Fix archive extraction to preserve directory structure when options is null by Copilot · Pull Request #1191 · adamhathcock/sharpcompress

Copilot · 2026-02-08T12:38:50Z

WriteToDirectory() and WriteToDirectoryAsync() flatten directory structures when called without explicit options, extracting all files to the root instead of their subdirectories.

Changes

Set ExtractFullPath = true by default in WriteToDirectoryInternal and WriteToDirectoryAsyncInternal
Add test coverage for RAR archives with subdirectories

Example

// Before: files extracted to root, subdirectories created but empty
archive.WriteToDirectory("/output");
// /output/file1.txt
// /output/file2.txt
// /output/subdir/  (empty)

// After: files extracted to correct subdirectories
archive.WriteToDirectory("/output");
// /output/subdir/file1.txt
// /output/subdir/file2.txt

Note

The async file size issue mentioned in the original report is a separate bug in RAR async stream reading, not the extraction logic. Sync extraction produces correct sizes.

Original prompt

This section details on the original issue you should resolve

<issue_title>Incorrect RAR extraction</issue_title>
<issue_description>Given the attached .rar (packaged in .zip only for uploading to GitHub):

IArchive.WriteToDirectory() creates the archive's folders but places all the files at the top level (not in the folders they belong to).

IAsyncArchive.WriteToDirectoryAsync() additionally extracts 766832.tr11dtp with the wrong file size (5MB instead of 4MB).

Using the latest prerelease version of SharpCompress (0.45.0-beta.378) on Windows, .NET 8.

sample.zip

(My workaround is to downgrade to 0.40.0 and extract using IArchive.ExtractAllEntries() -> IReader.MoveToNextEntry() + IReader.WriteEntryToDirectory().)</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes Incorrect RAR extraction #1190

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

- Set default ExtractFullPath=true in WriteToDirectoryInternal methods - Add test case with sample RAR archive containing subdirectories - Tests verify files are extracted to correct subdirectories, not root Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>

Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>

Copilot

Pull request overview

Fixes IArchive.WriteToDirectory() / IAsyncArchive.WriteToDirectoryAsync() default extraction behavior so omitting ExtractionOptions preserves the archive’s internal directory structure instead of flattening files into the destination root.

Changes:

Default ExtractionOptions to ExtractFullPath = true (and Overwrite = true) when options is null in sync/async archive extraction internals.
Add sync + async RAR regression tests ensuring files are extracted into subdirectories when no options are provided.
Update packages.lock.json (includes Microsoft.NET.ILLink.Tasks version changes).

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
`src/SharpCompress/Archives/IArchiveExtensions.cs`	Sets default extraction options when `options` is null during non-solid/non-7z archive extraction.
`src/SharpCompress/Archives/IAsyncArchiveExtensions.cs`	Async equivalent defaulting of extraction options during non-solid/non-7z extraction.
`tests/SharpCompress.Test/Rar/RarArchiveTests.cs`	Adds regression test for `WriteToDirectory()` path preservation (and a sync size assertion).
`tests/SharpCompress.Test/Rar/RarArchiveAsyncTests.cs`	Adds regression test for `WriteToDirectoryAsync()` path preservation.
`src/SharpCompress/packages.lock.json`	Lockfile changes affecting `Microsoft.NET.ILLink.Tasks` versions for `net8.0`/`net10.0`.

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Copilot · 2026-02-09T09:09:35Z

src/SharpCompress/Archives/IArchiveExtensions.cs

+            // When extracting an entire archive, default to extracting with full paths
+            options ??= new ExtractionOptions { ExtractFullPath = true, Overwrite = true };
+


The new default options ??= ...ExtractFullPath=true... is only applied in WriteToDirectoryInternal, which is skipped for solid archives and SevenZip (those go through ExtractAllEntries() + reader.WriteAllToDirectory(...)). As a result, calling archive.WriteToDirectory(dest) without options can still flatten paths for solid/7z archives. Consider applying the same defaulting in the public WriteToDirectory(...) method (before the solid/7z branch), so behavior is consistent across archive types.

Copilot · 2026-02-09T09:09:36Z

src/SharpCompress/Archives/IAsyncArchiveExtensions.cs

+            // When extracting an entire archive, default to extracting with full paths
+            options ??= new ExtractionOptions { ExtractFullPath = true, Overwrite = true };
+


Same as the sync extension: the default ExtractFullPath=true is only applied in WriteToDirectoryAsyncInternal, but solid archives and SevenZip use ExtractAllEntriesAsync() + reader.WriteAllToDirectoryAsync(...) and still receive options=null. To fully fix path flattening when callers omit options, apply the same defaulting in WriteToDirectoryAsync(...) before choosing the solid/7z path.

src/SharpCompress/packages.lock.json

Copilot · 2026-02-09T09:09:36Z

tests/SharpCompress.Test/Rar/RarArchiveTests.cs

+    /// <summary>
+    /// Tests for Issue #1050 - RAR extraction with WriteToDirectory creates folders
+    /// but places all files at the top level instead of in their subdirectories.
+    /// </summary>
+    [Fact]
+    public void Rar_Issue1050_WriteToDirectory_ExtractsToSubdirectories()
+    {


The PR metadata references sharpcompress#1190, but this new test’s XML doc + method name refer to “Issue #1050”. This makes it hard to trace why the test exists. Update the issue number (and potentially the test name/archive filename) to match the actual tracked issue for this change.

tests/SharpCompress.Test/Rar/RarArchiveTests.cs

Copilot · 2026-02-09T09:09:37Z

tests/SharpCompress.Test/Rar/RarArchiveTests.cs

+        // Verify the exact file size of 766832.tr11dtp matches the archive entry size
+        var fileInfo = new FileInfo(Path.Combine(SCRATCH_FILES_PATH, "Braid", "766832.tr11dtp"));
+        Assert.Equal(4867620, fileInfo.Length); // Expected: 4,867,620 bytes
+    }


The comment says the extracted file size is being validated against the archive entry size, but the test currently asserts a hard-coded byte count. This is brittle if the test archive is ever regenerated. Prefer reading the expected size from the corresponding archive entry (or otherwise deriving it from the test data) and asserting equality against that value.

Copilot · 2026-02-09T09:09:37Z

tests/SharpCompress.Test/Rar/RarArchiveAsyncTests.cs

+    /// <summary>
+    /// Tests for Issue #1050 - RAR extraction with WriteToDirectoryAsync creates folders
+    /// but places all files at the top level instead of in their subdirectories.
+    /// </summary>
+    [Fact]
+    public async ValueTask Rar_Issue1050_WriteToDirectoryAsync_ExtractsToSubdirectories()
+    {


Same mismatch as the sync test: PR metadata references #1190, but this new async test refers to “Issue #1050” in the XML doc and method name. Align the issue reference so the test is discoverable and correctly attributed.

src/SharpCompress/packages.lock.json

tests/SharpCompress.Test/Rar/RarArchiveAsyncTests.cs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

kilo-code-bot · 2026-02-09T09:13:51Z

tests/SharpCompress.Test/Rar/RarArchiveTests.cs

+    public void Rar_Issue1050_WriteToDirectory_ExtractsToSubdirectories()
+    {
+        var testFile = "Rar.issue1050.rar";
+        using var fileStream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, testFile));


WARNING: Using File.OpenRead() instead of File.Open(..., FileMode.Open) avoids the unnecessary read/write permissions. The current implementation opens the file with read/write access which is unnecessary for reading an archive.

Suggested change

using var fileStream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, testFile));

using var fileStream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, testFile));

kilo-code-bot · 2026-02-09T09:13:51Z

tests/SharpCompress.Test/Rar/RarArchiveAsyncTests.cs

+    public async ValueTask Rar_Issue1050_WriteToDirectoryAsync_ExtractsToSubdirectories()
+    {
+        var testFile = "Rar.issue1050.rar";
+        using var fileStream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, testFile));


WARNING: Using File.OpenRead() instead of File.Open(..., FileMode.Open) avoids the unnecessary read/write permissions. The current implementation opens the file with read/write access which is unnecessary for reading an archive.

Suggested change

using var fileStream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, testFile));

using var fileStream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, testFile));

kilo-code-bot · 2026-02-09T09:13:52Z

tests/SharpCompress.Test/Rar/RarArchiveTests.cs

+
+        // Verify the exact file size of 766832.tr11dtp matches the archive entry size
+        var fileInfo = new FileInfo(Path.Combine(SCRATCH_FILES_PATH, "Braid", "766832.tr11dtp"));
+        Assert.Equal(4867620, fileInfo.Length); // Expected: 4,867,620 bytes


SUGGESTION: The comment says the extracted file size is being validated, but the assertion doesn't match the comment's stated purpose. The comment says it validates "exact file size...matches the archive entry size" but actually hardcodes 4867620. Consider also verifying against entry.Size to ensure the test validates what the comment describes.

kilo-code-bot · 2026-02-09T09:13:52Z

tests/SharpCompress.Test/Rar/RarArchiveAsyncTests.cs

+    /// </summary>
+    [Fact]
+    public async ValueTask Rar_Issue1050_WriteToDirectoryAsync_ExtractsToSubdirectories()
+    {


SUGGESTION: The PR metadata references sharpcompress#1190, but this new test references Issue #1050. Consider clarifying in the test comment whether this is testing the same issue or a different one, as the mismatch may confuse future maintainers.

kilo-code-bot · 2026-02-09T09:13:52Z

tests/SharpCompress.Test/Rar/RarArchiveTests.cs

+    /// </summary>
+    [Fact]
+    public void Rar_Issue1050_WriteToDirectory_ExtractsToSubdirectories()
+    {


SUGGESTION: The PR metadata references sharpcompress#1190, but this new test references Issue #1050. Consider clarifying in the test comment whether this is testing the same issue or a different one, as the mismatch may confuse future maintainers.

kilo-code-bot · 2026-02-09T09:14:23Z

Code Review Summary

Status: 5 Issues Found | Recommendation: Address before merge

Overview

Severity	Count
CRITICAL	0
WARNING	2
SUGGESTION	3

Issue Details (click to expand)

WARNING

File	Line	Issue
`tests/SharpCompress.Test/Rar/RarArchiveTests.cs`	733	Using `File.Open(..., FileMode.Open)` opens with read/write access unnecessarily
`tests/SharpCompress.Test/Rar/RarArchiveAsyncTests.cs`	729	Using `File.Open(..., FileMode.Open)` opens with read/write access unnecessarily

SUGGESTION

File	Line	Issue
`tests/SharpCompress.Test/Rar/RarArchiveTests.cs`	731	PR references #1190 but test references #1050 - clarify mismatch
`tests/SharpCompress.Test/Rar/RarArchiveAsyncTests.cs`	727	PR references #1190 but test references #1050 - clarify mismatch
`tests/SharpCompress.Test/Rar/RarArchiveTests.cs`	763	File size assertion hardcodes value instead of comparing to entry.Size

Other Observations (not in diff)

Issues found in unchanged code that cannot receive inline comments:

File	Line	Issue
`src/SharpCompress/Archives/IArchiveExtensions.cs`	25-33	Solid/7Zip archives use `WriteAllToDirectory` which doesn't get the new default options - this path may still have the bug
`src/SharpCompress/Archives/IAsyncArchiveExtensions.cs`	30-38	Same issue: solid/7Zip archives bypass the new default options

The fix only applies to WriteToDirectoryInternal but the solid/7Zip code path calls reader.WriteAllToDirectory(destinationDirectory, options) which passes the original options parameter (potentially null) without applying the new defaults.

Files Reviewed (6 files)

src/SharpCompress/Archives/IArchiveExtensions.cs - 1 observation
src/SharpCompress/Archives/IAsyncArchiveExtensions.cs - 1 observation
src/SharpCompress/packages.lock.json - package downgrades (pre-existing comment)
tests/SharpCompress.Test/Rar/RarArchiveTests.cs - 3 issues
tests/SharpCompress.Test/Rar/RarArchiveAsyncTests.cs - 2 issues
tests/TestArchives/Archives/Rar.issue1050.rar - binary test data

Fix these issues in Kilo Cloud

Initial plan

5437d9f

Copilot AI assigned Copilot and adamhathcock Feb 8, 2026

Copilot started work on behalf of adamhathcock February 8, 2026 12:39 View session

Copilot AI and others added 3 commits February 8, 2026 12:52

Address code review feedback: clarify file size comment

d5cab81

Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>

Complete fix for RAR extraction subdirectory issue

2a40813

Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix incorrect RAR extraction for folders and file sizes~~ Fix archive extraction to preserve directory structure when options is null Feb 8, 2026

Copilot AI requested a review from adamhathcock February 8, 2026 12:57

Copilot finished work on behalf of adamhathcock February 8, 2026 12:57

adamhathcock approved these changes Feb 9, 2026

View reviewed changes

adamhathcock marked this pull request as ready for review February 9, 2026 09:05

Copilot AI review requested due to automatic review settings February 9, 2026 09:05

Copilot started reviewing on behalf of adamhathcock February 9, 2026 09:05 View session

Copilot AI reviewed Feb 9, 2026

View reviewed changes

adamhathcock and others added 2 commits February 9, 2026 09:10

Update tests/SharpCompress.Test/Rar/RarArchiveTests.cs

29197f2

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Update tests/SharpCompress.Test/Rar/RarArchiveAsyncTests.cs

c4a28e7

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

kilo-code-bot bot reviewed Feb 9, 2026

View reviewed changes

adamhathcock mentioned this pull request Feb 9, 2026

Change and clean up options #1193

Merged

adamhathcock closed this pull request by merging all changes into master in e1df655 Feb 10, 2026

adamhathcock deleted the copilot/fix-rar-extraction-issues branch February 10, 2026 11:21

		// When extracting an entire archive, default to extracting with full paths
		options ??= new ExtractionOptions { ExtractFullPath = true, Overwrite = true };

	using var fileStream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, testFile));
	using var fileStream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, testFile));

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Copilot AI commented Feb 8, 2026 •

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