Issue #8711: Document PyUnicode_DecodeFSDefault*() functions

 * Add paragraph titles to c-api/unicode.rst.
 * Fix PyUnicode_DecodeFSDefault*() comment: it now uses the "surrogateescape"
   error handler (and not "replace")
 * Remove "The function is intended to be used for paths and file names only
   during bootstrapping process where the codecs are not set up." from
   PyUnicode_FSConverter() comment: it is used after the bootstrapping and for
   other purposes than file names

1 files changed, 12 insertions, 8 deletions

diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index ff183f2..383187b 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -1240,25 +1240,29 @@ PyAPI_FUNC(int) PyUnicode_EncodeDecimal(
 /* --- File system encoding ---------------------------------------------- */
 
 /* ParseTuple converter which converts a Unicode object into the file
-   system encoding as a bytes object, using the PEP 383 error handler; bytes
-   objects are output as-is. */
+   system encoding as a bytes object, using the "surrogateescape" error
+   handler; bytes objects are output as-is. */
 
 PyAPI_FUNC(int) PyUnicode_FSConverter(PyObject*, void*);
 
-/* Decode a null-terminated string using Py_FileSystemDefaultEncoding.
+/* Decode a null-terminated string using Py_FileSystemDefaultEncoding
+   and the "surrogateescape" error handler.
 
-   If the encoding is supported by one of the built-in codecs (i.e., UTF-8,
-   UTF-16, UTF-32, Latin-1 or MBCS), otherwise fallback to UTF-8 and replace
-   invalid characters with '?'.
+   If Py_FileSystemDefaultEncoding is not set, fall back to UTF-8.
 
-   The function is intended to be used for paths and file names only
-   during bootstrapping process where the codecs are not set up.
+   Use PyUnicode_DecodeFSDefaultAndSize() if you have the string length.
 */
 
 PyAPI_FUNC(PyObject*) PyUnicode_DecodeFSDefault(
     const char *s               /* encoded string */
     );
 
+/* Decode a string using Py_FileSystemDefaultEncoding
+   and the "surrogateescape" error handler.
+
+   If Py_FileSystemDefaultEncoding is not set, fall back to UTF-8.
+*/
+
 PyAPI_FUNC(PyObject*) PyUnicode_DecodeFSDefaultAndSize(
     const char *s,               /* encoded string */
     Py_ssize_t size              /* size */