Issue #18560: Fix potential NULL pointer dereference in sum()

diff --cc Misc/NEWS
index 2f387e7475a6aa1b4d806fd89124c0b0570f996e,505fab58209fb58b526f4d1da7c9291fc25794ae..10ea9f7da77283533015038fd9a35f5b6366ed93
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -10,10 -12,8 +10,12 @@@ What's New in Python 3.4.0 Alpha 1
  Core and Builtins
  -----------------
  
+ - Issue #18560: Fix potential NULL pointer dereference in sum().
+ 
 +- Issue #18520: Add a new PyStructSequence_InitType2() function, same than
 +  PyStructSequence_InitType() except that it has a return value (0 on success,
 +  -1 on error).
 +
  - Issue #15905: Fix theoretical buffer overflow in handling of sys.argv[0],
    prefix and exec_prefix if the operation system does not obey MAXPATHLEN.
  

diff --cc Python/bltinmodule.c
Simple merge