Merge

diff --cc Misc/NEWS
index 66bdb03a2ca04ea2e94df195fc9d0ec230a87443,e9cd8c7781e1d6aaa0fb22df017ef702d90d67d4..8a5510fd121d984bbba04bfe756c3192fdbbc0e0
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -173,6 -211,17 +173,9 @@@ Librar
  - Issue #1602133: on Mac OS X a shared library build (``--enable-shared``)
    now fills the ``os.environ`` variable correctly.
  
 -- Issue #14471: Fix a possible buffer overrun in the winreg module.
 -
 -Library
 --------
 -
+ - Issue #15505: `unittest.installHandler` no longer assumes SIGINT handler is
+   set to a callable object.
+ 
 -- Issue #12004: Fix an internal error in PyZipFile when writing an invalid
 -  Python file.  Patch by Ben Morgan.
 -
  - Issue #9290: In IDLE the sys.std* streams now implement io.TextIOBase
    interface and support all mandatory methods and properties.