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classification
Title: re.sub: two-digit group-reference hangs
Type: Stage:
Components: Regular Expressions Versions: Python 2.3
process
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: niemeyer Nosy List: effbot, jmdyck, niemeyer
Priority: normal Keywords:

Created on 2004-08-30 01:36 by jmdyck, last changed 2022-04-11 14:56 by admin. This issue is now closed.

Files
File name Uploaded Description Edit
diff jmdyck, 2004-08-30 01:36 diff -C 2 sre_parse.py.ORIG sre_parse.py
Messages (5)
msg22270 - (view) Author: Michael Dyck (jmdyck) Date: 2004-08-30 01:36
Python 2.3.3 (#2, Feb 17 2004, 11:45:40)
[GCC 3.3.2 (Mandrake Linux 10.0 3.3.2-6mdk)] on linux2

I think this affects 2.4 as well.

If you invoke re.sub(), and the replacement contains a
two-digit group-reference, it hangs. E.g. try

print re.sub( r'(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)', 
r'\10', 'abcdefghijklm' )

Problem is infinite loop in sre_parse.py.

I've attached a change that I think fixes it.
msg22271 - (view) Author: Michael Dyck (jmdyck) Date: 2004-08-30 01:45
Logged In: YES 
user_id=663727

It sounds like this bug was fixed by patch 1018386 just
yesterday!

(Please check.)
msg22272 - (view) Author: Fredrik Lundh (effbot) * (Python committer) Date: 2004-09-03 11:38
Logged In: YES 
user_id=38376

Still there in 2.4a3, it seems.
msg22273 - (view) Author: Fredrik Lundh (effbot) * (Python committer) Date: 2004-09-03 11:44
Logged In: YES 
user_id=38376

Assigning to Gustavo, who's reviewing #1018386 at the 
moment.
msg22274 - (view) Author: Gustavo Niemeyer (niemeyer) * (Python committer) Date: 2004-09-03 17:26
Logged In: YES 
user_id=7887

Patch #1018386 was applied, and really fixes this bug. 
 
Thanks folks! 
History
Date User Action Args
2022-04-11 14:56:06adminsetgithub: 40843
2004-08-30 01:36:00jmdyckcreate