rename allowed by OS, disallowed by pyfakefs

[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 True:
    os0 = os
    shutil.rmtree(ROOT_PATH)
    os.mkdir(ROOT_PATH)

path0 = ROOT_PATH 
path1 = ROOT_PATH 
component0 = "alpha" 
component1 = "" 
path1 += os.path.sep + component0 
os0.symlink(path0,path1) 
path1 += os.path.sep + component1 
os0.rename(path1,path0) 

pyfakefs raises: OSError: [Errno 21] Is a directory in the fake filesystem: '/Volumes/ramdisk/test'

[mrbean-bremen]

Under Linux shall raise OSError: [Errno 20], but raises OSError: [Errno 21].
Under MacOS shall not raise, but raises OSError: [Errno 21].
Under Windows correctly raises OSError: [Errno 17].