[3.11] gh-46376: Return existing pointer when possible in ctypes (GH-107131) by ambv · Pull Request #107488 · python/cpython

python

@@ -5158,6 +5158,8 @@ static PyObject * Pointer_get_contents(CDataObject *self, void *closure) { StgDictObject *stgdict; PyObject *keep, *ptr_probe; CDataObject *ptr2ptr;
if (*(void **)self->b_ptr == NULL) { PyErr_SetString(PyExc_ValueError, @@ -5167,6 +5169,33 @@ Pointer_get_contents(CDataObject *self, void *closure)
stgdict = PyObject_stgdict((PyObject *)self); assert(stgdict); /* Cannot be NULL for pointer instances */
keep = GetKeepedObjects(self); if (keep != NULL) { // check if it's a pointer to a pointer: // pointers will have '0' key in the _objects ptr_probe = PyDict_GetItemString(keep, "0");
if (ptr_probe != NULL) { ptr2ptr = (CDataObject*) PyDict_GetItemString(keep, "1"); if (ptr2ptr == NULL) { PyErr_SetString(PyExc_ValueError, "Unexpected NULL pointer in _objects"); return NULL; } // don't construct a new object, // return existing one instead to preserve refcount assert( *(void**) self->b_ptr == ptr2ptr->b_ptr || *(void**) self->b_value.c == ptr2ptr->b_ptr || *(void**) self->b_ptr == ptr2ptr->b_value.c || *(void**) self->b_value.c == ptr2ptr->b_value.c ); // double-check that we are returning the same thing Py_INCREF(ptr2ptr); return (PyObject *) ptr2ptr; } }
return PyCData_FromBaseObj(stgdict->proto, (PyObject *)self, 0, *(void **)self->b_ptr);