Launchpad #290254, DateTime/DateTime.py

o Added '__setstate__' to cope with old pickles missing a '_micros'
  attribute;  Python's pickling support was creating a new instance,
  *with* a '_micros' attribute, but not clearing that attribute before
  updating the instance dict with the unpickled state.

doc/CHANGES.txt

@@ -27,10 +27,16 @@ Zope Changes
 
     Bugs Fixed
 
-      - Launchpad ##332168: Connection.py: do not expose DB connection strings
-        through exceptions
+      - Launchpad #290254, DateTime/DateTime.py:
+        added '__setstate__' to cope with old pickles missing a '_micros'
+        attribute;  Python's pickling support was creating a new instance,
+        *with* a '_micros' attribute, but not clearing that attribute before
+        updating the instance dict with the unpickled state.
 
-      - LP/#324876: tighened regex for detecting the charset
+      - Launchpad #332168, Shared/DC/RDBMS/Connection.py:
+        do not expose DB connection strings through exceptions
+
+      - Launchpad #324876: tighened regex for detecting the charset
         from a meta-equiv header
 
       - configure script: setting ZOPE_VERS to '2.11'

lib/python/DateTime/DateTime.py

@@ -353,6 +353,10 @@ class DateTime:
         except:
             raise SyntaxError('Unable to parse %s, %s' % (args, kw))
 
+    def __setstate__(self, state):
+        self.__dict__.clear()  # why doesn't Python's unpickler do this?
+        self.__dict__.update(state)
+
     def _parse_args(self, *args, **kw):
         """Return a new date-time object.
 

lib/python/DateTime/tests/testDateTime.py

@@ -211,14 +211,61 @@ class DateTimeTests(unittest.TestCase):
         self.failUnless(dt != dt1)
         self.failUnless(not (dt == dt1))
 
-    def testUpgradeOldInstances(self):
+    def test_compare_old_instances(self):
         # Compare dates that don't have the _micros attribute yet
+        # (e.g., from old pickles).
         dt = DateTime('1997/1/1')
         dt1 = DateTime('1997/2/2')
+        dt._millis = dt._micros / 1000
         del dt._micros
+        dt1._millis = dt1._micros / 1000
         del dt1._micros
         self.testCompareOperations(dt, dt1)
 
+    def test_compare_old_new_instances(self):
+        # Compare a date without _micros attribute (e.g., from an old
+        # pickle) with one that does.
+        dt = DateTime('1997/1/1')
+        dt1 = DateTime('1997/2/2')
+        dt._millis = dt._micros / 1000
+        del dt._micros
+        self.testCompareOperations(dt, dt1)
+
+    def test_compare_new_old_instances(self):
+        # Compare a date with _micros attribute with one that does not
+        # (e.g., from an old pickle).
+        dt = DateTime('1997/1/1')
+        dt1 = DateTime('1997/2/2')
+        dt1._millis = dt._micros / 1000
+        del dt1._micros
+        self.testCompareOperations(dt, dt1)
+
+    def test_strftime_old_instance(self):
+        # https://bugs.launchpad.net/zope2/+bug/290254
+        # Ensure that dates without _micros attribute (e.g., from old
+        # pickles) still render correctly in strftime.
+        ISO = '2001-10-10T00:00:00+02:00'
+        dt = DateTime(ISO)
+        dt._millis = dt._micros / 1000
+        del dt._micros
+        self.assertEqual(dt.strftime('%Y'), '2001')
+
+        # Now, create one via pickling / unpickling.
+        from cPickle import dumps, loads
+        self.assertEqual(loads(dumps(dt)).strftime('%Y'), '2001')
+
+    def test___setstate___without_micros(self):
+        ISO = '2001-10-10T00:00:00+02:00'
+        dt = DateTime(ISO)
+        micros = dt._micros
+        dt._millis = dt._micros / 1000
+        del dt._micros
+        state = dt.__dict__
+
+        dt1 = DateTime()
+        dt1.__setstate__(state)
+        self.assertEqual(dt1._micros, micros)
+
     def testTZ2(self):
         # Time zone manipulation test 2
         dt = DateTime()