Fix crash caused by attr.s being passed a decorated class.

PiperOrigin-RevId: 309459874

pytype/overlays/classgen.py

@@ -140,6 +140,10 @@ def get_class_locals(self, cls, allow_methods, ordering):
     # TODO(rechen): Once we drop Python 2 support, either use a normal dict or
     # replace key deletion with OrderedDict.move_to_end().
     out = collections.OrderedDict()
+    if cls.name not in self.vm.local_ops:
+      # See TestAttribPy3.test_cannot_decorate in tests/py3/test_attr.py. The
+      # class will not be in local_ops if a previous decorator hides it.
+      return out
     for op in self.vm.local_ops[cls.name]:
       if is_dunder(op.name):
         continue

pytype/tests/CMakeLists.txt

@@ -523,6 +523,7 @@ py_test(
     test_attr.py
   DEPS
     .test_base
+    pytype.utils
 )
 
 py_test(

pytype/tests/py3/test_attr.py

@@ -1,5 +1,6 @@
 """Tests for attrs library in attr_overlay.py."""
 
+from pytype import file_utils
 from pytype.tests import test_base
 
 
@@ -104,6 +105,28 @@ class Foo(object):
         def __init__(self, x: int = ..., y: str = ...) -> None: ...
     """)
 
+  def test_cannot_decorate(self):
+    # Tests the attr.s decorator being passed an object it can't process.
+    with file_utils.Tempdir() as d:
+      d.create_file("foo.pyi", """
+        from typing import Type
+        class Foo: ...
+        def decorate(cls: Type[Foo]) -> Type[Foo]: ...
+      """)
+      ty = self.Infer("""
+        import attr
+        import foo
+        @attr.s
+        @foo.decorate
+        class Bar(foo.Foo): ...
+      """, pythonpath=[d.path])
+    self.assertTypesMatchPytd(ty, """
+      from typing import Type
+      attr: module
+      foo: module
+      Bar: Type[foo.Foo]
+    """)
+
 
 class TestAttrs(test_base.TargetPython3FeatureTest):
   """Tests for attr.s."""