Mirror
/
cpython
mirror of https://github.com/python/cpython
4
1
Fork 0
Code Issues Releases Wiki Activity

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 eda2963378.  Why? this comment buried in an earlier code review explains:

I checked again how that value is used in practice, it's here:

0c80da4c14/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.
This commit is contained in:
Sebastian Pipping 2024-03-06 18:55:07 +01:00 committed by GitHub
parent c012c8ab7b
commit 8a8e9204d1
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Include/pyexpat.h
View File

@ -3,7 +3,7 @@
/* note: you must import expat.h before importing this module! */ /* 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" #define PyExpat_CAPSULE_NAME "pyexpat.expat_CAPI"
struct PyExpat_CAPI struct PyExpat_CAPI