Allow Implicit RID Opt Out + Don't Infer RID for non EXE Type Projects

src/Assets/TestProjects/AppWithLibrarySDKStyleThatPublishesSingleFile/Program.cs

@@ -0,0 +1,8 @@
+namespace newc;
+
+static class Program
+{
+    static void Main()
+    {
+    }    
+}

src/Assets/TestProjects/AppWithLibrarySDKStyleThatPublishesSingleFile/lib/Class1.cs

@@ -0,0 +1,5 @@
+namespace lib;
+public class Class1
+{
+
+}

src/Assets/TestProjects/AppWithLibrarySDKStyleThatPublishesSingleFile/lib/lib.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <PublishSingleFile>true</PublishSingleFile>
+  </PropertyGroup>
+
+</Project>

src/Assets/TestProjects/AppWithLibrarySDKStyleThatPublishesSingleFile/newc.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net7.0-windows</TargetFramework>
+    <Nullable>enable</Nullable>
+    <UseWindowsForms>true</UseWindowsForms>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <PublishSingleFile>true</PublishSingleFile>
+    <RuntimeIdentifier>win-x86</RuntimeIdentifier>
+  </PropertyGroup>
+
+  <ItemGroup>
+      <ProjectReference Include="lib\lib.csproj" />
+  </ItemGroup>
+
+</Project>

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.RuntimeIdentifierInference.targets

@@ -61,17 +61,21 @@ Copyright (c) .NET Foundation. All rights reserved.
     <RuntimeIdentifier Condition="'$(PlatformTarget)' == 'x86' or '$(PlatformTarget)' == ''">win7-x86</RuntimeIdentifier>
   </PropertyGroup>
 
-  <PropertyGroup Condition="'$(UseCurrentRuntimeIdentifier)' == 'true' or
-                 (
+  <PropertyGroup Condition="'$(UseCurrentRuntimeIdentifier)' == ''">
+    <UseCurrentRuntimeIdentifier Condition="
                  '$(RuntimeIdentifier)' == '' and
                  '$(RuntimeIdentifiers)' == '' and
-                   (
-                   '$(SelfContained)' == 'true' or
-                   '$(PublishReadyToRun)' == 'true' or
-                   '$(PublishSingleFile)' == 'true' or
-                   '$(PublishAot)' == 'true'
-                   )
-                 )">
+                 '$(_IsExecutable)' == 'true' and '$(IsTestProject)' != 'true' and
+                 '$(IsRidAgnostic)' != 'true' and
+                  (
+                    '$(SelfContained)' == 'true' or
+                    '$(PublishReadyToRun)' == 'true' or
+                    '$(PublishSingleFile)' == 'true' or
+                    '$(PublishAot)' == 'true'
+                  )">true</UseCurrentRuntimeIdentifier>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(UseCurrentRuntimeIdentifier)' == 'true'">
     <RuntimeIdentifier>$(NETCoreSdkPortableRuntimeIdentifier)</RuntimeIdentifier>
   </PropertyGroup>
 

src/Tests/Microsoft.NET.Publish.Tests/GivenThatWeWantToPublishASingleFileLibrary.cs

@@ -0,0 +1,44 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.IO;
+using FluentAssertions;
+using Microsoft.NET.TestFramework;
+using Microsoft.NET.TestFramework.Assertions;
+using Microsoft.NET.TestFramework.Commands;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Microsoft.NET.Publish.Tests
+{
+    public class GivenThatWeWantToPublishASingleFileLibrary : SdkTest
+    {
+        public GivenThatWeWantToPublishASingleFileLibrary(ITestOutputHelper log) : base(log)
+        {
+        }
+
+        [WindowsOnlyFact]
+        // Tests regression on https://github.com/dotnet/sdk/pull/28484
+        public void ItPublishesSuccessfullyWithRIDAndPublishSingleFileLibrary()
+        {
+            var targetFramework = ToolsetInfo.CurrentTargetFramework;
+            var testAsset = _testAssetsManager
+                     .CopyTestAsset("AppWithLibrarySDKStyleThatPublishesSingleFile")
+                     .WithTargetFramework(targetFramework)
+                     .WithSource();
+
+            var publishCommand = new PublishCommand(testAsset);
+            publishCommand.Execute()
+                    .Should()
+                    .Pass();
+
+            // It would be better if we could somehow check the library binlog or something for a RID instead.
+            var exeFolder = publishCommand.GetOutputDirectory(targetFramework: targetFramework);
+            // Parent: RID, then TFM, then Debug, then bin, then the test folder
+            var ridlessLibraryDllPath = Path.Combine(exeFolder.Parent.Parent.Parent.Parent.FullName, "lib", "bin", "Debug", targetFramework, "lib.dll");
+            Assert.True(File.Exists(ridlessLibraryDllPath));
+        }
+
+    }
+
+}

src/Tests/Microsoft.NET.Publish.Tests/RuntimeIdentifiersTests.cs

@@ -193,6 +193,30 @@ public void PublishWithRuntimeIdentifier(bool publishNoBuild)
             }
         }
 
+        [Fact]
+        public void ImplicitRuntimeIdentifierOptOutCorrecltyOptsOut()
+        {
+            var targetFramework = ToolsetInfo.CurrentTargetFramework;
+            var runtimeIdentifier = EnvironmentInfo.GetCompatibleRid(targetFramework);
+            var testProject = new TestProject()
+            {
+                IsExe = true,
+                TargetFrameworks = targetFramework
+            };
+            testProject.AdditionalProperties["SelfContained"] = "true";
+            testProject.AdditionalProperties["UseCurrentRuntimeIdentifier"] = "false";
+
+            var testAsset = _testAssetsManager.CreateTestProject(testProject);
+
+            var publishCommand = new PublishCommand(testAsset);
+            publishCommand
+                .Execute()
+                .Should()
+                .Fail()
+                .And
+                .HaveStdOutContaining("NETSDK1191");
+        }
+
         [Fact]
         public void DuplicateRuntimeIdentifiers()
         {