From 8ef3838beb072eebed5465e501640a29ed407a35 Mon Sep 17 00:00:00 2001
From: Kim Kulling <kimkulling@users.noreply.github.com>
Date: Thu, 28 Aug 2025 11:48:38 +0200
Subject: [PATCH] FBX: Fix offset calculation by adding cursor check (#6337)

- closes https://github.com/assimp/assimp/issues/6336
---
 code/AssetLib/FBX/FBXBinaryTokenizer.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/code/AssetLib/FBX/FBXBinaryTokenizer.cpp b/code/AssetLib/FBX/FBXBinaryTokenizer.cpp
index 3f56006d2..a0c762220 100644
--- a/code/AssetLib/FBX/FBXBinaryTokenizer.cpp
+++ b/code/AssetLib/FBX/FBXBinaryTokenizer.cpp
@@ -91,7 +91,9 @@ AI_WONT_RETURN void TokenizeError(const std::string& message, size_t offset)
 
 // ------------------------------------------------------------------------------------------------
 size_t Offset(const char* begin, const char* cursor) {
-    ai_assert(begin <= cursor);
+    if (begin > cursor) {
+		return 0;
+	}
 
     return cursor - begin;
 }