~sschwarzer/ftputil#39: 
isdir and isfile on broken links with special targets cause a PermanentError

If isdir and isfile are used on a link whose target doesn't exist, they raise a PermanentError though they should return False, similar to os.path.isdir/isfile.

Example:

>>> conn=ftputil.FTPHost('mirror3.mirror.garr.it','anonymous','p@p.com')
>>> conn.path.islink("/mirrors/zebra")
True
>>> conn.lstat("/mirrors/zebra")._st_target
'../1/zebra'
>>> conn.path.exists("/mirrors/1")
False
>>> conn.path.isdir("/mirrors/zebra")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "ftp_path.py", line 145, in isdir
    path, _exception_for_missing_path=False)
  File "ftputil.py", line 824, in stat
    return self._stat.stat(path, _exception_for_missing_path)
  File "ftp_stat.py", line 587, in stat
    _exception_for_missing_path)
  File "ftp_stat.py", line 543, in __call_with_parser_retry
    result = method(*args, **kwargs)
  File "ftp_stat.py", line 508, in _real_stat
    lstat_result = self._real_lstat(path, _exception_for_missing_path)
  File "ftp_stat.py", line 460, in _real_lstat
    lines = self._host_dir(dirname)
  File "ftp_stat.py", line 390, in _host_dir
    return self._host._dir(path)
  File "ftputil.py", line 781, in _dir
    descend_deeply=True)
  File "ftputil.py", line 564, in _robust_ftp_command
    self.chdir(path)
  File "ftputil.py", line 587, in chdir
    ftp_error._try_with_oserror(self._session.cwd, path)
  File "ftp_error.py", line 152, in _try_with_oserror
    raise PermanentError(*exc.args)
ftp_error.PermanentError: 550 /1: No such file or directory
Debugging info: ftputil 2.4.2b, Python 2.6.2 (linux2)

One might think that FTPHost.path.exists is broken, but Nautilus 2.26.2 (Gnone file manager) also denotes the link as "(broken)".

Status
RESOLVED DUPLICATE
Submitter
schwa (unverified)
Assigned to
No-one
Submitted
12 years ago
Updated
12 years ago
Labels
bug library

schwa (unverified) 12 years ago · edit

I've just checked in a test case, changeset 884. This tests the path "dir_with_broken_link/nonexistent" (without a directory change beforehand).

Seemingly the whole thing is even a bit more involved. The bug isn't triggered by a mere broken link but only by special ones. For example, these link targets cause tracebacks:

  • nonexistent/nonexistent
  • ../nonexistent/nonexistent
  • /nonexistent/nonexistent
  • ./nonexistent

But these don't:

  • nonexistent
  • ../nonexistent
  • /nonexistent

schwa (unverified) 9 years ago · edit

This issue seems to be a duplicate of that in ticket #66. The traceback looks like it, and the unit test I wrote then for this ticket passes now.

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