Fix file size estimation when bundling symlinks

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:

> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018: The "GenerateBundle" task failed unexpectedly. [/build/test/test.fsproj]
> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018: System.NotSupportedException: Unable to expand length of this stream beyond its capacity. [/build/test/test.fsproj]
> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018:    at System.IO.UnmanagedMemoryStream.WriteCore(ReadOnlySpan`1 buffer) [/build/test/test.fsproj]
> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018:    at System.IO.Stream.CopyTo(Stream destination, Int32 bufferSize) [/build/test/test.fsproj]
> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018:    at Microsoft.NET.HostModel.Bundle.Bundler.AddToBundle(Stream bundle, FileStream file, FileType type) [/build/test/test.fsproj]
> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018:    at Microsoft.NET.HostModel.Bundle.Bundler.GenerateBundle(IReadOnlyList`1 fileSpecs) [/build/test/test.fsproj]
> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018:    at Microsoft.NET.Build.Tasks.GenerateBundle.ExecuteCore() [/build/test/test.fsproj]
> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018:    at Microsoft.NET.Build.Tasks.TaskBase.Execute() [/build/test/test.fsproj]
> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018:    at Microsoft.Build.BackEnd.TaskExecutionHost.Execute() [/build/test/test.fsproj]
> [...]/Microsoft.NET.Publish.targets(1132,5): error MSB4018:    at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(TaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMo

Fixes: b79c4fb

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>6.1.3</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

@@ -32,5 +32,11 @@ 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="$(SystemReflectionMetadataToolsetVersion)" Folder="lib/net462" />
+    <PackageDownloadAndReference Include="System.IO.Redist" Version="$(MicrosoftIoRedistVersion)" Folder="lib/net462" />
   </ItemGroup>
 
   <ItemGroup>