From 31e24ca9bd800d151d98f6a426bdd96b0dc6a886 Mon Sep 17 00:00:00 2001
From: blueloveTH <blueloveTH@foxmail.com>
Date: Sat, 12 Aug 2023 22:50:36 +0800
Subject: [PATCH] fix a bug

---
 3rd/box2d/include/box2d_bindings.hpp | 4 +++-
 3rd/box2d/src/box2d_Body.cpp         | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/3rd/box2d/include/box2d_bindings.hpp b/3rd/box2d/include/box2d_bindings.hpp
index 502a5d74..4f455f8b 100644
--- a/3rd/box2d/include/box2d_bindings.hpp
+++ b/3rd/box2d/include/box2d_bindings.hpp
@@ -73,7 +73,9 @@ struct PyBody{
     PyBody(): body(nullptr), fixture(nullptr), node_like(nullptr){}
 
     void _gc_mark() {
-        PK_OBJ_MARK(node_like);
+        if(node_like != nullptr){
+            PK_OBJ_MARK(node_like);
+        }
     }
 
     PyBody& _() { return *this; }
diff --git a/3rd/box2d/src/box2d_Body.cpp b/3rd/box2d/src/box2d_Body.cpp
index ea1df5eb..2797913c 100644
--- a/3rd/box2d/src/box2d_Body.cpp
+++ b/3rd/box2d/src/box2d_Body.cpp
@@ -128,7 +128,7 @@ void PyBody::_register(VM* vm, PyObject* mod, PyObject* type){
 
     // destroy
     vm->bind(type, "destroy(self)", [](VM* vm, ArgsView args){
-        PyBody& body = CAST(PyBody&, args[1]);
+        PyBody& body = CAST(PyBody&, args[0]);
         body.body->GetWorld()->DestroyBody(body.body);
         body.body = nullptr;
         body.fixture = nullptr;