Issue #23914: Fixed SystemError raised by unpickler on broken pickle data.

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

diff --cc Misc/NEWS
index 3297f4ee13afbbeea0c1b1eab06713ccbe860ccc,cdc891e8dddbaa91f3f05a7c22bbfeab8731f90a..fef1a32426fe748deb6425cf67034849eaf21107
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -95,11 -107,6 +95,13 @@@ Core and Builtin
  Library
  -------
  
++- Issue #23914: Fixed SystemError raised by unpickler on broken pickle data.
++
 +- Issue #25691: Fixed crash on deleting ElementTree.Element attributes.
 +
 +- Issue #25624: ZipFile now always writes a ZIP_STORED header for directory
 +  entries.  Patch by Dingyuan Wang.
 +
  - Issue #25626: Change three zlib functions to accept sizes that fit in
    Py_ssize_t, but internally cap those sizes to UINT_MAX.  This resolves a
    regression in 3.5 where GzipFile.read() failed to read chunks larger than 2

diff --cc Modules/_pickle.c
Simple merge