Add __getinitargs__ method to util.timezone

If a timezone object is copied, its __reduce__ method is called which in
turn calls __getinitargs__ to get arguments for __init__ on the new
object.
If that function is missing, __init_ is called with too few parameters.

Problem can be triggered by calling copy or untag on UTCTime or GeneralizedTime
or any other object where the native value includes a datetime

Fixes #167

1 files changed, 10 insertions, 0 deletions

diff --git a/asn1crypto/util.py b/asn1crypto/util.py
index 4d743df..7196897 100644
--- a/asn1crypto/util.py
+++ b/asn1crypto/util.py
@@ -161,6 +161,16 @@ if sys.version_info <= (3,):
                 return False
             return self._offset == other._offset
 
+        def __getinitargs__(self):
+            """
+            Called by tzinfo.__reduce__ to support pickle and copy.
+
+            :return:
+                offset and name, to be used for __init__
+            """
+
+            return self._offset, self._name
+
         def tzname(self, dt):
             """
             :param dt: