From 42337a0ca0923ce9cf7492c6d847a945a69ad7a6 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Sun, 14 Jul 2024 13:02:43 +0100
Subject: [PATCH] [mypyc] Don't use _PyUnicode_FastCopyCharacters on 3.13
 (#17524)

Work on mypyc/mypyc#1056.
---
 mypyc/lib-rt/str_ops.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mypyc/lib-rt/str_ops.c b/mypyc/lib-rt/str_ops.c
index 90b19001f8f0..4ba181bcce85 100644
--- a/mypyc/lib-rt/str_ops.c
+++ b/mypyc/lib-rt/str_ops.c
@@ -117,7 +117,11 @@ PyObject *CPyStr_Build(Py_ssize_t len, ...) {
             PyObject *item = va_arg(args, PyObject *);
             Py_ssize_t itemlen = PyUnicode_GET_LENGTH(item);
             if (itemlen != 0) {
+#if CPY_3_13_FEATURES
+                PyUnicode_CopyCharacters(res, res_offset, item, 0, itemlen);
+#else
                 _PyUnicode_FastCopyCharacters(res, res_offset, item, 0, itemlen);
+#endif
                 res_offset += itemlen;
             }
         }