From cce0ae24ffe8a7c366c6908a8ab8b5d703d20e29 Mon Sep 17 00:00:00 2001
From: Jason Matthew Suhari <jasonmatthewsuhari@gmail.com>
Date: Fri, 20 Mar 2026 12:18:57 +0800
Subject: [PATCH] fix: capture stack checkpoint before pushing args in
 operator() (#469)

---
 include/pybind11/internal/function.h | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/pybind11/internal/function.h b/include/pybind11/internal/function.h
index 2c84e756..c1c69dff 100644
--- a/include/pybind11/internal/function.h
+++ b/include/pybind11/internal/function.h
@@ -70,6 +70,7 @@ args_proxy interface<Derived>::operator* () const {
 template <typename Derived>
 template <return_value_policy policy, typename... Args>
 object interface<Derived>::operator() (Args&&... args) const {
+    py_StackRef p0 = py_peek(0); // checkpoint before pushing so py_clearexc can safely rewind
     py_push(ptr());
     py_pushnil();
 
@@ -108,7 +109,13 @@ object interface<Derived>::operator() (Args&&... args) const {
 
     (foreach(std::forward<Args>(args)), ...);
 
-    raise_call<py_vectorcall>(argc, kwargsc);
+    if(!py_vectorcall(argc, kwargsc)) {
+        py_matchexc(tp_Exception);
+        object e = object::from_ret();
+        auto what = py_formatexc();
+        py_clearexc(p0);
+        throw python_error(what, std::move(e));
+    }
 
     return object::from_ret();
 }