#15421: fix an OverflowError in Calendar.itermonthdates() after datetime.MAXYEAR.  Patch by Cédric Krier.

  tools (dpkg-dev) installed.

(Compiler: Solaris Studio 12.3)

Patch by Jeremy Kloth.

Issue #15842: the SocketIO.{readable,writable,seekable} methods now raise ValueError when the file-like object is closed.
Patch by Alessandro Moura.

on the action's default, reverting it back to previous behavior.  Conversion
is only done on string defaults.

Add a test for this and another test that ensures such type conversions are
only called once.

Cleanup 'k' when the creation of PySTEntryObject fails. ad3824a90261 used to decref 'k' in too many error cases.

Fix out of bounds read in long_new() for empty bytes with an explicit base. int(b'', somebase) calls PyLong_FromString() with char* of length 1 but the function accesses the first argument at offset 1. CID 715359

  when action='append', type='str' and default=[].

Fix null pointer dereferencing in structmember.c PyMember_SetOne() for T_CHAR. _PyUnicode_AsStringAndSize() can return NULL without touching the len argument. Also remove unnecessary PyUnicode_Check(), _PyUnicode_AsStringAndSize() performance the test again. CID 486815

Fixed memory leak in error branch of object_repr which may leak a reference to mod when type_name returns NULL. CID 715371

Fixed memory leak in error branch of parsestrplus. CID 715374 Variable s going out of scope leaks the storage it points to.