[release/11.0.1xx-preview1] Source code updates from dotnet/msbuild

src/msbuild/src/Build.UnitTests/BackEnd/AssemblyLoadContextTestTasks.cs

@@ -3,11 +3,69 @@
 
 using Microsoft.Build.Framework;
 using Microsoft.Build.Utilities;
+using System;
+using System.Reflection;
 
 #nullable disable
 
 namespace AssemblyLoadContextTest
 {
+    /// <summary>
+    /// Task that validates assembly version roll-forward behavior.
+    /// Tests that MSBuildLoadContext accepts newer assembly versions when older versions are requested.
+    /// </summary>
+    public class ValidateAssemblyVersionRollForward : Task
+    {
+        /// <summary>
+        /// The name of the assembly to check (e.g., "System.Collections.Immutable")
+        /// </summary>
+        [Required]
+        public string AssemblyName { get; set; }
+
+        /// <summary>
+        /// The minimum expected version (e.g., "1.0.0.0")
+        /// </summary>
+        [Required]
+        public string MinimumVersion { get; set; }
+
+        public override bool Execute()
+        {
+            try
+            {
+                // Try to load the assembly by name with minimum version
+                var minimumVersion = Version.Parse(MinimumVersion);
+                var assemblyName = new AssemblyName(AssemblyName)
+                {
+                    Version = minimumVersion
+                };
+
+                // This will trigger MSBuildLoadContext.Load which should accept newer versions
+                var assembly = Assembly.Load(assemblyName);
+                var loadedVersion = assembly.GetName().Version;
+
+                Log.LogMessage(MessageImportance.High,
+                    $"Requested {AssemblyName} version {minimumVersion}, loaded version {loadedVersion}");
+
+                // Verify that we got a version >= minimum
+                if (loadedVersion < minimumVersion)
+                {
+                    Log.LogError(
+                        $"Assembly version roll-forward failed: requested {minimumVersion}, but loaded {loadedVersion} which is older");
+                    return false;
+                }
+
+                Log.LogMessage(MessageImportance.High,
+                    $"Assembly version roll-forward succeeded: loaded version {loadedVersion} >= requested {minimumVersion}");
+                return true;
+            }
+            catch (Exception ex)
+            {
+                Log.LogErrorFromException(ex, showStackTrace: true);
+                return false;
+            }
+        }
+    }
+
     public class RegisterObject : Task
     {
         internal const string CacheKey = "RegressionForMSBuild#5080";

src/msbuild/src/Build.UnitTests/BackEnd/TaskBuilder_Tests.cs

@@ -662,6 +662,33 @@ public void SameAssemblyFromDifferentRelativePathsSharesAssemblyLoadContext()
             logger.AssertLogDoesntContain("MSB4018");
         }
 
+#if FEATURE_ASSEMBLYLOADCONTEXT
+        /// <summary>
+        /// Regression test for https://github.com/dotnet/msbuild/issues/12370
+        /// Verifies that MSBuildLoadContext accepts newer assembly versions when older versions are requested (version roll-forward).
+        /// </summary>
+        [Fact]
+        public void MSBuildLoadContext_AcceptsNewerAssemblyVersions()
+        {
+            string realTaskPath = Assembly.GetExecutingAssembly().Location;
+
+            // Use System.Collections.Immutable as test assembly - it's available in modern .NET runtime
+            // Request an older version (1.0.0.0) which should roll forward to whatever version is available
+            string projectContents = @"<Project ToolsVersion=`msbuilddefaulttoolsversion` xmlns=`msbuildnamespace`>
+  <UsingTask TaskName=`ValidateAssemblyVersionRollForward` AssemblyFile=`" + realTaskPath + @"` />
+
+  <Target Name=`Build`>
+    <ValidateAssemblyVersionRollForward AssemblyName=`System.Collections.Immutable` MinimumVersion=`1.0.0.0` />
+  </Target>
+</Project>";
+
+            MockLogger logger = ObjectModelHelpers.BuildProjectExpectSuccess(projectContents, _testOutput);
+
+            // Verify that the task logged success message
+            logger.AssertLogContains("Assembly version roll-forward succeeded");
+        }
+#endif
+
 
 #if FEATURE_CODETASKFACTORY
         /// <summary>

src/msbuild/src/Build.UnitTests/BackEnd/TaskEnvironment_Tests.cs

@@ -384,54 +384,5 @@ public void TaskEnvironment_GetAbsolutePath_WithInvalidPathChars_ShouldNotThrow(
                 DisposeTaskEnvironment(taskEnvironment);
             }
         }
-
-        [Theory]
-        [MemberData(nameof(EnvironmentTypes))]
-        public void TaskEnvironment_GetAbsolutePath_WithEmptyPath_ReturnsProjectDirectory(string environmentType)
-        {
-            var taskEnvironment = CreateTaskEnvironment(environmentType);
-
-            // Empty path should absolutize to project directory (Path.Combine behavior)
-            var absolutePath = taskEnvironment.GetAbsolutePath(string.Empty);
-
-            absolutePath.Value.ShouldBe(taskEnvironment.ProjectDirectory.Value);
-            absolutePath.OriginalValue.ShouldBe(string.Empty);
-        }
-
-        [Theory]
-        [MemberData(nameof(EnvironmentTypes))]
-        public void TaskEnvironment_GetAbsolutePath_WithNullPath_WhenWave18_4Disabled_ReturnsNullPath(string environmentType)
-        {
-            using TestEnvironment testEnv = TestEnvironment.Create();
-            ChangeWaves.ResetStateForTests();
-            testEnv.SetEnvironmentVariable("MSBUILDDISABLEFEATURESFROMVERSION", ChangeWaves.Wave18_4.ToString());
-            BuildEnvironmentHelper.ResetInstance_ForUnitTestsOnly();
-
-            var taskEnvironment = CreateTaskEnvironment(environmentType);
-
-            // When Wave18_4 is disabled, null path returns as-is
-            var absolutePath = taskEnvironment.GetAbsolutePath(null!);
-
-            absolutePath.Value.ShouldBeNull();
-            absolutePath.OriginalValue.ShouldBeNull();
-
-            ChangeWaves.ResetStateForTests();
-        }
-
-        [Theory]
-        [MemberData(nameof(EnvironmentTypes))]
-        public void TaskEnvironment_GetAbsolutePath_WithNullPath_WhenWave18_4Enabled_Throws(string environmentType)
-        {
-            using TestEnvironment testEnv = TestEnvironment.Create();
-            ChangeWaves.ResetStateForTests();
-            BuildEnvironmentHelper.ResetInstance_ForUnitTestsOnly();
-
-            var taskEnvironment = CreateTaskEnvironment(environmentType);
-
-            // When Wave18_4 is enabled, null path should throw
-            Should.Throw<ArgumentNullException>(() => taskEnvironment.GetAbsolutePath(null!));
-
-            ChangeWaves.ResetStateForTests();
-        }
     }
 }

src/msbuild/src/Build/BackEnd/Shared/BuildRequestConfiguration.cs

@@ -301,7 +301,7 @@ public bool IsTraversal
             {
                 if (!_isTraversalProject.HasValue)
                 {
-#if NET471_OR_GREATER
+#if FEATURE_MSIOREDIST
                     if (MemoryExtensions.Equals(Microsoft.IO.Path.GetFileName(ProjectFullPath.AsSpan()), "dirs.proj".AsSpan(), StringComparison.OrdinalIgnoreCase))
 #else
                     if (MemoryExtensions.Equals(Path.GetFileName(ProjectFullPath.AsSpan()), "dirs.proj", StringComparison.OrdinalIgnoreCase))

src/msbuild/src/Build/BackEnd/TaskExecutionHost/MultiProcessTaskEnvironmentDriver.cs

@@ -40,13 +40,7 @@ public AbsolutePath ProjectDirectory
         /// <inheritdoc/>
         public AbsolutePath GetAbsolutePath(string path)
         {
-            // Opt-out for null path when Wave18_4 is disabled - return null as-is.
-            if (!ChangeWaves.AreFeaturesEnabled(ChangeWaves.Wave18_4) && path is null)
-            {
-                return new AbsolutePath(path!, path!, ignoreRootedCheck: true);
-            }
-
-            return new AbsolutePath(path, basePath: ProjectDirectory);
+            return new AbsolutePath(path, ProjectDirectory);
         }
 
         /// <inheritdoc/>

src/msbuild/src/Build/BackEnd/TaskExecutionHost/MultiThreadedTaskEnvironmentDriver.cs

@@ -71,12 +71,6 @@ public AbsolutePath ProjectDirectory
         /// <inheritdoc/>
         public AbsolutePath GetAbsolutePath(string path)
         {
-            // Opt-out for null path when Wave18_4 is disabled - return null as-is.
-            if (!ChangeWaves.AreFeaturesEnabled(ChangeWaves.Wave18_4) && path is null)
-            {
-                return new AbsolutePath(path!, path!, ignoreRootedCheck: true);
-            }
-
             return new AbsolutePath(path, ProjectDirectory);
         }
 

src/msbuild/src/Build/BuildCheck/Checks/DoubleWritesCheck.cs

@@ -3,15 +3,14 @@
 
 using System;
 using System.Collections.Generic;
-#if !FEATURE_MSIOREDIST
-using System.IO;
-#endif
 using System.Linq;
 using Microsoft.Build.Shared;
 using static Microsoft.Build.Experimental.BuildCheck.TaskInvocationCheckData;
 
 #if FEATURE_MSIOREDIST
 using Path = Microsoft.IO.Path;
+#else
+using System.IO;
 #endif
 
 namespace Microsoft.Build.Experimental.BuildCheck.Checks;

src/msbuild/src/Build/BuildCheck/Checks/ExecCliBuildCheck.cs

@@ -3,13 +3,12 @@
 
 using System;
 using System.Collections.Generic;
-#if !FEATURE_MSIOREDIST
-using System.IO;
-#endif
 using Microsoft.Build.Shared;
 
 #if FEATURE_MSIOREDIST
 using Path = Microsoft.IO.Path;
+#else
+using System.IO;
 #endif
 
 namespace Microsoft.Build.Experimental.BuildCheck.Checks;

src/msbuild/src/Build/Evaluation/Expander.cs

@@ -7,11 +7,7 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
-#if NET
 using System.IO;
-#else
-using Microsoft.IO;
-#endif
 using System.Linq;
 using System.Reflection;
 using System.Runtime.CompilerServices;
@@ -34,6 +30,11 @@
 using TaskItem = Microsoft.Build.Execution.ProjectItemInstance.TaskItem;
 using TaskItemFactory = Microsoft.Build.Execution.ProjectItemInstance.TaskItem.TaskItemFactory;
 
+#if FEATURE_MSIOREDIST
+using Directory = Microsoft.IO.Directory;
+using Path = Microsoft.IO.Path;
+#endif
+
 #nullable disable
 
 namespace Microsoft.Build.Evaluation

src/msbuild/src/Build/Evaluation/Expander/ArgumentParser.cs

@@ -4,7 +4,7 @@
 using System;
 using System.Globalization;
 
-#if NETFRAMEWORK
+#if FEATURE_MSIOREDIST
 using Microsoft.IO;
 #endif
 

src/msbuild/src/Build/Instance/ProjectItemInstance.cs

@@ -743,7 +743,8 @@ private void CommonConstructor(
             if (itemDefinitions == null || !useItemDefinitionsWithoutModification)
             {
                 // TaskItems don't have an item type. So for their benefit, we have to lookup and add the regular item definition.
-                inheritedItemDefinitions = (itemDefinitions == null) ? null : new List<ProjectItemDefinitionInstance>(itemDefinitions);
+                inheritedItemDefinitions = (itemDefinitions == null) ? null : new List<ProjectItemDefinitionInstance>(itemDefinitions.Count + 1);
+                ((List<ProjectItemDefinitionInstance>)inheritedItemDefinitions)?.AddRange(itemDefinitions);
 
                 ProjectItemDefinitionInstance itemDefinition;
                 if (projectToUse.ItemDefinitions.TryGetValue(itemTypeToUse, out itemDefinition))

src/msbuild/src/Build/Instance/TaskFactories/AssemblyTaskFactory.cs

@@ -11,8 +11,9 @@
 using Microsoft.Build.BackEnd.Components.RequestBuilder;
 using Microsoft.Build.Framework;
 using Microsoft.Build.Shared;
-#if NETFRAMEWORK
-using Microsoft.IO;
+
+#if FEATURE_MSIOREDIST
+using Path = Microsoft.IO.Path;
 #else
 using System.IO;
 #endif

src/msbuild/src/Build/Logging/TerminalLogger/TerminalLogger.cs

@@ -16,8 +16,8 @@
 using System.Buffers;
 #endif
 
-#if NETFRAMEWORK
-using Microsoft.IO;
+#if FEATURE_MSIOREDIST
+using Path = Microsoft.IO.Path;
 #else
 using System.IO;
 #endif

src/msbuild/src/Build/Utilities/Utilities.cs

@@ -5,11 +5,6 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics;
-#if NET
-using System.IO;
-#else
-using Microsoft.IO;
-#endif
 using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
@@ -22,6 +17,12 @@
 using Toolset = Microsoft.Build.Evaluation.Toolset;
 using XmlElementWithLocation = Microsoft.Build.Construction.XmlElementWithLocation;
 
+#if FEATURE_MSIOREDIST
+using Path = Microsoft.IO.Path;
+#else
+using System.IO;
+#endif
+
 #nullable disable
 
 namespace Microsoft.Build.Internal

src/msbuild/src/Framework.UnitTests/AbsolutePath_Tests.cs

@@ -1,15 +1,23 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.IO;
 using Microsoft.Build.Framework;
+using Microsoft.Build.Shared;
 using Shouldly;
 using Xunit;
 
 namespace Microsoft.Build.UnitTests
 {
     public class AbsolutePath_Tests
     {
+        private static AbsolutePath GetTestBasePath()
+        {
+            string baseDirectory = Path.Combine(Path.GetTempPath(), "abspath_test_base");
+            return new AbsolutePath(baseDirectory, ignoreRootedCheck: false);
+        }
+
         private static void ValidatePathAcceptance(string path, bool shouldBeAccepted)
         {
             if (shouldBeAccepted)
@@ -36,11 +44,27 @@ public void AbsolutePath_FromAbsolutePath_ShouldPreservePath()
             Path.IsPathRooted(absolutePath.Value).ShouldBeTrue();
         }
 
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        public void AbsolutePath_NullOrEmpty_ShouldThrow(string? path)
+        {
+            Should.Throw<ArgumentException>(() => new AbsolutePath(path!));
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        public void AbsolutePath_NullOrEmptyWithBasePath_ShouldThrow(string? path)
+        {
+            var basePath = GetTestBasePath();
+            Should.Throw<ArgumentException>(() => new AbsolutePath(path!, basePath));
+        }
+
         [Theory]
         [InlineData("subfolder")]
         [InlineData("deep/nested/path")]
         [InlineData(".")]
-        [InlineData("")]
         [InlineData("..")]
         public void AbsolutePath_FromRelativePath_ShouldResolveAgainstBase(string relativePath)
         {