.

Author: hauntsaninja

mypy/checker.py

@@ -8685,7 +8685,7 @@ def flatten_types_if_tuple(t: Type) -> list[Type]:
     """Flatten a nested sequence of tuples into one list of nodes."""
     t = get_proper_type(t)
     if isinstance(t, UnionType):
-        return [b for a in t.items for b in flatten_types(a)]
+        return [b for a in t.items for b in flatten_types_if_tuple(a)]
     if isinstance(t, TupleType):
         return [b for a in t.items for b in flatten_types_if_tuple(a)]
     elif is_named_instance(t, "builtins.tuple"):