bpo-38353, bpo-38429: Fix typos introduced by commit
c02b41b1 in
calculate_argv0_path_framework() of getpath.c.

PR #4906 changed the typing.Generic class hierarchy, leaving an
outdated comment in the library reference. User-defined Generic ABCs now
must get a abc.ABCMeta metaclass from something other than typing.Generic
inheritance.

Add missing stat.S_IFDOOR, stat.S_IFPORT, stat.S_IFWHT,
stat.S_ISDOOR, stat.S_ISPORT, and stat.S_ISWHT values to
the Python implementation of the stat module.

bpo-38392, bpo-38426: Fix a compiler warning in gcmodule.c.

Fix also a typo in PYMEM_DEADBYTE macro comment.

* bpo-38379:  when a finalizer resurrects an object,
nothing is actually collected in this run of gc.
Change the stats to relect that truth.

Signed-off-by: Antonio Gutierrez <chibby0ne@gmail.com>

bpo-37531, bpo-38207: On timeout, regrtest no longer attempts to call
`popen.communicate() again: it can hang until all child processes
using stdout and stderr pipes completes. Kill the worker process and
ignores its output.

Reenable test_regrtest.test_multiprocessing_timeout().

bpo-37531: Change also the faulthandler timeout of the main process
from 1 minute to 5 minutes, for Python slowest buildbots.

The implementation of weakref.proxy's methods call back into the Python
API using a borrowed references of the weakly referenced object
(acquired via PyWeakref_GET_OBJECT). This API call may delete the last
reference to the object (either directly or via GC), leaving a dangling
pointer, which can be subsequently dereferenced.

To fix this, claim a temporary ownership of the referenced object when
calling the appropriate method. Some functions because at the moment they
do not need to access the borrowed referent, but to protect against
future changes to these functions, ownership need to be fixed in
all potentially affected methods.

Valgrind emits "Conditional jump or move depends on uninitialised
value(s)" false alarms on GCC builtin strcmp() function. The GCC code
is correct.

Valgrind bug: https://bugs.kde.org/show_bug.cgi?id=264936

It now escapes them with a backslash, as the regular Python interpreter.
Added the "errors" field to the standard streams.

It is similar to the more general code in the gc module, but
here we know the name of the module.



https://bugs.python.org/issue33714



Automerge-Triggered-By: @encukou

Checks also for encryption algorithms methods not supported in different
OSs.
Signed-off-by: Antonio Gutierrez <chibby0ne@gmail.com>

subtract_refs() now pass the parent object to visit_decref() which
pass it to _PyObject_ASSERT(). So if the "is freed" assertion fails,
the parent is used in debug trace, rather than the freed object. The
parent object is more likely to contain useful information. Freed
objects cannot be inspected are are displayed as "<object at xxx is
freed>" with no other detail.

Some objects like Py_None are not initialized with conventional means
that prepare the circular linked list pointers, leaving them unlinked
from the rest of the objects. For those objects, NULL pointers does
not mean that they are freed, so we need to skip the check in those
cases.

In debug mode, PyObject_GC_Track() now calls tp_traverse() of the
object type to ensure that the object is valid: test that objects
visited by tp_traverse() are valid.

Fix pyexpat.c: only track the parser in the GC once the parser is
fully initialized.

Add a newline between the verbose object dump and the Py_FatalError()
logs for readability.

Prior to 3.7, re.escape escaped many characters that don't have
special meaning in Python, but that use to require escaping in other
tools and languages. This commit aims to make it clear which characters
were, but are no longer escaped.

Fix _PyBytesWriter API when Python is built in release mode with
assertions.

bpo-36389, bpo-38376: The _PyObject_CheckConsistency() function is
now also available in release mode. For example, it can be used to
debug a crash in the visit_decref() function of the GC.

Modify the following functions to also work in release mode:

* _PyDict_CheckConsistency()
* _PyObject_CheckConsistency()
* _PyType_CheckConsistency()
* _PyUnicode_CheckConsistency()

Other changes:

* _PyMem_IsPtrFreed(ptr) now also returns 1 if ptr is NULL
  (equals to 0).
* _PyBytesWriter_CheckConsistency() now returns 1 and is only used
  with assert().
* Reorder _PyObject_Dump() to write safe fields first, and only
  attempt to render repr() at the end.

Calling _Py_wfopen() is enough to check if filename is an existing
file or not. There is no need to check first isfile().

The "tmp" variable is no longer used.

The `required` argument to `argparse.add_subparsers` was added in #3027. This PR specifies the earliest version of Python where it is available.


https://bugs.python.org/issue26510



Automerge-Triggered-By: @merwok

KeyError should cause a failure in parsing the encoded word and should be caught and raised as a _InvalidEWError instead.