added _Py_normpathAndSize

Include/internal/pycore_fileutils.h

@@ -253,6 +253,7 @@ extern int _Py_add_relfile(wchar_t *dirname,
                            size_t bufsize);
 extern size_t _Py_find_basename(const wchar_t *filename);
 PyAPI_FUNC(wchar_t *) _Py_normpath(wchar_t *path, Py_ssize_t size);
+PyAPI_FUNC(wchar_t *) _Py_normpathAndSize(wchar_t *path, Py_ssize_t size, Py_ssize_t *length);
 
 // The Windows Games API family does not provide these functions
 // so provide our own implementations. Remove them in case they get added

Modules/posixmodule.c

@@ -5275,7 +5275,11 @@ os__path_normpath_impl(PyObject *module, PyObject *path)
     if (!buffer) {
         return NULL;
     }
-    PyObject *result = PyUnicode_FromWideChar(_Py_normpath(buffer, len), -1);
+    Py_ssize_t end_len;
+    wchar_t *norm_path = _Py_normpathAndSize(buffer, len, &end_len);
+    printf("len: %d\n", len);
+    printf("end_len: %d\n", end_len);
+    PyObject *result = PyUnicode_FromWideChar(norm_path, -1);
     PyMem_Free(buffer);
     return result;
 }

Python/fileutils.c

@@ -2379,7 +2379,7 @@ _Py_find_basename(const wchar_t *filename)
    the path, if known. If -1, the first null character will be assumed
    to be the end of the path. */
 wchar_t *
-_Py_normpath(wchar_t *path, Py_ssize_t size)
+_Py_normpathAndSize(wchar_t *path, Py_ssize_t size, Py_ssize_t *length)
 {
     assert(path != NULL);
     if (!path[0] || size == 0) {
@@ -2447,8 +2447,11 @@ _Py_normpath(wchar_t *path, Py_ssize_t size)
     }
 #endif /* MS_WINDOWS */
 
+    *length = size;
+
     /* if pEnd is specified, check that. Else, check for null terminator */
     for (; !IS_END(p1); ++p1) {
+        *length++;
         wchar_t c = *p1;
 #ifdef ALTSEP
         if (c == ALTSEP) {
@@ -2502,6 +2505,13 @@ _Py_normpath(wchar_t *path, Py_ssize_t size)
     return path;
 }
 
+wchar_t *
+_Py_normpath(wchar_t *path, Py_ssize_t size)
+{
+    Py_ssize_t length;
+    return _Py_normpathAndSize(path, size, &length);
+}
+
 
 /* Get the current directory. buflen is the buffer size in wide characters
    including the null character. Decode the path from the locale encoding.