SharpZipLib issue #834 repro

CSharp · Console

/Program.cs

using System;
using System.IO;
using System.Linq;

using NUnit.Framework.Internal;

using ICSharpCode.SharpZipLib.Tar;

TarEntry symlinkEntry = new TarEntry(new TarHeader()
{
    Name = "MySymlink",
	Mode = Convert.ToInt32("774", 8),
	TypeFlag = TarHeader.LF_SYMLINK,
	ModTime = DateTime.UtcNow,
	Size = 0,
	LinkName = "MyFile",
});

Test(SymlinkWithArchiveClass, symlinkEntry);
Test(SymlinkWithStreamClass, symlinkEntry);

// BAD:
// WriteEntry() wants to append file data, which we
// don't have with symlinks. For directories (LF_DIR),
// there is an exemption. I expected one for LF_SYMLINK too.
void SymlinkWithArchiveClass(TarEntry entry) {
	
	using (var ms = new MemoryStream())
	{
		var ar = TarArchive.CreateOutputTarArchive(ms);
		ar.WriteEntry(entry, false);
		ar.Close();
	}
}

// GOOD:
void SymlinkWithStreamClass(TarEntry entry) {
	
	using var ms = new MemoryStream();
	using (var ts = new TarOutputStream(ms, System.Text.Encoding.UTF8))
	{
		ts.PutNextEntry(entry);
		ts.CloseEntry();
		ts.Close();
	}
}

#region Helpers // These are just a helpers to make the results more legible

void Test<T>(Action<T> a, T input) 
{
	// Prevent NUnit from grouping exceptions together
	using var ctx = new TestExecutionContext.IsolatedContext();
	Console.WriteLine($"Testing input \"{input}\"...\n");
	try { 
		a(input);
		Console.WriteLine("\n=> OK!");
	}
	catch (Exception x) {
		Console.WriteLine($"\n=> Failed! ({x.GetType().Name})");	
		Console.WriteLine($"\n{x.Message}");
		var trimmedStack = string.Join("\n", x.StackTrace.Split("\n").Where(l => !l.Contains("ReportFailure")));
		Console.WriteLine($"{trimmedStack}");
	}
	Console.WriteLine($"\n{new string('=', 128)}\n");
}
void Log(string message) => Console.WriteLine($"  {message}");
#endregion