From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Mon, 2 Mar 2026 21:31:46 +0000 (+0100)
Subject: [3.13] gh-143880: Fix data race in `functools.partial` in free threading build (GH... 
X-Git-Tag: v3.13.13~140
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=fb340275c4246df8355a5641b64acdba5cd38ed6;p=thirdparty%2FPython%2Fcpython.git

[3.13] gh-143880: Fix data race in `functools.partial` in free threading build (GH-143882) (#145435)

Co-authored-by: Sam Gross <colesbury@gmail.com>
---

diff --git a/Misc/NEWS.d/next/Library/2026-01-15-13-03-22.gh-issue-143880.sWoLsf.rst b/Misc/NEWS.d/next/Library/2026-01-15-13-03-22.gh-issue-143880.sWoLsf.rst
new file mode 100644
index 000000000000..b77f86e5eb8f
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-01-15-13-03-22.gh-issue-143880.sWoLsf.rst
@@ -0,0 +1 @@
+Fix data race in :func:`functools.partial` in the :term:`free threading` build.
diff --git a/Modules/_functoolsmodule.c b/Modules/_functoolsmodule.c
index cbbba322a182..40c573b3fdf7 100644
--- a/Modules/_functoolsmodule.c
+++ b/Modules/_functoolsmodule.c
@@ -220,7 +220,9 @@ partial_vectorcall_fallback(PyThreadState *tstate, partialobject *pto,
                             PyObject *const *args, size_t nargsf,
                             PyObject *kwnames)
 {
+#ifndef Py_GIL_DISABLED
     pto->vectorcall = NULL;
+#endif
     Py_ssize_t nargs = PyVectorcall_NARGS(nargsf);
     return _PyObject_MakeTpCall(tstate, (PyObject *)pto,
                                 args, nargs, kwnames);