From e7aee30bbcbbaff25a2a377abaa3e4fc2b5d4aa6 Mon Sep 17 00:00:00 2001
From: Henry Schreiner <henryschreineriii@gmail.com>
Date: Fri, 15 Oct 2021 17:34:05 -0400
Subject: [PATCH] fix: use PyFrame_GetCode on Python 3.9+

---
 include/pybind11/pybind11.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h
index 285f3b18cb7..0d70c3bbab2 100644
--- a/include/pybind11/pybind11.h
+++ b/include/pybind11/pybind11.h
@@ -2326,6 +2326,28 @@ inline function get_type_override(const void *this_ptr, const type_info *this_ty
     /* Don't call dispatch code if invoked from overridden function.
        Unfortunately this doesn't work on PyPy. */
 #if !defined(PYPY_VERSION)
+
+#if PY_VERSION_HEX >= 0x03090000
+    PyFrameObject *frame = PyThreadState_GetFrame(PyThreadState_Get());
+    if (frame != nullptr) {
+        PyCodeObject *code = PyFrame_GetCode(frame);
+        if ((std::string) str(code->co_name) == name && code->co_argcount > 0) {
+            PyObject* locals = PyEval_GetLocals();
+            if (locals != nullptr) {
+                PyObject *self_caller = dict_getitem(
+                    locals, PyTuple_GET_ITEM(code->co_varnames, 0)
+                );
+                if (self_caller == self.ptr()) {
+                    Py_DECREF(code);
+                    Py_DECREF(frame);
+                    return function();
+                }
+            }
+        }
+        Py_DECREF(code);
+        Py_DECREF(frame);
+    }
+#else
     PyFrameObject *frame = PyThreadState_Get()->frame;
     if (frame != nullptr && (std::string) str(frame->f_code->co_name) == name
         && frame->f_code->co_argcount > 0) {
@@ -2335,6 +2357,8 @@ inline function get_type_override(const void *this_ptr, const type_info *this_ty
         if (self_caller == self.ptr())
             return function();
     }
+#endif
+
 #else
     /* PyPy currently doesn't provide a detailed cpyext emulation of
        frame objects, so we have to emulate this using Python. This