Test case for bug in PyPy or CFFI

test.py

#!/usr/bin/env pypy
from cffi import FFI

ffi = FFI()
ffi.cdef(r'typedef union _cairo_path_data_t cairo_path_data_t; union _cairo_path_data_t {struct {int type;int length;} header;struct {double x, y;} point;};typedef struct cairo_path {int status; union _cairo_path_data_t *data; int num_data;} cairo_path_t;')

def encode_path_ok():
    length = 4
    data = ffi.new('cairo_path_data_t[]', length)
#    path = ffi.new('cairo_path_t *', (0, data, length))
    path = ffi.new('cairo_path_t *', {'status': 0, 'data': data, 'num_data': length})
    return path, data

def encode_path():
    length = 4
    data = ffi.new('cairo_path_data_t[]', length)
    path = ffi.new('cairo_path_t *', (0, data, length))
#    path = ffi.new('cairo_path_t *', {'status': 0, 'data': data, 'num_data': length})
    return path, data


from pprint import pprint

print("Working example")
for i in range(0, 100000):
	path_new, data = encode_path_ok()
        if path_new.data != data:
		raise Exception("Failed on iteration %i" % i)

print("Will fail")
for i in range(0, 100000):
	path_new, data = encode_path()
        if path_new.data != data:
		raise Exception("Failed on iteration %i" % i)