Case mismatch from listdir (MacOS only)

[agroce]

import shutil
import pyfakefs.fake_filesystem
import os

ROOT_PATH = "/Volumes/ramdisk/test"

fs = pyfakefs.fake_filesystem.FakeFilesystem()
fs.CreateDirectory('/Volumes')
fs.CreateDirectory('/Volumes/ramdisk')
fs.CreateDirectory('/Volumes/ramdisk/test')
os0 = pyfakefs.fake_filesystem.FakeOsModule(fs)
opener0 = pyfakefs.fake_filesystem.FakeFileOpen(fs)

if False:
    os0 = os
    shutil.rmtree(ROOT_PATH)
    os.mkdir(ROOT_PATH)

component0 = "beta" 
path0 = ROOT_PATH 
path1 = ROOT_PATH 
path0 += os.path.sep + component0 
component0 = "Alpha" 
os0.symlink(path1,path0) 
path1 += os.path.sep + component0 
component0 = "alpha" 
os0.symlink(path0,path1) 
path0 += os.path.sep + component0 
os0.rename(path1,path0) 
result = sorted(os0.listdir(path0)) 

print result

(pyfakefs gives ['Alpha', 'beta'] vs os ['alpha', 'beta']