gh-108843: fix ast.unparse for f-string with many quotes

[hauntsaninja]

The core of the issue here is the fallback to repr in _str_literal_helper when we can't find a workable quote type. This works fine for single strings, but doesn't work well for joined strings (since earlier values of the joined string may have been written assuming a different quote). Therefore, in the bad case, we go back and force use of repr with a single quote for all parts of the joined string. The assert checks that repr continues to work the way we expect it to work.

• Issue: ast.unparse is not working correctly for strings with multiple quotes #108843

[miss-islington]

Thanks @hauntsaninja for the PR, and @pablogsal for merging it 🌮🎉.. I'm working now to backport this PR to: 3.12.
🐍🍒⛏🤖

[pablogsal]

Thanks a lot @hauntsaninja !

[bedevere-app]

GH-109541 is a backport of this pull request to the 3.12 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Ubuntu Shared 3.x has failed when building commit 23f9f6f.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/506/builds/5890) and take a look at the build logs.
4. Check if the failure is related to this commit (23f9f6f) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/506/builds/5890

Failed tests:

• test_threading

Failed subtests:

• test_4_daemon_threads - test.test_threading.ThreadJoinOnShutdown.test_4_daemon_threads

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/test/test_threading.py", line 1168, in test_4_daemon_threads
    rc, out, err = assert_python_ok('-c', script)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/test/support/script_helper.py", line 166, in assert_python_ok
    return _assert_python(True, *args, **env_vars)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/test/support/script_helper.py", line 151, in _assert_python
    res.fail(cmd_line)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/test/support/script_helper.py", line 76, in fail
    raise AssertionError("Process return code is %d\n"
AssertionError: Process return code is -11
command line: ['/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/python', '-X', 'faulthandler', '-I', '-c', "if True:\n            import os\n            import random\n            import sys\n            import time\n            import threading\n\n            thread_has_run = set()\n\n            def random_io():\n                '''Loop for a while sleeping random tiny amounts and doing some I/O.'''\n                import test.test_threading as mod\n                while True:\n                    with open(mod.__file__, 'rb') as in_f:\n                        stuff = in_f.read(200)\n                        with open(os.devnull, 'wb') as null_f:\n                            null_f.write(stuff)\n                            time.sleep(random.random() / 1995)\n                    thread_has_run.add(threading.current_thread())\n\n            def main():\n                count = 0\n                for _ in range(40):\n                    new_thread = threading.Thread(target=random_io)\n                    new_thread.daemon = True\n                    new_thread.start()\n                    count += 1\n                while len(thread_has_run) < count:\n                    time.sleep(0.001)\n                # Trigger process shutdown\n                sys.exit(0)\n\n            main()\n            "]

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot ARM Raspbian 3.x has failed when building commit 23f9f6f.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/424/builds/4951) and take a look at the build logs.
4. Check if the failure is related to this commit (23f9f6f) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/424/builds/4951

Failed tests:

• test_subprocess

Failed subtests:

• test_leak_fast_process_del_killed - test.test_subprocess.POSIXProcessTestCase.test_leak_fast_process_del_killed

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/var/lib/buildbot/workers/3.x.gps-raspbian.nondebug/build/Lib/test/test_subprocess.py", line 3128, in test_leak_fast_process_del_killed
    self.assertRaises(OSError, os.waitpid, pid, 0)
AssertionError: OSError not raised by waitpid

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot s390x RHEL7 LTO + PGO 3.x has failed when building commit 23f9f6f.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/244/builds/5460) and take a look at the build logs.
4. Check if the failure is related to this commit (23f9f6f) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/244/builds/5460

Failed tests:

• test.test_asyncio.test_subprocess

Failed subtests:

• test_subprocess_consistent_callbacks - test.test_asyncio.test_subprocess.SubprocessThreadedWatcherTests.test_subprocess_consistent_callbacks

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.lto-pgo/build/Lib/test/test_asyncio/test_subprocess.py", line 788, in test_subprocess_consistent_callbacks
    self.loop.run_until_complete(main())
  File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.lto-pgo/build/Lib/asyncio/base_events.py", line 664, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.lto-pgo/build/Lib/test/test_asyncio/test_subprocess.py", line 780, in main
    self.assertEqual(events, [
AssertionError: Lists differ: [('pi[29 chars]t'), 'pipe_connection_lost', ('pipe_data_recei[57 chars]ted'] != [('pi[29 chars]t'), ('pipe_data_received', 2, b'stderr'), 'pi[57 chars]ted']