Fix file size estimation when bundling symlinks (#118732)

FileInfo.Length will return the size of a symlink, rather than the file
itself. On a source-built dotnet SDK, a trivial test project will bundle
files like:

packs/Microsoft.NETCore.App.Runtime.linux-x64/10.0.0-preview.7.25380.108/runtimes/linux-x64/lib/net10.0/Microsoft.CSharp.dll

Which is a symlink to:

../../../../../../../shared/Microsoft.NETCore.App/10.0.0-preview.7.25380.108/Microsoft.CSharp.dll

This can result in failures when trying to bundle

Fixes: b79c4fb

Co-authored-by: Jackson Schuster <36744439+jtschuster@users.noreply.github.com>

Author: corngood

eng/Versions.props

@@ -97,6 +97,7 @@
     <SystemThreadingAccessControlVersion>7.0.0</SystemThreadingAccessControlVersion>
     <!-- Keep toolset versions in sync with dotnet/msbuild and dotnet/sdk -->
     <MicrosoftBclAsyncInterfacesToolsetVersion>8.0.0</MicrosoftBclAsyncInterfacesToolsetVersion>
+    <MicrosoftIoRedistToolsetVersion>6.0.1</MicrosoftIoRedistToolsetVersion>
     <SystemBuffersToolsetVersion>4.5.1</SystemBuffersToolsetVersion>
     <SystemCollectionsImmutableToolsetVersion>8.0.0</SystemCollectionsImmutableToolsetVersion>
     <SystemMemoryToolsetVersion>4.5.5</SystemMemoryToolsetVersion>

src/installer/managed/Microsoft.NET.HostModel/AppHost/HostWriter.cs

@@ -124,7 +124,7 @@ void RewriteAppHost(MemoryMappedFile mappedFile, MemoryMappedViewAccessor access
                     if (File.Exists(appHostDestinationFilePath))
                         File.Delete(appHostDestinationFilePath);
 
-                    long appHostSourceLength = new FileInfo(appHostSourceFilePath).Length;
+                    long appHostSourceLength = HostModelUtils.GetFileLength(appHostSourceFilePath);
                     string destinationFileName = Path.GetFileName(appHostDestinationFilePath);
                     // Memory-mapped files cannot be resized, so calculate
                     // the maximum length of the destination file upfront.

src/installer/managed/Microsoft.NET.HostModel/Bundle/Bundler.cs

@@ -293,7 +293,7 @@ public string GenerateBundle(IReadOnlyList<FileSpec> fileSpecs)
             // We will memory map a larger file than needed, but we'll take that trade-off.
             foreach (var (spec, type) in relativePathToSpec)
             {
-                bundledFilesSize += new FileInfo(spec.SourcePath).Length;
+                bundledFilesSize += HostModelUtils.GetFileLength(spec.SourcePath);
                 if (type == FileType.Assembly)
                 {
                     // Alignment could be as much as AssemblyAlignment - 1 bytes.
@@ -314,7 +314,7 @@ public string GenerateBundle(IReadOnlyList<FileSpec> fileSpecs)
             {
                 Directory.CreateDirectory(destinationDirectory);
             }
-            var hostLength = new FileInfo(hostSource).Length;
+            var hostLength = HostModelUtils.GetFileLength(hostSource);
             var bundleManifestLength = Manifest.GetManifestLength(BundleManifest.BundleMajorVersion, relativePathToSpec.Select(x => x.Spec.BundleRelativePath));
             long bundleTotalSize = hostLength + bundledFilesSize + bundleManifestLength;
             if (_target.IsOSX && _macosCodesign)

src/installer/managed/Microsoft.NET.HostModel/HostModelUtils.cs

@@ -2,9 +2,14 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Diagnostics;
+#if NETFRAMEWORK
+using Microsoft.IO;
+#else
 using System.IO;
+#endif
 using System.Runtime.InteropServices;
 
+
 namespace Microsoft.NET.HostModel
 {
     internal static class HostModelUtils
@@ -32,5 +37,11 @@ public static (int ExitCode, string StdErr) RunCodesign(string args, string appH
                 return (p.ExitCode, p.StandardError.ReadToEnd());
             }
         }
+
+        public static long GetFileLength(string path)
+        {
+            var info = new FileInfo(path);
+            return ((FileInfo)info.ResolveLinkTarget(true) ?? info).Length;
+        }
     }
 }

src/installer/managed/Microsoft.NET.HostModel/Microsoft.NET.HostModel.csproj

@@ -24,6 +24,7 @@
     <PackageDownloadAndReference Include="System.Memory" Version="$(SystemMemoryToolsetVersion)" Folder="lib/net461" />
     <PackageDownloadAndReference Include="System.Text.Json" Version="$(SystemTextJsonToolsetVersion)" Folder="lib/net462" />
     <PackageDownloadAndReference Include="System.Reflection.Metadata" Version="$(SystemReflectionMetadataToolsetVersion)" Folder="lib/net462" />
+    <PackageDownloadAndReference Include="Microsoft.IO.Redist" Version="$(MicrosoftIoRedistToolsetVersion)" Folder="lib/net472" />
   </ItemGroup>
 
   <ItemGroup>

src/installer/tests/Microsoft.NET.HostModel.Tests/Bundle/BundlerConsistencyTests.cs

@@ -98,6 +98,24 @@ public void ExactDuplicateEntries()
             bundler.BundleManifest.Files.Where(entry => entry.RelativePath.Equals("rel/system.repeat.dll")).Single().Type.Should().Be(FileType.Assembly);
         }
 
+        [Fact]
+        public void ResolveLinkTargets()
+        {
+            string appPath = Path.Combine(
+                Path.GetDirectoryName(sharedTestState.App.AppDll),
+                Path.GetFileNameWithoutExtension(sharedTestState.App.AppDll)
+                    + ".link" + Path.GetExtension(sharedTestState.App.AppDll));
+            File.CreateSymbolicLink(appPath, sharedTestState.App.AppDll);
+            // File specification with duplicate entries with matching source paths
+            var fileSpecs = new FileSpec[]
+            {
+                new FileSpec(Binaries.AppHost.FilePath, BundlerHostName),
+                new FileSpec(appPath, "rel/app.repeat.dll")
+            };
+            Bundler bundler = CreateBundlerInstance();
+            bundler.GenerateBundle(fileSpecs);
+        }
+
         [Fact]
         public void DuplicateBundleRelativePath_Fails()
         {