Add hint, satisfy self type-checking

Author: brianschubert

mypy/typeanal.py

@@ -819,15 +819,14 @@ def try_analyze_special_unbound_type(self, t: UnboundType, fullname: str) -> Typ
                 )
                 return AnyType(TypeOfAny.from_error)
             item = t.args[0]
-            if not isinstance(get_proper_type(item), TypedDictType):
+            if not isinstance(item, TypedDictType):  # type: ignore[misc]
                 self.fail(
                     "Argument to TypedDict[] must be a literal dictionary mapping item names to types",
                     t,
                     code=codes.VALID_TYPE,
                 )
                 return AnyType(TypeOfAny.from_error)
-            else:
-                item.is_pep764 = True
+            item.is_pep764 = True
             return self.anal_type(item, allow_typed_dict_special_forms=True)
         return None
 

mypy/types.py

@@ -2585,6 +2585,7 @@ class TypedDictType(ProperType):
 
     extra_items_from: list[ProperType]  # only used during semantic analysis
     to_be_mutated: bool  # only used in a plugin for `.update`, `|=`, etc
+    is_pep764: bool
 
     def __init__(
         self,