includes/diff/DifferenceEngine.php

   1 <?php
   2 /**
   3  * User interface for the difference engine
   4  *
   5  * @file
   6  * @ingroup DifferenceEngine
   7  */
   8
   9 /**
  10  * Constant to indicate diff cache compatibility.
  11  * Bump this when changing the diff formatting in a way that
  12  * fixes important bugs or such to force cached diff views to
  13  * clear.
  14  */
  15 define( 'MW_DIFF_VERSION', '1.11a' );
  16
  17 /**
  18  * @todo document
  19  * @ingroup DifferenceEngine
  20  */
  21 class DifferenceEngine {
  22         /**#@+
  23          * @private
  24          */
  25         var $mOldid, $mNewid;
  26         var $mOldtitle, $mNewtitle, $mPagetitle;
  27         var $mOldtext, $mNewtext;
  28
  29         /**
  30          * @var Title
  31          */
  32         var $mOldPage, $mNewPage, $mTitle;
  33         var $mRcidMarkPatrolled;
  34
  35         /**
  36          * @var Revision
  37          */
  38         var $mOldRev, $mNewRev;
  39         var $mRevisionsLoaded = false; // Have the revisions been loaded
  40         var $mTextLoaded = 0; // How many text blobs have been loaded, 0, 1 or 2?
  41         var $mCacheHit = false; // Was the diff fetched from cache?
  42
  43         /**
  44          * Set this to true to add debug info to the HTML output.
  45          * Warning: this may cause RSS readers to spuriously mark articles as "new"
  46          * (bug 20601)
  47          */
  48         var $enableDebugComment = false;
  49
  50         // If true, line X is not displayed when X is 1, for example to increase
  51         // readability and conserve space with many small diffs.
  52         protected $mReducedLineNumbers = false;
  53
  54         protected $unhide = false; # show rev_deleted content if allowed
  55         /**#@-*/
  56
  57         /**
  58          * Constructor
  59          * @param $titleObj Title object that the diff is associated with
  60          * @param $old Integer: old ID we want to show and diff with.
  61          * @param $new String: either 'prev' or 'next'.
  62          * @todo FIXME: $rcid ???
  63          * @param $rcid Integer: ??? FIXME (default 0)
  64          * @param $refreshCache boolean If set, refreshes the diff cache
  65          * @param $unhide boolean If set, allow viewing deleted revs
  66          */
  67         function __construct( $titleObj = null, $old = 0, $new = 0, $rcid = 0,
  68                 $refreshCache = false, $unhide = false )
  69         {
  70                 if ( $titleObj ) {
  71                         $this->mTitle = $titleObj;
  72                 } else {
  73                         global $wgTitle;
  74                         $this->mTitle = $wgTitle; // @TODO: get rid of this
  75                 }
  76                 wfDebug( "DifferenceEngine old '$old' new '$new' rcid '$rcid'\n" );
  77
  78                 if ( 'prev' === $new ) {
  79                         # Show diff between revision $old and the previous one.
  80                         # Get previous one from DB.
  81                         $this->mNewid = intval( $old );
  82                         $this->mOldid = $this->mTitle->getPreviousRevisionID( $this->mNewid );
  83                 } elseif ( 'next' === $new ) {
  84                         # Show diff between revision $old and the next one.
  85                         # Get next one from DB.
  86                         $this->mOldid = intval( $old );
  87                         $this->mNewid = $this->mTitle->getNextRevisionID( $this->mOldid );
  88                         if ( false === $this->mNewid ) {
  89                                 # if no result, NewId points to the newest old revision. The only newer
  90                                 # revision is cur, which is "0".
  91                                 $this->mNewid = 0;
  92                         }
  93                 } else {
  94                         $this->mOldid = intval( $old );
  95                         $this->mNewid = intval( $new );
  96                         wfRunHooks( 'NewDifferenceEngine', array( &$titleObj, &$this->mOldid, &$this->mNewid, $old, $new ) );
  97                 }
  98                 $this->mRcidMarkPatrolled = intval( $rcid );  # force it to be an integer
  99                 $this->mRefreshCache = $refreshCache;
 100                 $this->unhide = $unhide;
 101         }
 102
 103         function setReducedLineNumbers( $value = true ) {
 104                 $this->mReducedLineNumbers = $value;
 105         }
 106
 107         function getTitle() {
 108                 return $this->mTitle;
 109         }
 110
 111         function wasCacheHit() {
 112                 return $this->mCacheHit;
 113         }
 114
 115         function getOldid() {
 116                 return $this->mOldid;
 117         }
 118
 119         function getNewid() {
 120                 return $this->mNewid;
 121         }
 122
 123         /**
 124          * Look up a special:Undelete link to the given deleted revision id,
 125          * as a workaround for being unable to load deleted diffs in currently.
 126          *
 127          * @param int $id revision ID
 128          * @return mixed URL or false
 129          */
 130         function deletedLink( $id ) {
 131                 global $wgUser;
 132                 if ( $wgUser->isAllowed( 'deletedhistory' ) ) {
 133                         $dbr = wfGetDB( DB_SLAVE );
 134                         $row = $dbr->selectRow('archive', '*',
 135                                 array( 'ar_rev_id' => $id ),
 136                                 __METHOD__ );
 137                         if ( $row ) {
 138                                 $rev = Revision::newFromArchiveRow( $row );
 139                                 $title = Title::makeTitleSafe( $row->ar_namespace, $row->ar_title );
 140                                 return SpecialPage::getTitleFor( 'Undelete' )->getFullURL( array(
 141                                         'target' => $title->getPrefixedText(),
 142                                         'timestamp' => $rev->getTimestamp()
 143                                 ));
 144                         }
 145                 }
 146                 return false;
 147         }
 148
 149         /**
 150          * Build a wikitext link toward a deleted revision, if viewable.
 151          *
 152          * @param int $id revision ID
 153          * @return string wikitext fragment
 154          */
 155         function deletedIdMarker( $id ) {
 156                 $link = $this->deletedLink( $id );
 157                 if ( $link ) {
 158                         return "[$link $id]";
 159                 } else {
 160                         return $id;
 161                 }
 162         }
 163
 164         function showDiffPage( $diffOnly = false ) {
 165                 global $wgUser, $wgOut, $wgUseExternalEditor, $wgUseRCPatrol;
 166                 wfProfileIn( __METHOD__ );
 167
 168                 # Allow frames except in certain special cases
 169                 $wgOut->allowClickjacking();
 170
 171                 # If external diffs are enabled both globally and for the user,
 172                 # we'll use the application/x-external-editor interface to call
 173                 # an external diff tool like kompare, kdiff3, etc.
 174                 if ( $wgUseExternalEditor && $wgUser->getOption( 'externaldiff' ) ) {
 175                         global $wgServer, $wgScript, $wgLang;
 176                         $wgOut->disable();
 177                         header ( "Content-type: application/x-external-editor; charset=UTF-8" );
 178                         $url1 = $this->mTitle->getFullURL( array(
 179                                 'action' => 'raw',
 180                                 'oldid' => $this->mOldid
 181                         ) );
 182                         $url2 = $this->mTitle->getFullURL( array(
 183                                 'action' => 'raw',
 184                                 'oldid' => $this->mNewid
 185                         ) );
 186                         $special = $wgLang->getNsText( NS_SPECIAL );
 187                         $control = <<<CONTROL
 188                         [Process]
 189                         Type=Diff text
 190                         Engine=MediaWiki
 191                         Script={$wgServer}{$wgScript}
 192                         Special namespace={$special}
 193
 194                         [File]
 195                         Extension=wiki
 196                         URL=$url1
 197
 198                         [File 2]
 199                         Extension=wiki
 200                         URL=$url2
 201 CONTROL;
 202                         echo( $control );
 203
 204                         wfProfileOut( __METHOD__ );
 205                         return;
 206                 }
 207
 208                 $wgOut->setArticleFlag( false );
 209                 if ( !$this->loadRevisionData() ) {
 210                         // Sounds like a deleted revision... Let's see what we can do.
 211                         $deletedLink = $this->deletedLink( $this->mNewid );
 212
 213                         $t = $this->mTitle->getPrefixedText();
 214                         $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ),
 215                                         $this->deletedIdMarker( $this->mOldid ),
 216                                         $this->deletedIdMarker( $this->mNewid ) );
 217                         $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
 218                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", "<span class='plainlinks'>$d</span>" );
 219                         wfProfileOut( __METHOD__ );
 220                         return;
 221                 }
 222
 223                 wfRunHooks( 'DiffViewHeader', array( $this, $this->mOldRev, $this->mNewRev ) );
 224
 225                 if ( $this->mNewRev->isCurrent() ) {
 226                         $wgOut->setArticleFlag( true );
 227                 }
 228
 229                 # mOldid is false if the difference engine is called with a "vague" query for
 230                 # a diff between a version V and its previous version V' AND the version V
 231                 # is the first version of that article. In that case, V' does not exist.
 232                 if ( $this->mOldid === false ) {
 233                         $this->showFirstRevision();
 234                         $this->renderNewRevision();  // should we respect $diffOnly here or not?
 235                         wfProfileOut( __METHOD__ );
 236                         return;
 237                 }
 238
 239                 $oldTitle = $this->mOldPage->getPrefixedText();
 240                 $newTitle = $this->mNewPage->getPrefixedText();
 241                 if ( $oldTitle == $newTitle ) {
 242                         $wgOut->setPageTitle( $newTitle );
 243                 } else {
 244                         $wgOut->setPageTitle( $oldTitle . ', ' . $newTitle );
 245                 }
 246                 if ( $this->mNewPage->equals( $this->mOldPage ) ) {
 247                         $wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
 248                 } else {
 249                         $wgOut->setSubtitle( wfMsgExt( 'difference-multipage', array( 'parseinline' ) ) );
 250                 }
 251                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
 252
 253                 if ( !$this->mOldPage->userCanRead() || !$this->mNewPage->userCanRead() ) {
 254                         $wgOut->loginToUse();
 255                         $wgOut->output();
 256                         $wgOut->disable();
 257                         wfProfileOut( __METHOD__ );
 258                         return;
 259                 }
 260
 261                 $sk = $wgUser->getSkin();
 262                 if ( method_exists( $sk, 'suppressQuickbar' ) ) {
 263                         $sk->suppressQuickbar();
 264                 }
 265
 266                 // Check if page is editable
 267                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
 268                 if ( $editable && $this->mNewRev->isCurrent() && $wgUser->isAllowed( 'rollback' ) ) {
 269                         $wgOut->preventClickjacking();
 270                         $rollback = '&#160;&#160;&#160;' . $sk->generateRollback( $this->mNewRev );
 271                 } else {
 272                         $rollback = '';
 273                 }
 274
 275                 // Prepare a change patrol link, if applicable
 276                 if ( $wgUseRCPatrol && $this->mTitle->userCan( 'patrol' ) ) {
 277                         // If we've been given an explicit change identifier, use it; saves time
 278                         if ( $this->mRcidMarkPatrolled ) {
 279                                 $rcid = $this->mRcidMarkPatrolled;
 280                                 $rc = RecentChange::newFromId( $rcid );
 281                                 // Already patrolled?
 282                                 $rcid = is_object( $rc ) && !$rc->getAttribute( 'rc_patrolled' ) ? $rcid : 0;
 283                         } else {
 284                                 // Look for an unpatrolled change corresponding to this diff
 285                                 $db = wfGetDB( DB_SLAVE );
 286                                 $change = RecentChange::newFromConds(
 287                                         array(
 288                                         // Redundant user,timestamp condition so we can use the existing index
 289                                                 'rc_user_text'  => $this->mNewRev->getRawUserText(),
 290                                                 'rc_timestamp'  => $db->timestamp( $this->mNewRev->getTimestamp() ),
 291                                                 'rc_this_oldid' => $this->mNewid,
 292                                                 'rc_last_oldid' => $this->mOldid,
 293                                                 'rc_patrolled'  => 0
 294                                         ),
 295                                         __METHOD__
 296                                 );
 297                                 if ( $change instanceof RecentChange ) {
 298                                         $rcid = $change->mAttribs['rc_id'];
 299                                         $this->mRcidMarkPatrolled = $rcid;
 300                                 } else {
 301                                         // None found
 302                                         $rcid = 0;
 303                                 }
 304                         }
 305                         // Build the link
 306                         if ( $rcid ) {
 307                                 $wgOut->preventClickjacking();
 308                                 $token = $wgUser->editToken( $rcid );
 309                                 $patrol = ' <span class="patrollink">[' . $sk->link(
 310                                         $this->mTitle,
 311                                         wfMsgHtml( 'markaspatrolleddiff' ),
 312                                         array(),
 313                                         array(
 314                                                 'action' => 'markpatrolled',
 315                                                 'rcid' => $rcid,
 316                                                 'token' => $token,
 317                                         ),
 318                                         array(
 319                                                 'known',
 320                                                 'noclasses'
 321                                         )
 322                                 ) . ']</span>';
 323                         } else {
 324                                 $patrol = '';
 325                         }
 326                 } else {
 327                         $patrol = '';
 328                 }
 329
 330                 # Carry over 'diffonly' param via navigation links
 331                 if ( $diffOnly != $wgUser->getBoolOption( 'diffonly' ) ) {
 332                         $query['diffonly'] = $diffOnly;
 333                 }
 334
 335                 # Make "previous revision link"
 336                 $query['diff'] = 'prev';
 337                 $query['oldid'] = $this->mOldid;
 338                 # Cascade unhide param in links for easy deletion browsing
 339                 if ( $this->unhide ) {
 340                         $query['unhide'] = 1;
 341                 }
 342                 if ( !$this->mOldRev->getPrevious() ) {
 343                         $prevlink = '&#160;';
 344                 } else {
 345                         $prevlink = $sk->link(
 346                                 $this->mTitle,
 347                                 wfMsgHtml( 'previousdiff' ),
 348                                 array(
 349                                         'id' => 'differences-prevlink'
 350                                 ),
 351                                 $query,
 352                                 array(
 353                                         'known',
 354                                         'noclasses'
 355                                 )
 356                         );
 357                 }
 358
 359                 # Make "next revision link"
 360                 $query['diff'] = 'next';
 361                 $query['oldid'] = $this->mNewid;
 362                 # Skip next link on the top revision
 363                 if ( $this->mNewRev->isCurrent() ) {
 364                         $nextlink = '&#160;';
 365                 } else {
 366                         $nextlink = $sk->link(
 367                                 $this->mTitle,
 368                                 wfMsgHtml( 'nextdiff' ),
 369                                 array(
 370                                         'id' => 'differences-nextlink'
 371                                 ),
 372                                 $query,
 373                                 array(
 374                                         'known',
 375                                         'noclasses'
 376                                 )
 377                         );
 378                 }
 379
 380                 $oldminor = '';
 381                 $newminor = '';
 382
 383                 if ( $this->mOldRev->isMinor() ) {
 384                         $oldminor = ChangesList::flag( 'minor' );
 385                 }
 386                 if ( $this->mNewRev->isMinor() ) {
 387                         $newminor = ChangesList::flag( 'minor' );
 388                 }
 389
 390                 # Handle RevisionDelete links...
 391                 $ldel = $this->revisionDeleteLink( $this->mOldRev );
 392                 $rdel = $this->revisionDeleteLink( $this->mNewRev );
 393
 394                 $oldHeader = '<div id="mw-diff-otitle1"><strong>' . $this->mOldtitle . '</strong></div>' .
 395                         '<div id="mw-diff-otitle2">' .
 396                                 $sk->revUserTools( $this->mOldRev, !$this->unhide ) . '</div>' .
 397                         '<div id="mw-diff-otitle3">' . $oldminor .
 398                                 $sk->revComment( $this->mOldRev, !$diffOnly, !$this->unhide ) . $ldel . '</div>' .
 399                         '<div id="mw-diff-otitle4">' . $prevlink . '</div>';
 400                 $newHeader = '<div id="mw-diff-ntitle1"><strong>' . $this->mNewtitle . '</strong></div>' .
 401                         '<div id="mw-diff-ntitle2">' . $sk->revUserTools( $this->mNewRev, !$this->unhide ) .
 402                                 " $rollback</div>" .
 403                         '<div id="mw-diff-ntitle3">' . $newminor .
 404                                 $sk->revComment( $this->mNewRev, !$diffOnly, !$this->unhide ) . $rdel . '</div>' .
 405                         '<div id="mw-diff-ntitle4">' . $nextlink . $patrol . '</div>';
 406
 407                 # Check if this user can see the revisions
 408                 $allowed = $this->mOldRev->userCan( Revision::DELETED_TEXT )
 409                         && $this->mNewRev->userCan( Revision::DELETED_TEXT );
 410                 # Check if one of the revisions is deleted/suppressed
 411                 $deleted = $suppressed = false;
 412                 if ( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
 413                         $deleted = true; // old revisions text is hidden
 414                         if ( $this->mOldRev->isDeleted( Revision::DELETED_RESTRICTED ) )
 415                                 $suppressed = true; // also suppressed
 416                 }
 417                 if ( $this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
 418                         $deleted = true; // new revisions text is hidden
 419                         if ( $this->mNewRev->isDeleted( Revision::DELETED_RESTRICTED ) )
 420                                 $suppressed = true; // also suppressed
 421                 }
 422                 # If the diff cannot be shown due to a deleted revision, then output
 423                 # the diff header and links to unhide (if available)...
 424                 if ( $deleted && ( !$this->unhide || !$allowed ) ) {
 425                         $this->showDiffStyle();
 426                         $multi = $this->getMultiNotice();
 427                         $wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) );
 428                         if ( !$allowed ) {
 429                                 $msg = $suppressed ? 'rev-suppressed-no-diff' : 'rev-deleted-no-diff';
 430                                 # Give explanation for why revision is not visible
 431                                 $wgOut->wrapWikiMsg( "<div id='mw-$msg' class='mw-warning plainlinks'>\n$1\n</div>\n",
 432                                         array( $msg ) );
 433                         } else {
 434                                 # Give explanation and add a link to view the diff...
 435                                 $link = $this->mTitle->getFullUrl( array(
 436                                         'diff' => $this->mNewid,
 437                                         'oldid' => $this->mOldid,
 438                                         'unhide' => 1
 439                                 ) );
 440                                 $msg = $suppressed ? 'rev-suppressed-unhide-diff' : 'rev-deleted-unhide-diff';
 441                                 $wgOut->wrapWikiMsg( "<div id='mw-$msg' class='mw-warning plainlinks'>\n$1\n</div>\n", array( $msg, $link ) );
 442                         }
 443                 # Otherwise, output a regular diff...
 444                 } else {
 445                         # Add deletion notice if the user is viewing deleted content
 446                         $notice = '';
 447                         if ( $deleted ) {
 448                                 $msg = $suppressed ? 'rev-suppressed-diff-view' : 'rev-deleted-diff-view';
 449                                 $notice = "<div id='mw-$msg' class='mw-warning plainlinks'>\n" . wfMsgExt( $msg, 'parseinline' ) . "</div>\n";
 450                         }
 451                         $this->showDiff( $oldHeader, $newHeader, $notice );
 452                         if ( !$diffOnly ) {
 453                                 $this->renderNewRevision();
 454                         }
 455                 }
 456                 wfProfileOut( __METHOD__ );
 457         }
 458
 459         /**
 460          * @param $rev Revision
 461          * @return String
 462          */
 463         protected function revisionDeleteLink( $rev ) {
 464                 global $wgUser;
 465                 $link = '';
 466                 $canHide = $wgUser->isAllowed( 'deleterevision' );
 467                 // Show del/undel link if:
 468                 // (a) the user can delete revisions, or
 469                 // (b) the user can view deleted revision *and* this one is deleted
 470                 if ( $canHide || ( $rev->getVisibility() && $wgUser->isAllowed( 'deletedhistory' ) ) ) {
 471                         $sk = $wgUser->getSkin();
 472                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 473                                 $link = $sk->revDeleteLinkDisabled( $canHide ); // revision was hidden from sysops
 474                         } else {
 475                                 $query = array(
 476                                         'type'   => 'revision',
 477                                         'target' => $rev->mTitle->getPrefixedDbkey(),
 478                                         'ids'    => $rev->getId()
 479                                 );
 480                                 $link = $sk->revDeleteLink( $query,
 481                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ), $canHide );
 482                         }
 483                         $link = '&#160;&#160;&#160;' . $link . ' ';
 484                 }
 485                 return $link;
 486         }
 487
 488         /**
 489          * Show the new revision of the page.
 490          */
 491         function renderNewRevision() {
 492                 global $wgOut, $wgUser;
 493                 wfProfileIn( __METHOD__ );
 494                 # Add "current version as of X" title
 495                 $wgOut->addHTML( "<hr /><h2>{$this->mPagetitle}</h2>\n" );
 496                 # Page content may be handled by a hooked call instead...
 497                 if ( wfRunHooks( 'ArticleContentOnDiff', array( $this, $wgOut ) ) ) {
 498                         # Use the current version parser cache if applicable
 499                         $pCache = true;
 500                         if ( !$this->mNewRev->isCurrent() ) {
 501                                 $oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false );
 502                                 $pCache = false;
 503                         }
 504
 505                         $this->loadNewText();
 506                         $wgOut->setRevisionId( $this->mNewRev->getId() );
 507
 508                         if ( $this->mTitle->isCssJsSubpage() || $this->mTitle->isCssOrJsPage() ) {
 509                                 // Stolen from Article::view --AG 2007-10-11
 510                                 // Give hooks a chance to customise the output
 511                                 // @TODO: standardize this crap into one function
 512                                 if ( wfRunHooks( 'ShowRawCssJs', array( $this->mNewtext, $this->mTitle, $wgOut ) ) ) {
 513                                         // Wrap the whole lot in a <pre> and don't parse
 514                                         $m = array();
 515                                         preg_match( '!\.(css|js)$!u', $this->mTitle->getText(), $m );
 516                                         $wgOut->addHTML( "<pre class=\"mw-code mw-{$m[1]}\" dir=\"ltr\">\n" );
 517                                         $wgOut->addHTML( htmlspecialchars( $this->mNewtext ) );
 518                                         $wgOut->addHTML( "\n</pre>\n" );
 519                                 }
 520                         } elseif ( $pCache ) {
 521                                 $article = new Article( $this->mTitle, 0 );
 522                                 $pOutput = ParserCache::singleton()->get( $article, $wgOut->parserOptions() );
 523                                 if( $pOutput ) {
 524                                         $wgOut->addParserOutput( $pOutput );
 525                                 } else {
 526                                         $article->doViewParse();
 527                                 }
 528                         } else {
 529                                 $wgOut->addWikiTextTidy( $this->mNewtext );
 530                         }
 531
 532                         if ( !$this->mNewRev->isCurrent() ) {
 533                                 $wgOut->parserOptions()->setEditSection( $oldEditSectionSetting );
 534                         }
 535                 }
 536                 # Add redundant patrol link on bottom...
 537                 if ( $this->mRcidMarkPatrolled && $this->mTitle->quickUserCan( 'patrol' ) ) {
 538                         $sk = $wgUser->getSkin();
 539                         $token = $wgUser->editToken( $this->mRcidMarkPatrolled );
 540                         $wgOut->preventClickjacking();
 541                         $wgOut->addHTML(
 542                                 "<div class='patrollink'>[" . $sk->link(
 543                                         $this->mTitle,
 544                                         wfMsgHtml( 'markaspatrolleddiff' ),
 545                                         array(),
 546                                         array(
 547                                                 'action'        => 'markpatrolled',
 548                                                 'rcid'          => $this->mRcidMarkPatrolled,
 549                                                 'token'         => $token,
 550                                         )
 551                                 ) . ']</div>'
 552                          );
 553                 }
 554
 555                 wfProfileOut( __METHOD__ );
 556         }
 557
 558         /**
 559          * Show the first revision of an article. Uses normal diff headers in
 560          * contrast to normal "old revision" display style.
 561          */
 562         function showFirstRevision() {
 563                 global $wgOut, $wgUser;
 564                 wfProfileIn( __METHOD__ );
 565
 566                 # Get article text from the DB
 567                 #
 568                 if ( ! $this->loadNewText() ) {
 569                         $t = $this->mTitle->getPrefixedText();
 570                         $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ),
 571                                         $this->deletedIdMarker( $this->mOldid ),
 572                                         $this->deletedIdMarker( $this->mNewid ) );
 573                         $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
 574                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", "<span class='plainlinks'>$d</span>" );
 575                         wfProfileOut( __METHOD__ );
 576                         return;
 577                 }
 578                 if ( $this->mNewRev->isCurrent() ) {
 579                         $wgOut->setArticleFlag( true );
 580                 }
 581
 582                 # Check if user is allowed to look at this page. If not, bail out.
 583                 #
 584                 if ( !$this->mTitle->userCanRead() ) {
 585                         $wgOut->loginToUse();
 586                         $wgOut->output();
 587                         wfProfileOut( __METHOD__ );
 588                         throw new MWException( "Permission Error: you do not have access to view this page" );
 589                 }
 590
 591                 # Prepare the header box
 592                 #
 593                 $sk = $wgUser->getSkin();
 594
 595                 $next = $this->mTitle->getNextRevisionID( $this->mNewid );
 596                 if ( !$next ) {
 597                         $nextlink = '';
 598                 } else {
 599                         $nextlink = '<br />' . $sk->link(
 600                                 $this->mTitle,
 601                                 wfMsgHtml( 'nextdiff' ),
 602                                 array(
 603                                         'id' => 'differences-nextlink'
 604                                 ),
 605                                 array(
 606                                         'diff' => 'next',
 607                                         'oldid' => $this->mNewid,
 608                                 ),
 609                                 array(
 610                                         'known',
 611                                         'noclasses'
 612                                 )
 613                         );
 614                 }
 615                 $header = "<div class=\"firstrevisionheader\" style=\"text-align: center\">" .
 616                         $sk->revUserTools( $this->mNewRev ) . "<br />" . $sk->revComment( $this->mNewRev ) . $nextlink . "</div>\n";
 617
 618                 $wgOut->addHTML( $header );
 619
 620                 $wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
 621                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
 622
 623                 wfProfileOut( __METHOD__ );
 624         }
 625
 626         /**
 627          * Get the diff text, send it to $wgOut
 628          * Returns false if the diff could not be generated, otherwise returns true
 629          */
 630         function showDiff( $otitle, $ntitle, $notice = '' ) {
 631                 global $wgOut;
 632                 $diff = $this->getDiff( $otitle, $ntitle, $notice );
 633                 if ( $diff === false ) {
 634                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>(fixme, bug)</nowiki>", '' );
 635                         return false;
 636                 } else {
 637                         $this->showDiffStyle();
 638                         $wgOut->addHTML( $diff );
 639                         return true;
 640                 }
 641         }
 642
 643         /**
 644          * Add style sheets and supporting JS for diff display.
 645          */
 646         function showDiffStyle() {
 647                 global $wgOut;
 648                 $wgOut->addModuleStyles( 'mediawiki.legacy.diff' );
 649         }
 650
 651         /**
 652          * Get complete diff table, including header
 653          *
 654          * @param $otitle Title: old title
 655          * @param $ntitle Title: new title
 656          * @param $notice String: HTML between diff header and body
 657          * @return mixed
 658          */
 659         function getDiff( $otitle, $ntitle, $notice = '' ) {
 660                 $body = $this->getDiffBody();
 661                 if ( $body === false ) {
 662                         return false;
 663                 } else {
 664                         $multi = $this->getMultiNotice();
 665                         return $this->addHeader( $body, $otitle, $ntitle, $multi, $notice );
 666                 }
 667         }
 668
 669         /**
 670          * Get the diff table body, without header
 671          *
 672          * @return mixed (string/false)
 673          */
 674         public function getDiffBody() {
 675                 global $wgMemc;
 676                 wfProfileIn( __METHOD__ );
 677                 $this->mCacheHit = true;
 678                 // Check if the diff should be hidden from this user
 679                 if ( !$this->loadRevisionData() ) {
 680                         wfProfileOut( __METHOD__ );
 681                         return false;
 682                 } elseif ( $this->mOldRev && !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
 683                         wfProfileOut( __METHOD__ );
 684                         return false;
 685                 } elseif ( $this->mNewRev && !$this->mNewRev->userCan( Revision::DELETED_TEXT ) ) {
 686                         wfProfileOut( __METHOD__ );
 687                         return false;
 688                 }
 689                 // Short-circuit
 690                 if ( $this->mOldRev && $this->mNewRev
 691                         && $this->mOldRev->getID() == $this->mNewRev->getID() )
 692                 {
 693                         wfProfileOut( __METHOD__ );
 694                         return '';
 695                 }
 696                 // Cacheable?
 697                 $key = false;
 698                 if ( $this->mOldid && $this->mNewid ) {
 699                         $key = wfMemcKey( 'diff', 'version', MW_DIFF_VERSION,
 700                                 'oldid', $this->mOldid, 'newid', $this->mNewid );
 701                         // Try cache
 702                         if ( !$this->mRefreshCache ) {
 703                                 $difftext = $wgMemc->get( $key );
 704                                 if ( $difftext ) {
 705                                         wfIncrStats( 'diff_cache_hit' );
 706                                         $difftext = $this->localiseLineNumbers( $difftext );
 707                                         $difftext .= "\n<!-- diff cache key $key -->\n";
 708                                         wfProfileOut( __METHOD__ );
 709                                         return $difftext;
 710                                 }
 711                         } // don't try to load but save the result
 712                 }
 713                 $this->mCacheHit = false;
 714
 715                 // Loadtext is permission safe, this just clears out the diff
 716                 if ( !$this->loadText() ) {
 717                         wfProfileOut( __METHOD__ );
 718                         return false;
 719                 }
 720
 721                 $difftext = $this->generateDiffBody( $this->mOldtext, $this->mNewtext );
 722
 723                 // Save to cache for 7 days
 724                 if ( !wfRunHooks( 'AbortDiffCache', array( &$this ) ) ) {
 725                         wfIncrStats( 'diff_uncacheable' );
 726                 } elseif ( $key !== false && $difftext !== false ) {
 727                         wfIncrStats( 'diff_cache_miss' );
 728                         $wgMemc->set( $key, $difftext, 7 * 86400 );
 729                 } else {
 730                         wfIncrStats( 'diff_uncacheable' );
 731                 }
 732                 // Replace line numbers with the text in the user's language
 733                 if ( $difftext !== false ) {
 734                         $difftext = $this->localiseLineNumbers( $difftext );
 735                 }
 736                 wfProfileOut( __METHOD__ );
 737                 return $difftext;
 738         }
 739
 740         /**
 741          * Make sure the proper modules are loaded before we try to
 742          * make the diff
 743          */
 744         private function initDiffEngines() {
 745                 global $wgExternalDiffEngine;
 746                 if ( $wgExternalDiffEngine == 'wikidiff' && !function_exists( 'wikidiff_do_diff' ) ) {
 747                         wfProfileIn( __METHOD__ . '-php_wikidiff.so' );
 748                         wfDl( 'php_wikidiff' );
 749                         wfProfileOut( __METHOD__ . '-php_wikidiff.so' );
 750                 }
 751                 else if ( $wgExternalDiffEngine == 'wikidiff2' && !function_exists( 'wikidiff2_do_diff' ) ) {
 752                         wfProfileIn( __METHOD__ . '-php_wikidiff2.so' );
 753                         wfDl( 'wikidiff2' );
 754                         wfProfileOut( __METHOD__ . '-php_wikidiff2.so' );
 755                 }
 756         }
 757
 758         /**
 759          * Generate a diff, no caching
 760          *
 761          * @param $otext String: old text, must be already segmented
 762          * @param $ntext String: new text, must be already segmented
 763          */
 764         function generateDiffBody( $otext, $ntext ) {
 765                 global $wgExternalDiffEngine, $wgContLang;
 766
 767                 $otext = str_replace( "\r\n", "\n", $otext );
 768                 $ntext = str_replace( "\r\n", "\n", $ntext );
 769
 770                 $this->initDiffEngines();
 771
 772                 if ( $wgExternalDiffEngine == 'wikidiff' && function_exists( 'wikidiff_do_diff' ) ) {
 773                         # For historical reasons, external diff engine expects
 774                         # input text to be HTML-escaped already
 775                         $otext = htmlspecialchars ( $wgContLang->segmentForDiff( $otext ) );
 776                         $ntext = htmlspecialchars ( $wgContLang->segmentForDiff( $ntext ) );
 777                         return $wgContLang->unsegmentForDiff( wikidiff_do_diff( $otext, $ntext, 2 ) ) .
 778                         $this->debug( 'wikidiff1' );
 779                 }
 780
 781                 if ( $wgExternalDiffEngine == 'wikidiff2' && function_exists( 'wikidiff2_do_diff' ) ) {
 782                         # Better external diff engine, the 2 may some day be dropped
 783                         # This one does the escaping and segmenting itself
 784                         wfProfileIn( 'wikidiff2_do_diff' );
 785                         $text = wikidiff2_do_diff( $otext, $ntext, 2 );
 786                         $text .= $this->debug( 'wikidiff2' );
 787                         wfProfileOut( 'wikidiff2_do_diff' );
 788                         return $text;
 789                 }
 790                 if ( $wgExternalDiffEngine != 'wikidiff3' && $wgExternalDiffEngine !== false ) {
 791                         # Diff via the shell
 792                         global $wgTmpDirectory;
 793                         $tempName1 = tempnam( $wgTmpDirectory, 'diff_' );
 794                         $tempName2 = tempnam( $wgTmpDirectory, 'diff_' );
 795
 796                         $tempFile1 = fopen( $tempName1, "w" );
 797                         if ( !$tempFile1 ) {
 798                                 wfProfileOut( __METHOD__ );
 799                                 return false;
 800                         }
 801                         $tempFile2 = fopen( $tempName2, "w" );
 802                         if ( !$tempFile2 ) {
 803                                 wfProfileOut( __METHOD__ );
 804                                 return false;
 805                         }
 806                         fwrite( $tempFile1, $otext );
 807                         fwrite( $tempFile2, $ntext );
 808                         fclose( $tempFile1 );
 809                         fclose( $tempFile2 );
 810                         $cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
 811                         wfProfileIn( __METHOD__ . "-shellexec" );
 812                         $difftext = wfShellExec( $cmd );
 813                         $difftext .= $this->debug( "external $wgExternalDiffEngine" );
 814                         wfProfileOut( __METHOD__ . "-shellexec" );
 815                         unlink( $tempName1 );
 816                         unlink( $tempName2 );
 817                         wfProfileOut( __METHOD__ );
 818                         return $difftext;
 819                 }
 820
 821                 # Native PHP diff
 822                 $ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) );
 823                 $nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) );
 824                 $diffs = new Diff( $ota, $nta );
 825                 $formatter = new TableDiffFormatter();
 826                 $difftext = $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) ) .
 827                 wfProfileOut( __METHOD__ );
 828                 return $difftext;
 829         }
 830
 831         /**
 832          * Generate a debug comment indicating diff generating time,
 833          * server node, and generator backend.
 834          */
 835         protected function debug( $generator = "internal" ) {
 836                 global $wgShowHostnames;
 837                 if ( !$this->enableDebugComment ) {
 838                         return '';
 839                 }
 840                 $data = array( $generator );
 841                 if ( $wgShowHostnames ) {
 842                         $data[] = wfHostname();
 843                 }
 844                 $data[] = wfTimestamp( TS_DB );
 845                 return "<!-- diff generator: " .
 846                 implode( " ",
 847                 array_map(
 848                                         "htmlspecialchars",
 849                 $data ) ) .
 850                         " -->\n";
 851         }
 852
 853         /**
 854          * Replace line numbers with the text in the user's language
 855          */
 856         function localiseLineNumbers( $text ) {
 857                 return preg_replace_callback( '/<!--LINE (\d+)-->/',
 858                 array( &$this, 'localiseLineNumbersCb' ), $text );
 859         }
 860
 861         function localiseLineNumbersCb( $matches ) {
 862                 global $wgLang;
 863                 if ( $matches[1] === '1' && $this->mReducedLineNumbers ) return '';
 864                 return wfMsgExt( 'lineno', 'escape', $wgLang->formatNum( $matches[1] ) );
 865         }
 866
 867
 868         /**
 869          * If there are revisions between the ones being compared, return a note saying so.
 870          * @return string
 871          */
 872         function getMultiNotice() {
 873                 if ( !is_object( $this->mOldRev ) || !is_object( $this->mNewRev ) ) {
 874                         return '';
 875                 } elseif ( !$this->mOldPage->equals( $this->mNewPage ) ) {
 876                         // Comparing two different pages? Count would be meaningless.
 877                         return '';
 878                 }
 879
 880                 if ( $this->mOldRev->getTimestamp() > $this->mNewRev->getTimestamp() ) {
 881                         $oldRev = $this->mNewRev; // flip
 882                         $newRev = $this->mOldRev; // flip
 883                 } else { // normal case
 884                         $oldRev = $this->mOldRev;
 885                         $newRev = $this->mNewRev;
 886                 }
 887
 888                 $nEdits = $this->mTitle->countRevisionsBetween( $oldRev, $newRev );
 889                 if ( $nEdits > 0 ) {
 890                         $limit = 100; // use diff-multi-manyusers if too many users
 891                         $numUsers = $this->mTitle->countAuthorsBetween( $oldRev, $newRev, $limit );
 892                         return self::intermediateEditsMsg( $nEdits, $numUsers, $limit );
 893                 }
 894                 return ''; // nothing
 895         }
 896
 897         /**
 898          * Get a notice about how many intermediate edits and users there are
 899          * @param $numEdits int
 900          * @param $numUsers int
 901          * @param $limit int
 902          * @return string
 903          */
 904         public static function intermediateEditsMsg( $numEdits, $numUsers, $limit ) {
 905                 global $wgLang;
 906                 if ( $numUsers > $limit ) {
 907                         $msg = 'diff-multi-manyusers';
 908                         $numUsers = $limit;
 909                 } else {
 910                         $msg = 'diff-multi';
 911                 }
 912                 return wfMsgExt( $msg, 'parseinline',
 913                         $wgLang->formatnum( $numEdits ), $wgLang->formatnum( $numUsers ) );
 914         }
 915
 916         /**
 917          * Add the header to a diff body
 918          */
 919         static function addHeader( $diff, $otitle, $ntitle, $multi = '', $notice = '' ) {
 920                 $header = "<table class='diff'>";
 921                 if ( $diff ) { // Safari/Chrome show broken output if cols not used
 922                         $header .= "
 923                         <col class='diff-marker' />
 924                         <col class='diff-content' />
 925                         <col class='diff-marker' />
 926                         <col class='diff-content' />";
 927                         $colspan = 2;
 928                         $multiColspan = 4;
 929                 } else {
 930                         $colspan = 1;
 931                         $multiColspan = 2;
 932                 }
 933                 $header .= "
 934                 <tr valign='top'>
 935                 <td colspan='$colspan' class='diff-otitle'>{$otitle}</td>
 936                 <td colspan='$colspan' class='diff-ntitle'>{$ntitle}</td>
 937                 </tr>";
 938
 939                 if ( $multi != '' ) {
 940                         $header .= "<tr><td colspan='{$multiColspan}' align='center' class='diff-multi'>{$multi}</td></tr>";
 941                 }
 942                 if ( $notice != '' ) {
 943                         $header .= "<tr><td colspan='{$multiColspan}' align='center'>{$notice}</td></tr>";
 944                 }
 945
 946                 return $header . $diff . "</table>";
 947         }
 948
 949         /**
 950          * Use specified text instead of loading from the database
 951          */
 952         function setText( $oldText, $newText ) {
 953                 $this->mOldtext = $oldText;
 954                 $this->mNewtext = $newText;
 955                 $this->mTextLoaded = 2;
 956                 $this->mRevisionsLoaded = true;
 957         }
 958
 959         /**
 960          * Load revision metadata for the specified articles. If newid is 0, then compare
 961          * the old article in oldid to the current article; if oldid is 0, then
 962          * compare the current article to the immediately previous one (ignoring the
 963          * value of newid).
 964          *
 965          * If oldid is false, leave the corresponding revision object set
 966          * to false. This is impossible via ordinary user input, and is provided for
 967          * API convenience.
 968          */
 969         function loadRevisionData() {
 970                 global $wgLang, $wgUser;
 971                 if ( $this->mRevisionsLoaded ) {
 972                         return true;
 973                 } else {
 974                         // Whether it succeeds or fails, we don't want to try again
 975                         $this->mRevisionsLoaded = true;
 976                 }
 977
 978                 // Load the new revision object
 979                 $this->mNewRev = $this->mNewid
 980                         ? Revision::newFromId( $this->mNewid )
 981                         : Revision::newFromTitle( $this->mTitle );
 982                 if ( !$this->mNewRev instanceof Revision )
 983                         return false;
 984
 985                 // Update the new revision ID in case it was 0 (makes life easier doing UI stuff)
 986                 $this->mNewid = $this->mNewRev->getId();
 987
 988                 // Check if page is editable
 989                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
 990
 991                 // Set assorted variables
 992                 $timestamp = $wgLang->timeanddate( $this->mNewRev->getTimestamp(), true );
 993                 $dateofrev = $wgLang->date( $this->mNewRev->getTimestamp(), true );
 994                 $timeofrev = $wgLang->time( $this->mNewRev->getTimestamp(), true );
 995                 $this->mNewPage = $this->mNewRev->getTitle();
 996                 if ( $this->mNewRev->isCurrent() ) {
 997                         $newLink = $this->mNewPage->escapeLocalUrl( array(
 998                                 'oldid' => $this->mNewid
 999                         ) );
1000                         $this->mPagetitle = htmlspecialchars( wfMsg(
1001                                 'currentrev-asof',
1002                                 $timestamp,
1003                                 $dateofrev,
1004                                 $timeofrev
1005                         ) );
1006                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
1007                                 'action' => 'edit'
1008                         ) );
1009
1010                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
1011                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1012                 } else {
1013                         $newLink = $this->mNewPage->escapeLocalUrl( array(
1014                                 'oldid' => $this->mNewid
1015                         ) );
1016                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
1017                                 'action' => 'edit',
1018                                 'oldid' => $this->mNewid
1019                         ) );
1020                         $this->mPagetitle = htmlspecialchars( wfMsg(
1021                                 'revisionasof',
1022                                 $timestamp,
1023                                 $dateofrev,
1024                                 $timeofrev
1025                         ) );
1026
1027                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
1028                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1029                 }
1030                 if ( !$this->mNewRev->userCan( Revision::DELETED_TEXT ) ) {
1031                         $this->mNewtitle = "<span class='history-deleted'>{$this->mPagetitle}</span>";
1032                 } else if ( $this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
1033                         $this->mNewtitle = "<span class='history-deleted'>{$this->mNewtitle}</span>";
1034                 }
1035
1036                 // Load the old revision object
1037                 $this->mOldRev = false;
1038                 if ( $this->mOldid ) {
1039                         $this->mOldRev = Revision::newFromId( $this->mOldid );
1040                 } elseif ( $this->mOldid === 0 ) {
1041                         $rev = $this->mNewRev->getPrevious();
1042                         if ( $rev ) {
1043                                 $this->mOldid = $rev->getId();
1044                                 $this->mOldRev = $rev;
1045                         } else {
1046                                 // No previous revision; mark to show as first-version only.
1047                                 $this->mOldid = false;
1048                                 $this->mOldRev = false;
1049                         }
1050                 } /* elseif ( $this->mOldid === false ) leave mOldRev false; */
1051
1052                 if ( is_null( $this->mOldRev ) ) {
1053                         return false;
1054                 }
1055
1056                 if ( $this->mOldRev ) {
1057                         $this->mOldPage = $this->mOldRev->getTitle();
1058
1059                         $t = $wgLang->timeanddate( $this->mOldRev->getTimestamp(), true );
1060                         $dateofrev = $wgLang->date( $this->mOldRev->getTimestamp(), true );
1061                         $timeofrev = $wgLang->time( $this->mOldRev->getTimestamp(), true );
1062                         $oldLink = $this->mOldPage->escapeLocalUrl( array(
1063                                 'oldid' => $this->mOldid
1064                         ) );
1065                         $oldEdit = $this->mOldPage->escapeLocalUrl( array(
1066                                 'action' => 'edit',
1067                                 'oldid' => $this->mOldid
1068                         ) );
1069                         $this->mOldPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $t, $dateofrev, $timeofrev ) );
1070
1071                         $this->mOldtitle = "<a href='$oldLink'>{$this->mOldPagetitle}</a>"
1072                         . " (<a href='$oldEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1073                         // Add an "undo" link
1074                         if ( $editable && !$this->mOldRev->isDeleted( Revision::DELETED_TEXT ) && !$this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
1075                                 $undoLink = Html::element( 'a', array(
1076                                         'href' => $this->mNewPage->getLocalUrl( array(
1077                                                 'action' => 'edit',
1078                                                 'undoafter' => $this->mOldid,
1079                                                 'undo' => $this->mNewid ) ),
1080                                         'title' => $wgUser->getSkin()->titleAttrib( 'undo' )
1081                                 ), wfMsg( 'editundo' ) );
1082                                 $this->mNewtitle .= ' (' . $undoLink . ')';
1083                         }
1084
1085                         if ( !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
1086                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldPagetitle . '</span>';
1087                         } else if ( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
1088                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldtitle . '</span>';
1089                         }
1090                 }
1091
1092                 return true;
1093         }
1094
1095         /**
1096          * Load the text of the revisions, as well as revision data.
1097          */
1098         function loadText() {
1099                 if ( $this->mTextLoaded == 2 ) {
1100                         return true;
1101                 } else {
1102                         // Whether it succeeds or fails, we don't want to try again
1103                         $this->mTextLoaded = 2;
1104                 }
1105
1106                 if ( !$this->loadRevisionData() ) {
1107                         return false;
1108                 }
1109                 if ( $this->mOldRev ) {
1110                         $this->mOldtext = $this->mOldRev->getText( Revision::FOR_THIS_USER );
1111                         if ( $this->mOldtext === false ) {
1112                                 return false;
1113                         }
1114                 }
1115                 if ( $this->mNewRev ) {
1116                         $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1117                         if ( $this->mNewtext === false ) {
1118                                 return false;
1119                         }
1120                 }
1121                 return true;
1122         }
1123
1124         /**
1125          * Load the text of the new revision, not the old one
1126          */
1127         function loadNewText() {
1128                 if ( $this->mTextLoaded >= 1 ) {
1129                         return true;
1130                 } else {
1131                         $this->mTextLoaded = 1;
1132                 }
1133                 if ( !$this->loadRevisionData() ) {
1134                         return false;
1135                 }
1136                 $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1137                 return true;
1138         }
1139 }