bpo-38523: ignore_dangling_symlinks does not apply recursively

[ZackerySpytz]

Fixes #82704.

shutil.copytree() now applies the ignore_dangling_symlinks
argument recursively.

Co-Authored-By: Rob Nelson veaviticus@gmail.com

https://bugs.python.org/issue38523

[github-actions]

This PR is stale because it has been open for 30 days with no activity. Remove stale label or comment or this will be closed in 5 days

[ambv]

This missed the boat for inclusion in Python 3.9 which accepts security fixes only as of today.

[miss-islington]

Thanks @ZackerySpytz for the PR, and @iritkatriel for merging it 🌮🎉.. I'm working now to backport this PR to: 3.10, 3.11.
🐍🍒⛏🤖

[bedevere-bot]

GH-99193 is a backport of this pull request to the 3.11 branch.

[bedevere-bot]

GH-99194 is a backport of this pull request to the 3.10 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 FreeBSD Non-Debug 3.11 has failed when building commit 5f83209.

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/976/builds/521) and take a look at the build logs.
4. Check if the failure is related to this commit (5f83209) 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/976/builds/521

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

== Tests result: ENV CHANGED ==

415 tests OK.

10 slowest tests:

• test_multiprocessing_spawn: 4 min 51 sec
• test_largefile: 4 min 30 sec
• test_multiprocessing_forkserver: 4 min 23 sec
• test_unparse: 4 min 13 sec
• test_tokenize: 4 min 1 sec
• test_concurrent_futures: 3 min 46 sec
• test_asyncio: 3 min 25 sec
• test_lib2to3: 2 min 44 sec
• test_pydoc: 2 min 37 sec
• test_multiprocessing_fork: 2 min 14 sec

1 test altered the execution environment:
test_concurrent_futures

20 tests skipped:
test_dbm_gnu test_devpoll test_epoll test_idle test_ioctl
test_launcher test_msilib test_readline test_spwd test_startfile
test_tcl test_tix test_tk test_ttk_guionly test_ttk_textonly
test_turtle test_winconsoleio test_winreg test_winsound
test_zipfile64

Total duration: 22 min 23 sec

Click to see traceback logs

Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.11.koobs-freebsd-9e36.nondebug/build/Lib/test/test_concurrent_futures.py", line 100, in __del__
    self.event.set()
  File "/usr/home/buildbot/python/3.11.koobs-freebsd-9e36.nondebug/build/Lib/multiprocessing/managers.py", line 1093, in set
    return self._callmethod('set')
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.11.koobs-freebsd-9e36.nondebug/build/Lib/multiprocessing/managers.py", line 818, in _callmethod
    self._connect()
  File "/usr/home/buildbot/python/3.11.koobs-freebsd-9e36.nondebug/build/Lib/multiprocessing/managers.py", line 805, in _connect
    conn = self._Client(self._token.address, authkey=self._authkey)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.11.koobs-freebsd-9e36.nondebug/build/Lib/multiprocessing/connection.py", line 501, in Client
    c = SocketClient(address)
        ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.11.koobs-freebsd-9e36.nondebug/build/Lib/multiprocessing/connection.py", line 629, in SocketClient
    s.connect(address)
FileNotFoundError: [Errno 2] No such file or directory
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