[3.12] gh-118997: Fix _Py_ClearImmortal() assertion (#119001)

vstinner · web-flow · commit bd1e9509a447 · 2024-05-18T16:56:27.000-04:00
Fix _Py_ClearImmortal() assertion: use _Py_IsImmortal() to tolerate
reference count lower than _Py_IMMORTAL_REFCNT. Fix the assertion for
the stable ABI, when a C extension is built with Python 3.11 or
lower.
diff --git a/Include/internal/pycore_object.h b/Include/internal/pycore_object.h
@@ -80,7 +80,7 @@ static inline void _Py_SetImmortal(PyObject *op)
 static inline void _Py_ClearImmortal(PyObject *op)
 {
     if (op) {
-        assert(op->ob_refcnt == _Py_IMMORTAL_REFCNT);
+        assert(_Py_IsImmortal(op));
         op->ob_refcnt = 1;
         Py_DECREF(op);
     }
diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-05-13-16-00-05.gh-issue-118997.GWqWdt.rst b/Misc/NEWS.d/next/Core and Builtins/2024-05-13-16-00-05.gh-issue-118997.GWqWdt.rst
@@ -0,0 +1,4 @@
+Fix _Py_ClearImmortal() assertion: use _Py_IsImmortal() to tolerate
+reference count lower than _Py_IMMORTAL_REFCNT. Fix the assertion for the
+stable ABI, when a C extension is built with Python 3.11 or lower. Patch by
+Victor Stinner.

Original file line number	Diff line number	Diff line change
`@@ -80,7 +80,7 @@ static inline void _Py_SetImmortal(PyObject *op)`
`80`	`80`	`static inline void _Py_ClearImmortal(PyObject *op)`
`81`	`81`	`{`
`82`	`82`	`if (op) {`
`83`		`- assert(op->ob_refcnt == _Py_IMMORTAL_REFCNT);`
	`83`	`+ assert(_Py_IsImmortal(op));`
`84`	`84`	`op->ob_refcnt = 1;`
`85`	`85`	`Py_DECREF(op);`
`86`	`86`	`}`