gh-143304: Fix ctypes.CDLL to honor handle parameter on POSIX systems by Koolvansh07 · Pull Request #143318 · python/cpython

Koolvansh07 · 2025-12-31T23:54:28Z

The handle parameter was being ignored in the POSIX implementation of CDLL._load_library(), causing it to always call _dlopen() even when a valid handle was provided. This was a regression introduced in recent refactoring.

This PR adds the missing handle check to match the Windows implementation behavior, and includes a regression test.

Fixes gh-143304

The handle parameter was being ignored in the POSIX implementation of CDLL._load_library(), causing it to always call _dlopen() even when a valid handle was provided. This was a regression introduced in recent refactoring. This commit adds the missing handle check to match the Windows implementation behavior, and includes a regression test. Fixes pythongh-143304

bedevere-app · 2025-12-31T23:54:32Z

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If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

python-cla-bot · 2025-12-31T23:54:32Z

All commit authors signed the Contributor License Agreement.

Lib/test/test_ctypes/test_loading.py

Misc/NEWS.d/next/Library/2026-01-01-05-26-00.gh-issue-143304.Kv7x9Q.rst

Lib/test/test_ctypes/test_loading.py

Lib/ctypes/__init__.py

bedevere-app · 2026-01-01T00:15:42Z

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

- Remove AI-generated comments from test - Use skipIf decorator instead of runtime check - Simplify NEWS entry (don't mention private _dlopen)

test_handle_fix.py

Lib/ctypes/__init__.py

picnixz · 2026-01-01T00:35:29Z

Lib/test/test_ctypes/test_loading.py

+        lib1 = CDLL(libc_name)
+        handle = lib1._handle
+        lib2 = CDLL(name=None, handle=handle)
+        self.assertIs(handle, lib2._handle)


Suggested change

self.assertIs(handle, lib2._handle)

self.assertIs(lib2._handle, handle)

Can you check whether there were tests for Python 3.12 where we had this handle? or if the tests were rewritten as well (see the PRs mentioned on the issue).

I checked the 3.12 branch source code:

Lib/ctypes/__init__.py in 3.12 DID support the handle parameter (it checked if handle is None:).

Lib/test/test_ctypes/test_loading.py in 3.12 DID NOT have any test using CDLL(..., handle=...) on POSIX.

The name parameter may be modified by .fwork and AIX processing, so we need to process it before checking the handle.

addressed

sharktide

LGTM
Thanks for your contribution @Koolvansh07

Koolvansh07 · 2026-01-01T14:01:50Z

LGTM Thanks for your contribution @Koolvansh07

your welcome

serhiy-storchaka

I thought it was Windows-only parameter, but it is documented on Posix too.

LGTM. 👍

bedevere-bot · 2026-02-23T15:34:58Z

🤖 New build scheduled with the buildbot fleet by @encukou for commit cdb8f6e 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F143318%2Fmerge

If you want to schedule another build, you need to add the 🔨 test-with-buildbots label again.

miss-islington-app · 2026-02-24T12:17:02Z

Thanks @Koolvansh07 for the PR, and @encukou for merging it 🌮🎉.. I'm working now to backport this PR to: 3.13, 3.14.
🐍🍒⛏🤖

…ystems (pythonGH-143318) The handle parameter was being ignored in the POSIX implementation of CDLL._load_library(), causing it to always call _dlopen() even when a valid handle was provided. This was a regression introduced in recent refactoring. (cherry picked from commit 27ded243485670fa836c9bb421e37a6ef16eca8e) Co-authored-by: Arjit Singh Grover <143692910+Koolvansh07@users.noreply.github.com>

…ystems (pythonGH-143318) The handle parameter was being ignored in the POSIX implementation of CDLL._load_library(), causing it to always call _dlopen() even when a valid handle was provided. This was a regression introduced in recent refactoring. (cherry picked from commit 27ded24) Co-authored-by: Arjit Singh Grover <143692910+Koolvansh07@users.noreply.github.com>

bedevere-app · 2026-02-24T12:17:18Z

GH-145172 is a backport of this pull request to the 3.14 branch.

bedevere-app · 2026-02-24T12:17:21Z

GH-145173 is a backport of this pull request to the 3.13 branch.

bedevere-app bot added the awaiting review label Dec 31, 2025

bedevere-app bot mentioned this pull request Dec 31, 2025

ctypes.CDLL does no longer honor the handle argument starting Python 3.13.10+ & 3.14.1+? #143304

Closed

Add NEWS entry for pythongh-143304

bb4c92e

picnixz previously requested changes Jan 1, 2026

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Koolvansh07 added 2 commits January 1, 2026 05:52

Address review feedback

d8b9ed3

- Remove AI-generated comments from test - Use skipIf decorator instead of runtime check - Simplify NEWS entry (don't mention private _dlopen)

Move handle check to beginning to avoid unnecessary computation

32eb34d

picnixz reviewed Jan 1, 2026

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test_handle_fix.py Outdated Show resolved Hide resolved

Remove debug files that were accidentally committed

6d95eff

picnixz reviewed Jan 1, 2026

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picnixz reviewed Jan 1, 2026

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Koolvansh07 added 2 commits January 1, 2026 06:06

Move handle check to end of function as suggested by reviewer

d3f65b6

The name parameter may be modified by .fwork and AIX processing, so we need to process it before checking the handle.

Update test assertion to match (actual, expected) convention

cdb8f6e

bedevere-app bot added awaiting review and removed awaiting changes labels Jan 1, 2026

sharktide approved these changes Jan 1, 2026

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serhiy-storchaka requested a review from zooba January 2, 2026 14:47

serhiy-storchaka added needs backport to 3.13 bugs and security fixes needs backport to 3.14 bugs and security fixes labels Jan 2, 2026

serhiy-storchaka approved these changes Jan 2, 2026

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encukou added the 🔨 test-with-buildbots Test PR w/ buildbots; report in status section label Feb 23, 2026

bedevere-bot removed the 🔨 test-with-buildbots Test PR w/ buildbots; report in status section label Feb 23, 2026

encukou added this to Ctypes issues Feb 23, 2026

encukou merged commit 27ded24 into python:main Feb 24, 2026
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	self.assertIs(handle, lib2._handle)
	self.assertIs(lib2._handle, handle)

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