Cannot os.remove a file after calling os.DirEntry.stat() on it

[radoslawg]

Describe the bug
When a os.scandir() is followed by stat() function on a file, pyfakefs refuses to os.remove the file ending with Except.

How To Reproduce
Consider following testcase:

def test_perm_bug(fs):
    fs.create_file('\\phonyDir\\testfile', contents='test')
    x = os.scandir('\\phonyDir')
    for z in x:
        print(z.stat().st_size)
    x.close()
    os.remove('\\phonyDir\\testfile')

it ends with

c:\home\mojepliki\python\dupfinder\lib\site-packages\pyfakefs\fake_filesystem.py:4143: in remove
    self.filesystem.remove(path)
c:\home\mojepliki\python\dupfinder\lib\site-packages\pyfakefs\fake_filesystem.py:3028: in remove
    self.remove_object(norm_path)
c:\home\mojepliki\python\dupfinder\lib\site-packages\pyfakefs\fake_filesystem.py:2295: in remove_object
    target_directory.remove_entry(basename)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <pyfakefs.fake_filesystem.FakeDirectory object at 0x000002D3BC0F3788>
pathname_name = 'testfile', recursive = True

    def remove_entry(self, pathname_name, recursive=True):
        """Removes the specified child file or directory.
    
        Args:
            pathname_name: Basename of the child object to remove.
            recursive: If True (default), the entries in contained directories
                are deleted first. Used to propagate removal errors
                (e.g. permission problems) from contained entries.
    
        Raises:
            KeyError: if no child exists by the specified name.
            OSError: if user lacks permission to delete the file,
                or (Windows only) the file is open.
        """
        pathname_name = self._normalized_entryname(pathname_name)
        entry = self.get_entry(pathname_name)
        if self.filesystem.is_windows_fs:
            if entry.st_mode & PERM_WRITE == 0:
                self.filesystem.raise_os_error(errno.EACCES, pathname_name)
            if self.filesystem.has_open_file(entry):
                self.filesystem.raise_os_error(errno.EACCES, pathname_name)
        else:
            if (not is_root() and (self.st_mode & (PERM_WRITE | PERM_EXE) !=
                                   PERM_WRITE | PERM_EXE)):
                self.filesystem.raise_os_error(errno.EACCES, pathname_name)
    
        if recursive and isinstance(entry, FakeDirectory):
            while entry.contents:
                entry.remove_entry(list(entry.contents)[0])
        elif entry.st_nlink == 1:
            self.filesystem.change_disk_usage(
                -entry.size, pathname_name, entry.st_dev)
    
        self.st_nlink -= 1
        entry.st_nlink -= 1
>       assert entry.st_nlink >= 0
E       assert -1 >= 0
E        +  where -1 = <pyfakefs.fake_filesystem.FakeFile object at 0x000002D3BC0F3548>.st_nlink

c:\home\mojepliki\python\dupfinder\lib\site-packages\pyfakefs\fake_filesystem.py:738: AssertionError

Your enviroment

Windows-10-10.0.18362-SP0
Python 3.7.5 (tags/v3.7.5:5c02a39a0b, Oct 15 2019, 00:11:34) [MSC v.1916 64 bit (AMD64)]
pyfakefs 3.6.1

Workaround is to use os.stat() instead of os.DirEntry.stat() .

[mrbean-bremen]

Thanks for the report - looks really strange...

[radoslawg]

Maybe I'm missing something, but I cannot find any clue in python documentation. Also, it works on real fs, so it seems it is limited only to pyfakefs .

[mrbean-bremen]

Yes, it's a bug in pyfakefs (Windows only) - I'm on it. Good catch!