hide the __class__ closure from the class body (#12370)

2 files changed, 28 insertions, 3 deletions

diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index 155403e..e791983 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -390,12 +390,13 @@ def _call_with_frames_removed(f, *args, **kwds):
 #                        keyword-only defaults)
 #     Python 3.4a1  3260 (add LOAD_CLASSDEREF; allow locals of class to override
 #                        free vars)
+#     Python 3.4a1  3270 (various tweaks to the __class_ closure)
 #
 # MAGIC must change whenever the bytecode emitted by the compiler may no
 # longer be understood by older implementations of the eval loop (usually
 # due to the addition of new opcodes).
 
-_MAGIC_BYTES = (3260).to_bytes(2, 'little') + b'\r\n'
+_MAGIC_BYTES = (3270).to_bytes(2, 'little') + b'\r\n'
 _RAW_MAGIC_NUMBER = int.from_bytes(_MAGIC_BYTES, 'little')
 
 _PYCACHE = '__pycache__'
diff --git a/Lib/test/test_super.py b/Lib/test/test_super.py
index 1e272ee..d0ce40a 100644
--- a/Lib/test/test_super.py
+++ b/Lib/test/test_super.py
@@ -81,8 +81,7 @@ class TestSuper(unittest.TestCase):
 
         self.assertEqual(E().f(), 'AE')
 
-    @unittest.expectedFailure
-    def test___class___set(self):
+    def test_various___class___pathologies(self):
         # See issue #12370
         class X(A):
             def f(self):
@@ -91,6 +90,31 @@ class TestSuper(unittest.TestCase):
         x = X()
         self.assertEqual(x.f(), 'A')
         self.assertEqual(x.__class__, 413)
+        class X:
+            x = __class__
+            def f():
+                __class__
+        self.assertIs(X.x, type(self))
+        with self.assertRaises(NameError) as e:
+            exec("""class X:
+                __class__
+                def f():
+                    __class__""", globals(), {})
+        self.assertIs(type(e.exception), NameError) # Not UnboundLocalError
+        class X:
+            global __class__
+            __class__ = 42
+            def f():
+                __class__
+        self.assertEqual(globals()["__class__"], 42)
+        del globals()["__class__"]
+        self.assertNotIn("__class__", X.__dict__)
+        class X:
+            nonlocal __class__
+            __class__ = 42
+            def f():
+                __class__
+        self.assertEqual(__class__, 42)
 
     def test___class___instancemethod(self):
         # See issue #14857