Fix a bug in pytype's handling of classes with the same name.

PiperOrigin-RevId: 333598812

pytype/attribute.py

@@ -310,11 +310,13 @@ def _get_attribute_from_super_instance(
       valself = obj.super_obj.to_binding(node)
       # When multiple inheritance is present, the two classes' MROs may differ.
       # In this case, we want to use the MRO of starting_cls but skip all the
-      # classes up to and including current_cls.
+      # classes up to and including current_cls. We traverse the MRO backwards
+      # to correctly handle the case in which the starting and current classes
+      # are different classes with the same name.
       skip = set()
-      for parent in starting_cls.mro:
-        skip.add(parent)
+      for i, parent in enumerate(reversed(starting_cls.mro)):
         if parent.full_name == current_cls.full_name:
+          skip.update(starting_cls.mro[:len(starting_cls.mro)-i])
           break
     else:
       starting_cls = self.vm.convert.super_type

pytype/tests/test_super.py

@@ -266,5 +266,15 @@ def __init__(self):
     """)
     self.assertErrorRegexes(errors, {"e": r"super"})
 
+  def test_duplicate_class_names(self):
+    self.Check("""
+      class Foo(object):
+        def __new__(self, *args, **kwargs):
+          typ = type('Foo', (Foo,), {})
+          return super(Foo, typ).__new__(typ)
+        def __init__(self, x):
+          super(Foo, self).__init__()
+    """)
+
 
 test_base.main(globals(), __name__ == "__main__")