HawkFile: limit attempts to dearchive to files with extension .zip, .7z, .rar. fixes #2587

src/BizHawk.Client.Common/RomLoader.cs

@@ -604,12 +604,9 @@ namespace BizHawk.Client.Common
 				return false;
 			}
 
-			using var file = new HawkFile(
-				path,
-				nonArchiveExtensions: OpenAdvanced is OpenAdvanced_MAME
-					? new[] { ".zip", ".7z" } // MAME uses these extensions for arcade ROMs, but also accepts all sorts of variations of archives, folders, and files. if we let archive loader handle this, it won't know where to stop, since it'd require MAME's ROM database (which contains ROM names and blob hashes) to look things up, and even then it might be confused by archive/folder structure. so assume the user provides the proper ROM directly, and handle possible errors later
-					: null
-			);
+			bool allowArchives = true;
+			if (OpenAdvanced is OpenAdvanced_MAME) allowArchives = false;
+			using var file = new HawkFile(path, false, allowArchives);
 			if (!file.Exists) return false; // if the provided file doesn't even exist, give up!
 
 			CanonicalFullPath = file.CanonicalFullPath;

src/BizHawk.Client.Common/SharpCompressDearchivalMethod.cs

@@ -1,7 +1,6 @@
-#nullable enable
-
 using System.IO;
 using System.Linq;
+using System.Collections.Generic;
 using BizHawk.Common;
 using SharpCompress.Archives;
 
@@ -30,6 +29,12 @@ namespace BizHawk.Client.Common
 
 		public SharpCompressArchiveFile Construct(string path) => new SharpCompressArchiveFile(path);
 
-		public static readonly SharpCompressDearchivalMethod Instance = new SharpCompressDearchivalMethod();
+		public static readonly SharpCompressDearchivalMethod Instance = new SharpCompressDearchivalMethod();
+
+		//don't try any .tar.* formats, they don't work
+		//don't try .gz, it's illogical (gz contains no useful archive directory information. we would need to synthesize some.)
+		static readonly IReadOnlyCollection<string> archiveExts = new[] { ".zip", ".7z", ".rar" };
+
+		public IReadOnlyCollection<string> AllowedArchiveExtensions { get { return archiveExts; } }
 	}
 }

src/BizHawk.Common/HawkFile/HawkFile.cs

@@ -71,12 +71,7 @@ namespace BizHawk.Common
 
 		/// <summary>Makes a new HawkFile based on the provided path.</summary>
 		/// <param name="delayIOAndDearchive">Pass <see langword="true"/> to only populate a few fields (those that can be computed from the string <paramref name="path"/>), which is less computationally expensive.</param>
-		/// <param name="nonArchiveExtensions">
-		/// These file extensions are assumed to not be archives. Include the leading period in each, and use lowercase.<br/>
-		/// Does not apply when <paramref name="delayIOAndDearchive"/> is <see langword="true"/>.<br/>
-		/// If <see langword="null"/> is passed (the default), uses <see cref="CommonNonArchiveExtensions"/> which should mitigate false positives caused by weak archive detection signatures.
-		/// </param>
-		public HawkFile([HawkFilePath] string path, bool delayIOAndDearchive = false, IReadOnlyCollection<string>? nonArchiveExtensions = null)
+		public HawkFile([HawkFilePath] string path, bool delayIOAndDearchive = false, bool allowArchives = true)
 		{
 			if (delayIOAndDearchive)
 			{
@@ -97,23 +92,29 @@ namespace BizHawk.Common
 			Exists = _rootExists = !string.IsNullOrEmpty(path) && new FileInfo(path).Exists;
 			if (!_rootExists) return;
 
-			if (DearchivalMethod != null
-				&& !(nonArchiveExtensions ?? CommonNonArchiveExtensions).Contains(Path.GetExtension(path).ToLowerInvariant())
-				&& DearchivalMethod.CheckSignature(path, out _, out _))
+			if (DearchivalMethod != null && allowArchives)
 			{
-				_extractor = DearchivalMethod.Construct(path);
-				try
+				var ext = Path.GetExtension(path).ToLowerInvariant();
+				if (DearchivalMethod.AllowedArchiveExtensions.Contains(ext))
 				{
-					_archiveItems = _extractor.Scan();
-					IsArchive = true;
-				}
-				catch
-				{
-					_archiveItems = null;
-					_extractor.Dispose();
-					_extractor = null;
+					if (DearchivalMethod.CheckSignature(path, out _, out _))
+					{
+						_extractor = DearchivalMethod.Construct(path);
+						try
+						{
+							_archiveItems = _extractor.Scan();
+							IsArchive = true;
+						}
+						catch
+						{
+							_archiveItems = null;
+							_extractor.Dispose();
+							_extractor = null;
+						}
+					}
 				}
 			}
+
 			if (_extractor == null)
 			{
 				_rootStream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
@@ -276,12 +277,9 @@ namespace BizHawk.Common
 		/// <summary>Set this with an instance which can construct archive handlers as necessary for archive handling.</summary>
 		public static IFileDearchivalMethod<IHawkArchiveFile>? DearchivalMethod;
 
-		public static readonly IReadOnlyCollection<string> CommonNonArchiveExtensions = new[] { ".smc", ".sfc", ".dll" };
-
 		[return: HawkFilePath]
 		private static string MakeCanonicalName(string root, string? member) => member == null ? root : $"{root}|{member}";
 
-
 		/// <returns>path / member path pair iff <paramref name="path"/> contains <c>'|'</c>, <see langword="null"/> otherwise</returns>
 		private static (string, string)? SplitArchiveMemberPath([HawkFilePath] string path)
 		{

src/BizHawk.Common/HawkFile/IFileDearchivalMethod.cs

@@ -1,3 +1,5 @@
+using System.Collections.Generic;
+
 namespace BizHawk.Common
 {
 	/// <summary>Used by <see cref="HawkFile"/> to delegate archive management.</summary>
@@ -6,6 +8,8 @@ namespace BizHawk.Common
 		/// <remarks>TODO could this receive a <see cref="HawkFile"/> itself? possibly handy, in very clever scenarios of mounting fake files</remarks>
 		bool CheckSignature(string fileName, out int offset, out bool isExecutable);
 
+		IReadOnlyCollection<string> AllowedArchiveExtensions { get; }
+
 		T Construct(string path);
 	}
 }