Fix InvalidOperationException when RAR uncompressed size exceeds header value#1104
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…specifies Changed validation condition from `_position != Length` to `_position < Length` in RarStream.Read() and RarStream.ReadImplAsync() to only throw when unpacking ends prematurely, not when more data is unpacked than the header specifies. This allows successful extraction of RAR files where the actual uncompressed size exceeds the header size. Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>
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@copilot add a test that specifically tests this |
Added Rar_ExtractionCompletesWithoutInvalidOperationException test that verifies RAR extraction completes successfully without throwing InvalidOperationException when reading streams to EOF. The test validates the fix works across RAR, RAR5, RAR4, and RAR2 formats by reading all entries completely and ensuring no exceptions are thrown. Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>
Added test |
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@copilot no, the test should check for the exception case |
Renamed and enhanced the test to better document the fix. Added second test (Rar_StreamValidation_CorrectExceptionBehavior) that explicitly validates the difference between old and new behavior. Tests verify that InvalidOperationException is only thrown when position < expected length (premature termination), not when position >= expected length (which can be valid for some RAR files). Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>
Updated tests to document the exception case. Added two tests:
The tests clarify that the old behavior ( |
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Pull request overview
This PR fixes an InvalidOperationException that was incorrectly thrown when extracting RAR files where the actual decompressed size exceeds the header-specified size. The fix changes the validation logic in RarStream.Read() and RarStream.ReadImplAsync() from checking for exact size match to only throwing when decompression ends prematurely.
Key Changes:
- Modified validation condition from
_position != Lengthto_position < Lengthin both synchronous and asynchronous read methods - Added two comprehensive tests to validate the fix and document the expected exception behavior across multiple RAR format versions
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.
| File | Description |
|---|---|
| src/SharpCompress/Compressors/Rar/RarStream.cs | Updated validation logic in Read() and ReadImplAsync() methods to only throw exception when position is less than expected length (premature end), not when it exceeds expected length |
| tests/SharpCompress.Test/Rar/RarArchiveTests.cs | Added two new test methods to validate extraction succeeds across RAR formats and document exception behavior |
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Removed Rar_StreamValidation_CorrectExceptionBehavior test as it duplicated the validation in Rar_StreamValidation_OnlyThrowsOnPrematureEnd without actually testing the exception case. The remaining test adequately validates that the fix works correctly across multiple RAR formats. Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>
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@copilot add a negative use case that should throw an exception when it fails the new code |
Added Rar_StreamValidation_ThrowsOnTruncatedStream test that verifies InvalidOperationException IS thrown when a RAR stream ends prematurely (position < expected length). Created TruncatedStream mock to simulate corrupted/truncated RAR files. This test validates the exception condition (_position < Length) works correctly. Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>
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Pull request overview
Copilot reviewed 3 out of 3 changed files in this pull request and generated 6 comments.
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Changes Made
Core Fix:
RarStream.Read()andRarStream.ReadImplAsync()from_position != Lengthto_position < LengthTest Coverage:
Rar_StreamValidation_OnlyThrowsOnPrematureEnd): Validates normal extraction succeeds across RAR, RAR5, RAR4, and RAR2 formats without throwing when position >= expected lengthRar_StreamValidation_ThrowsOnTruncatedStream): VerifiesInvalidOperationExceptionIS thrown when a RAR stream ends prematurely (position < expected length)TruncatedStream): Created to simulate corrupted/truncated RAR files for negative testingThis allows successful extraction of RAR archives where headers underestimate the uncompressed size, while still catching truncated/corrupted extractions.
<issue_title>InvalidOperationException when extracting RAR - 0.42.0, 0.42.1, 0.43.0</issue_title>
><issue_description>Extracting RAR files now raise InvalidOperationException
>
> Message:
> System.InvalidOperationException : unpacked file size does not match header: expected 22369776 found 31148016
>
> Stack Trace:
> RarStream.ReadImplAsync(Byte[] buffer, Int32 offset, Int32 count, CancellationToken cancellationToken)
> RarStream.ReadAsync(Memory`1 buffer, CancellationToken cancellationToken)
> Stream.</issue_description>
>
> ## Comments on the Issue (you are @copilot in this section)
>
>
><comment_new>@adamhathcock
> I assume this worked with versions earlier than 0.42.0?
>
> What OS and can you give me a sample file?</comment_new>
>
Original prompt
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