Fix __getstate__ when derived class has slots.

persistent/pyPersistence.py

@@ -262,6 +262,14 @@ class Persistent(object):
             return dict([x for x in idict.items()
                             if not x[0].startswith('_p_') and
                                not x[0].startswith('_v_')])
+        slots = getattr(type(self), '__slots__', None)
+        if slots is not None:
+            slots = [x for x in slots
+                            if not x.startswith('_p_') and
+                               not x.startswith('_v_') and
+                               x not in Persistent.__slots__]
+            if slots:
+                return None, dict([(x, getattr(self, x)) for x in slots])
         return None
 
     def __setstate__(self, state):
@@ -358,6 +366,7 @@ class Persistent(object):
         if self.__jar is not None and self.__oid is not None:
             self.__jar._cache.mru(self.__oid)
 
+
 def _estimated_size_in_24_bits(value):
     if value > 1073741696:
         return 16777215

persistent/tests/test_pyPersistence.py

@@ -701,6 +701,15 @@ class _Persistent_Base(object):
         inst._v_qux = 'spam'
         self.assertEqual(inst.__getstate__(), {'foo': 'bar'})
 
+    def test___getstate___derived_w_slots(self):
+        class Derived(self._getTargetClass()):
+            __slots__ = ('foo', '_p_baz', '_v_qux')
+        inst = Derived()
+        inst.foo = 'bar'
+        inst._p_baz = 'bam'
+        inst._v_qux = 'spam'
+        self.assertEqual(inst.__getstate__(), (None, {'foo': 'bar'}))
+
     def test___setstate___empty(self):
         inst = self._makeOne()
         inst.__setstate__(None) # doesn't raise, but doesn't change anything