Include None/Content that has CopyToOutputDirectory!=None by default

Improve the inference so that by default we include both item types
if they have been assigned a target path by the built-in targets,
meaning that they have a `%(CopyToOutputDirectory) != None`.

Also, introduce a new `$(IncludeNoneInPackage)` value that acts as
a default (true) also for `@(None) items, making it consistent with
`@(Content)`

Fixes NuGet/Home#5105

Author: kzu

src/Build/NuGet.Build.Packaging.Tasks/NuGet.Build.Packaging.targets

@@ -30,8 +30,10 @@ Copyright (c) .NET Foundation. All rights reserved.
 
 		<!-- Infer PackageRererence elements from packages.config/project.json files in the project -->
 		<InferLegacyPackageReferences Condition="'$(InferLegacyPackageReferences)' == ''">true</InferLegacyPackageReferences>
-		<!-- Whether to include @(Content) items in the package -->
+		<!-- Whether to include @(Content) items with CopyToOutputDirectory != 'None' in the package -->
 		<IncludeContentInPackage Condition="'$(IncludeContentInPackage)' == ''">true</IncludeContentInPackage>
+		<!-- Whether to include @(None) items with CopyToOutputDirectory != 'None' in the package -->
+		<IncludeNoneInPackage Condition="'$(IncludeNoneInPackage)' == ''">true</IncludeNoneInPackage>
 		<!-- Whether to include @(BuiltProjectOutputGroupOutput), @(DocumentationProjectOutputGroupOutput) and @(SatelliteDllsProjectOutputGroupOutput) items in the package -->
 		<IncludeOutputsInPackage Condition="'$(IncludeOutputsInPackage)' == ''">true</IncludeOutputsInPackage>
 		<!-- Whether to include @(DebugSymbolsProjectOutputGroupOutput) items in the package -->
@@ -286,16 +288,16 @@ Copyright (c) .NET Foundation. All rights reserved.
 				<FrameworkSpecific>$(PrimaryOutputFrameworkSpecific)</FrameworkSpecific>
 			</PackageFile>
 
-			<!-- NOTE: Content is opt-out (must have IncludeInPackage=false to exclude) -->
+			<!-- NOTE: Content is opt-out (must have IncludeInPackage=false to exclude if IncludeContentInPackage=true) -->
 			<!-- @ContentFilesProjectOutputGroupOutput = @(ContentWithTargetPath -> '%(FullPath)') -->
 			<PackageFile Include="@(ContentWithTargetPath->'%(FullPath)')"
-									 Condition="'$(IncludeContentInPackage)' == 'true' and '%(ContentWithTargetPath.IncludeInPackage)' != 'false'">
+							   Condition="'%(ContentWithTargetPath.IncludeInPackage)' == 'true' or ('$(IncludeContentInPackage)' == 'true' and '%(ContentWithTargetPath.IncludeInPackage)' != 'false')">
 				<Kind>Content</Kind>
 			</PackageFile>
 
-			<!-- NOTE: None is opt-in (must have IncludeInPackage=true to include) -->
-			<PackageFile Include="@(_NoneWithTargetPath)"
-									 Condition="'%(_NoneWithTargetPath.IncludeInPackage)' == 'true'">
+			<!-- NOTE: None is also opt-out (must have IncludeInPackage=false to exclude if IncludeNoneInPackage=true) -->
+			<PackageFile Include="@(_NoneWithTargetPath->'%(FullPath)')"
+							   Condition="'%(_NoneWithTargetPath.IncludeInPackage)' == 'true' or ('$(IncludeNoneInPackage)' == 'true' and '%(_NoneWithTargetPath.IncludeInPackage)' != 'false')">
 				<Kind>None</Kind>
 			</PackageFile>
 

src/Build/NuGet.Build.Packaging.Tests/given_a_library_with_content.cs

@@ -60,11 +60,12 @@ public void when_library_is_packable_then_contains_content_files_in_anylang_tfm_
 		}
 
 		[Fact]
-		public void when_none_item_has_no_include_in_package_then_it_is_not_included()
+		public void when_include_none_in_package_is_false_then_inferred_none_is_not_included()
 		{
 			var result = Builder.BuildScenario(nameof(given_a_library_with_content), new
 			{
 				PackageId = "ContentPackage",
+				IncludeNoneInPackage = "false",
 			});
 
 			result.AssertSuccess(output);
@@ -75,6 +76,39 @@ public void when_none_item_has_no_include_in_package_then_it_is_not_included()
 			}));
 		}
 
+		[Fact]
+		public void when_include_none_in_package_is_false_then_explicitly_included_none_is_included()
+		{
+			var result = Builder.BuildScenario(nameof(given_a_library_with_content), new
+			{
+				PackageId = "ContentPackage",
+				IncludeNoneInPackage = "false",
+			});
+
+			result.AssertSuccess(output);
+
+			Assert.Contains(result.Items, item => item.Matches(new
+			{
+				TargetPath = "none-with-include-true.txt",
+			}));
+		}
+
+		[Fact]
+		public void when_none_item_has_no_include_in_package_then_it_is_included_by_default()
+		{
+			var result = Builder.BuildScenario(nameof(given_a_library_with_content), new
+			{
+				PackageId = "ContentPackage",
+			});
+
+			result.AssertSuccess(output);
+
+			Assert.Contains(result.Items, item => item.Matches(new
+			{
+				TargetPath = "none.txt",
+			}));
+		}
+
 		[Fact]
 		public void when_none_item_has_include_in_package_true_then_it_is_included()
 		{
@@ -139,6 +173,23 @@ public void when_content_item_has_include_in_package_true_then_it_is_included()
 			}));
 		}
 
+		[Fact]
+		public void when_include_content_in_package_is_false_then_explicitly_included_content_is_included()
+		{
+			var result = Builder.BuildScenario(nameof(given_a_library_with_content), new
+			{
+				PackageId = "ContentPackage",
+				IncludeContentInPackage = "false",
+			});
+
+			result.AssertSuccess(output);
+
+			Assert.Contains(result.Items, item => item.Matches(new
+			{
+				TargetPath = "content-with-include-true.txt",
+			}));
+		}
+
 		[Fact]
 		public void when_removing_inferred_package_file_from_content_then_content_is_not_included()
 		{