use tempdir if no usable ipython_dir is found

add test for gh-669, and ignore nonexistent toy paths in other path tests.

IPython/utils/path.py

@@ -1,452 +1,466 b''
 # encoding: utf-8
 """
 Utilities for path handling.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import sys
+import tempfile
 from hashlib import md5
 
 import IPython
 from IPython.utils import warn
 from IPython.utils.process import system
 from IPython.utils.importstring import import_item
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 fs_encoding = sys.getfilesystemencoding()
 
 def _cast_unicode(s, enc=None):
     """Turn 8-bit strings into unicode."""
     if isinstance(s, bytes):
         enc = enc or sys.getdefaultencoding()
         return s.decode(enc)
     return s
 
 
 def _get_long_path_name(path):
     """Dummy no-op."""
     return path
 
 def _writable_dir(path):
     """Whether `path` is a directory, to which the user has write access."""
     return os.path.isdir(path) and os.access(path, os.W_OK)
 
 if sys.platform == 'win32':
     def _get_long_path_name(path):
         """Get a long path name (expand ~) on Windows using ctypes.
 
         Examples
         --------
 
         >>> get_long_path_name('c:\\docume~1')
         u'c:\\\\Documents and Settings'
 
         """
         try:
             import ctypes
         except ImportError:
             raise ImportError('you need to have ctypes installed for this to work')
         _GetLongPathName = ctypes.windll.kernel32.GetLongPathNameW
         _GetLongPathName.argtypes = [ctypes.c_wchar_p, ctypes.c_wchar_p,
             ctypes.c_uint ]
 
         buf = ctypes.create_unicode_buffer(260)
         rv = _GetLongPathName(path, buf, 260)
         if rv == 0 or rv > 260:
             return path
         else:
             return buf.value
 
 
 def get_long_path_name(path):
     """Expand a path into its long form.
 
     On Windows this expands any ~ in the paths. On other platforms, it is
     a null operation.
     """
     return _get_long_path_name(path)
 
 
 def get_py_filename(name):
     """Return a valid python filename in the current directory.
 
     If the given name is not a file, it adds '.py' and searches again.
     Raises IOError with an informative message if the file isn't found."""
 
     name = os.path.expanduser(name)
     if not os.path.isfile(name) and not name.endswith('.py'):
         name += '.py'
     if os.path.isfile(name):
         return name
     else:
         raise IOError,'File `%s` not found.' % name
 
 
 def filefind(filename, path_dirs=None):
     """Find a file by looking through a sequence of paths.
 
     This iterates through a sequence of paths looking for a file and returns
     the full, absolute path of the first occurence of the file.  If no set of
     path dirs is given, the filename is tested as is, after running through
     :func:`expandvars` and :func:`expanduser`.  Thus a simple call::
 
         filefind('myfile.txt')
 
     will find the file in the current working dir, but::
 
         filefind('~/myfile.txt')
 
     Will find the file in the users home directory.  This function does not
     automatically try any paths, such as the cwd or the user's home directory.
     
     Parameters
     ----------
     filename : str
         The filename to look for.
     path_dirs : str, None or sequence of str
         The sequence of paths to look for the file in.  If None, the filename
         need to be absolute or be in the cwd.  If a string, the string is
         put into a sequence and the searched.  If a sequence, walk through
         each element and join with ``filename``, calling :func:`expandvars`
         and :func:`expanduser` before testing for existence.
         
     Returns
     -------
     Raises :exc:`IOError` or returns absolute path to file.
     """
     
     # If paths are quoted, abspath gets confused, strip them...
     filename = filename.strip('"').strip("'")
     # If the input is an absolute path, just check it exists
     if os.path.isabs(filename) and os.path.isfile(filename):
         return filename
         
     if path_dirs is None:
         path_dirs = ("",)
     elif isinstance(path_dirs, basestring):
         path_dirs = (path_dirs,)
         
     for path in path_dirs:
         if path == '.': path = os.getcwdu()
         testname = expand_path(os.path.join(path, filename))
         if os.path.isfile(testname):
             return os.path.abspath(testname)
         
     raise IOError("File %r does not exist in any of the search paths: %r" % 
                   (filename, path_dirs) )
 
 
 class HomeDirError(Exception):
     pass
 
 
 def get_home_dir():
     """Return the closest possible equivalent to a 'home' directory.
 
     * On POSIX, we try $HOME.
     * On Windows we try:
       - %HOMESHARE%
       - %HOMEDRIVE\%HOMEPATH%
       - %USERPROFILE%
       - Registry hack for My Documents
       - %HOME%: rare, but some people with unix-like setups may have defined it
     * On Dos C:\
  
     Currently only Posix and NT are implemented, a HomeDirError exception is
     raised for all other OSes.
     """
 
     env = os.environ
 
     # first, check py2exe distribution root directory for _ipython.
     # This overrides all. Normally does not exist.
 
     if hasattr(sys, "frozen"): #Is frozen by py2exe
         if '\\library.zip\\' in IPython.__file__.lower():#libraries compressed to zip-file
             root, rest = IPython.__file__.lower().split('library.zip')
         else: 
             root=os.path.join(os.path.split(IPython.__file__)[0],"../../")
         root=os.path.abspath(root).rstrip('\\')
         if _writable_dir(os.path.join(root, '_ipython')):
             os.environ["IPYKITROOT"] = root
         return _cast_unicode(root, fs_encoding)
 
     if os.name == 'posix':
         # Linux, Unix, AIX, OS X
         try:
             homedir = env['HOME']
         except KeyError:
             # Last-ditch attempt at finding a suitable $HOME, on systems where
             # it may not be defined in the environment but the system shell
             # still knows it - reported once as:
             # https://github.com/ipython/ipython/issues/154
             from subprocess import Popen, PIPE
             homedir = Popen('echo $HOME', shell=True, 
                             stdout=PIPE).communicate()[0].strip()
             if homedir:
                 return _cast_unicode(homedir, fs_encoding)
             else:
                 raise HomeDirError('Undefined $HOME, IPython cannot proceed.')
         else:
             return _cast_unicode(homedir, fs_encoding)
     elif os.name == 'nt':
         # Now for win9x, XP, Vista, 7?
         # For some strange reason all of these return 'nt' for os.name.
         # First look for a network home directory. This will return the UNC
         # path (\\server\\Users\%username%) not the mapped path (Z:\). This
         # is needed when running IPython on cluster where all paths have to 
         # be UNC.
         try:
             homedir = env['HOMESHARE']
         except KeyError:
             pass
         else:
             if _writable_dir(homedir):
                 return _cast_unicode(homedir, fs_encoding)
 
         # Now look for a local home directory
         try:
             homedir = os.path.join(env['HOMEDRIVE'],env['HOMEPATH'])
         except KeyError:
             pass
         else:
             if _writable_dir(homedir):
                 return _cast_unicode(homedir, fs_encoding)
 
         # Now the users profile directory
         try:
             homedir = os.path.join(env['USERPROFILE'])
         except KeyError:
             pass
         else:
             if _writable_dir(homedir):
                 return _cast_unicode(homedir, fs_encoding)
 
         # Use the registry to get the 'My Documents' folder.
         try:
             import _winreg as wreg
             key = wreg.OpenKey(
                 wreg.HKEY_CURRENT_USER,
                 "Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders"
             )
             homedir = wreg.QueryValueEx(key,'Personal')[0]
             key.Close()
         except:
             pass
         else:
             if _writable_dir(homedir):
                 return _cast_unicode(homedir, fs_encoding)
 
         # A user with a lot of unix tools in win32 may have defined $HOME.
         # Try this as a last ditch option.
         try:
             homedir = env['HOME']
         except KeyError:
             pass
         else:
             if _writable_dir(homedir):
                 return _cast_unicode(homedir, fs_encoding)
 
         # If all else fails, raise HomeDirError
         raise HomeDirError('No valid home directory could be found')
     elif os.name == 'dos':
         # Desperate, may do absurd things in classic MacOS. May work under DOS.
         return u'C:\\'
     else:
         raise HomeDirError('No valid home directory could be found for your OS')
 
 def get_xdg_dir():
     """Return the XDG_CONFIG_HOME, if it is defined and exists, else None.
     
     This is only for posix (Linux,Unix,OS X, etc) systems.
     """
 
     env = os.environ
     
     if os.name == 'posix':
         # Linux, Unix, AIX, OS X
         # use ~/.config if not set OR empty
         xdg = env.get("XDG_CONFIG_HOME", None) or os.path.join(get_home_dir(), '.config')
         if xdg and _writable_dir(xdg):
             return _cast_unicode(xdg, fs_encoding)
     
     return None
     
 
 def get_ipython_dir():
     """Get the IPython directory for this platform and user.
     
     This uses the logic in `get_home_dir` to find the home directory
     and the adds .ipython to the end of the path.
     """
     
     env = os.environ
     pjoin = os.path.join
     
     
     ipdir_def = '.ipython'
     xdg_def = 'ipython'
     
     home_dir = get_home_dir()
     xdg_dir = get_xdg_dir()
     # import pdb; pdb.set_trace()  # dbg
     ipdir = env.get('IPYTHON_DIR', env.get('IPYTHONDIR', None))
     if ipdir is None:
         # not set explicitly, use XDG_CONFIG_HOME or HOME
         home_ipdir = pjoin(home_dir, ipdir_def)
         if xdg_dir:
             # use XDG, as long as the user isn't already
             # using $HOME/.ipython and *not* XDG/ipython
             
             xdg_ipdir = pjoin(xdg_dir, xdg_def)
         
             if _writable_dir(xdg_ipdir) or not _writable_dir(home_ipdir):
                 ipdir = xdg_ipdir
         
         if ipdir is None:
             # not using XDG
             ipdir = home_ipdir
 
     ipdir = os.path.normpath(os.path.expanduser(ipdir))
 
+    if os.path.exists(ipdir) and not _writable_dir(ipdir):
+        # ipdir exists, but is not writable
+        warn.warn("IPython dir '%s' is not a writable location,"
+                        " using a temp directory."%ipdir)
+        ipdir = tempfile.mkdtemp()
+    elif not os.path.exists(ipdir):
+        parent = ipdir.rsplit(os.path.sep, 1)[0]
+        if not _writable_dir(parent):
+            # ipdir does not exist and parent isn't writable
+            warn.warn("IPython parent '%s' is not a writable location,"
+                        " using a temp directory."%parent)
+            ipdir = tempfile.mkdtemp()
+
     return _cast_unicode(ipdir, fs_encoding)
 
 
 def get_ipython_package_dir():
     """Get the base directory where IPython itself is installed."""
     ipdir = os.path.dirname(IPython.__file__)
     return _cast_unicode(ipdir, fs_encoding)
 
 
 def get_ipython_module_path(module_str):
     """Find the path to an IPython module in this version of IPython.
 
     This will always find the version of the module that is in this importable
     IPython package. This will always return the path to the ``.py``
     version of the module.
     """
     if module_str == 'IPython':
         return os.path.join(get_ipython_package_dir(), '__init__.py')
     mod = import_item(module_str)
     the_path = mod.__file__.replace('.pyc', '.py')
     the_path = the_path.replace('.pyo', '.py')
     return _cast_unicode(the_path, fs_encoding)
 
 
 def expand_path(s):
     """Expand $VARS and ~names in a string, like a shell
 
     :Examples:
     
        In [2]: os.environ['FOO']='test'
 
        In [3]: expand_path('variable FOO is $FOO')
        Out[3]: 'variable FOO is test'
     """
     # This is a pretty subtle hack. When expand user is given a UNC path
     # on Windows (\\server\share$\%username%), os.path.expandvars, removes
     # the $ to get (\\server\share\%username%). I think it considered $
     # alone an empty var. But, we need the $ to remains there (it indicates
     # a hidden share).
     if os.name=='nt':
         s = s.replace('$\\', 'IPYTHON_TEMP')
     s = os.path.expandvars(os.path.expanduser(s))
     if os.name=='nt':
         s = s.replace('IPYTHON_TEMP', '$\\')
     return s
 
 
 def target_outdated(target,deps):
     """Determine whether a target is out of date.
 
     target_outdated(target,deps) -> 1/0
 
     deps: list of filenames which MUST exist.
     target: single filename which may or may not exist.
 
     If target doesn't exist or is older than any file listed in deps, return
     true, otherwise return false.
     """
     try:
         target_time = os.path.getmtime(target)
     except os.error:
         return 1
     for dep in deps:
         dep_time = os.path.getmtime(dep)
         if dep_time > target_time:
             #print "For target",target,"Dep failed:",dep # dbg
             #print "times (dep,tar):",dep_time,target_time # dbg
             return 1
     return 0
 
 
 def target_update(target,deps,cmd):
     """Update a target with a given command given a list of dependencies.
 
     target_update(target,deps,cmd) -> runs cmd if target is outdated.
 
     This is just a wrapper around target_outdated() which calls the given
     command if target is outdated."""
 
     if target_outdated(target,deps):
         system(cmd)
 
 def filehash(path):
     """Make an MD5 hash of a file, ignoring any differences in line
     ending characters."""
     with open(path, "rU") as f:
         return md5(f.read()).hexdigest()
 
 # If the config is unmodified from the default, we'll just delete it.
 # These are consistent for 0.10.x, thankfully. We're not going to worry about
 # older versions.
 old_config_md5 = {'ipy_user_conf.py': 'fc108bedff4b9a00f91fa0a5999140d3',
                   'ipythonrc': '12a68954f3403eea2eec09dc8fe5a9b5'}
 
 def check_for_old_config(ipython_dir=None):
     """Check for old config files, and present a warning if they exist.
 
     A link to the docs of the new config is included in the message.
 
     This should mitigate confusion with the transition to the new
     config system in 0.11.
     """
     if ipython_dir is None:
         ipython_dir = get_ipython_dir()
 
     old_configs = ['ipy_user_conf.py', 'ipythonrc', 'ipython_config.py']
     warned = False
     for cfg in old_configs:
         f = os.path.join(ipython_dir, cfg)
         if os.path.exists(f):
             if filehash(f) == old_config_md5.get(cfg, ''):
                 os.unlink(f)
             else:
                 warn.warn("Found old IPython config file %r (modified by user)"%f)
                 warned = True
     
     if warned:
         warn.info("""
   The IPython configuration system has changed as of 0.11, and these files will
   be ignored. See http://ipython.github.com/ipython-doc/dev/config for details
   of the new config system.
   To start configuring IPython, do `ipython profile create`, and edit
   `ipython_config.py` in <ipython_dir>/profile_default.
   If you need to leave the old config files in place for an older version of
   IPython and want to suppress this warning message, set
   `c.InteractiveShellApp.ignore_old_config=True` in the new config.""")
 

IPython/utils/tests/test_path.py

@@ -1,371 +1,403 b''
 # encoding: utf-8
 """Tests for IPython.utils.path.py"""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import shutil
 import sys
 import tempfile
+import StringIO
 
 from os.path import join, abspath, split
 
 import nose.tools as nt
 
 from nose import with_setup
 
 import IPython
 from IPython.testing import decorators as dec
 from IPython.testing.decorators import skip_if_not_win32, skip_win32
-from IPython.utils import path
+from IPython.utils import path, io
 
 # Platform-dependent imports
 try:
     import _winreg as wreg
 except ImportError:
     #Fake _winreg module on none windows platforms
     import new
     sys.modules["_winreg"] = new.module("_winreg")
     import _winreg as wreg
     #Add entries that needs to be stubbed by the testing code
     (wreg.OpenKey, wreg.QueryValueEx,) = (None, None)
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 env = os.environ
 TEST_FILE_PATH = split(abspath(__file__))[0]
 TMP_TEST_DIR = tempfile.mkdtemp()
 HOME_TEST_DIR = join(TMP_TEST_DIR, "home_test_dir")
 XDG_TEST_DIR = join(HOME_TEST_DIR, "xdg_test_dir")
 IP_TEST_DIR = join(HOME_TEST_DIR,'.ipython')
 #
 # Setup/teardown functions/decorators
 #
 
 def setup():
     """Setup testenvironment for the module:
     
             - Adds dummy home dir tree
     """
     # Do not mask exceptions here.  In particular, catching WindowsError is a
     # problem because that exception is only defined on Windows...
     os.makedirs(IP_TEST_DIR)
     os.makedirs(os.path.join(XDG_TEST_DIR, 'ipython'))
 
 
 def teardown():
     """Teardown testenvironment for the module:
     
             - Remove dummy home dir tree
     """
     # Note: we remove the parent test dir, which is the root of all test
     # subdirs we may have created.  Use shutil instead of os.removedirs, so
     # that non-empty directories are all recursively removed.
     shutil.rmtree(TMP_TEST_DIR)
 
 
 def setup_environment():
     """Setup testenvironment for some functions that are tested 
     in this module. In particular this functions stores attributes
     and other things that we need to stub in some test functions.
     This needs to be done on a function level and not module level because 
     each testfunction needs a pristine environment.
     """
     global oldstuff, platformstuff
     oldstuff = (env.copy(), os.name, path.get_home_dir, IPython.__file__)
 
     if os.name == 'nt':
         platformstuff = (wreg.OpenKey, wreg.QueryValueEx,)
 
 
 def teardown_environment():
     """Restore things that were remebered by the setup_environment function
     """
     (oldenv, os.name, path.get_home_dir, IPython.__file__,) = oldstuff
+    reload(path)
         
     for key in env.keys():
         if key not in oldenv:
             del env[key]
     env.update(oldenv)
     if hasattr(sys, 'frozen'):
         del sys.frozen
     if os.name == 'nt':
         (wreg.OpenKey, wreg.QueryValueEx,) = platformstuff
 
 # Build decorator that uses the setup_environment/setup_environment
 with_environment = with_setup(setup_environment, teardown_environment)
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_1():
     """Testcase for py2exe logic, un-compressed lib
     """
     sys.frozen = True
     
     #fake filename for IPython.__init__
     IPython.__file__ = abspath(join(HOME_TEST_DIR, "Lib/IPython/__init__.py"))
     
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_2():
     """Testcase for py2exe logic, compressed lib
     """
     sys.frozen = True
     #fake filename for IPython.__init__
     IPython.__file__ = abspath(join(HOME_TEST_DIR, "Library.zip/IPython/__init__.py")).lower()
     
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR).lower())
 
 
 @with_environment
 @skip_win32
 def test_get_home_dir_3():
     """Testcase $HOME is set, then use its value as home directory."""
     env["HOME"] = HOME_TEST_DIR
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, env["HOME"])
 
 
 @with_environment
 @skip_win32
 def test_get_home_dir_4():
     """Testcase $HOME is not set, os=='posix'. 
     This should fail with HomeDirError"""
     
     os.name = 'posix'
     if 'HOME' in env: del env['HOME']
     nt.assert_raises(path.HomeDirError, path.get_home_dir)
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_5():
     """Using HOMEDRIVE + HOMEPATH, os=='nt'.
 
     HOMESHARE is missing.
     """
 
     os.name = 'nt'
     env.pop('HOMESHARE', None)
     env['HOMEDRIVE'], env['HOMEPATH'] = os.path.splitdrive(HOME_TEST_DIR)
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_6():
     """Using USERPROFILE, os=='nt'.
 
     HOMESHARE, HOMEDRIVE, HOMEPATH are missing.
     """
 
     os.name = 'nt'
     env.pop('HOMESHARE', None)
     env.pop('HOMEDRIVE', None)
     env.pop('HOMEPATH', None)
     env["USERPROFILE"] = abspath(HOME_TEST_DIR)
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_7():
     """Using HOMESHARE, os=='nt'."""
 
     os.name = 'nt'
     env["HOMESHARE"] = abspath(HOME_TEST_DIR)
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
     
 # Should we stub wreg fully so we can run the test on all platforms?
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_8():
     """Using registry hack for 'My Documents', os=='nt'
     
     HOMESHARE, HOMEDRIVE, HOMEPATH, USERPROFILE and others are missing.
     """
     os.name = 'nt'
     # Remove from stub environment all keys that may be set
     for key in ['HOME', 'HOMESHARE', 'HOMEDRIVE', 'HOMEPATH', 'USERPROFILE']:
         env.pop(key, None)
 
     #Stub windows registry functions
     def OpenKey(x, y):
         class key:
             def Close(self):
                 pass
         return key()
     def QueryValueEx(x, y):
         return [abspath(HOME_TEST_DIR)]
 
     wreg.OpenKey = OpenKey
     wreg.QueryValueEx = QueryValueEx
 
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
 
 @with_environment
 def test_get_ipython_dir_1():
     """test_get_ipython_dir_1, Testcase to see if we can call get_ipython_dir without Exceptions."""
     env_ipdir = os.path.join("someplace", ".ipython")
+    path._writable_dir = lambda path: True
     env['IPYTHON_DIR'] = env_ipdir
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, env_ipdir)
 
 
 @with_environment
 def test_get_ipython_dir_2():
     """test_get_ipython_dir_2, Testcase to see if we can call get_ipython_dir without Exceptions."""
     path.get_home_dir = lambda : "someplace"
+    path.get_xdg_dir = lambda : None
+    path._writable_dir = lambda path: True
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, os.path.join("someplace", ".ipython"))
 
 @with_environment
 def test_get_ipython_dir_3():
     """test_get_ipython_dir_3, use XDG if defined, and .ipython doesn't exist."""
     path.get_home_dir = lambda : "someplace"
+    path._writable_dir = lambda path: True
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env['XDG_CONFIG_HOME'] = XDG_TEST_DIR
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, os.path.join(XDG_TEST_DIR, "ipython"))
 
 @with_environment
 def test_get_ipython_dir_4():
     """test_get_ipython_dir_4, use XDG if both exist."""
     path.get_home_dir = lambda : HOME_TEST_DIR
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env['XDG_CONFIG_HOME'] = XDG_TEST_DIR
     xdg_ipdir = os.path.join(XDG_TEST_DIR, "ipython")
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, xdg_ipdir)
 
 @with_environment
 def test_get_ipython_dir_5():
     """test_get_ipython_dir_5, use .ipython if exists and XDG defined, but doesn't exist."""
     path.get_home_dir = lambda : HOME_TEST_DIR
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env['XDG_CONFIG_HOME'] = XDG_TEST_DIR
     os.rmdir(os.path.join(XDG_TEST_DIR, 'ipython'))
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, IP_TEST_DIR)
 
 @with_environment
 def test_get_ipython_dir_6():
     """test_get_ipython_dir_6, use XDG if defined and neither exist."""
-    path.get_home_dir = lambda : 'somehome'
-    path.get_xdg_dir = lambda : 'somexdg'
+    xdg = os.path.join(HOME_TEST_DIR, 'somexdg')
+    os.mkdir(xdg)
+    shutil.rmtree(os.path.join(HOME_TEST_DIR, '.ipython'))
+    path.get_home_dir = lambda : HOME_TEST_DIR
+    path.get_xdg_dir = lambda : xdg
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
-    xdg_ipdir = os.path.join("somexdg", "ipython")
+    env.pop('XDG_CONFIG_HOME', None)
+    xdg_ipdir = os.path.join(xdg, "ipython")
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, xdg_ipdir)
 
 @with_environment
 def test_get_ipython_dir_7():
     """test_get_ipython_dir_7, test home directory expansion on IPYTHON_DIR"""
+    path._writable_dir = lambda path: True
     home_dir = os.path.expanduser('~')
     env['IPYTHON_DIR'] = os.path.join('~', 'somewhere')
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, os.path.join(home_dir, 'somewhere'))
 
 
 @with_environment
 def test_get_xdg_dir_1():
     """test_get_xdg_dir_1, check xdg_dir"""
     reload(path)
+    path._writable_dir = lambda path: True
     path.get_home_dir = lambda : 'somewhere'
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     
     nt.assert_equal(path.get_xdg_dir(), os.path.join('somewhere', '.config'))
 
 
 @with_environment
 def test_get_xdg_dir_1():
     """test_get_xdg_dir_1, check nonexistant xdg_dir"""
     reload(path)
     path.get_home_dir = lambda : HOME_TEST_DIR
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     nt.assert_equal(path.get_xdg_dir(), None)
 
 @with_environment
 def test_get_xdg_dir_2():
     """test_get_xdg_dir_2, check xdg_dir default to ~/.config"""
     reload(path)
     path.get_home_dir = lambda : HOME_TEST_DIR
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     cfgdir=os.path.join(path.get_home_dir(), '.config')
     os.makedirs(cfgdir)
     
     nt.assert_equal(path.get_xdg_dir(), cfgdir)
 
 def test_filefind():
     """Various tests for filefind"""
     f = tempfile.NamedTemporaryFile()
     # print 'fname:',f.name
     alt_dirs = path.get_ipython_dir()
     t = path.filefind(f.name, alt_dirs)
     # print 'found:',t
 
 
 def test_get_ipython_package_dir():
     ipdir = path.get_ipython_package_dir()
     nt.assert_true(os.path.isdir(ipdir))
 
 
 def test_get_ipython_module_path():
     ipapp_path = path.get_ipython_module_path('IPython.frontend.terminal.ipapp')
     nt.assert_true(os.path.isfile(ipapp_path))
 
 
 @dec.skip_if_not_win32
 def test_get_long_path_name_win32():
     p = path.get_long_path_name('c:\\docume~1')
     nt.assert_equals(p,u'c:\\Documents and Settings') 
 
 
 @dec.skip_win32
 def test_get_long_path_name():
     p = path.get_long_path_name('/usr/local')
     nt.assert_equals(p,'/usr/local')
 
+@with_environment
+def test_not_writable_ipdir():
+    tmpdir = tempfile.mkdtemp()
+    os.name = "posix"
+    env.pop('IPYTHON_DIR', None)
+    env.pop('IPYTHONDIR', None)
+    env.pop('XDG_CONFIG_HOME', None)
+    env['HOME'] = tmpdir
+    ipdir = os.path.join(tmpdir, '.ipython')
+    os.mkdir(ipdir)
+    os.chmod(ipdir, 600)
+    stderr = io.stderr
+    pipe = StringIO.StringIO()
+    io.stderr = pipe
+    ipdir = path.get_ipython_dir()
+    io.stderr.flush()
+    io.stderr = stderr
+    nt.assert_true('WARNING' in pipe.getvalue())
+    env.pop('IPYTHON_DIR', None)
+    
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