Fix EntryStream.Dispose() throwing NotSupportedException on non-seekable streams

src/SharpCompress/Common/EntryStream.cs

@@ -79,11 +79,25 @@ protected override void Dispose(bool disposing)
         {
             if (ss.BaseStream() is SharpCompress.Compressors.Deflate.DeflateStream deflateStream)
             {
-                deflateStream.Flush(); //Deflate over reads. Knock it back
+                try
+                {
+                    deflateStream.Flush(); //Deflate over reads. Knock it back
+                }
+                catch (NotSupportedException)
+                {
+                    // Ignore: underlying stream does not support required operations for Flush
+                }
             }
             else if (ss.BaseStream() is SharpCompress.Compressors.LZMA.LzmaStream lzmaStream)
             {
-                lzmaStream.Flush(); //Lzma over reads. Knock it back
+                try
+                {
+                    lzmaStream.Flush(); //Lzma over reads. Knock it back
+                }
+                catch (NotSupportedException)
+                {
+                    // Ignore: underlying stream does not support required operations for Flush
+                }
             }
         }
 #if DEBUG_STREAMS
@@ -111,11 +125,25 @@ public override async ValueTask DisposeAsync()
         {
             if (ss.BaseStream() is SharpCompress.Compressors.Deflate.DeflateStream deflateStream)
             {
-                await deflateStream.FlushAsync().ConfigureAwait(false);
+                try
+                {
+                    await deflateStream.FlushAsync().ConfigureAwait(false);
+                }
+                catch (NotSupportedException)
+                {
+                    // Ignore: underlying stream does not support required operations for Flush
+                }
             }
             else if (ss.BaseStream() is SharpCompress.Compressors.LZMA.LzmaStream lzmaStream)
             {
-                await lzmaStream.FlushAsync().ConfigureAwait(false);
+                try
+                {
+                    await lzmaStream.FlushAsync().ConfigureAwait(false);
+                }
+                catch (NotSupportedException)
+                {
+                    // Ignore: underlying stream does not support required operations for Flush
+                }
             }
         }
 #if DEBUG_STREAMS

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>$(DefineConstants);WINDOWS</DefineConstants>
   </PropertyGroup>
@@ -24,7 +27,7 @@
     <PackageReference Include="xunit.runner.visualstudio" />
     <PackageReference Include="xunit" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(VersionlessImplicitFrameworkDefine)' != 'NETFRAMEWORK' ">
+  <ItemGroup Condition="$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::Linux)))">
     <PackageReference Include="Mono.Posix.NETStandard" />
   </ItemGroup>
 </Project>

tests/SharpCompress.Test/Zip/ZipReaderAsyncTests.cs

@@ -283,4 +283,58 @@ await reader.WriteEntryToDirectoryAsync(
         }
         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));
+        await using var reader = ReaderFactory.OpenAsyncReader(new AsyncOnlyStream(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));
+        await using var reader = ReaderFactory.OpenAsyncReader(new AsyncOnlyStream(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
+            }
+        }
+    }
 }

tests/SharpCompress.Test/Zip/ZipReaderTests.cs

@@ -444,4 +444,50 @@ public void ZipReader_Returns_Same_Entries_As_ZipArchive()
             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.OpenReader(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.OpenReader(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
+            }
+        }
+    }
 }