From e1900cd3423ce8b05d8b39dbf26e0aaa32ccdc2e Mon Sep 17 00:00:00 2001
From: DubbleClick <m@pyc.ac>
Date: Wed, 15 Apr 2026 22:22:32 +0700
Subject: [PATCH] fix edge case in tpf unscrambling logic

---
 TpfConvert/src/ModfileLoader_TpfReader.ixx | 2 +-
 modules/ModfileLoader_TpfReader.ixx        | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/TpfConvert/src/ModfileLoader_TpfReader.ixx b/TpfConvert/src/ModfileLoader_TpfReader.ixx
index 5c14a76..59b9b35 100644
--- a/TpfConvert/src/ModfileLoader_TpfReader.ixx
+++ b/TpfConvert/src/ModfileLoader_TpfReader.ixx
@@ -46,7 +46,7 @@ private:
 
     [[nodiscard]] char XOR(const char b, const long position) const
     {
-        if (position > line_length - 4) {
+        if (position >= (line_length / 4) * 4) {
             return b ^ TPF_XOREven;
         }
 
diff --git a/modules/ModfileLoader_TpfReader.ixx b/modules/ModfileLoader_TpfReader.ixx
index 1c7e728..81410d3 100644
--- a/modules/ModfileLoader_TpfReader.ixx
+++ b/modules/ModfileLoader_TpfReader.ixx
@@ -46,7 +46,7 @@ private:
 
     [[nodiscard]] char XOR(const char b, const long position) const
     {
-        if (position > line_length - 4) {
+        if (position >= (line_length / 4) * 4) {
             return b ^ TPF_XOREven;
         }