Fix mysteriously deleted issue #3197: Skip file formats that currentl…

…y can only be loaded from a file when dealing with a file from a bundle or package.

ICSharpCode.Decompiler/Metadata/WebCilFile.cs

@@ -47,9 +47,14 @@ private WebCilFile(string fileName, long webcilOffset, long metadataOffset, Memo
 			this.WasmSections = wasmSections;
 		}
 
-		public static WebCilFile? FromStream(string fileName, MetadataReaderOptions metadataOptions = MetadataReaderOptions.Default)
+		public static WebCilFile? FromFile(string fileName, MetadataReaderOptions metadataOptions = MetadataReaderOptions.Default)
 		{
-			using var memoryMappedFile = MemoryMappedFile.CreateFromFile(fileName, FileMode.Open, null, 0, MemoryMappedFileAccess.Read);
+			using var memoryMappedFile = TryCreateFromFile(fileName);
+			if (memoryMappedFile == null)
+			{
+				return null;
+			}
+
 			var view = memoryMappedFile.CreateViewAccessor(0, 0, MemoryMappedFileAccess.Read);
 			try
 			{
@@ -124,6 +129,18 @@ private WebCilFile(string fileName, long webcilOffset, long metadataOffset, Memo
 			{
 				view?.Dispose();
 			}
+
+			static MemoryMappedFile? TryCreateFromFile(string fileName)
+			{
+				try
+				{
+					return MemoryMappedFile.CreateFromFile(fileName, FileMode.Open, null, 0, MemoryMappedFileAccess.Read);
+				}
+				catch (IOException)
+				{
+					return null;
+				}
+			}
 		}
 
 		static unsafe bool TryReadWebCilSegment(BinaryReader reader, out WebcilHeader webcilHeader, out long metadataOffset, out long webcilOffset, [NotNullWhen(true)] out SectionHeader[]? sectionHeaders)

ICSharpCode.ILSpyX/FileLoaders/ArchiveFileLoader.cs

@@ -23,8 +23,13 @@ namespace ICSharpCode.ILSpyX.FileLoaders
 {
 	public sealed class ArchiveFileLoader : IFileLoader
 	{
-		public Task<LoadResult?> Load(string fileName, Stream stream, FileLoadSettings settings)
+		public Task<LoadResult?> Load(string fileName, Stream stream, FileLoadContext settings)
 		{
+			if (settings.ParentBundle != null)
+			{
+				return Task.FromResult<LoadResult?>(null);
+			}
+
 			try
 			{
 				var zip = LoadedPackage.FromZipFile(fileName);

ICSharpCode.ILSpyX/FileLoaders/BundleFileLoader.cs

@@ -23,8 +23,13 @@ namespace ICSharpCode.ILSpyX.FileLoaders
 {
 	public sealed class BundleFileLoader : IFileLoader
 	{
-		public Task<LoadResult?> Load(string fileName, Stream stream, FileLoadSettings settings)
+		public Task<LoadResult?> Load(string fileName, Stream stream, FileLoadContext settings)
 		{
+			if (settings.ParentBundle != null)
+			{
+				return Task.FromResult<LoadResult?>(null);
+			}
+
 			var bundle = LoadedPackage.FromBundle(fileName);
 			var result = bundle != null ? new LoadResult { Package = bundle } : null;
 			return Task.FromResult(result);

ICSharpCode.ILSpyX/FileLoaders/LoadResult.cs

@@ -29,12 +29,14 @@ public sealed class LoadResult
 		public MetadataFile? MetadataFile { get; init; }
 		public Exception? FileLoadException { get; init; }
 		public LoadedPackage? Package { get; init; }
+
+		public bool IsSuccess => FileLoadException == null;
 	}
 
-	public record FileLoadSettings(bool ApplyWinRTProjections);
+	public record FileLoadContext(bool ApplyWinRTProjections, LoadedAssembly? ParentBundle);
 
 	public interface IFileLoader
 	{
-		Task<LoadResult?> Load(string fileName, Stream stream, FileLoadSettings settings);
+		Task<LoadResult?> Load(string fileName, Stream stream, FileLoadContext context);
 	}
 }

ICSharpCode.ILSpyX/FileLoaders/MetadataFileLoader.cs

@@ -29,7 +29,7 @@ namespace ICSharpCode.ILSpyX.FileLoaders
 {
 	public sealed class MetadataFileLoader : IFileLoader
 	{
-		public Task<LoadResult?> Load(string fileName, Stream stream, FileLoadSettings settings)
+		public Task<LoadResult?> Load(string fileName, Stream stream, FileLoadContext settings)
 		{
 			try
 			{

ICSharpCode.ILSpyX/FileLoaders/WebCilFileLoader.cs

@@ -26,13 +26,18 @@ namespace ICSharpCode.ILSpyX.FileLoaders
 {
 	public sealed class WebCilFileLoader : IFileLoader
 	{
-		public Task<LoadResult?> Load(string fileName, Stream stream, FileLoadSettings settings)
+		public Task<LoadResult?> Load(string fileName, Stream stream, FileLoadContext settings)
 		{
+			if (settings.ParentBundle != null)
+			{
+				return Task.FromResult<LoadResult?>(null);
+			}
+
 			MetadataReaderOptions options = settings.ApplyWinRTProjections
-						? MetadataReaderOptions.ApplyWindowsRuntimeProjections
-						: MetadataReaderOptions.None;
+							? MetadataReaderOptions.ApplyWindowsRuntimeProjections
+							: MetadataReaderOptions.None;
 
-			var wasm = WebCilFile.FromStream(fileName, options);
+			var wasm = WebCilFile.FromFile(fileName, options);
 			var result = wasm != null ? new LoadResult { MetadataFile = wasm } : null;
 			return Task.FromResult(result);
 		}

ICSharpCode.ILSpyX/FileLoaders/XamarinCompressedFileLoader.cs

@@ -31,7 +31,7 @@ namespace ICSharpCode.ILSpyX.FileLoaders
 {
 	public sealed class XamarinCompressedFileLoader : IFileLoader
 	{
-		public async Task<LoadResult?> Load(string fileName, Stream stream, FileLoadSettings settings)
+		public async Task<LoadResult?> Load(string fileName, Stream stream, FileLoadContext context)
 		{
 			const uint CompressedDataMagic = 0x5A4C4158; // Magic used for Xamarin compressed module header ('XALZ', little-endian)
 			using var fileReader = new BinaryReader(stream, Encoding.UTF8, leaveOpen: true);
@@ -54,7 +54,7 @@ public sealed class XamarinCompressedFileLoader : IFileLoader
 				// Load module from decompressed data buffer
 				using (var uncompressedStream = new MemoryStream(dst, writable: false))
 				{
-					MetadataReaderOptions options = settings.ApplyWinRTProjections
+					MetadataReaderOptions options = context.ApplyWinRTProjections
 						? MetadataReaderOptions.ApplyWindowsRuntimeProjections
 						: MetadataReaderOptions.None;
 

ICSharpCode.ILSpyX/LoadedAssembly.cs

@@ -314,24 +314,41 @@ public bool IsLoadedAsValidAssembly {
 		async Task<LoadResult> LoadAsync(Task<Stream?>? streamTask)
 		{
 			using var stream = await PrepareStream();
-			FileLoadSettings settings = new FileLoadSettings(applyWinRTProjections);
+			FileLoadContext settings = new FileLoadContext(applyWinRTProjections, ParentBundle);
 
 			LoadResult? result = null;
 
 			if (fileLoaders != null)
 			{
 				foreach (var loader in fileLoaders.RegisteredLoaders)
 				{
+					// In each iteration any of the following things may happen:
+					// Load returns null because the loader is unable to handle the file, we simply continue without recording the result.
+					// Load returns a non-null value that is either a valid result or an exception:
+					// - if it's a success, we use that and end the loop,
+					// - if it's an error, we remember the error, discarding any previous errors.
+					// Load throws an exception, remember the error, discarding any previous errors.
 					stream.Position = 0;
-					result = await loader.Load(fileName, stream, settings).ConfigureAwait(false);
-					if (result != null)
+					try
 					{
-						break;
+						var nextResult = await loader.Load(fileName, stream, settings).ConfigureAwait(false);
+						if (nextResult != null)
+						{
+							result = nextResult;
+							if (result.IsSuccess)
+							{
+								break;
+							}
+						}
+					}
+					catch (Exception ex)
+					{
+						result = new LoadResult { FileLoadException = ex };
 					}
 				}
 			}
 
-			if (result == null)
+			if (result?.IsSuccess != true)
 			{
 				stream.Position = 0;
 				try