Fix workload advertising manifest extraction with WiX v4+ built MSIs

src/Cli/dotnet/Commands/Workload/Install/WindowsMsiManifestInstaller.cs

@@ -129,14 +129,7 @@ public async Task ExtractManifestAsync(string nupkgPath, string targetPath)
                     }
                 }
 
-                var manifestsFolder = Path.Combine(msiExtractionPath, "dotnet", "sdk-manifests");
-
-                string? manifestFolder = null;
-                string? manifestsFeatureBandFolder = Directory.GetDirectories(manifestsFolder).SingleOrDefault();
-                if (manifestsFeatureBandFolder != null)
-                {
-                    manifestFolder = Directory.GetDirectories(manifestsFeatureBandFolder).SingleOrDefault();
-                }
+                string? manifestFolder = FindExtractedManifestFolder(msiExtractionPath);
 
                 if (manifestFolder == null)
                 {
@@ -155,6 +148,42 @@ public async Task ExtractManifestAsync(string nupkgPath, string targetPath)
         }
     }
 
+    /// <summary>
+    ///  Locates the extracted manifest directory in the layout produced by the administrative install of a
+    ///  manifest or workload set MSI.
+    ///
+    ///  <para>
+    ///  The MSI lays its content down under <c>&lt;Program Files&gt;\dotnet\sdk-manifests\&lt;feature band&gt;\...</c>,
+    ///  but the name of the Program Files directory in the administrative image depends on the WiX version that
+    ///  built the MSI: WiX v3 collapsed it into the target directory (<c>&lt;target&gt;\dotnet\sdk-manifests</c>),
+    ///  while WiX v4+ emits a named directory for it (for example <c>&lt;target&gt;\PFiles64\dotnet\sdk-manifests</c>).
+    ///  Search for the <c>sdk-manifests</c> directory instead of assuming a fixed depth so that both layouts work.
+    ///  </para>
+    /// </summary>
+    /// <param name="msiExtractionPath">The directory the MSI was administratively installed to.</param>
+    /// <returns>The extracted manifest directory, or <see langword="null"/> if it could not be located.</returns>
+    internal static string? FindExtractedManifestFolder(string msiExtractionPath)
+    {
+        if (!Directory.Exists(msiExtractionPath))
+        {
+            return null;
+        }
+
+        string? manifestsFolder = Directory.EnumerateDirectories(msiExtractionPath, "sdk-manifests", SearchOption.AllDirectories).FirstOrDefault();
+        if (manifestsFolder == null)
+        {
+            return null;
+        }
+
+        string? manifestsFeatureBandFolder = Directory.GetDirectories(manifestsFolder).SingleOrDefault();
+        if (manifestsFeatureBandFolder == null)
+        {
+            return null;
+        }
+
+        return Directory.GetDirectories(manifestsFeatureBandFolder).SingleOrDefault();
+    }
+
     /// <summary>
     ///  Equivalent to <see cref="MsiInstallerBase.GetMsiLogNameForAdminInstall(string)"/>.
     /// </summary>

test/dotnet.Tests/CommandTests/Workload/Install/GivenAWindowsMsiManifestInstaller.cs

@@ -39,4 +39,36 @@ public void GetManifestPackageIdReturnsTheArchitectureQualifiedManifestPackageId
         packageId.ToString().Should().Be(
             $"{manifestId}.Manifest-{featureBand}.Msi.{RuntimeInformation.ProcessArchitecture}".ToLowerInvariant());
     }
+
+    // MSIs built with WiX v3 collapse the Program Files directory into the administrative install target.
+    [TestMethod]
+    public void FindExtractedManifestFolderLocatesTheManifestInTheWiXV3AdminInstallLayout()
+    {
+        var testDirectory = TestAssetsManager.CreateTestDirectory().Path;
+        var expected = Path.Combine(testDirectory, "dotnet", "sdk-manifests", "6.0.100", "test.manifest");
+        Directory.CreateDirectory(expected);
+
+        WindowsMsiManifestInstaller.FindExtractedManifestFolder(testDirectory).Should().Be(expected);
+    }
+
+    // MSIs built with WiX v4 and newer emit a named directory for Program Files in the administrative image.
+    [TestMethod]
+    public void FindExtractedManifestFolderLocatesTheManifestInTheWiXV4AdminInstallLayout()
+    {
+        var testDirectory = TestAssetsManager.CreateTestDirectory().Path;
+        var expected = Path.Combine(testDirectory, "PFiles64", "dotnet", "sdk-manifests", "6.0.100", "workloadsets");
+        Directory.CreateDirectory(expected);
+
+        WindowsMsiManifestInstaller.FindExtractedManifestFolder(testDirectory).Should().Be(expected);
+    }
+
+    [TestMethod]
+    public void FindExtractedManifestFolderReturnsNullWhenThereIsNoManifest()
+    {
+        var testDirectory = TestAssetsManager.CreateTestDirectory().Path;
+        Directory.CreateDirectory(Path.Combine(testDirectory, "PFiles64", "dotnet"));
+
+        WindowsMsiManifestInstaller.FindExtractedManifestFolder(testDirectory).Should().BeNull();
+        WindowsMsiManifestInstaller.FindExtractedManifestFolder(Path.Combine(testDirectory, "does-not-exist")).Should().BeNull();
+    }
 }