merge

diff --cc Lib/functools.py
Simple merge

diff --cc Lib/test/test_functools.py
Simple merge

diff --cc Misc/NEWS
index fbe26da4d8bd899cdaeba9787c0f5ad5a0100329,073a9f7501cb44c5c81af4b3f2db3530099b57cf..24798ce58faf3223e060628e4aa84c276c1cebd9
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -10,17 -10,6 +10,20 @@@ What's New in Python 3.6.1 release cand
  Core and Builtins
  -----------------
  
 +- Issue #26919: On Android, operating system data is now always encoded/decoded
 +  to/from UTF-8, instead of the locale encoding to avoid inconsistencies with
 +  os.fsencode() and os.fsdecode() which are already using UTF-8.
 +
++- Issue #28991:  functools.lru_cache() was susceptible to an obscure $
++  bug triggerable by a monkey-patched len() function.
++
 +- Issue #28147: Fix a memory leak in split-table dictionaries: setattr()
 +  must not convert combined table into split table. Patch written by INADA
 +  Naoki.
 +
 +- Issue #28739: f-string expressions no longer accepted as docstrings and
 +  by ast.literal_eval() even if they do not include expressions.
 +
  - Issue #28512: Fixed setting the offset attribute of SyntaxError by
    PyErr_SyntaxLocationEx() and PyErr_SyntaxLocationObject().