From 7ddcf45ec5dabc43b1ad7b6a91d219bc9f8225c6 Mon Sep 17 00:00:00 2001
From: David Hewitt <1939362+davidhewitt@users.noreply.github.com>
Date: Sun, 18 Oct 2020 18:36:31 +0100
Subject: [PATCH] Fix lifetime soundness in freelist

---
 pyo3-derive-backend/src/pyclass.rs | 2 +-
 src/freelist.rs                    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/pyo3-derive-backend/src/pyclass.rs b/pyo3-derive-backend/src/pyclass.rs
index 558a6f6e..032935d5 100644
--- a/pyo3-derive-backend/src/pyclass.rs
+++ b/pyo3-derive-backend/src/pyclass.rs
@@ -267,7 +267,7 @@ fn impl_class(
             quote! {
                 impl pyo3::freelist::PyClassWithFreeList for #cls {
                     #[inline]
-                    fn get_free_list(_py: pyo3::Python) -> &'static mut pyo3::freelist::FreeList<*mut pyo3::ffi::PyObject> {
+                    fn get_free_list(_py: pyo3::Python) -> &mut pyo3::freelist::FreeList<*mut pyo3::ffi::PyObject> {
                         static mut FREELIST: *mut pyo3::freelist::FreeList<*mut pyo3::ffi::PyObject> = 0 as *mut _;
                         unsafe {
                             if FREELIST.is_null() {
diff --git a/src/freelist.rs b/src/freelist.rs
index 65331773..5b56c337 100644
--- a/src/freelist.rs
+++ b/src/freelist.rs
@@ -12,7 +12,7 @@ use std::os::raw::c_void;
 /// The performance improvement applies to types that are often created and deleted in a row,
 /// so that they can benefit from a freelist.
 pub trait PyClassWithFreeList {
-    fn get_free_list(py: Python) -> &'static mut FreeList<*mut ffi::PyObject>;
+    fn get_free_list(py: Python) -> &mut FreeList<*mut ffi::PyObject>;
 }
 
 pub enum Slot<T> {