Issue #1727780: Support loading pickles of random.Random objects created

on 32-bit systems on 64-bit systems, and vice versa. As a consequence
of the change, Random pickles created by Python 2.6 cannot be loaded
in Python 2.5.

Doc/library/random.rst

@@ -80,6 +80,9 @@ Bookkeeping functions:
 
    .. versionadded:: 2.1
 
+   .. versionchanged:: 2.6
+      State values produced in Python 2.6 cannot be loaded into earlier versions.
+
 
 .. function:: setstate(state)
 

Lib/random.py

@@ -83,7 +83,7 @@ class Random(_random.Random):
 
     """
 
-    VERSION = 2     # used by getstate/setstate
+    VERSION = 3     # used by getstate/setstate
 
     def __init__(self, x=None):
         """Initialize an instance.
@@ -120,9 +120,20 @@ def getstate(self):
     def setstate(self, state):
         """Restore internal state from object returned by getstate()."""
         version = state[0]
-        if version == 2:
+        if version == 3:
             version, internalstate, self.gauss_next = state
             super(Random, self).setstate(internalstate)
+        elif version == 2:
+            version, internalstate, self.gauss_next = state
+            # In version 2, the state was saved as signed ints, which causes
+            #   inconsistencies between 32/64-bit systems. The state is
+            #   really unsigned 32-bit ints, so we convert negative ints from
+            #   version 2 to positive longs for version 3.
+            try:
+                internalstate = tuple( long(x) % (2**32) for x in internalstate )
+            except ValueError, e:
+                raise TypeError, e
+            super(Random, self).setstate(internalstate)
         else:
             raise ValueError("state with version %s passed to "
                              "Random.setstate() of version %s" %

Lib/test/test_random.py

@@ -140,6 +140,19 @@ def test_pickling(self):
         restoredseq = [newgen.random() for i in xrange(10)]
         self.assertEqual(origseq, restoredseq)
 
+    def test_bug_1727780(self):
+        # verify that version-2-pickles can be loaded
+        # fine, whether they are created on 32-bit or 64-bit
+        # platforms, and that version-3-pickles load fine.
+        files = [("randv2_32.pck", 780),
+                 ("randv2_64.pck", 866),
+                 ("randv3.pck", 343)]
+        for file, value in files:
+            f = open(test_support.findfile(file),"rb")
+            r = pickle.load(f)
+            f.close()
+            self.assertEqual(r.randrange(1000), value)
+
 class WichmannHill_TestBasicOps(TestBasicOps):
     gen = random.WichmannHill()
 

Misc/ACKS

@@ -395,6 +395,7 @@ Marc-Andre Lemburg
 Mark Levinson
 William Lewis
 Robert van Liere
+Shawn Ligocki
 Martin Ligr
 Christopher Lindblad
 Eric Lindvall

Misc/NEWS

@@ -308,6 +308,11 @@ Core and builtins
 Library
 -------
 
+- Issue #1727780: Support loading pickles of random.Random objects created
+  on 32-bit systems on 64-bit systems, and vice versa. As a consequence
+  of the change, Random pickles created by Python 2.6 cannot be loaded
+  in Python 2.5.
+
 - Issue #1455: The distutils package now supports VS 2005 and VS 2008 for
   both the msvccompiler and cygwincompiler.
 

Modules/_randommodule.c

@@ -319,12 +319,12 @@ random_getstate(RandomObject *self)
 	if (state == NULL)
 		return NULL;
 	for (i=0; i<N ; i++) {
-		element = PyInt_FromLong((long)(self->state[i]));
+		element = PyLong_FromUnsignedLong(self->state[i]);
 		if (element == NULL)
 			goto Fail;
 		PyTuple_SET_ITEM(state, i, element);
 	}
-	element = PyInt_FromLong((long)(self->index));
+	element = PyLong_FromLong((long)(self->index));
 	if (element == NULL)
 		goto Fail;
 	PyTuple_SET_ITEM(state, i, element);
@@ -339,7 +339,8 @@ static PyObject *
 random_setstate(RandomObject *self, PyObject *state)
 {
 	int i;
-	long element;
+	unsigned long element;
+	long index;
 
 	if (!PyTuple_Check(state)) {
 		PyErr_SetString(PyExc_TypeError,
@@ -353,16 +354,16 @@ random_setstate(RandomObject *self, PyObject *state)
 	}
 
 	for (i=0; i<N ; i++) {
-		element = PyInt_AsLong(PyTuple_GET_ITEM(state, i));
+		element = PyLong_AsUnsignedLong(PyTuple_GET_ITEM(state, i));
 		if (element == -1 && PyErr_Occurred())
 			return NULL;
-		self->state[i] = (unsigned long)element;
+		self->state[i] = element & 0xffffffffUL; /* Make sure we get sane state */
 	}
 
-	element = PyInt_AsLong(PyTuple_GET_ITEM(state, i));
-	if (element == -1 && PyErr_Occurred())
+	index = PyLong_AsLong(PyTuple_GET_ITEM(state, i));
+	if (index == -1 && PyErr_Occurred())
 		return NULL;
-	self->index = (int)element;
+	self->index = (int)index;
 
 	Py_INCREF(Py_None);
 	return Py_None;

Tools/msi/msi.py

@@ -933,6 +933,7 @@ def add_files(db):
             lib.add_file("empty.vbs")
             lib.glob("*.uue")
             lib.glob("*.pem")
+            lib.glob("*.pck")
             lib.add_file("readme.txt", src="README")
         if dir=='decimaltestdata':
             lib.glob("*.decTest")