pythongh-106359: Fix corner case bugs in Argument Clinic converter parser

DSLParser.parse_converter() could return unusable kwdicts in some rare cases

Author: erlend-aasland

Lib/test/test_clinic.py

@@ -797,21 +797,18 @@ def test_other_bizarre_things_in_annotations_fail(self):
 Error on line 0:
 Annotations must be either a name, a function call, or a string.
 """
-
-        s = self.parse_function_should_fail(
-            'module os\nos.access\n   path: {"some": "dictionary"}'
-        )
-        self.assertEqual(s, expected_failure_message)
-
-        s = self.parse_function_should_fail(
-            'module os\nos.access\n   path: ["list", "of", "strings"]'
+        dataset = (
+            'module os\nos.access\n   path: {"some": "dictionary"}',
+            'module os\nos.access\n   path: ["list", "of", "strings"]',
+            'module os\nos.access\n   path: (x for x in range(42))',
+            'module fo\nfo.barbaz\n   o: bool(**{None: "bang!"})',
+            'module fo\nfo.barbaz -> bool(**{None: "bang!"})',
         )
-        self.assertEqual(s, expected_failure_message)
 
-        s = self.parse_function_should_fail(
-            'module os\nos.access\n   path: (x for x in range(42))'
-        )
-        self.assertEqual(s, expected_failure_message)
+        for fn in dataset:
+            with self.subTest(fn=fn):
+                actual = self.parse_function_should_fail(fn)
+                self.assertEqual(actual, expected_failure_message)
 
     def test_unused_param(self):
         block = self.parse("""

Tools/clinic/clinic.py

@@ -5033,26 +5033,27 @@ def bad_node(self, node):
         key = f"{parameter_name}_as_{c_name}" if c_name else parameter_name
         self.function.parameters[key] = p
 
-    KwargDict = dict[str | None, Any]
+    KwargDict = dict[str, Any]
 
     @staticmethod
     def parse_converter(annotation: ast.expr | None) -> tuple[str, bool, KwargDict]:
+        msg = "Annotations must be either a name, a function call, or a string."
         match annotation:
             case ast.Constant(value=str() as value):
                 return value, True, {}
             case ast.Name(name):
                 return name, False, {}
             case ast.Call(func=ast.Name(name)):
                 symbols = globals()
-                kwargs = {
-                    node.arg: eval_ast_expr(node.value, symbols)
-                    for node in annotation.keywords
-                }
+                kwargs: dict[str, Any] = {}
+                for node in annotation.keywords:
+                    if not isinstance(node.arg, str):
+                        fail(msg)
+                    kwargs[node.arg] = eval_ast_expr(node.value, symbols)
+                    print(kwargs)
                 return name, False, kwargs
             case _:
-                fail(
-                    "Annotations must be either a name, a function call, or a string."
-                )
+                fail(msg)
 
     def parse_special_symbol(self, symbol):
         if symbol == '*':