[3.8] bpo-38532: Add missing decrefs in PyCFuncPtr_FromDll() (GH-16857)

[miss-islington]

(cherry picked from commit e02ab59)

Co-authored-by: Zackery Spytz zspytz@gmail.com

https://bugs.python.org/issue38532

Automerge-Triggered-By: @Yhg1s

[miss-islington]

@ZackerySpytz and @Yhg1s: Status check is done, and it's a success ✅ .

[miss-islington]

@ZackerySpytz and @Yhg1s: Status check is done, and it's a success ✅ .

[miss-islington]

@ZackerySpytz and @Yhg1s: Status check is done, and it's a success ✅ .

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 FreeBSD Shared 3.8 has failed when building commit aa3efea.

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/18/builds/58) and take a look at the build logs.
4. Check if the failure is related to this commit (aa3efea) 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/18/builds/58

Failed tests:

• test_imaplib

Failed subtests:

• test_logout - test.test_imaplib.NewIMAPTests

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

== Tests result: FAILURE then ENV CHANGED ==

402 tests OK.

10 slowest tests:

• test_tokenize: 7 min 57 sec
• test_tools: 7 min 28 sec
• test_multiprocessing_spawn: 6 min 57 sec
• test_lib2to3: 6 min 7 sec
• test_concurrent_futures: 4 min 44 sec
• test_multiprocessing_forkserver: 4 min 35 sec
• test_multiprocessing_fork: 3 min 46 sec
• test_asyncio: 3 min 44 sec
• test_subprocess: 3 min 13 sec
• test_regrtest: 2 min 44 sec

1 test altered the execution environment:
test_asyncio

20 tests skipped:
test_dbm_gnu test_devpoll test_epoll test_gdb test_idle test_ioctl
test_msilib test_ossaudiodev 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

1 re-run test:
test_imaplib

Total duration: 28 min 36 sec

Click to see traceback logs

Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.8.koobs-freebsd-564d/build/Lib/test/test_imaplib.py", line 471, in test_logout
    typ, data = client.login('user', 'pass')
  File "/usr/home/buildbot/python/3.8.koobs-freebsd-564d/build/Lib/imaplib.py", line 601, in login
    typ, dat = self._simple_command('LOGIN', user, self._quote(password))
  File "/usr/home/buildbot/python/3.8.koobs-freebsd-564d/build/Lib/imaplib.py", line 1205, in _simple_command
    return self._command_complete(name, self._command(name, *args))
  File "/usr/home/buildbot/python/3.8.koobs-freebsd-564d/build/Lib/imaplib.py", line 1022, in _command_complete
    typ, data = self._get_tagged_response(tag, expect_bye=logout)
  File "/usr/home/buildbot/python/3.8.koobs-freebsd-564d/build/Lib/imaplib.py", line 1148, in _get_tagged_response
    self._get_response()
  File "/usr/home/buildbot/python/3.8.koobs-freebsd-564d/build/Lib/imaplib.py", line 1050, in _get_response
    resp = self._get_line()
  File "/usr/home/buildbot/python/3.8.koobs-freebsd-564d/build/Lib/imaplib.py", line 1158, in _get_line
    line = self.readline()
  File "/usr/home/buildbot/python/3.8.koobs-freebsd-564d/build/Lib/imaplib.py", line 314, in readline
    line = self.file.readline(_MAXLINE + 1)
  File "/usr/home/buildbot/python/3.8.koobs-freebsd-564d/build/Lib/socket.py", line 669, in readinto
    return self._sock.recv_into(b)
ConnectionResetError: [Errno 54] Connection reset by peer