Repair pickling for Properties object

Fixed bug whereby the ``__getstate__`` / ``__setstate__``
methods for sqlalchemy.util.Properties were
non-working due to the transition in the 1.0 series to ``__slots__``.
The issue potentially impacted some third-party applications.
Pull request courtesy Pieter Mulder.

Fixes: #3728
Change-Id: I01ebd425bbfe145747fea2edd0d2d412c74fd84d
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/286
(cherry picked from commit cab57e9bab04fbdea44690c08dff379a29eaab32)

3 files changed, 47 insertions, 2 deletions

diff --git a/doc/build/changelog/changelog_10.rst b/doc/build/changelog/changelog_10.rst
index 7a41731bf..defee6d06 100644
--- a/doc/build/changelog/changelog_10.rst
+++ b/doc/build/changelog/changelog_10.rst
@@ -20,6 +20,16 @@
 
     .. change::
         :tags: bug, sql
+        :tickets: 3728
+
+        Fixed bug whereby the ``__getstate__`` / ``__setstate__``
+        methods for sqlalchemy.util.Properties were
+        non-working due to the transition in the 1.0 series to ``__slots__``.
+        The issue potentially impacted some third-party applications.
+        Pull request courtesy Pieter Mulder.
+
+    .. change::
+        :tags: bug, sql
         :tickets: 3724
 
         :meth:`.FromClause.count` is pending deprecation for 1.1.  This function
diff --git a/lib/sqlalchemy/util/_collections.py b/lib/sqlalchemy/util/_collections.py
index c29b81f6a..be5d1be44 100644
--- a/lib/sqlalchemy/util/_collections.py
+++ b/lib/sqlalchemy/util/_collections.py
@@ -200,10 +200,10 @@ class Properties(object):
         self._data[key] = obj
 
     def __getstate__(self):
-        return {'_data': self.__dict__['_data']}
+        return {'_data': self._data}
 
     def __setstate__(self, state):
-        self.__dict__['_data'] = state['_data']
+        object.__setattr__(self, '_data', state['_data'])
 
     def __getattr__(self, key):
         try:
diff --git a/test/base/test_utils.py b/test/base/test_utils.py
index fcb9a59a3..7e2473dee 100644
--- a/test/base/test_utils.py
+++ b/test/base/test_utils.py
@@ -2256,3 +2256,38 @@ class TestClassProperty(fixtures.TestBase):
         eq_(B.something, {'foo': 1, 'bazz': 2})
 
 
+class TestProperties(fixtures.TestBase):
+
+    def test_pickle(self):
+        data = {'hello': 'bla'}
+        props = util.Properties(data)
+
+        for loader, dumper in picklers():
+            s = dumper(props)
+            p = loader(s)
+
+            eq_(props._data, p._data)
+            eq_(props.keys(), p.keys())
+
+    def test_pickle_immuatbleprops(self):
+        data = {'hello': 'bla'}
+        props = util.Properties(data).as_immutable()
+
+        for loader, dumper in picklers():
+            s = dumper(props)
+            p = loader(s)
+
+            eq_(props._data, p._data)
+            eq_(props.keys(), p.keys())
+
+    def test_pickle_orderedprops(self):
+        data = {'hello': 'bla'}
+        props = util.OrderedProperties()
+        props.update(data)
+
+        for loader, dumper in picklers():
+            s = dumper(props)
+            p = loader(s)
+
+            eq_(props._data, p._data)
+            eq_(props.keys(), p.keys())