includes/diff/DifferenceEngine.php

   1 <?php
   2 /**
   3  * User interface for the difference engine
   4  *
   5  * @file
   6  * @ingroup DifferenceEngine
   7  */
   8
   9 /**
  10  * Constant to indicate diff cache compatibility.
  11  * Bump this when changing the diff formatting in a way that
  12  * fixes important bugs or such to force cached diff views to
  13  * clear.
  14  */
  15 define( 'MW_DIFF_VERSION', '1.11a' );
  16
  17 /**
  18  * @todo document
  19  * @ingroup DifferenceEngine
  20  */
  21 class DifferenceEngine {
  22         /**#@+
  23          * @private
  24          */
  25         var $mOldid, $mNewid, $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 = $wgTitle; // @TODO: get rid of this
  66                 }
  67                 wfDebug( "DifferenceEngine old '$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                 # Allow frames except in certain special cases
 119                 $wgOut->allowClickjacking();
 120
 121                 # If external diffs are enabled both globally and for the user,
 122                 # we'll use the application/x-external-editor interface to call
 123                 # an external diff tool like kompare, kdiff3, etc.
 124                 if ( $wgUseExternalEditor && $wgUser->getOption( 'externaldiff' ) ) {
 125                         global $wgInputEncoding, $wgServer, $wgScript, $wgLang;
 126                         $wgOut->disable();
 127                         header ( "Content-type: application/x-external-editor; charset=" . $wgInputEncoding );
 128                         $url1 = $this->mTitle->getFullURL( array(
 129                                 'action' => 'raw',
 130                                 'oldid' => $this->mOldid
 131                         ) );
 132                         $url2 = $this->mTitle->getFullURL( array(
 133                                 'action' => 'raw',
 134                                 'oldid' => $this->mNewid
 135                         ) );
 136                         $special = $wgLang->getNsText( NS_SPECIAL );
 137                         $control = <<<CONTROL
 138                         [Process]
 139                         Type=Diff text
 140                         Engine=MediaWiki
 141                         Script={$wgServer}{$wgScript}
 142                         Special namespace={$special}
 143
 144                         [File]
 145                         Extension=wiki
 146                         URL=$url1
 147
 148                         [File 2]
 149                         Extension=wiki
 150                         URL=$url2
 151 CONTROL;
 152                         echo( $control );
 153                         return;
 154                 }
 155
 156                 $wgOut->setArticleFlag( false );
 157                 if ( !$this->loadRevisionData() ) {
 158                         $t = $this->mTitle->getPrefixedText();
 159                         $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
 160                         $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
 161                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", $d );
 162                         wfProfileOut( __METHOD__ );
 163                         return;
 164                 }
 165
 166                 wfRunHooks( 'DiffViewHeader', array( $this, $this->mOldRev, $this->mNewRev ) );
 167
 168                 if ( $this->mNewRev->isCurrent() ) {
 169                         $wgOut->setArticleFlag( true );
 170                 }
 171
 172                 # mOldid is false if the difference engine is called with a "vague" query for
 173                 # a diff between a version V and its previous version V' AND the version V
 174                 # is the first version of that article. In that case, V' does not exist.
 175                 if ( $this->mOldid === false ) {
 176                         $this->showFirstRevision();
 177                         $this->renderNewRevision();  // should we respect $diffOnly here or not?
 178                         wfProfileOut( __METHOD__ );
 179                         return;
 180                 }
 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                 if ( method_exists( $sk, 'suppressQuickbar' ) ) {
 206                         $sk->suppressQuickbar();
 207                 }
 208
 209                 // Check if page is editable
 210                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
 211                 if ( $editable && $this->mNewRev->isCurrent() && $wgUser->isAllowed( 'rollback' ) ) {
 212                         $wgOut->preventClickjacking();
 213                         $rollback = '&#160;&#160;&#160;' . $sk->generateRollback( $this->mNewRev );
 214                 } else {
 215                         $rollback = '';
 216                 }
 217
 218                 // Prepare a change patrol link, if applicable
 219                 if ( $wgUseRCPatrol && $this->mTitle->userCan( 'patrol' ) ) {
 220                         // If we've been given an explicit change identifier, use it; saves time
 221                         if ( $this->mRcidMarkPatrolled ) {
 222                                 $rcid = $this->mRcidMarkPatrolled;
 223                                 $rc = RecentChange::newFromId( $rcid );
 224                                 // Already patrolled?
 225                                 $rcid = is_object( $rc ) && !$rc->getAttribute( 'rc_patrolled' ) ? $rcid : 0;
 226                         } else {
 227                                 // Look for an unpatrolled change corresponding to this diff
 228                                 $db = wfGetDB( DB_SLAVE );
 229                                 $change = RecentChange::newFromConds(
 230                                         array(
 231                                         // Redundant user,timestamp condition so we can use the existing index
 232                                                 'rc_user_text'  => $this->mNewRev->getRawUserText(),
 233                                                 'rc_timestamp'  => $db->timestamp( $this->mNewRev->getTimestamp() ),
 234                                                 'rc_this_oldid' => $this->mNewid,
 235                                                 'rc_last_oldid' => $this->mOldid,
 236                                                 'rc_patrolled'  => 0
 237                                         ),
 238                                         __METHOD__
 239                                 );
 240                                 if ( $change instanceof RecentChange ) {
 241                                         $rcid = $change->mAttribs['rc_id'];
 242                                         $this->mRcidMarkPatrolled = $rcid;
 243                                 } else {
 244                                         // None found
 245                                         $rcid = 0;
 246                                 }
 247                         }
 248                         // Build the link
 249                         if ( $rcid ) {
 250                                 $wgOut->preventClickjacking();
 251                                 $token = $wgUser->editToken( $rcid );
 252                                 $patrol = ' <span class="patrollink">[' . $sk->link(
 253                                         $this->mTitle,
 254                                         wfMsgHtml( 'markaspatrolleddiff' ),
 255                                         array(),
 256                                         array(
 257                                                 'action' => 'markpatrolled',
 258                                                 'rcid' => $rcid,
 259                                                 'token' => $token,
 260                                         ),
 261                                         array(
 262                                                 'known',
 263                                                 'noclasses'
 264                                         )
 265                                 ) . ']</span>';
 266                         } else {
 267                                 $patrol = '';
 268                         }
 269                 } else {
 270                         $patrol = '';
 271                 }
 272
 273                 # Carry over 'diffonly' param via navigation links
 274                 if ( $diffOnly != $wgUser->getBoolOption( 'diffonly' ) ) {
 275                         $query['diffonly'] = $diffOnly;
 276                 }
 277
 278                 # Make "previous revision link"
 279                 $query['diff'] = 'prev';
 280                 $query['oldid'] = $this->mOldid;
 281                 # Cascade unhide param in links for easy deletion browsing
 282                 if ( $this->unhide ) {
 283                         $query['unhide'] = 1;
 284                 }
 285                 if ( !$this->mOldRev->getPrevious() ) {
 286                         $prevlink = '&#160;';
 287                 } else {
 288                         $prevlink = $sk->link(
 289                                 $this->mTitle,
 290                                 wfMsgHtml( 'previousdiff' ),
 291                                 array(
 292                                         'id' => 'differences-prevlink'
 293                                 ),
 294                                 $query,
 295                                 array(
 296                                         'known',
 297                                         'noclasses'
 298                                 )
 299                         );
 300                 }
 301
 302                 # Make "next revision link"
 303                 $query['diff'] = 'next';
 304                 $query['oldid'] = $this->mNewid;
 305                 # Skip next link on the top revision
 306                 if ( $this->mNewRev->isCurrent() ) {
 307                         $nextlink = '&#160;';
 308                 } else {
 309                         $nextlink = $sk->link(
 310                                 $this->mTitle,
 311                                 wfMsgHtml( 'nextdiff' ),
 312                                 array(
 313                                         'id' => 'differences-nextlink'
 314                                 ),
 315                                 $query,
 316                                 array(
 317                                         'known',
 318                                         'noclasses'
 319                                 )
 320                         );
 321                 }
 322
 323                 $oldminor = '';
 324                 $newminor = '';
 325
 326                 if ( $this->mOldRev->isMinor() ) {
 327                         $oldminor = ChangesList::flag( 'minor' );
 328                 }
 329                 if ( $this->mNewRev->isMinor() ) {
 330                         $newminor = ChangesList::flag( 'minor' );
 331                 }
 332
 333                 # Handle RevisionDelete links...
 334                 $ldel = $this->revisionDeleteLink( $this->mOldRev );
 335                 $rdel = $this->revisionDeleteLink( $this->mNewRev );
 336
 337                 $oldHeader = '<div id="mw-diff-otitle1"><strong>' . $this->mOldtitle . '</strong></div>' .
 338                         '<div id="mw-diff-otitle2">' .
 339                                 $sk->revUserTools( $this->mOldRev, !$this->unhide ) . '</div>' .
 340                         '<div id="mw-diff-otitle3">' . $oldminor .
 341                                 $sk->revComment( $this->mOldRev, !$diffOnly, !$this->unhide ) . $ldel . '</div>' .
 342                         '<div id="mw-diff-otitle4">' . $prevlink . '</div>';
 343                 $newHeader = '<div id="mw-diff-ntitle1"><strong>' . $this->mNewtitle . '</strong></div>' .
 344                         '<div id="mw-diff-ntitle2">' . $sk->revUserTools( $this->mNewRev, !$this->unhide ) .
 345                                 " $rollback</div>" .
 346                         '<div id="mw-diff-ntitle3">' . $newminor .
 347                                 $sk->revComment( $this->mNewRev, !$diffOnly, !$this->unhide ) . $rdel . '</div>' .
 348                         '<div id="mw-diff-ntitle4">' . $nextlink . $patrol . '</div>';
 349
 350                 # Check if this user can see the revisions
 351                 $allowed = $this->mOldRev->userCan( Revision::DELETED_TEXT )
 352                         && $this->mNewRev->userCan( Revision::DELETED_TEXT );
 353                 # Check if one of the revisions is deleted/suppressed
 354                 $deleted = $suppressed = false;
 355                 if ( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
 356                         $deleted = true; // old revisions text is hidden
 357                         if ( $this->mOldRev->isDeleted( Revision::DELETED_RESTRICTED ) )
 358                                 $suppressed = true; // also suppressed
 359                 }
 360                 if ( $this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
 361                         $deleted = true; // new revisions text is hidden
 362                         if ( $this->mNewRev->isDeleted( Revision::DELETED_RESTRICTED ) )
 363                                 $suppressed = true; // also suppressed
 364                 }
 365                 # If the diff cannot be shown due to a deleted revision, then output
 366                 # the diff header and links to unhide (if available)...
 367                 if ( $deleted && ( !$this->unhide || !$allowed ) ) {
 368                         $this->showDiffStyle();
 369                         $multi = $this->getMultiNotice();
 370                         $wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) );
 371                         if ( !$allowed ) {
 372                                 $msg = $suppressed ? 'rev-suppressed-no-diff' : 'rev-deleted-no-diff';
 373                                 # Give explanation for why revision is not visible
 374                                 $wgOut->wrapWikiMsg( "<div id='mw-$msg' class='mw-warning plainlinks'>\n$1\n</div>\n",
 375                                         array( $msg ) );
 376                         } else {
 377                                 # Give explanation and add a link to view the diff...
 378                                 $link = $this->mTitle->getFullUrl( array(
 379                                         'diff' => $this->mNewid,
 380                                         'oldid' => $this->mOldid,
 381                                         'unhide' => 1
 382                                 ) );
 383                                 $msg = $suppressed ? 'rev-suppressed-unhide-diff' : 'rev-deleted-unhide-diff';
 384                                 $wgOut->wrapWikiMsg( "<div id='mw-$msg' class='mw-warning plainlinks'>\n$1\n</div>\n", array( $msg, $link ) );
 385                         }
 386                 # Otherwise, output a regular diff...
 387                 } else {
 388                         # Add deletion notice if the user is viewing deleted content
 389                         $notice = '';
 390                         if ( $deleted ) {
 391                                 $msg = $suppressed ? 'rev-suppressed-diff-view' : 'rev-deleted-diff-view';
 392                                 $notice = "<div id='mw-$msg' class='mw-warning plainlinks'>\n" . wfMsgExt( $msg, 'parseinline' ) . "</div>\n";
 393                         }
 394                         $this->showDiff( $oldHeader, $newHeader, $notice );
 395                         if ( !$diffOnly ) {
 396                                 $this->renderNewRevision();
 397                         }
 398                 }
 399                 wfProfileOut( __METHOD__ );
 400         }
 401
 402         protected function revisionDeleteLink( $rev ) {
 403                 global $wgUser;
 404                 $link = '';
 405                 $canHide = $wgUser->isAllowed( 'deleterevision' );
 406                 // Show del/undel link if:
 407                 // (a) the user can delete revisions, or
 408                 // (b) the user can view deleted revision *and* this one is deleted
 409                 if ( $canHide || ( $rev->getVisibility() && $wgUser->isAllowed( 'deletedhistory' ) ) ) {
 410                         $sk = $wgUser->getSkin();
 411                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 412                                 $link = $sk->revDeleteLinkDisabled( $canHide ); // revision was hidden from sysops
 413                         } else {
 414                                 $query = array(
 415                                         'type'   => 'revision',
 416                                         'target' => $rev->mTitle->getPrefixedDbkey(),
 417                                         'ids'    => $rev->getId()
 418                                 );
 419                                 $link = $sk->revDeleteLink( $query,
 420                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ), $canHide );
 421                         }
 422                         $link = '&#160;&#160;&#160;' . $link . ' ';
 423                 }
 424                 return $link;
 425         }
 426
 427         /**
 428          * Show the new revision of the page.
 429          */
 430         function renderNewRevision() {
 431                 global $wgOut, $wgUser;
 432                 wfProfileIn( __METHOD__ );
 433                 # Add "current version as of X" title
 434                 $wgOut->addHTML( "<hr /><h2>{$this->mPagetitle}</h2>\n" );
 435                 # Page content may be handled by a hooked call instead...
 436                 if ( wfRunHooks( 'ArticleContentOnDiff', array( $this, $wgOut ) ) ) {
 437                         # Use the current version parser cache if applicable
 438                         $pCache = true;
 439                         if ( !$this->mNewRev->isCurrent() ) {
 440                                 $oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false );
 441                                 $pCache = false;
 442                         }
 443
 444                         $this->loadNewText();
 445                         $wgOut->setRevisionId( $this->mNewRev->getId() );
 446
 447                         if ( $this->mTitle->isCssJsSubpage() || $this->mTitle->isCssOrJsPage() ) {
 448                                 // Stolen from Article::view --AG 2007-10-11
 449                                 // Give hooks a chance to customise the output
 450                                 // @TODO: standardize this crap into one function
 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 ( $pCache ) {
 460                                 $article = new Article( $this->mTitle, 0 );
 461                                 $pOutput = ParserCache::singleton()->get( $article, $wgOut->parserOptions() );
 462                                 if( $pOutput ) {
 463                                         $wgOut->addParserOutput( $pOutput );
 464                                 } else {
 465                                         $article->doViewParse();
 466                                 }
 467                         } else {
 468                                 $wgOut->addWikiTextTidy( $this->mNewtext );
 469                         }
 470
 471                         if ( !$this->mNewRev->isCurrent() ) {
 472                                 $wgOut->parserOptions()->setEditSection( $oldEditSectionSetting );
 473                         }
 474                 }
 475                 # Add redundant patrol link on bottom...
 476                 if ( $this->mRcidMarkPatrolled && $this->mTitle->quickUserCan( 'patrol' ) ) {
 477                         $sk = $wgUser->getSkin();
 478                         $token = $wgUser->editToken( $this->mRcidMarkPatrolled );
 479                         $wgOut->preventClickjacking();
 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 (string/false)
 610          */
 611         public 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 false;
 618                 } elseif ( $this->mOldRev && !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
 619                         return false;
 620                 } elseif ( $this->mNewRev && !$this->mNewRev->userCan( Revision::DELETED_TEXT ) ) {
 621                         return false;
 622                 }
 623                 // Short-circuit
 624                 if ( $this->mOldRev && $this->mNewRev
 625                         && $this->mOldRev->getID() == $this->mNewRev->getID() )
 626                 {
 627                         return '';
 628                 }
 629                 // Cacheable?
 630                 $key = false;
 631                 if ( $this->mOldid && $this->mNewid ) {
 632                         $key = wfMemcKey( 'diff', 'version', MW_DIFF_VERSION,
 633                                 'oldid', $this->mOldid, 'newid', $this->mNewid );
 634                         // Try cache
 635                         if ( !$this->mRefreshCache ) {
 636                                 $difftext = $wgMemc->get( $key );
 637                                 if ( $difftext ) {
 638                                         wfIncrStats( 'diff_cache_hit' );
 639                                         $difftext = $this->localiseLineNumbers( $difftext );
 640                                         $difftext .= "\n<!-- diff cache key $key -->\n";
 641                                         wfProfileOut( __METHOD__ );
 642                                         return $difftext;
 643                                 }
 644                         } // don't try to load but save the result
 645                 }
 646                 $this->mCacheHit = false;
 647
 648                 // Loadtext is permission safe, this just clears out the diff
 649                 if ( !$this->loadText() ) {
 650                         wfProfileOut( __METHOD__ );
 651                         return false;
 652                 }
 653
 654                 $difftext = $this->generateDiffBody( $this->mOldtext, $this->mNewtext );
 655
 656                 // Save to cache for 7 days
 657                 if ( !wfRunHooks( 'AbortDiffCache', array( &$this ) ) ) {
 658                         wfIncrStats( 'diff_uncacheable' );
 659                 } elseif ( $key !== false && $difftext !== false ) {
 660                         wfIncrStats( 'diff_cache_miss' );
 661                         $wgMemc->set( $key, $difftext, 7 * 86400 );
 662                 } else {
 663                         wfIncrStats( 'diff_uncacheable' );
 664                 }
 665                 // Replace line numbers with the text in the user's language
 666                 if ( $difftext !== false ) {
 667                         $difftext = $this->localiseLineNumbers( $difftext );
 668                 }
 669                 wfProfileOut( __METHOD__ );
 670                 return $difftext;
 671         }
 672
 673         /**
 674          * Make sure the proper modules are loaded before we try to
 675          * make the diff
 676          */
 677         private function initDiffEngines() {
 678                 global $wgExternalDiffEngine;
 679                 if ( $wgExternalDiffEngine == 'wikidiff' && !function_exists( 'wikidiff_do_diff' ) ) {
 680                         wfProfileIn( __METHOD__ . '-php_wikidiff.so' );
 681                         wfSuppressWarnings();
 682                         dl( 'php_wikidiff.so' );
 683                         wfRestoreWarnings();
 684                         wfProfileOut( __METHOD__ . '-php_wikidiff.so' );
 685                 }
 686                 else if ( $wgExternalDiffEngine == 'wikidiff2' && !function_exists( 'wikidiff2_do_diff' ) ) {
 687                         wfProfileIn( __METHOD__ . '-php_wikidiff2.so' );
 688                         wfSuppressWarnings();
 689                         wfDl( 'wikidiff2' );
 690                         wfRestoreWarnings();
 691                         wfProfileOut( __METHOD__ . '-php_wikidiff2.so' );
 692                 }
 693         }
 694
 695         /**
 696          * Generate a diff, no caching
 697          *
 698          * @param $otext String: old text, must be already segmented
 699          * @param $ntext String: new text, must be already segmented
 700          */
 701         function generateDiffBody( $otext, $ntext ) {
 702                 global $wgExternalDiffEngine, $wgContLang;
 703
 704                 $otext = str_replace( "\r\n", "\n", $otext );
 705                 $ntext = str_replace( "\r\n", "\n", $ntext );
 706
 707                 $this->initDiffEngines();
 708
 709                 if ( $wgExternalDiffEngine == 'wikidiff' && function_exists( 'wikidiff_do_diff' ) ) {
 710                         # For historical reasons, external diff engine expects
 711                         # input text to be HTML-escaped already
 712                         $otext = htmlspecialchars ( $wgContLang->segmentForDiff( $otext ) );
 713                         $ntext = htmlspecialchars ( $wgContLang->segmentForDiff( $ntext ) );
 714                         return $wgContLang->unsegementForDiff( wikidiff_do_diff( $otext, $ntext, 2 ) ) .
 715                         $this->debug( 'wikidiff1' );
 716                 }
 717
 718                 if ( $wgExternalDiffEngine == 'wikidiff2' && function_exists( 'wikidiff2_do_diff' ) ) {
 719                         # Better external diff engine, the 2 may some day be dropped
 720                         # This one does the escaping and segmenting itself
 721                         wfProfileIn( 'wikidiff2_do_diff' );
 722                         $text = wikidiff2_do_diff( $otext, $ntext, 2 );
 723                         $text .= $this->debug( 'wikidiff2' );
 724                         wfProfileOut( 'wikidiff2_do_diff' );
 725                         return $text;
 726                 }
 727                 if ( $wgExternalDiffEngine != 'wikidiff3' && $wgExternalDiffEngine !== false ) {
 728                         # Diff via the shell
 729                         global $wgTmpDirectory;
 730                         $tempName1 = tempnam( $wgTmpDirectory, 'diff_' );
 731                         $tempName2 = tempnam( $wgTmpDirectory, 'diff_' );
 732
 733                         $tempFile1 = fopen( $tempName1, "w" );
 734                         if ( !$tempFile1 ) {
 735                                 wfProfileOut( __METHOD__ );
 736                                 return false;
 737                         }
 738                         $tempFile2 = fopen( $tempName2, "w" );
 739                         if ( !$tempFile2 ) {
 740                                 wfProfileOut( __METHOD__ );
 741                                 return false;
 742                         }
 743                         fwrite( $tempFile1, $otext );
 744                         fwrite( $tempFile2, $ntext );
 745                         fclose( $tempFile1 );
 746                         fclose( $tempFile2 );
 747                         $cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
 748                         wfProfileIn( __METHOD__ . "-shellexec" );
 749                         $difftext = wfShellExec( $cmd );
 750                         $difftext .= $this->debug( "external $wgExternalDiffEngine" );
 751                         wfProfileOut( __METHOD__ . "-shellexec" );
 752                         unlink( $tempName1 );
 753                         unlink( $tempName2 );
 754                         return $difftext;
 755                 }
 756
 757                 # Native PHP diff
 758                 $ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) );
 759                 $nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) );
 760                 $diffs = new Diff( $ota, $nta );
 761                 $formatter = new TableDiffFormatter();
 762                 return $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) ) .
 763                 $this->debug();
 764         }
 765
 766         /**
 767          * Generate a debug comment indicating diff generating time,
 768          * server node, and generator backend.
 769          */
 770         protected function debug( $generator = "internal" ) {
 771                 global $wgShowHostnames;
 772                 if ( !$this->enableDebugComment ) {
 773                         return '';
 774                 }
 775                 $data = array( $generator );
 776                 if ( $wgShowHostnames ) {
 777                         $data[] = wfHostname();
 778                 }
 779                 $data[] = wfTimestamp( TS_DB );
 780                 return "<!-- diff generator: " .
 781                 implode( " ",
 782                 array_map(
 783                                         "htmlspecialchars",
 784                 $data ) ) .
 785                         " -->\n";
 786         }
 787
 788         /**
 789          * Replace line numbers with the text in the user's language
 790          */
 791         function localiseLineNumbers( $text ) {
 792                 return preg_replace_callback( '/<!--LINE (\d+)-->/',
 793                 array( &$this, 'localiseLineNumbersCb' ), $text );
 794         }
 795
 796         function localiseLineNumbersCb( $matches ) {
 797                 global $wgLang;
 798                 if ( $matches[1] === '1' && $this->mReducedLineNumbers ) return '';
 799                 return wfMsgExt( 'lineno', 'escape', $wgLang->formatNum( $matches[1] ) );
 800         }
 801
 802
 803         /**
 804          * If there are revisions between the ones being compared, return a note saying so.
 805          * @return string
 806          */
 807         function getMultiNotice() {
 808                 if ( !is_object( $this->mOldRev ) || !is_object( $this->mNewRev ) ) {
 809                         return '';
 810                 } elseif ( !$this->mOldPage->equals( $this->mNewPage ) ) {
 811                         // Comparing two different pages? Count would be meaningless.
 812                         return '';
 813                 }
 814
 815                 $oldid = $this->mOldRev->getId();
 816                 $newid = $this->mNewRev->getId();
 817                 if ( $oldid > $newid ) {
 818                         $tmp = $oldid; $oldid = $newid; $newid = $tmp;
 819                 }
 820
 821                 $nEdits = $this->mTitle->countRevisionsBetween( $oldid, $newid );
 822                 if ( $nEdits > 0 ) {
 823                         $limit = 100;
 824                         // We use ($limit + 1) so we can detect if there are > 100 authors
 825                         // in a given revision range. In that case, diff-multi-manyusers is used.
 826                         $numUsers = $this->mTitle->countAuthorsBetween( $oldid, $newid, $limit + 1 );
 827                         return self::intermediateEditsMsg( $nEdits, $numUsers, $limit );
 828                 }
 829                 return ''; // nothing
 830         }
 831
 832         /**
 833          * Get a notice about how many intermediate edits and users there are
 834          * @param $numEdits int
 835          * @param $numUsers int
 836          * @param $limit int
 837          * @return string
 838          */
 839         public static function intermediateEditsMsg( $numEdits, $numUsers, $limit ) {
 840                 global $wgLang;
 841                 if ( $numUsers > $limit ) {
 842                         $msg = 'diff-multi-manyusers';
 843                         $numUsers = $limit;
 844                 } else {
 845                         $msg = 'diff-multi';
 846                 }
 847                 return wfMsgExt( $msg, 'parseinline',
 848                         $wgLang->formatnum( $numEdits ), $wgLang->formatnum( $numUsers ) );
 849         }
 850
 851         /**
 852          * Add the header to a diff body
 853          */
 854         static function addHeader( $diff, $otitle, $ntitle, $multi = '', $notice = '' ) {
 855                 $header = "<table class='diff'>";
 856                 if ( $diff ) { // Safari/Chrome show broken output if cols not used
 857                         $header .= "
 858                         <col class='diff-marker' />
 859                         <col class='diff-content' />
 860                         <col class='diff-marker' />
 861                         <col class='diff-content' />";
 862                         $colspan = 2;
 863                         $multiColspan = 4;
 864                 } else {
 865                         $colspan = 1;
 866                         $multiColspan = 2;
 867                 }
 868                 $header .= "
 869                 <tr valign='top'>
 870                 <td colspan='$colspan' class='diff-otitle'>{$otitle}</td>
 871                 <td colspan='$colspan' class='diff-ntitle'>{$ntitle}</td>
 872                 </tr>";
 873
 874                 if ( $multi != '' ) {
 875                         $header .= "<tr><td colspan='{$multiColspan}' align='center' class='diff-multi'>{$multi}</td></tr>";
 876                 }
 877                 if ( $notice != '' ) {
 878                         $header .= "<tr><td colspan='{$multiColspan}' align='center'>{$notice}</td></tr>";
 879                 }
 880
 881                 return $header . $diff . "</table>";
 882         }
 883
 884         /**
 885          * Use specified text instead of loading from the database
 886          */
 887         function setText( $oldText, $newText ) {
 888                 $this->mOldtext = $oldText;
 889                 $this->mNewtext = $newText;
 890                 $this->mTextLoaded = 2;
 891                 $this->mRevisionsLoaded = true;
 892         }
 893
 894         /**
 895          * Load revision metadata for the specified articles. If newid is 0, then compare
 896          * the old article in oldid to the current article; if oldid is 0, then
 897          * compare the current article to the immediately previous one (ignoring the
 898          * value of newid).
 899          *
 900          * If oldid is false, leave the corresponding revision object set
 901          * to false. This is impossible via ordinary user input, and is provided for
 902          * API convenience.
 903          */
 904         function loadRevisionData() {
 905                 global $wgLang, $wgUser;
 906                 if ( $this->mRevisionsLoaded ) {
 907                         return true;
 908                 } else {
 909                         // Whether it succeeds or fails, we don't want to try again
 910                         $this->mRevisionsLoaded = true;
 911                 }
 912
 913                 // Load the new revision object
 914                 $this->mNewRev = $this->mNewid
 915                         ? Revision::newFromId( $this->mNewid )
 916                         : Revision::newFromTitle( $this->mTitle );
 917                 if ( !$this->mNewRev instanceof Revision )
 918                         return false;
 919
 920                 // Update the new revision ID in case it was 0 (makes life easier doing UI stuff)
 921                 $this->mNewid = $this->mNewRev->getId();
 922
 923                 // Check if page is editable
 924                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
 925
 926                 // Set assorted variables
 927                 $timestamp = $wgLang->timeanddate( $this->mNewRev->getTimestamp(), true );
 928                 $dateofrev = $wgLang->date( $this->mNewRev->getTimestamp(), true );
 929                 $timeofrev = $wgLang->time( $this->mNewRev->getTimestamp(), true );
 930                 $this->mNewPage = $this->mNewRev->getTitle();
 931                 if ( $this->mNewRev->isCurrent() ) {
 932                         $newLink = $this->mNewPage->escapeLocalUrl( array(
 933                                 'oldid' => $this->mNewid
 934                         ) );
 935                         $this->mPagetitle = htmlspecialchars( wfMsg(
 936                                 'currentrev-asof',
 937                                 $timestamp,
 938                                 $dateofrev,
 939                                 $timeofrev
 940                         ) );
 941                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
 942                                 'action' => 'edit'
 943                         ) );
 944
 945                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
 946                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
 947                 } else {
 948                         $newLink = $this->mNewPage->escapeLocalUrl( array(
 949                                 'oldid' => $this->mNewid
 950                         ) );
 951                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
 952                                 'action' => 'edit',
 953                                 'oldid' => $this->mNewid
 954                         ) );
 955                         $this->mPagetitle = htmlspecialchars( wfMsg(
 956                                 'revisionasof',
 957                                 $timestamp,
 958                                 $dateofrev,
 959                                 $timeofrev
 960                         ) );
 961
 962                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
 963                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
 964                 }
 965                 if ( !$this->mNewRev->userCan( Revision::DELETED_TEXT ) ) {
 966                         $this->mNewtitle = "<span class='history-deleted'>{$this->mPagetitle}</span>";
 967                 } else if ( $this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
 968                         $this->mNewtitle = "<span class='history-deleted'>{$this->mNewtitle}</span>";
 969                 }
 970
 971                 // Load the old revision object
 972                 $this->mOldRev = false;
 973                 if ( $this->mOldid ) {
 974                         $this->mOldRev = Revision::newFromId( $this->mOldid );
 975                 } elseif ( $this->mOldid === 0 ) {
 976                         $rev = $this->mNewRev->getPrevious();
 977                         if ( $rev ) {
 978                                 $this->mOldid = $rev->getId();
 979                                 $this->mOldRev = $rev;
 980                         } else {
 981                                 // No previous revision; mark to show as first-version only.
 982                                 $this->mOldid = false;
 983                                 $this->mOldRev = false;
 984                         }
 985                 } /* elseif ( $this->mOldid === false ) leave mOldRev false; */
 986
 987                 if ( is_null( $this->mOldRev ) ) {
 988                         return false;
 989                 }
 990
 991                 if ( $this->mOldRev ) {
 992                         $this->mOldPage = $this->mOldRev->getTitle();
 993
 994                         $t = $wgLang->timeanddate( $this->mOldRev->getTimestamp(), true );
 995                         $dateofrev = $wgLang->date( $this->mOldRev->getTimestamp(), true );
 996                         $timeofrev = $wgLang->time( $this->mOldRev->getTimestamp(), true );
 997                         $oldLink = $this->mOldPage->escapeLocalUrl( array(
 998                                 'oldid' => $this->mOldid
 999                         ) );
1000                         $oldEdit = $this->mOldPage->escapeLocalUrl( array(
1001                                 'action' => 'edit',
1002                                 'oldid' => $this->mOldid
1003                         ) );
1004                         $this->mOldPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $t, $dateofrev, $timeofrev ) );
1005
1006                         $this->mOldtitle = "<a href='$oldLink'>{$this->mOldPagetitle}</a>"
1007                         . " (<a href='$oldEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1008                         // Add an "undo" link
1009                         $newUndo = $this->mNewPage->escapeLocalUrl( array(
1010                                 'action' => 'edit',
1011                                 'undoafter' => $this->mOldid,
1012                                 'undo' => $this->mNewid
1013                         ) );
1014                         $htmlLink = htmlspecialchars( wfMsg( 'editundo' ) );
1015                         $htmlTitle = Xml::expandAttributes( array( 'title' => $wgUser->getSkin()->titleAttrib( 'undo' ) ) );
1016                         if ( $editable && !$this->mOldRev->isDeleted( Revision::DELETED_TEXT ) && !$this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
1017                                 $this->mNewtitle .= " (<a href='$newUndo' $htmlTitle>" . $htmlLink . "</a>)";
1018                         }
1019
1020                         if ( !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
1021                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldPagetitle . '</span>';
1022                         } else if ( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
1023                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldtitle . '</span>';
1024                         }
1025                 }
1026
1027                 return true;
1028         }
1029
1030         /**
1031          * Load the text of the revisions, as well as revision data.
1032          */
1033         function loadText() {
1034                 if ( $this->mTextLoaded == 2 ) {
1035                         return true;
1036                 } else {
1037                         // Whether it succeeds or fails, we don't want to try again
1038                         $this->mTextLoaded = 2;
1039                 }
1040
1041                 if ( !$this->loadRevisionData() ) {
1042                         return false;
1043                 }
1044                 if ( $this->mOldRev ) {
1045                         $this->mOldtext = $this->mOldRev->getText( Revision::FOR_THIS_USER );
1046                         if ( $this->mOldtext === false ) {
1047                                 return false;
1048                         }
1049                 }
1050                 if ( $this->mNewRev ) {
1051                         $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1052                         if ( $this->mNewtext === false ) {
1053                                 return false;
1054                         }
1055                 }
1056                 return true;
1057         }
1058
1059         /**
1060          * Load the text of the new revision, not the old one
1061          */
1062         function loadNewText() {
1063                 if ( $this->mTextLoaded >= 1 ) {
1064                         return true;
1065                 } else {
1066                         $this->mTextLoaded = 1;
1067                 }
1068                 if ( !$this->loadRevisionData() ) {
1069                         return false;
1070                 }
1071                 $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1072                 return true;
1073         }
1074 }