Add testcase for ticket #593

tests/bugs.txt

@@ -18,6 +18,7 @@ ipow_crash_T562
 pure_mode_cmethod_inheritance_T583
 genexpr_iterable_lookup_T600
 for_from_pyvar_loop_T601
+decorators_T593
 
 # CPython regression tests that don't current work:
 pyregr.test_threadsignals

tests/run/decorators_T593.pyx

+"""
+>>> am_i_buggy
+False
+>>> Foo
+False
+"""
+def testme(func):
+    try:
+        am_i_buggy
+        return True
+    except NameError:
+        return False
+@testme
+def am_i_buggy():
+    pass
+
+def testclass(klass):
+    try:
+        Foo
+        return True
+    except NameError:
+        return False
+@testclass
+class Foo:
+    pass
+
+class ODict(dict):
+   def __init__(self):
+       dict.__init__(self)
+       self._order = []
+       dict.__setitem__(self, '_order', self._order)
+   def __setitem__(self, key, value):
+       dict.__setitem__(self, key, value)
+       self._order.append(key)
+
+class Base(type):
+   @staticmethod
+   def __prepare__(*args, **kwargs):
+       return ODict()
+
+class Bar(metaclass=Base):
+   """
+   >>> Bar._order
+   ['__module__', '__doc__', 'bar']
+   """
+   @property
+   def bar(self):
+       return 0