diff -r 48228fb874c1 Python/fileutils.c
--- a/Python/fileutils.c	Mon Nov 05 09:34:46 2012 +0200
+++ b/Python/fileutils.c	Mon Nov 05 22:59:50 2012 +0100
@@ -7,6 +7,10 @@
 #include <langinfo.h>
 #endif
 
+#ifdef __APPLE__
+extern wchar_t* _Py_DecodeUTF8_surrogateescape(const char *s, Py_ssize_t size);
+#endif
+
 PyObject *
 _Py_device_encoding(int fd)
 {
@@ -244,6 +248,71 @@ char*
     return result;
 }
 
+/* Encode a filename to the filesystem encoding with the
+   surrogateescape error handler: see _Py_wchar2char().
+
+   Return a pointer to a newly allocated byte string (use PyMem_Free() to free
+   the memory), or NULL on encoding or memory allocation error. */
+static char*
+_Py_encode_filename(const wchar_t *path)
+{
+#ifdef __APPLE__
+    Py_ssize_t len;
+    PyObject *unicode, *bytes = NULL;
+    char *cpath;
+
+    unicode = PyUnicode_FromWideChar(path, wcslen(path));
+    if (unicode == NULL) {
+        Py_DECREF(unicode);
+        return NULL;
+    }
+
+    bytes = PyUnicode_EncodeFSDefault(unicode);
+    Py_DECREF(unicode);
+    if (bytes == NULL) {
+        PyErr_Clear();
+        return NULL;
+    }
+
+    len = PyBytes_GET_SIZE(bytes);
+    cpath = PyMem_Malloc(len+1);
+    if (cpath == NULL) {
+        Py_DECREF(bytes);
+        return NULL;
+    }
+    memcpy(cpath, PyBytes_AsString(bytes), len + 1);
+    Py_DECREF(bytes);
+    return cpath;
+#else
+    return _Py_wchar2char(path, NULL);
+#endif
+}
+
+/* Decode a filename from the filesystem encoding with the surrogateescape
+   error handler: see _Py_char2wchar().
+
+   Return a pointer to a newly allocated wide character string (use
+   PyMem_Free() to free the memory) and write the number of written wide
+   characters excluding the null character into *size if size is not NULL, or
+   NULL on error (decoding or memory allocation error). If size is not NULL,
+   *size is set to (size_t)-1 on memory error and (size_t)-2 on decoding
+   error. */
+static wchar_t*
+_Py_decode_filename(const char *path, size_t *len)
+{
+
+#ifdef __APPLE__
+    wchar_t *wpath;
+    wpath = _Py_DecodeUTF8_surrogateescape(path, strlen(path));
+    if (wpath == NULL)
+        return NULL;
+    *len = wcslen(wpath);
+    return wpath;
+#else
+    return _Py_char2wchar(path, len);
+#endif
+}
+
 /* In principle, this should use HAVE__WSTAT, and _wstat
    should be detected by autoconf. However, no current
    POSIX system provides that function, so testing for
@@ -260,7 +329,7 @@ int
 {
     int err;
     char *fname;
-    fname = _Py_wchar2char(path, NULL);
+    fname = _Py_encode_filename(path);
     if (fname == NULL) {
         errno = EINVAL;
         return -1;
@@ -319,7 +388,7 @@ FILE *
         errno = EINVAL;
         return NULL;
     }
-    cpath = _Py_wchar2char(path, NULL);
+    cpath = _Py_encode_filename(path);
     if (cpath == NULL)
         return NULL;
     f = fopen(cpath, cmode);
@@ -384,7 +453,7 @@ int
     int res;
     size_t r1;
 
-    cpath = _Py_wchar2char(path, NULL);
+    cpath = _Py_encode_filename(path);
     if (cpath == NULL) {
         errno = EINVAL;
         return -1;
@@ -398,7 +467,7 @@ int
         return -1;
     }
     cbuf[res] = '\0'; /* buf will be null terminated */
-    wbuf = _Py_char2wchar(cbuf, &r1);
+    wbuf = _Py_decode_filename(cbuf, &r1);
     if (wbuf == NULL) {
         errno = EINVAL;
         return -1;
@@ -429,7 +498,7 @@ wchar_t*
     wchar_t *wresolved_path;
     char *res;
     size_t r;
-    cpath = _Py_wchar2char(path, NULL);
+    cpath = _Py_encode_filename(path);
     if (cpath == NULL) {
         errno = EINVAL;
         return NULL;
@@ -439,7 +508,7 @@ wchar_t*
     if (res == NULL)
         return NULL;
 
-    wresolved_path = _Py_char2wchar(cresolved_path, &r);
+    wresolved_path = _Py_decode_filename(cresolved_path, &r);
     if (wresolved_path == NULL) {
         errno = EINVAL;
         return NULL;
@@ -471,7 +540,7 @@ wchar_t*
 
     if (getcwd(fname, PATH_MAX) == NULL)
         return NULL;
-    wname = _Py_char2wchar(fname, &len);
+    wname = _Py_decode_filename(fname, &len);
     if (wname == NULL)
         return NULL;
     if (size <= len) {