(cherry picked from commit 7762e4d3)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

(cherry picked from commit d6d44327)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

Fixed also testing the "always" warning filter.
(cherry picked from commit b796e7dc)
Co-authored-by: Sergey Fedoseev <fedoseev.sergey@gmail.com>

(cherry picked from commit 2a9b8bab).
(cherry picked from commit 7c43b801503c802ed6ea4b811f5bc73791249d94)

Make the change where discussing the CPython implementation of lists and dicts.
(cherry picked from commit 8d412780)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

(cherry picked from commit 9c5ba097)
Co-authored-by: Marcin Niemira <marcin@niemira.net>

[2.7] bpo-33804: Document that the argument for io.TextIOBase.read() is optional (GH-7510). (GH-8171)

(cherry picked from commit b6bb77c2)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

The Opera Browser was using a outdated command line invocation that resulted in an incorrect URL being opened in the browser when requested using the webbrowser module.

* Correct the arguments passed to the Opera Browser when opening a new URL..
(cherry picked from commit 3cf1f154)
Co-authored-by: Bumsik Kim <k.bumsik@gmail.com>

Most of the change involves fixing up the test suite, which previously made
the assumption that there wouldn't be a new line if the input didn't end in
one.

Contributed by Ammar Askar.

(cherry picked from commit c4ef4896)

(cherry picked from commit fc05e68d)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

(cherry picked from commit b4588c2f)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

(cherry picked from commit 831c2972)
Co-authored-by: Sergey Fedoseev <fedoseev.sergey@gmail.com>

When hunting memory leaks using -R 3:3, test_imap_unordered() of
test_multiprocessing leaks randomly a few memory blocks. It is a
false alarm: when testing using -R 3:20 for example, no leak is
detected.

Modify test_imap_unordered() to be closer to test_imap():

* Only test 10 numbers instead of 1000: it's a pool of 4 processes, so
  10 is enough to test at least one number per process
* Use chunksize=100 instead of chunksize=53 to mimick test_imap()

(cherry picked from commit 23401fb9)

Fix passing lists and tuples of strings containing special characters
'"', '\\', '{', '}' and '\n' as options to tkinter.ttk widgets.
(cherry picked from commit 5bb5bbfc)

(cherry picked from commit 23db935b)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

(cherry picked from commit 62b6cea6)
Co-authored-by: Srinivas Reddy Thatiparthy (శ్రీనివాస్ రెడ్డి తాటిపర్తి) <srinivasreddy@users.noreply.github.com>

(cherry picked from commit 4e21100f)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

* bpo-33718: regrtest: use format_duration() to display failed tests (GH-7686)

* Enhance also format_duration(): work on integers and rounds towards
  +infinity (math.ceil).
* Write unit tests on format_duration()

(cherry picked from commit 4ffe9c2b)

* bpo-33873: regrtest: Add warning on -R 1:3 (GH-7736)

regrtest: Add warning when using less than 3 warmup runs like -R 1:3.

(cherry picked from commit cac4fef8)

* bpo-33873: Fix bug in `runtest.py` and add checks for invalid `-R` parameters (GH-7735)

Fix bug in `Lib/test/libregrtest/runtest.py` that makes running tests an extra time than the specified number of runs.

Add check for invalid --huntrleaks/-R parameters.

(cherry picked from commit 58ed7307)

(cherry picked from commit 4a6e7460)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

Adds references to info about file modes, `time.strftime()`, string formatting
syntaxes, and logging levels.

(cherry picked from commit a8ddf85a)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

(cherry picked from commit c45cb479074b5d25f0d382d3109f527520a9f03c)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

(cherry picked from commit 38cf49bf)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

(cherry picked from commit 9ac11a75)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

The statement is true for Windows (and macOS) also..
(cherry picked from commit c9d43c70)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

Add -g to LDFLAGS when compiling with LTO to get debug symbols.

Set the openssl version to 1.0.2o and fix compiling Tcl.

Fix test_gdbm.test_reorganize() on macOS with gdbm 1.15: add a
larger value to make sure that the file size changes.

(cherry picked from commit 13c79c677f9ec9437c82eda72fa1c2d288d8fceb)

(cherry picked from commit 71ca738f4cd2696d056d0cdb83bebd576f98ccc2)
Co-authored-by: Xiang Zhang <angwerzx@126.com>

(cherry picked from commit 5092439c)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

Make it the same as when one runs 'python'..
(cherry picked from commit 9d49f850)
Co-authored-by: Stéphane Wirtel <stephane@wirtel.be>

Mention that it can be triggered by triple quotes and after specifying decorators.
(cherry picked from commit 68680035)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

" ... access to elements is O(1)."

(cherry picked from commit 7469ff50)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

Fix comparison between signed and unsigned integers. Example of fixed
warning:

Modules\_sre.c(838): warning C4018: '<' : signed/unsigned mismatch

(cherry picked from commit 1fa174a4)

* bpo-32962: python-gdb catchs ValueError on read_var() (GH-7692)

python-gdb now catchs ValueError on read_var(): when Python has no
debug symbols for example.

(cherry picked from commit 019d33b7)

* bpo-32962: python-gdb catchs UnicodeDecodeError (GH-7693)

python-gdb now catchs UnicodeDecodeError exceptions when calling
string().

(cherry picked from commit d22fc0bc)

bpo-29367: python-gdb.py now supports also method-wrapper
(wrapperobject) objects.

(cherry picked from commit 61108333)