Properly use the virtual filesystem for map loading and saving.

OpenRA.Game/FileSystem/FileSystem.cs

@@ -64,6 +64,32 @@ namespace OpenRA.FileSystem
 			return new Folder(Platform.ResolvePath(filename));
 		}
 
+		public IReadOnlyPackage OpenPackage(string filename, IReadOnlyPackage parent)
+		{
+			// HACK: limit support to zip and folder until we generalize the PackageLoader support
+			if (parent is Folder)
+			{
+				var path = Path.Combine(parent.Name, filename);
+
+				// HACK: work around SharpZipLib's lack of support for writing to in-memory files
+				if (filename.EndsWith(".zip", StringComparison.InvariantCultureIgnoreCase))
+					return new ZipFile(this, path);
+				if (filename.EndsWith(".oramap", StringComparison.InvariantCultureIgnoreCase))
+					return new ZipFile(this, path);
+
+				var subFolder = Platform.ResolvePath(path);
+				if (Directory.Exists(subFolder))
+					return new Folder(subFolder);
+			}
+
+			if (filename.EndsWith(".zip", StringComparison.InvariantCultureIgnoreCase))
+				return new ZipFile(this, filename, parent.GetStream(filename));
+			if (filename.EndsWith(".oramap", StringComparison.InvariantCultureIgnoreCase))
+				return new ZipFile(this, filename, parent.GetStream(filename));
+
+			return null;
+		}
+
 		public IReadWritePackage OpenWritablePackage(string filename)
 		{
 			if (filename.EndsWith(".zip", StringComparison.InvariantCultureIgnoreCase))

OpenRA.Game/FileSystem/Folder.cs

@@ -33,6 +33,8 @@ namespace OpenRA.FileSystem
 			{
 				foreach (var filename in Directory.GetFiles(path, "*", SearchOption.TopDirectoryOnly))
 					yield return Path.GetFileName(filename);
+				foreach (var filename in Directory.GetDirectories(path))
+					yield return Path.GetFileName(filename);
 			}
 		}
 
@@ -59,7 +61,12 @@ namespace OpenRA.FileSystem
 
 		public void Delete(string filename)
 		{
-			var filePath = Path.Combine(path, filename);
+			// HACK: ZipFiles can't be loaded as read-write from a stream, so we are
+			// forced to bypass the parent package and load them with their full path
+			// in FileSystem.OpenPackage.  Their internal name therefore contains the
+			// full parent path too.  We need to be careful to not add a second path
+			// prefix to these hacked packages.
+			var filePath = filename.StartsWith(path) ? filename : Path.Combine(path, filename);
 			if (Directory.Exists(filePath))
 				Directory.Delete(filePath, true);
 			else if (File.Exists(filePath))

OpenRA.Game/FileSystem/ZipFile.cs

@@ -27,6 +27,16 @@ namespace OpenRA.FileSystem
 			ZipConstants.DefaultCodePage = Encoding.UTF8.CodePage;
 		}
 
+		public ZipFile(FileSystem context, string filename, Stream stream, bool createOrClearContents = false)
+		{
+			Name = filename;
+
+			if (createOrClearContents)
+				pkg = SZipFile.Create(stream);
+			else
+				pkg = new SZipFile(stream);
+		}
+
 		public ZipFile(IReadOnlyFileSystem context, string filename, bool createOrClearContents = false)
 		{
 			Name = filename;