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Issues (847)

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Cross-Site Scripting
Cross-Site Scripting enables an attacker to inject code into the response of a web-request that is viewed by other users. It can for example be used to bypass access controls, or even to take over other users' accounts.
File Exposure
File Exposure allows an attacker to gain access to local files that he should not be able to access. These files can for example include database credentials, or other configuration files.
File Manipulation
File Manipulation enables an attacker to write custom data to files. This potentially leads to injection of arbitrary code on the server.
Object Injection
Object Injection enables an attacker to inject an object into PHP code, and can lead to arbitrary code execution, file exposure, or file manipulation attacks.
Code Injection
Code Injection enables an attacker to execute arbitrary code on the server.
Response Splitting
Response Splitting can be used to send arbitrary responses.
File Inclusion
File Inclusion enables an attacker to inject custom files into PHP's file loading mechanism, either explicitly passed to include, or for example via PHP's auto-loading mechanism.
Command Injection
Command Injection enables an attacker to inject a shell command that is execute with the privileges of the web-server. This can be used to expose sensitive data, or gain access of your server.
SQL Injection
SQL Injection enables an attacker to execute arbitrary SQL code on your database server gaining access to user data, or manipulating user data.
XPath Injection
XPath Injection enables an attacker to modify the parts of XML document that are read. If that XML document is for example used for authentication, this can lead to further vulnerabilities similar to SQL Injection.
LDAP Injection
LDAP Injection enables an attacker to inject LDAP statements potentially granting permission to run unauthorized queries, or modify content inside the LDAP tree.
Header Injection
Other Vulnerability
This category comprises other attack vectors such as manipulating the PHP runtime, loading custom extensions, freezing the runtime, or similar.
Regex Injection
Regex Injection enables an attacker to execute arbitrary code in your PHP process.
XML Injection
XML Injection enables an attacker to read files on your local filesystem including configuration files, or can be abused to freeze your web-server process.
Variable Injection
Variable Injection enables an attacker to overwrite program variables with custom data, and can lead to further vulnerabilities.
Unfortunately, the security analysis is currently not available for your project. If you are a non-commercial open-source project, please contact support to gain access.
inc/DifferenceEngine.php (6 issues)

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<?php
/**
 * A PHP diff engine for phpwiki. (Taken from phpwiki-1.3.3)
 *
 * Additions by Axel Boldt for MediaWiki
 *
 * @copyright (C) 2000, 2001 Geoffrey T. Dairiki <[email protected]>
 * @license  You may copy this code freely under the conditions of the GPL.
 */
define('USE_ASSERTS', function_exists('assert'));

class _DiffOp {
    var $type;
    var $orig;
    var $closing;

    /**
     * @return _DiffOp
     */
    function reverse() {
        trigger_error("pure virtual", E_USER_ERROR);
    }

    function norig() {
        return $this->orig ? count($this->orig) : 0;
    }

    function nclosing() {
        return $this->closing ? count($this->closing) : 0;
    }
}

class _DiffOp_Copy extends _DiffOp {
    var $type = 'copy';

    function __construct($orig, $closing = false) {
        if (!is_array($closing))
            $closing = $orig;
        $this->orig = $orig;
        $this->closing = $closing;
    }

    function reverse() {
        return new _DiffOp_Copy($this->closing, $this->orig);
    }
}

class _DiffOp_Delete extends _DiffOp {
    var $type = 'delete';

    function __construct($lines) {
        $this->orig = $lines;
        $this->closing = false;
    }

    function reverse() {
        return new _DiffOp_Add($this->orig);
    }
}

class _DiffOp_Add extends _DiffOp {
    var $type = 'add';

    function __construct($lines) {
        $this->closing = $lines;
        $this->orig = false;
    }

    function reverse() {
        return new _DiffOp_Delete($this->closing);
    }
}

class _DiffOp_Change extends _DiffOp {
    var $type = 'change';

    function __construct($orig, $closing) {
        $this->orig = $orig;
        $this->closing = $closing;
    }

    function reverse() {
        return new _DiffOp_Change($this->closing, $this->orig);
    }
}


/**
 * Class used internally by Diff to actually compute the diffs.
 *
 * The algorithm used here is mostly lifted from the perl module
 * Algorithm::Diff (version 1.06) by Ned Konz, which is available at:
 *   http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip
 *
 * More ideas are taken from:
 *   http://www.ics.uci.edu/~eppstein/161/960229.html
 *
 * Some ideas are (and a bit of code) are from from analyze.c, from GNU
 * diffutils-2.7, which can be found at:
 *   ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz
 *
 * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations)
 * are my own.
 *
 * @author Geoffrey T. Dairiki
 * @access private
 */
class _DiffEngine {

    var $xchanged = array();
    var $ychanged = array();
    var $xv = array();
    var $yv = array();
    var $xind = array();
    var $yind = array();
    var $seq;
    var $in_seq;
    var $lcs;

    /**
     * @param array $from_lines
     * @param array $to_lines
     * @return _DiffOp[]
     */
    function diff($from_lines, $to_lines) {
        $n_from = count($from_lines);
        $n_to = count($to_lines);

        $this->xchanged = $this->ychanged = array();
        $this->xv = $this->yv = array();
        $this->xind = $this->yind = array();
        unset($this->seq);
        unset($this->in_seq);
        unset($this->lcs);

        // Skip leading common lines.
        for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) {
            if ($from_lines[$skip] != $to_lines[$skip])
                break;
            $this->xchanged[$skip] = $this->ychanged[$skip] = false;
        }
        // Skip trailing common lines.
        $xi = $n_from;
        $yi = $n_to;
        for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) {
            if ($from_lines[$xi] != $to_lines[$yi])
                break;
            $this->xchanged[$xi] = $this->ychanged[$yi] = false;
        }

        // Ignore lines which do not exist in both files.
        for ($xi = $skip; $xi < $n_from - $endskip; $xi++)
            $xhash[$from_lines[$xi]] = 1;
foreach ($collection as $item) {
    $myArray['foo'] = $item->getFoo();

    if ($item->hasBar()) {
        $myArray['bar'] = $item->getBar();
    }

    // do something with $myArray
}
        for ($yi = $skip; $yi < $n_to - $endskip; $yi++) {
            $line = $to_lines[$yi];
            if (($this->ychanged[$yi] = empty($xhash[$line])))
                continue;
            $yhash[$line] = 1;
foreach ($collection as $item) {
    $myArray['foo'] = $item->getFoo();

    if ($item->hasBar()) {
        $myArray['bar'] = $item->getBar();
    }

    // do something with $myArray
}
            $this->yv[] = $line;
            $this->yind[] = $yi;
        }
        for ($xi = $skip; $xi < $n_from - $endskip; $xi++) {
            $line = $from_lines[$xi];
            if (($this->xchanged[$xi] = empty($yhash[$line])))
                continue;
            $this->xv[] = $line;
            $this->xind[] = $xi;
        }

        // Find the LCS.
        $this->_compareseq(0, count($this->xv), 0, count($this->yv));

        // Merge edits when possible
        $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged);
        $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged);

        // Compute the edit operations.
        $edits = array();
        $xi = $yi = 0;
        while ($xi < $n_from || $yi < $n_to) {
            USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]);
            USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]);

            // Skip matching "snake".
            $copy = array();
            while ($xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) {
                $copy[] = $from_lines[$xi++];
                ++$yi;
            }
            if ($copy)
                $edits[] = new _DiffOp_Copy($copy);

            // Find deletes & adds.
            $delete = array();
            while ($xi < $n_from && $this->xchanged[$xi])
                $delete[] = $from_lines[$xi++];

            $add = array();
            while ($yi < $n_to && $this->ychanged[$yi])
                $add[] = $to_lines[$yi++];

            if ($delete && $add)
                $edits[] = new _DiffOp_Change($delete, $add);
            elseif ($delete)
                $edits[] = new _DiffOp_Delete($delete);
            elseif ($add)
                $edits[] = new _DiffOp_Add($add);
        }
        return $edits;
    }


    /**
     * Divide the Largest Common Subsequence (LCS) of the sequences
     * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally
     * sized segments.
     *
     * Returns (LCS, PTS).  LCS is the length of the LCS. PTS is an
     * array of NCHUNKS+1 (X, Y) indexes giving the diving points between
     * sub sequences.  The first sub-sequence is contained in [X0, X1),
     * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on.  Note
     * that (X0, Y0) == (XOFF, YOFF) and
     * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM).
     *
     * This function assumes that the first lines of the specified portions
     * of the two files do not match, and likewise that the last lines do not
     * match.  The caller must trim matching lines from the beginning and end
     * of the portions it is going to specify.
     *
     * @param integer $xoff
     * @param integer $xlim
     * @param integer $yoff
     * @param integer $ylim
     * @param integer $nchunks
     *
     * @return array
     */
    function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) {
        $flip = false;

        if ($xlim - $xoff > $ylim - $yoff) {
            // Things seems faster (I'm not sure I understand why)
            // when the shortest sequence in X.
            $flip = true;
            list ($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim);
        }

        if ($flip)
            for ($i = $ylim - 1; $i >= $yoff; $i--)
                $ymatches[$this->xv[$i]][] = $i;
foreach ($collection as $item) {
    $myArray['foo'] = $item->getFoo();

    if ($item->hasBar()) {
        $myArray['bar'] = $item->getBar();
    }

    // do something with $myArray
}
        else
            for ($i = $ylim - 1; $i >= $yoff; $i--)
                $ymatches[$this->yv[$i]][] = $i;
foreach ($collection as $item) {
    $myArray['foo'] = $item->getFoo();

    if ($item->hasBar()) {
        $myArray['bar'] = $item->getBar();
    }

    // do something with $myArray
}

        $this->lcs = 0;
        $this->seq[0]= $yoff - 1;
        $this->in_seq = array();
        $ymids[0] = array();
foreach ($collection as $item) {
    $myArray['foo'] = $item->getFoo();

    if ($item->hasBar()) {
        $myArray['bar'] = $item->getBar();
    }

    // do something with $myArray
}

        $numer = $xlim - $xoff + $nchunks - 1;
        $x = $xoff;
        for ($chunk = 0; $chunk < $nchunks; $chunk++) {
            if ($chunk > 0)
                for ($i = 0; $i <= $this->lcs; $i++)
                    $ymids[$i][$chunk-1] = $this->seq[$i];

            $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks);
            for ( ; $x < $x1; $x++) {
                $line = $flip ? $this->yv[$x] : $this->xv[$x];
                if (empty($ymatches[$line]))
                    continue;
                $matches = $ymatches[$line];
                $switch = false;
                foreach ($matches as $y) {
                    if ($switch && $y > $this->seq[$k-1]) {
                        USE_ASSERTS && assert($y < $this->seq[$k]);
                        // Optimization: this is a common case:
                        //  next match is just replacing previous match.
                        $this->in_seq[$this->seq[$k]] = false;
                        $this->seq[$k] = $y;
                        $this->in_seq[$y] = 1;
                    }
                    else if (empty($this->in_seq[$y])) {
                        $k = $this->_lcs_pos($y);
                        USE_ASSERTS && assert($k > 0);
                        $ymids[$k] = $ymids[$k-1];
                        $switch = true;
                    }
                }
            }
        }

        $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff);
foreach ($collection as $item) {
    $myArray['foo'] = $item->getFoo();

    if ($item->hasBar()) {
        $myArray['bar'] = $item->getBar();
    }

    // do something with $myArray
}
        $ymid = $ymids[$this->lcs];
        for ($n = 0; $n < $nchunks - 1; $n++) {
            $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks);
            $y1 = $ymid[$n] + 1;
            $seps[] = $flip ? array($y1, $x1) : array($x1, $y1);
        }
        $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim);

        return array($this->lcs, $seps);
    }

    function _lcs_pos($ypos) {
        $end = $this->lcs;
        if ($end == 0 || $ypos > $this->seq[$end]) {
            $this->seq[++$this->lcs] = $ypos;
            $this->in_seq[$ypos] = 1;
            return $this->lcs;
        }

        $beg = 1;
        while ($beg < $end) {
            $mid = (int)(($beg + $end) / 2);
            if ($ypos > $this->seq[$mid])
                $beg = $mid + 1;
            else
                $end = $mid;
        }

        USE_ASSERTS && assert($ypos != $this->seq[$end]);

        $this->in_seq[$this->seq[$end]] = false;
        $this->seq[$end] = $ypos;
        $this->in_seq[$ypos] = 1;
        return $end;
    }

    /**
     * Find LCS of two sequences.
     *
     * The results are recorded in the vectors $this->{x,y}changed[], by
     * storing a 1 in the element for each line that is an insertion
     * or deletion (ie. is not in the LCS).
     *
     * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1.
     *
     * Note that XLIM, YLIM are exclusive bounds.
     * All line numbers are origin-0 and discarded lines are not counted.
     *
     * @param integer $xoff
     * @param integer $xlim
     * @param integer $yoff
     * @param integer $ylim
     */
    function _compareseq($xoff, $xlim, $yoff, $ylim) {
        // Slide down the bottom initial diagonal.
        while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) {
            ++$xoff;
            ++$yoff;
        }

        // Slide up the top initial diagonal.
        while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) {
            --$xlim;
            --$ylim;
        }

        if ($xoff == $xlim || $yoff == $ylim)
            $lcs = 0;
        else {
            // This is ad hoc but seems to work well.
            //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5);
            //$nchunks = max(2,min(8,(int)$nchunks));
            $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1;
            list ($lcs, $seps)
                = $this->_diag($xoff,$xlim,$yoff, $ylim,$nchunks);
        }

        if ($lcs == 0) {
            // X and Y sequences have no common subsequence:
            // mark all changed.
            while ($yoff < $ylim)
                $this->ychanged[$this->yind[$yoff++]] = 1;
            while ($xoff < $xlim)
                $this->xchanged[$this->xind[$xoff++]] = 1;
        }
        else {
            // Use the partitions to split this problem into subproblems.
            reset($seps);
            $pt1 = $seps[0];
            while ($pt2 = next($seps)) {
                $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]);
                $pt1 = $pt2;
            }
        }
    }

    /**
     * Adjust inserts/deletes of identical lines to join changes
     * as much as possible.
     *
     * We do something when a run of changed lines include a
     * line at one end and has an excluded, identical line at the other.
     * We are free to choose which identical line is included.
     * `compareseq' usually chooses the one at the beginning,
     * but usually it is cleaner to consider the following identical line
     * to be the "change".
     *
     * This is extracted verbatim from analyze.c (GNU diffutils-2.7).
     *
     * @param array $lines
     * @param array $changed
     * @param array $other_changed
     */
    function _shift_boundaries($lines, &$changed, $other_changed) {
        $i = 0;
        $j = 0;

        USE_ASSERTS && assert(count($lines) == count($changed));
        $len = count($lines);
        $other_len = count($other_changed);

        while (1) {
            /*
             * Scan forwards to find beginning of another run of changes.
             * Also keep track of the corresponding point in the other file.
             *
             * Throughout this code, $i and $j are adjusted together so that
             * the first $i elements of $changed and the first $j elements
             * of $other_changed both contain the same number of zeros
             * (unchanged lines).
             * Furthermore, $j is always kept so that $j == $other_len or
             * $other_changed[$j] == false.
             */
            while ($j < $other_len && $other_changed[$j])
                $j++;

            while ($i < $len && ! $changed[$i]) {
                USE_ASSERTS && assert($j < $other_len && ! $other_changed[$j]);
                $i++;
                $j++;
                while ($j < $other_len && $other_changed[$j])
                    $j++;
            }

            if ($i == $len)
                break;

            $start = $i;

            // Find the end of this run of changes.
            while (++$i < $len && $changed[$i])
                continue;

            do {
                /*
                 * Record the length of this run of changes, so that
                 * we can later determine whether the run has grown.
                 */
                $runlength = $i - $start;

                /*
                 * Move the changed region back, so long as the
                 * previous unchanged line matches the last changed one.
                 * This merges with previous changed regions.
                 */
                while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) {
                    $changed[--$start] = 1;
                    $changed[--$i] = false;
                    while ($start > 0 && $changed[$start - 1])
                        $start--;
                    USE_ASSERTS && assert($j > 0);
                    while ($other_changed[--$j])
                        continue;
                    USE_ASSERTS && assert($j >= 0 && !$other_changed[$j]);
                }

                /*
                 * Set CORRESPONDING to the end of the changed run, at the last
                 * point where it corresponds to a changed run in the other file.
                 * CORRESPONDING == LEN means no such point has been found.
                 */
                $corresponding = $j < $other_len ? $i : $len;

                /*
                 * Move the changed region forward, so long as the
                 * first changed line matches the following unchanged one.
                 * This merges with following changed regions.
                 * Do this second, so that if there are no merges,
                 * the changed region is moved forward as far as possible.
                 */
                while ($i < $len && $lines[$start] == $lines[$i]) {
                    $changed[$start++] = false;
                    $changed[$i++] = 1;
                    while ($i < $len && $changed[$i])
                        $i++;

                    USE_ASSERTS && assert($j < $other_len && ! $other_changed[$j]);
                    $j++;
                    if ($j < $other_len && $other_changed[$j]) {
                        $corresponding = $i;
                        while ($j < $other_len && $other_changed[$j])
                            $j++;
                    }
                }
            } while ($runlength != $i - $start);

            /*
             * If possible, move the fully-merged run of changes
             * back to a corresponding run in the other file.
             */
            while ($corresponding < $i) {
                $changed[--$start] = 1;
                $changed[--$i] = 0;
                USE_ASSERTS && assert($j > 0);
                while ($other_changed[--$j])
                    continue;
                USE_ASSERTS && assert($j >= 0 && !$other_changed[$j]);
            }
        }
    }
}

/**
 * Class representing a 'diff' between two sequences of strings.
 */
class Diff {

    var $edits;

    /**
     * Constructor.
     * Computes diff between sequences of strings.
     *
     * @param array $from_lines An array of strings.
     *                          (Typically these are lines from a file.)
     * @param array $to_lines   An array of strings.
     */
    function __construct($from_lines, $to_lines) {
        $eng = new _DiffEngine;
        $this->edits = $eng->diff($from_lines, $to_lines);
        //$this->_check($from_lines, $to_lines);
    }

    /**
     * Compute reversed Diff.
     *
     * SYNOPSIS:
     *
     *  $diff = new Diff($lines1, $lines2);
     *  $rev = $diff->reverse();
     *
     * @return Diff  A Diff object representing the inverse of the
     *               original diff.
     */
    function reverse() {
        $rev = $this;
        $rev->edits = array();
        foreach ($this->edits as $edit) {
            $rev->edits[] = $edit->reverse();
        }
        return $rev;
    }

    /**
     * Check for empty diff.
     *
     * @return bool True iff two sequences were identical.
     */
    function isEmpty() {
        foreach ($this->edits as $edit) {
            if ($edit->type != 'copy')
                return false;
        }
        return true;
    }

    /**
     * Compute the length of the Longest Common Subsequence (LCS).
     *
     * This is mostly for diagnostic purposed.
     *
     * @return int The length of the LCS.
     */
    function lcs() {
        $lcs = 0;
        foreach ($this->edits as $edit) {
            if ($edit->type == 'copy')
                $lcs += count($edit->orig);
        }
        return $lcs;
    }

    /**
     * Get the original set of lines.
     *
     * This reconstructs the $from_lines parameter passed to the
     * constructor.
     *
     * @return array The original sequence of strings.
     */
    function orig() {
        $lines = array();

        foreach ($this->edits as $edit) {
            if ($edit->orig)
                array_splice($lines, count($lines), 0, $edit->orig);
        }
        return $lines;
    }

    /**
     * Get the closing set of lines.
     *
     * This reconstructs the $to_lines parameter passed to the
     * constructor.
     *
     * @return array The sequence of strings.
     */
    function closing() {
        $lines = array();

        foreach ($this->edits as $edit) {
            if ($edit->closing)
                array_splice($lines, count($lines), 0, $edit->closing);
        }
        return $lines;
    }

    /**
     * Check a Diff for validity.
     *
     * This is here only for debugging purposes.
     *
     * @param mixed $from_lines
     * @param mixed $to_lines
     */
    function _check($from_lines, $to_lines) {
        if (serialize($from_lines) != serialize($this->orig()))
            trigger_error("Reconstructed original doesn't match", E_USER_ERROR);
        if (serialize($to_lines) != serialize($this->closing()))
            trigger_error("Reconstructed closing doesn't match", E_USER_ERROR);

        $rev = $this->reverse();
        if (serialize($to_lines) != serialize($rev->orig()))
            trigger_error("Reversed original doesn't match", E_USER_ERROR);
        if (serialize($from_lines) != serialize($rev->closing()))
            trigger_error("Reversed closing doesn't match", E_USER_ERROR);

        $prevtype = 'none';
        foreach ($this->edits as $edit) {
            if ($prevtype == $edit->type)
                trigger_error("Edit sequence is non-optimal", E_USER_ERROR);
            $prevtype = $edit->type;
        }

        $lcs = $this->lcs();
        trigger_error("Diff okay: LCS = $lcs", E_USER_NOTICE);
    }
}

/**
 * FIXME: bad name.
 */
class MappedDiff extends Diff {
    /**
     * Constructor.
     *
     * Computes diff between sequences of strings.
     *
     * This can be used to compute things like
     * case-insensitve diffs, or diffs which ignore
     * changes in white-space.
     *
     * @param string[] $from_lines         An array of strings.
     *                                     (Typically these are lines from a file.)
     *
     * @param string[] $to_lines           An array of strings.
     *
     * @param string[] $mapped_from_lines  This array should
     *                                     have the same size number of elements as $from_lines.
     *                                     The elements in $mapped_from_lines and
     *                                     $mapped_to_lines are what is actually compared
     *                                     when computing the diff.
     *
     * @param string[] $mapped_to_lines    This array should
     *                                     have the same number of elements as $to_lines.
     */
    function __construct($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) {

        assert(count($from_lines) == count($mapped_from_lines));
        assert(count($to_lines) == count($mapped_to_lines));

        parent::__construct($mapped_from_lines, $mapped_to_lines);

        $xi = $yi = 0;
        $ecnt = count($this->edits);
        for ($i = 0; $i < $ecnt; $i++) {
            $orig = &$this->edits[$i]->orig;
            if (is_array($orig)) {
                $orig = array_slice($from_lines, $xi, count($orig));
                $xi += count($orig);
            }

            $closing = &$this->edits[$i]->closing;
            if (is_array($closing)) {
                $closing = array_slice($to_lines, $yi, count($closing));
                $yi += count($closing);
            }
        }
    }
}

/**
 * A class to format Diffs
 *
 * This class formats the diff in classic diff format.
 * It is intended that this class be customized via inheritance,
 * to obtain fancier outputs.
 */
class DiffFormatter {
    /**
     * Number of leading context "lines" to preserve.
     *
     * This should be left at zero for this class, but subclasses
     * may want to set this to other values.
     */
    var $leading_context_lines = 0;

    /**
     * Number of trailing context "lines" to preserve.
     *
     * This should be left at zero for this class, but subclasses
     * may want to set this to other values.
     */
    var $trailing_context_lines = 0;

    /**
     * Format a diff.
     *
     * @param Diff $diff A Diff object.
     * @return string The formatted output.
     */
    function format($diff) {

        $xi = $yi = 1;
        $x0 = $y0 = 0;
        $block = false;
        $context = array();

        $nlead = $this->leading_context_lines;
        $ntrail = $this->trailing_context_lines;

        $this->_start_diff();

        foreach ($diff->edits as $edit) {
            if ($edit->type == 'copy') {
                if (is_array($block)) {
                    if (count($edit->orig) <= $nlead + $ntrail) {
                        $block[] = $edit;
                    }
                    else{
                        if ($ntrail) {
                            $context = array_slice($edit->orig, 0, $ntrail);
                            $block[] = new _DiffOp_Copy($context);
                        }
                        $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block);
                        $block = false;
                    }
                }
                $context = $edit->orig;
            }
            else {
                if (! is_array($block)) {
                    $context = array_slice($context, count($context) - $nlead);
                    $x0 = $xi - count($context);
                    $y0 = $yi - count($context);
                    $block = array();
                    if ($context)
                        $block[] = new _DiffOp_Copy($context);
                }
                $block[] = $edit;
            }

            if ($edit->orig)
                $xi += count($edit->orig);
            if ($edit->closing)
                $yi += count($edit->closing);
        }

        if (is_array($block))
            $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block);

        return $this->_end_diff();
    }

    /**
     * @param int $xbeg
     * @param int $xlen
     * @param int $ybeg
     * @param int $ylen
     * @param array $edits
     */
    function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) {
        $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen));
        foreach ($edits as $edit) {
            if ($edit->type == 'copy')
                $this->_context($edit->orig);
            elseif ($edit->type == 'add')
                $this->_added($edit->closing);
            elseif ($edit->type == 'delete')
                $this->_deleted($edit->orig);
            elseif ($edit->type == 'change')
                $this->_changed($edit->orig, $edit->closing);
            else
                trigger_error("Unknown edit type", E_USER_ERROR);
        }
        $this->_end_block();
    }

    function _start_diff() {
        ob_start();
    }

    function _end_diff() {
        $val = ob_get_contents();
        ob_end_clean();
        return $val;
    }

    /**
     * @param int $xbeg
     * @param int $xlen
     * @param int $ybeg
     * @param int $ylen
     * @return string
     */
    function _block_header($xbeg, $xlen, $ybeg, $ylen) {
        if ($xlen > 1)
            $xbeg .= "," . ($xbeg + $xlen - 1);
        if ($ylen > 1)
            $ybeg .= "," . ($ybeg + $ylen - 1);

        return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg;
    }

    /**
     * @param string $header
     */
    function _start_block($header) {
        echo $header;
    }

    function _end_block() {
    }

    function _lines($lines, $prefix = ' ') {
        foreach ($lines as $line)
            echo "$prefix ".$this->_escape($line)."\n";
    }

    function _context($lines) {
        $this->_lines($lines);
    }

    function _added($lines) {
        $this->_lines($lines, ">");
    }
    function _deleted($lines) {
        $this->_lines($lines, "<");
    }

    function _changed($orig, $closing) {
        $this->_deleted($orig);
        echo "---\n";
        $this->_added($closing);
    }

    /**
     * Escape string
     *
     * Override this method within other formatters if escaping required.
     * Base class requires $str to be returned WITHOUT escaping.
     *
     * @param $str string Text string to escape
     * @return string The escaped string.
     */
    function _escape($str){
        return $str;
    }
}

/**
 * Utilityclass for styling HTML formatted diffs
 *
 * Depends on global var $DIFF_INLINESTYLES, if true some minimal predefined
 * inline styles are used. Useful for HTML mails and RSS feeds
 *
 * @author Andreas Gohr <[email protected]>
 */
class HTMLDiff {
    /**
     * Holds the style names and basic CSS
     */
    static public $styles = array(
            'diff-addedline'    => 'background-color: #ddffdd;',
            'diff-deletedline'  => 'background-color: #ffdddd;',
            'diff-context'      => 'background-color: #f5f5f5;',
            'diff-mark'         => 'color: #ff0000;',
        );

    /**
     * Return a class or style parameter
     *
     * @param string $classname
     *
     * @return string
     */
    static function css($classname){
        global $DIFF_INLINESTYLES;

        if($DIFF_INLINESTYLES){
            if(!isset(self::$styles[$classname])) return '';
            return 'style="'.self::$styles[$classname].'"';
        }else{
            return 'class="'.$classname.'"';
        }
    }
}

/**
 *  Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3
 *
 */

define('NBSP', "\xC2\xA0");     // utf-8 non-breaking space.

class _HWLDF_WordAccumulator {

    function __construct() {
        $this->_lines = array();
        $this->_line = '';
        $this->_group = '';
        $this->_tag = '';
    }

    function _flushGroup($new_tag) {
        if ($this->_group !== '') {
            if ($this->_tag == 'mark')
                $this->_line .= '<strong '.HTMLDiff::css('diff-mark').'>'.$this->_escape($this->_group).'</strong>';
            elseif ($this->_tag == 'add')
                $this->_line .= '<span '.HTMLDiff::css('diff-addedline').'>'.$this->_escape($this->_group).'</span>';
            elseif ($this->_tag == 'del')
                $this->_line .= '<span '.HTMLDiff::css('diff-deletedline').'><del>'.$this->_escape($this->_group).'</del></span>';
            else
                $this->_line .= $this->_escape($this->_group);
        }
        $this->_group = '';
        $this->_tag = $new_tag;
    }

    /**
     * @param string $new_tag
     */
    function _flushLine($new_tag) {
        $this->_flushGroup($new_tag);
        if ($this->_line != '')
            $this->_lines[] = $this->_line;
        $this->_line = '';
    }

    function addWords($words, $tag = '') {
        if ($tag != $this->_tag)
            $this->_flushGroup($tag);

        foreach ($words as $word) {
            // new-line should only come as first char of word.
            if ($word == '')
                continue;
            if ($word[0] == "\n") {
                $this->_group .= NBSP;
                $this->_flushLine($tag);
                $word = substr($word, 1);
            }
            assert(!strstr($word, "\n"));
            $this->_group .= $word;
        }
    }

    function getLines() {
        $this->_flushLine('~done');
        return $this->_lines;
    }

    function _escape($str){
        return hsc($str);
    }
}

class WordLevelDiff extends MappedDiff {

    function __construct($orig_lines, $closing_lines) {
        list ($orig_words, $orig_stripped) = $this->_split($orig_lines);
        list ($closing_words, $closing_stripped) = $this->_split($closing_lines);

        parent::__construct($orig_words, $closing_words, $orig_stripped, $closing_stripped);
    }

    function _split($lines) {
        if (!preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xsu',
             implode("\n", $lines), $m)) {
            return array(array(''), array(''));
        }
        return array($m[0], $m[1]);
    }

    function orig() {
        $orig = new _HWLDF_WordAccumulator;

        foreach ($this->edits as $edit) {
            if ($edit->type == 'copy')
                $orig->addWords($edit->orig);
            elseif ($edit->orig)
                $orig->addWords($edit->orig, 'mark');
        }
        return $orig->getLines();
    }

    function closing() {
        $closing = new _HWLDF_WordAccumulator;

        foreach ($this->edits as $edit) {
            if ($edit->type == 'copy')
                $closing->addWords($edit->closing);
            elseif ($edit->closing)
                $closing->addWords($edit->closing, 'mark');
        }
        return $closing->getLines();
    }
}

class InlineWordLevelDiff extends MappedDiff {

    function __construct($orig_lines, $closing_lines) {
        list ($orig_words, $orig_stripped) = $this->_split($orig_lines);
        list ($closing_words, $closing_stripped) = $this->_split($closing_lines);

        parent::__construct($orig_words, $closing_words, $orig_stripped, $closing_stripped);
    }

    function _split($lines) {
        if (!preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xsu',
             implode("\n", $lines), $m)) {
            return array(array(''), array(''));
        }
        return array($m[0], $m[1]);
    }

    function inline() {
        $orig = new _HWLDF_WordAccumulator;
        foreach ($this->edits as $edit) {
            if ($edit->type == 'copy')
                $orig->addWords($edit->closing);
            elseif ($edit->type == 'change'){
                $orig->addWords($edit->orig, 'del');
                $orig->addWords($edit->closing, 'add');
            } elseif ($edit->type == 'delete')
                $orig->addWords($edit->orig, 'del');
            elseif ($edit->type == 'add')
                $orig->addWords($edit->closing, 'add');
            elseif ($edit->orig)
                $orig->addWords($edit->orig, 'del');
        }
        return $orig->getLines();
    }
}

/**
 * "Unified" diff formatter.
 *
 * This class formats the diff in classic "unified diff" format.
 *
 * NOTE: output is plain text and unsafe for use in HTML without escaping.
 */
class UnifiedDiffFormatter extends DiffFormatter {

    function __construct($context_lines = 4) {
        $this->leading_context_lines = $context_lines;
        $this->trailing_context_lines = $context_lines;
    }

    function _block_header($xbeg, $xlen, $ybeg, $ylen) {
        if ($xlen != 1)
            $xbeg .= "," . $xlen;
        if ($ylen != 1)
            $ybeg .= "," . $ylen;
        return "@@ -$xbeg +$ybeg @@\n";
    }

    function _added($lines) {
        $this->_lines($lines, "+");
    }
    function _deleted($lines) {
        $this->_lines($lines, "-");
    }
    function _changed($orig, $final) {
        $this->_deleted($orig);
        $this->_added($final);
    }
}

/**
 *  Wikipedia Table style diff formatter.
 *
 */
class TableDiffFormatter extends DiffFormatter {
    var $colspan = 2;

    function __construct() {
        $this->leading_context_lines = 2;
        $this->trailing_context_lines = 2;
    }

    /**
     * @param Diff $diff
     * @return string
     */
    function format($diff) {
        // Preserve whitespaces by converting some to non-breaking spaces.
        // Do not convert all of them to allow word-wrap.
        $val = parent::format($diff);
        $val = str_replace('  ','&#160; ', $val);
        $val = preg_replace('/ (?=<)|(?<=[ >]) /', '&#160;', $val);
        return $val;
    }

    function _pre($text){
        $text = htmlspecialchars($text);
        return $text;
    }

    function _block_header($xbeg, $xlen, $ybeg, $ylen) {
        global $lang;
        $l1 = $lang['line'].' '.$xbeg;
        $l2 = $lang['line'].' '.$ybeg;
        $r = '<tr><td '.HTMLDiff::css('diff-blockheader').' colspan="'.$this->colspan.'">'.$l1.":</td>\n".
             '<td '.HTMLDiff::css('diff-blockheader').' colspan="'.$this->colspan.'">'.$l2.":</td>\n".
             "</tr>\n";
        return $r;
    }

    function _start_block($header) {
        print($header);
    }

    function _end_block() {
    }

    function _lines($lines, $prefix=' ', $color="white") {
    }

    function addedLine($line,$escaped=false) {
        if (!$escaped){
            $line = $this->_escape($line);
        }
        return '<td '.HTMLDiff::css('diff-lineheader').'>+</td>'.
               '<td '.HTMLDiff::css('diff-addedline').'>' .  $line.'</td>';
    }

    function deletedLine($line,$escaped=false) {
        if (!$escaped){
            $line = $this->_escape($line);
        }
        return '<td '.HTMLDiff::css('diff-lineheader').'>-</td>'.
               '<td '.HTMLDiff::css('diff-deletedline').'>' .  $line.'</td>';
    }

    function emptyLine() {
        return '<td colspan="'.$this->colspan.'">&#160;</td>';
    }

    function contextLine($line) {
        return '<td '.HTMLDiff::css('diff-lineheader').'>&#160;</td>'.
               '<td '.HTMLDiff::css('diff-context').'>'.$this->_escape($line).'</td>';
    }

    function _added($lines) {
        $this->_addedLines($lines,false);
    }

    function _addedLines($lines,$escaped=false){
        foreach ($lines as $line) {
            print('<tr>' . $this->emptyLine() . $this->addedLine($line,$escaped) . "</tr>\n");
        }
    }

    function _deleted($lines) {
        foreach ($lines as $line) {
            print('<tr>' . $this->deletedLine($line) . $this->emptyLine() . "</tr>\n");
        }
    }

    function _context($lines) {
        foreach ($lines as $line) {
            print('<tr>' . $this->contextLine($line) .  $this->contextLine($line) . "</tr>\n");
        }
    }

    function _changed($orig, $closing) {
        $diff = new WordLevelDiff($orig, $closing);  // this escapes the diff data
        $del = $diff->orig();
        $add = $diff->closing();

        while ($line = array_shift($del)) {
            $aline = array_shift($add);
            print('<tr>' . $this->deletedLine($line,true) . $this->addedLine($aline,true) . "</tr>\n");
        }
        $this->_addedLines($add,true); # If any leftovers
    }

    function _escape($str) {
        return hsc($str);
    }
}

/**
 *  Inline style diff formatter.
 *
 */
class InlineDiffFormatter extends DiffFormatter {
    var $colspan = 2;

    function __construct() {
        $this->leading_context_lines = 2;
        $this->trailing_context_lines = 2;
    }

    /**
     * @param Diff $diff
     * @return string
     */
    function format($diff) {
        // Preserve whitespaces by converting some to non-breaking spaces.
        // Do not convert all of them to allow word-wrap.
        $val = parent::format($diff);
        $val = str_replace('  ','&#160; ', $val);
        $val = preg_replace('/ (?=<)|(?<=[ >]) /', '&#160;', $val);
        return $val;
    }

    function _pre($text){
        $text = htmlspecialchars($text);
        return $text;
    }

    function _block_header($xbeg, $xlen, $ybeg, $ylen) {
        global $lang;
        if ($xlen != 1)
            $xbeg .= "," . $xlen;
        if ($ylen != 1)
            $ybeg .= "," . $ylen;
        $r = '<tr><td colspan="'.$this->colspan.'" '.HTMLDiff::css('diff-blockheader').'>@@ '.$lang['line']." -$xbeg +$ybeg @@";
        $r .= ' <span '.HTMLDiff::css('diff-deletedline').'><del>'.$lang['deleted'].'</del></span>';
        $r .= ' <span '.HTMLDiff::css('diff-addedline').'>'.$lang['created'].'</span>';
        $r .= "</td></tr>\n";
        return $r;
    }

    function _start_block($header) {
        print($header."\n");
    }

    function _end_block() {
    }

    function _lines($lines, $prefix=' ', $color="white") {
    }

    function _added($lines) {
        foreach ($lines as $line) {
            print('<tr><td '.HTMLDiff::css('diff-lineheader').'>&#160;</td><td '.HTMLDiff::css('diff-addedline').'>'. $this->_escape($line) . "</td></tr>\n");
        }
    }

    function _deleted($lines) {
        foreach ($lines as $line) {
            print('<tr><td '.HTMLDiff::css('diff-lineheader').'>&#160;</td><td '.HTMLDiff::css('diff-deletedline').'><del>' . $this->_escape($line) . "</del></td></tr>\n");
        }
    }

    function _context($lines) {
        foreach ($lines as $line) {
            print('<tr><td '.HTMLDiff::css('diff-lineheader').'>&#160;</td><td '.HTMLDiff::css('diff-context').'>'. $this->_escape($line) ."</td></tr>\n");
        }
    }

    function _changed($orig, $closing) {
        $diff = new InlineWordLevelDiff($orig, $closing);  // this escapes the diff data
        $add = $diff->inline();

        foreach ($add as $line)
            print('<tr><td '.HTMLDiff::css('diff-lineheader').'>&#160;</td><td>'.$line."</td></tr>\n");
    }

    function _escape($str) {
        return hsc($str);
    }
}

/**
 * A class for computing three way diffs.
 *
 * @author  Geoffrey T. Dairiki <[email protected]>
 */
class Diff3 extends Diff {

    /**
     * Conflict counter.
     *
     * @var integer
     */
    var $_conflictingBlocks = 0;

    /**
     * Computes diff between 3 sequences of strings.
     *
     * @param array $orig    The original lines to use.
     * @param array $final1  The first version to compare to.
     * @param array $final2  The second version to compare to.
     */
    function __construct($orig, $final1, $final2) {
        $engine = new _DiffEngine();

        $this->_edits = $this->_diff3($engine->diff($orig, $final1),
                                      $engine->diff($orig, $final2));
    }

    /**
     * Returns the merged lines
     *
     * @param string $label1  label for first version
     * @param string $label2  label for second version
     * @param string $label3  separator between versions
     * @return array          lines of the merged text
     */
    function mergedOutput($label1='<<<<<<<',$label2='>>>>>>>',$label3='=======') {
        $lines = array();
        foreach ($this->_edits as $edit) {
            if ($edit->isConflict()) {
                /* FIXME: this should probably be moved somewhere else. */
                $lines = array_merge($lines,
                                     array($label1),
                                     $edit->final1,
                                     array($label3),
                                     $edit->final2,
                                     array($label2));
                $this->_conflictingBlocks++;
            } else {
                $lines = array_merge($lines, $edit->merged());
            }
        }

        return $lines;
    }

    /**
     * @access private
     *
     * @param array $edits1
     * @param array $edits2
     *
     * @return array
     */
    function _diff3($edits1, $edits2) {
        $edits = array();
        $bb = new _Diff3_BlockBuilder();

        $e1 = current($edits1);
        $e2 = current($edits2);
        while ($e1 || $e2) {
            if ($e1 && $e2 && is_a($e1, '_DiffOp_copy') && is_a($e2, '_DiffOp_copy')) {
                /* We have copy blocks from both diffs. This is the (only)
                 * time we want to emit a diff3 copy block.  Flush current
                 * diff3 diff block, if any. */
                if ($edit = $bb->finish()) {
                    $edits[] = $edit;
                }

                $ncopy = min($e1->norig(), $e2->norig());
                assert($ncopy > 0);
                $edits[] = new _Diff3_Op_copy(array_slice($e1->orig, 0, $ncopy));

                if ($e1->norig() > $ncopy) {
                    array_splice($e1->orig, 0, $ncopy);
                    array_splice($e1->closing, 0, $ncopy);
                } else {
                    $e1 = next($edits1);
                }

                if ($e2->norig() > $ncopy) {
                    array_splice($e2->orig, 0, $ncopy);
                    array_splice($e2->closing, 0, $ncopy);
                } else {
                    $e2 = next($edits2);
                }
            } else {
                if ($e1 && $e2) {
                    if ($e1->orig && $e2->orig) {
                        $norig = min($e1->norig(), $e2->norig());
                        $orig = array_splice($e1->orig, 0, $norig);
                        array_splice($e2->orig, 0, $norig);
                        $bb->input($orig);
                    }

                    if (is_a($e1, '_DiffOp_copy')) {
                        $bb->out1(array_splice($e1->closing, 0, $norig));
                    }

                    if (is_a($e2, '_DiffOp_copy')) {
                        $bb->out2(array_splice($e2->closing, 0, $norig));
                    }
                }

                if ($e1 && ! $e1->orig) {
                    $bb->out1($e1->closing);
                    $e1 = next($edits1);
                }
                if ($e2 && ! $e2->orig) {
                    $bb->out2($e2->closing);
                    $e2 = next($edits2);
                }
            }
        }

        if ($edit = $bb->finish()) {
            $edits[] = $edit;
        }

        return $edits;
    }
}

/**
 * @author  Geoffrey T. Dairiki <[email protected]>
 *
 * @access private
 */
class _Diff3_Op {

    function __construct($orig = false, $final1 = false, $final2 = false) {
        $this->orig = $orig ? $orig : array();
        $this->final1 = $final1 ? $final1 : array();
        $this->final2 = $final2 ? $final2 : array();
    }

    function merged() {
        if (!isset($this->_merged)) {
            if ($this->final1 === $this->final2) {
                $this->_merged = &$this->final1;
            } elseif ($this->final1 === $this->orig) {
                $this->_merged = &$this->final2;
            } elseif ($this->final2 === $this->orig) {
                $this->_merged = &$this->final1;
            } else {
                $this->_merged = false;
            }
        }

        return $this->_merged;
    }

    function isConflict() {
        return $this->merged() === false;
    }

}

/**
 * @author  Geoffrey T. Dairiki <[email protected]>
 *
 * @access private
 */
class _Diff3_Op_copy extends _Diff3_Op {

    function __construct($lines = false) {
        $this->orig = $lines ? $lines : array();
        $this->final1 = &$this->orig;
        $this->final2 = &$this->orig;
    }

    function merged() {
        return $this->orig;
    }

    function isConflict() {
        return false;
    }
}

/**
 * @author  Geoffrey T. Dairiki <[email protected]>
 *
 * @access private
 */
class _Diff3_BlockBuilder {

    function __construct() {
        $this->_init();
    }

    function input($lines) {
        if ($lines) {
            $this->_append($this->orig, $lines);
        }
    }

    function out1($lines) {
        if ($lines) {
            $this->_append($this->final1, $lines);
        }
    }

    function out2($lines) {
        if ($lines) {
            $this->_append($this->final2, $lines);
        }
    }

    function isEmpty() {
        return !$this->orig && !$this->final1 && !$this->final2;
    }

    function finish() {
        if ($this->isEmpty()) {
            return false;
        } else {
            $edit = new _Diff3_Op($this->orig, $this->final1, $this->final2);
            $this->_init();
            return $edit;
        }
    }

    function _init() {
        $this->orig = $this->final1 = $this->final2 = array();
    }

    function _append(&$array, $lines) {
        array_splice($array, sizeof($array), 0, $lines);
    }
}

//Setup VIM: ex: et ts=4 :

splitbrain / dokuwiki

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inc/DifferenceEngine.php (6 issues)

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