* In configdialog: Document causal pathways in create_page_general.
Move related functions to follow this. Simplify some attribute names.
* In test_configdialog: Add tests for load and helplist functions.
Coverage for the general tab is now complete, and 63% overall.
(cherry picked from commit 2bc8f0e6)

The new class manages pairs of tk Variables and trace callbacks.
It is completely covered by new tests.
(cherry picked from commit 45bf723c)

* bpo-30980: Fix close test to fail

test_close_twice was not considering the fact that file_wrapper is
duping the file descriptor. Closing the original descriptor left the
duped one open, hiding the fact that close protection is not effective.

* bpo-30980: Fix double close protection

Invalidated self.fd before closing, handling correctly the case when
os.close raises.

* bpo-30980: Fix fd leak introduced in the fixed test

* Enable building MSI, zip and nuget packages when Py_OutDir is set.

* Restore the --build option, which got reverted at some point.

* Ensure output directory is created.

* Enables BuildForDaily and DailyBuildVersion options for nuget package.

* [3.6] bpo-30822: Fix testing of datetime module. (GH-2530) (GH-2783)

Only C implementation was tested.
(cherry picked from commit 287c5594)

* [3.6] bpo-30822: Fix testing of datetime module. (GH-2530) (GH-2783)

Only C implementation was tested..
(cherry picked from commit 287c5594)

(cherry picked from commit 627d2c8e)

* bpo-30595: Fix multiprocessing.Queue.get(timeout) (#2027)

multiprocessing.Queue.get() with a timeout now polls its reader in
non-blocking mode if it succeeded to aquire the lock but the acquire
took longer than the timeout.
Co-Authored-By: Grzegorz Grzywacz <grzgrzgrz3@gmail.com>
(cherry picked from commit 1b7863c3)

* bpo-30595: Increase test_queue_feeder_donot_stop_onexc() timeout (#2148)

_test_multiprocessing.test_queue_feeder_donot_stop_onexc() now uses a
timeout of 1 second on Queue.get(), instead of 0.1 second, for slow
buildbots.
(cherry picked from commit 8f6eeaf2)

* bpo-30845: reap_children() now logs warnings

* bpo-30845: Enhance test_concurrent_futures cleanup

In setUp() and tearDown() methods of test_concurrent_futures tests,
make sure that tests don't leak threads nor processes. Clear
explicitly the reference to the executor to make it that it's
destroyed (to prevent "dangling threads" warning).

(cherry picked from commit 3df9dec4)

* bpo-26762: Avoid daemon process in _test_multiprocessing (#2842)

test_level() of _test_multiprocessing._TestLogging now uses regular
processes rather than daemon processes to prevent zombi processes
(to not "leak" processes).
(cherry picked from commit 06634950)

* test_multiprocessing: Fix dangling process/thread (#2850)

bpo-26762: Fix more dangling processes and threads in
test_multiprocessing:

* Queue: call close() followed by join_thread()
* Process: call join() or self.addCleanup(p.join)
(cherry picked from commit d7e64d99)

* test_multiprocessing detects dangling per test case (#2841)

bpo-26762: test_multiprocessing now detects dangling processes and
threads per test case classes:

* setUpClass()/tearDownClass() of mixin classes now check if
  multiprocessing.process._dangling or threading._dangling was
  modified to detect "dangling" processses and threads.
* ManagerMixin.tearDownClass() now also emits a warning if it still
  has more than one active child process after 5 seconds.
* tearDownModule() now checks for dangling processes and threads
  before sleep 500 ms. And it now only sleeps if there is a least one
  dangling process or thread.
(cherry picked from commit ffb49408)

* bpo-26762: test_multiprocessing close more queues (#2855)

* Close explicitly queues to make sure that we don't leave dangling
  threads
* test_queue_in_process(): remove unused queue
* test_access() joins also the process to fix a random warning
(cherry picked from commit b4c52966)

* bpo-31019: Fix multiprocessing.Process.is_alive() (#2875)

multiprocessing.Process.is_alive() now removes the process from the
_children set if the process completed.

The change prevents leaking "dangling" processes.
(cherry picked from commit 2db64823)

* bpo-31034: Reliable signal handler for test_asyncio

Don't rely on the current SIGHUP signal handler, make sure that it's
set to the "default" signal handler: SIG_DFL.

* Add comments

(cherry picked from commit 83008091)

(cherry picked from commit 67ba4fa4)

(cherry picked from commit 39243779)

I found a tiny typo in the curses how-to: changed 'Thy' to 'The' on line 68.
(cherry picked from commit d439d3e2)

tearDown() now clears explicitly the self.server variable to make
sure that the thread is completely cleared when tearDownClass()
checks if all threads have been cleaned up.

Fix the following warning:

$ ./python -m test --fail-env-changed -m test.test_os.TestSendfile.test_keywords -R 3:1 test_os
(...)
Warning -- threading_cleanup() failed to cleanup 0 threads after 3 sec (count: 0, dangling: 2)
(...)
Tests result: ENV CHANGED
(cherry picked from commit d1cc037d)

In configdialog: Document causal pathways in create_font_tab docstring.  Simplify some attribute names. Move set_samples calls to var_changed_font (idea from Cheryl Sabella).  Move related functions to positions after the create widgets function.

In test_configdialog: Fix test_font_set so not order dependent.  Fix renamed test_indent_scale so it tests the widget.  Adjust tests for movement of set_samples call.  Add tests for load functions.  Put all font tests in one class and tab indent tests in another.  Except for two lines, these tests completely cover the related functions.
(cherry picked from commit 77e97ca9)

(cherry picked from commit 4c7532e9)

* Document causal event pathways in docstring.
* Simplify some attribute names.
* Rename test_bold_toggle_set_samples to make test_font_set fail.
* Fix test_font_set so not order dependent.
* Fix renamed test_indent_scale so it tests the widget.
(cherry picked from commit 07ba305a)

Make test_shutil test_disk_usage not depend on the current working directory's filesystem.
(cherry picked from commit 529746c9)

Verify that clicking the bold checkbutton and calling its command, set_samples, changes the bold setting of both samples. Simplify some names in configdialog.
(cherry picked from commit d0969d69)
(Incorporates changes and fixes from PRs 2798,  7c5798eb, and 2810, 616ecf18)

* Fix broken test with PR2798 and PR2810 changes.

Cython will, in the right circumstances, offer a MethodType instance
where im_func is a builtin function. Any instance of MethodType is
automatically assumed to be a Python-defined function (more
specifically, a function that has an inspectable signature), but
_set_signature was still conservative in its assumptions. As a result
_set_signature would return early with None instead of a mock since
the im_func had no inspectable signature. This causes problems
deeper inside mock, as _set_signature is assumed to _always_
return a mock, and nothing checked its return value.

In similar corner cases, autospec will simply not check the spec of the
function, so _set_signature is amended to now return early with the
original, not-wrapped mock object.

Patch by Aaron Gallagher.

(cherry picked from commit 856cbcc1)

Use sys.modules.get() in the "with _ModuleLockManager(name):" block
to protect the dictionary key with the module lock and use an atomic
get to prevent race condition.

Remove also _bootstrap._POPULATE since it was unused
(_bootstrap_external now has its own _POPULATE object), add a new
_SENTINEL object instead.
(cherry picked from commit e72b1359)

Adds a new 'Pip not installed' section that covers
running `ensurepip` manually, and also references
the relevant section of the Python Packaging User
Guide.

(cherry picked from commit b3527bfe)

(cherry picked from commit a54a8f18)

When running the test suite using --use=all / -u all, exclude tzdata
since it makes test_datetime too slow (15-20 min on some buildbots)
which then times out on some buildbots.

-u tzdata must now be enabled explicitly, -u tzdata or -u all,tzdata,
to run all test_datetime tests.

Fix also regrtest command line parser to allow passing -u
extralargefile to run test_zipfile64.

Travis CI: remove -tzdata. Replace -u all,-tzdata,-cpu with -u all,-cpu since tzdata is now excluded from -u all.
(cherry picked from commit 5b392bba)

(cherry picked from commit fff2a210)

Patch by Louie Lu.
(cherry picked from commit f776eb0f)
(includes diffs of  ed014f7e and 9f9192af)
* fix config reset from pr 2754

* Fix test_get_font (from pr 2769)

Adds alternate download approach for nuget.exe
Fall back to git.exe if no Python is found. (#2739)
Also check whether git.exe is on PATH if it will be used.
Add support for HOST_PYTHON variable.
Clear internal environment variables used in find_python.bat
Use HOST_PYTHON as the actual Python if it is recent enough.
Adds HOST_PYTHON variable to AppVeyor configuration

(cherry picked from commit 4ed5ad79)

Version v3.6.2

(cherry picked from commit 49f6449e)

instead of failing with SystemError.

Relative import from non-package now fails with ImportError rather than
SystemError.
(cherry picked from commit 8a9cd20e)

* Add section to idlelib/idle-test/README.txt.
* Include check that branches are taken both ways.
* Exclude IDLE-specific code that does not run during unit tests.
(cherry picked from commit 95bebb72)

(cherry picked from commit 50f58163)

backport