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.

1 files changed, 13 insertions, 2 deletions

diff --git a/Lib/random.py b/Lib/random.py
index ed87ddd..ec0f386 100644
--- a/Lib/random.py
+++ b/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 @@ class Random(_random.Random):
     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" %