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# Bug
# ---
# 
# static PyObject *
# cwr_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
# {
# ...
# 1 indices = PyMem_Malloc(r * sizeof(Py_ssize_t));
# ...
# for (i=0 ; i<r ; i++)
# 2 indices[i] = 0;
# 
# 
# 1. if r=2^30, then r*sizeof(Py_ssize_t)=2^30*2^2=0 (modulo 2^32), so malloc
# allocates a 0 byte buffer
# 2. r=2^30>0, so we write well beyond the buffer's end
# 
# Crash
# -----
# 
# Breakpoint 1, cwr_new (type=0x83392a0 <cwr_type>, args=('AA', 1073741824), kwds=0x0) at ./Modules/itertoolsmodule.c:2684
# 2684 PyObject *pool = NULL;
# ...
# 2703 indices = PyMem_Malloc(r * sizeof(Py_ssize_t));
# (gdb) print r
# 1ドル = 1073741824
# (gdb) print r*4
# 2ドル = 0
# (gdb) c
# Continuing.
# 
# Program received signal SIGSEGV, Segmentation fault.
# 0x0822fdcd in cwr_new (type=0x83392a0 <cwr_type>, args=('AA', 1073741824), kwds=0x0) at ./Modules/itertoolsmodule.c:2710
# 2710 indices[i] = 0;
# 
# OS info
# -------
# 
# % ./python -V
# Python 3.4.1
# 
# % uname -a
# Linux ubuntu 3.8.0-29-generic #42~precise1-Ubuntu SMP Wed Aug 14 15:31:16 UTC 2013 i686 i686 i386 GNU/Linux
# 
 
import itertools as it
it.combinations_with_replacement("AA", 2**30)