From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Sun, 18 Feb 2018 18:40:07 +0000 (-0800)
Subject: bpo-32869: Fix incorrect dst buffer size for MultiByteToWideChar (GH-5739)
X-Git-Tag: v3.7.0b2~60
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ca82e3c0ec4d0d5ce4e1ffec98cc341cb5913446;p=python

bpo-32869: Fix incorrect dst buffer size for MultiByteToWideChar (GH-5739)


This function expects the destination buffer size to be given
in wide characters, not bytes.
(cherry picked from commit b3b4a9d3001f1fc7df8efcccdce081de54fa5eab)

Co-authored-by: Alexey Izbyshev <izbyshev@users.noreply.github.com>
---

diff --git a/Python/fileutils.c b/Python/fileutils.c
index 3cf8b7a8b6..32aeea4f10 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -1289,7 +1289,8 @@ _Py_fopen_obj(PyObject *path, const char *mode)
     if (wpath == NULL)
         return NULL;
 
-    usize = MultiByteToWideChar(CP_ACP, 0, mode, -1, wmode, sizeof(wmode));
+    usize = MultiByteToWideChar(CP_ACP, 0, mode, -1,
+                                wmode, Py_ARRAY_LENGTH(wmode));
     if (usize == 0) {
         PyErr_SetFromWindowsErr(0);
         return NULL;