[Python-checkins] python/dist/src/Lib pickle.py,1.124,1.125

[gvanrossum@users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Lib
In directory sc8-pr-cvs1:/tmp/cvs-serv25722

Modified Files:
	pickle.py 
Log Message:
In save_newobj(), if an object's __getnewargs__ and __getstate__ are
the same function, don't save the state or write a BUILD opcode.  This
is so that a type (e.g. datetime :-) can support protocol 2 using
__getnewargs__ while also supporting protocol 0 and 1 using
__getstate__.  (Without this, the state would be pickled twice with
protocol 2, unless __getstate__ is defined to return None, which
breaks protocol 0 and 1.)


Index: pickle.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/pickle.py,v
retrieving revision 1.124
retrieving revision 1.125
diff -C2 -d -r1.124 -r1.125
*** pickle.py	29 Jan 2003 20:14:23 -0000	1.124
--- pickle.py	30 Jan 2003 05:39:04 -0000	1.125
***************
*** 417,420 ****
--- 417,443 ----
  
          getstate = getattr(obj, "__getstate__", None)
+ 
+         # A class may define both __getstate__ and __getnewargs__.
+         # If they are the same function, we ignore __getstate__.
+         # This is for the benefit of protocols 0 and 1, which don't
+         # use __getnewargs__.  Note that the only way to make them
+         # the same function is something like this:
+         #
+         #   class C(object):
+         #       def __getstate__(self):
+         #           return ...
+         #       __getnewargs__ = __getstate__
+         #
+         # No tricks are needed to ignore __setstate__; it simply
+         # won't be called when we don't generate BUILD.
+         # Also note that when __getnewargs__ and __getstate__ are
+         # the same function, we don't do the default thing of
+         # looking for __dict__ and slots either -- it is assumed
+         # that __getnewargs__ returns all the state there is
+         # (which should be a safe assumption since __getstate__
+         # returns the *same* state).
+         if getstate and getstate == getnewargs:
+             return
+ 
          if getstate:
              try: