https://github.com/python/cpython/commit/8a8e9204d1f737fa5dc6f5087411bdbe8139d3b2 commit: 8a8e9204d1f737fa5dc6f5087411bdbe8139d3b2 branch: main author: Sebastian Pipping <[email protected]> committer: gpshead <[email protected]> date: 2024-03-06T09:55:07-08:00 summary:
gh-115398: Revert `PyExpat_CAPI_MAGIC` version bump (GH-116411) Revert "gh-115398: Increment PyExpat_CAPI_MAGIC for SetReparseDeferralEnabled addition (GH-116301)" This reverts part of commit eda2963378a3c292cf6bb202bb00e94e46ee6d90. Why? this comment buried in an earlier code review explains: I checked again how that value is used in practice, it's here: https://github.com/python/cpython/blob/0c80da4c14d904a367968955544dd6ae58c8101c/Modules/_elementtree.c#L4363-L4372 Based on that code my understanding is that loading bigger structs from the future is considered okay unless `PyExpat_CAPI_MAGIC` differs, which implies that (1) magic needs to stay the same to support loading the future from the past and (2) that `PyExpat_CAPI_MAGIC` should only ever change for changes that do not increase size (but keep it constant). To summarize, that supports your argument. I checked branches 3.8, 3.9, 3.10, 3.11, 3.12 now and they all have the same comparison code there so reverting that magic string bump will support seamless backporting. files: M Include/pyexpat.h diff --git a/Include/pyexpat.h b/Include/pyexpat.h index e0cff33b53227a..9824d099c3df7d 100644 --- a/Include/pyexpat.h +++ b/Include/pyexpat.h @@ -3,7 +3,7 @@ /* note: you must import expat.h before importing this module! */ -#define PyExpat_CAPI_MAGIC "pyexpat.expat_CAPI 1.2" +#define PyExpat_CAPI_MAGIC "pyexpat.expat_CAPI 1.1" #define PyExpat_CAPSULE_NAME "pyexpat.expat_CAPI" struct PyExpat_CAPI _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
