Fix bug compressing directories with deeply nested/recursive symlinks (#197)

src/lib-csharp/Compression/EasyZip.cs

@@ -61,8 +61,10 @@ namespace Velopack.Compression
                     if (!Utility.IsFileInDirectory(absolute, destinationDirectoryName)) {
                         throw new IOException("IO_SymlinkTargetNotInDirectory");
                     }
+
                     SymbolicLink.Create(fileDestinationPath, absolute, true, true);
                 }
+
                 return;
             }
 
@@ -94,6 +96,7 @@ namespace Velopack.Compression
                 await DeterministicCreateFromDirectoryAsync(directoryToCompress, outputFile, compressionLevel, progress, cancelToken).ConfigureAwait(false);
             } catch {
                 try { File.Delete(outputFile); } catch { }
+
                 throw;
             }
         }
@@ -101,7 +104,8 @@ namespace Velopack.Compression
         private static char s_pathSeperator = '/';
         public static readonly DateTime ZipFormatMinDate = new DateTime(1980, 1, 1, 0, 0, 0, DateTimeKind.Utc);
 
-        private static async Task DeterministicCreateFromDirectoryAsync(string sourceDirectoryName, string destinationArchiveFileName, CompressionLevel compressionLevel,
+        private static async Task DeterministicCreateFromDirectoryAsync(string sourceDirectoryName, string destinationArchiveFileName,
+            CompressionLevel compressionLevel,
             Action<int> progress, CancellationToken cancelToken)
         {
             Encoding entryNameEncoding = Encoding.UTF8;
@@ -114,20 +118,19 @@ namespace Velopack.Compression
             long totalBytes = directoryInfo.EnumerateFiles("*", SearchOption.AllDirectories).Sum(f => f.Length);
             long processedBytes = 0L;
 
-            var directories = directoryInfo
+            var dirsToProcess = new Stack<DirectoryInfo>();
-                .EnumerateDirectories("*", SearchOption.AllDirectories)
+            dirsToProcess.Push(directoryInfo);
-                .Concat(new[] { directoryInfo })
-                .OrderBy(f => f.FullName)
-                .ToArray();
 
-            foreach (var dir in directories) {
+            while (dirsToProcess.Count > 0) {
                 cancelToken.ThrowIfCancellationRequested();
+                var dir = dirsToProcess.Pop();
 
                 // if dir is a symlink, write it as a file containing path to target
                 if (SymbolicLink.Exists(dir.FullName)) {
                     if (!Utility.IsFileInDirectory(SymbolicLink.GetTarget(dir.FullName, relative: false), sourceDirectoryName)) {
                         throw new IOException("IO_SymlinkTargetNotInDirectory");
                     }
+
                     string entryName = EntryFromPath(dir.FullName, fullName.Length, dir.FullName.Length - fullName.Length);
                     string symlinkTarget = SymbolicLink.GetTarget(dir.FullName, relative: true)
                         .Replace(Path.DirectorySeparatorChar, s_pathSeperator) + s_pathSeperator;
@@ -135,6 +138,7 @@ namespace Velopack.Compression
                     using (var writer = new StreamWriter(entry.Open())) {
                         await writer.WriteAsync(symlinkTarget).ConfigureAwait(false);
                     }
+
                     continue;
                 }
 
@@ -146,7 +150,12 @@ namespace Velopack.Compression
                     continue;
                 }
 
-                // if none of the above, enumerate files and add them to the archive
+                // if none of the above, this is just a regular folder - so we'll enumerate dirs and add them to the search stack and
+                // enumerate files and add them to the archive
+                foreach (var subdir in dir.EnumerateDirectories("*", SearchOption.TopDirectoryOnly)) {
+                    dirsToProcess.Push(subdir);
+                }
+
                 var files = dir
                     .EnumerateFiles("*", SearchOption.TopDirectoryOnly)
                     .OrderBy(f => f.FullName)
@@ -163,12 +172,14 @@ namespace Velopack.Compression
                         if (!Utility.IsFileInDirectory(SymbolicLink.GetTarget(fileInfo.FullName, relative: false), sourceDirectoryName)) {
                             throw new IOException("IO_SymlinkTargetNotInDirectory");
                         }
+
                         string symlinkTarget = SymbolicLink.GetTarget(fileInfo.FullName, relative: true)
                             .Replace(Path.DirectorySeparatorChar, s_pathSeperator);
                         var entry = zipArchive.CreateEntry(entryName + SYMLINK_EXT);
                         using (var writer = new StreamWriter(entry.Open())) {
                             await writer.WriteAsync(symlinkTarget).ConfigureAwait(false);
                         }
+
                         continue;
                     }
 
@@ -225,4 +236,4 @@ namespace Velopack.Compression
             return true;
         }
     }
-}
+}

test/Velopack.Tests/SymbolicLinkTests.cs

@@ -1,4 +1,7 @@
-namespace Velopack.Tests;
+using System.IO.Compression;
+using Velopack.Compression;
+
+namespace Velopack.Tests;
 
 public class SymbolicLinkTests
 {
@@ -220,4 +223,45 @@ public class SymbolicLinkTests
 
         Assert.Throws<IOException>(() => SymbolicLink.Delete(Path.Combine(tempFolder, "AFile")));
     }
+
+    [Fact]
+    public async Task ComplexSymlinkDirGetsZippedCorrectly()
+    {
+        using var _1 = Utility.GetTempDirectory(out var tempFolder);
+        var temp = new DirectoryInfo(tempFolder);
+        var versions = temp.CreateSubdirectory("Versions");
+        var a = versions.CreateSubdirectory("A");
+        var resources = a.CreateSubdirectory("Resources");
+        File.WriteAllText(Path.Combine(resources.FullName, "Info.plist"), "Hello, Resources!");
+        File.WriteAllText(Path.Combine(a.FullName, "App"), "Hello, App!");
+        SymbolicLink.Create(Path.Combine(versions.FullName, "Current"), a.FullName, false, true);
+        SymbolicLink.Create(Path.Combine(temp.FullName, "Resources"), Path.Combine(versions.FullName, "Current", "Resources"), false, true);
+        SymbolicLink.Create(Path.Combine(temp.FullName, "App"), Path.Combine(versions.FullName, "Current", "App"), false, true);
+
+        using var _2 = Utility.GetTempDirectory(out var tempOutput);
+        var output = Path.Combine(tempOutput, "output.zip");
+
+        await EasyZip.CreateZipFromDirectoryAsync(NullLogger.Instance, output, tempFolder);
+        ZipFile.ExtractToDirectory(output, tempOutput);
+
+        var appSym = Path.Combine(tempOutput, "App.__symlink");
+        Assert.True(File.Exists(appSym));
+        Assert.Equal("Versions/Current/App", File.ReadAllText(appSym));
+        
+        var resSym = Path.Combine(tempOutput, "Resources.__symlink");
+        Assert.True(File.Exists(resSym));
+        Assert.Equal("Versions/Current/Resources/", File.ReadAllText(resSym));
+        
+        Assert.True(Directory.Exists(Path.Combine(tempOutput, "Versions")));
+        Assert.False(Directory.Exists(Path.Combine(tempOutput, "App")));
+        Assert.False(Directory.Exists(Path.Combine(tempOutput, "Resources")));
+        
+        Assert.True(Directory.Exists(Path.Combine(tempOutput, "Versions", "A")));
+        Assert.False(Directory.Exists(Path.Combine(tempOutput, "Versions", "Current")));
+        Assert.False(File.Exists(Path.Combine(tempOutput, "Versions", "Current")));
+        
+        var currentSym = Path.Combine(tempOutput, "Versions", "Current.__symlink");
+        Assert.True(File.Exists(currentSym));
+        Assert.Equal("A/", File.ReadAllText(currentSym));
+    }
 }