Re: [Phpwiki-talk] PCRE Crash in virgin setup (pgsrc files)

[Reini U. <ru...@x-...>]

Dan Kamins schrieb:
> On Sun, 22 Aug 2004 14:24:43 +0200, Reini Urban wrote:
>>Dan Kamins schrieb:
>>
>>>I'm kind of at a standstill now though, because 1.2 doesn't have
>>>the features I need (as mentioned below) or work on my server
>>>without modifications, and 1.3 crashes my server in a weird way (
>>>http://sourceforge.net/tracker/?func=detail&aid=1013350&group_id=6121&
>>>atid=106121 )... What to do... Anybody seen this PCRE crash
>>>before?
>>>
>>>>From the bug report, this code crashes (which is a simpler
>>>>version of what my ConvertOldMarkup() does to the file
>>>>OldTextFormattingRules during virgin setup):
>>>
>>>$pat = "/\A((?:.|\n)*?)(^(?:[ \t]+\S(?:.*\s*\n[ \t]+\S)*|".
>>>"\|(?:.*\n\|)*|[#*;]*(?:[*#]|;.*?:)|\[\s*(\d+)\s*\]|".
>>>"<\?plugin(?:-form)?\b.*\?>\s*$|!{1,3}[^!]).*$)\n?/m"; $subj =
>>>str_repeat("123456789 ", 50); preg_match($pat, $subj);
>>
>>yes, this is a known issue.
>>cause still unknown. happens only with huge anchored regex.
>>
>>please remove pgsrc/OldTextFormattingRules on virgin setup.
>>
> 
> 
> Well I removed that file and got the crash on another file instead.
I'm sure if I remove THAT file, then it will crash on either another one
of the pgsrc files or one of my users' pages. Basically it's not
useable, and I can't really grok that regexp enough to do anything about
it (like splitting it up into multiple passes with smaller expressions
or something...).

There are two other oldmarkup files known to crash, yes.

> Guys, the app looks great, and I hope you keep up the good work. If
you could post (reply to this) to this mailing list when you fix this
particular bug, I'm sure I (and whoever else finds this thread) will be
excited to get back on the bandwagon. If there's anything I can do to
help for now, let me know. Otherwise I'll be waiting on the sidelines
and watching this list.

If the ConvertOldMarkup() bug will be fixed, the new release will be 
announced. The other issue (large pagelist sets) has a long history on 
sf.net, and only affects huge wikidb's with complied in memory-limit. 
And can easily be worked around with a default limit in AllPages (aka 
"Paging").

lib/upgrade.php and lib/install.php (autoinstaller) need some minor 
tweaks also.
-- 
Reini Urban
http://xarch.tu-graz.ac.at/home/rurban/