Fix pickling of tzoffset

Fixes#650

Author: xhochy

git/objects/util.py

@@ -105,6 +105,9 @@ def __init__(self, secs_west_of_utc, name=None):
 self._offset=timedelta(seconds=-secs_west_of_utc)
 self._name=nameor'fixed'
 
+def__reduce__(self):
+returntzoffset, (-self._offset.total_seconds(), self._name)
+
 defutcoffset(self, dt):
 returnself._offset
 

git/test/test_util.py

@@ -4,6 +4,7 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
+importpickle
 importtempfile
 importtime
 fromunittestimportskipIf
@@ -280,3 +281,9 @@ def test_from_timestamp(self):
 # Wrong offset: UTC-9000, should return datetime + tzoffset(UTC)
 altz=utctz_to_altz('-9000')
 self.assertEqual(datetime.fromtimestamp(1522827734, tzoffset(0)), from_timestamp(1522827734, altz))
+
+deftest_pickle_tzoffset(self):
+t1=tzoffset(555)
+t2=pickle.loads(pickle.dumps(t1))
+self.assertEqual(t1._offset, t2._offset)
+self.assertEqual(t1._name, t2._name)