includes/diff/DifferenceInterface.php

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