Do not forget that a TypedDict was wrapped in Unpack after a name-defined error occurred. (#17226)

Do not set the `unpacked_kwargs` attribute of `CallableType` to False
when visiting a callable of which the `Unpack` wrapper of a `TypedDict`
has already been removed.

Fixes #17225

Author: tyralla

mypy/typeanal.py

@@ -1030,7 +1030,7 @@ def visit_parameters(self, t: Parameters) -> Type:
     def visit_callable_type(self, t: CallableType, nested: bool = True) -> Type:
         # Every Callable can bind its own type variables, if they're not in the outer scope
         with self.tvar_scope_frame():
-            unpacked_kwargs = False
+            unpacked_kwargs = t.unpack_kwargs
             if self.defining_alias:
                 variables = t.variables
             else:

test-data/unit/check-typeddict.test

@@ -3487,3 +3487,41 @@ class A(Generic[T]):
         return self.a(x=1)
 [typing fixtures/typing-full.pyi]
 [builtins fixtures/tuple.pyi]
+
+[case testNameUndefinedErrorDoesNotLoseUnpackedKWArgsInformation]
+from typing import overload
+from typing_extensions import TypedDict, Unpack
+
+class TD(TypedDict, total=False):
+    x: int
+    y: str
+
+@overload
+def f(self, *, x: int) -> None: ...
+@overload
+def f(self, *, y: str) -> None: ...
+def f(self, **kwargs: Unpack[TD]) -> None:
+    z  # E: Name "z" is not defined
+
+@overload
+def g(self, *, x: float) -> None: ...
+@overload
+def g(self, *, y: str) -> None: ...
+def g(self, **kwargs: Unpack[TD]) -> None:  # E: Overloaded function implementation does not accept all possible arguments of signature 1
+    z  # E: Name "z" is not defined
+
+class A:
+    def f(self, *, x: int) -> None: ...
+    def g(self, *, x: float) -> None: ...
+class B(A):
+    def f(self, **kwargs: Unpack[TD]) -> None:
+        z  # E: Name "z" is not defined
+    def g(self, **kwargs: Unpack[TD]) -> None:  # E: Signature of "g" incompatible with supertype "A" \
+                                                # N:      Superclass: \
+                                                # N:          def g(self, *, x: float) -> None \
+                                                # N:      Subclass: \
+                                                # N:          def g(*, x: int = ..., y: str = ...) -> None
+        z  # E: Name "z" is not defined
+reveal_type(B.f)  # N: Revealed type is "def (self: __main__.B, **kwargs: Unpack[TypedDict('__main__.TD', {'x'?: builtins.int, 'y'?: builtins.str})])"
+B().f(x=1.0)  # E: Argument "x" to "f" of "B" has incompatible type "float"; expected "int"
+[builtins fixtures/primitives.pyi]