Index: upload.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/diff/Attic/upload.inc,v
retrieving revision 1.3.2.1
diff -u -r1.3.2.1 upload.inc
--- upload.inc	5 Mar 2008 21:00:52 -0000	1.3.2.1
+++ upload.inc	28 Mar 2008 01:35:16 -0000
@@ -36,7 +36,7 @@
     '#new' => $new_files,
     '#weight' => 30,
     '#format' => array(
-      'show_header' => false,
+      'show_header' => FALSE,
     )
   );
   return $result; 
Index: node.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/diff/Attic/node.inc,v
retrieving revision 1.2.2.1
diff -u -r1.2.2.1 node.inc
--- node.inc	5 Mar 2008 21:00:52 -0000	1.2.2.1
+++ node.inc	28 Mar 2008 01:35:16 -0000
@@ -14,7 +14,7 @@
     '#new' => array($new_node->title),
     '#weight' => -5,
     '#format' => array(
-      'show_header' => false,
+      'show_header' => FALSE,
     )
   );
   if ($type->has_body) {
Index: cck.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/diff/Attic/cck.inc,v
retrieving revision 1.2.2.1
diff -u -r1.2.2.1 cck.inc
--- cck.inc	5 Mar 2008 21:00:52 -0000	1.2.2.1
+++ cck.inc	28 Mar 2008 01:35:15 -0000
@@ -59,7 +59,7 @@
         '#new' => $new_values,
         '#weight' => $field['widget']['weight'],
         '#format' => array(
-          'show_header' => false,
+          'show_header' => FALSE,
         ),
       );
     }
Index: DiffEngine.php
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/diff/Attic/DiffEngine.php,v
retrieving revision 1.4.2.1
diff -u -r1.4.2.1 DiffEngine.php
--- DiffEngine.php	22 Feb 2008 12:51:28 -0000	1.4.2.1
+++ DiffEngine.php	28 Mar 2008 01:35:15 -0000
@@ -2,12 +2,11 @@
 // $Id: DiffEngine.php,v 1.4.2.1 2008/02/22 12:51:28 roetzi Exp $
 
 /**
-// A PHP diff engine for phpwiki. (Taken from phpwiki-1.3.3)
-//
-// Copyright (C) 2000, 2001 Geoffrey T. Dairiki <dairiki@dairiki.org>
-// You may copy this code freely under the conditions of the GPL.
-//
-*/
+ * A PHP diff engine for phpwiki. (Taken from phpwiki-1.3.3)
+ *
+ * Copyright (C) 2000, 2001 Geoffrey T. Dairiki <dairiki@dairiki.org>
+ * You may copy this code freely under the conditions of the GPL.
+ */
 
 define('USE_ASSERTS', FALSE);
 
@@ -17,21 +16,21 @@
  * @subpackage DifferenceEngine
  */
 class _DiffOp {
-	var $type;
-	var $orig;
-	var $closing;
-
-	function reverse() {
-		trigger_error('pure virtual', E_USER_ERROR);
-	}
-
-	function norig() {
-		return $this->orig ? sizeof($this->orig) : 0;
-	}
-
-	function nclosing() {
-		return $this->closing ? sizeof($this->closing) : 0;
-	}
+  var $type;
+  var $orig;
+  var $closing;
+
+  function reverse() {
+    trigger_error('pure virtual', E_USER_ERROR);
+  }
+
+  function norig() {
+    return $this->orig ? sizeof($this->orig) : 0;
+  }
+
+  function nclosing() {
+    return $this->closing ? sizeof($this->closing) : 0;
+  }
 }
 
 /**
@@ -40,18 +39,19 @@
  * @subpackage DifferenceEngine
  */
 class _DiffOp_Copy extends _DiffOp {
-	var $type = 'copy';
+  var $type = 'copy';
+
+  function _DiffOp_Copy($orig, $closing = FALSE) {
+    if (!is_array($closing)) {
+      $closing = $orig;
+    }
+    $this->orig = $orig;
+    $this->closing = $closing;
+  }
 
-	function _DiffOp_Copy ($orig, $closing = false) {
-		if (!is_array($closing))
-			$closing = $orig;
-		$this->orig = $orig;
-		$this->closing = $closing;
-	}
-
-	function reverse() {
-		return new _DiffOp_Copy($this->closing, $this->orig);
-	}
+  function reverse() {
+    return new _DiffOp_Copy($this->closing, $this->orig);
+  }
 }
 
 /**
@@ -60,16 +60,16 @@
  * @subpackage DifferenceEngine
  */
 class _DiffOp_Delete extends _DiffOp {
-	var $type = 'delete';
+  var $type = 'delete';
+
+  function _DiffOp_Delete($lines) {
+    $this->orig = $lines;
+    $this->closing = FALSE;
+  }
 
-	function _DiffOp_Delete ($lines) {
-		$this->orig = $lines;
-		$this->closing = false;
-	}
-
-	function reverse() {
-		return new _DiffOp_Add($this->orig);
-	}
+  function reverse() {
+    return new _DiffOp_Add($this->orig);
+  }
 }
 
 /**
@@ -78,16 +78,16 @@
  * @subpackage DifferenceEngine
  */
 class _DiffOp_Add extends _DiffOp {
-	var $type = 'add';
+  var $type = 'add';
+
+  function _DiffOp_Add($lines) {
+    $this->closing = $lines;
+    $this->orig = FALSE;
+  }
 
-	function _DiffOp_Add ($lines) {
-		$this->closing = $lines;
-		$this->orig = false;
-	}
-
-	function reverse() {
-		return new _DiffOp_Delete($this->closing);
-	}
+  function reverse() {
+    return new _DiffOp_Delete($this->closing);
+  }
 }
 
 /**
@@ -96,16 +96,16 @@
  * @subpackage DifferenceEngine
  */
 class _DiffOp_Change extends _DiffOp {
-	var $type = 'change';
+  var $type = 'change';
+
+  function _DiffOp_Change($orig, $closing) {
+    $this->orig = $orig;
+    $this->closing = $closing;
+  }
 
-	function _DiffOp_Change ($orig, $closing) {
-		$this->orig = $orig;
-		$this->closing = $closing;
-	}
-
-	function reverse() {
-		return new _DiffOp_Change($this->closing, $this->orig);
-	}
+  function reverse() {
+    return new _DiffOp_Change($this->closing, $this->orig);
+  }
 }
 
 
@@ -114,14 +114,14 @@
  *
  * 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
+ *   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
+ *   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
+ *   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.
@@ -134,401 +134,430 @@
  */
 class _DiffEngine
 {
-	function MAX_XREF_LENGTH() {
-		return 10000;
+  function MAX_XREF_LENGTH() {
+    return 10000;
+  }
+
+  function diff($from_lines, $to_lines) {
+
+    $n_from = sizeof($from_lines);
+    $n_to = sizeof($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++) {
+      $xhash[$this->_line_hash($from_lines[$xi])] = 1;
+    }
+
+    for ($yi = $skip; $yi < $n_to - $endskip; $yi++) {
+      $line = $to_lines[$yi];
+      if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) {
+        continue;
+      }
+      $yhash[$this->_line_hash($line)] = 1;
+      $this->yv[] = $line;
+      $this->yind[] = $yi;
+    }
+    for ($xi = $skip; $xi < $n_from - $endskip; $xi++) {
+      $line = $from_lines[$xi];
+      if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) {
+        continue;
+      }
+      $this->xv[] = $line;
+      $this->xind[] = $xi;
+    }
+
+    // Find the LCS.
+    $this->_compareseq(0, sizeof($this->xv), 0, sizeof($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 $edits;
+  }
+
+  /**
+   * Returns the whole line if it's small enough, or the MD5 hash otherwise.
+   */
+  function _line_hash($line) {
+    if (strlen($line) > $this->MAX_XREF_LENGTH()) {
+      return md5( line);
+    }
+    else {
+      return $line;
+    }
   }
 
-	function diff ($from_lines, $to_lines) {
 
-		$n_from = sizeof($from_lines);
-		$n_to = sizeof($to_lines);
+  /**
+   * 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.
+   */
+  function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) {
+    $flip = FALSE;
 
-		$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++) {
-			$xhash[$this->_line_hash($from_lines[$xi])] = 1;
-		}
-
-		for ($yi = $skip; $yi < $n_to - $endskip; $yi++) {
-			$line = $to_lines[$yi];
-			if ( ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) )
-				continue;
-			$yhash[$this->_line_hash($line)] = 1;
-			$this->yv[] = $line;
-			$this->yind[] = $yi;
-		}
-		for ($xi = $skip; $xi < $n_from - $endskip; $xi++) {
-			$line = $from_lines[$xi];
-			if ( ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) )
-				continue;
-			$this->xv[] = $line;
-			$this->xind[] = $xi;
-		}
-
-		// Find the LCS.
-		$this->_compareseq(0, sizeof($this->xv), 0, sizeof($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;
-	}
-
-	/**
-	 * Returns the whole line if it's small enough, or the MD5 hash otherwise
-	 */
-	function _line_hash( $line ) {
-		if ( strlen( $line ) > $this->MAX_XREF_LENGTH() ) {
-			return md5( $line );
-		} else {
-			return $line;
-		}
-	}
-
-
-	/* Divide the Largest Common Subsequence (LCS) of the sequences
-	 * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally
-	 * sized segments.
-	 *
-	 * Returns (LCS, PTS).	LCS is the length of the LCS. PTS is an
-	 * array of NCHUNKS+1 (X, Y) indexes giving the diving points between
-	 * sub sequences.  The first sub-sequence is contained in [X0, X1),
-	 * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on.  Note
-	 * that (X0, Y0) == (XOFF, YOFF) and
-	 * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM).
-	 *
-	 * This function assumes that the first lines of the specified portions
-	 * of the two files do not match, and likewise that the last lines do not
-	 * match.  The caller must trim matching lines from the beginning and end
-	 * of the portions it is going to specify.
-	 */
-	function _diag ($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]][] = $i;
-		else
-			for ($i = $ylim - 1; $i >= $yoff; $i--)
-				$ymatches[$this->yv[$i]][] = $i;
-
-		$this->lcs = 0;
-		$this->seq[0]= $yoff - 1;
-		$this->in_seq = array();
-		$ymids[0] = array();
-
-		$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];
-				reset($matches);
-				while (list ($junk, $y) = each($matches))
-					if (empty($this->in_seq[$y])) {
-						$k = $this->_lcs_pos($y);
-						USE_ASSERTS && assert($k > 0);
-						$ymids[$k] = $ymids[$k-1];
-						break;
-					}
-				while (list ($junk, $y) = each($matches)) {
-					if ($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];
-					}
-				}
-			}
-		}
-
-		$seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff);
-		$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 $this->{x,y}changed[], by
-	 * storing a 1 in the element for each line that is an insertion
-	 * or deletion (ie. is not in the LCS).
-	 *
-	 * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1.
-	 *
-	 * Note that XLIM, YLIM are exclusive bounds.
-	 * All line numbers are origin-0 and discarded lines are not counted.
-	 */
-	function _compareseq ($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 = $pt2;
-			}
-		}
-	}
-
-	/* Adjust inserts/deletes of identical lines to join changes
-	 * as much as possible.
-	 *
-	 * We do something when a run of changed lines include a
-	 * line at one end and has an excluded, identical line at the other.
-	 * We are free to choose which identical line is included.
-	 * `compareseq' usually chooses the one at the beginning,
-	 * but usually it is cleaner to consider the following identical line
-	 * to be the "change".
-	 *
-	 * This is extracted verbatim from analyze.c (GNU diffutils-2.7).
-	 */
-	function _shift_boundaries ($lines, &$changed, $other_changed) {
-		$i = 0;
-		$j = 0;
-
-		USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)');
-		$len = sizeof($lines);
-		$other_len = sizeof($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]');
-			}
-		}
-	}
+    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]][] = $i;
+      }
+    }
+    else {
+      for ($i = $ylim - 1; $i >= $yoff; $i--) {
+        $ymatches[$this->yv[$i]][] = $i;
+      }
+    }
+    $this->lcs = 0;
+    $this->seq[0]= $yoff - 1;
+    $this->in_seq = array();
+    $ymids[0] = array();
+
+    $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];
+        reset($matches);
+        while (list ($junk, $y) = each($matches)) {
+          if (empty($this->in_seq[$y])) {
+            $k = $this->_lcs_pos($y);
+            USE_ASSERTS && assert($k > 0);
+            $ymids[$k] = $ymids[$k-1];
+            break;
+          }
+        }
+        while (list ($junk, $y) = each($matches)) {
+          if ($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;
+          }
+          elseif (empty($this->in_seq[$y])) {
+            $k = $this->_lcs_pos($y);
+            USE_ASSERTS && assert($k > 0);
+            $ymids[$k] = $ymids[$k-1];
+          }
+        }
+      }
+    }
+
+    $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff);
+    $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 $this->{x,y}changed[], by
+   * storing a 1 in the element for each line that is an insertion
+   * or deletion (ie. is not in the LCS).
+   *
+   * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1.
+   *
+   * Note that XLIM, YLIM are exclusive bounds.
+   * All line numbers are origin-0 and discarded lines are not counted.
+   */
+  function _compareseq($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 = $pt2;
+      }
+    }
+  }
+
+  /**
+   * Adjust inserts/deletes of identical lines to join changes
+   * as much as possible.
+   *
+   * We do something when a run of changed lines include a
+   * line at one end and has an excluded, identical line at the other.
+   * We are free to choose which identical line is included.
+   * `compareseq' usually chooses the one at the beginning,
+   * but usually it is cleaner to consider the following identical line
+   * to be the "change".
+   *
+   * This is extracted verbatim from analyze.c (GNU diffutils-2.7).
+   */
+  function _shift_boundaries($lines, &$changed, $other_changed) {
+    $i = 0;
+    $j = 0;
+
+    USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)');
+    $len = sizeof($lines);
+    $other_len = sizeof($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]');
+      }
+    }
+  }
 }
 
 /**
@@ -539,134 +568,143 @@
  */
 class Diff
 {
-	var $edits;
+  var $edits;
 
-	/**
-	 * Constructor.
-	 * Computes diff between sequences of strings.
-	 *
-	 * @param $from_lines array An array of strings.
-	 *		  (Typically these are lines from a file.)
-	 * @param $to_lines array An array of strings.
-	 */
-	function Diff($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 object 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')
-				$lcs += sizeof($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($lines, sizeof($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($lines, sizeof($lines), 0, $edit->closing);
-		}
-		return $lines;
-	}
-
-	/**
-	 * Check a Diff for validity.
-	 *
-	 * This is here only for debugging purposes.
-	 */
-	function _check ($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);
-	}
+  /**
+   * Constructor.
+   * Computes diff between sequences of strings.
+   *
+   * @param $from_lines array An array of strings.
+   *      (Typically these are lines from a file.)
+   * @param $to_lines array An array of strings.
+   */
+  function Diff($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 object 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') {
+        $lcs += sizeof($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($lines, sizeof($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($lines, sizeof($lines), 0, $edit->closing);
+      }
+    }
+    return $lines;
+  }
+
+  /**
+   * Check a Diff for validity.
+   *
+   * This is here only for debugging purposes.
+   */
+  function _check ($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);
+  }
 }
 
 /**
@@ -677,52 +715,51 @@
  */
 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 $from_lines array An array of strings.
-	 *	(Typically these are lines from a file.)
-	 *
-	 * @param $to_lines array An array of strings.
-	 *
-	 * @param $mapped_from_lines array 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 $mapped_to_lines array This array should
-	 *	have the same number of elements as $to_lines.
-	 */
-	function MappedDiff($from_lines, $to_lines,
-						$mapped_from_lines, $mapped_to_lines) {
-
-		assert(sizeof($from_lines) == sizeof($mapped_from_lines));
-		assert(sizeof($to_lines) == sizeof($mapped_to_lines));
-
-		$this->Diff($mapped_from_lines, $mapped_to_lines);
-
-		$xi = $yi = 0;
-		for ($i = 0; $i < sizeof($this->edits); $i++) {
-			$orig = &$this->edits[$i]->orig;
-			if (is_array($orig)) {
-				$orig = array_slice($from_lines, $xi, sizeof($orig));
-				$xi += sizeof($orig);
-			}
-
-			$closing = &$this->edits[$i]->closing;
-			if (is_array($closing)) {
-				$closing = array_slice($to_lines, $yi, sizeof($closing));
-				$yi += sizeof($closing);
-			}
-		}
-	}
+  /**
+   * 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 $from_lines array An array of strings.
+   *  (Typically these are lines from a file.)
+   *
+   * @param $to_lines array An array of strings.
+   *
+   * @param $mapped_from_lines array 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 $mapped_to_lines array This array should
+   *  have the same number of elements as $to_lines.
+   */
+  function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) {
+
+    assert(sizeof($from_lines) == sizeof($mapped_from_lines));
+    assert(sizeof($to_lines) == sizeof($mapped_to_lines));
+
+    $this->Diff($mapped_from_lines, $mapped_to_lines);
+
+    $xi = $yi = 0;
+    for ($i = 0; $i < sizeof($this->edits); $i++) {
+      $orig = &$this->edits[$i]->orig;
+      if (is_array($orig)) {
+        $orig = array_slice($from_lines, $xi, sizeof($orig));
+        $xi += sizeof($orig);
+      }
+
+      $closing = &$this->edits[$i]->closing;
+      if (is_array($closing)) {
+        $closing = array_slice($to_lines, $yi, sizeof($closing));
+        $yi += sizeof($closing);
+      }
+    }
+  }
 }
 
 /**
@@ -740,161 +777,169 @@
   /**
    * Should a block header be shown?
    */
-  var $show_header = true;
+  var $show_header = TRUE;
   
-	/**
-	 * 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 $diff object A Diff object.
-	 * @return string The formatted output.
-	 */
-	function format($diff) {
-
-		$xi = $yi = 1;
-		$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($block)) {
-					if (sizeof($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, sizeof($context) - $nlead);
-					$x0 = $xi - sizeof($context);
-					$y0 = $yi - sizeof($context);
-					$block = array();
-					if ($context)
-						$block[] = new _DiffOp_Copy($context);
-				}
-				$block[] = $edit;
-			}
-
-			if ($edit->orig)
-				$xi += sizeof($edit->orig);
-			if ($edit->closing)
-				$yi += sizeof($edit->closing);
-		}
-
-		if (is_array($block))
-			$this->_block($x0, $xi - $x0,
-						  $y0, $yi - $y0,
-						  $block);
-
-		$end = $this->_end_diff();
-		return $end;
-	}
-
-	function _block($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 $val;
-	}
-
-	function _block_header($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') . $ybeg;
-	}
-
-	function _start_block($header) {
-		if ($this->show_header)
-  		echo $header;
-	}
-
-	function _end_block() {
-	}
-
-	function _lines($lines, $prefix = ' ') {
-		foreach ($lines as $line)
-			echo "$prefix $line\n";
-	}
-
-	function _context($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);
-	}
+  /**
+   * 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 $diff object A Diff object.
+   * @return string The formatted output.
+   */
+  function format($diff) {
+
+    $xi = $yi = 1;
+    $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($block)) {
+          if (sizeof($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, sizeof($context) - $nlead);
+          $x0 = $xi - sizeof($context);
+          $y0 = $yi - sizeof($context);
+          $block = array();
+          if ($context) {
+            $block[] = new _DiffOp_Copy($context);
+          }
+        }
+        $block[] = $edit;
+      }
+
+      if ($edit->orig) {
+        $xi += sizeof($edit->orig);
+      }
+      if ($edit->closing) {
+        $yi += sizeof($edit->closing);
+      }
+    }
+
+    if (is_array($block)) {
+      $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block);
+    }
+    $end = $this->_end_diff();
+    return $end;
+  }
+
+  function _block($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 $val;
+  }
+
+  function _block_header($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') . $ybeg;
+  }
+
+  function _start_block($header) {
+    if ($this->show_header) {
+      echo $header;
+    }
+  }
+
+  function _end_block() {
+  }
+
+  function _lines($lines, $prefix = ' ') {
+    foreach ($lines as $line) {
+      echo "$prefix $line\n";
+    }
+  }
+
+  function _context($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);
+  }
 }
 
 
 /**
- *	Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3
+ *  Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3
  *
  */
 
-define('NBSP', '&#160;');			// iso-8859-x non-breaking space.
+define('NBSP', '&#160;');      // iso-8859-x non-breaking space.
 
 /**
  * @todo document
@@ -902,56 +947,60 @@
  * @subpackage DifferenceEngine
  */
 class _HWLDF_WordAccumulator {
-	function _HWLDF_WordAccumulator () {
-		$this->_lines = array();
-		$this->_line = '';
-		$this->_group = '';
-		$this->_tag = '';
-	}
-
-	function _flushGroup ($new_tag) {
-		if ($this->_group !== '') {
-			if ($this->_tag == 'mark')
-				$this->_line .= '<span class="diffchange">' .
-					check_plain ( $this->_group ) . '</span>';
-			else
-				$this->_line .= check_plain ( $this->_group );
-		}
-		$this->_group = '';
-		$this->_tag = $new_tag;
-	}
-
-	function _flushLine ($new_tag) {
-		$this->_flushGroup($new_tag);
-		if ($this->_line != '')
-			array_push ( $this->_lines, $this->_line );
-		else
-			# make empty lines visible by inserting an NBSP
-			array_push ( $this->_lines, NBSP );
-		$this->_line = '';
-	}
-
-	function addWords ($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") {
-				$this->_flushLine($tag);
-				$word = substr($word, 1);
-			}
-			assert(!strstr($word, "\n"));
-			$this->_group .= $word;
-		}
-	}
-
-	function getLines() {
-		$this->_flushLine('~done');
-		return $this->_lines;
-	}
+  function _HWLDF_WordAccumulator() {
+    $this->_lines = array();
+    $this->_line = '';
+    $this->_group = '';
+    $this->_tag = '';
+  }
+
+  function _flushGroup($new_tag) {
+    if ($this->_group !== '') {
+      if ($this->_tag == 'mark') {
+        $this->_line .= '<span class="diffchange">'. check_plain($this->_group) .'</span>';
+      }
+      else {
+        $this->_line .= check_plain($this->_group);
+      }
+    }
+    $this->_group = '';
+    $this->_tag = $new_tag;
+  }
+
+  function _flushLine($new_tag) {
+    $this->_flushGroup($new_tag);
+    if ($this->_line != '') {
+      array_push ( $this->_lines, $this->_line );
+    }
+    else {
+      // make empty lines visible by inserting an NBSP
+      array_push($this->_lines, NBSP);
+    }
+    $this->_line = '';
+  }
+
+  function addWords ($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") {
+        $this->_flushLine($tag);
+        $word = substr($word, 1);
+      }
+      assert(!strstr($word, "\n"));
+      $this->_group .= $word;
+    }
+  }
+
+  function getLines() {
+    $this->_flushLine('~done');
+    return $this->_lines;
+  }
 }
 
 /**
@@ -961,73 +1010,74 @@
  */
 class WordLevelDiff extends MappedDiff
 {
-	function MAX_LINE_LENGTH() {
-		return 10000;
+  function MAX_LINE_LENGTH() {
+    return 10000;
   }
 
-	function WordLevelDiff ($orig_lines, $closing_lines) {
+  function WordLevelDiff($orig_lines, $closing_lines) {
+    list($orig_words, $orig_stripped) = $this->_split($orig_lines);
+    list($closing_words, $closing_stripped) = $this->_split($closing_lines);
 
-		list ($orig_words, $orig_stripped) = $this->_split($orig_lines);
-		list ($closing_words, $closing_stripped) = $this->_split($closing_lines);
+    $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped);
+  }
+
+  function _split($lines) {
+    $words = array();
+    $stripped = array();
+    $first = TRUE;
+    foreach ($lines as $line) {
+      // If the line is too long, just pretend the entire line is one big word
+      // This prevents resource exhaustion problems
+      if ( $first ) {
+        $first = FALSE;
+      }
+      else {
+        $words[] = "\n";
+        $stripped[] = "\n";
+      }
+      if ( strlen( $line ) > $this->MAX_LINE_LENGTH() ) {
+        $words[] = $line;
+        $stripped[] = $line;
+      }
+      else {
+        if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) {
+          $words = array_merge($words, $m[0]);
+          $stripped = array_merge($stripped, $m[1]);
+        }
+      }
+    }
+    return array($words, $stripped);
+  }
+
+  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');
+      }
+    }
+    $lines = $orig->getLines();
+    return $lines;
+  }
+
+  function closing() {
+    $closing = new _HWLDF_WordAccumulator;
 
-		$this->MappedDiff($orig_words, $closing_words,
-						  $orig_stripped, $closing_stripped);
-	}
-
-	function _split($lines) {
-
-		$words = array();
-		$stripped = array();
-		$first = true;
-		foreach ( $lines as $line ) {
-			# If the line is too long, just pretend the entire line is one big word
-			# This prevents resource exhaustion problems
-			if ( $first ) {
-				$first = false;
-			} else {
-				$words[] = "\n";
-				$stripped[] = "\n";
-			}
-			if ( strlen( $line ) > $this->MAX_LINE_LENGTH() ) {
-				$words[] = $line;
-				$stripped[] = $line;
-			} else {
-				if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs',
-					$line, $m))
-				{
-					$words = array_merge( $words, $m[0] );
-					$stripped = array_merge( $stripped, $m[1] );
-				}
-			}
-		}
-		return array($words, $stripped);
-	}
-
-	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');
-		}
-		$lines = $orig->getLines();
-		return $lines;
-	}
-
-	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');
-		}
-		$lines = $closing->getLines();
-		return $lines;
-	}
+    foreach ($this->edits as $edit) {
+      if ($edit->type == 'copy') {
+        $closing->addWords($edit->closing);
+      }
+      elseif ($edit->closing) {
+        $closing->addWords($edit->closing, 'mark');
+      }
+    }
+    $lines = $closing->getLines();
+    return $lines;
+  }
 }
 
 /**
@@ -1035,8 +1085,7 @@
  * @private
  * @subpackage DifferenceEngine
  */
-class DrupalDiffFormatter extends DiffFormatter
-{
+class DrupalDiffFormatter extends DiffFormatter {
 
   var $rows;
 
@@ -1057,11 +1106,11 @@
     return array(
       array(
         'data' => theme('diff_header_line', $xbeg),
-        'colspan' => 2
+        'colspan' => 2,
       ),
       array(
         'data' => theme('diff_header_line', $ybeg),
-        'colspan' => 2
+        'colspan' => 2,
       )
     );
   }
Index: taxonomy.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/diff/Attic/taxonomy.inc,v
retrieving revision 1.2.2.2
diff -u -r1.2.2.2 taxonomy.inc
--- taxonomy.inc	5 Mar 2008 21:00:52 -0000	1.2.2.2
+++ taxonomy.inc	28 Mar 2008 01:35:16 -0000
@@ -50,7 +50,7 @@
     '#new' => $new_taxonomy,
     '#weight' => -3,
     '#format' => array(
-      'show_header' => false,
+      'show_header' => FALSE,
     )
   );
   return $result;
Index: diff.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/diff/Attic/diff.module,v
retrieving revision 1.23.2.3.2.1
diff -u -r1.23.2.3.2.1 diff.module
--- diff.module	13 Mar 2008 16:47:07 -0000	1.23.2.3.2.1
+++ diff.module	28 Mar 2008 01:35:16 -0000
@@ -339,7 +339,7 @@
   }
 
   $rows = array();
-  $any_visible_change = false;
+  $any_visible_change = FALSE;
   $node_diffs = module_invoke_all('diff', $old_node, $new_node);
   
   // We start off assuming all form elements are in the correct order.
@@ -381,7 +381,7 @@
         )
       );
       $rows = array_merge($rows, $diff_rows);
-      $any_visible_change = true;
+      $any_visible_change = TRUE;
     }
   }
   if (!$any_visible_change) {
@@ -405,7 +405,7 @@
 
 /**
  * Get the entry in the revisions list after $vid.
- * Returns false if $vid is the last entry.
+ * Returns FALSE if $vid is the last entry.
  *
  * @param $node_revisions
  *   Array of node revision IDs in descending order.
@@ -416,16 +416,16 @@
   $previous = NULL;
   foreach($node_revisions as $revision) {
     if ($revision->vid == $vid) {
-      return ($previous ? $previous->vid : false);
+      return ($previous ? $previous->vid : FALSE);
     }
     $previous = $revision;
   }
-  return false;
+  return FALSE;
 }
 
 /**
  * Get the entry in the revision list before $vid.
- * Returns false if $vid is the first entry.
+ * Returns FALSE if $vid is the first entry.
  *
  * @param $node_revisions
  *   Array of node revision IDs in descending order.
@@ -440,7 +440,7 @@
     }
     $previous = $revision;
   }
-  return false;
+  return FALSE;
 }
 
 /**
