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          * @param $rcid Integer ??? FIXME (default 0)
  63          * @param $refreshCache boolean If set, refreshes the diff cache
  64          * @param $unhide boolean If set, allow viewing deleted revs
  65          */
  66         function __construct( $titleObj = null, $old = 0, $new = 0, $rcid = 0,
  67                 $refreshCache = false, $unhide = false )
  68         {
  69                 if ( $titleObj ) {
  70                         $this->mTitle = $titleObj;
  71                 } else {
  72                         global $wgTitle;
  73                         $this->mTitle = $wgTitle; // @TODO: get rid of this
  74                 }
  75                 wfDebug( "DifferenceEngine old '$old' new '$new' rcid '$rcid'\n" );
  76
  77                 if ( 'prev' === $new ) {
  78                         # Show diff between revision $old and the previous one.
  79                         # Get previous one from DB.
  80                         $this->mNewid = intval( $old );
  81                         $this->mOldid = $this->mTitle->getPreviousRevisionID( $this->mNewid );
  82                 } elseif ( 'next' === $new ) {
  83                         # Show diff between revision $old and the next one.
  84                         # Get next one from DB.
  85                         $this->mOldid = intval( $old );
  86                         $this->mNewid = $this->mTitle->getNextRevisionID( $this->mOldid );
  87                         if ( false === $this->mNewid ) {
  88                                 # if no result, NewId points to the newest old revision. The only newer
  89                                 # revision is cur, which is "0".
  90                                 $this->mNewid = 0;
  91                         }
  92                 } else {
  93                         $this->mOldid = intval( $old );
  94                         $this->mNewid = intval( $new );
  95                         wfRunHooks( 'NewDifferenceEngine', array( &$titleObj, &$this->mOldid, &$this->mNewid, $old, $new ) );
  96                 }
  97                 $this->mRcidMarkPatrolled = intval( $rcid );  # force it to be an integer
  98                 $this->mRefreshCache = $refreshCache;
  99                 $this->unhide = $unhide;
 100         }
 101
 102         /**
 103          * @param $value bool
 104          */
 105         function setReducedLineNumbers( $value = true ) {
 106                 $this->mReducedLineNumbers = $value;
 107         }
 108
 109         /**
 110          * @return Title
 111          */
 112         function getTitle() {
 113                 return $this->mTitle;
 114         }
 115
 116         /**
 117          * @return bool
 118          */
 119         function wasCacheHit() {
 120                 return $this->mCacheHit;
 121         }
 122
 123         /**
 124          * @return int
 125          */
 126         function getOldid() {
 127                 return $this->mOldid;
 128         }
 129
 130         /**
 131          * @return Bool|int
 132          */
 133         function getNewid() {
 134                 return $this->mNewid;
 135         }
 136
 137         /**
 138          * Look up a special:Undelete link to the given deleted revision id,
 139          * as a workaround for being unable to load deleted diffs in currently.
 140          *
 141          * @param int $id revision ID
 142          * @return mixed URL or false
 143          */
 144         function deletedLink( $id ) {
 145                 global $wgUser;
 146                 if ( $wgUser->isAllowed( 'deletedhistory' ) ) {
 147                         $dbr = wfGetDB( DB_SLAVE );
 148                         $row = $dbr->selectRow('archive', '*',
 149                                 array( 'ar_rev_id' => $id ),
 150                                 __METHOD__ );
 151                         if ( $row ) {
 152                                 $rev = Revision::newFromArchiveRow( $row );
 153                                 $title = Title::makeTitleSafe( $row->ar_namespace, $row->ar_title );
 154                                 return SpecialPage::getTitleFor( 'Undelete' )->getFullURL( array(
 155                                         'target' => $title->getPrefixedText(),
 156                                         'timestamp' => $rev->getTimestamp()
 157                                 ));
 158                         }
 159                 }
 160                 return false;
 161         }
 162
 163         /**
 164          * Build a wikitext link toward a deleted revision, if viewable.
 165          *
 166          * @param int $id revision ID
 167          * @return string wikitext fragment
 168          */
 169         function deletedIdMarker( $id ) {
 170                 $link = $this->deletedLink( $id );
 171                 if ( $link ) {
 172                         return "[$link $id]";
 173                 } else {
 174                         return $id;
 175                 }
 176         }
 177
 178         function showDiffPage( $diffOnly = false ) {
 179                 global $wgUser, $wgOut, $wgUseExternalEditor, $wgUseRCPatrol;
 180                 wfProfileIn( __METHOD__ );
 181
 182                 # Allow frames except in certain special cases
 183                 $wgOut->allowClickjacking();
 184
 185                 # If external diffs are enabled both globally and for the user,
 186                 # we'll use the application/x-external-editor interface to call
 187                 # an external diff tool like kompare, kdiff3, etc.
 188                 if ( $wgUseExternalEditor && $wgUser->getOption( 'externaldiff' ) ) {
 189                         global $wgServer, $wgScript, $wgLang;
 190                         $wgOut->disable();
 191                         header ( "Content-type: application/x-external-editor; charset=UTF-8" );
 192                         $url1 = $this->mTitle->getFullURL( array(
 193                                 'action' => 'raw',
 194                                 'oldid' => $this->mOldid
 195                         ) );
 196                         $url2 = $this->mTitle->getFullURL( array(
 197                                 'action' => 'raw',
 198                                 'oldid' => $this->mNewid
 199                         ) );
 200                         $special = $wgLang->getNsText( NS_SPECIAL );
 201                         $control = <<<CONTROL
 202                         [Process]
 203                         Type=Diff text
 204                         Engine=MediaWiki
 205                         Script={$wgServer}{$wgScript}
 206                         Special namespace={$special}
 207
 208                         [File]
 209                         Extension=wiki
 210                         URL=$url1
 211
 212                         [File 2]
 213                         Extension=wiki
 214                         URL=$url2
 215 CONTROL;
 216                         echo( $control );
 217
 218                         wfProfileOut( __METHOD__ );
 219                         return;
 220                 }
 221
 222                 $wgOut->setArticleFlag( false );
 223                 if ( !$this->loadRevisionData() ) {
 224                         // Sounds like a deleted revision... Let's see what we can do.
 225                         $t = $this->mTitle->getPrefixedText();
 226                         $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ),
 227                                 $this->deletedIdMarker( $this->mOldid ),
 228                                 $this->deletedIdMarker( $this->mNewid ) );
 229                         $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
 230                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", "<span class='plainlinks'>$d</span>" );
 231                         wfProfileOut( __METHOD__ );
 232                         return;
 233                 }
 234
 235                 wfRunHooks( 'DiffViewHeader', array( $this, $this->mOldRev, $this->mNewRev ) );
 236
 237                 if ( $this->mNewRev->isCurrent() ) {
 238                         $wgOut->setArticleFlag( true );
 239                 }
 240
 241                 # mOldid is false if the difference engine is called with a "vague" query for
 242                 # a diff between a version V and its previous version V' AND the version V
 243                 # is the first version of that article. In that case, V' does not exist.
 244                 if ( $this->mOldid === false ) {
 245                         $this->showFirstRevision();
 246                         $this->renderNewRevision();  // should we respect $diffOnly here or not?
 247                         wfProfileOut( __METHOD__ );
 248                         return;
 249                 }
 250
 251                 $oldTitle = $this->mOldPage->getPrefixedText();
 252                 $newTitle = $this->mNewPage->getPrefixedText();
 253                 if ( $oldTitle == $newTitle ) {
 254                         $wgOut->setPageTitle( $newTitle );
 255                 } else {
 256                         $wgOut->setPageTitle( $oldTitle . ', ' . $newTitle );
 257                 }
 258                 if ( $this->mNewPage->equals( $this->mOldPage ) ) {
 259                         $wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
 260                 } else {
 261                         $wgOut->setSubtitle( wfMsgExt( 'difference-multipage', array( 'parseinline' ) ) );
 262                 }
 263                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
 264
 265                 if ( !$this->mOldPage->userCanRead() || !$this->mNewPage->userCanRead() ) {
 266                         $wgOut->loginToUse();
 267                         $wgOut->output();
 268                         $wgOut->disable();
 269                         wfProfileOut( __METHOD__ );
 270                         return;
 271                 }
 272
 273                 $sk = $wgUser->getSkin();
 274                 if ( method_exists( $sk, 'suppressQuickbar' ) ) {
 275                         $sk->suppressQuickbar();
 276                 }
 277
 278                 // Check if page is editable
 279                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
 280                 if ( $editable && $this->mNewRev->isCurrent() && $wgUser->isAllowed( 'rollback' ) ) {
 281                         $wgOut->preventClickjacking();
 282                         $rollback = '&#160;&#160;&#160;' . $sk->generateRollback( $this->mNewRev );
 283                 } else {
 284                         $rollback = '';
 285                 }
 286
 287                 // Prepare a change patrol link, if applicable
 288                 if ( $wgUseRCPatrol && $this->mTitle->userCan( 'patrol' ) ) {
 289                         // If we've been given an explicit change identifier, use it; saves time
 290                         if ( $this->mRcidMarkPatrolled ) {
 291                                 $rcid = $this->mRcidMarkPatrolled;
 292                                 $rc = RecentChange::newFromId( $rcid );
 293                                 // Already patrolled?
 294                                 $rcid = is_object( $rc ) && !$rc->getAttribute( 'rc_patrolled' ) ? $rcid : 0;
 295                         } else {
 296                                 // Look for an unpatrolled change corresponding to this diff
 297                                 $db = wfGetDB( DB_SLAVE );
 298                                 $change = RecentChange::newFromConds(
 299                                         array(
 300                                         // Redundant user,timestamp condition so we can use the existing index
 301                                                 'rc_user_text'  => $this->mNewRev->getRawUserText(),
 302                                                 'rc_timestamp'  => $db->timestamp( $this->mNewRev->getTimestamp() ),
 303                                                 'rc_this_oldid' => $this->mNewid,
 304                                                 'rc_last_oldid' => $this->mOldid,
 305                                                 'rc_patrolled'  => 0
 306                                         ),
 307                                         __METHOD__
 308                                 );
 309                                 if ( $change instanceof RecentChange ) {
 310                                         $rcid = $change->mAttribs['rc_id'];
 311                                         $this->mRcidMarkPatrolled = $rcid;
 312                                 } else {
 313                                         // None found
 314                                         $rcid = 0;
 315                                 }
 316                         }
 317                         // Build the link
 318                         if ( $rcid ) {
 319                                 $wgOut->preventClickjacking();
 320                                 $token = $wgUser->editToken( $rcid );
 321                                 $patrol = ' <span class="patrollink">[' . $sk->link(
 322                                         $this->mTitle,
 323                                         wfMsgHtml( 'markaspatrolleddiff' ),
 324                                         array(),
 325                                         array(
 326                                                 'action' => 'markpatrolled',
 327                                                 'rcid' => $rcid,
 328                                                 'token' => $token,
 329                                         ),
 330                                         array(
 331                                                 'known',
 332                                                 'noclasses'
 333                                         )
 334                                 ) . ']</span>';
 335                         } else {
 336                                 $patrol = '';
 337                         }
 338                 } else {
 339                         $patrol = '';
 340                 }
 341
 342                 # Carry over 'diffonly' param via navigation links
 343                 if ( $diffOnly != $wgUser->getBoolOption( 'diffonly' ) ) {
 344                         $query['diffonly'] = $diffOnly;
 345                 }
 346
 347                 # Make "previous revision link"
 348                 $query['diff'] = 'prev';
 349                 $query['oldid'] = $this->mOldid;
 350                 # Cascade unhide param in links for easy deletion browsing
 351                 if ( $this->unhide ) {
 352                         $query['unhide'] = 1;
 353                 }
 354                 if ( !$this->mOldRev->getPrevious() ) {
 355                         $prevlink = '&#160;';
 356                 } else {
 357                         $prevlink = $sk->link(
 358                                 $this->mTitle,
 359                                 wfMsgHtml( 'previousdiff' ),
 360                                 array(
 361                                         'id' => 'differences-prevlink'
 362                                 ),
 363                                 $query,
 364                                 array(
 365                                         'known',
 366                                         'noclasses'
 367                                 )
 368                         );
 369                 }
 370
 371                 # Make "next revision link"
 372                 $query['diff'] = 'next';
 373                 $query['oldid'] = $this->mNewid;
 374                 # Skip next link on the top revision
 375                 if ( $this->mNewRev->isCurrent() ) {
 376                         $nextlink = '&#160;';
 377                 } else {
 378                         $nextlink = $sk->link(
 379                                 $this->mTitle,
 380                                 wfMsgHtml( 'nextdiff' ),
 381                                 array(
 382                                         'id' => 'differences-nextlink'
 383                                 ),
 384                                 $query,
 385                                 array(
 386                                         'known',
 387                                         'noclasses'
 388                                 )
 389                         );
 390                 }
 391
 392                 $oldminor = '';
 393                 $newminor = '';
 394
 395                 if ( $this->mOldRev->isMinor() ) {
 396                         $oldminor = ChangesList::flag( 'minor' );
 397                 }
 398                 if ( $this->mNewRev->isMinor() ) {
 399                         $newminor = ChangesList::flag( 'minor' );
 400                 }
 401
 402                 # Handle RevisionDelete links...
 403                 $ldel = $this->revisionDeleteLink( $this->mOldRev );
 404                 $rdel = $this->revisionDeleteLink( $this->mNewRev );
 405
 406                 $oldHeader = '<div id="mw-diff-otitle1"><strong>' . $this->mOldtitle . '</strong></div>' .
 407                         '<div id="mw-diff-otitle2">' .
 408                                 $sk->revUserTools( $this->mOldRev, !$this->unhide ) . '</div>' .
 409                         '<div id="mw-diff-otitle3">' . $oldminor .
 410                                 $sk->revComment( $this->mOldRev, !$diffOnly, !$this->unhide ) . $ldel . '</div>' .
 411                         '<div id="mw-diff-otitle4">' . $prevlink . '</div>';
 412                 $newHeader = '<div id="mw-diff-ntitle1"><strong>' . $this->mNewtitle . '</strong></div>' .
 413                         '<div id="mw-diff-ntitle2">' . $sk->revUserTools( $this->mNewRev, !$this->unhide ) .
 414                                 " $rollback</div>" .
 415                         '<div id="mw-diff-ntitle3">' . $newminor .
 416                                 $sk->revComment( $this->mNewRev, !$diffOnly, !$this->unhide ) . $rdel . '</div>' .
 417                         '<div id="mw-diff-ntitle4">' . $nextlink . $patrol . '</div>';
 418
 419                 # Check if this user can see the revisions
 420                 $allowed = $this->mOldRev->userCan( Revision::DELETED_TEXT )
 421                         && $this->mNewRev->userCan( Revision::DELETED_TEXT );
 422                 # Check if one of the revisions is deleted/suppressed
 423                 $deleted = $suppressed = false;
 424                 if ( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
 425                         $deleted = true; // old revisions text is hidden
 426                         if ( $this->mOldRev->isDeleted( Revision::DELETED_RESTRICTED ) )
 427                                 $suppressed = true; // also suppressed
 428                 }
 429                 if ( $this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
 430                         $deleted = true; // new revisions text is hidden
 431                         if ( $this->mNewRev->isDeleted( Revision::DELETED_RESTRICTED ) )
 432                                 $suppressed = true; // also suppressed
 433                 }
 434                 # If the diff cannot be shown due to a deleted revision, then output
 435                 # the diff header and links to unhide (if available)...
 436                 if ( $deleted && ( !$this->unhide || !$allowed ) ) {
 437                         $this->showDiffStyle();
 438                         $multi = $this->getMultiNotice();
 439                         $wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) );
 440                         if ( !$allowed ) {
 441                                 $msg = $suppressed ? 'rev-suppressed-no-diff' : 'rev-deleted-no-diff';
 442                                 # Give explanation for why revision is not visible
 443                                 $wgOut->wrapWikiMsg( "<div id='mw-$msg' class='mw-warning plainlinks'>\n$1\n</div>\n",
 444                                         array( $msg ) );
 445                         } else {
 446                                 # Give explanation and add a link to view the diff...
 447                                 $link = $this->mTitle->getFullUrl( array(
 448                                         'diff' => $this->mNewid,
 449                                         'oldid' => $this->mOldid,
 450                                         'unhide' => 1
 451                                 ) );
 452                                 $msg = $suppressed ? 'rev-suppressed-unhide-diff' : 'rev-deleted-unhide-diff';
 453                                 $wgOut->wrapWikiMsg( "<div id='mw-$msg' class='mw-warning plainlinks'>\n$1\n</div>\n", array( $msg, $link ) );
 454                         }
 455                 # Otherwise, output a regular diff...
 456                 } else {
 457                         # Add deletion notice if the user is viewing deleted content
 458                         $notice = '';
 459                         if ( $deleted ) {
 460                                 $msg = $suppressed ? 'rev-suppressed-diff-view' : 'rev-deleted-diff-view';
 461                                 $notice = "<div id='mw-$msg' class='mw-warning plainlinks'>\n" . wfMsgExt( $msg, 'parseinline' ) . "</div>\n";
 462                         }
 463                         $this->showDiff( $oldHeader, $newHeader, $notice );
 464                         if ( !$diffOnly ) {
 465                                 $this->renderNewRevision();
 466                         }
 467                 }
 468                 wfProfileOut( __METHOD__ );
 469         }
 470
 471         /**
 472          * @param $rev Revision
 473          * @return String
 474          */
 475         protected function revisionDeleteLink( $rev ) {
 476                 global $wgUser;
 477                 $link = '';
 478                 $canHide = $wgUser->isAllowed( 'deleterevision' );
 479                 // Show del/undel link if:
 480                 // (a) the user can delete revisions, or
 481                 // (b) the user can view deleted revision *and* this one is deleted
 482                 if ( $canHide || ( $rev->getVisibility() && $wgUser->isAllowed( 'deletedhistory' ) ) ) {
 483                         $sk = $wgUser->getSkin();
 484                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 485                                 $link = $sk->revDeleteLinkDisabled( $canHide ); // revision was hidden from sysops
 486                         } else {
 487                                 $query = array(
 488                                         'type'   => 'revision',
 489                                         'target' => $rev->mTitle->getPrefixedDbkey(),
 490                                         'ids'    => $rev->getId()
 491                                 );
 492                                 $link = $sk->revDeleteLink( $query,
 493                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ), $canHide );
 494                         }
 495                         $link = '&#160;&#160;&#160;' . $link . ' ';
 496                 }
 497                 return $link;
 498         }
 499
 500         /**
 501          * Show the new revision of the page.
 502          */
 503         function renderNewRevision() {
 504                 global $wgOut, $wgUser;
 505                 wfProfileIn( __METHOD__ );
 506                 # Add "current version as of X" title
 507                 $wgOut->addHTML( "<hr class='diff-hr' />
 508                 <h2 class='diff-currentversion-title'>{$this->mPagetitle}</h2>\n" );
 509                 # Page content may be handled by a hooked call instead...
 510                 if ( wfRunHooks( 'ArticleContentOnDiff', array( $this, $wgOut ) ) ) {
 511                         # Use the current version parser cache if applicable
 512                         $pCache = true;
 513                         if ( !$this->mNewRev->isCurrent() ) {
 514                                 $oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false );
 515                                 $pCache = false;
 516                         }
 517
 518                         $this->loadNewText();
 519                         $wgOut->setRevisionId( $this->mNewRev->getId() );
 520
 521                         if ( $this->mTitle->isCssJsSubpage() || $this->mTitle->isCssOrJsPage() ) {
 522                                 // Stolen from Article::view --AG 2007-10-11
 523                                 // Give hooks a chance to customise the output
 524                                 // @TODO: standardize this crap into one function
 525                                 if ( wfRunHooks( 'ShowRawCssJs', array( $this->mNewtext, $this->mTitle, $wgOut ) ) ) {
 526                                         // Wrap the whole lot in a <pre> and don't parse
 527                                         $m = array();
 528                                         preg_match( '!\.(css|js)$!u', $this->mTitle->getText(), $m );
 529                                         $wgOut->addHTML( "<pre class=\"mw-code mw-{$m[1]}\" dir=\"ltr\">\n" );
 530                                         $wgOut->addHTML( htmlspecialchars( $this->mNewtext ) );
 531                                         $wgOut->addHTML( "\n</pre>\n" );
 532                                 }
 533                         } elseif ( $pCache ) {
 534                                 $article = new Article( $this->mTitle, 0 );
 535                                 $pOutput = ParserCache::singleton()->get( $article, $wgOut->parserOptions() );
 536                                 if( $pOutput ) {
 537                                         $wgOut->addParserOutput( $pOutput );
 538                                 } else {
 539                                         $article->doViewParse();
 540                                 }
 541                         } else {
 542                                 $wgOut->addWikiTextTidy( $this->mNewtext );
 543                         }
 544
 545                         if ( !$this->mNewRev->isCurrent() ) {
 546                                 $wgOut->parserOptions()->setEditSection( $oldEditSectionSetting );
 547                         }
 548                 }
 549                 # Add redundant patrol link on bottom...
 550                 if ( $this->mRcidMarkPatrolled && $this->mTitle->quickUserCan( 'patrol' ) ) {
 551                         $sk = $wgUser->getSkin();
 552                         $token = $wgUser->editToken( $this->mRcidMarkPatrolled );
 553                         $wgOut->preventClickjacking();
 554                         $wgOut->addHTML(
 555                                 "<div class='patrollink'>[" . $sk->link(
 556                                         $this->mTitle,
 557                                         wfMsgHtml( 'markaspatrolleddiff' ),
 558                                         array(),
 559                                         array(
 560                                                 'action'        => 'markpatrolled',
 561                                                 'rcid'          => $this->mRcidMarkPatrolled,
 562                                                 'token'         => $token,
 563                                         )
 564                                 ) . ']</div>'
 565                          );
 566                 }
 567
 568                 wfProfileOut( __METHOD__ );
 569         }
 570
 571         /**
 572          * Show the first revision of an article. Uses normal diff headers in
 573          * contrast to normal "old revision" display style.
 574          */
 575         function showFirstRevision() {
 576                 global $wgOut, $wgUser;
 577                 wfProfileIn( __METHOD__ );
 578
 579                 # Get article text from the DB
 580                 #
 581                 if ( ! $this->loadNewText() ) {
 582                         $t = $this->mTitle->getPrefixedText();
 583                         $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ),
 584                                         $this->deletedIdMarker( $this->mOldid ),
 585                                         $this->deletedIdMarker( $this->mNewid ) );
 586                         $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
 587                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", "<span class='plainlinks'>$d</span>" );
 588                         wfProfileOut( __METHOD__ );
 589                         return;
 590                 }
 591                 if ( $this->mNewRev->isCurrent() ) {
 592                         $wgOut->setArticleFlag( true );
 593                 }
 594
 595                 # Check if user is allowed to look at this page. If not, bail out.
 596                 #
 597                 if ( !$this->mTitle->userCanRead() ) {
 598                         $wgOut->loginToUse();
 599                         $wgOut->output();
 600                         wfProfileOut( __METHOD__ );
 601                         throw new MWException( "Permission Error: you do not have access to view this page" );
 602                 }
 603
 604                 # Prepare the header box
 605                 #
 606                 $sk = $wgUser->getSkin();
 607
 608                 $next = $this->mTitle->getNextRevisionID( $this->mNewid );
 609                 if ( !$next ) {
 610                         $nextlink = '';
 611                 } else {
 612                         $nextlink = '<br />' . $sk->link(
 613                                 $this->mTitle,
 614                                 wfMsgHtml( 'nextdiff' ),
 615                                 array(
 616                                         'id' => 'differences-nextlink'
 617                                 ),
 618                                 array(
 619                                         'diff' => 'next',
 620                                         'oldid' => $this->mNewid,
 621                                 ),
 622                                 array(
 623                                         'known',
 624                                         'noclasses'
 625                                 )
 626                         );
 627                 }
 628                 $header = "<div class=\"firstrevisionheader\" style=\"text-align: center\">" .
 629                         $sk->revUserTools( $this->mNewRev ) . "<br />" . $sk->revComment( $this->mNewRev ) . $nextlink . "</div>\n";
 630
 631                 $wgOut->addHTML( $header );
 632
 633                 $wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
 634                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
 635
 636                 wfProfileOut( __METHOD__ );
 637         }
 638
 639         /**
 640          * Get the diff text, send it to $wgOut
 641          * Returns false if the diff could not be generated, otherwise returns true
 642          *
 643          * @return bool
 644          */
 645         function showDiff( $otitle, $ntitle, $notice = '' ) {
 646                 global $wgOut;
 647                 $diff = $this->getDiff( $otitle, $ntitle, $notice );
 648                 if ( $diff === false ) {
 649                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>(fixme, bug)</nowiki>", '' );
 650                         return false;
 651                 } else {
 652                         $this->showDiffStyle();
 653                         $wgOut->addHTML( $diff );
 654                         return true;
 655                 }
 656         }
 657
 658         /**
 659          * Add style sheets and supporting JS for diff display.
 660          */
 661         function showDiffStyle() {
 662                 global $wgOut;
 663                 $wgOut->addModuleStyles( 'mediawiki.action.history.diff' );
 664         }
 665
 666         /**
 667          * Get complete diff table, including header
 668          *
 669          * @param $otitle Title: old title
 670          * @param $ntitle Title: new title
 671          * @param $notice String: HTML between diff header and body
 672          * @return mixed
 673          */
 674         function getDiff( $otitle, $ntitle, $notice = '' ) {
 675                 $body = $this->getDiffBody();
 676                 if ( $body === false ) {
 677                         return false;
 678                 } else {
 679                         $multi = $this->getMultiNotice();
 680                         return $this->addHeader( $body, $otitle, $ntitle, $multi, $notice );
 681                 }
 682         }
 683
 684         /**
 685          * Get the diff table body, without header
 686          *
 687          * @return mixed (string/false)
 688          */
 689         public function getDiffBody() {
 690                 global $wgMemc;
 691                 wfProfileIn( __METHOD__ );
 692                 $this->mCacheHit = true;
 693                 // Check if the diff should be hidden from this user
 694                 if ( !$this->loadRevisionData() ) {
 695                         wfProfileOut( __METHOD__ );
 696                         return false;
 697                 } elseif ( $this->mOldRev && !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
 698                         wfProfileOut( __METHOD__ );
 699                         return false;
 700                 } elseif ( $this->mNewRev && !$this->mNewRev->userCan( Revision::DELETED_TEXT ) ) {
 701                         wfProfileOut( __METHOD__ );
 702                         return false;
 703                 }
 704                 // Short-circuit
 705                 if ( $this->mOldRev && $this->mNewRev
 706                         && $this->mOldRev->getID() == $this->mNewRev->getID() )
 707                 {
 708                         wfProfileOut( __METHOD__ );
 709                         return '';
 710                 }
 711                 // Cacheable?
 712                 $key = false;
 713                 if ( $this->mOldid && $this->mNewid ) {
 714                         $key = wfMemcKey( 'diff', 'version', MW_DIFF_VERSION,
 715                                 'oldid', $this->mOldid, 'newid', $this->mNewid );
 716                         // Try cache
 717                         if ( !$this->mRefreshCache ) {
 718                                 $difftext = $wgMemc->get( $key );
 719                                 if ( $difftext ) {
 720                                         wfIncrStats( 'diff_cache_hit' );
 721                                         $difftext = $this->localiseLineNumbers( $difftext );
 722                                         $difftext .= "\n<!-- diff cache key $key -->\n";
 723                                         wfProfileOut( __METHOD__ );
 724                                         return $difftext;
 725                                 }
 726                         } // don't try to load but save the result
 727                 }
 728                 $this->mCacheHit = false;
 729
 730                 // Loadtext is permission safe, this just clears out the diff
 731                 if ( !$this->loadText() ) {
 732                         wfProfileOut( __METHOD__ );
 733                         return false;
 734                 }
 735
 736                 $difftext = $this->generateDiffBody( $this->mOldtext, $this->mNewtext );
 737
 738                 // Save to cache for 7 days
 739                 if ( !wfRunHooks( 'AbortDiffCache', array( &$this ) ) ) {
 740                         wfIncrStats( 'diff_uncacheable' );
 741                 } elseif ( $key !== false && $difftext !== false ) {
 742                         wfIncrStats( 'diff_cache_miss' );
 743                         $wgMemc->set( $key, $difftext, 7 * 86400 );
 744                 } else {
 745                         wfIncrStats( 'diff_uncacheable' );
 746                 }
 747                 // Replace line numbers with the text in the user's language
 748                 if ( $difftext !== false ) {
 749                         $difftext = $this->localiseLineNumbers( $difftext );
 750                 }
 751                 wfProfileOut( __METHOD__ );
 752                 return $difftext;
 753         }
 754
 755         /**
 756          * Make sure the proper modules are loaded before we try to
 757          * make the diff
 758          */
 759         private function initDiffEngines() {
 760                 global $wgExternalDiffEngine;
 761                 if ( $wgExternalDiffEngine == 'wikidiff' && !function_exists( 'wikidiff_do_diff' ) ) {
 762                         wfProfileIn( __METHOD__ . '-php_wikidiff.so' );
 763                         wfDl( 'php_wikidiff' );
 764                         wfProfileOut( __METHOD__ . '-php_wikidiff.so' );
 765                 }
 766                 elseif ( $wgExternalDiffEngine == 'wikidiff2' && !function_exists( 'wikidiff2_do_diff' ) ) {
 767                         wfProfileIn( __METHOD__ . '-php_wikidiff2.so' );
 768                         wfDl( 'wikidiff2' );
 769                         wfProfileOut( __METHOD__ . '-php_wikidiff2.so' );
 770                 }
 771         }
 772
 773         /**
 774          * Generate a diff, no caching
 775          *
 776          * @param $otext String: old text, must be already segmented
 777          * @param $ntext String: new text, must be already segmented
 778          */
 779         function generateDiffBody( $otext, $ntext ) {
 780                 global $wgExternalDiffEngine, $wgContLang;
 781
 782         wfProfileIn( __METHOD__ );
 783
 784                 $otext = str_replace( "\r\n", "\n", $otext );
 785                 $ntext = str_replace( "\r\n", "\n", $ntext );
 786
 787                 $this->initDiffEngines();
 788
 789                 if ( $wgExternalDiffEngine == 'wikidiff' && function_exists( 'wikidiff_do_diff' ) ) {
 790                         # For historical reasons, external diff engine expects
 791                         # input text to be HTML-escaped already
 792                         $otext = htmlspecialchars ( $wgContLang->segmentForDiff( $otext ) );
 793                         $ntext = htmlspecialchars ( $wgContLang->segmentForDiff( $ntext ) );
 794                         return $wgContLang->unsegmentForDiff( wikidiff_do_diff( $otext, $ntext, 2 ) ) .
 795                         $this->debug( 'wikidiff1' );
 796                 }
 797
 798                 if ( $wgExternalDiffEngine == 'wikidiff2' && function_exists( 'wikidiff2_do_diff' ) ) {
 799                         # Better external diff engine, the 2 may some day be dropped
 800                         # This one does the escaping and segmenting itself
 801                         wfProfileIn( 'wikidiff2_do_diff' );
 802                         $text = wikidiff2_do_diff( $otext, $ntext, 2 );
 803                         $text .= $this->debug( 'wikidiff2' );
 804                         wfProfileOut( 'wikidiff2_do_diff' );
 805                         return $text;
 806                 }
 807                 if ( $wgExternalDiffEngine != 'wikidiff3' && $wgExternalDiffEngine !== false ) {
 808                         # Diff via the shell
 809                         global $wgTmpDirectory;
 810                         $tempName1 = tempnam( $wgTmpDirectory, 'diff_' );
 811                         $tempName2 = tempnam( $wgTmpDirectory, 'diff_' );
 812
 813                         $tempFile1 = fopen( $tempName1, "w" );
 814                         if ( !$tempFile1 ) {
 815                                 wfProfileOut( __METHOD__ );
 816                                 return false;
 817                         }
 818                         $tempFile2 = fopen( $tempName2, "w" );
 819                         if ( !$tempFile2 ) {
 820                                 wfProfileOut( __METHOD__ );
 821                                 return false;
 822                         }
 823                         fwrite( $tempFile1, $otext );
 824                         fwrite( $tempFile2, $ntext );
 825                         fclose( $tempFile1 );
 826                         fclose( $tempFile2 );
 827                         $cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
 828                         wfProfileIn( __METHOD__ . "-shellexec" );
 829                         $difftext = wfShellExec( $cmd );
 830                         $difftext .= $this->debug( "external $wgExternalDiffEngine" );
 831                         wfProfileOut( __METHOD__ . "-shellexec" );
 832                         unlink( $tempName1 );
 833                         unlink( $tempName2 );
 834                         wfProfileOut( __METHOD__ );
 835                         return $difftext;
 836                 }
 837
 838                 # Native PHP diff
 839                 $ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) );
 840                 $nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) );
 841                 $diffs = new Diff( $ota, $nta );
 842                 $formatter = new TableDiffFormatter();
 843                 $difftext = $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) ) .
 844                 wfProfileOut( __METHOD__ );
 845                 return $difftext;
 846         }
 847
 848         /**
 849          * Generate a debug comment indicating diff generating time,
 850          * server node, and generator backend.
 851          */
 852         protected function debug( $generator = "internal" ) {
 853                 global $wgShowHostnames;
 854                 if ( !$this->enableDebugComment ) {
 855                         return '';
 856                 }
 857                 $data = array( $generator );
 858                 if ( $wgShowHostnames ) {
 859                         $data[] = wfHostname();
 860                 }
 861                 $data[] = wfTimestamp( TS_DB );
 862                 return "<!-- diff generator: " .
 863                 implode( " ",
 864                 array_map(
 865                                         "htmlspecialchars",
 866                 $data ) ) .
 867                         " -->\n";
 868         }
 869
 870         /**
 871          * Replace line numbers with the text in the user's language
 872          */
 873         function localiseLineNumbers( $text ) {
 874                 return preg_replace_callback( '/<!--LINE (\d+)-->/',
 875                 array( &$this, 'localiseLineNumbersCb' ), $text );
 876         }
 877
 878         function localiseLineNumbersCb( $matches ) {
 879                 global $wgLang;
 880                 if ( $matches[1] === '1' && $this->mReducedLineNumbers ) return '';
 881                 return wfMsgExt( 'lineno', 'escape', $wgLang->formatNum( $matches[1] ) );
 882         }
 883
 884
 885         /**
 886          * If there are revisions between the ones being compared, return a note saying so.
 887          * @return string
 888          */
 889         function getMultiNotice() {
 890                 if ( !is_object( $this->mOldRev ) || !is_object( $this->mNewRev ) ) {
 891                         return '';
 892                 } elseif ( !$this->mOldPage->equals( $this->mNewPage ) ) {
 893                         // Comparing two different pages? Count would be meaningless.
 894                         return '';
 895                 }
 896
 897                 if ( $this->mOldRev->getTimestamp() > $this->mNewRev->getTimestamp() ) {
 898                         $oldRev = $this->mNewRev; // flip
 899                         $newRev = $this->mOldRev; // flip
 900                 } else { // normal case
 901                         $oldRev = $this->mOldRev;
 902                         $newRev = $this->mNewRev;
 903                 }
 904
 905                 $nEdits = $this->mTitle->countRevisionsBetween( $oldRev, $newRev );
 906                 if ( $nEdits > 0 ) {
 907                         $limit = 100; // use diff-multi-manyusers if too many users
 908                         $numUsers = $this->mTitle->countAuthorsBetween( $oldRev, $newRev, $limit );
 909                         return self::intermediateEditsMsg( $nEdits, $numUsers, $limit );
 910                 }
 911                 return ''; // nothing
 912         }
 913
 914         /**
 915          * Get a notice about how many intermediate edits and users there are
 916          * @param $numEdits int
 917          * @param $numUsers int
 918          * @param $limit int
 919          * @return string
 920          */
 921         public static function intermediateEditsMsg( $numEdits, $numUsers, $limit ) {
 922                 global $wgLang;
 923                 if ( $numUsers > $limit ) {
 924                         $msg = 'diff-multi-manyusers';
 925                         $numUsers = $limit;
 926                 } else {
 927                         $msg = 'diff-multi';
 928                 }
 929                 return wfMsgExt( $msg, 'parseinline',
 930                         $wgLang->formatnum( $numEdits ), $wgLang->formatnum( $numUsers ) );
 931         }
 932
 933         /**
 934          * Add the header to a diff body
 935          *
 936          * @return string
 937          */
 938         function addHeader( $diff, $otitle, $ntitle, $multi = '', $notice = '' ) {
 939                 // shared.css sets diff in interface language/dir,
 940                 // but the actual content should be in the page language/dir
 941                 $pageLang = $this->mTitle->getPageLanguage();
 942                 $tableClass = 'diff diff-contentalign-' . htmlspecialchars( $pageLang->alignStart() );
 943                 $header = "<table class='$tableClass'>";
 944                 if ( $diff ) { // Safari/Chrome show broken output if cols not used
 945                         $header .= "
 946                         <col class='diff-marker' />
 947                         <col class='diff-content' />
 948                         <col class='diff-marker' />
 949                         <col class='diff-content' />";
 950                         $colspan = 2;
 951                         $multiColspan = 4;
 952                 } else {
 953                         $colspan = 1;
 954                         $multiColspan = 2;
 955                 }
 956                 $header .= "
 957                 <tr valign='top'>
 958                 <td colspan='$colspan' class='diff-otitle'>{$otitle}</td>
 959                 <td colspan='$colspan' class='diff-ntitle'>{$ntitle}</td>
 960                 </tr>";
 961
 962                 if ( $multi != '' ) {
 963                         $header .= "<tr><td colspan='{$multiColspan}' align='center' class='diff-multi'>{$multi}</td></tr>";
 964                 }
 965                 if ( $notice != '' ) {
 966                         $header .= "<tr><td colspan='{$multiColspan}' align='center'>{$notice}</td></tr>";
 967                 }
 968
 969                 return $header . $diff . "</table>";
 970         }
 971
 972         /**
 973          * Use specified text instead of loading from the database
 974          */
 975         function setText( $oldText, $newText ) {
 976                 $this->mOldtext = $oldText;
 977                 $this->mNewtext = $newText;
 978                 $this->mTextLoaded = 2;
 979                 $this->mRevisionsLoaded = true;
 980         }
 981
 982         /**
 983          * Load revision metadata for the specified articles. If newid is 0, then compare
 984          * the old article in oldid to the current article; if oldid is 0, then
 985          * compare the current article to the immediately previous one (ignoring the
 986          * value of newid).
 987          *
 988          * If oldid is false, leave the corresponding revision object set
 989          * to false. This is impossible via ordinary user input, and is provided for
 990          * API convenience.
 991          *
 992          * @return bool
 993          */
 994         function loadRevisionData() {
 995                 global $wgLang, $wgUser;
 996                 if ( $this->mRevisionsLoaded ) {
 997                         return true;
 998                 } else {
 999                         // Whether it succeeds or fails, we don't want to try again
1000                         $this->mRevisionsLoaded = true;
1001                 }
1002
1003                 // Load the new revision object
1004                 $this->mNewRev = $this->mNewid
1005                         ? Revision::newFromId( $this->mNewid )
1006                         : Revision::newFromTitle( $this->mTitle );
1007                 if ( !$this->mNewRev instanceof Revision ) {
1008                         return false;
1009                 }
1010
1011                 // Update the new revision ID in case it was 0 (makes life easier doing UI stuff)
1012                 $this->mNewid = $this->mNewRev->getId();
1013
1014                 // Check if page is editable
1015                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
1016
1017                 // Set assorted variables
1018                 $timestamp = $wgLang->timeanddate( $this->mNewRev->getTimestamp(), true );
1019                 $dateofrev = $wgLang->date( $this->mNewRev->getTimestamp(), true );
1020                 $timeofrev = $wgLang->time( $this->mNewRev->getTimestamp(), true );
1021                 $this->mNewPage = $this->mNewRev->getTitle();
1022                 if ( $this->mNewRev->isCurrent() ) {
1023                         $newLink = $this->mNewPage->escapeLocalUrl( array(
1024                                 'oldid' => $this->mNewid
1025                         ) );
1026                         $this->mPagetitle = htmlspecialchars( wfMsg(
1027                                 'currentrev-asof',
1028                                 $timestamp,
1029                                 $dateofrev,
1030                                 $timeofrev
1031                         ) );
1032                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
1033                                 'action' => 'edit'
1034                         ) );
1035
1036                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
1037                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1038                 } else {
1039                         $newLink = $this->mNewPage->escapeLocalUrl( array(
1040                                 'oldid' => $this->mNewid
1041                         ) );
1042                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
1043                                 'action' => 'edit',
1044                                 'oldid' => $this->mNewid
1045                         ) );
1046                         $this->mPagetitle = htmlspecialchars( wfMsg(
1047                                 'revisionasof',
1048                                 $timestamp,
1049                                 $dateofrev,
1050                                 $timeofrev
1051                         ) );
1052
1053                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
1054                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1055                 }
1056                 if ( !$this->mNewRev->userCan( Revision::DELETED_TEXT ) ) {
1057                         $this->mNewtitle = "<span class='history-deleted'>{$this->mPagetitle}</span>";
1058                 } elseif ( $this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
1059                         $this->mNewtitle = "<span class='history-deleted'>{$this->mNewtitle}</span>";
1060                 }
1061
1062                 // Load the old revision object
1063                 $this->mOldRev = false;
1064                 if ( $this->mOldid ) {
1065                         $this->mOldRev = Revision::newFromId( $this->mOldid );
1066                 } elseif ( $this->mOldid === 0 ) {
1067                         $rev = $this->mNewRev->getPrevious();
1068                         if ( $rev ) {
1069                                 $this->mOldid = $rev->getId();
1070                                 $this->mOldRev = $rev;
1071                         } else {
1072                                 // No previous revision; mark to show as first-version only.
1073                                 $this->mOldid = false;
1074                                 $this->mOldRev = false;
1075                         }
1076                 } /* elseif ( $this->mOldid === false ) leave mOldRev false; */
1077
1078                 if ( is_null( $this->mOldRev ) ) {
1079                         return false;
1080                 }
1081
1082                 if ( $this->mOldRev ) {
1083                         $this->mOldPage = $this->mOldRev->getTitle();
1084
1085                         $t = $wgLang->timeanddate( $this->mOldRev->getTimestamp(), true );
1086                         $dateofrev = $wgLang->date( $this->mOldRev->getTimestamp(), true );
1087                         $timeofrev = $wgLang->time( $this->mOldRev->getTimestamp(), true );
1088                         $oldLink = $this->mOldPage->escapeLocalUrl( array(
1089                                 'oldid' => $this->mOldid
1090                         ) );
1091                         $oldEdit = $this->mOldPage->escapeLocalUrl( array(
1092                                 'action' => 'edit',
1093                                 'oldid' => $this->mOldid
1094                         ) );
1095                         $this->mOldPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $t, $dateofrev, $timeofrev ) );
1096
1097                         $this->mOldtitle = "<a href='$oldLink'>{$this->mOldPagetitle}</a>"
1098                         . " (<a href='$oldEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1099                         // Add an "undo" link
1100                         if ( $editable && !$this->mOldRev->isDeleted( Revision::DELETED_TEXT ) && !$this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
1101                                 $undoLink = Html::element( 'a', array(
1102                                         'href' => $this->mNewPage->getLocalUrl( array(
1103                                                 'action' => 'edit',
1104                                                 'undoafter' => $this->mOldid,
1105                                                 'undo' => $this->mNewid ) ),
1106                                         'title' => $wgUser->getSkin()->titleAttrib( 'undo' )
1107                                 ), wfMsg( 'editundo' ) );
1108                                 $this->mNewtitle .= ' (' . $undoLink . ')';
1109                         }
1110
1111                         if ( !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
1112                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldPagetitle . '</span>';
1113                         } elseif ( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
1114                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldtitle . '</span>';
1115                         }
1116                 }
1117
1118                 return true;
1119         }
1120
1121         /**
1122          * Load the text of the revisions, as well as revision data.
1123          *
1124          * @return bool
1125          */
1126         function loadText() {
1127                 if ( $this->mTextLoaded == 2 ) {
1128                         return true;
1129                 } else {
1130                         // Whether it succeeds or fails, we don't want to try again
1131                         $this->mTextLoaded = 2;
1132                 }
1133
1134                 if ( !$this->loadRevisionData() ) {
1135                         return false;
1136                 }
1137                 if ( $this->mOldRev ) {
1138                         $this->mOldtext = $this->mOldRev->getText( Revision::FOR_THIS_USER );
1139                         if ( $this->mOldtext === false ) {
1140                                 return false;
1141                         }
1142                 }
1143                 if ( $this->mNewRev ) {
1144                         $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1145                         if ( $this->mNewtext === false ) {
1146                                 return false;
1147                         }
1148                 }
1149                 return true;
1150         }
1151
1152         /**
1153          * Load the text of the new revision, not the old one
1154          *
1155          * @return bool
1156          */
1157         function loadNewText() {
1158                 if ( $this->mTextLoaded >= 1 ) {
1159                         return true;
1160                 } else {
1161                         $this->mTextLoaded = 1;
1162                 }
1163                 if ( !$this->loadRevisionData() ) {
1164                         return false;
1165                 }
1166                 $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1167                 return true;
1168         }
1169 }