[Mediawiki-l] PHP 5.2.x and ini_set( 'pcre.backtrack_limit', '2M' ); in LocalSettings.php

[roger at rogerchrisman.com]

I added the following regarding 'pcre.backtrack_limit' and PHP 5.2.x
to the MediaWiki.org wiki at
http://www.mediawiki.org/wiki/Manual:$wgSpamRegex :

    ===pcre.backtrack_limit===

    PHP 5.2.x introduced pcre.backtrack_limit with default 100000
(less than 100K). I think that is too low and trips up the regex. See
stronk7 at moodle dot org's 13-Sep-2007 comment (Find '13-Sep-2007')
at http://us.php.net/manual/en/ref.pcre.php. Try adding the following
line to LocalSettings.php:

    ini_set( 'pcre.backtrack_limit', '2M' );

    I don't know what value is appropriate. 2M works for me. Someone
who knows more please adjust that.


Is 2M reasonable there? What about 8M?

What would be a safe setting? What other server configs dictate what
is appropriate there?

And I set 'memory_limit' to 20M in my LocalSettings.php. Is that
necessary? Is this appropriate, too?

     ini_set( 'memory_limit', '20M' );

What sort of trouble am I getting into?


Thanks,

Roger --Wikigogy.org
MediaWiki 	1.16.0
PHP 	5.2.14 (litespeed)
MySQL 	5.0.91-community-log