The current C implementations **crash** if the input includes a surrogate
Unicode code point, which is not possible to encode in UTF-8.

Important notes:

1.  It is possible to pass a non-UTF-8 string as a separator to the
    `.isoformat()` methods.
2.  The pure-Python `datetime.fromisoformat()` implementation accepts
    strings with a surrogate as the separator.

In `datetime.fromisoformat()`, in the special case of non-UTF-8 separators,
this implementation will take a performance hit by making a copy of the
input string and replacing the separator with 'T'.
Co-authored-by: Alexey Izbyshev <izbyshev@ispras.ru>
Co-authored-by: Paul Ganssle <paul@ganssle.io>

Introduce a configure check for strsignal(3) which defines HAVE_STRSIGNAL for
signalmodule.c. Add some common signals on HP-UX. This change applies for
Windows and HP-UX.

bpo-34170, bpo-34207: pymain_read_conf() now sets Py_UTF8Mode to
config->utf8_mode. pymain_read_conf() calls indirectly
Py_DecodeLocale() and Py_EncodeLocale() which depend on Py_UTF8Mode.

Reported by Svace static analyzer.

Reported by Svace static analyzer.

Previously, its behavior was platform-dependent and there was no error checking
under Windows.

Reported by Svace static analyzer.

Reported by Svace static analyzer.

The entry about deprecation of __getitem__ methods of
several classes was placed in the wrong section.

The missing NULL check was reported by Svace static analyzer.

Reported by Svace static analyzer.

If a globals dictionary without a '__builtins__' key is passed to
eval(), a '__builtins__' key will be inserted to the dictionary:

    >>> eval("print('__builtins__' in globals())", {})
    True

(As a result of this behavior, we can use the builtins
print() and globals() even if we passed a dictionary without a
'__builtins__' key to eval().)

bpo-22602: Raise an exception in the UTF-7 decoder for ill-formed sequences starting with "+". (GH-8741)

The UTF-7 decoder now raises UnicodeDecodeError for ill-formed
sequences starting with "+" (as specified in RFC 2152).

This makes the assertion error message more useful, aiding debugging.

Thanks @davidair!

Fix compile errors reported by HP aCC by fixing bugs introduced in 6dc57e2a
which do not cause trouble on clang or GCC.

Patch by Michael Osipov.

The http_response() and https_response() methods of the HTTPErrorProcessor
class have two required parameters, 'request' and 'response'.

Read from data socket to avoid "[SSL] shutdown while in init" exception
during shutdown of the dummy server.
Signed-off-by: Christian Heimes <christian@python.org>


<!-- issue-number: [bpo-34391](https://www.bugs.python.org/issue34391) -->
https://bugs.python.org/issue34391
<!-- /issue-number -->

os.readlink() now accepts path-like and bytes objects on Windows.
Previously, support for path-like and bytes objects was only
implemented on Unix.

This commit also merges Unix and Windows implementations of
os.readlink() in one function and adds basic unit tests to increase
test coverage of the function.

Avoid undefined pointer arithmetic with NULL.

Downstream vendors have started to deprecate weak keys. Update all RSA keys
and DH params to use at least 2048 bits.

Finite field DH param file use RFC 7919 values, generated with

    certtool --get-dh-params --sec-param=high
Signed-off-by: Christian Heimes <christian@python.org>

Follow up to bpo-34270.

Fixes:
```
Lib/test/test_asyncio/test_tasks.py:330: DeprecationWarning: invalid escape sequence \d
  match1 = re.match("^<Task pending name='Task-(\d+)'", repr(t1))
Lib/test/test_asyncio/test_tasks.py:332: DeprecationWarning: invalid escape sequence \d
  match2 = re.match("^<Task pending name='Task-(\d+)'", repr(t2))
```

* SMTP.startssl: Fix doc on keyfile and certfile use

* SMTP.startssl: Add missing keyfile and certfile deprecation notice

* SMTP: Doc grammar fixes

Improves speed by 9 to 10ns per call.