From dfb96a413e6e18c866ef4199b7646fc698e1dc38 Mon Sep 17 00:00:00 2001
From: Stephane Delcroix <stephane@delcroix.org>
Date: Thu, 18 Jun 2020 23:09:02 +0200
Subject: [PATCH] [X] find xmlns in Core at design time

- fixes #11101
---
 .nuspec/Xamarin.Forms.targets                        |  3 +--
 Xamarin.Forms.Build.Tasks/XamlGenerator.cs           | 12 ++++++------
 Xamarin.Forms.Xaml.UnitTests/MSBuild/MSBuildTests.cs |  5 -----
 3 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/.nuspec/Xamarin.Forms.targets b/.nuspec/Xamarin.Forms.targets
index cd9f89fce33..2a3e666293e 100644
--- a/.nuspec/Xamarin.Forms.targets
+++ b/.nuspec/Xamarin.Forms.targets
@@ -84,8 +84,7 @@
 		Inputs="@(_XamlGInputs)"
 		Outputs="@(_XamlGOutputs)">
 		<PropertyGroup>
-			<ReferencedAssemblies Condition="'$(_ReferencedAssemblies)'==''">@(ReferencePath)</ReferencedAssemblies>
-      <ReferencedAssemblies Condition="'$(_ReferencedAssemblies)'!=''">$(_ReferencedAssemblies)</ReferencedAssemblies>
+			<ReferencedAssemblies>@(ReferencePath)</ReferencedAssemblies>
 		</PropertyGroup>
 		<XamlGTask
 			XamlFiles="@(_XamlGInputs)"
diff --git a/Xamarin.Forms.Build.Tasks/XamlGenerator.cs b/Xamarin.Forms.Build.Tasks/XamlGenerator.cs
index 049abbff7f7..69edadcc461 100644
--- a/Xamarin.Forms.Build.Tasks/XamlGenerator.cs
+++ b/Xamarin.Forms.Build.Tasks/XamlGenerator.cs
@@ -383,10 +383,10 @@ void GatherXmlnsDefinitionAttributes()
 			_xmlnsDefinitions = new List<XmlnsDefinitionAttribute>();
 			_xmlnsModules = new Dictionary<string, ModuleDefinition>();
 
-			if (string.IsNullOrEmpty(References))
-				return;
-
-			string[] paths = References.Split(';').Distinct().ToArray();
+			var paths = References?.Split(';').Distinct().ToList() ?? new List<string>();
+			//Load xmlnsdef from Core and Xaml
+			paths.Add(typeof(Label).Assembly.Location);
+			paths.Add(typeof(Xamarin.Forms.Xaml.Extensions).Assembly.Location);
 
 			foreach (var path in paths) {
 				string asmName = IOPath.GetFileName(path);
@@ -430,9 +430,9 @@ CodeTypeReference GetCustomNamespaceUrlType(XmlType xmlType)
 				null,
 				(typeInfo) =>
 				{
-					ModuleDefinition module = null;
-					if (typeInfo.AssemblyName == null || !_xmlnsModules.TryGetValue(typeInfo.AssemblyName, out module))
+					if (typeInfo.AssemblyName == null || !_xmlnsModules.TryGetValue(typeInfo.AssemblyName, out ModuleDefinition module))
 						return null;
+
 					string typeName = typeInfo.TypeName.Replace('+', '/'); //Nested types
 					string fullName = $"{typeInfo.ClrNamespace}.{typeInfo.TypeName}";
 					return module.Types.Where(t => t.FullName == fullName).FirstOrDefault();
diff --git a/Xamarin.Forms.Xaml.UnitTests/MSBuild/MSBuildTests.cs b/Xamarin.Forms.Xaml.UnitTests/MSBuild/MSBuildTests.cs
index fd3c1847ecb..cfff0eceaf7 100644
--- a/Xamarin.Forms.Xaml.UnitTests/MSBuild/MSBuildTests.cs
+++ b/Xamarin.Forms.Xaml.UnitTests/MSBuild/MSBuildTests.cs
@@ -140,11 +140,6 @@ XElement NewProject (bool sdkStyle)
 				propertyGroup.Add (NewElement ("TargetFrameworkVersion").WithValue ("v4.7"));
 				propertyGroup.Add(NewElement("RootNamespace").WithValue("test"));
 			}
-			var refpath = string.Join(";",
-				IOPath.Combine("..", "..", "Xamarin.Forms.Core.dll"),
-				IOPath.Combine("..", "..", "Xamarin.Forms.Xaml.dll"));
-			propertyGroup.Add(NewElement("_ReferencedAssemblies").WithValue($"{refpath}"));
-
 			propertyGroup.Add(NewElement("_XFBuildTasksLocation").WithValue($"{testDirectory}\\"));