bpo-41798: Allocate the _curses._C_API on the heap memory (GH-24186)

Modules/_cursesmodule.c

@@ -4725,22 +4725,23 @@ static struct PyModuleDef _cursesmodule = {
     NULL
 };
 
+static void
+curses_destructor(PyObject *op)
+{
+    void *ptr = PyCapsule_GetPointer(op, PyCurses_CAPSULE_NAME);
+    Py_DECREF(*(void **)ptr);
+    PyMem_Free(ptr);
+}
+
 PyMODINIT_FUNC
 PyInit__curses(void)
 {
     PyObject *m, *d, *v, *c_api_object;
-    static void *PyCurses_API[PyCurses_API_pointers];
 
     /* Initialize object type */
     if (PyType_Ready(&PyCursesWindow_Type) < 0)
         return NULL;
 
-    /* Initialize the C API pointer array */
-    PyCurses_API[0] = (void *)&PyCursesWindow_Type;
-    PyCurses_API[1] = (void *)func_PyCursesSetupTermCalled;
-    PyCurses_API[2] = (void *)func_PyCursesInitialised;
-    PyCurses_API[3] = (void *)func_PyCursesInitialisedColor;
-
     /* Create the module and add the functions */
     m = PyModule_Create(&_cursesmodule);
     if (m == NULL)
@@ -4752,9 +4753,29 @@ PyInit__curses(void)
         return NULL;
     ModDict = d; /* For PyCurses_InitScr to use later */
 
+    void **PyCurses_API = PyMem_Calloc(PyCurses_API_pointers, sizeof(void *));
+    if (PyCurses_API == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+    /* Initialize the C API pointer array */
+    PyCurses_API[0] = (void *)Py_NewRef(&PyCursesWindow_Type);
+    PyCurses_API[1] = (void *)func_PyCursesSetupTermCalled;
+    PyCurses_API[2] = (void *)func_PyCursesInitialised;
+    PyCurses_API[3] = (void *)func_PyCursesInitialisedColor;
+
     /* Add a capsule for the C API */
-    c_api_object = PyCapsule_New(PyCurses_API, PyCurses_CAPSULE_NAME, NULL);
-    PyDict_SetItemString(d, "_C_API", c_api_object);
+    c_api_object = PyCapsule_New(PyCurses_API, PyCurses_CAPSULE_NAME,
+                                 curses_destructor);
+    if (c_api_object == NULL) {
+        Py_DECREF(PyCurses_API[0]);
+        PyMem_Free(PyCurses_API);
+        return NULL;
+    }
+    if (PyDict_SetItemString(d, "_C_API", c_api_object) < 0) {
+        Py_DECREF(c_api_object);
+        return NULL;
+    }
     Py_DECREF(c_api_object);
 
     /* For exception curses.error */