From ab4bb4cca3dc570b438f11a12ccda7bf2d58cd2b Mon Sep 17 00:00:00 2001
From: Deterous <138427222+Deterous@users.noreply.github.com>
Date: Mon, 20 Apr 2026 11:13:01 +0900
Subject: [PATCH] Fix XDVDFS bug (#88)

* Fix XDVDFS bug

* Move check and seek earlier
---
 SabreTools.Serialization.Readers/XDVDFS.cs | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/SabreTools.Serialization.Readers/XDVDFS.cs b/SabreTools.Serialization.Readers/XDVDFS.cs
index 1127f363..fe09b63b 100644
--- a/SabreTools.Serialization.Readers/XDVDFS.cs
+++ b/SabreTools.Serialization.Readers/XDVDFS.cs
@@ -146,6 +146,10 @@ namespace SabreTools.Serialization.Readers
 
             var obj = new Dictionary<uint, DirectoryDescriptor>();
 
+            // Seek to current descriptor
+            data.SeekIfPossible(initialOffset + (((long)offset) * Constants.SectorSize), SeekOrigin.Begin);
+
+            // Parse current descriptor
             var dd = ParseDirectoryDescriptor(data, initialOffset, offset, size);
             if (dd is null)
                 return null;
@@ -161,13 +165,6 @@ namespace SabreTools.Serialization.Readers
                     if (obj.ContainsKey(dr.ExtentOffset))
                         continue;
 
-                    // Ensure offset is valid
-                    if ((((long)dr.ExtentOffset) * Constants.SectorSize) + size > data.Length)
-                        return null;
-
-                    // Seek to child descriptor
-                    data.SeekIfPossible(initialOffset + (((long)dr.ExtentOffset) * Constants.SectorSize), SeekOrigin.Begin);
-
                     // Get all descriptors from child
                     var descriptors = ParseDirectoryDescriptors(data, initialOffset, dr.ExtentOffset, dr.ExtentSize);
                     if (descriptors is null)