Fixes for parallel lzma usage

src/SharpCompress/Archives/IArchiveEntryExtensions.cs

@@ -71,12 +71,16 @@ private async ValueTask WriteToAsync(
                 throw new ExtractionException("Entry is a file directory and cannot be extracted.");
             }
 
+#if SYNC_ONLY
+            using var entryStream = archiveEntry.OpenEntryStream();
+#else
             var entryStream = await archiveEntry
                 .OpenEntryStreamAsync(cancellationToken)
                 .ConfigureAwait(false);
             await using var entryStreamScope = entryStream
                 .DisposeAsyncScope()
                 .ConfigureAwait(false);
+#endif
             var checkedStream = options is null
                 ? entryStream
                 : IEntryExtensions.WrapWithChecksumValidation(archiveEntry, entryStream, options);

src/SharpCompress/Common/EntryStream.cs

@@ -30,18 +30,7 @@ protected override void Dispose(bool disposing)
         _isDisposed = true;
         if (!(_completed || _reader.Cancelled))
         {
-            if (Utility.UseSyncOverAsyncDispose())
-            {
-#pragma warning disable VSTHRD002 // Avoid problematic synchronous waits
-#pragma warning disable CA2012
-                SkipEntryAsync().GetAwaiter().GetResult();
-#pragma warning restore CA2012
-#pragma warning restore VSTHRD002 // Avoid problematic synchronous waits
-            }
-            else
-            {
-                SkipEntry();
-            }
+            SkipEntry();
         }
 
         //Need a safe standard approach to this - it's okay for compression to overreads. Handling needs to be standardised

src/SharpCompress/Common/Tar/TarReadOnlySubStream.cs

@@ -29,18 +29,7 @@ protected override void Dispose(bool disposing)
         _isDisposed = true;
         if (disposing)
         {
-            if (Utility.UseSyncOverAsyncDispose())
-            {
-#pragma warning disable VSTHRD002 // Avoid problematic synchronous waits
-#pragma warning disable CA2012
-                AdvanceToNextHeaderAsync().GetAwaiter().GetResult();
-#pragma warning restore CA2012
-#pragma warning restore VSTHRD002 // Avoid problematic synchronous waits
-            }
-            else
-            {
-                AdvanceToNextHeader();
-            }
+            AdvanceToNextHeader();
         }
         base.Dispose(disposing);
     }

src/SharpCompress/Common/Zip/WinzipAesCryptoStream.cs

@@ -69,28 +69,27 @@ protected override void Dispose(bool disposing)
         _isDisposed = true;
         if (disposing)
         {
-            // Read out last 10 auth bytes - catch exceptions for async-only streams
-            if (Utility.UseSyncOverAsyncDispose())
+            // Read out last 10 auth bytes
+#if LEGACY_DOTNET
+            // Stream has no DisposeAsync on legacy targets, so async flows fall back to this
+            // sync Dispose while the underlying stream may be async-only.
+            var ten = ArrayPool<byte>.Shared.Rent(10);
+            try
             {
-                var ten = ArrayPool<byte>.Shared.Rent(10);
-                try
-                {
 #pragma warning disable VSTHRD002 // Avoid problematic synchronous waits
 #pragma warning disable CA2012
-                    _stream.ReadFullyAsync(ten, 0, 10).GetAwaiter().GetResult();
+                _stream.ReadFullyAsync(ten, 0, 10).GetAwaiter().GetResult();
 #pragma warning restore CA2012
 #pragma warning restore VSTHRD002 // Avoid problematic synchronous waits
-                }
-                finally
-                {
-                    ArrayPool<byte>.Shared.Return(ten);
-                }
             }
-            else
+            finally
             {
-                Span<byte> ten = stackalloc byte[10];
-                _stream.ReadFully(ten);
+                ArrayPool<byte>.Shared.Return(ten);
             }
+#else
+            Span<byte> ten = stackalloc byte[10];
+            _stream.ReadFully(ten);
+#endif
             _stream.Dispose();
         }
         base.Dispose(disposing);

src/SharpCompress/Utility.cs

@@ -23,15 +23,6 @@ internal static partial class Utility
             ? StringComparison.OrdinalIgnoreCase
             : StringComparison.Ordinal;
 
-    public static bool UseSyncOverAsyncDispose()
-    {
-        var useSyncOverAsync = false;
-#if LEGACY_DOTNET
-        useSyncOverAsync = true;
-#endif
-        return useSyncOverAsync;
-    }
-
     private static readonly HashSet<char> invalidChars = new(Path.GetInvalidFileNameChars());
 
     public static ReadOnlyCollection<T> ToReadOnly<T>(this IList<T> items) => new(items);