Merge: #2466: ismount now recognizes mount points user can't access.

diff --cc Misc/ACKS
Simple merge

diff --cc Misc/NEWS
index 18b42c7417751d2246a7279870d4325daf5c2bca,974bf1a8628d18f79fa1a9795f2cdc9fde2b62dd..dc73485b19fb349531011981e80b63aa68ef8055
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -76,41 -38,9 +76,44 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #2466: posixpath.ismount now correctly recognizes mount points which
+   the user does not have permission to access.
+ 
 +- Issue #25958: Support "anti-registration" of special methods from
 +  various ABCs, like __hash__, __iter__ or __len__.  All these (and
 +  several more) can be set to None in an implementation class and the
 +  behavior will be as if the method is not defined at all.
 +  (Previously, this mechanism existed only for __hash__, to make
 +  mutable classes unhashable.)  Code contributed by Andrew Barnert and
 +  Ivan Levkivskyi.
 +
 +- Issue #16764: Support keyword arguments to zlib.decompress().  Patch by
 +  Xiang Zhang.
 +
 +- Issue #27736: Prevent segfault after interpreter re-initialization due
 +  to ref count problem introduced in code for Issue #27038 in 3.6.0a3.
 +  Patch by Xiang Zhang.
 +
 +- Issue #25628:  The *verbose* and *rename* parameters for collections.namedtuple
 +  are now keyword-only.
 +
 +- Issue #12345: Add mathemathical constant tau to math and cmath. See also
 +  PEP 628.
 +
 +- Issue #26823: traceback.StackSummary.format now abbreviates large sections of
 +  repeated lines as "[Previous line repeated {count} more times]" (this change
 +  then further affects other traceback display operations in the module). Patch
 +  by Emanuel Barry.
 +
 +- Issue #27664: Add to concurrent.futures.thread.ThreadPoolExecutor()
 +  the ability to specify a thread name prefix.
 +
 +- Issue #27181: Add geometric_mean and harmonic_mean to statistics module.
 +
 +- Issue #27573: code.interact now prints an message when exiting.
 +
 +- Issue #6422: Add autorange method to timeit.Timer objects.
 +
  - Issue #27773: Correct some memory management errors server_hostname in _ssl.wrap_socket().
  
  - Issue #26750: unittest.mock.create_autospec() now works properly for