$wgStyleVersion!
[lhc/web/wiklou.git] / includes / SpecialUndelete.php
index a156b97..c08a777 100644 (file)
@@ -4,52 +4,93 @@
  * Special page allowing users with the appropriate permissions to view
  * and restore deleted content
  *
- * @package MediaWiki
- * @subpackage Special pages
+ * @addtogroup SpecialPage
  */
 
 /**
- *
+ * Constructor
  */
 function wfSpecialUndelete( $par ) {
-    global $wgRequest;
+       global $wgRequest;
 
        $form = new UndeleteForm( $wgRequest, $par );
        $form->execute();
 }
 
 /**
- *
- * @package MediaWiki
- * @subpackage SpecialPage
+ * Used to show archived pages and eventually restore them.
+ * @addtogroup SpecialPage
  */
 class PageArchive {
-       var $title;
+       protected $title;
+       var $fileStatus;
 
-       function PageArchive( &$title ) {
+       function __construct( $title ) {
                if( is_null( $title ) ) {
                        throw new MWException( 'Archiver() given a null title.');
                }
-               $this->title =& $title;
+               $this->title = $title;
        }
 
        /**
         * List all deleted pages recorded in the archive table. Returns result
         * wrapper with (ar_namespace, ar_title, count) fields, ordered by page
-        * namespace/title. Can be called staticaly.
+        * namespace/title.
         *
         * @return ResultWrapper
         */
-       /* static */ function listAllPages() {
-               $dbr =& wfGetDB( DB_SLAVE );
-               $archive = $dbr->tableName( 'archive' );
-
-               $sql = "SELECT ar_namespace,ar_title, COUNT(*) AS count FROM $archive " .
-                 "GROUP BY ar_namespace,ar_title ORDER BY ar_namespace,ar_title";
-
-               return $dbr->resultObject( $dbr->query( $sql, 'PageArchive::listAllPages' ) );
+       public static function listAllPages() {
+               $dbr = wfGetDB( DB_SLAVE );
+               return self::listPages( $dbr, '' );
+       }
+       
+       /**
+        * List deleted pages recorded in the archive table matching the
+        * given title prefix.
+        * Returns result wrapper with (ar_namespace, ar_title, count) fields.
+        *
+        * @return ResultWrapper
+        */
+       public static function listPagesByPrefix( $prefix ) {
+               $dbr = wfGetDB( DB_SLAVE );
+               
+               $title = Title::newFromText( $prefix );
+               if( $title ) {
+                       $ns = $title->getNamespace();
+                       $encPrefix = $dbr->escapeLike( $title->getDBkey() );
+               } else {
+                       // Prolly won't work too good
+                       // @todo handle bare namespace names cleanly?
+                       $ns = 0;
+                       $encPrefix = $dbr->escapeLike( $prefix );
+               }
+               $conds = array(
+                       'ar_namespace' => $ns,
+                       "ar_title LIKE '$encPrefix%'",
+               );
+               return self::listPages( $dbr, $conds );
        }
 
+       protected static function listPages( $dbr, $condition ) {
+               return $dbr->resultObject(
+                       $dbr->select(
+                               array( 'archive' ),
+                               array(
+                                       'ar_namespace',
+                                       'ar_title',
+                                       'COUNT(*) AS count',
+                               ),
+                               $condition,
+                               __METHOD__,
+                               array(
+                                       'GROUP BY' => 'ar_namespace,ar_title',
+                                       'ORDER BY' => 'ar_namespace,ar_title',
+                                       'LIMIT' => 100,
+                               )
+                       )
+               );
+       }
+       
        /**
         * List the revisions of the given page. Returns result wrapper with
         * (ar_minor_edit, ar_timestamp, ar_user, ar_user_text, ar_comment) fields.
@@ -57,9 +98,9 @@ class PageArchive {
         * @return ResultWrapper
         */
        function listRevisions() {
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr = wfGetDB( DB_SLAVE );
                $res = $dbr->select( 'archive',
-                       array( 'ar_minor_edit', 'ar_timestamp', 'ar_user', 'ar_user_text', 'ar_comment' ),
+                       array( 'ar_minor_edit', 'ar_timestamp', 'ar_user', 'ar_user_text', 'ar_comment', 'ar_len' ),
                        array( 'ar_namespace' => $this->title->getNamespace(),
                               'ar_title' => $this->title->getDBkey() ),
                        'PageArchive::listRevisions',
@@ -74,11 +115,11 @@ class PageArchive {
         * if not a file page.
         *
         * @return ResultWrapper
-        * @fixme Does this belong in Image for fuller encapsulation?
+        * @todo Does this belong in Image for fuller encapsulation?
         */
        function listFiles() {
                if( $this->title->getNamespace() == NS_IMAGE ) {
-                       $dbr =& wfGetDB( DB_SLAVE );
+                       $dbr = wfGetDB( DB_SLAVE );
                        $res = $dbr->select( 'filearchive',
                                array(
                                        'fa_id',
@@ -91,7 +132,7 @@ class PageArchive {
                                        'fa_user',
                                        'fa_user_text',
                                        'fa_timestamp' ),
-                               array( 'fa_name' => $this->title->getDbKey() ),
+                               array( 'fa_name' => $this->title->getDBkey() ),
                                __METHOD__,
                                array( 'ORDER BY' => 'fa_timestamp DESC' ) );
                        $ret = $dbr->resultObject( $res );
@@ -119,7 +160,7 @@ class PageArchive {
         * @return Revision
         */
        function getRevision( $timestamp ) {
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr = wfGetDB( DB_SLAVE );
                $row = $dbr->selectRow( 'archive',
                        array(
                                'ar_rev_id',
@@ -130,9 +171,10 @@ class PageArchive {
                                'ar_timestamp',
                                'ar_minor_edit',
                                'ar_flags',
-                               'ar_text_id' ),
+                               'ar_text_id',
+                               'ar_len' ),
                        array( 'ar_namespace' => $this->title->getNamespace(),
-                              'ar_title' => $this->title->getDbkey(),
+                              'ar_title' => $this->title->getDBkey(),
                               'ar_timestamp' => $dbr->timestamp( $timestamp ) ),
                        __METHOD__ );
                if( $row ) {
@@ -152,6 +194,59 @@ class PageArchive {
                        return null;
                }
        }
+       
+       /**
+        * Return the most-previous revision, either live or deleted, against
+        * the deleted revision given by timestamp.
+        *
+        * May produce unexpected results in case of history merges or other
+        * unusual time issues.
+        *
+        * @param string $timestamp
+        * @return Revision or null
+        */
+       function getPreviousRevision( $timestamp ) {
+               $dbr = wfGetDB( DB_SLAVE );
+               
+               // Check the previous deleted revision...
+               $row = $dbr->selectRow( 'archive',
+                       'ar_timestamp',
+                       array( 'ar_namespace' => $this->title->getNamespace(),
+                              'ar_title' => $this->title->getDBkey(),
+                              'ar_timestamp < ' .
+                                               $dbr->addQuotes( $dbr->timestamp( $timestamp ) ) ),
+                       __METHOD__,
+                       array(
+                               'ORDER BY' => 'ar_timestamp DESC',
+                               'LIMIT' => 1 ) );
+               $prevDeleted = $row ? wfTimestamp( TS_MW, $row->ar_timestamp ) : false;
+               
+               $row = $dbr->selectRow( array( 'page', 'revision' ),
+                       array( 'rev_id', 'rev_timestamp' ),
+                       array(
+                               'page_namespace' => $this->title->getNamespace(),
+                               'page_title' => $this->title->getDBkey(),
+                               'page_id = rev_page',
+                               'rev_timestamp < ' .
+                                               $dbr->addQuotes( $dbr->timestamp( $timestamp ) ) ),
+                       __METHOD__,
+                       array(
+                               'ORDER BY' => 'rev_timestamp DESC',
+                               'LIMIT' => 1 ) );
+               $prevLive = $row ? wfTimestamp( TS_MW, $row->rev_timestamp ) : false;
+               $prevLiveId = $row ? intval( $row->rev_id ) : null;
+               
+               if( $prevLive && $prevLive > $prevDeleted ) {
+                       // Most prior revision was live
+                       return Revision::newFromId( $prevLiveId );
+               } elseif( $prevDeleted ) {
+                       // Most prior revision was deleted
+                       return $this->getRevision( $prevDeleted );
+               } else {
+                       // No prior revision on this page.
+                       return null;
+               }
+       }
 
        /**
         * Get the text from an archive row containing ar_text, ar_flags and ar_text_id
@@ -163,7 +258,7 @@ class PageArchive {
                        return Revision::getRevisionText( $row, "ar_" );
                } else {
                        // New-style: keyed to the text storage backend.
-                       $dbr =& wfGetDB( DB_SLAVE );
+                       $dbr = wfGetDB( DB_SLAVE );
                        $text = $dbr->selectRow( 'text',
                                array( 'old_text', 'old_flags' ),
                                array( 'old_id' => $row->ar_text_id ),
@@ -182,7 +277,7 @@ class PageArchive {
         * @return string
         */
        function getLastRevisionText() {
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr = wfGetDB( DB_SLAVE );
                $row = $dbr->selectRow( 'archive',
                        array( 'ar_text', 'ar_flags', 'ar_text_id' ),
                        array( 'ar_namespace' => $this->title->getNamespace(),
@@ -201,7 +296,7 @@ class PageArchive {
         * @return bool
         */
        function isDeleted() {
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr = wfGetDB( DB_SLAVE );
                $n = $dbr->selectField( 'archive', 'COUNT(ar_title)',
                        array( 'ar_namespace' => $this->title->getNamespace(),
                               'ar_title' => $this->title->getDBkey() ) );
@@ -217,7 +312,8 @@ class PageArchive {
         * @param string $comment
         * @param array $fileVersions
         *
-        * @return true on success.
+        * @return array(number of file revisions restored, number of image revisions restored, log message)
+        * on success, false on failure
         */
        function undelete( $timestamps, $comment = '', $fileVersions = array() ) {
                // If both the set of text revisions and file revisions are empty,
@@ -228,31 +324,34 @@ class PageArchive {
                $restoreFiles = $restoreAll || !empty( $fileVersions );
                
                if( $restoreFiles && $this->title->getNamespace() == NS_IMAGE ) {
-                       $img = new Image( $this->title );
-                       $filesRestored = $img->restore( $fileVersions );
+                       $img = wfLocalFile( $this->title );
+                       $this->fileStatus = $img->restore( $fileVersions );
+                       $filesRestored = $this->fileStatus->successCount;
                } else {
                        $filesRestored = 0;
                }
                
                if( $restoreText ) {
                        $textRestored = $this->undeleteRevisions( $timestamps );
+                       if($textRestored === false) // It must be one of UNDELETE_*
+                               return false;
                } else {
                        $textRestored = 0;
                }
-               
+
                // Touch the log!
                global $wgContLang;
                $log = new LogPage( 'delete' );
                
                if( $textRestored && $filesRestored ) {
-                       $reason = wfMsgForContent( 'undeletedrevisions-files',
+                       $reason = wfMsgExt( 'undeletedrevisions-files', array( 'content', 'parsemag' ),
                                $wgContLang->formatNum( $textRestored ),
                                $wgContLang->formatNum( $filesRestored ) );
                } elseif( $textRestored ) {
-                       $reason = wfMsgForContent( 'undeletedrevisions',
+                       $reason = wfMsgExt( 'undeletedrevisions', array( 'content', 'parsemag' ),
                                $wgContLang->formatNum( $textRestored ) );
                } elseif( $filesRestored ) {
-                       $reason = wfMsgForContent( 'undeletedfiles',
+                       $reason = wfMsgExt( 'undeletedfiles', array( 'content', 'parsemag' ),
                                $wgContLang->formatNum( $filesRestored ) );
                } else {
                        wfDebug( "Undelete: nothing undeleted...\n" );
@@ -262,8 +361,8 @@ class PageArchive {
                if( trim( $comment ) != '' )
                        $reason .= ": {$comment}";
                $log->addEntry( 'restore', $this->title, $reason );
-               
-               return true;
+
+               return array($textRestored, $filesRestored, $reason);
        }
        
        /**
@@ -275,21 +374,19 @@ class PageArchive {
         * @param string $comment
         * @param array $fileVersions
         *
-        * @return int number of revisions restored
+        * @return mixed number of revisions restored or false on failure
         */
        private function undeleteRevisions( $timestamps ) {
-               global $wgDBtype;
+               if ( wfReadOnly() )
+                       return false;
 
                $restoreAll = empty( $timestamps );
                
-               $dbw =& wfGetDB( DB_MASTER );
-               $page = $dbw->tableName( 'archive' );
+               $dbw = wfGetDB( DB_MASTER );
 
                # Does this page already exist? We'll have to update it...
                $article = new Article( $this->title );
-               $options = ( $wgDBtype == 'postgres' )
-                       ? '' // pg doesn't support this?
-                       : 'FOR UPDATE';
+               $options = 'FOR UPDATE';
                $page = $dbw->selectRow( 'page',
                        array( 'page_id', 'page_latest' ),
                        array( 'page_namespace' => $this->title->getNamespace(),
@@ -333,7 +430,9 @@ class PageArchive {
                                'ar_timestamp',
                                'ar_minor_edit',
                                'ar_flags',
-                               'ar_text_id' ),
+                               'ar_text_id',
+                               'ar_page_id',
+                               'ar_len' ),
                        /* WHERE */ array(
                                'ar_namespace' => $this->title->getNamespace(),
                                'ar_title'     => $this->title->getDBkey(),
@@ -373,28 +472,36 @@ class PageArchive {
                                'timestamp'  => $row->ar_timestamp,
                                'minor_edit' => $row->ar_minor_edit,
                                'text_id'    => $row->ar_text_id,
+                               'len'            => $row->ar_len
                                ) );
                        $revision->insertOn( $dbw );
                        $restored++;
+                       
+                       wfRunHooks( 'ArticleRevisionUndeleted', array( &$this->title, $revision, $row->ar_page_id ) );
                }
+               // Was anything restored at all?
+               if($restored == 0)
+                       return 0;
 
                if( $revision ) {
-                       # FIXME: Update latest if newer as well...
-                       if( $newid ) {
-                               // Attach the latest revision to the page...
-                               $article->updateRevisionOn( $dbw, $revision, $previousRevId );
-                               
+                       // Attach the latest revision to the page...
+                       $wasnew = $article->updateIfNewerOn( $dbw, $revision, $previousRevId );
+
+                       if( $newid || $wasnew ) {
                                // Update site stats, link tables, etc
                                $article->createUpdates( $revision );
                        }
 
                        if( $newid ) {
+                               wfRunHooks( 'ArticleUndelete', array( &$this->title, true ) );
                                Article::onArticleCreate( $this->title );
                        } else {
+                               wfRunHooks( 'ArticleUndelete', array( &$this->title, false ) );
                                Article::onArticleEdit( $this->title );
                        }
                } else {
-                       # Something went terribly wrong!
+                       // Revision couldn't be created. This is very weird
+                       return self::UNDELETE_UNKNOWNERR;
                }
 
                # Now that it's safely stored, take it out of the archive
@@ -408,21 +515,23 @@ class PageArchive {
                return $restored;
        }
 
+       function getFileStatus() { return $this->fileStatus; }
 }
 
 /**
- *
- * @package MediaWiki
- * @subpackage SpecialPage
+ * The HTML form for Special:Undelete, which allows users with the appropriate
+ * permissions to view and restore deleted content.
+ * @addtogroup SpecialPage
  */
 class UndeleteForm {
        var $mAction, $mTarget, $mTimestamp, $mRestore, $mTargetObj;
        var $mTargetTimestamp, $mAllowed, $mComment;
 
-       function UndeleteForm( &$request, $par = "" ) {
+       function UndeleteForm( $request, $par = "" ) {
                global $wgUser;
                $this->mAction = $request->getVal( 'action' );
                $this->mTarget = $request->getVal( 'target' );
+               $this->mSearchPrefix = $request->getText( 'prefix' );
                $time = $request->getVal( 'timestamp' );
                $this->mTimestamp = $time ? wfTimestamp( TS_MW, $time ) : '';
                $this->mFile = $request->getVal( 'file' );
@@ -431,12 +540,13 @@ class UndeleteForm {
                        $wgUser->matchEditToken( $request->getVal( 'wpEditToken' ) );
                $this->mRestore = $request->getCheck( 'restore' ) && $posted;
                $this->mPreview = $request->getCheck( 'preview' ) && $posted;
+               $this->mDiff = $request->getCheck( 'diff' );
                $this->mComment = $request->getText( 'wpComment' );
                
                if( $par != "" ) {
                        $this->mTarget = $par;
                }
-               if ( $wgUser->isAllowed( 'delete' ) && !$wgUser->isBlocked() ) {
+               if ( $wgUser->isAllowed( 'undelete' ) && !$wgUser->isBlocked() ) {
                        $this->mAllowed = true;
                } else {
                        $this->mAllowed = false;
@@ -467,9 +577,23 @@ class UndeleteForm {
        }
 
        function execute() {
-
+               global $wgOut;
+               if ( $this->mAllowed ) {
+                       $wgOut->setPagetitle( wfMsg( "undeletepage" ) );
+               } else {
+                       $wgOut->setPagetitle( wfMsg( "viewdeletedpage" ) );
+               }
+               
                if( is_null( $this->mTargetObj ) ) {
-                       return $this->showList();
+                       $this->showSearchForm();
+
+                       # List undeletable articles
+                       if( $this->mSearchPrefix ) {
+                               $result = PageArchive::listPagesByPrefix(
+                                       $this->mSearchPrefix );
+                               $this->showList( $result );
+                       }
+                       return;
                }
                if( $this->mTimestamp !== '' ) {
                        return $this->showRevision( $this->mTimestamp );
@@ -483,17 +607,35 @@ class UndeleteForm {
                return $this->showHistory();
        }
 
-       /* private */ function showList() {
-               global $wgLang, $wgContLang, $wgUser, $wgOut;
-
-               # List undeletable articles
-               $result = PageArchive::listAllPages();
+       function showSearchForm() {
+               global $wgOut, $wgScript;
+               $wgOut->addWikiText( wfMsg( 'undelete-header' ) );
+               
+               $wgOut->addHtml(
+                       Xml::openElement( 'form', array(
+                               'method' => 'get',
+                               'action' => $wgScript ) ) .
+                       '<fieldset>' .
+                       Xml::element( 'legend', array(),
+                               wfMsg( 'undelete-search-box' ) ) .
+                       Xml::hidden( 'title',
+                               SpecialPage::getTitleFor( 'Undelete' )->getPrefixedDbKey() ) .
+                       Xml::inputLabel( wfMsg( 'undelete-search-prefix' ),
+                               'prefix', 'prefix', 20,
+                               $this->mSearchPrefix ) .
+                       Xml::submitButton( wfMsg( 'undelete-search-submit' ) ) .
+                       '</fieldset>' .
+                       '</form>' );
+       }
 
-               if ( $this->mAllowed ) {
-                       $wgOut->setPagetitle( wfMsg( "undeletepage" ) );
-               } else {
-                       $wgOut->setPagetitle( wfMsg( "viewdeletedpage" ) );
+       /* private */ function showList( $result ) {
+               global $wgLang, $wgContLang, $wgUser, $wgOut;
+               
+               if( $result->numRows() == 0 ) {
+                       $wgOut->addWikiText( wfMsg( 'undelete-no-results' ) );
+                       return;
                }
+
                $wgOut->addWikiText( wfMsg( "undeletepagetext" ) );
 
                $sk = $wgUser->getSkin();
@@ -502,7 +644,10 @@ class UndeleteForm {
                while( $row = $result->fetchObject() ) {
                        $title = Title::makeTitleSafe( $row->ar_namespace, $row->ar_title );
                        $link = $sk->makeKnownLinkObj( $undelete, htmlspecialchars( $title->getPrefixedText() ), 'target=' . $title->getPrefixedUrl() );
-                       $revs = wfMsgHtml( 'undeleterevisions', $wgLang->formatNum( $row->count ) );
+                       #$revs = wfMsgHtml( 'undeleterevisions', $wgLang->formatNum( $row->count ) );
+                       $revs = wfMsgExt( 'undeleterevisions',
+                               array( 'parseinline' ),
+                               $wgLang->formatNum( $row->count ) );
                        $wgOut->addHtml( "<li>{$link} ({$revs})</li>\n" );
                }
                $result->free();
@@ -521,27 +666,47 @@ class UndeleteForm {
                $archive = new PageArchive( $this->mTargetObj );
                $rev = $archive->getRevision( $timestamp );
                
-               $wgOut->setPageTitle( wfMsg( 'undeletepage' ) );
-               $link = $skin->makeKnownLinkObj( $self, htmlspecialchars( $this->mTargetObj->getPrefixedText() ),
-                                       'target=' . $this->mTargetObj->getPrefixedUrl() );
-               $wgOut->addHtml( '<p>' . wfMsgHtml( 'undelete-revision', $link,
-                       htmlspecialchars( $wgLang->timeAndDate( $timestamp ) ) ) . '</p>' ); 
-               
                if( !$rev ) {
-                       $wgOut->addWikiText( wfMsg( 'undeleterevision-missing' ) );
+                       $wgOut->addWikiTexT( wfMsg( 'undeleterevision-missing' ) );
                        return;
                }
                
+               $wgOut->setPageTitle( wfMsg( 'undeletepage' ) );
+               
+               $link = $skin->makeKnownLinkObj(
+                       SpecialPage::getTitleFor( 'Undelete', $this->mTargetObj->getPrefixedDBkey() ),
+                       htmlspecialchars( $this->mTargetObj->getPrefixedText() )
+               );
+               $time = htmlspecialchars( $wgLang->timeAndDate( $timestamp, true ) );
+               $user = $skin->userLink( $rev->getUser(), $rev->getUserText() )
+                       . $skin->userToolLinks( $rev->getUser(), $rev->getUserText() );
+
+               if( $this->mDiff ) {
+                       $previousRev = $archive->getPreviousRevision( $timestamp );
+                       if( $previousRev ) {
+                               $this->showDiff( $previousRev, $rev );
+                               if( $wgUser->getOption( 'diffonly' ) ) {
+                                       return;
+                               } else {
+                                       $wgOut->addHtml( '<hr />' );
+                               }
+                       } else {
+                               $wgOut->addHtml( wfMsgHtml( 'undelete-nodiff' ) );
+                       }
+               }
+               
+               $wgOut->addHtml( '<p>' . wfMsgHtml( 'undelete-revision', $link, $time, $user ) . '</p>' );
+               
                wfRunHooks( 'UndeleteShowRevision', array( $this->mTargetObj, $rev ) );
                
                if( $this->mPreview ) {
                        $wgOut->addHtml( "<hr />\n" );
-                       $wgOut->addWikiTextTitle( $rev->getText(), $archive->title, false );
+                       $wgOut->addWikiTextTitleTidy( $rev->getText(), $this->mTargetObj, false );
                }
 
                $wgOut->addHtml(
                        wfElement( 'textarea', array(
-                                       'readonly' => true,
+                                       'readonly' => 'readonly',
                                        'cols' => intval( $wgUser->getOption( 'cols' ) ),
                                        'rows' => intval( $wgUser->getOption( 'rows' ) ) ),
                                $rev->getText() . "\n" ) .
@@ -562,16 +727,83 @@ class UndeleteForm {
                                'name' => 'wpEditToken',
                                'value' => $wgUser->editToken() ) ) .
                        wfElement( 'input', array(
-                               'type' => 'hidden',
+                               'type' => 'submit',
                                'name' => 'preview',
-                               'value' => '1' ) ) .
+                               'value' => wfMsg( 'showpreview' ) ) ) .
                        wfElement( 'input', array(
+                               'name' => 'diff',
                                'type' => 'submit',
-                               'value' => wfMsg( 'showpreview' ) ) ) .
+                               'value' => wfMsg( 'showdiff' ) ) ) .
                        wfCloseElement( 'form' ) .
                        wfCloseElement( 'div' ) );
        }
        
+       /**
+        * Build a diff display between this and the previous either deleted
+        * or non-deleted edit.
+        * @param Revision $previousRev
+        * @param Revision $currentRev
+        * @return string HTML
+        */
+       function showDiff( $previousRev, $currentRev ) {
+               global $wgOut, $wgUser;
+               
+               $diffEngine = new DifferenceEngine();
+               $diffEngine->showDiffStyle();
+               $wgOut->addHtml(
+                       "<div>" .
+                       "<table border='0' width='98%' cellpadding='0' cellspacing='4' class='diff'>" .
+                       "<col class='diff-marker' />" .
+                       "<col class='diff-content' />" .
+                       "<col class='diff-marker' />" .
+                       "<col class='diff-content' />" .
+                       "<tr>" .
+                               "<td colspan='2' width='50%' align='center' class='diff-otitle'>" .
+                               $this->diffHeader( $previousRev ) .
+                               "</td>" .
+                               "<td colspan='2' width='50%' align='center' class='diff-ntitle'>" .
+                               $this->diffHeader( $currentRev ) .
+                               "</td>" .
+                       "</tr>" .
+                       $diffEngine->generateDiffBody(
+                               $previousRev->getText(), $currentRev->getText() ) .
+                       "</table>" .
+                       "</div>\n" );
+
+       }
+       
+       private function diffHeader( $rev ) {
+               global $wgUser, $wgLang, $wgLang;
+               $sk = $wgUser->getSkin();
+               $isDeleted = !( $rev->getId() && $rev->getTitle() );
+               if( $isDeleted ) {
+                       /// @fixme $rev->getTitle() is null for deleted revs...?
+                       $targetPage = SpecialPage::getTitleFor( 'Undelete' );
+                       $targetQuery = 'target=' .
+                               $this->mTargetObj->getPrefixedUrl() .
+                               '&timestamp=' .
+                               wfTimestamp( TS_MW, $rev->getTimestamp() );
+               } else {
+                       /// @fixme getId() may return non-zero for deleted revs...
+                       $targetPage = $rev->getTitle();
+                       $targetQuery = 'oldid=' . $rev->getId();
+               }
+               return
+                       '<div id="mw-diff-otitle1"><strong>' .
+                               $sk->makeLinkObj( $targetPage,
+                                       wfMsgHtml( 'revisionasof',
+                                               $wgLang->timeanddate( $rev->getTimestamp(), true ) ),
+                                       $targetQuery ) .
+                               ( $isDeleted ? ' ' . wfMsgHtml( 'deletedrev' ) : '' ) .
+                       '</strong></div>' .
+                       '<div id="mw-diff-otitle2">' .
+                               $sk->revUserTools( $rev ) . '<br/>' .
+                       '</div>' .
+                       '<div id="mw-diff-otitle3">' .
+                               $sk->revComment( $rev ) . '<br/>' .
+                       '</div>';
+       }
+       
        /**
         * Show a deleted file version requested by the visitor.
         */
@@ -592,7 +824,7 @@ class UndeleteForm {
        }
 
        /* private */ function showHistory() {
-               global $wgLang, $wgUser, $wgOut;
+               global $wgLang, $wgContLang, $wgUser, $wgOut;
 
                $sk = $wgUser->getSkin();
                if ( $this->mAllowed ) {
@@ -618,10 +850,10 @@ class UndeleteForm {
                # List all stored revisions
                $revisions = $archive->listRevisions();
                $files = $archive->listFiles();
-               
+
                $haveRevisions = $revisions && $revisions->numRows() > 0;
                $haveFiles = $files && $files->numRows() > 0;
-               
+
                # Batch existence check on user and talk pages
                if( $haveRevisions ) {
                        $batch = new LinkBatch();
@@ -646,7 +878,7 @@ class UndeleteForm {
                        $titleObj = SpecialPage::getTitleFor( "Undelete" );
                        $action = $titleObj->getLocalURL( "action=submit" );
                        # Start the form here
-                       $top = wfOpenElement( 'form', array( 'method' => 'post', 'action' => $action, 'id' => 'undelete' ) );
+                       $top = Xml::openElement( 'form', array( 'method' => 'post', 'action' => $action, 'id' => 'undelete' ) );
                        $wgOut->addHtml( $top );
                }
 
@@ -655,45 +887,93 @@ class UndeleteForm {
                $logViewer = new LogViewer(
                        new LogReader(
                                new FauxRequest(
-                                       array( 'page' => $this->mTargetObj->getPrefixedText(),
-                                                  'type' => 'delete' ) ) ) );
+                                       array( 
+                                               'page' => $this->mTargetObj->getPrefixedText(),
+                                               'type' => 'delete' 
+                                       ) 
+                               )
+                       ), LogViewer::NO_ACTION_LINK
+               );
                $logViewer->showList( $wgOut );
-               
+
                if( $this->mAllowed && ( $haveRevisions || $haveFiles ) ) {
                        # Format the user-visible controls (comment field, submission button)
                        # in a nice little table
-                       $table = '<fieldset><table><tr>';
-                       $table .= '<td colspan="2">' . wfMsgWikiHtml( 'undeleteextrahelp' ) . '</td></tr><tr>';
-                       $table .= '<td align="right"><strong>' . wfMsgHtml( 'undeletecomment' ) . '</strong></td>';
-                       $table .= '<td>' . wfInput( 'wpComment', 50, $this->mComment ) . '</td>';
-                       $table .= '</tr><tr><td>&nbsp;</td><td>';
-                       $table .= wfSubmitButton( wfMsg( 'undeletebtn' ), array( 'name' => 'restore' ) );
-                       $table .= wfElement( 'input', array( 'type' => 'reset', 'value' => wfMsg( 'undeletereset' ) ) );
-                       $table .= '</td></tr></table></fieldset>';
+                       $align = $wgContLang->isRtl() ? 'left' : 'right';
+                       $table =
+                               Xml::openElement( 'fieldset' ) .
+                               Xml::openElement( 'table' ) .
+                                       "<tr>
+                                               <td colspan='2'>" .
+                                                       wfMsgWikiHtml( 'undeleteextrahelp' ) .
+                                               "</td>
+                                       </tr>
+                                       <tr>
+                                               <td align='$align'>" .
+                                                       Xml::label( wfMsg( 'undeletecomment' ), 'wpComment' ) .
+                                               "</td>
+                                               <td>" .
+                                                       Xml::input( 'wpComment', 50, $this->mComment ) .
+                                               "</td>
+                                       </tr>
+                                       <tr>
+                                               <td>&nbsp;</td>
+                                               <td>" .
+                                                       Xml::submitButton( wfMsg( 'undeletebtn' ), array( 'name' => 'restore', 'id' => 'mw-undelete-submit' ) ) .
+                                                       Xml::element( 'input', array( 'type' => 'reset', 'value' => wfMsg( 'undeletereset' ), 'id' => 'mw-undelete-reset' ) ) .
+                                               "</td>
+                                       </tr>" .
+                               Xml::closeElement( 'table' ) .
+                               Xml::closeElement( 'fieldset' );
+
                        $wgOut->addHtml( $table );
                }
-       
+
                $wgOut->addHTML( "<h2>" . htmlspecialchars( wfMsg( "history" ) ) . "</h2>\n" );
-               
+
                if( $haveRevisions ) {
                        # The page's stored (deleted) history:
                        $wgOut->addHTML("<ul>");
                        $target = urlencode( $this->mTarget );
+                       $remaining = $revisions->numRows();
+                       $earliestLiveTime = $this->getEarliestTime( $this->mTargetObj );
+                       
                        while( $row = $revisions->fetchObject() ) {
+                               $remaining--;
                                $ts = wfTimestamp( TS_MW, $row->ar_timestamp );
                                if ( $this->mAllowed ) {
-                                       $checkBox = wfCheck( "ts$ts" );
+                                       $checkBox = Xml::check( "ts$ts" );
                                        $pageLink = $sk->makeKnownLinkObj( $titleObj,
                                                $wgLang->timeanddate( $ts, true ),
                                                "target=$target&timestamp=$ts" );
+                                       if( ($remaining > 0) ||
+                                                       ($earliestLiveTime && $ts > $earliestLiveTime ) ) {
+                                               $diffLink = '(' .
+                                                       $sk->makeKnownLinkObj( $titleObj,
+                                                               wfMsgHtml( 'diff' ),
+                                                               "target=$target&timestamp=$ts&diff=prev" ) .
+                                                       ')';
+                                       } else {
+                                               // No older revision to diff against
+                                               $diffLink = '';
+                                       }
                                } else {
                                        $checkBox = '';
                                        $pageLink = $wgLang->timeanddate( $ts, true );
+                                       $diffLink = '';
                                }
                                $userLink = $sk->userLink( $row->ar_user, $row->ar_user_text ) . $sk->userToolLinks( $row->ar_user, $row->ar_user_text );
+                               $stxt = '';
+                               if (!is_null($size = $row->ar_len)) {
+                                       if ($size == 0) {
+                                               $stxt = wfMsgHtml('historyempty');
+                                       } else {
+                                               $stxt = wfMsgHtml('historysize', $wgLang->formatNum( $size ) );
+                                       }
+                               }
                                $comment = $sk->commentBlock( $row->ar_comment );
-                               $wgOut->addHTML( "<li>$checkBox $pageLink . . $userLink $comment</li>\n" );
-       
+                               $wgOut->addHTML( "<li>$checkBox $pageLink $diffLink . . $userLink $stxt $comment</li>\n" );
+
                        }
                        $revisions->free();
                        $wgOut->addHTML("</ul>");
@@ -701,14 +981,13 @@ class UndeleteForm {
                        $wgOut->addWikiText( wfMsg( "nohistory" ) );
                }
 
-               
                if( $haveFiles ) {
-                       $wgOut->addHtml( "<h2>" . wfMsgHtml( 'imghistory' ) . "</h2>\n" );
+                       $wgOut->addHtml( "<h2>" . wfMsgHtml( 'filehist' ) . "</h2>\n" );
                        $wgOut->addHtml( "<ul>" );
                        while( $row = $files->fetchObject() ) {
                                $ts = wfTimestamp( TS_MW, $row->fa_timestamp );
                                if ( $this->mAllowed && $row->fa_storage_key ) {
-                                       $checkBox = wfCheck( "fileid" . $row->fa_id );
+                                       $checkBox = Xml::check( "fileid" . $row->fa_id );
                                        $key = urlencode( $row->fa_storage_key );
                                        $target = urlencode( $this->mTarget );
                                        $pageLink = $sk->makeKnownLinkObj( $titleObj,
@@ -732,19 +1011,36 @@ class UndeleteForm {
                        $files->free();
                        $wgOut->addHTML( "</ul>" );
                }
-               
+
                if ( $this->mAllowed ) {
                        # Slip in the hidden controls here
-                       $misc  = wfHidden( 'target', $this->mTarget );
-                       $misc .= wfHidden( 'wpEditToken', $wgUser->editToken() );
-                       $wgOut->addHtml( $misc . '</form>' );
+                       $misc  = Xml::hidden( 'target', $this->mTarget );
+                       $misc .= Xml::hidden( 'wpEditToken', $wgUser->editToken() );
+                       $misc .= Xml::closeElement( 'form' );
+                       $wgOut->addHtml( $misc );
                }
 
                return true;
        }
+       
+       private function getEarliestTime( $title ) {
+               $dbr = wfGetDB( DB_SLAVE );
+               if( $title->exists() ) {
+                       $min = $dbr->selectField( 'revision',
+                               'MIN(rev_timestamp)',
+                               array( 'rev_page' => $title->getArticleId() ),
+                               __METHOD__ );
+                       return wfTimestampOrNull( TS_MW, $min );
+               }
+               return null;
+       }
 
        function undelete() {
                global $wgOut, $wgUser;
+               if ( wfReadOnly() ) {
+                       $wgOut->readOnlyPage();
+                       return;
+               }
                if( !is_null( $this->mTargetObj ) ) {
                        $archive = new PageArchive( $this->mTargetObj );
                        
@@ -752,17 +1048,23 @@ class UndeleteForm {
                                $this->mTargetTimestamp,
                                $this->mComment,
                                $this->mFileVersions );
-                       
-                       if( $ok ) {
-                               $skin =& $wgUser->getSkin();
+
+                       if( is_array($ok) ) {
+                               $skin = $wgUser->getSkin();
                                $link = $skin->makeKnownLinkObj( $this->mTargetObj );
                                $wgOut->addHtml( wfMsgWikiHtml( 'undeletedpage', $link ) );
-                               return true;
+                       } else {
+                               $wgOut->showFatalError( wfMsg( "cannotundelete" ) );
                        }
+
+                       // Show file deletion warnings and errors
+                       $status = $archive->getFileStatus();
+                       if ( $status && !$status->isGood() ) {
+                               $wgOut->addWikiText( $status->getWikiText( 'undelete-error-short', 'undelete-error-long' ) );
+                       }
+               } else {
+                       $wgOut->showFatalError( wfMsg( "cannotundelete" ) );
                }
-               $wgOut->showFatalError( wfMsg( "cannotundelete" ) );
                return false;
        }
 }
-
-?>