bpo-32960: For dataclasses, disallow inheriting frozen from non-frozen classes and vice-versa, (GH-5919)

This restriction will be relaxed at a future date.

When comprehensions switched to using a nested scope, the old
code for generating a temporary name to hold the accumulation
target became redundant, but was never actually removed.

Patch by Nitish Chandra.

unsafe_hash=False is now the default. It is the same behavior as the old hash=None parameter. unsafe_hash=True will try to add __hash__. If it already exists, TypeError is raised.

Fixes https://github.com/python/core-workflow/issues/223

By default `print` adds spaces between its arguments.

* Support sendfile on Windows Proactor event loop naively.

This code never did anything correct or useful. The class attribute will never be affected, and the condition will never be true.

Signed-off-by: Christian Heimes <christian@python.org>

The ctypes module used to depend on indirect linking for dlopen. The shared
extension is now explicitly linked against libdl on platforms with dl.
Signed-off-by: Christian Heimes <christian@python.org>

Add tests to verify connection with secp384r1 ECDH curves.

The 'optimization' is for space in the executable file, not for run time.

The ssl module now detects missing NPN support in LibreSSL.
Co-Authored-By: Bernard Spil <brnrd@FreeBSD.org>
Signed-off-by: Christian Heimes <christian@python.org>

* The SSLSocket is no longer implemented on top of SSLObject to
  avoid an extra level of indirection.
* Owner and session are now handled in the internal constructor.
* _ssl._SSLSocket now uses the same method names as SSLSocket and
  SSLObject.
* Channel binding type check is now handled in C code. Channel binding
  is always available.

The patch also changes the signature of SSLObject.__init__(). In my
opinion it's fine. A SSLObject is not a user-constructable object.
SSLContext.wrap_bio() is the only valid factory.

obmalloc has (empty) macros for locking in the allocator. These aren't needed in CPython; we rely on the GIL.

ssl.match_hostname() has been simplified and no longer depends on re and
ipaddress module for wildcard and IP addresses. Error reporting for invalid
wildcards has been improved.
Signed-off-by: Christian Heimes <christian@python.org>

Adjust tests and user modules to match.

Previously, the ssl module stored international domain names (IDNs)
as U-labels. This is problematic for a number of reasons -- for
example, it made it impossible for users to use a different version
of IDNA than the one built into Python.

After this change, we always convert to A-labels as soon as possible,
and use them for all internal processing. In particular, server_hostname
attribute is now an A-label, and on the server side there's a new
sni_callback that receives the SNI servername as an A-label rather than
a U-label.

Changed the template to be inside a comment tag.

Exhaustively test dataclass hashing when no hash= value is provided. This is in anticipation of changing how non-default hashing is handled. (#5834)

`whilst` and `while` are both english words, `whilst` is not as commonly used.
This can be confusing to readers whose primary language is not english.

Make test.support.temp_cwd() fork-safe. The context manager test.support.temp_cwd() no longer removes the temporary directory when executing in a process other than the parent it entered from.
If a forked child exits the context manager it won't do the cleanup.

Co-authored-by: Mark Shannon <mark@hotpy.org>
Co-authored-by: Antoine Pitrou <antoine@python.org>

bpo-32556: nt._getfinalpathname, nt._getvolumepathname and nt._getdiskusage now correctly convert from bytes. (GH-5761)

dump is similar to print but less flexible.  lastopenbracketpos is now always initialized in _study2, as was stmt_bracketing, so the class settings are not needed.  get_last_open_bracket_pos is never called.