bpo-30850: On Windows, test04_lock_timeout2() now tolerates 50 ms
whereas 100 ms is expected. The lock sometimes times out after only
58 ms. Windows clocks have a bad resolution and bad accuracy.

(cherry picked from commit cfcd7677)

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)

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

(cherry picked from commit fff2a210)

encoder and decoder.
(cherry picked from commit d3aaa2f1)

(cherry picked from commit 50f58163)

encoder and decoder..
(cherry picked from commit d3aaa2f1)

* [2.7] Avoid _GNU_SOURCE redefined warning in xmlparse.c (GH-2670)
(cherry picked from commit f5232559)

* [2.7] Avoid _GNU_SOURCE redefined warning in xmlparse.c (GH-2670).
(cherry picked from commit f5232559)

If history-length is set in .inputrc, and the history file is double the
history size (or more), history_get(N) returns NULL, and python
segfaults. Fix that by checking for NULL return value.

It seems that the root cause is incorrect handling of bigger history in
readline, but Python should not segfault even if readline returns
unexpected value.

This issue affects only GNU readline. When using libedit emulation
system history size option does not work.

This is a backport of the actual fix from master without the test, since
the test depends on new run_pty() helper which is not available in 2.7.

Replace `dumps` with `json.dumps`

* bpo-30855: Trying to fix test_use on Windows.

Avoid possible weird behavior of WideInt convertion.
"winfo id" always returns string hexadecimal representation.

(cherry picked from commit b9d67249)

* bpo-30855: Trying to fix test_use on Windows.

(cherry picked from commit 29a2f7c6)
(subTest() removed since it was introduced in Python 3)

(cherry picked from commit 76c567ee)

This provides more information on test failures.

list_cases() now unload modules, as the test runner does, to prevent
a failure in test_xpickle about test.pickletester loaded after
loading test_cpickle:

./python -m test --list-cases test_cpickle test_xpickle

Copy Lib/test/test_robotparser.py from master to 2.7 and adapt it for
Python 2.7:

* Replace urllib.robotparser with robotparser
* Adjust HTTPServer import
* Replace io.StringIO with StringIO.StringIO
* Remove tests on crawl_delay() and request_rate() since these
  methods were added to Python 3
* Remove subTest()
* Add test_main() which explicitly lists all test cases

Patch based on the commit 4da0fd06
written by Berker Peksag.
Co-Authored-By: Berker Peksag <berker.peksag@gmail.com>

* Rename again Lib/test/bisectcmd.py to Lib/test/bisect.py
* regrtest now removes '' and Lib/test/ from sys.path
* Use absolute import in test_bisect

Revert test_bisect.py change:
remove "from __future__ import absolute_import".

Sleep 1 ms instead of 0.1 ms to workaround a rounding issue on
Windows. On Windows, time.sleep(0.0001) sleeps 0 ms, so
collect_in_thread() calls gc.collect() in a loop and tests using this
thread takes too long. Sleep 1 ms so time.sleep() sleeps 15.6 ms on
Windows.

FXpy doesn't have a Python 3 port and it only
supports Python 2.2 and older versions.

Reported by Alex Walters on docs@p.o.

(cherry picked from commit d3ed2877)

Write header and "Using seed ..." after checking for --list-cases and
--list-tests.

I thought I had run the full test suite before the last checkin, but
obviously I didn't.  test_multibytecodec_support.py isn't really a test file,
it is a support file that contains a base test class.  Rename it to
multibytecodec_support so that regrtest test discovery doesn't think it is a
test file that should be run..
(cherry picked from commit 75d9aca9)

* bpo-29512, bpo-30764: Backport regrtest enhancements from 3.5 to 2.7

* bpo-29512: Add test.bisect, bisect failing tests (#2452)

Add a new "python3 -m test.bisect" tool to bisect failing tests.

It can be used to find which test method(s) leak references, leak
files, etc.

* bpo-30764: Fix regrtest --fail-env-changed --forever (#2536) (#2539)

--forever now stops if a fail changes the environment.

* Fix test_bisect: use absolute import

Add missing "import subprocess".

Oh, this is my fault too. I missed this mistake. Thank you for the correction.

* bpo-30807: signal.setitimer() may disable the timer by mistake

* Add NEWS blurb.
(cherry picked from commit 729780a8)

* Clear potential ref cycle between Process and Process target

Besides Process.join() not being called, this was an indirect cause of bpo-30775.
The threading module already does this.

* Add issue reference.
(cherry picked from commit 79d37ae9)

Clarify that the break statement breaks out of the innermost enclosing for or while loop.
(cherry picked from commit 36fc8967)

* bpo-30523: regrtest --list-cases --match (#2401)

* regrtest --list-cases now supports --match and --match-file options.
  Example: ./python -m test --list-cases -m FileTests test_os
* --list-cases now also sets support.verbose to False to prevent
  messages to stdout when loading test modules.
* Add support._match_test() private function.
(cherry picked from commit ace56d58)

(cherry picked from commit 36946c06a3bdb1104c53f0fe535086572ffbdd9e)

* bpo-30764: regrtest: add --fail-env-changed option (#2402)

* bpo-30764: regrtest: change exit code on failure

* Exit code 2 if failed tests ("bad")
* Exit code 3 if interrupted

* bpo-30764: regrtest: add --fail-env-changed option

If the option is set, mark a test as failed if it alters the
environment, for example if it creates a file without removing it.

(cherry picked from commit 63f54c68)
(cherry picked from commit 1f33857a3677de84bdc6d80c39f577eb081ed85d)

* bpo-30776: reduce regrtest -R false positives (#2422)

* Change the regrtest --huntrleaks checker to decide if a test file
  leaks or not. Require that each run leaks at least 1 reference.
* Warmup runs are now completely ignored: ignored in the checker test
  and not used anymore to compute the sum.
* Add an unit test for a reference leak.

Example of reference differences previously considered a failure
(leak) and now considered as success (success, no leak):

    [3, 0, 0]
    [0, 1, 0]
    [8, -8, 1]
(cherry picked from commit 48b5c422)

(cherry picked from commit e0f8b43a46850aa5e5992465cab684496f102fe5)

* Add test.support._crash_python() which triggers a crash but uses
  test.support.SuppressCrashReport() to prevent a crash report from
  popping up.
* Modify test_child_terminated_in_stopped_state() of test_subprocess
  and test_crashed() of test_regrtest to use _crash_python().

* Add Windows support to test.support.SuppressCrashReport: call
  SetErrorMode() and CrtSetReportMode().
* _testcapi: add CrtSetReportMode() and CrtSetReportFile() functions
  and CRT_xxx and CRTDBG_xxx constants needed by SuppressCrashReport.

* bpo-30764: Backport support.SuppressCrashReport

Backport test.support.SuppressCrashReport context-manager from
master. Drop the Windows implementation since it depends on
msvcrt.CrtSetReportMode() which isn't available on Python 2.7.

* bpo-30764: test_subprocess uses SuppressCrashReport (#2405)

bpo-30764, bpo-29335: test_child_terminated_in_stopped_state() of
test_subprocess now uses support.SuppressCrashReport() to prevent the
creation of a core dump on FreeBSD.
(cherry picked from commit cdee3f14)