Index: Include/unicodeobject.h
===================================================================
--- Include/unicodeobject.h	(révision 85081)
+++ Include/unicodeobject.h	(copie de travail)
@@ -99,8 +99,8 @@
 #endif
 
 /* If the compiler provides a wchar_t type we try to support it
-   through the interface functions PyUnicode_FromWideChar() and
-   PyUnicode_AsWideChar(). */
+   through the interface functions PyUnicode_FromWideChar(),
+   PyUnicode_AsWideChar() and PyUnicode_AsWideCharString(). */
 
 #ifdef HAVE_USABLE_WCHAR_T
 # ifndef HAVE_WCHAR_H
@@ -156,6 +156,7 @@
 # define PyUnicode_AsUnicode PyUnicodeUCS2_AsUnicode
 # define PyUnicode_AsUnicodeEscapeString PyUnicodeUCS2_AsUnicodeEscapeString
 # define PyUnicode_AsWideChar PyUnicodeUCS2_AsWideChar
+# define PyUnicode_AsWideCharString PyUnicodeUCS2_AsWideCharString
 # define PyUnicode_ClearFreeList PyUnicodeUCS2_ClearFreelist
 # define PyUnicode_Compare PyUnicodeUCS2_Compare
 # define PyUnicode_CompareWithASCII PyUnicodeUCS2_CompareASCII
@@ -239,6 +240,7 @@
 # define PyUnicode_AsUnicode PyUnicodeUCS4_AsUnicode
 # define PyUnicode_AsUnicodeEscapeString PyUnicodeUCS4_AsUnicodeEscapeString
 # define PyUnicode_AsWideChar PyUnicodeUCS4_AsWideChar
+# define PyUnicode_AsWideCharString PyUnicodeUCS4_AsWideCharString
 # define PyUnicode_ClearFreeList PyUnicodeUCS4_ClearFreelist
 # define PyUnicode_Compare PyUnicodeUCS4_Compare
 # define PyUnicode_CompareWithASCII PyUnicodeUCS4_CompareWithASCII
@@ -570,6 +572,18 @@
     Py_ssize_t size             /* size of buffer */
     );
 
+/* Convert the Unicode object to a wide character string. The output string
+   always ends with a nul character. If size is not NULL, write the number of
+   wide characters (including the final nul character) into *size.
+
+   Returns a buffer allocated by PyMem_Alloc() (use PyMem_Free() to free it) on
+   success. On error, returns NULL and *size is undefined. */
+
+PyAPI_FUNC(wchar_t*) PyUnicode_AsWideCharString(
+    PyUnicodeObject *unicode,   /* Unicode object */
+    Py_ssize_t *size            /* number of characters of the result */
+    );
+
 #endif
 
 /* --- Unicode ordinals --------------------------------------------------- */
Index: Objects/unicodeobject.c
===================================================================
--- Objects/unicodeobject.c	(révision 85081)
+++ Objects/unicodeobject.c	(copie de travail)
@@ -1153,10 +1153,27 @@
     return ret;
 }
 
-Py_ssize_t PyUnicode_AsWideChar(PyUnicodeObject *unicode,
-                                wchar_t *w,
-                                Py_ssize_t size)
+static void
+unicode_aswidechar(PyUnicodeObject *unicode,
+                   wchar_t *w,
+                   Py_ssize_t size)
 {
+#if Py_UNICODE_SIZE == SIZEOF_WCHAR_T
+    memcpy(w, unicode->str, size * sizeof(wchar_t));
+#else
+    register Py_UNICODE *u;
+    register Py_ssize_t i;
+    u = PyUnicode_AS_UNICODE(unicode);
+    for (i = size; i > 0; i--)
+        *w++ = *u++;
+#endif
+}
+
+Py_ssize_t
+PyUnicode_AsWideChar(PyUnicodeObject *unicode,
+                     wchar_t *w,
+                     Py_ssize_t size)
+{
     if (unicode == NULL) {
         PyErr_BadInternalCall();
         return -1;
@@ -1166,17 +1183,7 @@
     if (size > PyUnicode_GET_SIZE(unicode))
         size = PyUnicode_GET_SIZE(unicode) + 1;
 
-#if Py_UNICODE_SIZE == SIZEOF_WCHAR_T
-    memcpy(w, unicode->str, size * sizeof(wchar_t));
-#else
-    {
-        register Py_UNICODE *u;
-        register Py_ssize_t i;
-        u = PyUnicode_AS_UNICODE(unicode);
-        for (i = size; i > 0; i--)
-            *w++ = *u++;
-    }
-#endif
+    unicode_aswidechar(unicode, w, size);
 
     if (size > PyUnicode_GET_SIZE(unicode))
         return PyUnicode_GET_SIZE(unicode);
@@ -1184,6 +1191,29 @@
         return size;
 }
 
+wchar_t*
+PyUnicode_AsWideCharString(PyUnicodeObject *unicode,
+                           Py_ssize_t *size)
+{
+    wchar_t* buffer;
+    Py_ssize_t buflen, ret;
+
+    if (unicode == NULL) {
+        PyErr_BadInternalCall();
+        return NULL;
+    }
+
+    if ((PY_SSIZE_T_MAX / sizeof(wchar_t) - 1) > PyUnicode_GET_SIZE(unicode))
+        return PyErr_NoMemory();
+
+    buflen = PyUnicode_GET_SIZE(unicode) + 1; /* copy L'\0' */
+    buffer = PyMem_MALLOC(buflen * sizeof(wchar_t));
+    if (buffer == NULL)
+        return PyErr_NoMemory();
+    unicode_aswidechar(unicode, buffer, buflen);
+    return buflen;
+}
+
 #endif
 
 PyObject *PyUnicode_FromOrdinal(int ordinal)
Index: Doc/c-api/unicode.rst
===================================================================
--- Doc/c-api/unicode.rst	(révision 85081)
+++ Doc/c-api/unicode.rst	(copie de travail)
@@ -462,6 +462,16 @@
    required by the application.
 
 
+.. cfunction:: wchar_t* PyUnicode_AsWideCharString(PyUnicodeObject *unicode, Py_ssize_t *size)
+
+    Convert the Unicode object to a wide character string. The output string
+    always ends with a nul character. If *size* is not *NULL*, write the number
+    of wide characters (including the final nul character) into *\*size*.
+
+    Returns a buffer allocated by :cfunc:`PyMem_Alloc` (use :cfunc:`PyMem_Free`
+    to free it) on success. On error, returns *NULL* and *\*size* is undefined.
+
+
 .. _builtincodecs:
 
 Built-in Codecs
Index: Modules/_localemodule.c
===================================================================
--- Modules/_localemodule.c	(révision 85081)
+++ Modules/_localemodule.c	(copie de travail)
@@ -242,29 +242,16 @@
 {
     PyObject *os1, *os2, *result = NULL;
     wchar_t *ws1 = NULL, *ws2 = NULL;
-    Py_ssize_t len1, len2;
 
     if (!PyArg_ParseTuple(args, "UU:strcoll", &os1, &os2))
         return NULL;
     /* Convert the unicode strings to wchar[]. */
-    len1 = PyUnicode_GET_SIZE(os1) + 1;
-    ws1 = PyMem_MALLOC(len1 * sizeof(wchar_t));
-    if (!ws1) {
-        PyErr_NoMemory();
+    ws1 = PyUnicode_AsWideCharString((PyUnicodeObject*)os1, NULL);
+    if (ws1 == NULL)
         goto done;
-    }
-    if (PyUnicode_AsWideChar((PyUnicodeObject*)os1, ws1, len1) == -1)
+    ws2 = PyUnicode_AsWideCharString((PyUnicodeObject*)os2, NULL);
+    if (ws2 == NULL)
         goto done;
-    ws1[len1 - 1] = 0;
-    len2 = PyUnicode_GET_SIZE(os2) + 1;
-    ws2 = PyMem_MALLOC(len2 * sizeof(wchar_t));
-    if (!ws2) {
-        PyErr_NoMemory();
-        goto done;
-    }
-    if (PyUnicode_AsWideChar((PyUnicodeObject*)os2, ws2, len2) == -1)
-        goto done;
-    ws2[len2 - 1] = 0;
     /* Collate the strings. */
     result = PyLong_FromLong(wcscoll(ws1, ws2));
   done: