mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-10-10 00:43:41 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 18

[3.12] gh-106052: Fix bug in the matching of possessive quantifiers (GH-106515) (#107796)

Browse source 
[3.12] gh-106052: Fix bug in the matching of possessive quantifiers (gh-106515)

It did not work in the case of a subpattern containing backtracking.

Temporary implement possessive quantifiers as equivalent greedy qualifiers
in atomic groups..
(cherry picked from commit 7b6e34e5ba)
This commit is contained in:
Serhiy Storchaka 2023-08-09 13:26:51 +03:00 • committed by GitHub
parent aa2ecef22a
commit 3bb43b7b1b
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 21 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

7
Lib/re/_compiler.py
View file

@ -100,6 +100,13 @@ def _compile(code, pattern, flags):
emit(ANY_ALL)
else:
emit(ANY)
elif op is POSSESSIVE_REPEAT:
# gh-106052: Possessive quantifiers do not work when the
# subpattern contains backtracking, i.e. "(?:ab?c)*+".
# Implement it as equivalent greedy qualifier in atomic group.
p = [(MAX_REPEAT, av)]
p = [(ATOMIC_GROUP, p)]
_compile(code, p, flags)
elif op in REPEATING_CODES:
if flags & SRE_FLAG_TEMPLATE:
raise error("internal: unsupported template operator %r" % (op,))