From 222b01f5169f1c7e69762e0e8904c24f78f71882 Mon Sep 17 00:00:00 2001 From: Pierre Schmitz Date: Wed, 28 Jul 2010 11:52:48 +0200 Subject: update to MediaWiki 1.16.0 --- includes/diff/DifferenceEngine.php | 933 ------------------------------ includes/diff/DifferenceInterface.php | 1021 +++++++++++++++++++++++++++++++++ includes/diff/HTMLDiff.php | 1009 -------------------------------- includes/diff/Nodes.php | 439 -------------- 4 files changed, 1021 insertions(+), 2381 deletions(-) create mode 100644 includes/diff/DifferenceInterface.php delete mode 100644 includes/diff/HTMLDiff.php delete mode 100644 includes/diff/Nodes.php (limited to 'includes/diff') diff --git a/includes/diff/DifferenceEngine.php b/includes/diff/DifferenceEngine.php index aa48f9f3..184d1fc2 100644 --- a/includes/diff/DifferenceEngine.php +++ b/includes/diff/DifferenceEngine.php @@ -3,939 +3,6 @@ * @defgroup DifferenceEngine DifferenceEngine */ -/** - * Constant to indicate diff cache compatibility. - * Bump this when changing the diff formatting in a way that - * fixes important bugs or such to force cached diff views to - * clear. - */ -define( 'MW_DIFF_VERSION', '1.11a' ); - -/** - * @todo document - * @ingroup DifferenceEngine - */ -class DifferenceEngine { - /**#@+ - * @private - */ - var $mOldid, $mNewid, $mTitle; - var $mOldtitle, $mNewtitle, $mPagetitle; - var $mOldtext, $mNewtext; - var $mOldPage, $mNewPage; - var $mRcidMarkPatrolled; - var $mOldRev, $mNewRev; - var $mRevisionsLoaded = false; // Have the revisions been loaded - var $mTextLoaded = 0; // How many text blobs have been loaded, 0, 1 or 2? - var $mCacheHit = false; // Was the diff fetched from cache? - var $htmldiff; - - protected $unhide = false; - /**#@-*/ - - /** - * Constructor - * @param $titleObj Title object that the diff is associated with - * @param $old Integer: old ID we want to show and diff with. - * @param $new String: either 'prev' or 'next'. - * @param $rcid Integer: ??? FIXME (default 0) - * @param $refreshCache boolean If set, refreshes the diff cache - * @param $htmldiff boolean If set, output using HTMLDiff instead of raw wikicode diff - * @param $unhide boolean If set, allow viewing deleted revs - */ - function __construct( $titleObj = null, $old = 0, $new = 0, $rcid = 0, $refreshCache = false , $htmldiff = false, $unhide = false ) { - $this->mTitle = $titleObj; - wfDebug("DifferenceEngine old '$old' new '$new' rcid '$rcid'\n"); - - if ( 'prev' === $new ) { - # Show diff between revision $old and the previous one. - # Get previous one from DB. - $this->mNewid = intval($old); - $this->mOldid = $this->mTitle->getPreviousRevisionID( $this->mNewid ); - } elseif ( 'next' === $new ) { - # Show diff between revision $old and the next one. - # Get next one from DB. - $this->mOldid = intval($old); - $this->mNewid = $this->mTitle->getNextRevisionID( $this->mOldid ); - if ( false === $this->mNewid ) { - # if no result, NewId points to the newest old revision. The only newer - # revision is cur, which is "0". - $this->mNewid = 0; - } - } else { - $this->mOldid = intval($old); - $this->mNewid = intval($new); - wfRunHooks( 'NewDifferenceEngine', array(&$titleObj, &$this->mOldid, &$this->mNewid, $old, $new) ); - } - $this->mRcidMarkPatrolled = intval($rcid); # force it to be an integer - $this->mRefreshCache = $refreshCache; - $this->htmldiff = $htmldiff; - $this->unhide = $unhide; - } - - function getTitle() { - return $this->mTitle; - } - - function wasCacheHit() { - return $this->mCacheHit; - } - - function getOldid() { - return $this->mOldid; - } - - function getNewid() { - return $this->mNewid; - } - - function showDiffPage( $diffOnly = false ) { - global $wgUser, $wgOut, $wgUseExternalEditor, $wgUseRCPatrol, $wgEnableHtmlDiff; - wfProfileIn( __METHOD__ ); - - - # If external diffs are enabled both globally and for the user, - # we'll use the application/x-external-editor interface to call - # an external diff tool like kompare, kdiff3, etc. - if($wgUseExternalEditor && $wgUser->getOption('externaldiff')) { - global $wgInputEncoding,$wgServer,$wgScript,$wgLang; - $wgOut->disable(); - header ( "Content-type: application/x-external-editor; charset=".$wgInputEncoding ); - $url1=$this->mTitle->getFullURL("action=raw&oldid=".$this->mOldid); - $url2=$this->mTitle->getFullURL("action=raw&oldid=".$this->mNewid); - $special=$wgLang->getNsText(NS_SPECIAL); - $control=<<setArticleFlag( false ); - if ( !$this->loadRevisionData() ) { - $t = $this->mTitle->getPrefixedText(); - $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid ); - $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) ); - $wgOut->addWikiMsg( 'missing-article', "$t", $d ); - wfProfileOut( __METHOD__ ); - return; - } - - wfRunHooks( 'DiffViewHeader', array( $this, $this->mOldRev, $this->mNewRev ) ); - - if ( $this->mNewRev->isCurrent() ) { - $wgOut->setArticleFlag( true ); - } - - # mOldid is false if the difference engine is called with a "vague" query for - # a diff between a version V and its previous version V' AND the version V - # is the first version of that article. In that case, V' does not exist. - if ( $this->mOldid === false ) { - $this->showFirstRevision(); - $this->renderNewRevision(); // should we respect $diffOnly here or not? - wfProfileOut( __METHOD__ ); - return; - } - - $wgOut->suppressQuickbar(); - - $oldTitle = $this->mOldPage->getPrefixedText(); - $newTitle = $this->mNewPage->getPrefixedText(); - if( $oldTitle == $newTitle ) { - $wgOut->setPageTitle( $newTitle ); - } else { - $wgOut->setPageTitle( $oldTitle . ', ' . $newTitle ); - } - $wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) ); - $wgOut->setRobotPolicy( 'noindex,nofollow' ); - - if ( !$this->mOldPage->userCanRead() || !$this->mNewPage->userCanRead() ) { - $wgOut->loginToUse(); - $wgOut->output(); - $wgOut->disable(); - wfProfileOut( __METHOD__ ); - return; - } - - $sk = $wgUser->getSkin(); - - // Check if page is editable - $editable = $this->mNewRev->getTitle()->userCan( 'edit' ); - if ( $editable && $this->mNewRev->isCurrent() && $wgUser->isAllowed( 'rollback' ) ) { - $rollback = '   ' . $sk->generateRollback( $this->mNewRev ); - } else { - $rollback = ''; - } - - // Prepare a change patrol link, if applicable - if( $wgUseRCPatrol && $this->mTitle->userCan('patrol') ) { - // If we've been given an explicit change identifier, use it; saves time - if( $this->mRcidMarkPatrolled ) { - $rcid = $this->mRcidMarkPatrolled; - $rc = RecentChange::newFromId( $rcid ); - // Already patrolled? - $rcid = is_object($rc) && !$rc->getAttribute('rc_patrolled') ? $rcid : 0; - } else { - // Look for an unpatrolled change corresponding to this diff - $db = wfGetDB( DB_SLAVE ); - $change = RecentChange::newFromConds( - array( - // Add redundant user,timestamp condition so we can use the existing index - 'rc_user_text' => $this->mNewRev->getRawUserText(), - 'rc_timestamp' => $db->timestamp( $this->mNewRev->getTimestamp() ), - 'rc_this_oldid' => $this->mNewid, - 'rc_last_oldid' => $this->mOldid, - 'rc_patrolled' => 0 - ), - __METHOD__ - ); - if( $change instanceof RecentChange ) { - $rcid = $change->mAttribs['rc_id']; - $this->mRcidMarkPatrolled = $rcid; - } else { - // None found - $rcid = 0; - } - } - // Build the link - if( $rcid ) { - $patrol = ' [' . $sk->makeKnownLinkObj( $this->mTitle, - wfMsgHtml( 'markaspatrolleddiff' ), "action=markpatrolled&rcid={$rcid}" ) . ']'; - } else { - $patrol = ''; - } - } else { - $patrol = ''; - } - - $diffOnlyArg = ''; - # Carry over 'diffonly' param via navigation links - if( $diffOnly != $wgUser->getBoolOption('diffonly') ) { - $diffOnlyArg = '&diffonly='.$diffOnly; - } - $htmldiffarg = $this->htmlDiffArgument(); - # Make "previous revision link" - $prevlink = $sk->makeKnownLinkObj( $this->mTitle, wfMsgHtml( 'previousdiff' ), - "diff=prev&oldid={$this->mOldid}{$htmldiffarg}{$diffOnlyArg}", '', '', 'id="differences-prevlink"' ); - # Make "next revision link" - if( $this->mNewRev->isCurrent() ) { - $nextlink = ' '; - } else { - $nextlink = $sk->makeKnownLinkObj( $this->mTitle, wfMsgHtml( 'nextdiff' ), - "diff=next&oldid={$this->mNewid}{$htmldiffarg}{$diffOnlyArg}", '', '', 'id="differences-nextlink"' ); - } - - $oldminor = ''; - $newminor = ''; - - if( $this->mOldRev->isMinor() ) { - $oldminor = Xml::span( wfMsg( 'minoreditletter' ), 'minor' ) . ' '; - } - if( $this->mNewRev->isMinor() ) { - $newminor = Xml::span( wfMsg( 'minoreditletter' ), 'minor' ) . ' '; - } - - $rdel = ''; $ldel = ''; - if( $wgUser->isAllowed( 'deleterevision' ) ) { - if( !$this->mOldRev->userCan( Revision::DELETED_RESTRICTED ) ) { - // If revision was hidden from sysops - $ldel = Xml::tags( 'span', array( 'class'=>'mw-revdelundel-link' ), '('.wfMsgHtml( 'rev-delundel' ).')' ); - } else { - $query = array( 'target' => $this->mOldRev->mTitle->getPrefixedDbkey(), - 'oldid' => $this->mOldRev->getId() - ); - $ldel = $sk->revDeleteLink( $query, $this->mOldRev->isDeleted( Revision::DELETED_RESTRICTED ) ); - } - $ldel = "   $ldel "; - // We don't currently handle well changing the top revision's settings - if( $this->mNewRev->isCurrent() ) { - $rdel = Xml::tags( 'span', array( 'class'=>'mw-revdelundel-link' ), '('.wfMsgHtml( 'rev-delundel' ).')' ); - } else if( !$this->mNewRev->userCan( Revision::DELETED_RESTRICTED ) ) { - // If revision was hidden from sysops - $rdel = Xml::tags( 'span', array( 'class'=>'mw-revdelundel-link' ), '('.wfMsgHtml( 'rev-delundel' ).')' ); - } else { - $query = array( 'target' => $this->mNewRev->mTitle->getPrefixedDbkey(), - 'oldid' => $this->mNewRev->getId() - ); - $rdel = $sk->revDeleteLink( $query, $this->mNewRev->isDeleted( Revision::DELETED_RESTRICTED ) ); - } - $rdel = "   $rdel "; - } - - $oldHeader = '
'.$this->mOldtitle.'
' . - '
' . $sk->revUserTools( $this->mOldRev, !$this->unhide ) . "
" . - '
' . $oldminor . $sk->revComment( $this->mOldRev, !$diffOnly, !$this->unhide ).$ldel."
" . - '
' . $prevlink .'
'; - $newHeader = '
'.$this->mNewtitle.'
' . - '
' . $sk->revUserTools( $this->mNewRev, !$this->unhide ) . " $rollback
" . - '
' . $newminor . $sk->revComment( $this->mNewRev, !$diffOnly, !$this->unhide ).$rdel."
" . - '
' . $nextlink . $patrol . '
'; - - # Check if this user can see the revisions - $allowed = $this->mOldRev->userCan(Revision::DELETED_TEXT) - && $this->mNewRev->userCan(Revision::DELETED_TEXT); - $deleted = $this->mOldRev->isDeleted(Revision::DELETED_TEXT) - || $this->mNewRev->isDeleted(Revision::DELETED_TEXT); - # Output the diff if allowed... - if( $deleted && (!$this->unhide || !$allowed) ) { - $this->showDiffStyle(); - $multi = $this->getMultiNotice(); - $wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) ); - if( !$allowed ) { - # Give explanation for why revision is not visible - $wgOut->wrapWikiMsg( "
\n$1
\n", - array( 'rev-deleted-no-diff' ) ); - } else { - # Give explanation and add a link to view the diff... - $link = $this->mTitle->getFullUrl( "diff={$this->mNewid}&oldid={$this->mOldid}". - '&unhide=1&token='.urlencode( $wgUser->editToken($this->mNewid) ) ); - $wgOut->wrapWikiMsg( "
\n$1
\n", - array( 'rev-deleted-unhide-diff', $link ) ); - } - } else if( $wgEnableHtmlDiff && $this->htmldiff ) { - $multi = $this->getMultiNotice(); - $wgOut->addHTML('
'.$sk->makeKnownLinkObj( $this->mTitle, wfMsgHtml( 'wikicodecomparison' ), - 'diff='.$this->mNewid.'&oldid='.$this->mOldid.'&htmldiff=0', '', '', 'id="differences-switchtype"' ).'
'); - $wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) ); - $this->renderHtmlDiff(); - } else { - if( $wgEnableHtmlDiff ) { - $wgOut->addHTML('
'.$sk->makeKnownLinkObj( $this->mTitle, wfMsgHtml( 'visualcomparison' ), - 'diff='.$this->mNewid.'&oldid='.$this->mOldid.'&htmldiff=1', '', '', 'id="differences-switchtype"' ).'
'); - } - $this->showDiff( $oldHeader, $newHeader ); - if( !$diffOnly ) { - $this->renderNewRevision(); - } - } - wfProfileOut( __METHOD__ ); - } - - /** - * Show the new revision of the page. - */ - function renderNewRevision() { - global $wgOut, $wgUser; - wfProfileIn( __METHOD__ ); - - $wgOut->addHTML( "

{$this->mPagetitle}

\n" ); - # Add deleted rev tag if needed - if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) { - $wgOut->wrapWikiMsg( "
\n$1
\n", 'rev-deleted-text-permission' ); - } else if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) { - $wgOut->wrapWikiMsg( "
\n$1
\n", 'rev-deleted-text-view' ); - } - - if( !$this->mNewRev->isCurrent() ) { - $oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false ); - } - - $this->loadNewText(); - if( is_object( $this->mNewRev ) ) { - $wgOut->setRevisionId( $this->mNewRev->getId() ); - } - - if( $this->mTitle->isCssJsSubpage() || $this->mTitle->isCssOrJsPage() ) { - // Stolen from Article::view --AG 2007-10-11 - // Give hooks a chance to customise the output - if( wfRunHooks( 'ShowRawCssJs', array( $this->mNewtext, $this->mTitle, $wgOut ) ) ) { - // Wrap the whole lot in a 
 and don't parse
-				$m = array();
-				preg_match( '!\.(css|js)$!u', $this->mTitle->getText(), $m );
-				$wgOut->addHTML( "
\n" );
-				$wgOut->addHTML( htmlspecialchars( $this->mNewtext ) );
-				$wgOut->addHTML( "\n
\n" );
-			}
-		} else {
-			$wgOut->addWikiTextTidy( $this->mNewtext );
-		}
-
-		if( is_object( $this->mNewRev ) && !$this->mNewRev->isCurrent() ) {
-			$wgOut->parserOptions()->setEditSection( $oldEditSectionSetting );
-		}
-		# Add redundant patrol link on bottom...
-		if( $this->mRcidMarkPatrolled && $this->mTitle->quickUserCan('patrol') ) {
-			$sk = $wgUser->getSkin();
-			$wgOut->addHTML(
-				"
[" . $sk->makeKnownLinkObj( $this->mTitle, 
-					wfMsgHtml( 'markaspatrolleddiff' ), "action=markpatrolled&rcid={$this->mRcidMarkPatrolled}" ) .
-				']
'
-			 );
-		}
-
-		wfProfileOut( __METHOD__ );
-	}
-
-
-	function renderHtmlDiff() {
-		global $wgOut, $wgTitle, $wgParser, $wgDebugComments;
-		wfProfileIn( __METHOD__ );
-
-		$this->showDiffStyle();
-
-		$wgOut->addHTML( '
'.wfMsgHtml( 'visual-comparison' )."
\n" );
-		#add deleted rev tag if needed
-		if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
-			$wgOut->wrapWikiMsg( "
\n$1
\n", 'rev-deleted-text-permission' );
-		} else if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
-			$wgOut->wrapWikiMsg( "
\n$1
\n", 'rev-deleted-text-view' );
-		}
-
-		if( !$this->mNewRev->isCurrent() ) {
-			$oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false );
-		}
-
-		$this->loadText();
-
-		// Old revision
-		if( is_object( $this->mOldRev ) ) {
-			$wgOut->setRevisionId( $this->mOldRev->getId() );
-		}
-
-		$popts = $wgOut->parserOptions();
-		$oldTidy = $popts->setTidy( true );
-		$popts->setEditSection( false );
-
-		$parserOutput = $wgParser->parse( $this->mOldtext, $wgTitle, $popts, true, true, $wgOut->getRevisionId() );
-		$popts->setTidy( $oldTidy );
-
-		//only for new?
-		//$wgOut->addParserOutputNoText( $parserOutput );
-		$oldHtml = $parserOutput->getText();
-		wfRunHooks( 'OutputPageBeforeHTML', array( &$wgOut, &$oldHtml ) );
-
-		// New revision
-		if( is_object( $this->mNewRev ) ) {
-			$wgOut->setRevisionId( $this->mNewRev->getId() );
-		}
-
-		$popts = $wgOut->parserOptions();
-		$oldTidy = $popts->setTidy( true );
-
-		$parserOutput = $wgParser->parse( $this->mNewtext, $wgTitle, $popts, true, true, $wgOut->getRevisionId() );
-		$popts->setTidy( $oldTidy );
-
-		$wgOut->addParserOutputNoText( $parserOutput );
-		$newHtml = $parserOutput->getText();
-		wfRunHooks( 'OutputPageBeforeHTML', array( &$wgOut, &$newHtml ) );
-
-		unset($parserOutput, $popts);
-
-		$differ = new HTMLDiffer(new DelegatingContentHandler($wgOut));
-		$differ->htmlDiff($oldHtml, $newHtml);
-		if ( $wgDebugComments ) {
-			$wgOut->addHTML( "\n" );
-		}
-
-		wfProfileOut( __METHOD__ );
-	}
-
-	/**
-	 * Show the first revision of an article. Uses normal diff headers in
-	 * contrast to normal "old revision" display style.
-	 */
-	function showFirstRevision() {
-		global $wgOut, $wgUser;
-		wfProfileIn( __METHOD__ );
-
-		# Get article text from the DB
-		#
-		if ( ! $this->loadNewText() ) {
-			$t = $this->mTitle->getPrefixedText();
-			$d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
-			$wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
-			$wgOut->addWikiMsg( 'missing-article', "$t", $d );
-			wfProfileOut( __METHOD__ );
-			return;
-		}
-		if ( $this->mNewRev->isCurrent() ) {
-			$wgOut->setArticleFlag( true );
-		}
-
-		# Check if user is allowed to look at this page. If not, bail out.
-		#
-		if ( !$this->mTitle->userCanRead() ) {
-			$wgOut->loginToUse();
-			$wgOut->output();
-			wfProfileOut( __METHOD__ );
-			throw new MWException("Permission Error: you do not have access to view this page");
-		}
-
-		# Prepare the header box
-		#
-		$sk = $wgUser->getSkin();
-
-		$next = $this->mTitle->getNextRevisionID( $this->mNewid );
-		if( !$next ) {
-			$nextlink = '';
-		} else {
-			$nextlink = '
' . $sk->makeKnownLinkObj( $this->mTitle, wfMsgHtml( 'nextdiff' ), 
-				'diff=next&oldid=' . $this->mNewid.$this->htmlDiffArgument(), '', '', 'id="differences-nextlink"' );
-		}
-		$header = "
" .
-			$sk->revUserTools( $this->mNewRev ) . "
" . $sk->revComment( $this->mNewRev ) . $nextlink . "
\n";
-
-		$wgOut->addHTML( $header );
-
-		$wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
-		$wgOut->setRobotPolicy( 'noindex,nofollow' );
-
-		wfProfileOut( __METHOD__ );
-	}
-
-	function htmlDiffArgument(){
-		global $wgEnableHtmlDiff;
-		if($wgEnableHtmlDiff){
-			if($this->htmldiff){
-				return '&htmldiff=1';
-			}else{
-				return '&htmldiff=0';
-			}
-		}else{
-			return '';
-		}
-	}
-
-	/**
-	 * Get the diff text, send it to $wgOut
-	 * Returns false if the diff could not be generated, otherwise returns true
-	 */
-	function showDiff( $otitle, $ntitle ) {
-		global $wgOut;
-		$diff = $this->getDiff( $otitle, $ntitle );
-		if ( $diff === false ) {
-			$wgOut->addWikiMsg( 'missing-article', "(fixme, bug)", '' );
-			return false;
-		} else {
-			$this->showDiffStyle();
-			$wgOut->addHTML( $diff );
-			return true;
-		}
-	}
-
-	/**
-	 * Add style sheets and supporting JS for diff display.
-	 */
-	function showDiffStyle() {
-		global $wgStylePath, $wgStyleVersion, $wgOut;
-		$wgOut->addStyle( 'common/diff.css' );
-
-		// JS is needed to detect old versions of Mozilla to work around an annoyance bug.
-		$wgOut->addScript( "" );
-	}
-
-	/**
-	 * Get complete diff table, including header
-	 *
-	 * @param Title $otitle Old title
-	 * @param Title $ntitle New title
-	 * @return mixed
-	 */
-	function getDiff( $otitle, $ntitle ) {
-		$body = $this->getDiffBody();
-		if ( $body === false ) {
-			return false;
-		} else {
-			$multi = $this->getMultiNotice();
-			return $this->addHeader( $body, $otitle, $ntitle, $multi );
-		}
-	}
-
-	/**
-	 * Get the diff table body, without header
-	 *
-	 * @return mixed
-	 */
-	function getDiffBody() {
-		global $wgMemc;
-		wfProfileIn( __METHOD__ );
-		$this->mCacheHit = true;
-		// Check if the diff should be hidden from this user
-		if ( !$this->loadRevisionData() )
-			return '';
-		if ( $this->mOldRev && !$this->mOldRev->userCan(Revision::DELETED_TEXT) ) {
-			return '';
-		} else if ( $this->mNewRev && !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
-			return '';
-		} else if ( $this->mOldRev && $this->mNewRev && $this->mOldRev->getID() == $this->mNewRev->getID() ) {
-			return '';
-		}
-		// Cacheable?
-		$key = false;
-		if ( $this->mOldid && $this->mNewid ) {
-			$key = wfMemcKey( 'diff', 'version', MW_DIFF_VERSION, 'oldid', $this->mOldid, 'newid', $this->mNewid );
-			// Try cache
-			if ( !$this->mRefreshCache ) {
-				$difftext = $wgMemc->get( $key );
-				if ( $difftext ) {
-					wfIncrStats( 'diff_cache_hit' );
-					$difftext = $this->localiseLineNumbers( $difftext );
-					$difftext .= "\n\n";
-					wfProfileOut( __METHOD__ );
-					return $difftext;
-				}
-			} // don't try to load but save the result
-		}
-		$this->mCacheHit = false;
-
-		// Loadtext is permission safe, this just clears out the diff
-		if ( !$this->loadText() ) {
-			wfProfileOut( __METHOD__ );
-			return false;
-		}
-
-		$difftext = $this->generateDiffBody( $this->mOldtext, $this->mNewtext );
-
-		// Save to cache for 7 days
-		if ( !wfRunHooks( 'AbortDiffCache', array( &$this ) ) ) {
-			wfIncrStats( 'diff_uncacheable' );
-		} else if ( $key !== false && $difftext !== false ) {
-			wfIncrStats( 'diff_cache_miss' );
-			$wgMemc->set( $key, $difftext, 7*86400 );
-		} else {
-			wfIncrStats( 'diff_uncacheable' );
-		}
-		// Replace line numbers with the text in the user's language
-		if ( $difftext !== false ) {
-			$difftext = $this->localiseLineNumbers( $difftext );
-		}
-		wfProfileOut( __METHOD__ );
-		return $difftext;
-	}
-
-	/**
-	 * Generate a diff, no caching
-	 * $otext and $ntext must be already segmented
-	 */
-	function generateDiffBody( $otext, $ntext ) {
-		global $wgExternalDiffEngine, $wgContLang;
-
-		$otext = str_replace( "\r\n", "\n", $otext );
-		$ntext = str_replace( "\r\n", "\n", $ntext );
-
-		if ( $wgExternalDiffEngine == 'wikidiff' ) {
-			# For historical reasons, external diff engine expects
-			# input text to be HTML-escaped already
-			$otext = htmlspecialchars ( $wgContLang->segmentForDiff( $otext ) );
-			$ntext = htmlspecialchars ( $wgContLang->segmentForDiff( $ntext ) );
-			if( !function_exists( 'wikidiff_do_diff' ) ) {
-				dl('php_wikidiff.so');
-			}
-			return $wgContLang->unsegementForDiff( wikidiff_do_diff( $otext, $ntext, 2 ) ) .
-			$this->debug( 'wikidiff1' );
-		}
-
-		if ( $wgExternalDiffEngine == 'wikidiff2' ) {
-			# Better external diff engine, the 2 may some day be dropped
-			# This one does the escaping and segmenting itself
-			if ( !function_exists( 'wikidiff2_do_diff' ) ) {
-				wfProfileIn( __METHOD__ . "-dl" );
-				@dl('php_wikidiff2.so');
-				wfProfileOut( __METHOD__ . "-dl" );
-			}
-			if ( function_exists( 'wikidiff2_do_diff' ) ) {
-				wfProfileIn( 'wikidiff2_do_diff' );
-				$text = wikidiff2_do_diff( $otext, $ntext, 2 );
-				$text .= $this->debug( 'wikidiff2' );
-				wfProfileOut( 'wikidiff2_do_diff' );
-				return $text;
-			}
-		}
-		if ( $wgExternalDiffEngine != 'wikidiff3' && $wgExternalDiffEngine !== false ) {
-			# Diff via the shell
-			global $wgTmpDirectory;
-			$tempName1 = tempnam( $wgTmpDirectory, 'diff_' );
-			$tempName2 = tempnam( $wgTmpDirectory, 'diff_' );
-
-			$tempFile1 = fopen( $tempName1, "w" );
-			if ( !$tempFile1 ) {
-				wfProfileOut( __METHOD__ );
-				return false;
-			}
-			$tempFile2 = fopen( $tempName2, "w" );
-			if ( !$tempFile2 ) {
-				wfProfileOut( __METHOD__ );
-				return false;
-			}
-			fwrite( $tempFile1, $otext );
-			fwrite( $tempFile2, $ntext );
-			fclose( $tempFile1 );
-			fclose( $tempFile2 );
-			$cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
-			wfProfileIn( __METHOD__ . "-shellexec" );
-			$difftext = wfShellExec( $cmd );
-			$difftext .= $this->debug( "external $wgExternalDiffEngine" );
-			wfProfileOut( __METHOD__ . "-shellexec" );
-			unlink( $tempName1 );
-			unlink( $tempName2 );
-			return $difftext;
-		}
-
-		# Native PHP diff
-		$ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) );
-		$nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) );
-		$diffs = new Diff( $ota, $nta );
-		$formatter = new TableDiffFormatter();
-		return $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) ) .
-		$this->debug();
-	}
-
-	/**
-	 * Generate a debug comment indicating diff generating time,
-	 * server node, and generator backend.
-	 */
-	protected function debug( $generator="internal" ) {
-		global $wgShowHostnames;
-		$data = array( $generator );
-		if( $wgShowHostnames ) {
-			$data[] = wfHostname();
-		}
-		$data[] = wfTimestamp( TS_DB );
-		return "\n";
-	}
-
-	/**
-	 * Replace line numbers with the text in the user's language
-	 */
-	function localiseLineNumbers( $text ) {
-		return preg_replace_callback( '//',
-		array( &$this, 'localiseLineNumbersCb' ), $text );
-	}
-
-	function localiseLineNumbersCb( $matches ) {
-		global $wgLang;
-		return wfMsgExt( 'lineno', array (), $wgLang->formatNum( $matches[1] ) );
-	}
-
-
-	/**
-	 * If there are revisions between the ones being compared, return a note saying so.
-	 */
-	function getMultiNotice() {
-		if ( !is_object($this->mOldRev) || !is_object($this->mNewRev) )
-		return '';
-
-		if( !$this->mOldPage->equals( $this->mNewPage ) ) {
-			// Comparing two different pages? Count would be meaningless.
-			return '';
-		}
-
-		$oldid = $this->mOldRev->getId();
-		$newid = $this->mNewRev->getId();
-		if ( $oldid > $newid ) {
-			$tmp = $oldid; $oldid = $newid; $newid = $tmp;
-		}
-
-		$n = $this->mTitle->countRevisionsBetween( $oldid, $newid );
-		if ( !$n )
-		return '';
-
-		return wfMsgExt( 'diff-multi', array( 'parseinline' ), $n );
-	}
-
-
-	/**
-	 * Add the header to a diff body
-	 */
-	static function addHeader( $diff, $otitle, $ntitle, $multi = '' ) {
-		$header = "
-		
-		-		-		-		-		
-		
-		
-		
-		";
-
-		if ( $multi != '' )
-		$header .= "";
-
-		return $header . $diff . "





{$otitle}{$ntitle}
{$multi}
";
-	}
-
-	/**
-	 * Use specified text instead of loading from the database
-	 */
-	function setText( $oldText, $newText ) {
-		$this->mOldtext = $oldText;
-		$this->mNewtext = $newText;
-		$this->mTextLoaded = 2;
-		$this->mRevisionsLoaded = true;
-	}
-
-	/**
-	 * Load revision metadata for the specified articles. If newid is 0, then compare
-	 * the old article in oldid to the current article; if oldid is 0, then
-	 * compare the current article to the immediately previous one (ignoring the
-	 * value of newid).
-	 *
-	 * If oldid is false, leave the corresponding revision object set
-	 * to false. This is impossible via ordinary user input, and is provided for
-	 * API convenience.
-	 */
-	function loadRevisionData() {
-		global $wgLang, $wgUser;
-		if ( $this->mRevisionsLoaded ) {
-			return true;
-		} else {
-			// Whether it succeeds or fails, we don't want to try again
-			$this->mRevisionsLoaded = true;
-		}
-
-		// Load the new revision object
-		$this->mNewRev = $this->mNewid
-			? Revision::newFromId( $this->mNewid )
-			: Revision::newFromTitle( $this->mTitle );
-		if( !$this->mNewRev instanceof Revision )
-			return false;
-
-		// Update the new revision ID in case it was 0 (makes life easier doing UI stuff)
-		$this->mNewid = $this->mNewRev->getId();
-
-		// Check if page is editable
-		$editable = $this->mNewRev->getTitle()->userCan( 'edit' );
-
-		// Set assorted variables
-		$timestamp = $wgLang->timeanddate( $this->mNewRev->getTimestamp(), true );
-		$this->mNewPage = $this->mNewRev->getTitle();
-		if( $this->mNewRev->isCurrent() ) {
-			$newLink = $this->mNewPage->escapeLocalUrl( 'oldid=' . $this->mNewid );
-			$this->mPagetitle = wfMsgHTML( 'currentrev-asof', $timestamp );
-			$newEdit = $this->mNewPage->escapeLocalUrl( 'action=edit' );
-
-			$this->mNewtitle = "{$this->mPagetitle}";
-			$this->mNewtitle .= " (" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . ")";
-
-		} else {
-			$newLink = $this->mNewPage->escapeLocalUrl( 'oldid=' . $this->mNewid );
-			$newEdit = $this->mNewPage->escapeLocalUrl( 'action=edit&oldid=' . $this->mNewid );
-			$this->mPagetitle = wfMsgHTML( 'revisionasof', $timestamp );
-
-			$this->mNewtitle = "{$this->mPagetitle}";
-			$this->mNewtitle .= " (" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . ")";
-		}
-		if ( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
-			$this->mNewtitle = "{$this->mPagetitle}";
-		} else if ( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
-			$this->mNewtitle = ''.$this->mNewtitle.'';
-		}
-
-		// Load the old revision object
-		$this->mOldRev = false;
-		if( $this->mOldid ) {
-			$this->mOldRev = Revision::newFromId( $this->mOldid );
-		} elseif ( $this->mOldid === 0 ) {
-			$rev = $this->mNewRev->getPrevious();
-			if( $rev ) {
-				$this->mOldid = $rev->getId();
-				$this->mOldRev = $rev;
-			} else {
-				// No previous revision; mark to show as first-version only.
-				$this->mOldid = false;
-				$this->mOldRev = false;
-			}
-		}/* elseif ( $this->mOldid === false ) leave mOldRev false; */
-
-		if( is_null( $this->mOldRev ) ) {
-			return false;
-		}
-
-		if ( $this->mOldRev ) {
-			$this->mOldPage = $this->mOldRev->getTitle();
-
-			$t = $wgLang->timeanddate( $this->mOldRev->getTimestamp(), true );
-			$oldLink = $this->mOldPage->escapeLocalUrl( 'oldid=' . $this->mOldid );
-			$oldEdit = $this->mOldPage->escapeLocalUrl( 'action=edit&oldid=' . $this->mOldid );
-			$this->mOldPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $t ) );
-
-			$this->mOldtitle = "{$this->mOldPagetitle}"
-			. " (" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . ")";
-			// Add an "undo" link
-			$newUndo = $this->mNewPage->escapeLocalUrl( 'action=edit&undoafter=' . $this->mOldid . '&undo=' . $this->mNewid);
-			$htmlLink = htmlspecialchars( wfMsg( 'editundo' ) );
-			$htmlTitle = $wgUser->getSkin()->tooltip( 'undo' );
-			if( $editable && !$this->mOldRev->isDeleted( Revision::DELETED_TEXT ) && !$this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
-				$this->mNewtitle .= " (" . $htmlLink . ")";
-			}
-
-			if( !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
-				$this->mOldtitle = '' . $this->mOldPagetitle . '';
-			} else if( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
-				$this->mOldtitle = '' . $this->mOldtitle . '';
-			}
-		}
-
-		return true;
-	}
-
-	/**
-	 * Load the text of the revisions, as well as revision data.
-	 */
-	function loadText() {
-		if ( $this->mTextLoaded == 2 ) {
-			return true;
-		} else {
-			// Whether it succeeds or fails, we don't want to try again
-			$this->mTextLoaded = 2;
-		}
-
-		if ( !$this->loadRevisionData() ) {
-			return false;
-		}
-		if ( $this->mOldRev ) {
-			$this->mOldtext = $this->mOldRev->getText( Revision::FOR_THIS_USER );
-			if ( $this->mOldtext === false ) {
-				return false;
-			}
-		}
-		if ( $this->mNewRev ) {
-			$this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
-			if ( $this->mNewtext === false ) {
-				return false;
-			}
-		}
-		return true;
-	}
-
-	/**
-	 * Load the text of the new revision, not the old one
-	 */
-	function loadNewText() {
-		if ( $this->mTextLoaded >= 1 ) {
-			return true;
-		} else {
-			$this->mTextLoaded = 1;
-		}
-		if ( !$this->loadRevisionData() ) {
-			return false;
-		}
-		$this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
-		return true;
-	}
-
-
-}
-
 // A PHP diff engine for phpwiki. (Taken from phpwiki-1.3.3)
 //
 // Copyright (C) 2000, 2001 Geoffrey T. Dairiki 
diff --git a/includes/diff/DifferenceInterface.php b/includes/diff/DifferenceInterface.php
new file mode 100644
index 00000000..d7d36799
--- /dev/null
+++ b/includes/diff/DifferenceInterface.php
@@ -0,0 +1,1021 @@
+mTitle = $titleObj;
+		} else {
+			global $wgTitle;
+			$this->mTitle = $wgTitle;
+		}
+		wfDebug("DifferenceEngine old '$old' new '$new' rcid '$rcid'\n");
+
+		if ( 'prev' === $new ) {
+			# Show diff between revision $old and the previous one.
+			# Get previous one from DB.
+			$this->mNewid = intval($old);
+			$this->mOldid = $this->mTitle->getPreviousRevisionID( $this->mNewid );
+		} elseif ( 'next' === $new ) {
+			# Show diff between revision $old and the next one.
+			# Get next one from DB.
+			$this->mOldid = intval($old);
+			$this->mNewid = $this->mTitle->getNextRevisionID( $this->mOldid );
+			if ( false === $this->mNewid ) {
+				# if no result, NewId points to the newest old revision. The only newer
+				# revision is cur, which is "0".
+				$this->mNewid = 0;
+			}
+		} else {
+			$this->mOldid = intval($old);
+			$this->mNewid = intval($new);
+			wfRunHooks( 'NewDifferenceEngine', array(&$titleObj, &$this->mOldid, &$this->mNewid, $old, $new) ); 
+		}
+		$this->mRcidMarkPatrolled = intval($rcid);  # force it to be an integer
+		$this->mRefreshCache = $refreshCache;
+		$this->unhide = $unhide;
+	}
+
+	function setReducedLineNumbers( $value = true ) {
+		$this->mReducedLineNumbers = $value;
+	}
+
+	function getTitle() {
+		return $this->mTitle;
+	}
+	
+	function wasCacheHit() {
+		return $this->mCacheHit;
+	}
+	
+	function getOldid() {
+		return $this->mOldid;
+	}
+	
+	function getNewid() {
+		return $this->mNewid;
+	}
+
+	function showDiffPage( $diffOnly = false ) {
+		global $wgUser, $wgOut, $wgUseExternalEditor, $wgUseRCPatrol;
+		wfProfileIn( __METHOD__ );
+
+
+		# If external diffs are enabled both globally and for the user,
+		# we'll use the application/x-external-editor interface to call
+		# an external diff tool like kompare, kdiff3, etc.
+		if($wgUseExternalEditor && $wgUser->getOption('externaldiff')) {
+			global $wgInputEncoding,$wgServer,$wgScript,$wgLang;
+			$wgOut->disable();
+			header ( "Content-type: application/x-external-editor; charset=".$wgInputEncoding );
+			$url1=$this->mTitle->getFullURL( array(
+				'action' => 'raw',
+				'oldid' => $this->mOldid
+			) );
+			$url2=$this->mTitle->getFullURL( array(
+				'action' => 'raw',
+				'oldid' => $this->mNewid
+			) );
+			$special=$wgLang->getNsText(NS_SPECIAL);
+			$control=<<setArticleFlag( false );
+		if ( !$this->loadRevisionData() ) {
+			$t = $this->mTitle->getPrefixedText();
+			$d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
+			$wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
+			$wgOut->addWikiMsg( 'missing-article', "$t", $d );
+			wfProfileOut( __METHOD__ );
+			return;
+		}
+
+		wfRunHooks( 'DiffViewHeader', array( $this, $this->mOldRev, $this->mNewRev ) );
+
+		if ( $this->mNewRev->isCurrent() ) {
+			$wgOut->setArticleFlag( true );
+		}
+
+		# mOldid is false if the difference engine is called with a "vague" query for
+		# a diff between a version V and its previous version V' AND the version V
+		# is the first version of that article. In that case, V' does not exist.
+		if ( $this->mOldid === false ) {
+			$this->showFirstRevision();
+			$this->renderNewRevision();  // should we respect $diffOnly here or not?
+			wfProfileOut( __METHOD__ );
+			return;
+		}
+
+		$wgOut->suppressQuickbar();
+
+		$oldTitle = $this->mOldPage->getPrefixedText();
+		$newTitle = $this->mNewPage->getPrefixedText();
+		if( $oldTitle == $newTitle ) {
+			$wgOut->setPageTitle( $newTitle );
+		} else {
+			$wgOut->setPageTitle( $oldTitle . ', ' . $newTitle );
+		}
+		$wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
+		$wgOut->setRobotPolicy( 'noindex,nofollow' );
+
+		if ( !$this->mOldPage->userCanRead() || !$this->mNewPage->userCanRead() ) {
+			$wgOut->loginToUse();
+			$wgOut->output();
+			$wgOut->disable();
+			wfProfileOut( __METHOD__ );
+			return;
+		}
+
+		$sk = $wgUser->getSkin();
+
+		// Check if page is editable
+		$editable = $this->mNewRev->getTitle()->userCan( 'edit' );
+		if ( $editable && $this->mNewRev->isCurrent() && $wgUser->isAllowed( 'rollback' ) ) {
+			$rollback = '   ' . $sk->generateRollback( $this->mNewRev );
+		} else {
+			$rollback = '';
+		}
+
+		// Prepare a change patrol link, if applicable
+		if( $wgUseRCPatrol && $this->mTitle->userCan('patrol') ) {
+			// If we've been given an explicit change identifier, use it; saves time
+			if( $this->mRcidMarkPatrolled ) {
+				$rcid = $this->mRcidMarkPatrolled;
+				$rc = RecentChange::newFromId( $rcid );
+				// Already patrolled?
+				$rcid = is_object($rc) && !$rc->getAttribute('rc_patrolled') ? $rcid : 0;
+			} else {
+				// Look for an unpatrolled change corresponding to this diff
+				$db = wfGetDB( DB_SLAVE );
+				$change = RecentChange::newFromConds(
+					array(
+					// Redundant user,timestamp condition so we can use the existing index
+						'rc_user_text'  => $this->mNewRev->getRawUserText(),
+						'rc_timestamp'  => $db->timestamp( $this->mNewRev->getTimestamp() ),
+						'rc_this_oldid' => $this->mNewid,
+						'rc_last_oldid' => $this->mOldid,
+						'rc_patrolled'  => 0
+					),
+					__METHOD__
+				);
+				if( $change instanceof RecentChange ) {
+					$rcid = $change->mAttribs['rc_id'];
+					$this->mRcidMarkPatrolled = $rcid;
+				} else {
+					// None found
+					$rcid = 0;
+				}
+			}
+			// Build the link
+			if( $rcid ) {
+				$patrol = ' [' . $sk->link(
+					$this->mTitle, 
+					wfMsgHtml( 'markaspatrolleddiff' ),
+					array(),
+					array(
+						'action' => 'markpatrolled',
+						'rcid' => $rcid
+					),
+					array(
+						'known',
+						'noclasses'
+					)
+				) . ']';
+			} else {
+				$patrol = '';
+			}
+		} else {
+			$patrol = '';
+		}
+
+		# Carry over 'diffonly' param via navigation links
+		if( $diffOnly != $wgUser->getBoolOption('diffonly') ) {
+			$query['diffonly'] = $diffOnly;
+		}
+
+		# Make "previous revision link"
+		$query['diff'] = 'prev';
+		$query['oldid'] = $this->mOldid;
+		# Cascade unhide param in links for easy deletion browsing
+		if( $this->unhide ) {
+			$query['unhide'] = 1;
+		}
+		$prevlink = $sk->link(
+			$this->mTitle,
+			wfMsgHtml( 'previousdiff' ),
+			array(
+				'id' => 'differences-prevlink'
+			),
+			$query,
+			array(
+				'known',
+				'noclasses'
+			)
+		);
+
+		# Make "next revision link"
+		$query['diff'] = 'next';
+		$query['oldid'] = $this->mNewid;
+		# Skip next link on the top revision
+		if( $this->mNewRev->isCurrent() ) {
+			$nextlink = ' ';
+		} else {
+			$nextlink = $sk->link(
+				$this->mTitle,
+				wfMsgHtml( 'nextdiff' ),
+				array(
+					'id' => 'differences-nextlink'
+				),
+				$query,
+				array(
+					'known',
+					'noclasses'
+				)
+			);
+		}
+
+		$oldminor = '';
+		$newminor = '';
+
+		if( $this->mOldRev->isMinor() ) {
+			$oldminor = ChangesList::flag( 'minor' );
+		}
+		if( $this->mNewRev->isMinor() ) {
+			$newminor = ChangesList::flag( 'minor' );
+		}
+
+		# Handle RevisionDelete links...
+		$ldel = $this->revisionDeleteLink( $this->mOldRev );
+		$rdel = $this->revisionDeleteLink( $this->mNewRev );
+
+		$oldHeader = '
'.$this->mOldtitle.'
' .
+			'
' .
+				$sk->revUserTools( $this->mOldRev, !$this->unhide ).'
' .
+			'
' . $oldminor .
+				$sk->revComment( $this->mOldRev, !$diffOnly, !$this->unhide ).$ldel.'
' .
+			'
' . $prevlink .'
';
+		$newHeader = '
'.$this->mNewtitle.'
' .
+			'
' . $sk->revUserTools( $this->mNewRev, !$this->unhide ) .
+				" $rollback
" .
+			'
' . $newminor .
+				$sk->revComment( $this->mNewRev, !$diffOnly, !$this->unhide ).$rdel.'
' .
+			'
' . $nextlink . $patrol . '
';
+
+		# Check if this user can see the revisions
+		$allowed = $this->mOldRev->userCan(Revision::DELETED_TEXT)
+			&& $this->mNewRev->userCan(Revision::DELETED_TEXT);
+		# Check if one of the revisions is deleted/suppressed
+		$deleted = $suppressed = false;
+		if( $this->mOldRev->isDeleted(Revision::DELETED_TEXT) ) {
+			$deleted = true; // old revisions text is hidden
+			if( $this->mOldRev->isDeleted(Revision::DELETED_RESTRICTED) )
+				$suppressed = true; // also suppressed
+		}
+		if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
+			$deleted = true; // new revisions text is hidden
+			if( $this->mNewRev->isDeleted(Revision::DELETED_RESTRICTED) )
+				$suppressed = true; // also suppressed
+		}
+		# If the diff cannot be shown due to a deleted revision, then output
+		# the diff header and links to unhide (if available)...
+		if( $deleted && (!$this->unhide || !$allowed) ) {
+			$this->showDiffStyle();
+			$multi = $this->getMultiNotice();
+			$wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) );
+			if( !$allowed ) {
+				$msg = $suppressed ? 'rev-suppressed-no-diff' : 'rev-deleted-no-diff';
+				# Give explanation for why revision is not visible
+				$wgOut->wrapWikiMsg( "
\n$1
\n",
+					array( $msg ) );
+			} else {
+				# Give explanation and add a link to view the diff...
+				$link = $this->mTitle->getFullUrl( array(
+					'diff' => $this->mNewid,
+					'oldid' => $this->mOldid,
+					'unhide' => 1
+				) );
+				$msg = $suppressed ? 'rev-suppressed-unhide-diff' : 'rev-deleted-unhide-diff';
+				$wgOut->wrapWikiMsg( "
\n$1
\n", array( $msg, $link ) );
+			}
+		# Otherwise, output a regular diff...
+		} else {
+			# Add deletion notice if the user is viewing deleted content
+			$notice = '';
+			if( $deleted ) {
+				$msg = $suppressed ? 'rev-suppressed-diff-view' : 'rev-deleted-diff-view';
+				$notice = "
\n".wfMsgExt($msg,'parseinline')."
\n";
+			}
+			$this->showDiff( $oldHeader, $newHeader, $notice );
+			if( !$diffOnly ) {
+				$this->renderNewRevision();
+			}
+		}
+		wfProfileOut( __METHOD__ );
+	}
+	
+	protected function revisionDeleteLink( $rev ) {
+		global $wgUser;
+		$link = '';
+		$canHide = $wgUser->isAllowed( 'deleterevision' );
+		// Show del/undel link if:
+		// (a) the user can delete revisions, or
+		// (b) the user can view deleted revision *and* this one is deleted
+		if( $canHide || ($rev->getVisibility() && $wgUser->isAllowed( 'deletedhistory' )) ) {
+			$sk = $wgUser->getSkin();
+			if( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
+				$link = $sk->revDeleteLinkDisabled( $canHide ); // revision was hidden from sysops
+			} else {
+				$query = array(
+					'type' 	 => 'revision',
+					'target' => $rev->mTitle->getPrefixedDbkey(),
+					'ids' 	 => $rev->getId()
+				);
+				$link = $sk->revDeleteLink( $query,
+					$rev->isDeleted( Revision::DELETED_RESTRICTED ), $canHide );
+			}
+			$link = '   ' . $link . ' ';
+		}
+		return $link;
+	}
+
+	/**
+	 * Show the new revision of the page.
+	 */
+	function renderNewRevision() {
+		global $wgOut, $wgUser;
+		wfProfileIn( __METHOD__ );
+
+		$wgOut->addHTML( "
{$this->mPagetitle}
\n" );
+		# Add deleted rev tag if needed
+		if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
+			$wgOut->wrapWikiMsg( "
\n$1
\n", 'rev-deleted-text-permission' );
+		} else if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
+			$wgOut->wrapWikiMsg( "
\n$1
\n", 'rev-deleted-text-view' );
+		}
+
+		if( !$this->mNewRev->isCurrent() ) {
+			$oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false );
+		}
+
+		$this->loadNewText();
+		if( is_object( $this->mNewRev ) ) {
+			$wgOut->setRevisionId( $this->mNewRev->getId() );
+		}
+
+		if( $this->mTitle->isCssJsSubpage() || $this->mTitle->isCssOrJsPage() ) {
+			// Stolen from Article::view --AG 2007-10-11
+			// Give hooks a chance to customise the output
+			if( wfRunHooks( 'ShowRawCssJs', array( $this->mNewtext, $this->mTitle, $wgOut ) ) ) {
+				// Wrap the whole lot in a 
 and don't parse
+				$m = array();
+				preg_match( '!\.(css|js)$!u', $this->mTitle->getText(), $m );
+				$wgOut->addHTML( "
\n" );
+				$wgOut->addHTML( htmlspecialchars( $this->mNewtext ) );
+				$wgOut->addHTML( "\n
\n" );
+			}
+		} else {
+			$wgOut->addWikiTextTidy( $this->mNewtext );
+		}
+
+		if( is_object( $this->mNewRev ) && !$this->mNewRev->isCurrent() ) {
+			$wgOut->parserOptions()->setEditSection( $oldEditSectionSetting );
+		}
+		# Add redundant patrol link on bottom...
+		if( $this->mRcidMarkPatrolled && $this->mTitle->quickUserCan('patrol') ) {
+			$sk = $wgUser->getSkin();
+			$wgOut->addHTML(
+				"
[" . $sk->link(
+					$this->mTitle,
+					wfMsgHtml( 'markaspatrolleddiff' ),
+					array(),
+					array(
+						'action' => 'markpatrolled',
+						'rcid' => $this->mRcidMarkPatrolled
+					)
+				) . ']
'
+			 );
+		}
+
+		wfProfileOut( __METHOD__ );
+	}
+
+	/**
+	 * Show the first revision of an article. Uses normal diff headers in
+	 * contrast to normal "old revision" display style.
+	 */
+	function showFirstRevision() {
+		global $wgOut, $wgUser;
+		wfProfileIn( __METHOD__ );
+
+		# Get article text from the DB
+		#
+		if ( ! $this->loadNewText() ) {
+			$t = $this->mTitle->getPrefixedText();
+			$d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
+			$wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
+			$wgOut->addWikiMsg( 'missing-article', "$t", $d );
+			wfProfileOut( __METHOD__ );
+			return;
+		}
+		if ( $this->mNewRev->isCurrent() ) {
+			$wgOut->setArticleFlag( true );
+		}
+
+		# Check if user is allowed to look at this page. If not, bail out.
+		#
+		if ( !$this->mTitle->userCanRead() ) {
+			$wgOut->loginToUse();
+			$wgOut->output();
+			wfProfileOut( __METHOD__ );
+			throw new MWException("Permission Error: you do not have access to view this page");
+		}
+
+		# Prepare the header box
+		#
+		$sk = $wgUser->getSkin();
+
+		$next = $this->mTitle->getNextRevisionID( $this->mNewid );
+		if( !$next ) {
+			$nextlink = '';
+		} else {
+			$nextlink = '
' . $sk->link(
+				$this->mTitle,
+				wfMsgHtml( 'nextdiff' ),
+				array(
+					'id' => 'differences-nextlink'
+				),
+				array(
+					'diff' => 'next',
+					'oldid' => $this->mNewid,
+				),
+				array(
+					'known',
+					'noclasses'
+				)
+			);
+		}
+		$header = "
" .
+			$sk->revUserTools( $this->mNewRev ) . "
" . $sk->revComment( $this->mNewRev ) . $nextlink . "
\n";
+
+		$wgOut->addHTML( $header );
+
+		$wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
+		$wgOut->setRobotPolicy( 'noindex,nofollow' );
+
+		wfProfileOut( __METHOD__ );
+	}
+
+	/**
+	 * Get the diff text, send it to $wgOut
+	 * Returns false if the diff could not be generated, otherwise returns true
+	 */
+	function showDiff( $otitle, $ntitle, $notice = '' ) {
+		global $wgOut;
+		$diff = $this->getDiff( $otitle, $ntitle, $notice );
+		if ( $diff === false ) {
+			$wgOut->addWikiMsg( 'missing-article', "(fixme, bug)", '' );
+			return false;
+		} else {
+			$this->showDiffStyle();
+			$wgOut->addHTML( $diff );
+			return true;
+		}
+	}
+
+	/**
+	 * Add style sheets and supporting JS for diff display.
+	 */
+	function showDiffStyle() {
+		global $wgStylePath, $wgStyleVersion, $wgOut;
+		$wgOut->addStyle( 'common/diff.css' );
+
+		// JS is needed to detect old versions of Mozilla to work around an annoyance bug.
+		$wgOut->addScript( "" );
+	}
+
+	/**
+	 * Get complete diff table, including header
+	 *
+	 * @param Title $otitle Old title
+	 * @param Title $ntitle New title
+	 * @param string $notice HTML between diff header and body
+	 * @return mixed
+	 */
+	function getDiff( $otitle, $ntitle, $notice = '' ) {
+		$body = $this->getDiffBody();
+		if ( $body === false ) {
+			return false;
+		} else {
+			$multi = $this->getMultiNotice();
+			return $this->addHeader( $body, $otitle, $ntitle, $multi, $notice );
+		}
+	}
+
+	/**
+	 * Get the diff table body, without header
+	 *
+	 * @return mixed
+	 */
+	function getDiffBody() {
+		global $wgMemc;
+		wfProfileIn( __METHOD__ );
+		$this->mCacheHit = true;
+		// Check if the diff should be hidden from this user
+		if ( !$this->loadRevisionData() )
+			return '';
+		if ( $this->mOldRev && !$this->mOldRev->userCan(Revision::DELETED_TEXT) ) {
+			return '';
+		} else if ( $this->mNewRev && !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
+			return '';
+		} else if ( $this->mOldRev && $this->mNewRev && $this->mOldRev->getID() == $this->mNewRev->getID() ) {
+			return '';
+		}
+		// Cacheable?
+		$key = false;
+		if ( $this->mOldid && $this->mNewid ) {
+			$key = wfMemcKey( 'diff', 'version', MW_DIFF_VERSION, 'oldid', $this->mOldid, 'newid', $this->mNewid );
+			// Try cache
+			if ( !$this->mRefreshCache ) {
+				$difftext = $wgMemc->get( $key );
+				if ( $difftext ) {
+					wfIncrStats( 'diff_cache_hit' );
+					$difftext = $this->localiseLineNumbers( $difftext );
+					$difftext .= "\n\n";
+					wfProfileOut( __METHOD__ );
+					return $difftext;
+				}
+			} // don't try to load but save the result
+		}
+		$this->mCacheHit = false;
+
+		// Loadtext is permission safe, this just clears out the diff
+		if ( !$this->loadText() ) {
+			wfProfileOut( __METHOD__ );
+			return false;
+		}
+
+		$difftext = $this->generateDiffBody( $this->mOldtext, $this->mNewtext );
+
+		// Save to cache for 7 days
+		if ( !wfRunHooks( 'AbortDiffCache', array( &$this ) ) ) {
+			wfIncrStats( 'diff_uncacheable' );
+		} else if ( $key !== false && $difftext !== false ) {
+			wfIncrStats( 'diff_cache_miss' );
+			$wgMemc->set( $key, $difftext, 7*86400 );
+		} else {
+			wfIncrStats( 'diff_uncacheable' );
+		}
+		// Replace line numbers with the text in the user's language
+		if ( $difftext !== false ) {
+			$difftext = $this->localiseLineNumbers( $difftext );
+		}
+		wfProfileOut( __METHOD__ );
+		return $difftext;
+	}
+
+	/**
+	 * Make sure the proper modules are loaded before we try to
+	 * make the diff
+	 */
+	private function initDiffEngines() {
+		global $wgExternalDiffEngine;
+		if ( $wgExternalDiffEngine == 'wikidiff' && !function_exists( 'wikidiff_do_diff' ) ) {
+			wfProfileIn( __METHOD__ . '-php_wikidiff.so' );
+			wfSuppressWarnings();
+			dl( 'php_wikidiff.so' );
+			wfRestoreWarnings();
+			wfProfileOut( __METHOD__ . '-php_wikidiff.so' );
+		}
+		else if ( $wgExternalDiffEngine == 'wikidiff2' && !function_exists( 'wikidiff2_do_diff' ) ) {
+			wfProfileIn( __METHOD__ . '-php_wikidiff2.so' );
+			wfSuppressWarnings();
+			dl( 'php_wikidiff2.so' );
+			wfRestoreWarnings();
+			wfProfileOut( __METHOD__ . '-php_wikidiff2.so' );
+		}
+	}
+
+	/**
+	 * Generate a diff, no caching
+	 * $otext and $ntext must be already segmented
+	 */
+	function generateDiffBody( $otext, $ntext ) {
+		global $wgExternalDiffEngine, $wgContLang;
+
+		$otext = str_replace( "\r\n", "\n", $otext );
+		$ntext = str_replace( "\r\n", "\n", $ntext );
+
+		$this->initDiffEngines();
+
+		if ( $wgExternalDiffEngine == 'wikidiff' && function_exists( 'wikidiff_do_diff' ) ) {
+			# For historical reasons, external diff engine expects
+			# input text to be HTML-escaped already
+			$otext = htmlspecialchars ( $wgContLang->segmentForDiff( $otext ) );
+			$ntext = htmlspecialchars ( $wgContLang->segmentForDiff( $ntext ) );
+			return $wgContLang->unsegementForDiff( wikidiff_do_diff( $otext, $ntext, 2 ) ) .
+			$this->debug( 'wikidiff1' );
+		}
+
+		if ( $wgExternalDiffEngine == 'wikidiff2' && function_exists( 'wikidiff2_do_diff' ) ) {
+			# Better external diff engine, the 2 may some day be dropped
+			# This one does the escaping and segmenting itself
+			wfProfileIn( 'wikidiff2_do_diff' );
+			$text = wikidiff2_do_diff( $otext, $ntext, 2 );
+			$text .= $this->debug( 'wikidiff2' );
+			wfProfileOut( 'wikidiff2_do_diff' );
+			return $text;
+		}
+		if ( $wgExternalDiffEngine != 'wikidiff3' && $wgExternalDiffEngine !== false ) {
+			# Diff via the shell
+			global $wgTmpDirectory;
+			$tempName1 = tempnam( $wgTmpDirectory, 'diff_' );
+			$tempName2 = tempnam( $wgTmpDirectory, 'diff_' );
+
+			$tempFile1 = fopen( $tempName1, "w" );
+			if ( !$tempFile1 ) {
+				wfProfileOut( __METHOD__ );
+				return false;
+			}
+			$tempFile2 = fopen( $tempName2, "w" );
+			if ( !$tempFile2 ) {
+				wfProfileOut( __METHOD__ );
+				return false;
+			}
+			fwrite( $tempFile1, $otext );
+			fwrite( $tempFile2, $ntext );
+			fclose( $tempFile1 );
+			fclose( $tempFile2 );
+			$cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
+			wfProfileIn( __METHOD__ . "-shellexec" );
+			$difftext = wfShellExec( $cmd );
+			$difftext .= $this->debug( "external $wgExternalDiffEngine" );
+			wfProfileOut( __METHOD__ . "-shellexec" );
+			unlink( $tempName1 );
+			unlink( $tempName2 );
+			return $difftext;
+		}
+
+		# Native PHP diff
+		$ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) );
+		$nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) );
+		$diffs = new Diff( $ota, $nta );
+		$formatter = new TableDiffFormatter();
+		return $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) ) .
+		$this->debug();
+	}
+
+	/**
+	 * Generate a debug comment indicating diff generating time,
+	 * server node, and generator backend.
+	 */
+	protected function debug( $generator="internal" ) {
+		global $wgShowHostnames;
+		if ( !$this->enableDebugComment ) {
+			return '';
+		}
+		$data = array( $generator );
+		if( $wgShowHostnames ) {
+			$data[] = wfHostname();
+		}
+		$data[] = wfTimestamp( TS_DB );
+		return "\n";
+	}
+
+	/**
+	 * Replace line numbers with the text in the user's language
+	 */
+	function localiseLineNumbers( $text ) {
+		return preg_replace_callback( '//',
+		array( &$this, 'localiseLineNumbersCb' ), $text );
+	}
+
+	function localiseLineNumbersCb( $matches ) {
+		global $wgLang;
+		if ( $matches[1] === '1' && $this->mReducedLineNumbers ) return '';
+		return wfMsgExt( 'lineno', 'escape', $wgLang->formatNum( $matches[1] ) );
+	}
+
+
+	/**
+	 * If there are revisions between the ones being compared, return a note saying so.
+	 */
+	function getMultiNotice() {
+		if ( !is_object($this->mOldRev) || !is_object($this->mNewRev) )
+		return '';
+
+		if( !$this->mOldPage->equals( $this->mNewPage ) ) {
+			// Comparing two different pages? Count would be meaningless.
+			return '';
+		}
+
+		$oldid = $this->mOldRev->getId();
+		$newid = $this->mNewRev->getId();
+		if ( $oldid > $newid ) {
+			$tmp = $oldid; $oldid = $newid; $newid = $tmp;
+		}
+
+		$n = $this->mTitle->countRevisionsBetween( $oldid, $newid );
+		if ( !$n )
+		return '';
+
+		return wfMsgExt( 'diff-multi', array( 'parseinline' ), $n );
+	}
+
+
+	/**
+	 * Add the header to a diff body
+	 */
+	static function addHeader( $diff, $otitle, $ntitle, $multi = '', $notice = '' ) {
+		$header = "";
+		if( $diff ) { // Safari/Chrome show broken output if cols not used
+			$header .= "
+			+			+			+			";
+			$colspan = 2;
+			$multiColspan = 4;
+		} else {
+			$colspan = 1;
+			$multiColspan = 2;
+		}
+		$header .= "
+		
+		
+		
+		";
+
+		if ( $multi != '' ) {
+			$header .= "";
+		}
+		if ( $notice != '' ) {
+			$header .= "";
+		}
+
+		return $header . $diff . "




{$otitle}{$ntitle}
{$multi}
{$notice}
";
+	}
+
+	/**
+	 * Use specified text instead of loading from the database
+	 */
+	function setText( $oldText, $newText ) {
+		$this->mOldtext = $oldText;
+		$this->mNewtext = $newText;
+		$this->mTextLoaded = 2;
+		$this->mRevisionsLoaded = true;
+	}
+
+	/**
+	 * Load revision metadata for the specified articles. If newid is 0, then compare
+	 * the old article in oldid to the current article; if oldid is 0, then
+	 * compare the current article to the immediately previous one (ignoring the
+	 * value of newid).
+	 *
+	 * If oldid is false, leave the corresponding revision object set
+	 * to false. This is impossible via ordinary user input, and is provided for
+	 * API convenience.
+	 */
+	function loadRevisionData() {
+		global $wgLang, $wgUser;
+		if ( $this->mRevisionsLoaded ) {
+			return true;
+		} else {
+			// Whether it succeeds or fails, we don't want to try again
+			$this->mRevisionsLoaded = true;
+		}
+
+		// Load the new revision object
+		$this->mNewRev = $this->mNewid
+			? Revision::newFromId( $this->mNewid )
+			: Revision::newFromTitle( $this->mTitle );
+		if( !$this->mNewRev instanceof Revision )
+			return false;
+
+		// Update the new revision ID in case it was 0 (makes life easier doing UI stuff)
+		$this->mNewid = $this->mNewRev->getId();
+
+		// Check if page is editable
+		$editable = $this->mNewRev->getTitle()->userCan( 'edit' );
+
+		// Set assorted variables
+		$timestamp = $wgLang->timeanddate( $this->mNewRev->getTimestamp(), true );
+		$dateofrev = $wgLang->date( $this->mNewRev->getTimestamp(), true );
+		$timeofrev = $wgLang->time( $this->mNewRev->getTimestamp(), true );
+		$this->mNewPage = $this->mNewRev->getTitle();
+		if( $this->mNewRev->isCurrent() ) {
+			$newLink = $this->mNewPage->escapeLocalUrl( array(
+				'oldid' => $this->mNewid
+			) );
+			$this->mPagetitle = htmlspecialchars( wfMsg(
+				'currentrev-asof',
+				$timestamp,
+				$dateofrev,
+				$timeofrev
+			) );
+			$newEdit = $this->mNewPage->escapeLocalUrl( array(
+				'action' => 'edit'
+			) );
+
+			$this->mNewtitle = "{$this->mPagetitle}";
+			$this->mNewtitle .= " (" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . ")";
+		} else {
+			$newLink = $this->mNewPage->escapeLocalUrl( array(
+				'oldid' => $this->mNewid
+			) );
+			$newEdit = $this->mNewPage->escapeLocalUrl( array(
+				'action' => 'edit',
+				'oldid' => $this->mNewid
+			) );
+			$this->mPagetitle = htmlspecialchars( wfMsg(
+				'revisionasof',
+				$timestamp,
+				$dateofrev,
+				$timeofrev
+			) );
+
+			$this->mNewtitle = "{$this->mPagetitle}";
+			$this->mNewtitle .= " (" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . ")";
+		}
+		if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
+			$this->mNewtitle = "{$this->mPagetitle}";
+		} else if ( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
+			$this->mNewtitle = "{$this->mNewtitle}";
+		}
+
+		// Load the old revision object
+		$this->mOldRev = false;
+		if( $this->mOldid ) {
+			$this->mOldRev = Revision::newFromId( $this->mOldid );
+		} elseif ( $this->mOldid === 0 ) {
+			$rev = $this->mNewRev->getPrevious();
+			if( $rev ) {
+				$this->mOldid = $rev->getId();
+				$this->mOldRev = $rev;
+			} else {
+				// No previous revision; mark to show as first-version only.
+				$this->mOldid = false;
+				$this->mOldRev = false;
+			}
+		}/* elseif ( $this->mOldid === false ) leave mOldRev false; */
+
+		if( is_null( $this->mOldRev ) ) {
+			return false;
+		}
+
+		if ( $this->mOldRev ) {
+			$this->mOldPage = $this->mOldRev->getTitle();
+
+			$t = $wgLang->timeanddate( $this->mOldRev->getTimestamp(), true );
+			$dateofrev = $wgLang->date( $this->mOldRev->getTimestamp(), true );
+			$timeofrev = $wgLang->time( $this->mOldRev->getTimestamp(), true );
+			$oldLink = $this->mOldPage->escapeLocalUrl( array(
+				'oldid' => $this->mOldid
+			) );
+			$oldEdit = $this->mOldPage->escapeLocalUrl( array(
+				'action' => 'edit',
+				'oldid' => $this->mOldid
+			) );
+			$this->mOldPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $t, $dateofrev, $timeofrev ) );
+
+			$this->mOldtitle = "{$this->mOldPagetitle}"
+			. " (" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . ")";
+			// Add an "undo" link
+			$newUndo = $this->mNewPage->escapeLocalUrl( array(
+				'action' => 'edit',
+				'undoafter' => $this->mOldid,
+				'undo' => $this->mNewid
+			) );
+			$htmlLink = htmlspecialchars( wfMsg( 'editundo' ) );
+			$htmlTitle = $wgUser->getSkin()->tooltip( 'undo' );
+			if( $editable && !$this->mOldRev->isDeleted( Revision::DELETED_TEXT ) && !$this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
+				$this->mNewtitle .= " (" . $htmlLink . ")";
+			}
+
+			if( !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
+				$this->mOldtitle = '' . $this->mOldPagetitle . '';
+			} else if( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
+				$this->mOldtitle = '' . $this->mOldtitle . '';
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Load the text of the revisions, as well as revision data.
+	 */
+	function loadText() {
+		if ( $this->mTextLoaded == 2 ) {
+			return true;
+		} else {
+			// Whether it succeeds or fails, we don't want to try again
+			$this->mTextLoaded = 2;
+		}
+
+		if ( !$this->loadRevisionData() ) {
+			return false;
+		}
+		if ( $this->mOldRev ) {
+			$this->mOldtext = $this->mOldRev->getText( Revision::FOR_THIS_USER );
+			if ( $this->mOldtext === false ) {
+				return false;
+			}
+		}
+		if ( $this->mNewRev ) {
+			$this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
+			if ( $this->mNewtext === false ) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * Load the text of the new revision, not the old one
+	 */
+	function loadNewText() {
+		if ( $this->mTextLoaded >= 1 ) {
+			return true;
+		} else {
+			$this->mTextLoaded = 1;
+		}
+		if ( !$this->loadRevisionData() ) {
+			return false;
+		}
+		$this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
+		return true;
+	}
+}
diff --git a/includes/diff/HTMLDiff.php b/includes/diff/HTMLDiff.php
deleted file mode 100644
index df9f4eb8..00000000
--- a/includes/diff/HTMLDiff.php
+++ /dev/null
@@ -1,1009 +0,0 @@
-
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- * or see http://www.gnu.org/
- * 
- * @ingroup DifferenceEngine
- */
-
-/**
- * When detecting the last common parent of two nodes, all results are stored as
- * a LastCommonParentResult.
- */
-class LastCommonParentResult {
-
-	// Parent
-	public $parent;
-
-	// Splitting
-	public $splittingNeeded = false;
-
-	// Depth
-	public $lastCommonParentDepth = -1;
-
-	// Index
-	public $indexInLastCommonParent = -1;
-}
-
-class Modification{
-
-	const NONE = 1;
-	const REMOVED = 2;
-	const ADDED = 4;
-	const CHANGED = 8;
-
-	public $type;
-
-	public $id = -1;
-
-	public $firstOfID = false;
-
-	public $changes;
-
-	function __construct($type) {
-		$this->type = $type;
-	}
-
-	public static function typeToString($type) {
-		switch($type) {
-			case self::NONE: return 'none';
-			case self::REMOVED: return 'removed';
-			case self::ADDED: return 'added';
-			case self::CHANGED: return 'changed';
-		}
-	}
-}
-
-class DomTreeBuilder {
-
-	public $textNodes = array();
-
-	public $bodyNode;
-
-	private $currentParent;
-
-	private $newWord = '';
-
-	protected $bodyStarted = false;
-
-	protected $bodyEnded = false;
-
-	private $whiteSpaceBeforeThis = false;
-
-	private $lastSibling;
-
-	private $notInPre = true;
-
-	function __construct() {
-		$this->bodyNode = $this->currentParent = new BodyNode();
-		$this->lastSibling = new DummyNode();
-	}
-
-	/**
-	 * Must be called manually
-	 */
-	public function endDocument() {
-		$this->endWord();
-		HTMLDiffer::diffDebug( count($this->textNodes) . " text nodes in document.\n" );
-	}
-
-	public function startElement($parser, $name, /*array*/ $attributes) {
-		if (strcasecmp($name, 'body') != 0) {
-			HTMLDiffer::diffDebug( "Starting $name node.\n" );
-			$this->endWord();
-
-			$newNode = new TagNode($this->currentParent, $name, $attributes);
-			$this->currentParent->children[] = $newNode;
-			$this->currentParent = $newNode;
-			$this->lastSibling = new DummyNode();
-			if ($this->whiteSpaceBeforeThis && !in_array(strtolower($this->currentParent->qName),TagNode::$blocks)) {
-				$this->currentParent->whiteBefore = true;
-			}
-			$this->whiteSpaceBeforeThis = false;
-			if(strcasecmp($name, 'pre') == 0) {
-				$this->notInPre = false;
-			}
-		}
-	}
-
-	public function endElement($parser, $name) {
-		if(strcasecmp($name, 'body') != 0) {
-			HTMLDiffer::diffDebug( "Ending $name node.\n");
-			if (0 == strcasecmp($name,'img')) {
-				// Insert a dummy leaf for the image
-				$img = new ImageNode($this->currentParent, $this->currentParent->attributes);
-				$this->currentParent->children[] = $img;
-				$img->whiteBefore = $this->whiteSpaceBeforeThis;
-				$this->lastSibling = $img;
-				$this->textNodes[] = $img;
-			}
-			$this->endWord();
-			if (!in_array(strtolower($this->currentParent->qName),TagNode::$blocks)) {
-				$this->lastSibling = $this->currentParent;
-			} else {
-				$this->lastSibling = new DummyNode();
-			}
-			$this->currentParent = $this->currentParent->parent;
-			$this->whiteSpaceBeforeThis = false;
-			if (!$this->notInPre && strcasecmp($name, 'pre') == 0) {
-				$this->notInPre = true;
-			}
-		} else {
-			$this->endDocument();
-		}
-	}
-
-	const regex = '/([\s\.\,\"\\\'\(\)\?\:\;\!\{\}\-\+\*\=\_\[\]\&\|\$]{1})/';
-	const whitespace = '/^[\s]{1}$/';
-	const delimiter = '/^[\s\.\,\"\\\'\(\)\?\:\;\!\{\}\-\+\*\=\_\[\]\&\|\$]{1}$/';
-
-	public function characters($parser, $data) {
-		$matches = preg_split(self::regex, $data, -1, PREG_SPLIT_DELIM_CAPTURE);
-
-		foreach($matches as &$word) {
-			if (preg_match(self::whitespace, $word) && $this->notInPre) {
-				$this->endWord();
-				$this->lastSibling->whiteAfter = true;
-				$this->whiteSpaceBeforeThis = true;
-			} else if (preg_match(self::delimiter, $word)) {
-				$this->endWord();
-				$textNode = new TextNode($this->currentParent, $word);
-				$this->currentParent->children[] = $textNode;
-				$textNode->whiteBefore = $this->whiteSpaceBeforeThis;
-				$this->whiteSpaceBeforeThis = false;
-				$this->lastSibling = $textNode;
-				$this->textNodes[] = $textNode;
-			} else {
-				$this->newWord .= $word;
-			}
-		}
-	}
-
-	private function endWord() {
-		if ($this->newWord !== '') {
-			$node = new TextNode($this->currentParent, $this->newWord);
-			$this->currentParent->children[] = $node;
-			$node->whiteBefore = $this->whiteSpaceBeforeThis;
-			$this->whiteSpaceBeforeThis = false;
-			$this->lastSibling = $node;
-			$this->textNodes[] = $node;
-			$this->newWord = "";
-		}
-	}
-
-	public function getDiffLines() {
-		return array_map(array('TextNode','toDiffLine'), $this->textNodes);
-	}
-}
-
-class TextNodeDiffer {
-
-	private $textNodes;
-	public $bodyNode;
-
-	private $oldTextNodes;
-	private $oldBodyNode;
-
-	private $newID = 0;
-
-	private $changedID = 0;
-
-	private $changedIDUsed = false;
-
-	// used to remove the whitespace between a red and green block
-	private $whiteAfterLastChangedPart = false;
-
-	private $deletedID = 0;
-
-	function __construct(DomTreeBuilder $tree, DomTreeBuilder $oldTree) {
-		$this->textNodes = $tree->textNodes;
-		$this->bodyNode = $tree->bodyNode;
-		$this->oldTextNodes = $oldTree->textNodes;
-		$this->oldBodyNode = $oldTree->bodyNode;
-	}
-
-	public function markAsNew($start, $end) {
-		if ($end <= $start) {
-			return;
-		}
-
-		if ($this->whiteAfterLastChangedPart) {
-			$this->textNodes[$start]->whiteBefore = false;
-		}
-
-		for ($i = $start; $i < $end; ++$i) {
-			$mod = new Modification(Modification::ADDED);
-			$mod->id = $this->newID;
-			$this->textNodes[$i]->modification = $mod;
-		}
-		if ($start < $end) {
-			$this->textNodes[$start]->modification->firstOfID = true;
-		}
-		++$this->newID;
-	}
-
-	public function handlePossibleChangedPart($leftstart, $leftend,	$rightstart, $rightend) {
-		$i = $rightstart;
-		$j = $leftstart;
-
-		if ($this->changedIDUsed) {
-			++$this->changedID;
-			$this->changedIDUsed = false;
-		}
-
-		$changes;
-		while ($i < $rightend) {
-			$acthis = new AncestorComparator($this->textNodes[$i]->getParentTree());
-			$acother = new AncestorComparator($this->oldTextNodes[$j]->getParentTree());
-			$result = $acthis->getResult($acother);
-			unset($acthis, $acother);
-
-			if ( $result ) {
-				$mod = new Modification(Modification::CHANGED);
-
-				if (!$this->changedIDUsed) {
-					$mod->firstOfID = true;
-				} else if (!is_null( $result ) && $result !== $this->changes) {
-					++$this->changedID;
-					$mod->firstOfID = true;
-				}
-
-				$mod->changes = $result;
-				$mod->id = $this->changedID;
-
-				$this->textNodes[$i]->modification = $mod;
-				$this->changes = $result;
-				$this->changedIDUsed = true;
-			} else if ($this->changedIDUsed) {
-				++$this->changedID;
-				$this->changedIDUsed = false;
-			}
-			++$i;
-			++$j;
-		}
-	}
-
-	public function markAsDeleted($start, $end, $before) {
-
-		if ($end <= $start) {
-			return;
-		}
-
-		if ($before > 0 && $this->textNodes[$before - 1]->whiteAfter) {
-			$this->whiteAfterLastChangedPart = true;
-		} else {
-			$this->whiteAfterLastChangedPart = false;
-		}
-
-		for ($i = $start; $i < $end; ++$i) {
-			$mod = new Modification(Modification::REMOVED);
-			$mod->id = $this->deletedID;
-
-			// oldTextNodes is used here because we're going to move its deleted
-			// elements to this tree!
-			$this->oldTextNodes[$i]->modification = $mod;
-		}
-		$this->oldTextNodes[$start]->modification->firstOfID = true;
-
-		$root = $this->oldTextNodes[$start]->getLastCommonParent($this->oldTextNodes[$end-1])->parent;
-
-		$junk1 = $junk2 = null;
-		$deletedNodes = $root->getMinimalDeletedSet($this->deletedID, $junk1, $junk2);
-
-		HTMLDiffer::diffDebug( "Minimal set of deleted nodes of size " . count($deletedNodes) . "\n" );
-
-		// Set prevLeaf to the leaf after which the old HTML needs to be
-		// inserted
-		if ($before > 0) {
-			$prevLeaf = $this->textNodes[$before - 1];
-		}
-		// Set nextLeaf to the leaf before which the old HTML needs to be
-		// inserted
-		if ($before < count($this->textNodes)) {
-			$nextLeaf = $this->textNodes[$before];
-		}
-
-		while (count($deletedNodes) > 0) {
-			if (isset($prevLeaf)) {
-				$prevResult = $prevLeaf->getLastCommonParent($deletedNodes[0]);
-			} else {
-				$prevResult = new LastCommonParentResult();
-				$prevResult->parent = $this->bodyNode;
-				$prevResult->indexInLastCommonParent = -1;
-			}
-			if (isset($nextleaf)) {
-				$nextResult = $nextLeaf->getLastCommonParent($deletedNodes[count($deletedNodes) - 1]);
-			} else {
-				$nextResult = new LastCommonParentResult();
-				$nextResult->parent = $this->bodyNode;
-				$nextResult->indexInLastCommonParent = $this->bodyNode->getNbChildren();
-			}
-
-			if ($prevResult->lastCommonParentDepth == $nextResult->lastCommonParentDepth) {
-				// We need some metric to choose which way to add-...
-				if ($deletedNodes[0]->parent === $deletedNodes[count($deletedNodes) - 1]->parent
-						&& $prevResult->parent === $nextResult->parent) {
-					// The difference is not in the parent
-					$prevResult->lastCommonParentDepth = $prevResult->lastCommonParentDepth + 1;
-				} else {
-					// The difference is in the parent, so compare them
-					// now THIS is tricky
-					$distancePrev = $deletedNodes[0]->parent->getMatchRatio($prevResult->parent);
-					$distanceNext = $deletedNodes[count($deletedNodes) - 1]->parent->getMatchRatio($nextResult->parent);
-
-					if ($distancePrev <= $distanceNext) {
-						$prevResult->lastCommonParentDepth = $prevResult->lastCommonParentDepth + 1;
-					} else {
-						$nextResult->lastCommonParentDepth = $nextResult->lastCommonParentDepth + 1;
-					}
-				}
-
-			}
-
-			if ($prevResult->lastCommonParentDepth > $nextResult->lastCommonParentDepth) {
-				// Inserting at the front
-				if ($prevResult->splittingNeeded) {
-					$prevLeaf->parent->splitUntil($prevResult->parent, $prevLeaf, true);
-				}
-				$prevLeaf = $deletedNodes[0]->copyTree();
-				unset($deletedNodes[0]);
-				$deletedNodes = array_values($deletedNodes);
-				$prevLeaf->setParent($prevResult->parent);
-				$prevResult->parent->addChildAbsolute($prevLeaf,$prevResult->indexInLastCommonParent + 1);
-			} else if ($prevResult->lastCommonParentDepth < $nextResult->lastCommonParentDepth) {
-				// Inserting at the back
-				if ($nextResult->splittingNeeded) {
-					$splitOccured = $nextLeaf->parent->splitUntil($nextResult->parent, $nextLeaf, false);
-					if ($splitOccured) {
-						// The place where to insert is shifted one place to the
-						// right
-						$nextResult->indexInLastCommonParent = $nextResult->indexInLastCommonParent + 1;
-					}
-				}
-				$nextLeaf = $deletedNodes[count(deletedNodes) - 1]->copyTree();
-				unset($deletedNodes[count(deletedNodes) - 1]);
-				$deletedNodes = array_values($deletedNodes);
-				$nextLeaf->setParent($nextResult->parent);
-				$nextResult->parent->addChildAbsolute($nextLeaf,$nextResult->indexInLastCommonParent);
-			}
-		}
-		++$this->deletedID;
-	}
-
-	public function expandWhiteSpace() {
-		$this->bodyNode->expandWhiteSpace();
-	}
-
-	public function lengthNew(){
-		return count($this->textNodes);
-	}
-
-	public function lengthOld(){
-		return count($this->oldTextNodes);
-	}
-}
-
-class HTMLDiffer {
-
-	private $output;
-	private static $debug = '';
-
-	function __construct($output) {
-		$this->output = $output;
-	}
-
-	function htmlDiff($from, $to) {
-		wfProfileIn( __METHOD__ );
-		// Create an XML parser
-		$xml_parser = xml_parser_create('');
-
-		$domfrom = new DomTreeBuilder();
-
-		// Set the functions to handle opening and closing tags
-		xml_set_element_handler($xml_parser, array($domfrom, "startElement"), array($domfrom, "endElement"));
-
-		// Set the function to handle blocks of character data
-		xml_set_character_data_handler($xml_parser, array($domfrom, "characters"));
-
-		HTMLDiffer::diffDebug( "Parsing " . strlen($from) . " characters worth of HTML\n" );
-		if (!xml_parse($xml_parser, ''.Sanitizer::hackDocType().'', false)
-					|| !xml_parse($xml_parser, $from, false)
-					|| !xml_parse($xml_parser, '', true)){
-			$error = xml_error_string(xml_get_error_code($xml_parser));
-			$line = xml_get_current_line_number($xml_parser);
-			HTMLDiffer::diffDebug( "XML error: $error at line $line\n" );
-		}
-		xml_parser_free($xml_parser);
-		unset($from);
-
-		$xml_parser = xml_parser_create('');
-
-		$domto = new DomTreeBuilder();
-
-		// Set the functions to handle opening and closing tags
-		xml_set_element_handler($xml_parser, array($domto, "startElement"), array($domto, "endElement"));
-
-		// Set the function to handle blocks of character data
-		xml_set_character_data_handler($xml_parser, array($domto, "characters"));
-
-		HTMLDiffer::diffDebug( "Parsing " . strlen($to) . " characters worth of HTML\n" );
-		if (!xml_parse($xml_parser, ''.Sanitizer::hackDocType().'', false)
-		|| !xml_parse($xml_parser, $to, false)
-		|| !xml_parse($xml_parser, '', true)){
-			$error = xml_error_string(xml_get_error_code($xml_parser));
-			$line = xml_get_current_line_number($xml_parser);
-			HTMLDiffer::diffDebug( "XML error: $error at line $line\n" );
-		}
-		xml_parser_free($xml_parser);
-		unset($to);
-
-		$diffengine = new WikiDiff3();
-		$differences = $this->preProcess($diffengine->diff_range($domfrom->getDiffLines(), $domto->getDiffLines()));
-		unset($xml_parser, $diffengine);
-
-		$domdiffer = new TextNodeDiffer($domto, $domfrom);
-
-		$currentIndexLeft = 0;
-		$currentIndexRight = 0;
-		foreach ($differences as &$d) {
-			if ($d->leftstart > $currentIndexLeft) {
-				$domdiffer->handlePossibleChangedPart($currentIndexLeft, $d->leftstart,
-					$currentIndexRight, $d->rightstart);
-			}
-			if ($d->leftlength > 0) {
-				$domdiffer->markAsDeleted($d->leftstart, $d->leftend, $d->rightstart);
-			}
-			$domdiffer->markAsNew($d->rightstart, $d->rightend);
-
-			$currentIndexLeft = $d->leftend;
-			$currentIndexRight = $d->rightend;
-		}
-		$oldLength = $domdiffer->lengthOld();
-		if ($currentIndexLeft < $oldLength) {
-			$domdiffer->handlePossibleChangedPart($currentIndexLeft, $oldLength, $currentIndexRight, $domdiffer->lengthNew());
-		}
-		$domdiffer->expandWhiteSpace();
-		$output = new HTMLOutput('htmldiff', $this->output);
-		$output->parse($domdiffer->bodyNode);
-		wfProfileOut( __METHOD__ );
-	}
-
-	private function preProcess(/*array*/ $differences) {
-		$newRanges = array();
-
-		$nbDifferences = count($differences);
-		for ($i = 0; $i < $nbDifferences; ++$i) {
-			$leftStart = $differences[$i]->leftstart;
-			$leftEnd = $differences[$i]->leftend;
-			$rightStart = $differences[$i]->rightstart;
-			$rightEnd = $differences[$i]->rightend;
-
-			$leftLength = $leftEnd - $leftStart;
-			$rightLength = $rightEnd - $rightStart;
-
-			while ($i + 1 < $nbDifferences && self::score($leftLength,
-						$differences[$i + 1]->leftlength,
-						$rightLength,
-						$differences[$i + 1]->rightlength)
-					> ($differences[$i + 1]->leftstart - $leftEnd)) {
-				$leftEnd = $differences[$i + 1]->leftend;
-				$rightEnd = $differences[$i + 1]->rightend;
-				$leftLength = $leftEnd - $leftStart;
-				$rightLength = $rightEnd - $rightStart;
-				++$i;
-			}
-			$newRanges[] = new RangeDifference($leftStart, $leftEnd, $rightStart, $rightEnd);
-		}
-		return $newRanges;
-	}
-
-	/**
-	 * Heuristic to merge differences for readability.
-	 */
-	public static function score($ll, $nll, $rl, $nrl) {
-		if (($ll == 0 && $nll == 0)
-				|| ($rl == 0 && $nrl == 0)) {
-			return 0;
-		}
-		$numbers = array($ll, $nll, $rl, $nrl);
-		$d = 0;
-		foreach ($numbers as &$number) {
-			while ($number > 3) {
-				$d += 3;
-				$number -= 3;
-				$number *= 0.5;
-			}
-			$d += $number;
-
-		}
-		return $d / (1.5 * count($numbers));
-	}
-
-	/**
-	 * Add to debug output
-	 * @param string $str Debug output
-	 */
-	public static function diffDebug( $str ) {
-		self :: $debug .= $str;
-	}
-	
-	/**
-	 * Get debug output
-	 * @return string
-	 */
-	public static function getDebugOutput() {
-		return self :: $debug;
-	}
-
-}
-
-class TextOnlyComparator {
-
-	public $leafs = array();
-
-	function _construct(TagNode $tree) {
-		$this->addRecursive($tree);
-		$this->leafs = array_map(array('TextNode','toDiffLine'), $this->leafs);
-	}
-
-	private function addRecursive(TagNode $tree) {
-		foreach ($tree->children as &$child) {
-			if ($child instanceof TagNode) {
-				$this->addRecursive($child);
-			} else if ($child instanceof TextNode) {
-				$this->leafs[] = $node;
-			}
-		}
-	}
-
-	public function getMatchRatio(TextOnlyComparator $other) {
-		$nbOthers = count($other->leafs);
-		$nbThis = count($this->leafs);
-		if($nbOthers == 0 || $nbThis == 0){
-			return -log(0);
-		}
-
-		$diffengine = new WikiDiff3(25000, 1.35);
-		$diffengine->diff($this->leafs, $other->leafs);
-
-		$lcsLength = $diffengine->getLcsLength();
-
-		$distanceThis = $nbThis-$lcsLength;
-
-		return (2.0 - $lcsLength/$nbOthers - $lcsLength/$nbThis) / 2.0;
-	}
-}
-
-/**
- * A comparator used when calculating the difference in ancestry of two Nodes.
- */
-class AncestorComparator {
-
-	public $ancestors;
-	public $ancestorsText;
-
-	function __construct(/*array*/ $ancestors) {
-		$this->ancestors = $ancestors;
-		$this->ancestorsText = array_map(array('TagNode','toDiffLine'), $ancestors);
-	}
-
-	public $compareTxt = "";
-
-	public function getResult(AncestorComparator $other) {
-
-		$diffengine = new WikiDiff3(10000, 1.35);
-		$differences = $diffengine->diff_range($other->ancestorsText,$this->ancestorsText);
-
-		if (count($differences) == 0){
-			return null;
-		}
-		$changeTxt = new ChangeTextGenerator($this, $other);
-
-		return $changeTxt->getChanged($differences)->toString();;
-	}
-}
-
-class ChangeTextGenerator {
-
-	private $ancestorComparator;
-	private $other;
-
-	private $factory;
-
-	function __construct(AncestorComparator $ancestorComparator, AncestorComparator $other) {
-		$this->ancestorComparator = $ancestorComparator;
-		$this->other = $other;
-		$this->factory = new TagToStringFactory();
-	}
-
-	public function getChanged(/*array*/ $differences) {
-		$txt = new ChangeText;
-		$rootlistopened = false;
-		if (count($differences) > 1) {
-			$txt->addHtml('
    ');
-			$rootlistopened = true;
-		}
-		$nbDifferences = count($differences);
-		for ($j = 0; $j < $nbDifferences; ++$j) {
-			$d = $differences[$j];
-			$lvl1listopened = false;
-			if ($rootlistopened) {
-				$txt->addHtml('
  • ');
-			}
-			if ($d->leftlength + $d->rightlength > 1) {
-				$txt->addHtml('
      ');
-				$lvl1listopened = true;
-			}
-			// left are the old ones
-			for ($i = $d->leftstart; $i < $d->leftend; ++$i) {
-				if ($lvl1listopened){
-					$txt->addHtml('
    • ');
-				}
-				// add a bullet for a old tag
-				$this->addTagOld($txt, $this->other->ancestors[$i]);
-				if ($lvl1listopened){
-					$txt->addHtml('
      • ');
-				}
-			}
-			// right are the new ones
-			for ($i = $d->rightstart; $i < $d->rightend; ++$i) {
-				if ($lvl1listopened){
-					$txt->addHtml('
    • ');
-				}
-				// add a bullet for a new tag
-				$this->addTagNew($txt, $this->ancestorComparator->ancestors[$i]);
-
-				if ($lvl1listopened){
-					$txt->addHtml('
      • ');
-				}
-			}
-			if ($lvl1listopened) {
-				$txt->addHtml('
    ');
-			}
-			if ($rootlistopened) {
-				$txt->addHtml('
    • ');
-			}
-		}
-		if ($rootlistopened) {
-			$txt->addHtml('
');
-		}
-		return $txt;
-	}
-
-	private function addTagOld(ChangeText $txt, TagNode $ancestor) {
-		$this->factory->create($ancestor)->getRemovedDescription($txt);
-	}
-
-	private function addTagNew(ChangeText $txt, TagNode $ancestor) {
-		$this->factory->create($ancestor)->getAddedDescription($txt);
-	}
-}
-
-class ChangeText {
-
-	private $txt = "";
-
-	public function addHtml($s) {
-		$this->txt .= $s;
-	}
-
-	public function toString() {
-		return $this->txt;
-	}
-}
-
-class TagToStringFactory {
-
-	private static $containerTags = array('html', 'body', 'p', 'blockquote',
-		'h1', 'h2', 'h3', 'h4', 'h5', 'pre', 'div', 'ul', 'ol', 'li',
-		'table', 'tbody', 'tr', 'td', 'th', 'br', 'hr', 'code', 'dl',
-		'dt', 'dd', 'input', 'form', 'img', 'span', 'a');
-
-	private static $styleTags = array('i', 'b', 'strong', 'em', 'font',
-		'big', 'del', 'tt', 'sub', 'sup', 'strike');
-
-	const MOVED = 1;
-	const STYLE = 2;
-	const UNKNOWN = 4;
-
-	public function create(TagNode $node) {
-		$sem = $this->getChangeSemantic($node->qName);
-		if (strcasecmp($node->qName,'a') == 0) {
-			return new AnchorToString($node, $sem);
-		}
-		if (strcasecmp($node->qName,'img') == 0) {
-			return new NoContentTagToString($node, $sem);
-		}
-		return new TagToString($node, $sem);
-	}
-
-	protected function getChangeSemantic($qname) {
-		if (in_array(strtolower($qname),self::$containerTags)) {
-			return self::MOVED;
-		}
-		if (in_array(strtolower($qname),self::$styleTags)) {
-			return self::STYLE;
-		}
-		return self::UNKNOWN;
-	}
-}
-
-class TagToString {
-
-	protected $node;
-
-	protected $sem;
-
-	function __construct(TagNode $node, $sem) {
-		$this->node = $node;
-		$this->sem = $sem;
-	}
-
-	public function getRemovedDescription(ChangeText $txt) {
-		$tagDescription = wfMsgExt('diff-' . $this->node->qName, 'parseinline' );
-		if( wfEmptyMsg( 'diff-' . $this->node->qName, $tagDescription ) ){
-			$tagDescription = "<" . $this->node->qName . ">";
-		}
-		if ($this->sem == TagToStringFactory::MOVED) {
-			$txt->addHtml( wfMsgExt( 'diff-movedoutof', 'parseinline', $tagDescription ) );
-		} else if ($this->sem == TagToStringFactory::STYLE) {
-			$txt->addHtml( wfMsgExt( 'diff-styleremoved' , 'parseinline', $tagDescription ) );
-		} else {
-			$txt->addHtml( wfMsgExt( 'diff-removed' , 'parseinline', $tagDescription ) );
-		}
-		$this->addAttributes($txt, $this->node->attributes);
-		$txt->addHtml('.');
-	}
-
-	public function getAddedDescription(ChangeText $txt) {
-		$tagDescription = wfMsgExt('diff-' . $this->node->qName, 'parseinline' );
-		if( wfEmptyMsg( 'diff-' . $this->node->qName, $tagDescription ) ){
-			$tagDescription = "<" . $this->node->qName . ">";
-		}
-		if ($this->sem == TagToStringFactory::MOVED) {
-			$txt->addHtml( wfMsgExt( 'diff-movedto' , 'parseinline', $tagDescription) );
-		} else if ($this->sem == TagToStringFactory::STYLE) {
-			$txt->addHtml( wfMsgExt( 'diff-styleadded', 'parseinline', $tagDescription ) );
-		} else {
-			$txt->addHtml( wfMsgExt( 'diff-added', 'parseinline', $tagDescription ) );
-		}
-		$this->addAttributes($txt, $this->node->attributes);
-		$txt->addHtml('.');
-	}
-
-	protected function addAttributes(ChangeText $txt, array $attributes) {
-		if (count($attributes) < 1) {
-			return;
-		}
-		$firstOne = true;
-		$nbAttributes_min_1 = count($attributes)-1;
-		$keys = array_keys($attributes);
-		for ($i=0;$i<$nbAttributes_min_1;$i++) {
-			$key = $keys[$i];
-			$attr = $attributes[$key];
-			if($firstOne) {
-				$firstOne = false;
-				$txt->addHtml( wfMsgExt('diff-with', 'escapenoentities', $this->translateArgument($key), htmlspecialchars($attr) ) );
-				continue;
-			}
-			$txt->addHtml( wfMsgExt( 'comma-separator', 'escapenoentities' ) .
-				wfMsgExt( 'diff-with-additional', 'escapenoentities',
-				$this->translateArgument( $key ), htmlspecialchars( $attr ) )
-			);
-		}
-
-		if ($nbAttributes_min_1 > 0) {
-			$txt->addHtml( wfMsgExt( 'diff-with-final', 'escapenoentities',
-			$this->translateArgument($keys[$nbAttributes_min_1]),
-			htmlspecialchars($attributes[$keys[$nbAttributes_min_1]]) ) );
-		}
-	}
-
-	protected function translateArgument($name) {
-		$translation = wfMsgExt('diff-' . $name, 'parseinline' );
-		if ( wfEmptyMsg( 'diff-' . $name, $translation ) ) {
-			$translation = "<" . $name . ">";;
-		}
-		return htmlspecialchars( $translation );
-	}
-}
-
-class NoContentTagToString extends TagToString {
-
-	function __construct(TagNode $node, $sem) {
-		parent::__construct($node, $sem);
-	}
-
-	public function getAddedDescription(ChangeText $txt) {
-		$tagDescription = wfMsgExt('diff-' . $this->node->qName, 'parseinline' );
-		if( wfEmptyMsg( 'diff-' . $this->node->qName, $tagDescription ) ){
-			$tagDescription = "<" . $this->node->qName . ">";
-		}
-		$txt->addHtml( wfMsgExt('diff-changedto', 'parseinline', $tagDescription ) );
-		$this->addAttributes($txt, $this->node->attributes);
-		$txt->addHtml('.');
-	}
-
-	public function getRemovedDescription(ChangeText $txt) {
-		$tagDescription = wfMsgExt('diff-' . $this->node->qName, 'parseinline' );
-		if( wfEmptyMsg( 'diff-' . $this->node->qName, $tagDescription ) ){
-			$tagDescription = "<" . $this->node->qName . ">";
-		}
-		$txt->addHtml( wfMsgExt('diff-changedfrom', 'parseinline', $tagDescription ) );
-		$this->addAttributes($txt, $this->node->attributes);
-		$txt->addHtml('.');
-	}
-}
-
-class AnchorToString extends TagToString {
-
-	function __construct(TagNode $node, $sem) {
-		parent::__construct($node, $sem);
-	}
-
-	protected function addAttributes(ChangeText $txt, array $attributes) {
-		if (array_key_exists('href', $attributes)) {
-			$txt->addHtml(' ' . wfMsgExt( 'diff-withdestination', 'parseinline', htmlspecialchars($attributes['href']) ) );
-			unset($attributes['href']);
-		}
-		parent::addAttributes($txt, $attributes);
-	}
-}
-
-/**
- * Takes a branch root and creates an HTML file for it.
- */
-class HTMLOutput{
-
-	private $prefix;
-	private $handler;
-
-	function __construct($prefix, $handler) {
-		$this->prefix = $prefix;
-		$this->handler = $handler;
-	}
-
-	public function parse(TagNode $node) {
-		$handler = &$this->handler;
-
-		if (strcasecmp($node->qName, 'img') != 0 && strcasecmp($node->qName, 'body') != 0) {
-			$handler->startElement($node->qName, $node->attributes);
-		}
-
-		$newStarted = false;
-		$remStarted = false;
-		$changeStarted = false;
-		$changeTXT = '';
-
-		foreach ($node->children as &$child) {
-			if ($child instanceof TagNode) {
-				if ($newStarted) {
-					$handler->endElement('span');
-					$newStarted = false;
-				} else if ($changeStarted) {
-					$handler->endElement('span');
-					$changeStarted = false;
-				} else if ($remStarted) {
-					$handler->endElement('span');
-					$remStarted = false;
-				}
-				$this->parse($child);
-			} else if ($child instanceof TextNode) {
-				$mod = $child->modification;
-
-				if ($newStarted && ($mod->type != Modification::ADDED || $mod->firstOfID)) {
-					$handler->endElement('span');
-					$newStarted = false;
-				} else if ($changeStarted && ($mod->type != Modification::CHANGED
-						|| $mod->changes != $changeTXT || $mod->firstOfID)) {
-					$handler->endElement('span');
-					$changeStarted = false;
-				} else if ($remStarted && ($mod->type != Modification::REMOVED || $mod ->firstOfID)) {
-					$handler->endElement('span');
-					$remStarted = false;
-				}
-
-				// no else because a removed part can just be closed and a new
-				// part can start
-				if (!$newStarted && $mod->type == Modification::ADDED) {
-					$attrs = array('class' => 'diff-html-added');
-					if ($mod->firstOfID) {
-						$attrs['id'] = "added-{$this->prefix}-{$mod->id}";
-					}
-					$handler->startElement('span', $attrs);
-					$newStarted = true;
-				} else if (!$changeStarted && $mod->type == Modification::CHANGED) {
-					$attrs = array('class' => 'diff-html-changed');
-					if ($mod->firstOfID) {
-						$attrs['id'] = "changed-{$this->prefix}-{$mod->id}";
-					}
-					$handler->startElement('span', $attrs);
-
-					//tooltip
-					$handler->startElement('span', array('class' => 'tip'));
-					$handler->html($mod->changes);
-					$handler->endElement('span');
-
-					$changeStarted = true;
-					$changeTXT = $mod->changes;
-				} else if (!$remStarted && $mod->type == Modification::REMOVED) {
-					$attrs = array('class'=>'diff-html-removed');
-					if ($mod->firstOfID) {
-						$attrs['id'] = "removed-{$this->prefix}-{$mod->id}";
-					}
-					$handler->startElement('span', $attrs);
-					$remStarted = true;
-				}
-
-				$chars = $child->text;
-
-				if ($child instanceof ImageNode) {
-					$this->writeImage($child);
-				} else {
-					$handler->characters($chars);
-				}
-			}
-		}
-
-		if ($newStarted) {
-			$handler->endElement('span');
-			$newStarted = false;
-		} else if ($changeStarted) {
-			$handler->endElement('span');
-			$changeStarted = false;
-		} else if ($remStarted) {
-			$handler->endElement('span');
-			$remStarted = false;
-		}
-
-		if (strcasecmp($node->qName, 'img') != 0
-				&& strcasecmp($node->qName, 'body') != 0) {
-			$handler->endElement($node->qName);
-		}
-	}
-
-	private function writeImage(ImageNode  $imgNode) {
-		$attrs = $imgNode->attributes;
-		$this->handler->startElement('img', $attrs);
-		$this->handler->endElement('img');
-	}
-}
-
-class DelegatingContentHandler {
-
-	private $delegate;
-
-	function __construct($delegate) {
-		$this->delegate = $delegate;
-	}
-
-	function startElement($qname, /*array*/ $arguments) {
-		$this->delegate->addHtml(Xml::openElement($qname, $arguments));
-	}
-
-	function endElement($qname){
-		$this->delegate->addHtml(Xml::closeElement($qname));
-	}
-
-	function characters($chars){
-		$this->delegate->addHtml(htmlspecialchars($chars));
-	}
-
-	function html($html){
-		$this->delegate->addHtml($html);
-	}
-}
diff --git a/includes/diff/Nodes.php b/includes/diff/Nodes.php
deleted file mode 100644
index 1b1363d4..00000000
--- a/includes/diff/Nodes.php
+++ /dev/null
@@ -1,439 +0,0 @@
-
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- * or see http://www.gnu.org/
- * 
- */
- 
-/**
- * Any element in the DOM tree of an HTML document.
- * @ingroup DifferenceEngine
- */
-class Node {
-
-	public $parent;
-
-	protected $parentTree;
-
-	public $whiteBefore = false;
-
-	public $whiteAfter = false;
-
-	function __construct($parent) {
-		$this->parent = $parent;
-	}
-
-	public function getParentTree() {
-		if (!isset($this->parentTree)) {
-			if (!is_null($this->parent)) {
-				$this->parentTree = $this->parent->getParentTree();
-				$this->parentTree[] = $this->parent;
-			} else {
-				$this->parentTree = array();
-			}
-		}
-		return $this->parentTree;
-	}
-
-	public function getLastCommonParent(Node $other) {
-		$result = new LastCommonParentResult();
-
-		$myParents = $this->getParentTree();
-		$otherParents = $other->getParentTree();
-
-		$i = 1;
-		$isSame = true;
-		$nbMyParents = count($myParents);
-		$nbOtherParents = count($otherParents);
-		while ($isSame && $i < $nbMyParents && $i < $nbOtherParents) {
-			if (!$myParents[$i]->openingTag === $otherParents[$i]->openingTag) {
-				$isSame = false;
-			} else {
-				// After a while, the index i-1 must be the last common parent
-				$i++;
-			}
-		}
-
-		$result->lastCommonParentDepth = $i - 1;
-		$result->parent = $myParents[$i - 1];
-
-		if (!$isSame || $nbMyParents > $nbOtherParents) {
-			// Not all tags matched, or all tags matched but
-			// there are tags left in this tree
-			$result->indexInLastCommonParent = $myParents[$i - 1]->getIndexOf($myParents[$i]);
-			$result->splittingNeeded = true;
-		} else if ($nbMyParents <= $nbOtherParents) {
-			$result->indexInLastCommonParent = $myParents[$i - 1]->getIndexOf($this);
-		}
-		return $result;
-	}
-
-	public function setParent($parent) {
-		$this->parent = $parent;
-		unset($this->parentTree);
-	}
-
-	public function inPre() {
-		$tree = $this->getParentTree();
-		foreach ($tree as &$ancestor) {
-			if ($ancestor->isPre()) {
-				return true;
-			}
-		}
-		return false;
-	}
-}
-
-/**
- * Node that can contain other nodes. Represents an HTML tag.
- * @ingroup DifferenceEngine
- */
-class TagNode extends Node {
-
-	public $children = array();
-
-	public $qName;
-
-	public $attributes = array();
-
-	public $openingTag;
-
-	function __construct($parent, $qName, /*array*/ $attributes) {
-		parent::__construct($parent);
-		$this->qName = strtolower($qName);
-		foreach($attributes as $key => &$value){
-			$this->attributes[strtolower($key)] = $value;
-		}
-		return $this->openingTag = Xml::openElement($this->qName, $this->attributes);
-	}
-
-	public function addChildAbsolute(Node $node, $index) {
-		array_splice($this->children, $index, 0, array($node));
-	}
-
-	public function getIndexOf(Node $child) {
-		// don't trust array_search with objects
-		foreach ($this->children as $key => &$value){
-			if ($value === $child) {
-				return $key;
-			}
-		}
-		return null;
-	}
-
-	public function getNbChildren() {
-		return count($this->children);
-	}
-
-	public function getMinimalDeletedSet($id, &$allDeleted, &$somethingDeleted) {
-		$nodes = array();
-
-		$allDeleted = false;
-		$somethingDeleted = false;
-		$hasNonDeletedDescendant = false;
-
-		if (empty($this->children)) {
-			return $nodes;
-		}
-
-		foreach ($this->children as &$child) {
-			$allDeleted_local = false;
-			$somethingDeleted_local = false;
-			$childrenChildren = $child->getMinimalDeletedSet($id, $allDeleted_local, $somethingDeleted_local);
-			if ($somethingDeleted_local) {
-				$nodes = array_merge($nodes, $childrenChildren);
-				$somethingDeleted = true;
-			}
-			if (!$allDeleted_local) {
-				$hasNonDeletedDescendant = true;
-			}
-		}
-		if (!$hasNonDeletedDescendant) {
-			$nodes = array($this);
-			$allDeleted = true;
-		}
-		return $nodes;
-	}
-
-	public function splitUntil(TagNode $parent, Node $split, $includeLeft) {
-		$splitOccured = false;
-		if ($parent !== $this) {
-			$part1 = new TagNode(null, $this->qName, $this->attributes);
-			$part2 = new TagNode(null, $this->qName, $this->attributes);
-			$part1->setParent($this->parent);
-			$part2->setParent($this->parent);
-
-			$onSplit = false;
-			$pastSplit = false;
-			foreach ($this->children as &$child)
-			{
-				if ($child === $split) {
-					$onSplit = true;
-				}
-				if(!$pastSplit || ($onSplit && $includeLeft)) {
-					$child->setParent($part1);
-					$part1->children[] = $child;
-				} else {
-					$child->setParent($part2);
-					$part2->children[] = $child;
-				}
-				if ($onSplit) {
-					$onSplit = false;
-					$pastSplit = true;
-				}
-			}
-			$myindexinparent = $this->parent->getIndexOf($this);
-			if (!empty($part1->children)) {
-				$this->parent->addChildAbsolute($part1, $myindexinparent);
-			}
-			if (!empty($part2->children)) {
-				$this->parent->addChildAbsolute($part2, $myindexinparent);
-			}
-			if (!empty($part1->children) && !empty($part2->children)) {
-				$splitOccured = true;
-			}
-
-			$this->parent->removeChild($myindexinparent);
-
-			if ($includeLeft) {
-				$this->parent->splitUntil($parent, $part1, $includeLeft);
-			} else {
-				$this->parent->splitUntil($parent, $part2, $includeLeft);
-			}
-		}
-		return $splitOccured;
-
-	}
-
-	private function removeChild($index) {
-		unset($this->children[$index]);
-		$this->children = array_values($this->children);
-	}
-
-	public static $blocks = array('html', 'body','p','blockquote', 'h1',
-		'h2', 'h3', 'h4', 'h5', 'pre', 'div', 'ul', 'ol', 'li', 'table',
-		'tbody', 'tr', 'td', 'th', 'br');
-
-	public function copyTree() {
-		$newThis = new TagNode(null, $this->qName, $this->attributes);
-		$newThis->whiteBefore = $this->whiteBefore;
-		$newThis->whiteAfter = $this->whiteAfter;
-		foreach ($this->children as &$child) {
-			$newChild = $child->copyTree();
-			$newChild->setParent($newThis);
-			$newThis->children[] = $newChild;
-		}
-		return $newThis;
-	}
-
-	public function getMatchRatio(TagNode $other) {
-		$txtComp = new TextOnlyComparator($other);
-		return $txtComp->getMatchRatio(new TextOnlyComparator($this));
-	}
-
-	public function expandWhiteSpace() {
-		$shift = 0;
-		$spaceAdded = false;
-
-		$nbOriginalChildren = $this->getNbChildren();
-		for ($i = 0; $i < $nbOriginalChildren; ++$i) {
-			$child = $this->children[$i + $shift];
-
-			if ($child instanceof TagNode) {
-				if (!$child->isPre()) {
-					$child->expandWhiteSpace();
-				}
-			}
-			if (!$spaceAdded && $child->whiteBefore) {
-				$ws = new WhiteSpaceNode(null, ' ', $child->getLeftMostChild());
-				$ws->setParent($this);
-				$this->addChildAbsolute($ws,$i + ($shift++));
-			}
-			if ($child->whiteAfter) {
-				$ws = new WhiteSpaceNode(null, ' ', $child->getRightMostChild());
-				$ws->setParent($this);
-				$this->addChildAbsolute($ws,$i + 1 + ($shift++));
-				$spaceAdded = true;
-			} else {
-				$spaceAdded = false;
-			}
-
-		}
-	}
-
-	public function getLeftMostChild() {
-		if (empty($this->children)) {
-			return $this;
-		}
-		return $this->children[0]->getLeftMostChild();
-	}
-
-	public function getRightMostChild() {
-		if (empty($this->children)) {
-			return $this;
-		}
-		return $this->children[$this->getNbChildren() - 1]->getRightMostChild();
-	}
-
-	public function isPre() {
-		return 0 == strcasecmp($this->qName,'pre');
-	}
-
-	public static function toDiffLine(TagNode $node) {
-		return $node->openingTag;
-	}
-}
-
-/**
- * Represents a piece of text in the HTML file.
- * @ingroup DifferenceEngine
- */
-class TextNode extends Node {
-
-	public $text;
-
-	public $modification;
-
-	function __construct($parent, $text) {
-		parent::__construct($parent);
-		$this->modification = new Modification(Modification::NONE);
-		$this->text = $text;
-	}
-
-	public function copyTree() {
-		$clone = clone $this;
-		$clone->setParent(null);
-		return $clone;
-	}
-
-	public function getLeftMostChild() {
-		return $this;
-	}
-
-	public function getRightMostChild() {
-		return $this;
-	}
-
-	public function getMinimalDeletedSet($id, &$allDeleted, &$somethingDeleted) {
-		if ($this->modification->type == Modification::REMOVED
-					&& $this->modification->id == $id){
-			$somethingDeleted = true;
-			$allDeleted = true;
-			return array($this);
-		}
-		return array();
-	}
-
-	public function isSameText($other) {
-		if (is_null($other) || ! $other instanceof TextNode) {
-			return false;
-		}
-		return str_replace('\n', ' ',$this->text) === str_replace('\n', ' ',$other->text);
-	}
-
-	public static function toDiffLine(TextNode $node) {
-		return str_replace('\n', ' ',$node->text);
-	}
-}
-
-/**
- * @todo Document
- * @ingroup DifferenceEngine
- */
-class WhiteSpaceNode extends TextNode {
-
-	function __construct($parent, $s, Node $like = null) {
-		parent::__construct($parent, $s);
-		if(!is_null($like) && $like instanceof TextNode) {
-			$newModification = clone $like->modification;
-			$newModification->firstOfID = false;
-			$this->modification = $newModification;
-		}
-	}
-}
-
-/**
- * Represents the root of a HTML document.
- * @ingroup DifferenceEngine
- */
-class BodyNode extends TagNode {
-
-	function __construct() {
-		parent::__construct(null, 'body', array());
-	}
-
-	public function copyTree() {
-		$newThis = new BodyNode();
-		foreach ($this->children as &$child) {
-			$newChild = $child->copyTree();
-			$newChild->setParent($newThis);
-			$newThis->children[] = $newChild;
-		}
-		return $newThis;
-	}
-
-	public function getMinimalDeletedSet($id, &$allDeleted, &$somethingDeleted) {
-		$nodes = array();
-		foreach ($this->children as &$child) {
-			$childrenChildren = $child->getMinimalDeletedSet($id,
-						$allDeleted, $somethingDeleted);
-			$nodes = array_merge($nodes, $childrenChildren);
-		}
-		return $nodes;
-	}
-
-}
-
-/**
- * Represents an image in HTML. Even though images do not contain any text they
- * are independent visible objects on the page. They are logically a TextNode.
- * @ingroup DifferenceEngine
- */
-class ImageNode extends TextNode {
-
-	public $attributes;
-
-	function __construct(TagNode $parent, /*array*/ $attrs) {
-		if(!array_key_exists('src', $attrs)) {
-			HTMLDiffer::diffDebug( "Image without a source\n" );
-			parent::__construct($parent, '');
-		}else{
-			parent::__construct($parent, '' . strtolower($attrs['src']) . '');
-		}
-		$this->attributes = $attrs;
-	}
-
-	public function isSameText($other) {
-		if (is_null($other) || ! $other instanceof ImageNode) {
-			return false;
-		}
-		return $this->text === $other->text;
-	}
-
-}
-
-/**
- * No-op node
- * @ingroup DifferenceEngine
- */
-class DummyNode extends Node {
-
-	function __construct() {
-		// no op
-	}
-
-}
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