* Make sure that when some of the tests in test_smtplib fail, the allocated threads
and sockets are not leaked. 

* Use support.join_thread() instead of thread.join() to avoid infinite blocks.

Some methods of the SMTP class use mutable default arguments. Specially
`send_message` is affected as it mutates one of the args by appending items
to it, which has side effects on further calls.

* Add %T format to PyUnicode_FromFormatV(), and so to
  PyUnicode_FromFormat() and PyErr_Format(), to format an object type
  name: equivalent to "%s" with Py_TYPE(obj)->tp_name.
* Replace Py_TYPE(obj)->tp_name with %T format in unicodeobject.c.
* Add unit test on %T format.
* Rename unicode_fromformat_write_cstr() to
  unicode_fromformat_write_utf8(), to make the intent more explicit.

Implement the "attributes objects" parameter of `os.posix_spawn` to complete the implementation and fully cover the underlying API.

* Replace "master process" with "parent process"
* Replace "master option mappings" with "main option mappings"
* Replace "master pattern object" with "main pattern object"
* ssl: replace "master" with "server"
* And some other similar changes

Rename also run_tests_slave() to run_tests_worker().

Co-Authored-By: Wouter Bolsterlee.

distutils.spawn.find_executable() now falls back on os.defpath if the
PATH environment variable is not set.

Fail `test_semaphore_tracker_sigint` if no warnings are expected and one is received.

Fix race condition when the child receives SIGINT before it can register signal handlers for it.

The race condition occurs when the parent calls
`_semaphore_tracker.ensure_running()` (which in turn spawns the
semaphore_tracker using `_posixsubprocess.fork_exec`), the child
registers the signal handlers and the parent tries to kill the child.
What seem to happen is that in some slow systems, the parent sends the
signal to kill the child before the child protects against the signal.

math.factorial() was accepting non-integral Decimal instances. This is inconsistent with the actual behaviour for floats, which are not accepted.

* Fix Tools/clinic/clinic_test.py: add missing
  FakeClinic.destination_buffers attribute and pass a file argument
  to Clinic().
* Rename Tools/clinic/clinic_test.py to Lib/test/test_clinic.py:
  add temporary Tools/clinic/ to sys.path to import the clinic
  module.
Co-Authored-By: Pablo Galindo <pablogsal@gmail.com>

* Add _testcapi.get_coreconfig() to get the _PyCoreConfig of the
  interpreter
* test.pythoninfo now gets the core configuration using
  _testcapi.get_coreconfig()

"explicitelly" → "explicitly"

p.wait()

Sometimes some versions of the shared libraries that are part of the
traceback are compiled in optimised mode and the Program Counter (PC)
is not present, not allowing gdb to walk the frames back. When this
happens, the Python bindings of gdb raise an exception, making the
test impossible to succeed.

Move strict_timestamps to constructor.

Update all test certs and keys to use future proof crypto settings:

* 3072 bit RSA keys
* SHA-256 signature
Signed-off-by: Christian Heimes <christian@python.org>

Modify TestPosixSpawn to run Python using -I and -S options.

Disable site module to avoid side effects. For example, on Fedora 28,
if the HOME environment variable is not set, site._getuserbase()
calls pwd.getpwuid() which opens /var/lib/sss/mc/passwd, but then
leaves the file open which makes test_close_file() to fail.

Add support for the "surrogatepass" error handler in
PyUnicode_DecodeFSDefault() and PyUnicode_EncodeFSDefault()
for the UTF-8 encoding.

Changes:

* _Py_DecodeUTF8Ex() and _Py_EncodeUTF8Ex() now support the
  surrogatepass error handler (_Py_ERROR_SURROGATEPASS).
* _Py_DecodeLocaleEx() and _Py_EncodeLocaleEx() now use
  the _Py_error_handler enum instead of "int surrogateescape" to pass
  the error handler. These functions now return -3 if the error
  handler is unknown.
* Add unit tests on _Py_DecodeLocaleEx() and _Py_EncodeLocaleEx()
  in test_codecs.
* Rename get_error_handler() to _Py_GetErrorHandler() and expose it
  as a private function.
* _freeze_importlib doesn't need config.filesystem_errors="strict"
  workaround anymore.

Py_DecodeLocale() and Py_EncodeLocale() now use the UTF-8 encoding on
Windows if Py_LegacyWindowsFSEncodingFlag is zero.

pymain_read_conf() now sets Py_LegacyWindowsFSEncodingFlag in its
loop, but restore its value at exit.

_PyCoreConfig_Read() is now responsible to choose the filesystem
encoding and error handler. Using Py_Main(), the encoding is now
chosen even before calling Py_Initialize().

_PyCoreConfig.filesystem_encoding is now the reference, instead of
Py_FileSystemDefaultEncoding, for the Python filesystem encoding.

Changes:

* Add filesystem_encoding and filesystem_errors to _PyCoreConfig
* _PyCoreConfig_Read() now reads the locale encoding for the file
  system encoding.
* PyUnicode_EncodeFSDefault() and PyUnicode_DecodeFSDefaultAndSize()
  now use the interpreter configuration rather than
  Py_FileSystemDefaultEncoding and Py_FileSystemDefaultEncodeErrors
  global configuration variables.
* Add _Py_SetFileSystemEncoding() and _Py_ClearFileSystemEncoding()
  private functions to only modify Py_FileSystemDefaultEncoding and
  Py_FileSystemDefaultEncodeErrors in coreconfig.c.
* _Py_CoerceLegacyLocale() now takes an int rather than
  _PyCoreConfig for the warning.

* Add stdio_encoding and stdio_errors fields to _PyCoreConfig.
* Add unit tests on stdio_encoding and stdio_errors.

Standard streams like sys.stdout now use the "surrogateescape" error
handler, instead of "strict", on the POSIX locale (when the C locale is not
coerced and the UTF-8 Mode is disabled).

Add tests on sys.stdout.errors with LC_ALL=POSIX.

Python now gets the locale encoding with C code to initialize the encoding
of standard streams like sys.stdout. Moreover, the encoding is now
initialized to the Python codec name to get a normalized encoding name and
to ensure that the codec is loaded. The change avoids importing
_bootlocale and _locale modules at startup by default.

When the PYTHONIOENCODING environment variable only contains an encoding,
the error handler is now is now set explicitly to "strict".

Rename also get_default_standard_stream_error_handler() to
get_stdio_errors().

Reduce the buffer to format the "cpXXX" string (Windows locale encoding).

* The UTF-8 Mode is now also enabled by the "POSIX" locale, not only
  by the "C" locale.
* On FreeBSD, Py_DecodeLocale() and Py_EncodeLocale() now also forces
  the ASCII encoding if the LC_CTYPE locale is "POSIX", not only if
  the LC_CTYPE locale is "C".
* test_utf8_mode.test_cmd_line() checks also that the command line
  arguments are decoded from UTF-8 when the the UTF-8 Mode is enabled
  with POSIX locale or C locale.

Robust caching of calculated properties is
harder than it looks at first glance, so add
a solid, well-tested implementation to the
standard library.

AIX uses ISO-8859-1 encoding for the C locale.

Remove "trace.cover" left from previous test runs before testing
that it is no longer created.

bpo-32968: Make modulo and floor division involving Fraction and float consistent with other operations (#5956)

Make mixed-type `%` and `//` operations involving `Fraction` and `float` objects behave like all other mixed-type arithmetic operations: first the `Fraction` object is converted to a `float`, then the `float` operation is performed as normal. This fixes some surprising corner cases, like `Fraction('1/3') % inf` giving a NaN.

Thanks Elias Zamaria for the patch.

An old apparent AIX behavior workaround in test_subprocess's
test_undecodable_env is no longer needed.

Previously marks stack was upsized even there was space for additional item.

Avoids an integer underflow in the time module's year handling code.