The following bug has been logged on the website:
Bug reference: 11478
Logged by: Christoph Berg
Email address: myon@debian.org
PostgreSQL version: 9.2.9
Operating system: any
Description:
The following was reported in
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=760564 :
select regexp_matches('foo/bar/baz',
'^([^/]+?)(?:/([^/]+?))(?:/([^/]+?))?$', '');
Correct 9.1 result:
regexp_matches
----------------
{foo,bar,baz}
Bad 9.2 and later result:
regexp_matches
----------------
(0 rows)
Removing the last or second-last ? brings the match back.
Perl also thinks the regexp should match:
$ perl -wle 'print "$1 $2 $3" if "foo/bar/baz" =~
m!^([^/]+?)(?:/([^/]+?))(?:/([^/]+?))?$!'
foo bar baz
(There should probably be much less ? in the regexp in the first place, but
a regression/bug is a bug.)