Fix issue 618 by returning the input unaltered in case PCRE still fails

to evaluate it with the expanded backtrack limit.
This commit is contained in:
Thomas Keller 2011-03-18 12:10:42 +01:00
parent 5f008a14f5
commit 734ddda363
3 changed files with 77 additions and 38 deletions

51
src/IDF/Template.php Normal file
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@ -0,0 +1,51 @@
<?php
/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
# ***** BEGIN LICENSE BLOCK *****
# This file is part of InDefero, an open source project management application.
# Copyright (C) 2011 Céondo Ltd and contributors.
#
# InDefero is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# InDefero is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#
# ***** END LICENSE BLOCK ***** */
/**
* PHP sets the backtrack limit quite low, so some (harder to analyze) regexes may fail
* unexpectedly on large inputs or weird cornercases (see issue 618). Unfortunately this
* fix does not always work and the execution time gets bigger the bigger we set the limit,
* so in case PCRE fails to analyze the input string and preg_replace(_callback) returns NULL,
* we at least return the input string unaltered.
*
* @param $pattern The pattern
* @param $mixed Callback or replacement string
* @param $input The input
* @return The output
*/
function IDF_Template_safePregReplace($pattern, $mixed, $input)
{
$pcre_backtrack_limit = ini_get('pcre.backtrack_limit');
ini_set('pcre.backtrack_limit', 10000000);
if (is_string($mixed) && !function_exists($mixed))
$output = preg_replace($pattern, $mixed, $input);
else
$output = preg_replace_callback($pattern, $mixed, $input);
if ($output === null)
$output = $input;
ini_set('pcre.backtrack_limit', $pcre_backtrack_limit);
return $output;
}

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@ -22,6 +22,7 @@
# ***** END LICENSE BLOCK ***** */ # ***** END LICENSE BLOCK ***** */
Pluf::loadFunction('Pluf_HTTP_URL_urlForView'); Pluf::loadFunction('Pluf_HTTP_URL_urlForView');
Pluf::loadFunction('IDF_Template_safePregReplace');
/** /**
* Make the links to issues and commits. * Make the links to issues and commits.
@ -34,36 +35,31 @@ class IDF_Template_IssueComment extends Pluf_Template_Tag
function start($text, $request, $echo=true, $wordwrap=true, $esc=true, $autolink=true, $nl2br=false) function start($text, $request, $echo=true, $wordwrap=true, $esc=true, $autolink=true, $nl2br=false)
{ {
// PHP sets the backtrack limit quite low, so some regexes may
// fail unexpectedly on large inputs or weird cornercases (see issue 618)
$pcre_backtrack_limit = ini_get('pcre.backtrack_limit');
ini_set('pcre.backtrack_limit', 10000000);
$this->project = $request->project; $this->project = $request->project;
$this->request = $request; $this->request = $request;
$this->scm = IDF_Scm::get($request->project); $this->scm = IDF_Scm::get($request->project);
if ($esc) $text = Pluf_esc($text); if ($esc) $text = Pluf_esc($text);
if ($autolink) { if ($autolink) {
$text = preg_replace('#([a-z]+://[^\s\(\)]+)#i', $text = IDF_Template_safePregReplace('#([a-z]+://[^\s\(\)]+)#i',
'<a href="\1">\1</a>', $text); '<a href="\1">\1</a>', $text);
} }
if ($request->rights['hasIssuesAccess']) { if ($request->rights['hasIssuesAccess']) {
$text = preg_replace_callback('#((?:issue|bug|ticket)(s)?\s+|\s+\#)(\d+)(\#ic\d+)?(?(2)((?:[, \w]+(?:\s+\#)?)?\d+(?:\#ic\d+)?){0,})#im', $text = IDF_Template_safePregReplace('#((?:issue|bug|ticket)(s)?\s+|\s+\#)(\d+)(\#ic\d+)?(?(2)((?:[, \w]+(?:\s+\#)?)?\d+(?:\#ic\d+)?){0,})#im',
array($this, 'callbackIssues'), $text); array($this, 'callbackIssues'), $text);
} }
if ($request->rights['hasReviewAccess']) { if ($request->rights['hasReviewAccess']) {
$text = preg_replace_callback('#(reviews?\s+)(\d+(?:(?:\s+and|\s+or|,)\s+\d+)*)\b#i', $text = IDF_Template_safePregReplace('#(reviews?\s+)(\d+(?:(?:\s+and|\s+or|,)\s+\d+)*)\b#i',
array($this, 'callbackReviews'), $text); array($this, 'callbackReviews'), $text);
} }
if ($request->rights['hasSourceAccess']) { if ($request->rights['hasSourceAccess']) {
$verbs = array('added', 'fixed', 'reverted', 'changed', 'removed'); $verbs = array('added', 'fixed', 'reverted', 'changed', 'removed');
$nouns = array('commit', 'commits', 'revision', 'revisions', 'rev', 'revs'); $nouns = array('commit', 'commits', 'revision', 'revisions', 'rev', 'revs');
$prefix = implode(' in|', $verbs).' in' . '|'. $prefix = implode(' in|', $verbs).' in' . '|'.
implode('|', $nouns); implode('|', $nouns);
$text = preg_replace_callback('#((?:'.$prefix.')(?:\s+r?))([0-9a-f]{1,40}((?:\s+and|\s+or|,)\s+r?[0-9a-f]{1,40})*)\b#i', $text = IDF_Template_safePregReplace('#((?:'.$prefix.')(?:\s+r?))([0-9a-f]{1,40}((?:\s+and|\s+or|,)\s+r?[0-9a-f]{1,40})*)\b#i',
array($this, 'callbackCommits'), $text); array($this, 'callbackCommits'), $text);
$text = preg_replace_callback('=(src:)([^\s@#,\(\)\\\\]+(?:(\\\\)[\s@#][^\s@#,\(\)\\\\]+){0,})+(?:\@([^\s#,]+))(?:#(\d+))?=im', $text = IDF_Template_safePregReplace('=(src:)([^\s@#,\(\)\\\\]+(?:(\\\\)[\s@#][^\s@#,\(\)\\\\]+){0,})+(?:\@([^\s#,]+))(?:#(\d+))?=im',
array($this, 'callbackSource'), $text); array($this, 'callbackSource'), $text);
} }
if ($wordwrap) $text = Pluf_Text::wrapHtml($text, 69, "\n"); if ($wordwrap) $text = Pluf_Text::wrapHtml($text, 69, "\n");
if ($nl2br) $text = nl2br($text); if ($nl2br) $text = nl2br($text);
@ -72,8 +68,6 @@ class IDF_Template_IssueComment extends Pluf_Template_Tag
} else { } else {
return $text; return $text;
} }
ini_set('pcre.backtrack_limit', $pcre_backtrack_limit);
} }
/** /**
@ -101,9 +95,9 @@ class IDF_Template_IssueComment extends Pluf_Template_Tag
} }
return $m[0]; // not existing issue. return $m[0]; // not existing issue.
} }
return preg_replace_callback('#(\#)?(\d+)(\#ic\d+)?#', return IDF_Template_safePregReplace('#(\#)?(\d+)(\#ic\d+)?#',
array($this, 'callbackIssue'), array($this, 'callbackIssue'),
$m[0]); $m[0]);
} }
/** /**
@ -138,7 +132,7 @@ class IDF_Template_IssueComment extends Pluf_Template_Tag
return $m[1].call_user_func(array($this, 'callbackCommit'), array($m[2])); return $m[1].call_user_func(array($this, 'callbackCommit'), array($m[2]));
} }
// Multiple commits like 'commits 6e030e6, a25bfc1 and 3c094f8'. // Multiple commits like 'commits 6e030e6, a25bfc1 and 3c094f8'.
return $m[1].preg_replace_callback('#\b[0-9a-f]{1,40}\b#i', array($this, 'callbackCommit'), $m[2]); return $m[1].IDF_Template_safePregReplace('#\b[0-9a-f]{1,40}\b#i', array($this, 'callbackCommit'), $m[2]);
} }
/** /**
@ -170,7 +164,7 @@ class IDF_Template_IssueComment extends Pluf_Template_Tag
{ {
$keyword = rtrim($m[1]); $keyword = rtrim($m[1]);
if ('reviews' === $keyword) { if ('reviews' === $keyword) {
return $m[1].preg_replace_callback('#\b(\d+)\b#i', array($this, 'callbackReview'), $m[2]); return $m[1].IDF_Template_safePregReplace('#\b(\d+)\b#i', array($this, 'callbackReview'), $m[2]);
} else if ('review' === $keyword) { } else if ('review' === $keyword) {
return $m[1].call_user_func(array($this, 'callbackReview'), array('', $m[2])); return $m[1].call_user_func(array($this, 'callbackReview'), array('', $m[2]));
} }

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@ -22,6 +22,7 @@
# ***** END LICENSE BLOCK ***** */ # ***** END LICENSE BLOCK ***** */
Pluf::loadFunction('Pluf_Text_MarkDown_parse'); Pluf::loadFunction('Pluf_Text_MarkDown_parse');
Pluf::loadFunction('IDF_Template_safePregReplace');
/** /**
* Make the links to issues and commits. * Make the links to issues and commits.
@ -34,11 +35,6 @@ class IDF_Template_Markdown extends Pluf_Template_Tag
function start($text, $request) function start($text, $request)
{ {
// PHP sets the backtrack limit quite low, so some regexes may
// fail unexpectedly on large inputs or weird cornercases (see issue 618)
$pcre_backtrack_limit = ini_get('pcre.backtrack_limit');
ini_set('pcre.backtrack_limit', 10000000);
$this->project = $request->project; $this->project = $request->project;
$this->request = $request; $this->request = $request;
// Replace like in the issue text // Replace like in the issue text
@ -47,22 +43,20 @@ class IDF_Template_Markdown extends Pluf_Template_Tag
// Replace [[[path/to/file.mdtext, commit]]] with embedding // Replace [[[path/to/file.mdtext, commit]]] with embedding
// the content of the file into the wki page // the content of the file into the wki page
if ($this->request->rights['hasSourceAccess']) { if ($this->request->rights['hasSourceAccess']) {
$text = preg_replace_callback('#\[\[\[([^\,]+)(?:, ([^/]+))?\]\]\]#im', $text = IDF_Template_safePregReplace('#\[\[\[([^\,]+)(?:, ([^/]+))?\]\]\]#im',
array($this, 'callbackEmbeddedDoc'), array($this, 'callbackEmbeddedDoc'),
$text); $text);
} }
// Replace [Page]([[PageName]]) with corresponding link to the page, with link text being Page. // Replace [Page]([[PageName]]) with corresponding link to the page, with link text being Page.
$text = preg_replace_callback('#\[([^\]]+)\]\(\[\[([A-Za-z0-9\-]+)\]\]\)#im', $text = IDF_Template_safePregReplace('#\[([^\]]+)\]\(\[\[([A-Za-z0-9\-]+)\]\]\)#im',
array($this, 'callbackWikiPage'), array($this, 'callbackWikiPage'),
$text); $text);
// Replace [[PageName]] with corresponding link to the page. // Replace [[PageName]] with corresponding link to the page.
$text = preg_replace_callback('#\[\[([A-Za-z0-9\-]+)\]\]#im', $text = IDF_Template_safePregReplace('#\[\[([A-Za-z0-9\-]+)\]\]#im',
array($this, 'callbackWikiPageNoName'), array($this, 'callbackWikiPageNoName'),
$text); $text);
$filter = new IDF_Template_MarkdownPrefilter(); $filter = new IDF_Template_MarkdownPrefilter();
echo $filter->go(Pluf_Text_MarkDown_parse($text)); echo $filter->go(Pluf_Text_MarkDown_parse($text));
ini_set('pcre.backtrack_limit', $pcre_backtrack_limit);
} }
function callbackWikiPageNoName($m) function callbackWikiPageNoName($m)