Index: Python/fileutils.c
===================================================================
--- Python/fileutils.c	(révision 85310)
+++ Python/fileutils.c	(copie de travail)
@@ -336,7 +336,7 @@
 #ifdef HAVE_REALPATH
 
 /* Return the canonicalized absolute pathname. Encode path to the locale
-   encoding, decode the result from the locale encoding. */
+   encoding, decode the result from the filesystem encoding. */
 
 wchar_t*
 _Py_wrealpath(const wchar_t *path,
@@ -345,21 +345,28 @@
     char *cpath;
     char cresolved_path[PATH_MAX];
     char *res;
-    size_t r;
+    Py_ssize_t r;
+    PyObject *unicode;
+
     cpath = _Py_wchar2char(path);
-    if (cpath == NULL) {
-        errno = EINVAL;
+    if (cpath == NULL)
         return NULL;
-    }
+
     res = realpath(cpath, cresolved_path);
     PyMem_Free(cpath);
     if (res == NULL)
         return NULL;
-    r = mbstowcs(resolved_path, cresolved_path, resolved_path_size);
-    if (r == (size_t)-1 || r >= PATH_MAX) {
-        errno = EINVAL;
+
+    unicode = PyUnicode_DecodeFSDefault(cresolved_path);
+    if (unicode == NULL)
         return NULL;
-    }
+
+    r = PyUnicode_AsWideChar((PyUnicodeObject*)unicode,
+        resolved_path, resolved_path_size);
+    Py_DECREF(unicode);
+    if (r == -1 || r == resolved_path_size)
+        return NULL;
+
     return resolved_path;
 }
 #endif