pythongh-117613: Argument Clinic: ensure that 'defining_class' params are positional-only (python#117781)

Author: neonene

Lib/test/test_clinic.py

@@ -2508,6 +2508,16 @@ def test_state_func_docstring_only_one_param_template(self):
         """
         self.expect_failure(block, err, lineno=7)
 
+    def test_kind_defining_class(self):
+        function = self.parse_function("""
+            module m
+            class m.C "PyObject *" ""
+            m.C.meth
+                cls: defining_class
+        """, signatures_in_block=3, function_index=2)
+        p = function.parameters['cls']
+        self.assertEqual(p.kind, inspect.Parameter.POSITIONAL_ONLY)
+
 
 class ClinicExternalTest(TestCase):
     maxDiff = None

Modules/_sqlite/clinic/connection.c.h

@@ -1102,6 +1102,7 @@ def bad_node(self, node: ast.AST) -> None:
                     fail("A 'defining_class' parameter cannot have a default value.")
                 if self.group:
                     fail("A 'defining_class' parameter cannot be in an optional group.")
+                kind = inspect.Parameter.POSITIONAL_ONLY
             else:
                 fail("A 'defining_class' parameter, if specified, must either "
                      "be the first thing in the parameter block, or come just "