Fix crash on unimported Any in TypedDict (#16510)

Fixes #16498

Fix is trivial: no operations can be done with `Required` types before
unwrapping (because they are not real types).

---------

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

mypy/semanal_typeddict.py

@@ -394,6 +394,17 @@ def check_typeddict(
             types = [  # unwrap Required[T] to just T
                 t.item if isinstance(t, RequiredType) else t for t in types
             ]
+
+            # Perform various validations after unwrapping.
+            for t in types:
+                check_for_explicit_any(
+                    t, self.options, self.api.is_typeshed_stub_file, self.msg, context=call
+                )
+            if self.options.disallow_any_unimported:
+                for t in types:
+                    if has_any_from_unimported_type(t):
+                        self.msg.unimported_type_becomes_any("Type of a TypedDict key", t, call)
+
             existing_info = None
             if isinstance(node.analyzed, TypedDictExpr):
                 existing_info = node.analyzed.info
@@ -451,15 +462,6 @@ def parse_typeddict_args(
             # One of the types is not ready, defer.
             return None
         items, types, ok = res
-        for t in types:
-            check_for_explicit_any(
-                t, self.options, self.api.is_typeshed_stub_file, self.msg, context=call
-            )
-
-        if self.options.disallow_any_unimported:
-            for t in types:
-                if has_any_from_unimported_type(t):
-                    self.msg.unimported_type_becomes_any("Type of a TypedDict key", t, dictexpr)
         assert total is not None
         return args[0].value, items, types, total, tvar_defs, ok
 

test-data/unit/check-typeddict.test

@@ -3396,3 +3396,15 @@ reveal_type(b["a"])  # N: Revealed type is "Union[builtins.str, None]"
 reveal_type(b["g"])  # N: Revealed type is "Union[builtins.int, None]"
 [builtins fixtures/dict.pyi]
 [typing fixtures/typing-typeddict.pyi]
+
+[case testNoCrashOnUnImportedAnyNotRequired]
+# flags: --disallow-any-unimported
+from typing import NotRequired, Required, TypedDict
+from thismoduledoesntexist import T  # type: ignore[import]
+
+B = TypedDict("B", {  # E: Type of a TypedDict key becomes "Any" due to an unfollowed import
+    "T1": NotRequired[T],
+    "T2": Required[T],
+})
+[builtins fixtures/dict.pyi]
+[typing fixtures/typing-typeddict.pyi]