bpo-29852: Argument Clinic Py_ssize_t converter now supports None (#716)

if pass `accept={int, NoneType}`.

1 files changed, 10 insertions, 2 deletions

diff --git a/Tools/clinic/clinic.py b/Tools/clinic/clinic.py
index 53108b1..1d570f1 100755
--- a/Tools/clinic/clinic.py
+++ b/Tools/clinic/clinic.py
@@ -2650,12 +2650,20 @@ class unsigned_long_long_converter(CConverter):
         if not bitwise:
             fail("Unsigned long long must be bitwise (for now).")
 
+
 class Py_ssize_t_converter(CConverter):
     type = 'Py_ssize_t'
-    default_type = int
-    format_unit = 'n'
     c_ignored_default = "0"
 
+    def converter_init(self, *, accept={int}):
+        if accept == {int}:
+            self.format_unit = 'n'
+            self.default_type = int
+        elif accept == {int, NoneType}:
+            self.converter = '_Py_convert_optional_to_ssize_t'
+        else:
+            fail("Py_ssize_t_converter: illegal 'accept' argument " + repr(accept))
+
 
 class slice_index_converter(CConverter):
     type = 'Py_ssize_t'