includes/diff/DifferenceInterface.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, $mTitle;
  26         var $mOldtitle, $mNewtitle, $mPagetitle;
  27         var $mOldtext, $mNewtext;
  28         var $mOldPage, $mNewPage;
  29         var $mRcidMarkPatrolled;
  30         var $mOldRev, $mNewRev;
  31         var $mRevisionsLoaded = false; // Have the revisions been loaded
  32         var $mTextLoaded = 0; // How many text blobs have been loaded, 0, 1 or 2?
  33         var $mCacheHit = false; // Was the diff fetched from cache?
  34
  35         /**
  36          * Set this to true to add debug info to the HTML output.
  37          * Warning: this may cause RSS readers to spuriously mark articles as "new"
  38          * (bug 20601)
  39          */
  40         var $enableDebugComment = false;
  41
  42         // If true, line X is not displayed when X is 1, for example to increase
  43         // readability and conserve space with many small diffs.
  44         protected $mReducedLineNumbers = false;
  45
  46         protected $unhide = false; # show rev_deleted content if allowed
  47         /**#@-*/
  48
  49         /**
  50          * Constructor
  51          * @param $titleObj Title object that the diff is associated with
  52          * @param $old Integer: old ID we want to show and diff with.
  53          * @param $new String: either 'prev' or 'next'.
  54          * @param $rcid Integer: ??? FIXME (default 0)
  55          * @param $refreshCache boolean If set, refreshes the diff cache
  56          * @param $unhide boolean If set, allow viewing deleted revs
  57          */
  58         function __construct( $titleObj = null, $old = 0, $new = 0, $rcid = 0,
  59                 $refreshCache = false, $unhide = false )
  60         {
  61                 if ( $titleObj ) {
  62                         $this->mTitle = $titleObj;
  63                 } else {
  64                         global $wgTitle;
  65                         $this->mTitle = $wgTitle;
  66                 }
  67                 wfDebug("DifferenceEngine old '$old' new '$new' rcid '$rcid'\n");
  68
  69                 if ( 'prev' === $new ) {
  70                         # Show diff between revision $old and the previous one.
  71                         # Get previous one from DB.
  72                         $this->mNewid = intval($old);
  73                         $this->mOldid = $this->mTitle->getPreviousRevisionID( $this->mNewid );
  74                 } elseif ( 'next' === $new ) {
  75                         # Show diff between revision $old and the next one.
  76                         # Get next one from DB.
  77                         $this->mOldid = intval($old);
  78                         $this->mNewid = $this->mTitle->getNextRevisionID( $this->mOldid );
  79                         if ( false === $this->mNewid ) {
  80                                 # if no result, NewId points to the newest old revision. The only newer
  81                                 # revision is cur, which is "0".
  82                                 $this->mNewid = 0;
  83                         }
  84                 } else {
  85                         $this->mOldid = intval($old);
  86                         $this->mNewid = intval($new);
  87                         wfRunHooks( 'NewDifferenceEngine', array(&$titleObj, &$this->mOldid, &$this->mNewid, $old, $new) );
  88                 }
  89                 $this->mRcidMarkPatrolled = intval($rcid);  # force it to be an integer
  90                 $this->mRefreshCache = $refreshCache;
  91                 $this->unhide = $unhide;
  92         }
  93
  94         function setReducedLineNumbers( $value = true ) {
  95                 $this->mReducedLineNumbers = $value;
  96         }
  97
  98         function getTitle() {
  99                 return $this->mTitle;
 100         }
 101
 102         function wasCacheHit() {
 103                 return $this->mCacheHit;
 104         }
 105
 106         function getOldid() {
 107                 return $this->mOldid;
 108         }
 109
 110         function getNewid() {
 111                 return $this->mNewid;
 112         }
 113
 114         function showDiffPage( $diffOnly = false ) {
 115                 global $wgUser, $wgOut, $wgUseExternalEditor, $wgUseRCPatrol;
 116                 wfProfileIn( __METHOD__ );
 117
 118
 119                 # If external diffs are enabled both globally and for the user,
 120                 # we'll use the application/x-external-editor interface to call
 121                 # an external diff tool like kompare, kdiff3, etc.
 122                 if($wgUseExternalEditor && $wgUser->getOption('externaldiff')) {
 123                         global $wgInputEncoding,$wgServer,$wgScript,$wgLang;
 124                         $wgOut->disable();
 125                         header ( "Content-type: application/x-external-editor; charset=".$wgInputEncoding );
 126                         $url1=$this->mTitle->getFullURL( array(
 127                                 'action' => 'raw',
 128                                 'oldid' => $this->mOldid
 129                         ) );
 130                         $url2=$this->mTitle->getFullURL( array(
 131                                 'action' => 'raw',
 132                                 'oldid' => $this->mNewid
 133                         ) );
 134                         $special=$wgLang->getNsText(NS_SPECIAL);
 135                         $control=<<<CONTROL
 136                         [Process]
 137                         Type=Diff text
 138                         Engine=MediaWiki
 139                         Script={$wgServer}{$wgScript}
 140                         Special namespace={$special}
 141
 142                         [File]
 143                         Extension=wiki
 144                         URL=$url1
 145
 146                         [File 2]
 147                         Extension=wiki
 148                         URL=$url2
 149 CONTROL;
 150                         echo($control);
 151                         return;
 152                 }
 153
 154                 $wgOut->setArticleFlag( false );
 155                 if ( !$this->loadRevisionData() ) {
 156                         $t = $this->mTitle->getPrefixedText();
 157                         $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
 158                         $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
 159                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", $d );
 160                         wfProfileOut( __METHOD__ );
 161                         return;
 162                 }
 163
 164                 wfRunHooks( 'DiffViewHeader', array( $this, $this->mOldRev, $this->mNewRev ) );
 165
 166                 if ( $this->mNewRev->isCurrent() ) {
 167                         $wgOut->setArticleFlag( true );
 168                 }
 169
 170                 # mOldid is false if the difference engine is called with a "vague" query for
 171                 # a diff between a version V and its previous version V' AND the version V
 172                 # is the first version of that article. In that case, V' does not exist.
 173                 if ( $this->mOldid === false ) {
 174                         $this->showFirstRevision();
 175                         $this->renderNewRevision();  // should we respect $diffOnly here or not?
 176                         wfProfileOut( __METHOD__ );
 177                         return;
 178                 }
 179
 180                 $wgOut->suppressQuickbar();
 181
 182                 $oldTitle = $this->mOldPage->getPrefixedText();
 183                 $newTitle = $this->mNewPage->getPrefixedText();
 184                 if( $oldTitle == $newTitle ) {
 185                         $wgOut->setPageTitle( $newTitle );
 186                 } else {
 187                         $wgOut->setPageTitle( $oldTitle . ', ' . $newTitle );
 188                 }
 189                 if ( $this->mNewPage->equals( $this->mOldPage ) ) {
 190                         $wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
 191                 } else {
 192                         $wgOut->setSubtitle( wfMsgExt( 'difference-multipage', array( 'parseinline' ) ) );
 193                 }
 194                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
 195
 196                 if ( !$this->mOldPage->userCanRead() || !$this->mNewPage->userCanRead() ) {
 197                         $wgOut->loginToUse();
 198                         $wgOut->output();
 199                         $wgOut->disable();
 200                         wfProfileOut( __METHOD__ );
 201                         return;
 202                 }
 203
 204                 $sk = $wgUser->getSkin();
 205
 206                 // Check if page is editable
 207                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
 208                 if ( $editable && $this->mNewRev->isCurrent() && $wgUser->isAllowed( 'rollback' ) ) {
 209                         $rollback = '&#160;&#160;&#160;' . $sk->generateRollback( $this->mNewRev );
 210                 } else {
 211                         $rollback = '';
 212                 }
 213
 214                 // Prepare a change patrol link, if applicable
 215                 if( $wgUseRCPatrol && $this->mTitle->userCan('patrol') ) {
 216                         // If we've been given an explicit change identifier, use it; saves time
 217                         if( $this->mRcidMarkPatrolled ) {
 218                                 $rcid = $this->mRcidMarkPatrolled;
 219                                 $rc = RecentChange::newFromId( $rcid );
 220                                 // Already patrolled?
 221                                 $rcid = is_object($rc) && !$rc->getAttribute('rc_patrolled') ? $rcid : 0;
 222                         } else {
 223                                 // Look for an unpatrolled change corresponding to this diff
 224                                 $db = wfGetDB( DB_SLAVE );
 225                                 $change = RecentChange::newFromConds(
 226                                         array(
 227                                         // Redundant user,timestamp condition so we can use the existing index
 228                                                 'rc_user_text'  => $this->mNewRev->getRawUserText(),
 229                                                 'rc_timestamp'  => $db->timestamp( $this->mNewRev->getTimestamp() ),
 230                                                 'rc_this_oldid' => $this->mNewid,
 231                                                 'rc_last_oldid' => $this->mOldid,
 232                                                 'rc_patrolled'  => 0
 233                                         ),
 234                                         __METHOD__
 235                                 );
 236                                 if( $change instanceof RecentChange ) {
 237                                         $rcid = $change->mAttribs['rc_id'];
 238                                         $this->mRcidMarkPatrolled = $rcid;
 239                                 } else {
 240                                         // None found
 241                                         $rcid = 0;
 242                                 }
 243                         }
 244                         // Build the link
 245                         if( $rcid ) {
 246                                 $token = $wgUser->editToken();
 247                                 $patrol = ' <span class="patrollink">[' . $sk->link(
 248                                         $this->mTitle,
 249                                         wfMsgHtml( 'markaspatrolleddiff' ),
 250                                         array(),
 251                                         array(
 252                                                 'action' => 'markpatrolled',
 253                                                 'rcid' => $rcid,
 254                                                 'token' => $token,
 255                                         ),
 256                                         array(
 257                                                 'known',
 258                                                 'noclasses'
 259                                         )
 260                                 ) . ']</span>';
 261                         } else {
 262                                 $patrol = '';
 263                         }
 264                 } else {
 265                         $patrol = '';
 266                 }
 267
 268                 # Carry over 'diffonly' param via navigation links
 269                 if( $diffOnly != $wgUser->getBoolOption('diffonly') ) {
 270                         $query['diffonly'] = $diffOnly;
 271                 }
 272
 273                 # Make "previous revision link"
 274                 $query['diff'] = 'prev';
 275                 $query['oldid'] = $this->mOldid;
 276                 # Cascade unhide param in links for easy deletion browsing
 277                 if( $this->unhide ) {
 278                         $query['unhide'] = 1;
 279                 }
 280                 if( !$this->mOldRev->getPrevious() ) {
 281                         $prevlink = '&#160;';
 282                 } else {
 283                         $prevlink = $sk->link(
 284                                 $this->mTitle,
 285                                 wfMsgHtml( 'previousdiff' ),
 286                                 array(
 287                                         'id' => 'differences-prevlink'
 288                                 ),
 289                                 $query,
 290                                 array(
 291                                         'known',
 292                                         'noclasses'
 293                                 )
 294                         );
 295                 }
 296
 297                 # Make "next revision link"
 298                 $query['diff'] = 'next';
 299                 $query['oldid'] = $this->mNewid;
 300                 # Skip next link on the top revision
 301                 if( $this->mNewRev->isCurrent() ) {
 302                         $nextlink = '&#160;';
 303                 } else {
 304                         $nextlink = $sk->link(
 305                                 $this->mTitle,
 306                                 wfMsgHtml( 'nextdiff' ),
 307                                 array(
 308                                         'id' => 'differences-nextlink'
 309                                 ),
 310                                 $query,
 311                                 array(
 312                                         'known',
 313                                         'noclasses'
 314                                 )
 315                         );
 316                 }
 317
 318                 $oldminor = '';
 319                 $newminor = '';
 320
 321                 if( $this->mOldRev->isMinor() ) {
 322                         $oldminor = ChangesList::flag( 'minor' );
 323                 }
 324                 if( $this->mNewRev->isMinor() ) {
 325                         $newminor = ChangesList::flag( 'minor' );
 326                 }
 327
 328                 # Handle RevisionDelete links...
 329                 $ldel = $this->revisionDeleteLink( $this->mOldRev );
 330                 $rdel = $this->revisionDeleteLink( $this->mNewRev );
 331
 332                 $oldHeader = '<div id="mw-diff-otitle1"><strong>'.$this->mOldtitle.'</strong></div>' .
 333                         '<div id="mw-diff-otitle2">' .
 334                                 $sk->revUserTools( $this->mOldRev, !$this->unhide ).'</div>' .
 335                         '<div id="mw-diff-otitle3">' . $oldminor .
 336                                 $sk->revComment( $this->mOldRev, !$diffOnly, !$this->unhide ).$ldel.'</div>' .
 337                         '<div id="mw-diff-otitle4">' . $prevlink .'</div>';
 338                 $newHeader = '<div id="mw-diff-ntitle1"><strong>'.$this->mNewtitle.'</strong></div>' .
 339                         '<div id="mw-diff-ntitle2">' . $sk->revUserTools( $this->mNewRev, !$this->unhide ) .
 340                                 " $rollback</div>" .
 341                         '<div id="mw-diff-ntitle3">' . $newminor .
 342                                 $sk->revComment( $this->mNewRev, !$diffOnly, !$this->unhide ).$rdel.'</div>' .
 343                         '<div id="mw-diff-ntitle4">' . $nextlink . $patrol . '</div>';
 344
 345                 # Check if this user can see the revisions
 346                 $allowed = $this->mOldRev->userCan(Revision::DELETED_TEXT)
 347                         && $this->mNewRev->userCan(Revision::DELETED_TEXT);
 348                 # Check if one of the revisions is deleted/suppressed
 349                 $deleted = $suppressed = false;
 350                 if( $this->mOldRev->isDeleted(Revision::DELETED_TEXT) ) {
 351                         $deleted = true; // old revisions text is hidden
 352                         if( $this->mOldRev->isDeleted(Revision::DELETED_RESTRICTED) )
 353                                 $suppressed = true; // also suppressed
 354                 }
 355                 if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
 356                         $deleted = true; // new revisions text is hidden
 357                         if( $this->mNewRev->isDeleted(Revision::DELETED_RESTRICTED) )
 358                                 $suppressed = true; // also suppressed
 359                 }
 360                 # If the diff cannot be shown due to a deleted revision, then output
 361                 # the diff header and links to unhide (if available)...
 362                 if( $deleted && (!$this->unhide || !$allowed) ) {
 363                         $this->showDiffStyle();
 364                         $multi = $this->getMultiNotice();
 365                         $wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) );
 366                         if( !$allowed ) {
 367                                 $msg = $suppressed ? 'rev-suppressed-no-diff' : 'rev-deleted-no-diff';
 368                                 # Give explanation for why revision is not visible
 369                                 $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1\n</div>\n",
 370                                         array( $msg ) );
 371                         } else {
 372                                 # Give explanation and add a link to view the diff...
 373                                 $link = $this->mTitle->getFullUrl( array(
 374                                         'diff' => $this->mNewid,
 375                                         'oldid' => $this->mOldid,
 376                                         'unhide' => 1
 377                                 ) );
 378                                 $msg = $suppressed ? 'rev-suppressed-unhide-diff' : 'rev-deleted-unhide-diff';
 379                                 $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1\n</div>\n", array( $msg, $link ) );
 380                         }
 381                 # Otherwise, output a regular diff...
 382                 } else {
 383                         # Add deletion notice if the user is viewing deleted content
 384                         $notice = '';
 385                         if( $deleted ) {
 386                                 $msg = $suppressed ? 'rev-suppressed-diff-view' : 'rev-deleted-diff-view';
 387                                 $notice = "<div class='mw-warning plainlinks'>\n".wfMsgExt($msg,'parseinline')."</div>\n";
 388                         }
 389                         $this->showDiff( $oldHeader, $newHeader, $notice );
 390                         if( !$diffOnly ) {
 391                                 $this->renderNewRevision();
 392                         }
 393                 }
 394                 wfProfileOut( __METHOD__ );
 395         }
 396
 397         protected function revisionDeleteLink( $rev ) {
 398                 global $wgUser;
 399                 $link = '';
 400                 $canHide = $wgUser->isAllowed( 'deleterevision' );
 401                 // Show del/undel link if:
 402                 // (a) the user can delete revisions, or
 403                 // (b) the user can view deleted revision *and* this one is deleted
 404                 if( $canHide || ($rev->getVisibility() && $wgUser->isAllowed( 'deletedhistory' )) ) {
 405                         $sk = $wgUser->getSkin();
 406                         if( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 407                                 $link = $sk->revDeleteLinkDisabled( $canHide ); // revision was hidden from sysops
 408                         } else {
 409                                 $query = array(
 410                                         'type'   => 'revision',
 411                                         'target' => $rev->mTitle->getPrefixedDbkey(),
 412                                         'ids'    => $rev->getId()
 413                                 );
 414                                 $link = $sk->revDeleteLink( $query,
 415                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ), $canHide );
 416                         }
 417                         $link = '&#160;&#160;&#160;' . $link . ' ';
 418                 }
 419                 return $link;
 420         }
 421
 422         /**
 423          * Show the new revision of the page.
 424          */
 425         function renderNewRevision() {
 426                 global $wgOut, $wgUser;
 427                 wfProfileIn( __METHOD__ );
 428
 429                 $wgOut->addHTML( "<hr /><h2>{$this->mPagetitle}</h2>\n" );
 430                 # Add deleted rev tag if needed
 431                 if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
 432                         $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1\n</div>\n", 'rev-deleted-text-permission' );
 433                 } else if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
 434                         $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1\n</div>\n", 'rev-deleted-text-view' );
 435                 }
 436
 437                 $pCache = true;
 438                 if( !$this->mNewRev->isCurrent() ) {
 439                         $oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false );
 440                         $pCache = false;
 441                 }
 442
 443                 $this->loadNewText();
 444                 if( is_object( $this->mNewRev ) ) {
 445                         $wgOut->setRevisionId( $this->mNewRev->getId() );
 446                 }
 447
 448                 if( $this->mTitle->isCssJsSubpage() || $this->mTitle->isCssOrJsPage() ) {
 449                         // Stolen from Article::view --AG 2007-10-11
 450                         // Give hooks a chance to customise the output
 451                         if( wfRunHooks( 'ShowRawCssJs', array( $this->mNewtext, $this->mTitle, $wgOut ) ) ) {
 452                                 // Wrap the whole lot in a <pre> and don't parse
 453                                 $m = array();
 454                                 preg_match( '!\.(css|js)$!u', $this->mTitle->getText(), $m );
 455                                 $wgOut->addHTML( "<pre class=\"mw-code mw-{$m[1]}\" dir=\"ltr\">\n" );
 456                                 $wgOut->addHTML( htmlspecialchars( $this->mNewtext ) );
 457                                 $wgOut->addHTML( "\n</pre>\n" );
 458                         }
 459                 } elseif( wfRunHooks( 'ArticleContentOnDiff', array( $this, &$wgOut ) ) ) {
 460                         if( $pCache ) {
 461                                 $article = new Article( $this->mTitle, 0 );
 462                                 $pOutput = ParserCache::singleton()->get( $article, $wgOut->parserOptions() );
 463                                 if( $pOutput ) {
 464                                         $wgOut->addParserOutput( $pOutput );
 465                                 } else {
 466                                         $article->doViewParse();
 467                                 }
 468                         } else {
 469                                 $wgOut->addWikiTextTidy( $this->mNewtext );
 470                         }
 471                         if( is_object( $this->mNewRev ) && !$this->mNewRev->isCurrent() ) {
 472                                 $wgOut->parserOptions()->setEditSection( $oldEditSectionSetting );
 473                         }
 474                 }
 475
 476                 # Add redundant patrol link on bottom...
 477                 if( $this->mRcidMarkPatrolled && $this->mTitle->quickUserCan('patrol') ) {
 478                         $sk = $wgUser->getSkin();
 479                         $token = $wgUser->editToken();
 480                         $wgOut->addHTML(
 481                                 "<div class='patrollink'>[" . $sk->link(
 482                                         $this->mTitle,
 483                                         wfMsgHtml( 'markaspatrolleddiff' ),
 484                                         array(),
 485                                         array(
 486                                                 'action' => 'markpatrolled',
 487                                                 'rcid' => $this->mRcidMarkPatrolled,
 488                                                 'token' => $token,
 489                                         )
 490                                 ) . ']</div>'
 491                          );
 492                 }
 493
 494                 wfProfileOut( __METHOD__ );
 495         }
 496
 497         /**
 498          * Show the first revision of an article. Uses normal diff headers in
 499          * contrast to normal "old revision" display style.
 500          */
 501         function showFirstRevision() {
 502                 global $wgOut, $wgUser;
 503                 wfProfileIn( __METHOD__ );
 504
 505                 # Get article text from the DB
 506                 #
 507                 if ( ! $this->loadNewText() ) {
 508                         $t = $this->mTitle->getPrefixedText();
 509                         $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
 510                         $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
 511                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", $d );
 512                         wfProfileOut( __METHOD__ );
 513                         return;
 514                 }
 515                 if ( $this->mNewRev->isCurrent() ) {
 516                         $wgOut->setArticleFlag( true );
 517                 }
 518
 519                 # Check if user is allowed to look at this page. If not, bail out.
 520                 #
 521                 if ( !$this->mTitle->userCanRead() ) {
 522                         $wgOut->loginToUse();
 523                         $wgOut->output();
 524                         wfProfileOut( __METHOD__ );
 525                         throw new MWException("Permission Error: you do not have access to view this page");
 526                 }
 527
 528                 # Prepare the header box
 529                 #
 530                 $sk = $wgUser->getSkin();
 531
 532                 $next = $this->mTitle->getNextRevisionID( $this->mNewid );
 533                 if( !$next ) {
 534                         $nextlink = '';
 535                 } else {
 536                         $nextlink = '<br />' . $sk->link(
 537                                 $this->mTitle,
 538                                 wfMsgHtml( 'nextdiff' ),
 539                                 array(
 540                                         'id' => 'differences-nextlink'
 541                                 ),
 542                                 array(
 543                                         'diff' => 'next',
 544                                         'oldid' => $this->mNewid,
 545                                 ),
 546                                 array(
 547                                         'known',
 548                                         'noclasses'
 549                                 )
 550                         );
 551                 }
 552                 $header = "<div class=\"firstrevisionheader\" style=\"text-align: center\">" .
 553                         $sk->revUserTools( $this->mNewRev ) . "<br />" . $sk->revComment( $this->mNewRev ) . $nextlink . "</div>\n";
 554
 555                 $wgOut->addHTML( $header );
 556
 557                 $wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
 558                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
 559
 560                 wfProfileOut( __METHOD__ );
 561         }
 562
 563         /**
 564          * Get the diff text, send it to $wgOut
 565          * Returns false if the diff could not be generated, otherwise returns true
 566          */
 567         function showDiff( $otitle, $ntitle, $notice = '' ) {
 568                 global $wgOut;
 569                 $diff = $this->getDiff( $otitle, $ntitle, $notice );
 570                 if ( $diff === false ) {
 571                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>(fixme, bug)</nowiki>", '' );
 572                         return false;
 573                 } else {
 574                         $this->showDiffStyle();
 575                         $wgOut->addHTML( $diff );
 576                         return true;
 577                 }
 578         }
 579
 580         /**
 581          * Add style sheets and supporting JS for diff display.
 582          */
 583         function showDiffStyle() {
 584                 global $wgOut;
 585                 $wgOut->addModules( 'mediawiki.legacy.diff' );
 586         }
 587
 588         /**
 589          * Get complete diff table, including header
 590          *
 591          * @param $otitle Title: old title
 592          * @param $ntitle Title: new title
 593          * @param $notice String: HTML between diff header and body
 594          * @return mixed
 595          */
 596         function getDiff( $otitle, $ntitle, $notice = '' ) {
 597                 $body = $this->getDiffBody();
 598                 if ( $body === false ) {
 599                         return false;
 600                 } else {
 601                         $multi = $this->getMultiNotice();
 602                         return $this->addHeader( $body, $otitle, $ntitle, $multi, $notice );
 603                 }
 604         }
 605
 606         /**
 607          * Get the diff table body, without header
 608          *
 609          * @return mixed
 610          */
 611         function getDiffBody() {
 612                 global $wgMemc;
 613                 wfProfileIn( __METHOD__ );
 614                 $this->mCacheHit = true;
 615                 // Check if the diff should be hidden from this user
 616                 if ( !$this->loadRevisionData() )
 617                         return '';
 618                 if ( $this->mOldRev && !$this->mOldRev->userCan(Revision::DELETED_TEXT) ) {
 619                         return '';
 620                 } else if ( $this->mNewRev && !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
 621                         return '';
 622                 } else if ( $this->mOldRev && $this->mNewRev && $this->mOldRev->getID() == $this->mNewRev->getID() ) {
 623                         return '';
 624                 }
 625                 // Cacheable?
 626                 $key = false;
 627                 if ( $this->mOldid && $this->mNewid ) {
 628                         $key = wfMemcKey( 'diff', 'version', MW_DIFF_VERSION, 'oldid', $this->mOldid, 'newid', $this->mNewid );
 629                         // Try cache
 630                         if ( !$this->mRefreshCache ) {
 631                                 $difftext = $wgMemc->get( $key );
 632                                 if ( $difftext ) {
 633                                         wfIncrStats( 'diff_cache_hit' );
 634                                         $difftext = $this->localiseLineNumbers( $difftext );
 635                                         $difftext .= "\n<!-- diff cache key $key -->\n";
 636                                         wfProfileOut( __METHOD__ );
 637                                         return $difftext;
 638                                 }
 639                         } // don't try to load but save the result
 640                 }
 641                 $this->mCacheHit = false;
 642
 643                 // Loadtext is permission safe, this just clears out the diff
 644                 if ( !$this->loadText() ) {
 645                         wfProfileOut( __METHOD__ );
 646                         return false;
 647                 }
 648
 649                 $difftext = $this->generateDiffBody( $this->mOldtext, $this->mNewtext );
 650
 651                 // Save to cache for 7 days
 652                 if ( !wfRunHooks( 'AbortDiffCache', array( &$this ) ) ) {
 653                         wfIncrStats( 'diff_uncacheable' );
 654                 } else if ( $key !== false && $difftext !== false ) {
 655                         wfIncrStats( 'diff_cache_miss' );
 656                         $wgMemc->set( $key, $difftext, 7*86400 );
 657                 } else {
 658                         wfIncrStats( 'diff_uncacheable' );
 659                 }
 660                 // Replace line numbers with the text in the user's language
 661                 if ( $difftext !== false ) {
 662                         $difftext = $this->localiseLineNumbers( $difftext );
 663                 }
 664                 wfProfileOut( __METHOD__ );
 665                 return $difftext;
 666         }
 667
 668         /**
 669          * Make sure the proper modules are loaded before we try to
 670          * make the diff
 671          */
 672         private function initDiffEngines() {
 673                 global $wgExternalDiffEngine;
 674                 if ( $wgExternalDiffEngine == 'wikidiff' && !function_exists( 'wikidiff_do_diff' ) ) {
 675                         wfProfileIn( __METHOD__ . '-php_wikidiff.so' );
 676                         wfSuppressWarnings();
 677                         dl( 'php_wikidiff.so' );
 678                         wfRestoreWarnings();
 679                         wfProfileOut( __METHOD__ . '-php_wikidiff.so' );
 680                 }
 681                 else if ( $wgExternalDiffEngine == 'wikidiff2' && !function_exists( 'wikidiff2_do_diff' ) ) {
 682                         wfProfileIn( __METHOD__ . '-php_wikidiff2.so' );
 683                         wfSuppressWarnings();
 684                         wfDl( 'wikidiff2' );
 685                         wfRestoreWarnings();
 686                         wfProfileOut( __METHOD__ . '-php_wikidiff2.so' );
 687                 }
 688         }
 689
 690         /**
 691          * Generate a diff, no caching
 692          *
 693          * @param $otext String: old text, must be already segmented
 694          * @param $ntext String: new text, must be already segmented
 695          */
 696         function generateDiffBody( $otext, $ntext ) {
 697                 global $wgExternalDiffEngine, $wgContLang;
 698
 699                 $otext = str_replace( "\r\n", "\n", $otext );
 700                 $ntext = str_replace( "\r\n", "\n", $ntext );
 701
 702                 $this->initDiffEngines();
 703
 704                 if ( $wgExternalDiffEngine == 'wikidiff' && function_exists( 'wikidiff_do_diff' ) ) {
 705                         # For historical reasons, external diff engine expects
 706                         # input text to be HTML-escaped already
 707                         $otext = htmlspecialchars ( $wgContLang->segmentForDiff( $otext ) );
 708                         $ntext = htmlspecialchars ( $wgContLang->segmentForDiff( $ntext ) );
 709                         return $wgContLang->unsegementForDiff( wikidiff_do_diff( $otext, $ntext, 2 ) ) .
 710                         $this->debug( 'wikidiff1' );
 711                 }
 712
 713                 if ( $wgExternalDiffEngine == 'wikidiff2' && function_exists( 'wikidiff2_do_diff' ) ) {
 714                         # Better external diff engine, the 2 may some day be dropped
 715                         # This one does the escaping and segmenting itself
 716                         wfProfileIn( 'wikidiff2_do_diff' );
 717                         $text = wikidiff2_do_diff( $otext, $ntext, 2 );
 718                         $text .= $this->debug( 'wikidiff2' );
 719                         wfProfileOut( 'wikidiff2_do_diff' );
 720                         return $text;
 721                 }
 722                 if ( $wgExternalDiffEngine != 'wikidiff3' && $wgExternalDiffEngine !== false ) {
 723                         # Diff via the shell
 724                         global $wgTmpDirectory;
 725                         $tempName1 = tempnam( $wgTmpDirectory, 'diff_' );
 726                         $tempName2 = tempnam( $wgTmpDirectory, 'diff_' );
 727
 728                         $tempFile1 = fopen( $tempName1, "w" );
 729                         if ( !$tempFile1 ) {
 730                                 wfProfileOut( __METHOD__ );
 731                                 return false;
 732                         }
 733                         $tempFile2 = fopen( $tempName2, "w" );
 734                         if ( !$tempFile2 ) {
 735                                 wfProfileOut( __METHOD__ );
 736                                 return false;
 737                         }
 738                         fwrite( $tempFile1, $otext );
 739                         fwrite( $tempFile2, $ntext );
 740                         fclose( $tempFile1 );
 741                         fclose( $tempFile2 );
 742                         $cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
 743                         wfProfileIn( __METHOD__ . "-shellexec" );
 744                         $difftext = wfShellExec( $cmd );
 745                         $difftext .= $this->debug( "external $wgExternalDiffEngine" );
 746                         wfProfileOut( __METHOD__ . "-shellexec" );
 747                         unlink( $tempName1 );
 748                         unlink( $tempName2 );
 749                         return $difftext;
 750                 }
 751
 752                 # Native PHP diff
 753                 $ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) );
 754                 $nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) );
 755                 $diffs = new Diff( $ota, $nta );
 756                 $formatter = new TableDiffFormatter();
 757                 return $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) ) .
 758                 $this->debug();
 759         }
 760
 761         /**
 762          * Generate a debug comment indicating diff generating time,
 763          * server node, and generator backend.
 764          */
 765         protected function debug( $generator="internal" ) {
 766                 global $wgShowHostnames;
 767                 if ( !$this->enableDebugComment ) {
 768                         return '';
 769                 }
 770                 $data = array( $generator );
 771                 if( $wgShowHostnames ) {
 772                         $data[] = wfHostname();
 773                 }
 774                 $data[] = wfTimestamp( TS_DB );
 775                 return "<!-- diff generator: " .
 776                 implode( " ",
 777                 array_map(
 778                                         "htmlspecialchars",
 779                 $data ) ) .
 780                         " -->\n";
 781         }
 782
 783         /**
 784          * Replace line numbers with the text in the user's language
 785          */
 786         function localiseLineNumbers( $text ) {
 787                 return preg_replace_callback( '/<!--LINE (\d+)-->/',
 788                 array( &$this, 'localiseLineNumbersCb' ), $text );
 789         }
 790
 791         function localiseLineNumbersCb( $matches ) {
 792                 global $wgLang;
 793                 if ( $matches[1] === '1' && $this->mReducedLineNumbers ) return '';
 794                 return wfMsgExt( 'lineno', 'escape', $wgLang->formatNum( $matches[1] ) );
 795         }
 796
 797
 798         /**
 799          * If there are revisions between the ones being compared, return a note saying so.
 800          */
 801         function getMultiNotice() {
 802                 if ( !is_object($this->mOldRev) || !is_object($this->mNewRev) )
 803                 return '';
 804
 805                 if( !$this->mOldPage->equals( $this->mNewPage ) ) {
 806                         // Comparing two different pages? Count would be meaningless.
 807                         return '';
 808                 }
 809
 810                 $oldid = $this->mOldRev->getId();
 811                 $newid = $this->mNewRev->getId();
 812                 if ( $oldid > $newid ) {
 813                         $tmp = $oldid; $oldid = $newid; $newid = $tmp;
 814                 }
 815
 816                 $n = $this->mTitle->countRevisionsBetween( $oldid, $newid );
 817                 if ( !$n ) {
 818                         return '';
 819                 } else {
 820                         global $wgLang;
 821                         $dbr = wfGetDB( DB_SLAVE );
 822
 823                         // Actually, the limit is $limit + 1. We do this so we can detect
 824                         // if there are > 100 authors in a given revision range. If they
 825                         // are, $limit will be passed to diff-multi-manyusers for l10n.
 826                         $limit = 100;
 827                         $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
 828                                 array(
 829                                         'rev_page = ' . $this->mOldRev->getPage(),
 830                                         'rev_id > ' . $this->mOldRev->getId(),
 831                                         'rev_id < ' . $this->mNewRev->getId()
 832                                 ), __METHOD__,
 833                                 array( 'LIMIT' => $limit + 1 )
 834                         );
 835                         $numUsers = $dbr->numRows( $res );
 836                         if( $numUsers > $limit ) {
 837                                 $msg = 'diff-multi-manyusers';
 838                                 $numUsers = $limit;
 839                         } else {
 840                                 $msg = 'diff-multi';
 841                         }
 842                         return wfMsgExt( $msg, array( 'parseinline' ), $wgLang->formatnum( $n ),
 843                                 $wgLang->formatnum( $numUsers ) );
 844                 }
 845         }
 846
 847
 848         /**
 849          * Add the header to a diff body
 850          */
 851         static function addHeader( $diff, $otitle, $ntitle, $multi = '', $notice = '' ) {
 852                 $header = "<table class='diff'>";
 853                 if( $diff ) { // Safari/Chrome show broken output if cols not used
 854                         $header .= "
 855                         <col class='diff-marker' />
 856                         <col class='diff-content' />
 857                         <col class='diff-marker' />
 858                         <col class='diff-content' />";
 859                         $colspan = 2;
 860                         $multiColspan = 4;
 861                 } else {
 862                         $colspan = 1;
 863                         $multiColspan = 2;
 864                 }
 865                 $header .= "
 866                 <tr valign='top'>
 867                 <td colspan='$colspan' class='diff-otitle'>{$otitle}</td>
 868                 <td colspan='$colspan' class='diff-ntitle'>{$ntitle}</td>
 869                 </tr>";
 870
 871                 if ( $multi != '' ) {
 872                         $header .= "<tr><td colspan='{$multiColspan}' align='center' class='diff-multi'>{$multi}</td></tr>";
 873                 }
 874                 if ( $notice != '' ) {
 875                         $header .= "<tr><td colspan='{$multiColspan}' align='center'>{$notice}</td></tr>";
 876                 }
 877
 878                 return $header . $diff . "</table>";
 879         }
 880
 881         /**
 882          * Use specified text instead of loading from the database
 883          */
 884         function setText( $oldText, $newText ) {
 885                 $this->mOldtext = $oldText;
 886                 $this->mNewtext = $newText;
 887                 $this->mTextLoaded = 2;
 888                 $this->mRevisionsLoaded = true;
 889         }
 890
 891         /**
 892          * Load revision metadata for the specified articles. If newid is 0, then compare
 893          * the old article in oldid to the current article; if oldid is 0, then
 894          * compare the current article to the immediately previous one (ignoring the
 895          * value of newid).
 896          *
 897          * If oldid is false, leave the corresponding revision object set
 898          * to false. This is impossible via ordinary user input, and is provided for
 899          * API convenience.
 900          */
 901         function loadRevisionData() {
 902                 global $wgLang, $wgUser;
 903                 if ( $this->mRevisionsLoaded ) {
 904                         return true;
 905                 } else {
 906                         // Whether it succeeds or fails, we don't want to try again
 907                         $this->mRevisionsLoaded = true;
 908                 }
 909
 910                 // Load the new revision object
 911                 $this->mNewRev = $this->mNewid
 912                         ? Revision::newFromId( $this->mNewid )
 913                         : Revision::newFromTitle( $this->mTitle );
 914                 if( !$this->mNewRev instanceof Revision )
 915                         return false;
 916
 917                 // Update the new revision ID in case it was 0 (makes life easier doing UI stuff)
 918                 $this->mNewid = $this->mNewRev->getId();
 919
 920                 // Check if page is editable
 921                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
 922
 923                 // Set assorted variables
 924                 $timestamp = $wgLang->timeanddate( $this->mNewRev->getTimestamp(), true );
 925                 $dateofrev = $wgLang->date( $this->mNewRev->getTimestamp(), true );
 926                 $timeofrev = $wgLang->time( $this->mNewRev->getTimestamp(), true );
 927                 $this->mNewPage = $this->mNewRev->getTitle();
 928                 if( $this->mNewRev->isCurrent() ) {
 929                         $newLink = $this->mNewPage->escapeLocalUrl( array(
 930                                 'oldid' => $this->mNewid
 931                         ) );
 932                         $this->mPagetitle = htmlspecialchars( wfMsg(
 933                                 'currentrev-asof',
 934                                 $timestamp,
 935                                 $dateofrev,
 936                                 $timeofrev
 937                         ) );
 938                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
 939                                 'action' => 'edit'
 940                         ) );
 941
 942                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
 943                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
 944                 } else {
 945                         $newLink = $this->mNewPage->escapeLocalUrl( array(
 946                                 'oldid' => $this->mNewid
 947                         ) );
 948                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
 949                                 'action' => 'edit',
 950                                 'oldid' => $this->mNewid
 951                         ) );
 952                         $this->mPagetitle = htmlspecialchars( wfMsg(
 953                                 'revisionasof',
 954                                 $timestamp,
 955                                 $dateofrev,
 956                                 $timeofrev
 957                         ) );
 958
 959                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
 960                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
 961                 }
 962                 if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
 963                         $this->mNewtitle = "<span class='history-deleted'>{$this->mPagetitle}</span>";
 964                 } else if ( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
 965                         $this->mNewtitle = "<span class='history-deleted'>{$this->mNewtitle}</span>";
 966                 }
 967
 968                 // Load the old revision object
 969                 $this->mOldRev = false;
 970                 if( $this->mOldid ) {
 971                         $this->mOldRev = Revision::newFromId( $this->mOldid );
 972                 } elseif ( $this->mOldid === 0 ) {
 973                         $rev = $this->mNewRev->getPrevious();
 974                         if( $rev ) {
 975                                 $this->mOldid = $rev->getId();
 976                                 $this->mOldRev = $rev;
 977                         } else {
 978                                 // No previous revision; mark to show as first-version only.
 979                                 $this->mOldid = false;
 980                                 $this->mOldRev = false;
 981                         }
 982                 }/* elseif ( $this->mOldid === false ) leave mOldRev false; */
 983
 984                 if( is_null( $this->mOldRev ) ) {
 985                         return false;
 986                 }
 987
 988                 if ( $this->mOldRev ) {
 989                         $this->mOldPage = $this->mOldRev->getTitle();
 990
 991                         $t = $wgLang->timeanddate( $this->mOldRev->getTimestamp(), true );
 992                         $dateofrev = $wgLang->date( $this->mOldRev->getTimestamp(), true );
 993                         $timeofrev = $wgLang->time( $this->mOldRev->getTimestamp(), true );
 994                         $oldLink = $this->mOldPage->escapeLocalUrl( array(
 995                                 'oldid' => $this->mOldid
 996                         ) );
 997                         $oldEdit = $this->mOldPage->escapeLocalUrl( array(
 998                                 'action' => 'edit',
 999                                 'oldid' => $this->mOldid
1000                         ) );
1001                         $this->mOldPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $t, $dateofrev, $timeofrev ) );
1002
1003                         $this->mOldtitle = "<a href='$oldLink'>{$this->mOldPagetitle}</a>"
1004                         . " (<a href='$oldEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1005                         // Add an "undo" link
1006                         $newUndo = $this->mNewPage->escapeLocalUrl( array(
1007                                 'action' => 'edit',
1008                                 'undoafter' => $this->mOldid,
1009                                 'undo' => $this->mNewid
1010                         ) );
1011                         $htmlLink = htmlspecialchars( wfMsg( 'editundo' ) );
1012                         $htmlTitle = $wgUser->getSkin()->tooltip( 'undo' );
1013                         if( $editable && !$this->mOldRev->isDeleted( Revision::DELETED_TEXT ) && !$this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
1014                                 $this->mNewtitle .= " (<a href='$newUndo' $htmlTitle>" . $htmlLink . "</a>)";
1015                         }
1016
1017                         if( !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
1018                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldPagetitle . '</span>';
1019                         } else if( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
1020                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldtitle . '</span>';
1021                         }
1022                 }
1023
1024                 return true;
1025         }
1026
1027         /**
1028          * Load the text of the revisions, as well as revision data.
1029          */
1030         function loadText() {
1031                 if ( $this->mTextLoaded == 2 ) {
1032                         return true;
1033                 } else {
1034                         // Whether it succeeds or fails, we don't want to try again
1035                         $this->mTextLoaded = 2;
1036                 }
1037
1038                 if ( !$this->loadRevisionData() ) {
1039                         return false;
1040                 }
1041                 if ( $this->mOldRev ) {
1042                         $this->mOldtext = $this->mOldRev->getText( Revision::FOR_THIS_USER );
1043                         if ( $this->mOldtext === false ) {
1044                                 return false;
1045                         }
1046                 }
1047                 if ( $this->mNewRev ) {
1048                         $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1049                         if ( $this->mNewtext === false ) {
1050                                 return false;
1051                         }
1052                 }
1053                 return true;
1054         }
1055
1056         /**
1057          * Load the text of the new revision, not the old one
1058          */
1059         function loadNewText() {
1060                 if ( $this->mTextLoaded >= 1 ) {
1061                         return true;
1062                 } else {
1063                         $this->mTextLoaded = 1;
1064                 }
1065                 if ( !$this->loadRevisionData() ) {
1066                         return false;
1067                 }
1068                 $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1069                 return true;
1070         }
1071 }