From ec564e1cff25e94422e8e45a8943f379c82548ee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 1 Sep 2025 10:21:39 +0200
Subject: [PATCH] gh-116946: fully implement GC protocol for `bz2` objects
 (GH-138266) (cherry picked from commit
 9be91f6a20ed2fd9b491c3e779dc45c7392f60ca)
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Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 Modules/_bz2module.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/Modules/_bz2module.c b/Modules/_bz2module.c
index 9e85e0de42cd8d..f0f64b79d648eb 100644
--- a/Modules/_bz2module.c
+++ b/Modules/_bz2module.c
@@ -381,13 +381,14 @@ _bz2_BZ2Compressor_impl(PyTypeObject *type, int compresslevel)
 static void
 BZ2Compressor_dealloc(PyObject *op)
 {
+    PyTypeObject *tp = Py_TYPE(op);
+    PyObject_GC_UnTrack(op);
     BZ2Compressor *self = _BZ2Compressor_CAST(op);
     BZ2_bzCompressEnd(&self->bzs);
     if (self->lock != NULL) {
         PyThread_free_lock(self->lock);
     }
-    PyTypeObject *tp = Py_TYPE(self);
-    tp->tp_free((PyObject *)self);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
@@ -420,7 +421,7 @@ static PyType_Spec bz2_compressor_type_spec = {
     // bz2_compressor_type_spec does not have Py_TPFLAGS_BASETYPE flag
     // which prevents to create a subclass.
     // So calling PyType_GetModuleState() in this file is always safe.
-    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE),
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_HAVE_GC),
     .slots = bz2_compressor_type_slots,
 };
 
@@ -686,9 +687,11 @@ _bz2_BZ2Decompressor_impl(PyTypeObject *type)
 static void
 BZ2Decompressor_dealloc(PyObject *op)
 {
+    PyTypeObject *tp = Py_TYPE(op);
+    PyObject_GC_UnTrack(op);
     BZ2Decompressor *self = _BZ2Decompressor_CAST(op);
 
-    if(self->input_buffer != NULL) {
+    if (self->input_buffer != NULL) {
         PyMem_Free(self->input_buffer);
     }
     BZ2_bzDecompressEnd(&self->bzs);
@@ -696,9 +699,7 @@ BZ2Decompressor_dealloc(PyObject *op)
     if (self->lock != NULL) {
         PyThread_free_lock(self->lock);
     }
-
-    PyTypeObject *tp = Py_TYPE(self);
-    tp->tp_free((PyObject *)self);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
@@ -750,7 +751,7 @@ static PyType_Spec bz2_decompressor_type_spec = {
     // bz2_decompressor_type_spec does not have Py_TPFLAGS_BASETYPE flag
     // which prevents to create a subclass.
     // So calling PyType_GetModuleState() in this file is always safe.
-    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE),
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_HAVE_GC),
     .slots = bz2_decompressor_type_slots,
 };