Merge pull request #1160 from adamhathcock/adam/check-if-seek

add check to see if we need to seek before hand

src/SharpCompress/Compressors/BZip2/BZip2Stream.cs

@@ -30,6 +30,7 @@ public sealed class BZip2Stream : Stream, IStreamStack
 
     private readonly Stream stream;
     private bool isDisposed;
+    private readonly bool leaveOpen;
 
     /// <summary>
     /// Create a BZip2Stream
@@ -37,19 +38,30 @@ public sealed class BZip2Stream : Stream, IStreamStack
     /// <param name="stream">The stream to read from</param>
     /// <param name="compressionMode">Compression Mode</param>
     /// <param name="decompressConcatenated">Decompress Concatenated</param>
-    public BZip2Stream(Stream stream, CompressionMode compressionMode, bool decompressConcatenated)
+    /// <param name="leaveOpen">Leave the stream open after disposing</param>
+    public BZip2Stream(
+        Stream stream,
+        CompressionMode compressionMode,
+        bool decompressConcatenated,
+        bool leaveOpen = false
+    )
     {
 #if DEBUG_STREAMS
         this.DebugConstruct(typeof(BZip2Stream));
 #endif
+        this.leaveOpen = leaveOpen;
         Mode = compressionMode;
         if (Mode == CompressionMode.Compress)
         {
-            this.stream = new CBZip2OutputStream(stream);
+            this.stream = new CBZip2OutputStream(stream, 9, leaveOpen);
         }
         else
         {
-            this.stream = new CBZip2InputStream(stream, decompressConcatenated);
+            this.stream = new CBZip2InputStream(
+                stream,
+                decompressConcatenated,
+                leaveOpen: leaveOpen
+            );
         }
     }
 

src/SharpCompress/Compressors/BZip2/CBZip2InputStream.cs

@@ -168,6 +168,7 @@ internal class CBZip2InputStream : Stream, IStreamStack
     private int computedBlockCRC,
         computedCombinedCRC;
     private readonly bool decompressConcatenated;
+    private readonly bool leaveOpen;
 
     private int i2,
         count,
@@ -181,9 +182,10 @@ internal class CBZip2InputStream : Stream, IStreamStack
     private char z;
     private bool isDisposed;
 
-    public CBZip2InputStream(Stream zStream, bool decompressConcatenated)
+    public CBZip2InputStream(Stream zStream, bool decompressConcatenated, bool leaveOpen = false)
     {
         this.decompressConcatenated = decompressConcatenated;
+        this.leaveOpen = leaveOpen;
         ll8 = null;
         tt = null;
         BsSetStream(zStream);
@@ -207,7 +209,10 @@ internal class CBZip2InputStream : Stream, IStreamStack
         this.DebugDispose(typeof(CBZip2InputStream));
 #endif
         base.Dispose(disposing);
-        bsStream?.Dispose();
+        if (!leaveOpen)
+        {
+            bsStream?.Dispose();
+        }
     }
 
     internal static int[][] InitIntArray(int n1, int n2)
@@ -398,7 +403,10 @@ internal class CBZip2InputStream : Stream, IStreamStack
 
     private void BsFinishedWithStream()
     {
-        bsStream?.Dispose();
+        if (!leaveOpen)
+        {
+            bsStream?.Dispose();
+        }
         bsStream = null;
     }
 

src/SharpCompress/Compressors/BZip2/CBZip2OutputStream.cs

@@ -341,12 +341,14 @@ internal sealed class CBZip2OutputStream : Stream, IStreamStack
 
     private int currentChar = -1;
     private int runLength;
+    private readonly bool leaveOpen;
 
-    public CBZip2OutputStream(Stream inStream)
-        : this(inStream, 9) { }
+    public CBZip2OutputStream(Stream inStream, bool leaveOpen = false)
+        : this(inStream, 9, leaveOpen) { }
 
-    public CBZip2OutputStream(Stream inStream, int inBlockSize)
+    public CBZip2OutputStream(Stream inStream, int inBlockSize, bool leaveOpen = false)
     {
+        this.leaveOpen = leaveOpen;
         block = null;
         quadrant = null;
         zptr = null;
@@ -481,7 +483,10 @@ internal sealed class CBZip2OutputStream : Stream, IStreamStack
             this.DebugDispose(typeof(CBZip2OutputStream));
 #endif
             Dispose();
-            bsStream?.Dispose();
+            if (!leaveOpen)
+            {
+                bsStream?.Dispose();
+            }
             bsStream = null;
         }
     }

src/SharpCompress/Compressors/Deflate/ZlibBaseStream.cs

@@ -586,7 +586,13 @@ internal class ZlibBaseStream : Stream, IStreamStack
 
     public override void Flush()
     {
-        _stream.Flush();
+        // Only flush the underlying stream when in write mode
+        // Flushing input streams during read operations is not meaningful
+        // and can cause issues with forward-only/non-seekable streams
+        if (_streamMode == StreamMode.Writer)
+        {
+            _stream.Flush();
+        }
         //rewind the buffer
         ((IStreamStack)this).Rewind(z.AvailableBytesIn); //unused
         z.AvailableBytesIn = 0;
@@ -594,7 +600,13 @@ internal class ZlibBaseStream : Stream, IStreamStack
 
     public override async Task FlushAsync(CancellationToken cancellationToken)
     {
-        await _stream.FlushAsync(cancellationToken).ConfigureAwait(false);
+        // Only flush the underlying stream when in write mode
+        // Flushing input streams during read operations is not meaningful
+        // and can cause issues with forward-only/non-seekable streams
+        if (_streamMode == StreamMode.Writer)
+        {
+            await _stream.FlushAsync(cancellationToken).ConfigureAwait(false);
+        }
         //rewind the buffer
         ((IStreamStack)this).Rewind(z.AvailableBytesIn); //unused
         z.AvailableBytesIn = 0;

src/SharpCompress/Compressors/LZMA/LZipStream.cs

@@ -46,11 +46,13 @@ public sealed class LZipStream : Stream, IStreamStack
 
     private long _writeCount;
     private readonly Stream? _originalStream;
+    private readonly bool _leaveOpen;
 
-    public LZipStream(Stream stream, CompressionMode mode)
+    public LZipStream(Stream stream, CompressionMode mode, bool leaveOpen = false)
     {
         Mode = mode;
         _originalStream = stream;
+        _leaveOpen = leaveOpen;
 
         if (mode == CompressionMode.Decompress)
         {
@@ -60,7 +62,7 @@ public sealed class LZipStream : Stream, IStreamStack
                 throw new InvalidFormatException("Not an LZip stream");
             }
             var properties = GetProperties(dSize);
-            _stream = new LzmaStream(properties, stream);
+            _stream = new LzmaStream(properties, stream, leaveOpen: leaveOpen);
         }
         else
         {
@@ -127,7 +129,7 @@ public sealed class LZipStream : Stream, IStreamStack
         {
             Finish();
             _stream.Dispose();
-            if (Mode == CompressionMode.Compress)
+            if (Mode == CompressionMode.Compress && !_leaveOpen)
             {
                 _originalStream?.Dispose();
             }

src/SharpCompress/Compressors/LZMA/LzmaStream.cs

@@ -35,6 +35,7 @@ public class LzmaStream : Stream, IStreamStack
     private readonly Stream _inputStream;
     private readonly long _inputSize;
     private readonly long _outputSize;
+    private readonly bool _leaveOpen;
 
     private readonly int _dictionarySize;
     private readonly OutWindow _outWindow = new();
@@ -56,14 +57,28 @@ public class LzmaStream : Stream, IStreamStack
     private readonly Encoder _encoder;
     private bool _isDisposed;
 
-    public LzmaStream(byte[] properties, Stream inputStream)
-        : this(properties, inputStream, -1, -1, null, properties.Length < 5) { }
+    public LzmaStream(byte[] properties, Stream inputStream, bool leaveOpen = false)
+        : this(properties, inputStream, -1, -1, null, properties.Length < 5, leaveOpen) { }
 
-    public LzmaStream(byte[] properties, Stream inputStream, long inputSize)
-        : this(properties, inputStream, inputSize, -1, null, properties.Length < 5) { }
+    public LzmaStream(byte[] properties, Stream inputStream, long inputSize, bool leaveOpen = false)
+        : this(properties, inputStream, inputSize, -1, null, properties.Length < 5, leaveOpen) { }
 
-    public LzmaStream(byte[] properties, Stream inputStream, long inputSize, long outputSize)
-        : this(properties, inputStream, inputSize, outputSize, null, properties.Length < 5) { }
+    public LzmaStream(
+        byte[] properties,
+        Stream inputStream,
+        long inputSize,
+        long outputSize,
+        bool leaveOpen = false
+    )
+        : this(
+            properties,
+            inputStream,
+            inputSize,
+            outputSize,
+            null,
+            properties.Length < 5,
+            leaveOpen
+        ) { }
 
     public LzmaStream(
         byte[] properties,
@@ -71,13 +86,15 @@ public class LzmaStream : Stream, IStreamStack
         long inputSize,
         long outputSize,
         Stream presetDictionary,
-        bool isLzma2
+        bool isLzma2,
+        bool leaveOpen = false
     )
     {
         _inputStream = inputStream;
         _inputSize = inputSize;
         _outputSize = outputSize;
         _isLzma2 = isLzma2;
+        _leaveOpen = leaveOpen;
 
 #if DEBUG_STREAMS
         this.DebugConstruct(typeof(LzmaStream));
@@ -179,7 +196,10 @@ public class LzmaStream : Stream, IStreamStack
             {
                 _position = _encoder.Code(null, true);
             }
-            _inputStream?.Dispose();
+            if (!_leaveOpen)
+            {
+                _inputStream?.Dispose();
+            }
             _outWindow.Dispose();
         }
         base.Dispose(disposing);

src/SharpCompress/IO/BufferedSubStream.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Buffers;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
@@ -28,14 +29,25 @@ internal class BufferedSubStream : SharpCompressStream, IStreamStack
 #if DEBUG_STREAMS
         this.DebugDispose(typeof(BufferedSubStream));
 #endif
-        if (disposing) { }
+        if (_isDisposed)
+        {
+            return;
+        }
+        _isDisposed = true;
+
+        if (disposing && _cache is not null)
+        {
+            ArrayPool<byte>.Shared.Return(_cache);
+            _cache = null;
+        }
         base.Dispose(disposing);
     }
 
     private int _cacheOffset;
     private int _cacheLength;
-    private readonly byte[] _cache = new byte[32 << 10];
+    private byte[]? _cache = ArrayPool<byte>.Shared.Rent(81920);
     private long origin;
+    private bool _isDisposed;
 
     private long BytesLeftToRead { get; set; }
 
@@ -57,14 +69,26 @@ internal class BufferedSubStream : SharpCompressStream, IStreamStack
 
     private void RefillCache()
     {
-        var count = (int)Math.Min(BytesLeftToRead, _cache.Length);
+        if (_isDisposed)
+        {
+            throw new ObjectDisposedException(nameof(BufferedSubStream));
+        }
+
+        var count = (int)Math.Min(BytesLeftToRead, _cache!.Length);
         _cacheOffset = 0;
         if (count == 0)
         {
             _cacheLength = 0;
             return;
         }
-        Stream.Position = origin;
+
+        // Only seek if we're not already at the correct position
+        // This avoids expensive seek operations when reading sequentially
+        if (Stream.CanSeek && Stream.Position != origin)
+        {
+            Stream.Position = origin;
+        }
+
         _cacheLength = Stream.Read(_cache, 0, count);
         origin += _cacheLength;
         BytesLeftToRead -= _cacheLength;
@@ -72,14 +96,24 @@ internal class BufferedSubStream : SharpCompressStream, IStreamStack
 
     private async ValueTask RefillCacheAsync(CancellationToken cancellationToken)
     {
-        var count = (int)Math.Min(BytesLeftToRead, _cache.Length);
+        if (_isDisposed)
+        {
+            throw new ObjectDisposedException(nameof(BufferedSubStream));
+        }
+
+        var count = (int)Math.Min(BytesLeftToRead, _cache!.Length);
         _cacheOffset = 0;
         if (count == 0)
         {
             _cacheLength = 0;
             return;
         }
-        Stream.Position = origin;
+        // Only seek if we're not already at the correct position
+        // This avoids expensive seek operations when reading sequentially
+        if (Stream.CanSeek && Stream.Position != origin)
+        {
+            Stream.Position = origin;
+        }
         _cacheLength = await Stream
             .ReadAsync(_cache, 0, count, cancellationToken)
             .ConfigureAwait(false);
@@ -102,7 +136,7 @@ internal class BufferedSubStream : SharpCompressStream, IStreamStack
             }
 
             count = Math.Min(count, _cacheLength - _cacheOffset);
-            Buffer.BlockCopy(_cache, _cacheOffset, buffer, offset, count);
+            Buffer.BlockCopy(_cache!, _cacheOffset, buffer, offset, count);
             _cacheOffset += count;
         }
 
@@ -120,7 +154,7 @@ internal class BufferedSubStream : SharpCompressStream, IStreamStack
             }
         }
 
-        return _cache[_cacheOffset++];
+        return _cache![_cacheOffset++];
     }
 
     public override async Task<int> ReadAsync(
@@ -143,7 +177,7 @@ internal class BufferedSubStream : SharpCompressStream, IStreamStack
             }
 
             count = Math.Min(count, _cacheLength - _cacheOffset);
-            Buffer.BlockCopy(_cache, _cacheOffset, buffer, offset, count);
+            Buffer.BlockCopy(_cache!, _cacheOffset, buffer, offset, count);
             _cacheOffset += count;
         }
 
@@ -170,7 +204,7 @@ internal class BufferedSubStream : SharpCompressStream, IStreamStack
             }
 
             count = Math.Min(count, _cacheLength - _cacheOffset);
-            _cache.AsSpan(_cacheOffset, count).CopyTo(buffer.Span);
+            _cache!.AsSpan(_cacheOffset, count).CopyTo(buffer.Span);
             _cacheOffset += count;
         }
 

src/SharpCompress/IO/SharpCompressStream.cs

@@ -257,7 +257,6 @@ public class SharpCompressStream : Stream, IStreamStack
             ValidateBufferState();
         }
 
-        long orig = _internalPosition;
         long targetPos;
         // Calculate the absolute target position based on origin
         switch (origin)

tests/SharpCompress.Test/Mocks/ThrowOnFlushStream.cs

@@ -0,0 +1,73 @@
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace SharpCompress.Test.Mocks;
+
+/// <summary>
+/// A stream wrapper that throws NotSupportedException on Flush() calls.
+/// This is used to test that archive iteration handles streams that don't support flushing.
+/// </summary>
+public class ThrowOnFlushStream : Stream
+{
+    private readonly Stream inner;
+
+    public ThrowOnFlushStream(Stream inner)
+    {
+        this.inner = inner;
+    }
+
+    public override bool CanRead => inner.CanRead;
+
+    public override bool CanSeek => false;
+
+    public override bool CanWrite => false;
+
+    public override long Length => throw new NotSupportedException();
+
+    public override long Position
+    {
+        get => throw new NotSupportedException();
+        set => throw new NotSupportedException();
+    }
+
+    public override void Flush() => throw new NotSupportedException("Flush not supported");
+
+    public override Task FlushAsync(CancellationToken cancellationToken) =>
+        throw new NotSupportedException("FlushAsync not supported");
+
+    public override int Read(byte[] buffer, int offset, int count) =>
+        inner.Read(buffer, offset, count);
+
+    public override Task<int> ReadAsync(
+        byte[] buffer,
+        int offset,
+        int count,
+        CancellationToken cancellationToken
+    ) => inner.ReadAsync(buffer, offset, count, cancellationToken);
+
+#if !NETFRAMEWORK && !NETSTANDARD2_0
+    public override ValueTask<int> ReadAsync(
+        Memory<byte> buffer,
+        CancellationToken cancellationToken = default
+    ) => inner.ReadAsync(buffer, cancellationToken);
+#endif
+
+    public override long Seek(long offset, SeekOrigin origin) => throw new NotSupportedException();
+
+    public override void SetLength(long value) => throw new NotSupportedException();
+
+    public override void Write(byte[] buffer, int offset, int count) =>
+        throw new NotSupportedException();
+
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing)
+        {
+            inner.Dispose();
+        }
+
+        base.Dispose(disposing);
+    }
+}

tests/SharpCompress.Test/SharpCompress.Test.csproj

@@ -9,6 +9,9 @@
   <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|net10.0|AnyCPU'">
     <DefineConstants>$(DefineConstants);DEBUG_STREAMS</DefineConstants>
   </PropertyGroup>
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net48' ">
+    <DefineConstants>$(DefineConstants);LEGACY_DOTNET</DefineConstants>
+  </PropertyGroup>
   <PropertyGroup Condition="$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::Windows)))">
     <DefineConstants>$(DefineConstants);WINDOWS</DefineConstants>
   </PropertyGroup>
@@ -25,7 +28,7 @@
     <PackageReference Include="xunit" />
     <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(VersionlessImplicitFrameworkDefine)' != 'NETFRAMEWORK' ">
+  <ItemGroup Condition="$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::Linux)))">
     <PackageReference Include="Mono.Posix.NETStandard" />
   </ItemGroup>
 </Project>

tests/SharpCompress.Test/Streams/DisposalTests.cs

@@ -2,6 +2,7 @@ using System;
 using System.IO;
 using SharpCompress.Common;
 using SharpCompress.Compressors;
+using SharpCompress.Compressors.BZip2;
 using SharpCompress.Compressors.Deflate;
 using SharpCompress.Compressors.LZMA;
 using SharpCompress.Compressors.Lzw;
@@ -152,9 +153,21 @@ public class DisposalTests
     [Fact]
     public void LZipStream_Disposal()
     {
-        // LZipStream always disposes inner stream
+        // LZipStream now supports leaveOpen parameter
         // Use Compress mode to avoid need for valid input header
-        VerifyAlwaysDispose(stream => new LZipStream(stream, CompressionMode.Compress));
+        VerifyStreamDisposal(
+            (stream, leaveOpen) => new LZipStream(stream, CompressionMode.Compress, leaveOpen)
+        );
+    }
+
+    [Fact]
+    public void BZip2Stream_Disposal()
+    {
+        // BZip2Stream now supports leaveOpen parameter
+        VerifyStreamDisposal(
+            (stream, leaveOpen) =>
+                new BZip2Stream(stream, CompressionMode.Compress, false, leaveOpen)
+        );
     }
 
     [Fact]

tests/SharpCompress.Test/Streams/LeaveOpenBehaviorTests.cs

@@ -0,0 +1,226 @@
+using System;
+using System.IO;
+using System.Text;
+using SharpCompress.Compressors;
+using SharpCompress.Compressors.BZip2;
+using SharpCompress.Compressors.LZMA;
+using SharpCompress.Test.Mocks;
+using Xunit;
+
+namespace SharpCompress.Test.Streams;
+
+public class LeaveOpenBehaviorTests
+{
+    private static byte[] CreateTestData() =>
+        Encoding.UTF8.GetBytes("The quick brown fox jumps over the lazy dog");
+
+    [Fact]
+    public void BZip2Stream_Compress_LeaveOpen_False()
+    {
+        using var innerStream = new TestStream(new MemoryStream());
+        using (
+            var bzip2 = new BZip2Stream(
+                innerStream,
+                CompressionMode.Compress,
+                false,
+                leaveOpen: false
+            )
+        )
+        {
+            bzip2.Write(CreateTestData(), 0, CreateTestData().Length);
+            bzip2.Finish();
+        }
+
+        Assert.True(innerStream.IsDisposed, "Inner stream should be disposed when leaveOpen=false");
+    }
+
+    [Fact]
+    public void BZip2Stream_Compress_LeaveOpen_True()
+    {
+        using var innerStream = new TestStream(new MemoryStream());
+        byte[] compressed;
+        using (
+            var bzip2 = new BZip2Stream(
+                innerStream,
+                CompressionMode.Compress,
+                false,
+                leaveOpen: true
+            )
+        )
+        {
+            bzip2.Write(CreateTestData(), 0, CreateTestData().Length);
+            bzip2.Finish();
+        }
+
+        Assert.False(
+            innerStream.IsDisposed,
+            "Inner stream should NOT be disposed when leaveOpen=true"
+        );
+
+        // Should be able to read the compressed data
+        innerStream.Position = 0;
+        compressed = new byte[innerStream.Length];
+        innerStream.Read(compressed, 0, compressed.Length);
+        Assert.True(compressed.Length > 0);
+    }
+
+    [Fact]
+    public void BZip2Stream_Decompress_LeaveOpen_False()
+    {
+        // First compress some data
+        var memStream = new MemoryStream();
+        using (var bzip2 = new BZip2Stream(memStream, CompressionMode.Compress, false, true))
+        {
+            bzip2.Write(CreateTestData(), 0, CreateTestData().Length);
+            bzip2.Finish();
+        }
+
+        memStream.Position = 0;
+        using var innerStream = new TestStream(memStream);
+        var decompressed = new byte[CreateTestData().Length];
+
+        using (
+            var bzip2 = new BZip2Stream(
+                innerStream,
+                CompressionMode.Decompress,
+                false,
+                leaveOpen: false
+            )
+        )
+        {
+            bzip2.Read(decompressed, 0, decompressed.Length);
+        }
+
+        Assert.True(innerStream.IsDisposed, "Inner stream should be disposed when leaveOpen=false");
+        Assert.Equal(CreateTestData(), decompressed);
+    }
+
+    [Fact]
+    public void BZip2Stream_Decompress_LeaveOpen_True()
+    {
+        // First compress some data
+        var memStream = new MemoryStream();
+        using (var bzip2 = new BZip2Stream(memStream, CompressionMode.Compress, false, true))
+        {
+            bzip2.Write(CreateTestData(), 0, CreateTestData().Length);
+            bzip2.Finish();
+        }
+
+        memStream.Position = 0;
+        using var innerStream = new TestStream(memStream);
+        var decompressed = new byte[CreateTestData().Length];
+
+        using (
+            var bzip2 = new BZip2Stream(
+                innerStream,
+                CompressionMode.Decompress,
+                false,
+                leaveOpen: true
+            )
+        )
+        {
+            bzip2.Read(decompressed, 0, decompressed.Length);
+        }
+
+        Assert.False(
+            innerStream.IsDisposed,
+            "Inner stream should NOT be disposed when leaveOpen=true"
+        );
+        Assert.Equal(CreateTestData(), decompressed);
+
+        // Should still be able to use the stream
+        innerStream.Position = 0;
+        Assert.True(innerStream.CanRead);
+    }
+
+    [Fact]
+    public void LZipStream_Compress_LeaveOpen_False()
+    {
+        using var innerStream = new TestStream(new MemoryStream());
+        using (var lzip = new LZipStream(innerStream, CompressionMode.Compress, leaveOpen: false))
+        {
+            lzip.Write(CreateTestData(), 0, CreateTestData().Length);
+            lzip.Finish();
+        }
+
+        Assert.True(innerStream.IsDisposed, "Inner stream should be disposed when leaveOpen=false");
+    }
+
+    [Fact]
+    public void LZipStream_Compress_LeaveOpen_True()
+    {
+        using var innerStream = new TestStream(new MemoryStream());
+        byte[] compressed;
+        using (var lzip = new LZipStream(innerStream, CompressionMode.Compress, leaveOpen: true))
+        {
+            lzip.Write(CreateTestData(), 0, CreateTestData().Length);
+            lzip.Finish();
+        }
+
+        Assert.False(
+            innerStream.IsDisposed,
+            "Inner stream should NOT be disposed when leaveOpen=true"
+        );
+
+        // Should be able to read the compressed data
+        innerStream.Position = 0;
+        compressed = new byte[innerStream.Length];
+        innerStream.Read(compressed, 0, compressed.Length);
+        Assert.True(compressed.Length > 0);
+    }
+
+    [Fact]
+    public void LZipStream_Decompress_LeaveOpen_False()
+    {
+        // First compress some data
+        var memStream = new MemoryStream();
+        using (var lzip = new LZipStream(memStream, CompressionMode.Compress, true))
+        {
+            lzip.Write(CreateTestData(), 0, CreateTestData().Length);
+            lzip.Finish();
+        }
+
+        memStream.Position = 0;
+        using var innerStream = new TestStream(memStream);
+        var decompressed = new byte[CreateTestData().Length];
+
+        using (var lzip = new LZipStream(innerStream, CompressionMode.Decompress, leaveOpen: false))
+        {
+            lzip.Read(decompressed, 0, decompressed.Length);
+        }
+
+        Assert.True(innerStream.IsDisposed, "Inner stream should be disposed when leaveOpen=false");
+        Assert.Equal(CreateTestData(), decompressed);
+    }
+
+    [Fact]
+    public void LZipStream_Decompress_LeaveOpen_True()
+    {
+        // First compress some data
+        var memStream = new MemoryStream();
+        using (var lzip = new LZipStream(memStream, CompressionMode.Compress, true))
+        {
+            lzip.Write(CreateTestData(), 0, CreateTestData().Length);
+            lzip.Finish();
+        }
+
+        memStream.Position = 0;
+        using var innerStream = new TestStream(memStream);
+        var decompressed = new byte[CreateTestData().Length];
+
+        using (var lzip = new LZipStream(innerStream, CompressionMode.Decompress, leaveOpen: true))
+        {
+            lzip.Read(decompressed, 0, decompressed.Length);
+        }
+
+        Assert.False(
+            innerStream.IsDisposed,
+            "Inner stream should NOT be disposed when leaveOpen=true"
+        );
+        Assert.Equal(CreateTestData(), decompressed);
+
+        // Should still be able to use the stream
+        innerStream.Position = 0;
+        Assert.True(innerStream.CanRead);
+    }
+}

tests/SharpCompress.Test/Streams/SharpCompressStreamTest.cs

@@ -5,6 +5,7 @@ using System.Linq;
 using System.Text;
 using SharpCompress.Compressors.LZMA;
 using SharpCompress.IO;
+using SharpCompress.Test.Mocks;
 using Xunit;
 
 namespace SharpCompress.Test.Streams;
@@ -64,7 +65,14 @@ public class SharpCompressStreamTests
         {
             createData(ms);
 
-            using (SharpCompressStream scs = new SharpCompressStream(ms, true, false, 0x10000))
+            using (
+                SharpCompressStream scs = new SharpCompressStream(
+                    new ForwardOnlyStream(ms),
+                    true,
+                    false,
+                    0x10000
+                )
+            )
             {
                 IStreamStack stack = (IStreamStack)scs;
 
@@ -89,4 +97,25 @@ public class SharpCompressStreamTests
             }
         }
     }
+
+    [Fact]
+    public void BufferedSubStream_DoubleDispose_DoesNotCorruptArrayPool()
+    {
+        // This test verifies that calling Dispose multiple times on BufferedSubStream
+        // doesn't return the same array to the pool twice, which would cause pool corruption
+        byte[] data = new byte[0x10000];
+        using (MemoryStream ms = new MemoryStream(data))
+        {
+            var stream = new BufferedSubStream(ms, 0, data.Length);
+
+            // First disposal
+            stream.Dispose();
+
+            // Second disposal should not throw or corrupt the pool
+            stream.Dispose();
+        }
+
+        // If we got here without an exception, the test passed
+        Assert.True(true);
+    }
 }

tests/SharpCompress.Test/Zip/ZipReaderAsyncTests.cs

@@ -251,4 +251,106 @@ public class ZipReaderAsyncTests : ReaderTests
         }
         Assert.Equal(8, count);
     }
+
+    [Fact]
+    public async ValueTask EntryStream_Dispose_DoesNotThrow_OnNonSeekableStream_Deflate_Async()
+    {
+        // Since version 0.41.0: EntryStream.DisposeAsync() should not throw NotSupportedException
+        // when FlushAsync() fails on non-seekable streams (Deflate compression)
+        var path = Path.Combine(TEST_ARCHIVES_PATH, "Zip.deflate.dd.zip");
+        using Stream stream = new ForwardOnlyStream(File.OpenRead(path));
+        using var reader = ReaderFactory.Open(stream);
+
+        // This should not throw, even if internal FlushAsync() fails
+        while (await reader.MoveToNextEntryAsync())
+        {
+            if (!reader.Entry.IsDirectory)
+            {
+#if LEGACY_DOTNET
+                using var entryStream = await reader.OpenEntryStreamAsync();
+#else
+                await using var entryStream = await reader.OpenEntryStreamAsync();
+#endif
+                // Read some data
+                var buffer = new byte[1024];
+                await entryStream.ReadAsync(buffer, 0, buffer.Length);
+                // DisposeAsync should not throw NotSupportedException
+            }
+        }
+    }
+
+    [Fact]
+    public async ValueTask EntryStream_Dispose_DoesNotThrow_OnNonSeekableStream_LZMA_Async()
+    {
+        // Since version 0.41.0: EntryStream.DisposeAsync() should not throw NotSupportedException
+        // when FlushAsync() fails on non-seekable streams (LZMA compression)
+        var path = Path.Combine(TEST_ARCHIVES_PATH, "Zip.lzma.dd.zip");
+        using Stream stream = new ForwardOnlyStream(File.OpenRead(path));
+        using var reader = ReaderFactory.Open(stream);
+
+        // This should not throw, even if internal FlushAsync() fails
+        while (await reader.MoveToNextEntryAsync())
+        {
+            if (!reader.Entry.IsDirectory)
+            {
+#if LEGACY_DOTNET
+                using var entryStream = await reader.OpenEntryStreamAsync();
+#else
+                await using var entryStream = await reader.OpenEntryStreamAsync();
+#endif
+                // Read some data
+                var buffer = new byte[1024];
+                await entryStream.ReadAsync(buffer, 0, buffer.Length);
+                // DisposeAsync should not throw NotSupportedException
+            }
+        }
+    }
+
+    [Fact]
+    public async ValueTask Archive_Iteration_DoesNotBreak_WhenFlushThrows_Deflate_Async()
+    {
+        // Regression test: since 0.41.0, archive iteration would silently break
+        // when the input stream throws NotSupportedException in Flush().
+        // Only the first entry would be returned, then iteration would stop without exception.
+        var path = Path.Combine(TEST_ARCHIVES_PATH, "Zip.deflate.dd.zip");
+        using var fileStream = File.OpenRead(path);
+        using Stream stream = new ThrowOnFlushStream(fileStream);
+        using var reader = ReaderFactory.Open(stream);
+
+        var count = 0;
+        while (await reader.MoveToNextEntryAsync())
+        {
+            if (!reader.Entry.IsDirectory)
+            {
+                count++;
+            }
+        }
+
+        // Should iterate through all entries, not just the first one
+        Assert.True(count > 1, $"Expected more than 1 entry, but got {count}");
+    }
+
+    [Fact]
+    public async ValueTask Archive_Iteration_DoesNotBreak_WhenFlushThrows_LZMA_Async()
+    {
+        // Regression test: since 0.41.0, archive iteration would silently break
+        // when the input stream throws NotSupportedException in Flush().
+        // Only the first entry would be returned, then iteration would stop without exception.
+        var path = Path.Combine(TEST_ARCHIVES_PATH, "Zip.lzma.dd.zip");
+        using var fileStream = File.OpenRead(path);
+        using Stream stream = new ThrowOnFlushStream(fileStream);
+        using var reader = ReaderFactory.Open(stream);
+
+        var count = 0;
+        while (await reader.MoveToNextEntryAsync())
+        {
+            if (!reader.Entry.IsDirectory)
+            {
+                count++;
+            }
+        }
+
+        // Should iterate through all entries, not just the first one
+        Assert.True(count > 1, $"Expected more than 1 entry, but got {count}");
+    }
 }

tests/SharpCompress.Test/Zip/ZipReaderTests.cs

@@ -436,4 +436,98 @@ public class ZipReaderTests : ReaderTests
             Assert.Equal(archiveKeys.OrderBy(k => k), readerKeys.OrderBy(k => k));
         }
     }
+
+    [Fact]
+    public void EntryStream_Dispose_DoesNotThrow_OnNonSeekableStream_Deflate()
+    {
+        // Since version 0.41.0: EntryStream.Dispose() should not throw NotSupportedException
+        // when Flush() fails on non-seekable streams (Deflate compression)
+        var path = Path.Combine(TEST_ARCHIVES_PATH, "Zip.deflate.dd.zip");
+        using Stream stream = new ForwardOnlyStream(File.OpenRead(path));
+        using var reader = ReaderFactory.Open(stream);
+
+        // This should not throw, even if internal Flush() fails
+        while (reader.MoveToNextEntry())
+        {
+            if (!reader.Entry.IsDirectory)
+            {
+                using var entryStream = reader.OpenEntryStream();
+                // Read some data
+                var buffer = new byte[1024];
+                entryStream.Read(buffer, 0, buffer.Length);
+                // Dispose should not throw NotSupportedException
+            }
+        }
+    }
+
+    [Fact]
+    public void EntryStream_Dispose_DoesNotThrow_OnNonSeekableStream_LZMA()
+    {
+        // Since version 0.41.0: EntryStream.Dispose() should not throw NotSupportedException
+        // when Flush() fails on non-seekable streams (LZMA compression)
+        var path = Path.Combine(TEST_ARCHIVES_PATH, "Zip.lzma.dd.zip");
+        using Stream stream = new ForwardOnlyStream(File.OpenRead(path));
+        using var reader = ReaderFactory.Open(stream);
+
+        // This should not throw, even if internal Flush() fails
+        while (reader.MoveToNextEntry())
+        {
+            if (!reader.Entry.IsDirectory)
+            {
+                using var entryStream = reader.OpenEntryStream();
+                // Read some data
+                var buffer = new byte[1024];
+                entryStream.Read(buffer, 0, buffer.Length);
+                // Dispose should not throw NotSupportedException
+            }
+        }
+    }
+
+    [Fact]
+    public void Archive_Iteration_DoesNotBreak_WhenFlushThrows_Deflate()
+    {
+        // Regression test: since 0.41.0, archive iteration would silently break
+        // when the input stream throws NotSupportedException in Flush().
+        // Only the first entry would be returned, then iteration would stop without exception.
+        var path = Path.Combine(TEST_ARCHIVES_PATH, "Zip.deflate.dd.zip");
+        using var fileStream = File.OpenRead(path);
+        using Stream stream = new ThrowOnFlushStream(fileStream);
+        using var reader = ReaderFactory.Open(stream);
+
+        var count = 0;
+        while (reader.MoveToNextEntry())
+        {
+            if (!reader.Entry.IsDirectory)
+            {
+                count++;
+            }
+        }
+
+        // Should iterate through all entries, not just the first one
+        Assert.True(count > 1, $"Expected more than 1 entry, but got {count}");
+    }
+
+    [Fact]
+    public void Archive_Iteration_DoesNotBreak_WhenFlushThrows_LZMA()
+    {
+        // Regression test: since 0.41.0, archive iteration would silently break
+        // when the input stream throws NotSupportedException in Flush().
+        // Only the first entry would be returned, then iteration would stop without exception.
+        var path = Path.Combine(TEST_ARCHIVES_PATH, "Zip.lzma.dd.zip");
+        using var fileStream = File.OpenRead(path);
+        using Stream stream = new ThrowOnFlushStream(fileStream);
+        using var reader = ReaderFactory.Open(stream);
+
+        var count = 0;
+        while (reader.MoveToNextEntry())
+        {
+            if (!reader.Entry.IsDirectory)
+            {
+                count++;
+            }
+        }
+
+        // Should iterate through all entries, not just the first one
+        Assert.True(count > 1, $"Expected more than 1 entry, but got {count}");
+    }
 }