From cabb466057c53d1ff065384ff86c8a98719f3bc2 Mon Sep 17 00:00:00 2001
From: Neil Schemenauer <nas@arctrix.com>
Date: Mon, 13 Oct 2025 20:59:57 -0700
Subject: [PATCH] Use strong reference APIs.

For the free-threaded build, it is not safe use borrowed references.
Another thread could deallocate the object and cause the reference to
become invalid.  Replace API calls that borrow references with strong
reference APIs.
---
 src/dict.cpp                          |  8 ++++++++
 src/object/function_doc_signature.cpp | 15 +++++++++++++--
 src/wrapper.cpp                       | 20 ++++++++++++++------
 3 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/src/dict.cpp b/src/dict.cpp
index 77d840d4..296bc21e 100644
--- a/src/dict.cpp
+++ b/src/dict.cpp
@@ -68,8 +68,16 @@ object dict_base::get(object_cref k) const
 {
     if (check_exact(this))
     {
+#ifdef Py_GIL_DISABLED
+        PyObject* result;
+        if (PyDict_GetItemRef(this->ptr(),k.ptr(),&result) < 0) {
+            throw_error_already_set();
+        }
+        return object(detail::new_reference(result ? result : Py_None));
+#else
         PyObject* result = PyDict_GetItem(this->ptr(),k.ptr());
         return object(detail::borrowed_reference(result ? result : Py_None));
+#endif
     }
     else
     {
diff --git a/src/object/function_doc_signature.cpp b/src/object/function_doc_signature.cpp
index 18d45869..76b620dc 100644
--- a/src/object/function_doc_signature.cpp
+++ b/src/object/function_doc_signature.cpp
@@ -135,7 +135,15 @@ namespace boost { namespace python { namespace objects {
             str name(get_qualname(py_type));
             if ( py_type->tp_flags & Py_TPFLAGS_HEAPTYPE ) {
                 // Qualify the type name if it is defined in a different module.
-                PyObject *type_module_name = PyDict_GetItemString(py_type->tp_dict, "__module__");
+                PyObject *type_module_name;
+#if PY_VERSION_HEX >= 0x030D0000
+                if (PyDict_GetItemStringRef(py_type->tp_dict, "__module__", &type_module_name) < 0) {
+                    throw_error_already_set();
+                }
+#else
+                type_module_name = PyDict_GetItemString(py_type->tp_dict, "__module__");
+                Py_XINCREF(type_module_name);
+#endif
                 if (
                     type_module_name
                     && PyObject_RichCompareBool(
@@ -144,8 +152,11 @@ namespace boost { namespace python { namespace objects {
                         Py_NE
                     ) != 0
                 ) {
-                    return str("%s.%s" % make_tuple(handle<>(borrowed(type_module_name)), name));
+                    str result = str("%s.%s" % make_tuple(handle<>(type_module_name), name));
+                    return result;
                 }
+                // Clean up the strong reference if we didn't use it
+                Py_XDECREF(type_module_name);
             }
             return name;
         } else {
diff --git a/src/wrapper.cpp b/src/wrapper.cpp
index 8b1b8847..2b053d83 100644
--- a/src/wrapper.cpp
+++ b/src/wrapper.cpp
@@ -21,20 +21,28 @@ namespace detail
                           this->m_self, const_cast<char*>(name))))
           )
           {
-              PyObject* borrowed_f = 0;
-            
+              PyObject* class_f = 0;
+
               if (
                   PyMethod_Check(m.get())
                   && PyMethod_GET_SELF(m.get()) == this->m_self
                   && class_object->tp_dict != 0
               )
               {
-                  borrowed_f = ::PyDict_GetItemString(
+#if PY_VERSION_HEX >= 0x030D0000
+                  if (::PyDict_GetItemStringRef(
+                      class_object->tp_dict, const_cast<char*>(name), &class_f) < 0) {
+                      throw_error_already_set();
+                  }
+#else
+                  class_f = ::PyDict_GetItemString(
                       class_object->tp_dict, const_cast<char*>(name));
-
-
+                  Py_XINCREF(class_f);
+#endif
               }
-              if (borrowed_f != PyMethod_GET_FUNCTION(m.get()))
+              bool is_override = (class_f != PyMethod_GET_FUNCTION(m.get()));
+              Py_XDECREF(class_f);
+              if (is_override)
                   return override(m);
           }
       }