Style>
+  <xamarin:Style TargetType="ItemsControl">
+    <Setter Property="Template">
+      <Setter.Value>
+        <ControlTemplate TargetType="ItemsControl">
+          <ItemsPresenter Padding="{TemplateBinding Padding}" />
+        </ControlTemplate>
+      </Setter.Value>
+    </Setter>
+  </xamarin:Style>
+  <xamarin:Style TargetType="ItemsControl">
+    <Setter Property="Template">
+      <Setter.Value>
+        <ControlTemplate TargetType="ItemsControl">
+          <ItemsPresenter Padding="{TemplateBinding Padding}" />
+        </ControlTemplate>
+      </Setter.Value>
+    </Setter>
+  </xamarin:Style>
   <!--origin: Generated\mergedpages02.xaml-->
   <!--origin: Inner1\Colors.xaml-->
   <!--origin: Inner1\ImplicitConflict.xaml-->

src/Uno.XamlMerge.Task/MergedDictionary.cs

@@ -246,7 +246,13 @@ private void AddNode(XmlNode node, Dictionary<string, string> xmlnsReplacementDi
                 // if it's not, or if we haven't seen a previous node with this key, then we'll just
                 // add it to our list.
                 string simpleNodeKey = GetKey(node);
-                string nodeKey = simpleNodeKey + node.Prefix;
+                var currentIgnorables = BuildIgnorables();
+
+                // We need allow ignored keys as they may be used to provide
+                // per-platform styles based on uno's selective ignorables.
+                string nodeKey = (currentIgnorables?.Contains(node.Prefix) ?? false)
+                    ? simpleNodeKey + node.Prefix
+                    : simpleNodeKey;
 
                 if (simpleNodeKey.Length == 0 || !nodeKeyToNodeListIndexDictionary.ContainsKey(nodeKey))
                 {
@@ -275,6 +281,30 @@ private void AddNode(XmlNode node, Dictionary<string, string> xmlnsReplacementDi
             }
         }
 
+        private string[] BuildIgnorables()
+        {
+            HashSet<string> result = new();
+
+            var current = this;
+
+            do
+            {
+                var nsList = current._ignorablesAttribute?.Value.Split(' ') ?? Array.Empty<string>();
+
+                foreach (var ns in nsList)
+                {
+                    if (!result.Contains(ns))
+                    {
+                        result.Add(ns);
+                    }
+                }
+                current = current.parentDictionary;
+
+            } while (current != null);
+
+            return result.ToArray();
+        }
+
         private XmlNode GetXaml()
         {
             if (parentDictionary == null)

src/Uno.XamlMerge.Tests/Given_BatchMergeXaml.cs

@@ -47,6 +47,37 @@ public void When_Duplicate_Keys_Different_Namespace_Single_Input()
         ValidateOutput(task);
     }
 
+    [TestMethod]
+    public void When_Duplicate_ThemeResources()
+    {
+        var task = CreateMerger();
+
+        Assert.IsTrue(task.Execute());
+
+        ValidateOutput(task);
+    }
+
+    [TestMethod]
+    public void When_Duplicate_ThemeResources_With_Prefix()
+    {
+        var task = CreateMerger();
+
+        Assert.IsTrue(task.Execute());
+
+        ValidateOutput(task);
+    }
+
+
+    [TestMethod]
+    public void When_Duplicate_ThemeResources_With_Ignored_Prefix()
+    {
+        var task = CreateMerger();
+
+        Assert.IsTrue(task.Execute());
+
+        ValidateOutput(task);
+    }
+
     [TestMethod]
     public void When_Duplicate_Keys_Different_Namespace_Multiple_Input()
     {

src/Uno.XamlMerge.Tests/Scenarios/When_Duplicate_ThemeResources/Input_Dictionary_1.xml

@@ -0,0 +1,7 @@
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="netstdref wasm skia not_win" xmlns:contract7Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:contract7NotPresent="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:netstdref="http://uno.ui/netstdref" xmlns:wasm="http://uno.ui/wasm" xmlns:skia="http://uno.ui/skia" xmlns:not_win="http://uno.ui/not_win" xmlns:win="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<ResourceDictionary.ThemeDictionaries>
+		<ResourceDictionary x:Key="Default">
+			<Thickness x:Key="FlipViewButtonBorderThemeThickness">1</Thickness>
+		</ResourceDictionary>
+	</ResourceDictionary.ThemeDictionaries>
+</ResourceDictionary>

src/Uno.XamlMerge.Tests/Scenarios/When_Duplicate_ThemeResources/Input_Dictionary_2.xml

@@ -0,0 +1,7 @@
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="netstdref wasm skia not_win" xmlns:contract7Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:contract7NotPresent="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:netstdref="http://uno.ui/netstdref" xmlns:wasm="http://uno.ui/wasm" xmlns:skia="http://uno.ui/skia" xmlns:not_win="http://uno.ui/not_win" xmlns:win="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<ResourceDictionary.ThemeDictionaries>
+		<ResourceDictionary x:Key="Default">
+			<Thickness x:Key="FlipViewButtonBorderThemeThickness">2</Thickness>
+		</ResourceDictionary>
+	</ResourceDictionary.ThemeDictionaries>
+</ResourceDictionary>

src/Uno.XamlMerge.Tests/Scenarios/When_Duplicate_ThemeResources/expected.xml

@@ -0,0 +1,9 @@
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="netstdref wasm skia not_win" xmlns:contract7Present="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:contract7NotPresent="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractNotPresent(Windows.Foundation.UniversalApiContract,7)" xmlns:netstdref="http://uno.ui/netstdref" xmlns:wasm="http://uno.ui/wasm" xmlns:skia="http://uno.ui/skia" xmlns:not_win="http://uno.ui/not_win" xmlns:win="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<ResourceDictionary.ThemeDictionaries>
+		<ResourceDictionary x:Key="Default">
+			<Thickness x:Key="FlipViewButtonBorderThemeThickness">2</Thickness>
+		</ResourceDictionary>
+	</ResourceDictionary.ThemeDictionaries>
+	<!--origin: When_Duplicate_ThemeResources\Input_Dictionary_1.xml-->
+	<!--origin: When_Duplicate_ThemeResources\Input_Dictionary_2.xml-->
+</ResourceDictionary>

src/Uno.XamlMerge.Tests/Scenarios/When_Duplicate_ThemeResources_With_Ignored_Prefix/Input_Dictionary_1.xml

@@ -0,0 +1,7 @@
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="a1" xmlns:a1="using:ns1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<ResourceDictionary.ThemeDictionaries>
+		<ResourceDictionary x:Key="Default">
+			<a1:Thickness x:Key="FlipViewButtonBorderThemeThickness">2</a1:Thickness>
+		</ResourceDictionary>
+	</ResourceDictionary.ThemeDictionaries>
+</ResourceDictionary>

src/Uno.XamlMerge.Tests/Scenarios/When_Duplicate_ThemeResources_With_Ignored_Prefix/Input_Dictionary_2.xml

@@ -0,0 +1,7 @@
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="a2" xmlns:a2="using:ns1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<ResourceDictionary.ThemeDictionaries>
+		<ResourceDictionary x:Key="Default">
+			<a2:Thickness x:Key="FlipViewButtonBorderThemeThickness">2</a2:Thickness>
+		</ResourceDictionary>
+	</ResourceDictionary.ThemeDictionaries>
+</ResourceDictionary>

src/Uno.XamlMerge.Tests/Scenarios/When_Duplicate_ThemeResources_With_Ignored_Prefix/expected.xml

@@ -0,0 +1,10 @@
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="a1 a2" xmlns:a1="using:ns1" xmlns:a2="using:ns1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<ResourceDictionary.ThemeDictionaries>
+		<ResourceDictionary x:Key="Default">
+			<a1:Thickness x:Key="FlipViewButtonBorderThemeThickness">2</a1:Thickness>
+			<a2:Thickness x:Key="FlipViewButtonBorderThemeThickness">2</a2:Thickness>
+		</ResourceDictionary>
+	</ResourceDictionary.ThemeDictionaries>
+	<!--origin: When_Duplicate_ThemeResources_With_Ignored_Prefix\Input_Dictionary_1.xml-->
+	<!--origin: When_Duplicate_ThemeResources_With_Ignored_Prefix\Input_Dictionary_2.xml-->
+</ResourceDictionary>

src/Uno.XamlMerge.Tests/Scenarios/When_Duplicate_ThemeResources_With_Prefix/Input_Dictionary_1.xml

@@ -0,0 +1,7 @@
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:a1="using:ns1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<ResourceDictionary.ThemeDictionaries>
+		<ResourceDictionary x:Key="Default">
+			<a1:Thickness x:Key="FlipViewButtonBorderThemeThickness">2</a1:Thickness>
+		</ResourceDictionary>
+	</ResourceDictionary.ThemeDictionaries>
+</ResourceDictionary>

src/Uno.XamlMerge.Tests/Scenarios/When_Duplicate_ThemeResources_With_Prefix/Input_Dictionary_2.xml

@@ -0,0 +1,7 @@
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:a2="using:ns1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<ResourceDictionary.ThemeDictionaries>
+		<ResourceDictionary x:Key="Default">
+			<a2:Thickness x:Key="FlipViewButtonBorderThemeThickness">2</a2:Thickness>
+		</ResourceDictionary>
+	</ResourceDictionary.ThemeDictionaries>
+</ResourceDictionary>

src/Uno.XamlMerge.Tests/Scenarios/When_Duplicate_ThemeResources_With_Prefix/expected.xml

@@ -0,0 +1,9 @@
+<ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:a1="using:ns1" xmlns:a2="using:ns1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<ResourceDictionary.ThemeDictionaries>
+		<ResourceDictionary x:Key="Default">
+			<a2:Thickness x:Key="FlipViewButtonBorderThemeThickness">2</a2:Thickness>
+		</ResourceDictionary>
+	</ResourceDictionary.ThemeDictionaries>
+	<!--origin: When_Duplicate_ThemeResources_With_Prefix\Input_Dictionary_1.xml-->
+	<!--origin: When_Duplicate_ThemeResources_With_Prefix\Input_Dictionary_2.xml-->
+</ResourceDictionary>