#1669: don't allow shutil.rmtree() to be called on a symlink.

Doc/library/shutil.rst

@@ -101,18 +101,24 @@ copying and removal. For operations on individual files, see also the
 
    .. index:: single: directory; deleting
 
-   Delete an entire directory tree (*path* must point to a directory). If
+   Delete an entire directory tree; *path* must point to a directory (but not a
-   *ignore_errors* is true, errors resulting from failed removals will be ignored;
+   symbolic link to a directory).  If *ignore_errors* is true, errors resulting
-   if false or omitted, such errors are handled by calling a handler specified by
+   from failed removals will be ignored; if false or omitted, such errors are
-   *onerror* or, if that is omitted, they raise an exception.
+   handled by calling a handler specified by *onerror* or, if that is omitted,
+   they raise an exception.
 
-   If *onerror* is provided, it must be a callable that accepts three parameters:
+   If *onerror* is provided, it must be a callable that accepts three
-   *function*, *path*, and *excinfo*. The first parameter, *function*, is the
+   parameters: *function*, *path*, and *excinfo*. The first parameter,
-   function which raised the exception; it will be :func:`os.listdir`,
+   *function*, is the function which raised the exception; it will be
-   :func:`os.remove` or :func:`os.rmdir`.  The second parameter, *path*, will be
+   :func:`os.path.islink`, :func:`os.listdir`, :func:`os.remove` or
-   the path name passed to *function*.  The third parameter, *excinfo*, will be the
+   :func:`os.rmdir`.  The second parameter, *path*, will be the path name passed
-   exception information return by :func:`sys.exc_info`.  Exceptions raised by
+   to *function*.  The third parameter, *excinfo*, will be the exception
-   *onerror* will not be caught.
+   information return by :func:`sys.exc_info`.  Exceptions raised by *onerror*
+   will not be caught.
+
+   .. versionchanged:: 2.6
+      Explicitly check for *path* being a symbolic link and raise :exc:`OSError`
+      in that case.
 
 
 .. function:: move(src, dst)

Lib/shutil.py

@@ -156,6 +156,14 @@ def rmtree(path, ignore_errors=False, onerror=None):
     elif onerror is None:
         def onerror(*args):
             raise
+    try:
+        if os.path.islink(path):
+            # symlinks to directories are forbidden, see bug #1669
+            raise OSError("Cannot call rmtree on a symbolic link")
+    except OSError:
+        onerror(os.path.islink, path, sys.exc_info())
+        # can't continue even if onerror hook returns
+        return
     names = []
     try:
         names = os.listdir(path)

Lib/test/test_shutil.py

@@ -149,6 +149,20 @@ class TestShutil(unittest.TestCase):
                 except OSError:
                     pass
 
+        def test_rmtree_on_symlink(self):
+            # bug 1669.
+            os.mkdir(TESTFN)
+            try:
+                src = os.path.join(TESTFN, 'cheese')
+                dst = os.path.join(TESTFN, 'shop')
+                os.mkdir(src)
+                os.symlink(src, dst)
+                self.assertRaises(OSError, shutil.rmtree, dst)
+            finally:
+                shutil.rmtree(TESTFN, ignore_errors=True)
+
+
+
 def test_main():
     test_support.run_unittest(TestShutil)
 

Misc/NEWS

@@ -369,6 +369,9 @@ Core and builtins
 Library
 -------
 
+- #1669: don't allow shutil.rmtree() to be called on a symlink to a
+  directory.
+
 - #1664522: in urllib, don't read non-existing directories in ftp mode,
   returning a 0-byte file -- raise an IOError instead.