Replace Py_FileSystemDefaultEncoding

Author: Starbuck5

src_c/rwobject.c

@@ -243,8 +243,39 @@ pg_EncodeString(PyObject *obj, const char *encoding, const char *errors,
 static PyObject *
 pg_EncodeFilePath(PyObject *obj, PyObject *eclass)
 {
-    PyObject *result = pg_EncodeString(obj, Py_FileSystemDefaultEncoding,
-                                       UNICODE_DEF_FS_ERROR, eclass);
+    /* All of this code is a replacement for Py_FileSystemDefaultEncoding,
+     * which is deprecated in Python 3.12
+     *
+     * But I'm not sure of the use of this function, so maybe it should be
+     * deprecated. */
+
+    PyObject *sys_module = PyImport_ImportModule("sys");
+    if (sys_module == NULL) {
+        return NULL;
+    }
+    PyObject *system_encoding_obj =
+        PyObject_CallMethod(sys_module, "getfilesystemencoding", NULL);
+    if (system_encoding_obj == NULL) {
+        Py_DECREF(sys_module);
+        return NULL;
+    }
+    Py_DECREF(sys_module);
+    const char *encoding = PyUnicode_AsUTF8(system_encoding_obj);
+    if (encoding == NULL) {
+        Py_DECREF(system_encoding_obj);
+        return NULL;
+    }
+
+    /* End code replacement section */
+
+    if (obj == NULL) {
+        PyErr_SetString(PyExc_SyntaxError, "Forwarded exception");
+    }
+
+    PyObject *result =
+        pg_EncodeString(obj, encoding, UNICODE_DEF_FS_ERROR, eclass);
+    Py_DECREF(system_encoding_obj);
+
     if (result == NULL || result == Py_None) {
         return result;
     }
@@ -817,9 +848,6 @@ pg_encode_file_path(PyObject *self, PyObject *args, PyObject *keywds)
         return NULL;
     }
 
-    if (obj == NULL) {
-        PyErr_SetString(PyExc_SyntaxError, "Forwarded exception");
-    }
     return pg_EncodeFilePath(obj, eclass);
 }