GH-25309 enabled SSL_OP_IGNORE_UNEXPECTED_EOF by default, with a comment
that it restores OpenSSL 1.1.1 behavior, but this wasn't quite right.
That option causes OpenSSL to treat transport EOF as the same as
close_notify (i.e. SSL_ERROR_ZERO_RETURN), whereas Python actually has
distinct SSLEOFError and SSLZeroReturnError exceptions. (The latter is
usually mapped to a zero return from read.) In OpenSSL 1.1.1, the ssl
module would raise them for transport EOF and close_notify,
respectively. In OpenSSL 3.0, both act like close_notify.

Fix this by, instead, just detecting SSL_R_UNEXPECTED_EOF_WHILE_READING
and mapping that to the other exception type.

There doesn't seem to have been any unit test of this error, so fill in
the missing one. This had to be done with the BIO path because it's
actually slightly tricky to simulate a transport EOF with Python's fd
based APIs. (If you instruct the server to close the socket, it gets
confused, probably because the server's SSL object is still referencing
the now dead fd?)
(cherry picked from commit 420bbb783b43216cc897dc8914851899db37a31d)

Co-authored-by: David Benjamin <davidben@google.com>

gh-102027: Fix macro name (GH-102124)

This fixes the ssse3 / sse2 detection when sse4 is available.

(cherry picked from commit ea93bde4ece139d4152a59f2c38aa6568559447c)

Co-authored-by: Max Bachmann <kontakt@maxbachmann.de>
Co-authored-by: Oleg Iarygin <oleg@arhadthedev.net>

gh-96931: Fix incorrect results in ssl.SSLSocket.shared_ciphers (GH-96932)
(cherry picked from commit af9c34f6ef8dceb21871206eb3e4d350f6e3d3dc)

Co-authored-by: Benjamin Fogle <benfogle@gmail.com>

(cherry picked from commit 7f01a11199864bcf230b243b99e8a51e9044675d)

Co-authored-by: Raymond Hettinger <rhettinger@users.noreply.github.com>

(cherry picked from commit c74073657e32b8872f91b3bbe1efa9af20adbea9)

Co-authored-by: Timo Ludwig <ti.ludwig@web.de>
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>

GH-102397: Fix segfault from race condition in signal handling (GH-102399)
(cherry picked from commit 1a84cc007e207f2dd61f86a7fc3d86632fdce72f)

Co-authored-by: Kumar Aditya <59607654+kumaraditya303@users.noreply.github.com>
Co-authored-by: Gregory P. Smith <greg@krypto.org>

* gh-102179: Fix `os.dup2` error reporting for negative fds (GH-102180)
(cherry picked from commit c2bd55d26f8eb2850eb9f9026b5d7f0ed1420b65)

Co-authored-by: Alexey Izbyshev <izbyshev@ispras.ru>
Co-authored-by: Kumar Aditya <59607654+kumaraditya303@users.noreply.github.com>

Fix missing 'is' in cmath.log() docstring.
(cherry picked from commit 71f614ef2a3d66213b9cae807cbbc1ed03741221)

Co-authored-by: Owain Davies <116417456+OTheDev@users.noreply.github.com>

(cherry picked from commit 9ef7e75434587fc8f167d73eee5dd9bdca62714b)

Co-authored-by: Dong-hee Na <donghee.na@python.org>

[3.11] gh-99952: [ctypes] fix refcount issues in from_param() result. (GH-100169)

Fixes a reference counting issue with `ctypes.Structure` when a `from_param()` method call is used and the structure size is larger than a C pointer `sizeof(void*)`.

This problem existed for a very long time, but became more apparent in 3.8+ by change likely due to garbage collection cleanup timing changes..
(cherry picked from commit dfad678d7024ab86d265d84ed45999e031a03691)

(cherry picked from commit fa7c37af4936abfe34aa261d6ed9703bc5842ad4)

Co-authored-by: Gregory P. Smith <greg@krypto.org>
Co-authored-by: Yukihiro Nakadaira <yukihiro.nakadaira@gmail.com>
Co-authored-by: Kumar Aditya <59607654+kumaraditya303@users.noreply.github.com>