gh-150868: Fix sum() deallocating a float subclass as an exact float - #151063
Open
eendebakpt wants to merge 2 commits into
Open
gh-150868: Fix sum() deallocating a float subclass as an exact float#151063eendebakpt wants to merge 2 commits into
eendebakpt wants to merge 2 commits into
Conversation
…float The complex-total fast path in builtin_sum_impl() guarded with PyFloat_Check() (which accepts subclasses) but freed the item with _Py_DECREF_SPECIALIZED(item, _PyFloat_ExactDealloc), which assumes an exact float. A float subclass instance reaching refcount 0 in that loop aborts on an assertion in debug builds, and in release builds skips the subclass tp_dealloc (type refcount leak, __del__ never runs, subclass object pushed onto the float freelist). Use PyFloat_CheckExact() instead, matching the float-total branch, so subclass instances fall through to the generic PyNumber_Add() path. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
StanFromIreland
changed the title
Contributor
Author
|
There was already a PR opened earlier, lets give that a chance to be merged. |
Member
|
I like this pr, it has a test. @eendebakpt, could you extend this fix with this (and add tests too): |
…) loops Per review: use PyLong_CheckExact with the specialized exact-int deallocator in the float and complex fast-sum loops, so int subclasses take the generic path. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Contributor
Author
|
@skirpichev I updated the branch with your suggestion. I think this will need backports. |
skirpichev
approved these changes
Jul 31, 2026
skirpichev
added
needs backport to 3.13
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Uh oh!
There was an error while loading. Please reload this page.