Avoid encoding errors with pickle.loads PYTHON-355.

This works around issues caused by applications that use sys.setdefaultencoding to set an interpreter-wide encoding other than ascii or utf8. This is only an issue in python 2.x. In python 3.0 and 3.1 setdefaultencoding is a noop. It was completely removed in python 3.2.

Author: behackett

bson/objectid.py

@@ -32,7 +32,7 @@
 import time
 
 from bson.errors import InvalidId
-from bson.py3compat import (b, binary_type, text_type,
+from bson.py3compat import (PY3, b, binary_type, text_type,
  bytes_from_hex, string_types)
 from bson.tz_util import utc
 
@@ -208,21 +208,18 @@ def __setstate__(self, value):
  """explicit state set from pickling
  """
  # Provide backwards compatability with OIDs
- # pickled with pymongo-1.9.
+ # pickled with pymongo-1.9 or older.
  if isinstance(value, dict):
- try:
- # ObjectIds pickled in python 2.x used `str` for __id.
- # In python 3.x this has to be converted to `bytes`
- # by encoding latin-1.
- self.__id = value['_ObjectId__id'].encode('latin-1')
- except UnicodeDecodeError:
- self.__id = value['_ObjectId__id']
+ oid = value["_ObjectId__id"]
  else:
- try:
- # See the previous comment about python 2/3 pickle issues.
- self.__id = value.encode('latin-1')
- except (UnicodeDecodeError, AttributeError):
- self.__id = value
+ oid = value
+ # ObjectIds pickled in python 2.x used `str` for __id.
+ # In python 3.x this has to be converted to `bytes`
+ # by encoding latin-1.
+ if PY3 and isinstance(oid, text_type):
+ self.__id = oid.encode('latin-1')
+ else:
+ self.__id = oid
 
  def __str__(self):
  return binascii.hexlify(self.__id).decode()