includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Represents a title within MediaWiki.
  25  * Optionally may contain an interwiki designation or namespace.
  26  * @note This class can fetch various kinds of data from the database;
  27  *       however, it does so inefficiently.
  28  *
  29  * @internal documentation reviewed 15 Mar 2010
  30  */
  31 class Title {
  32         /** @name Static cache variables */
  33         // @{
  34         static private $titleCache = array();
  35         // @}
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  58         var $mUrlform = '';               // /< URL-encoded form of the main part
  59         var $mDbkeyform = '';             // /< Main part with underscores
  60         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  61         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  62         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  63         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  64         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  65         var $mLatestID = false;           // /< ID of most recent revision
  66         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  67         var $mOldRestrictions = false;
  68         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  69         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  70         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  71         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  72         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  73         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  74         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  75         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  76         # Don't change the following default, NS_MAIN is hardcoded in several
  77         # places.  See bug 696.
  78         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  79                                                                           # Zero except in {{transclusion}} tags
  80         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  81         var $mLength = -1;                // /< The page length, 0 for special pages
  82         var $mRedirect = null;            // /< Is the article at this title a redirect?
  83         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  84         var $mBacklinkCache = null;       // /< Cache of links to this title
  85         // @}
  86
  87
  88         /**
  89          * Constructor
  90          */
  91         /*protected*/ function __construct() { }
  92
  93         /**
  94          * Create a new Title from a prefixed DB key
  95          *
  96          * @param $key String the database key, which has underscores
  97          *      instead of spaces, possibly including namespace and
  98          *      interwiki prefixes
  99          * @return Title, or NULL on an error
 100          */
 101         public static function newFromDBkey( $key ) {
 102                 $t = new Title();
 103                 $t->mDbkeyform = $key;
 104                 if ( $t->secureAndSplit() ) {
 105                         return $t;
 106                 } else {
 107                         return null;
 108                 }
 109         }
 110
 111         /**
 112          * Create a new Title from text, such as what one would find in a link. De-
 113          * codes any HTML entities in the text.
 114          *
 115          * @param $text String the link text; spaces, prefixes, and an
 116          *   initial ':' indicating the main namespace are accepted.
 117          * @param $defaultNamespace Int the namespace to use if none is speci-
 118          *   fied by a prefix.  If you want to force a specific namespace even if
 119          *   $text might begin with a namespace prefix, use makeTitle() or
 120          *   makeTitleSafe().
 121          * @return Title, or null on an error.
 122          */
 123         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 124                 if ( is_object( $text ) ) {
 125                         throw new MWException( 'Title::newFromText given an object' );
 126                 }
 127
 128                 /**
 129                  * Wiki pages often contain multiple links to the same page.
 130                  * Title normalization and parsing can become expensive on
 131                  * pages with many links, so we can save a little time by
 132                  * caching them.
 133                  *
 134                  * In theory these are value objects and won't get changed...
 135                  */
 136                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 137                         return Title::$titleCache[$text];
 138                 }
 139
 140                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 141                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 142
 143                 $t = new Title();
 144                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 145                 $t->mDefaultNamespace = $defaultNamespace;
 146
 147                 static $cachedcount = 0 ;
 148                 if ( $t->secureAndSplit() ) {
 149                         if ( $defaultNamespace == NS_MAIN ) {
 150                                 if ( $cachedcount >= self::CACHE_MAX ) {
 151                                         # Avoid memory leaks on mass operations...
 152                                         Title::$titleCache = array();
 153                                         $cachedcount = 0;
 154                                 }
 155                                 $cachedcount++;
 156                                 Title::$titleCache[$text] =& $t;
 157                         }
 158                         return $t;
 159                 } else {
 160                         $ret = null;
 161                         return $ret;
 162                 }
 163         }
 164
 165         /**
 166          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 167          *
 168          * Example of wrong and broken code:
 169          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 170          *
 171          * Example of right code:
 172          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 173          *
 174          * Create a new Title from URL-encoded text. Ensures that
 175          * the given title's length does not exceed the maximum.
 176          *
 177          * @param $url String the title, as might be taken from a URL
 178          * @return Title the new object, or NULL on an error
 179          */
 180         public static function newFromURL( $url ) {
 181                 global $wgLegalTitleChars;
 182                 $t = new Title();
 183
 184                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 185                 # but some URLs used it as a space replacement and they still come
 186                 # from some external search tools.
 187                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 188                         $url = str_replace( '+', ' ', $url );
 189                 }
 190
 191                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 192                 if ( $t->secureAndSplit() ) {
 193                         return $t;
 194                 } else {
 195                         return null;
 196                 }
 197         }
 198
 199         /**
 200          * Create a new Title from an article ID
 201          *
 202          * @param $id Int the page_id corresponding to the Title to create
 203          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 204          * @return Title the new object, or NULL on an error
 205          */
 206         public static function newFromID( $id, $flags = 0 ) {
 207                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 208                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 209                 if ( $row !== false ) {
 210                         $title = Title::newFromRow( $row );
 211                 } else {
 212                         $title = null;
 213                 }
 214                 return $title;
 215         }
 216
 217         /**
 218          * Make an array of titles from an array of IDs
 219          *
 220          * @param $ids Array of Int Array of IDs
 221          * @return Array of Titles
 222          */
 223         public static function newFromIDs( $ids ) {
 224                 if ( !count( $ids ) ) {
 225                         return array();
 226                 }
 227                 $dbr = wfGetDB( DB_SLAVE );
 228
 229                 $res = $dbr->select(
 230                         'page',
 231                         array(
 232                                 'page_namespace', 'page_title', 'page_id',
 233                                 'page_len', 'page_is_redirect', 'page_latest',
 234                         ),
 235                         array( 'page_id' => $ids ),
 236                         __METHOD__
 237                 );
 238
 239                 $titles = array();
 240                 foreach ( $res as $row ) {
 241                         $titles[] = Title::newFromRow( $row );
 242                 }
 243                 return $titles;
 244         }
 245
 246         /**
 247          * Make a Title object from a DB row
 248          *
 249          * @param $row Object database row (needs at least page_title,page_namespace)
 250          * @return Title corresponding Title
 251          */
 252         public static function newFromRow( $row ) {
 253                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 254                 $t->loadFromRow( $row );
 255                 return $t;
 256         }
 257
 258         /**
 259          * Load Title object fields from a DB row.
 260          * If false is given, the title will be treated as non-existing.
 261          *
 262          * @param $row Object|false database row
 263          * @return void
 264          */
 265         public function loadFromRow( $row ) {
 266                 if ( $row ) { // page found
 267                         if ( isset( $row->page_id ) )
 268                                 $this->mArticleID = (int)$row->page_id;
 269                         if ( isset( $row->page_len ) )
 270                                 $this->mLength = (int)$row->page_len;
 271                         if ( isset( $row->page_is_redirect ) )
 272                                 $this->mRedirect = (bool)$row->page_is_redirect;
 273                         if ( isset( $row->page_latest ) )
 274                                 $this->mLatestID = (int)$row->page_latest;
 275                 } else { // page not found
 276                         $this->mArticleID = 0;
 277                         $this->mLength = 0;
 278                         $this->mRedirect = false;
 279                         $this->mLatestID = 0;
 280                 }
 281         }
 282
 283         /**
 284          * Create a new Title from a namespace index and a DB key.
 285          * It's assumed that $ns and $title are *valid*, for instance when
 286          * they came directly from the database or a special page name.
 287          * For convenience, spaces are converted to underscores so that
 288          * eg user_text fields can be used directly.
 289          *
 290          * @param $ns Int the namespace of the article
 291          * @param $title String the unprefixed database key form
 292          * @param $fragment String the link fragment (after the "#")
 293          * @param $interwiki String the interwiki prefix
 294          * @return Title the new object
 295          */
 296         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 297                 $t = new Title();
 298                 $t->mInterwiki = $interwiki;
 299                 $t->mFragment = $fragment;
 300                 $t->mNamespace = $ns = intval( $ns );
 301                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 302                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 303                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 304                 $t->mTextform = str_replace( '_', ' ', $title );
 305                 return $t;
 306         }
 307
 308         /**
 309          * Create a new Title from a namespace index and a DB key.
 310          * The parameters will be checked for validity, which is a bit slower
 311          * than makeTitle() but safer for user-provided data.
 312          *
 313          * @param $ns Int the namespace of the article
 314          * @param $title String database key form
 315          * @param $fragment String the link fragment (after the "#")
 316          * @param $interwiki String interwiki prefix
 317          * @return Title the new object, or NULL on an error
 318          */
 319         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 320                 $t = new Title();
 321                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 322                 if ( $t->secureAndSplit() ) {
 323                         return $t;
 324                 } else {
 325                         return null;
 326                 }
 327         }
 328
 329         /**
 330          * Create a new Title for the Main Page
 331          *
 332          * @return Title the new object
 333          */
 334         public static function newMainPage() {
 335                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 336                 // Don't give fatal errors if the message is broken
 337                 if ( !$title ) {
 338                         $title = Title::newFromText( 'Main Page' );
 339                 }
 340                 return $title;
 341         }
 342
 343         /**
 344          * Extract a redirect destination from a string and return the
 345          * Title, or null if the text doesn't contain a valid redirect
 346          * This will only return the very next target, useful for
 347          * the redirect table and other checks that don't need full recursion
 348          *
 349          * @param $text String: Text with possible redirect
 350          * @return Title: The corresponding Title
 351          */
 352         public static function newFromRedirect( $text ) {
 353                 return self::newFromRedirectInternal( $text );
 354         }
 355
 356         /**
 357          * Extract a redirect destination from a string and return the
 358          * Title, or null if the text doesn't contain a valid redirect
 359          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 360          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 361          *
 362          * @param $text String Text with possible redirect
 363          * @return Title
 364          */
 365         public static function newFromRedirectRecurse( $text ) {
 366                 $titles = self::newFromRedirectArray( $text );
 367                 return $titles ? array_pop( $titles ) : null;
 368         }
 369
 370         /**
 371          * Extract a redirect destination from a string and return an
 372          * array of Titles, or null if the text doesn't contain a valid redirect
 373          * The last element in the array is the final destination after all redirects
 374          * have been resolved (up to $wgMaxRedirects times)
 375          *
 376          * @param $text String Text with possible redirect
 377          * @return Array of Titles, with the destination last
 378          */
 379         public static function newFromRedirectArray( $text ) {
 380                 global $wgMaxRedirects;
 381                 $title = self::newFromRedirectInternal( $text );
 382                 if ( is_null( $title ) ) {
 383                         return null;
 384                 }
 385                 // recursive check to follow double redirects
 386                 $recurse = $wgMaxRedirects;
 387                 $titles = array( $title );
 388                 while ( --$recurse > 0 ) {
 389                         if ( $title->isRedirect() ) {
 390                                 $page = WikiPage::factory( $title );
 391                                 $newtitle = $page->getRedirectTarget();
 392                         } else {
 393                                 break;
 394                         }
 395                         // Redirects to some special pages are not permitted
 396                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 397                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 398                                 $title = $newtitle;
 399                                 $titles[] = $newtitle;
 400                         } else {
 401                                 break;
 402                         }
 403                 }
 404                 return $titles;
 405         }
 406
 407         /**
 408          * Really extract the redirect destination
 409          * Do not call this function directly, use one of the newFromRedirect* functions above
 410          *
 411          * @param $text String Text with possible redirect
 412          * @return Title
 413          */
 414         protected static function newFromRedirectInternal( $text ) {
 415                 global $wgMaxRedirects;
 416                 if ( $wgMaxRedirects < 1 ) {
 417                         //redirects are disabled, so quit early
 418                         return null;
 419                 }
 420                 $redir = MagicWord::get( 'redirect' );
 421                 $text = trim( $text );
 422                 if ( $redir->matchStartAndRemove( $text ) ) {
 423                         // Extract the first link and see if it's usable
 424                         // Ensure that it really does come directly after #REDIRECT
 425                         // Some older redirects included a colon, so don't freak about that!
 426                         $m = array();
 427                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 428                                 // Strip preceding colon used to "escape" categories, etc.
 429                                 // and URL-decode links
 430                                 if ( strpos( $m[1], '%' ) !== false ) {
 431                                         // Match behavior of inline link parsing here;
 432                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 433                                 }
 434                                 $title = Title::newFromText( $m[1] );
 435                                 // If the title is a redirect to bad special pages or is invalid, return null
 436                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 437                                         return null;
 438                                 }
 439                                 return $title;
 440                         }
 441                 }
 442                 return null;
 443         }
 444
 445 # ----------------------------------------------------------------------------
 446 #       Static functions
 447 # ----------------------------------------------------------------------------
 448
 449         /**
 450          * Get the prefixed DB key associated with an ID
 451          *
 452          * @param $id Int the page_id of the article
 453          * @return Title an object representing the article, or NULL if no such article was found
 454          */
 455         public static function nameOf( $id ) {
 456                 $dbr = wfGetDB( DB_SLAVE );
 457
 458                 $s = $dbr->selectRow(
 459                         'page',
 460                         array( 'page_namespace', 'page_title' ),
 461                         array( 'page_id' => $id ),
 462                         __METHOD__
 463                 );
 464                 if ( $s === false ) {
 465                         return null;
 466                 }
 467
 468                 $n = self::makeName( $s->page_namespace, $s->page_title );
 469                 return $n;
 470         }
 471
 472         /**
 473          * Get a regex character class describing the legal characters in a link
 474          *
 475          * @return String the list of characters, not delimited
 476          */
 477         public static function legalChars() {
 478                 global $wgLegalTitleChars;
 479                 return $wgLegalTitleChars;
 480         }
 481
 482         /**
 483          * Get a string representation of a title suitable for
 484          * including in a search index
 485          *
 486          * @param $ns Int a namespace index
 487          * @param $title String text-form main part
 488          * @return String a stripped-down title string ready for the search index
 489          */
 490         public static function indexTitle( $ns, $title ) {
 491                 global $wgContLang;
 492
 493                 $lc = SearchEngine::legalSearchChars() . '&#;';
 494                 $t = $wgContLang->normalizeForSearch( $title );
 495                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 496                 $t = $wgContLang->lc( $t );
 497
 498                 # Handle 's, s'
 499                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 500                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 501
 502                 $t = preg_replace( "/\\s+/", ' ', $t );
 503
 504                 if ( $ns == NS_FILE ) {
 505                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 506                 }
 507                 return trim( $t );
 508         }
 509
 510         /**
 511          * Make a prefixed DB key from a DB key and a namespace index
 512          *
 513          * @param $ns Int numerical representation of the namespace
 514          * @param $title String the DB key form the title
 515          * @param $fragment String The link fragment (after the "#")
 516          * @param $interwiki String The interwiki prefix
 517          * @return String the prefixed form of the title
 518          */
 519         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 520                 global $wgContLang;
 521
 522                 $namespace = $wgContLang->getNsText( $ns );
 523                 $name = $namespace == '' ? $title : "$namespace:$title";
 524                 if ( strval( $interwiki ) != '' ) {
 525                         $name = "$interwiki:$name";
 526                 }
 527                 if ( strval( $fragment ) != '' ) {
 528                         $name .= '#' . $fragment;
 529                 }
 530                 return $name;
 531         }
 532
 533         /**
 534          * Determine whether the object refers to a page within
 535          * this project.
 536          *
 537          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 538          */
 539         public function isLocal() {
 540                 if ( $this->mInterwiki != '' ) {
 541                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 542                 } else {
 543                         return true;
 544                 }
 545         }
 546
 547         /**
 548          * Determine whether the object refers to a page within
 549          * this project and is transcludable.
 550          *
 551          * @return Bool TRUE if this is transcludable
 552          */
 553         public function isTrans() {
 554                 if ( $this->mInterwiki == '' ) {
 555                         return false;
 556                 }
 557
 558                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 559         }
 560
 561         /**
 562          * Returns the DB name of the distant wiki which owns the object.
 563          *
 564          * @return String the DB name
 565          */
 566         public function getTransWikiID() {
 567                 if ( $this->mInterwiki == '' ) {
 568                         return false;
 569                 }
 570
 571                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 572         }
 573
 574         /**
 575          * Escape a text fragment, say from a link, for a URL
 576          *
 577          * @param $fragment string containing a URL or link fragment (after the "#")
 578          * @return String: escaped string
 579          */
 580         static function escapeFragmentForURL( $fragment ) {
 581                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 582                 # fragments appear not to work in IE (at least up to 7) or in at least
 583                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 584                 # to care if they aren't encoded.
 585                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 586         }
 587
 588 # ----------------------------------------------------------------------------
 589 #       Other stuff
 590 # ----------------------------------------------------------------------------
 591
 592         /** Simple accessors */
 593         /**
 594          * Get the text form (spaces not underscores) of the main part
 595          *
 596          * @return String Main part of the title
 597          */
 598         public function getText() { return $this->mTextform; }
 599
 600         /**
 601          * Get the URL-encoded form of the main part
 602          *
 603          * @return String Main part of the title, URL-encoded
 604          */
 605         public function getPartialURL() { return $this->mUrlform; }
 606
 607         /**
 608          * Get the main part with underscores
 609          *
 610          * @return String: Main part of the title, with underscores
 611          */
 612         public function getDBkey() { return $this->mDbkeyform; }
 613
 614         /**
 615          * Get the namespace index, i.e. one of the NS_xxxx constants.
 616          *
 617          * @return Integer: Namespace index
 618          */
 619         public function getNamespace() { return $this->mNamespace; }
 620
 621         /**
 622          * Get the namespace text
 623          *
 624          * @return String: Namespace text
 625          */
 626         public function getNsText() {
 627                 global $wgContLang;
 628
 629                 if ( $this->mInterwiki != '' ) {
 630                         // This probably shouldn't even happen. ohh man, oh yuck.
 631                         // But for interwiki transclusion it sometimes does.
 632                         // Shit. Shit shit shit.
 633                         //
 634                         // Use the canonical namespaces if possible to try to
 635                         // resolve a foreign namespace.
 636                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 637                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 638                         }
 639                 }
 640
 641                 // Strip off subpages
 642                 $pagename = $this->getText();
 643                 if ( strpos( $pagename, '/' ) !== false ) {
 644                         list( $username , ) = explode( '/', $pagename, 2 );
 645                 } else {
 646                         $username = $pagename;
 647                 }
 648
 649                 if ( $wgContLang->needsGenderDistinction() &&
 650                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 651                         $gender = GenderCache::singleton()->getGenderOf( $username, __METHOD__ );
 652                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 653                 }
 654
 655                 return $wgContLang->getNsText( $this->mNamespace );
 656         }
 657
 658         /**
 659          * Get the DB key with the initial letter case as specified by the user
 660          *
 661          * @return String DB key
 662          */
 663         function getUserCaseDBKey() {
 664                 return $this->mUserCaseDBKey;
 665         }
 666
 667         /**
 668          * Get the namespace text of the subject (rather than talk) page
 669          *
 670          * @return String Namespace text
 671          */
 672         public function getSubjectNsText() {
 673                 global $wgContLang;
 674                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 675         }
 676
 677         /**
 678          * Get the namespace text of the talk page
 679          *
 680          * @return String Namespace text
 681          */
 682         public function getTalkNsText() {
 683                 global $wgContLang;
 684                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 685         }
 686
 687         /**
 688          * Could this title have a corresponding talk page?
 689          *
 690          * @return Bool TRUE or FALSE
 691          */
 692         public function canTalk() {
 693                 return( MWNamespace::canTalk( $this->mNamespace ) );
 694         }
 695
 696         /**
 697          * Get the interwiki prefix (or null string)
 698          *
 699          * @return String Interwiki prefix
 700          */
 701         public function getInterwiki() { return $this->mInterwiki; }
 702
 703         /**
 704          * Get the Title fragment (i.e.\ the bit after the #) in text form
 705          *
 706          * @return String Title fragment
 707          */
 708         public function getFragment() { return $this->mFragment; }
 709
 710         /**
 711          * Get the fragment in URL form, including the "#" character if there is one
 712          * @return String Fragment in URL form
 713          */
 714         public function getFragmentForURL() {
 715                 if ( $this->mFragment == '' ) {
 716                         return '';
 717                 } else {
 718                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 719                 }
 720         }
 721
 722         /**
 723          * Get the default namespace index, for when there is no namespace
 724          *
 725          * @return Int Default namespace index
 726          */
 727         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 728
 729         /**
 730          * Get title for search index
 731          *
 732          * @return String a stripped-down title string ready for the
 733          *  search index
 734          */
 735         public function getIndexTitle() {
 736                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 737         }
 738
 739         /**
 740          * Get the prefixed database key form
 741          *
 742          * @return String the prefixed title, with underscores and
 743          *  any interwiki and namespace prefixes
 744          */
 745         public function getPrefixedDBkey() {
 746                 $s = $this->prefix( $this->mDbkeyform );
 747                 $s = str_replace( ' ', '_', $s );
 748                 return $s;
 749         }
 750
 751         /**
 752          * Get the prefixed title with spaces.
 753          * This is the form usually used for display
 754          *
 755          * @return String the prefixed title, with spaces
 756          */
 757         public function getPrefixedText() {
 758                 // @todo FIXME: Bad usage of empty() ?
 759                 if ( empty( $this->mPrefixedText ) ) {
 760                         $s = $this->prefix( $this->mTextform );
 761                         $s = str_replace( '_', ' ', $s );
 762                         $this->mPrefixedText = $s;
 763                 }
 764                 return $this->mPrefixedText;
 765         }
 766
 767         /**
 768         /**
 769          * Get the prefixed title with spaces, plus any fragment
 770          * (part beginning with '#')
 771          *
 772          * @return String the prefixed title, with spaces and the fragment, including '#'
 773          */
 774         public function getFullText() {
 775                 $text = $this->getPrefixedText();
 776                 if ( $this->mFragment != '' ) {
 777                         $text .= '#' . $this->mFragment;
 778                 }
 779                 return $text;
 780         }
 781
 782         /**
 783          * Get the base page name, i.e. the leftmost part before any slashes
 784          *
 785          * @return String Base name
 786          */
 787         public function getBaseText() {
 788                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 789                         return $this->getText();
 790                 }
 791
 792                 $parts = explode( '/', $this->getText() );
 793                 # Don't discard the real title if there's no subpage involved
 794                 if ( count( $parts ) > 1 ) {
 795                         unset( $parts[count( $parts ) - 1] );
 796                 }
 797                 return implode( '/', $parts );
 798         }
 799
 800         /**
 801          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
 802          *
 803          * @return String Subpage name
 804          */
 805         public function getSubpageText() {
 806                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 807                         return( $this->mTextform );
 808                 }
 809                 $parts = explode( '/', $this->mTextform );
 810                 return( $parts[count( $parts ) - 1] );
 811         }
 812
 813         /**
 814          * Get a URL-encoded form of the subpage text
 815          *
 816          * @return String URL-encoded subpage name
 817          */
 818         public function getSubpageUrlForm() {
 819                 $text = $this->getSubpageText();
 820                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 821                 return( $text );
 822         }
 823
 824         /**
 825          * Get a URL-encoded title (not an actual URL) including interwiki
 826          *
 827          * @return String the URL-encoded form
 828          */
 829         public function getPrefixedURL() {
 830                 $s = $this->prefix( $this->mDbkeyform );
 831                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 832                 return $s;
 833         }
 834
 835         /**
 836          * Get a real URL referring to this title, with interwiki link and
 837          * fragment
 838          *
 839          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 840          *   links. Can be specified as an associative array as well, e.g.,
 841          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 842          * @param $variant String language variant of url (for sr, zh..)
 843          * @return String the URL
 844          */
 845         public function getFullURL( $query = '', $variant = false ) {
 846                 # Hand off all the decisions on urls to getLocalURL
 847                 $url = $this->getLocalURL( $query, $variant );
 848
 849                 # Expand the url to make it a full url. Note that getLocalURL has the
 850                 # potential to output full urls for a variety of reasons, so we use
 851                 # wfExpandUrl instead of simply prepending $wgServer
 852                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
 853
 854                 # Finally, add the fragment.
 855                 $url .= $this->getFragmentForURL();
 856
 857                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query, $variant ) );
 858                 return $url;
 859         }
 860
 861         /**
 862          * Get a URL with no fragment or server name.  If this page is generated
 863          * with action=render, $wgServer is prepended.
 864          *
 865          * @param $query Mixed: an optional query string; if not specified,
 866          *   $wgArticlePath will be used.  Can be specified as an associative array
 867          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 868          *   URL-escaped).
 869          * @param $variant String language variant of url (for sr, zh..)
 870          * @return String the URL
 871          */
 872         public function getLocalURL( $query = '', $variant = false ) {
 873                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 874                 global $wgVariantArticlePath;
 875
 876                 if ( is_array( $query ) ) {
 877                         $query = wfArrayToCGI( $query );
 878                 }
 879
 880                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 881                 if ( $interwiki ) {
 882                         $namespace = $this->getNsText();
 883                         if ( $namespace != '' ) {
 884                                 # Can this actually happen? Interwikis shouldn't be parsed.
 885                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 886                                 $namespace .= ':';
 887                         }
 888                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 889                         $url = wfAppendQuery( $url, $query );
 890                 } else {
 891                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 892                         if ( $query == '' ) {
 893                                 if ( $variant != false && $this->getPageLanguage()->hasVariants() ) {
 894                                         if ( !$wgVariantArticlePath ) {
 895                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 896                                         } else {
 897                                                 $variantArticlePath = $wgVariantArticlePath;
 898                                         }
 899                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 900                                         $url = str_replace( '$1', $dbkey, $url  );
 901                                 } else {
 902                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 903                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
 904                                 }
 905                         } else {
 906                                 global $wgActionPaths;
 907                                 $url = false;
 908                                 $matches = array();
 909                                 if ( !empty( $wgActionPaths ) &&
 910                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 911                                 {
 912                                         $action = urldecode( $matches[2] );
 913                                         if ( isset( $wgActionPaths[$action] ) ) {
 914                                                 $query = $matches[1];
 915                                                 if ( isset( $matches[4] ) ) {
 916                                                         $query .= $matches[4];
 917                                                 }
 918                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 919                                                 if ( $query != '' ) {
 920                                                         $url = wfAppendQuery( $url, $query );
 921                                                 }
 922                                         }
 923                                 }
 924
 925                                 if ( $url === false ) {
 926                                         if ( $query == '-' ) {
 927                                                 $query = '';
 928                                         }
 929                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 930                                 }
 931                         }
 932
 933                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
 934
 935                         // @todo FIXME: This causes breakage in various places when we
 936                         // actually expected a local URL and end up with dupe prefixes.
 937                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 938                                 $url = $wgServer . $url;
 939                         }
 940                 }
 941                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
 942                 return $url;
 943         }
 944
 945         /**
 946          * Get a URL that's the simplest URL that will be valid to link, locally,
 947          * to the current Title.  It includes the fragment, but does not include
 948          * the server unless action=render is used (or the link is external).  If
 949          * there's a fragment but the prefixed text is empty, we just return a link
 950          * to the fragment.
 951          *
 952          * The result obviously should not be URL-escaped, but does need to be
 953          * HTML-escaped if it's being output in HTML.
 954          *
 955          * @param $query Array of Strings An associative array of key => value pairs for the
 956          *   query string.  Keys and values will be escaped.
 957          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 958          *   for external links.  Default is "false" (same variant as current page,
 959          *   for anonymous users).
 960          * @return String the URL
 961          */
 962         public function getLinkURL( $query = array(), $variant = false ) {
 963                 wfProfileIn( __METHOD__ );
 964                 if ( $this->isExternal() ) {
 965                         $ret = $this->getFullURL( $query );
 966                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 967                         $ret = $this->getFragmentForURL();
 968                 } else {
 969                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 970                 }
 971                 wfProfileOut( __METHOD__ );
 972                 return $ret;
 973         }
 974
 975         /**
 976          * Get an HTML-escaped version of the URL form, suitable for
 977          * using in a link, without a server name or fragment
 978          *
 979          * @param $query String an optional query string
 980          * @return String the URL
 981          */
 982         public function escapeLocalURL( $query = '' ) {
 983                 return htmlspecialchars( $this->getLocalURL( $query ) );
 984         }
 985
 986         /**
 987          * Get an HTML-escaped version of the URL form, suitable for
 988          * using in a link, including the server name and fragment
 989          *
 990          * @param $query String an optional query string
 991          * @return String the URL
 992          */
 993         public function escapeFullURL( $query = '' ) {
 994                 return htmlspecialchars( $this->getFullURL( $query ) );
 995         }
 996
 997         /**
 998          * HTML-escaped version of getCanonicalURL()
 999          * @since 1.18
1000          */
1001         public function escapeCanonicalURL( $query = '', $variant = false ) {
1002                 return htmlspecialchars( $this->getCanonicalURL( $query, $variant ) );
1003         }
1004
1005         /**
1006          * Get the URL form for an internal link.
1007          * - Used in various Squid-related code, in case we have a different
1008          * internal hostname for the server from the exposed one.
1009          *
1010          * This uses $wgInternalServer to qualify the path, or $wgServer
1011          * if $wgInternalServer is not set. If the server variable used is
1012          * protocol-relative, the URL will be expanded to http://
1013          *
1014          * @param $query String an optional query string
1015          * @param $variant String language variant of url (for sr, zh..)
1016          * @return String the URL
1017          */
1018         public function getInternalURL( $query = '', $variant = false ) {
1019                 global $wgInternalServer, $wgServer;
1020                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1021                 $url = wfExpandUrl( $server . $this->getLocalURL( $query, $variant ), PROTO_HTTP );
1022                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query, $variant ) );
1023                 return $url;
1024         }
1025
1026         /**
1027          * Get the URL for a canonical link, for use in things like IRC and
1028          * e-mail notifications. Uses $wgCanonicalServer and the
1029          * GetCanonicalURL hook.
1030          *
1031          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1032          *
1033          * @param $query string An optional query string
1034          * @param $variant string Language variant of URL (for sr, zh, ...)
1035          * @return string The URL
1036          * @since 1.18
1037          */
1038         public function getCanonicalURL( $query = '', $variant = false ) {
1039                 $url = wfExpandUrl( $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1040                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query, $variant ) );
1041                 return $url;
1042         }
1043
1044         /**
1045          * Get the edit URL for this Title
1046          *
1047          * @return String the URL, or a null string if this is an
1048          *  interwiki link
1049          */
1050         public function getEditURL() {
1051                 if ( $this->mInterwiki != '' ) {
1052                         return '';
1053                 }
1054                 $s = $this->getLocalURL( 'action=edit' );
1055
1056                 return $s;
1057         }
1058
1059         /**
1060          * Get the HTML-escaped displayable text form.
1061          * Used for the title field in <a> tags.
1062          *
1063          * @return String the text, including any prefixes
1064          */
1065         public function getEscapedText() {
1066                 return htmlspecialchars( $this->getPrefixedText() );
1067         }
1068
1069         /**
1070          * Is this Title interwiki?
1071          *
1072          * @return Bool
1073          */
1074         public function isExternal() {
1075                 return ( $this->mInterwiki != '' );
1076         }
1077
1078         /**
1079          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1080          *
1081          * @param $action String Action to check (default: edit)
1082          * @return Bool
1083          */
1084         public function isSemiProtected( $action = 'edit' ) {
1085                 if ( $this->exists() ) {
1086                         $restrictions = $this->getRestrictions( $action );
1087                         if ( count( $restrictions ) > 0 ) {
1088                                 foreach ( $restrictions as $restriction ) {
1089                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1090                                                 return false;
1091                                         }
1092                                 }
1093                         } else {
1094                                 # Not protected
1095                                 return false;
1096                         }
1097                         return true;
1098                 } else {
1099                         # If it doesn't exist, it can't be protected
1100                         return false;
1101                 }
1102         }
1103
1104         /**
1105          * Does the title correspond to a protected article?
1106          *
1107          * @param $action String the action the page is protected from,
1108          * by default checks all actions.
1109          * @return Bool
1110          */
1111         public function isProtected( $action = '' ) {
1112                 global $wgRestrictionLevels;
1113
1114                 $restrictionTypes = $this->getRestrictionTypes();
1115
1116                 # Special pages have inherent protection
1117                 if( $this->isSpecialPage() ) {
1118                         return true;
1119                 }
1120
1121                 # Check regular protection levels
1122                 foreach ( $restrictionTypes as $type ) {
1123                         if ( $action == $type || $action == '' ) {
1124                                 $r = $this->getRestrictions( $type );
1125                                 foreach ( $wgRestrictionLevels as $level ) {
1126                                         if ( in_array( $level, $r ) && $level != '' ) {
1127                                                 return true;
1128                                         }
1129                                 }
1130                         }
1131                 }
1132
1133                 return false;
1134         }
1135
1136         /**
1137          * Determines if $user is unable to edit this page because it has been protected
1138          * by $wgNamespaceProtection.
1139          *
1140          * @param $user User object to check permissions
1141          * @return Bool
1142          */
1143         public function isNamespaceProtected( User $user ) {
1144                 global $wgNamespaceProtection;
1145
1146                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1147                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1148                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1149                                         return true;
1150                                 }
1151                         }
1152                 }
1153                 return false;
1154         }
1155
1156         /**
1157          * Is this a conversion table for the LanguageConverter?
1158          *
1159          * @return Bool
1160          */
1161         public function isConversionTable() {
1162                 if(
1163                         $this->getNamespace() == NS_MEDIAWIKI &&
1164                         strpos( $this->getText(), 'Conversiontable' ) !== false
1165                 )
1166                 {
1167                         return true;
1168                 }
1169
1170                 return false;
1171         }
1172
1173         /**
1174          * Is $wgUser watching this page?
1175          *
1176          * @return Bool
1177          */
1178         public function userIsWatching() {
1179                 global $wgUser;
1180
1181                 if ( is_null( $this->mWatched ) ) {
1182                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1183                                 $this->mWatched = false;
1184                         } else {
1185                                 $this->mWatched = $wgUser->isWatched( $this );
1186                         }
1187                 }
1188                 return $this->mWatched;
1189         }
1190
1191         /**
1192          * Can $wgUser read this page?
1193          *
1194          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1195          * @return Bool
1196          * @todo fold these checks into userCan()
1197          */
1198         public function userCanRead() {
1199                 return $this->userCan( 'read' );
1200         }
1201
1202         /**
1203          * Can $wgUser perform $action on this page?
1204          * This skips potentially expensive cascading permission checks
1205          * as well as avoids expensive error formatting
1206          *
1207          * Suitable for use for nonessential UI controls in common cases, but
1208          * _not_ for functional access control.
1209          *
1210          * May provide false positives, but should never provide a false negative.
1211          *
1212          * @param $action String action that permission needs to be checked for
1213          * @param $user User to check (since 1.19)
1214          * @return Bool
1215          */
1216         public function quickUserCan( $action, $user = null ) {
1217                 return $this->userCan( $action, $user, false );
1218         }
1219
1220         /**
1221          * Can $wgUser perform $action on this page?
1222          *
1223          * @param $action String action that permission needs to be checked for
1224          * @param $user User to check (since 1.19)
1225          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1226          * @return Bool
1227          */
1228         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1229                 if ( !$user instanceof User ) {
1230                         global $wgUser;
1231                         $user = $wgUser;
1232                 }
1233                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1234         }
1235
1236         /**
1237          * Can $user perform $action on this page?
1238          *
1239          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1240          *
1241          * @param $action String action that permission needs to be checked for
1242          * @param $user User to check
1243          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1244          *   skipping checks for cascading protections and user blocks.
1245          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1246          * @return Array of arguments to wfMsg to explain permissions problems.
1247          */
1248         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1249                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1250
1251                 // Remove the errors being ignored.
1252                 foreach ( $errors as $index => $error ) {
1253                         $error_key = is_array( $error ) ? $error[0] : $error;
1254
1255                         if ( in_array( $error_key, $ignoreErrors ) ) {
1256                                 unset( $errors[$index] );
1257                         }
1258                 }
1259
1260                 return $errors;
1261         }
1262
1263         /**
1264          * Permissions checks that fail most often, and which are easiest to test.
1265          *
1266          * @param $action String the action to check
1267          * @param $user User user to check
1268          * @param $errors Array list of current errors
1269          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1270          * @param $short Boolean short circuit on first error
1271          *
1272          * @return Array list of errors
1273          */
1274         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1275                 $ns = $this->getNamespace();
1276
1277                 if ( $action == 'create' ) {
1278                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1279                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1280                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1281                         }
1282                 } elseif ( $action == 'move' ) {
1283                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1284                                         && $ns == NS_USER && !$this->isSubpage() ) {
1285                                 // Show user page-specific message only if the user can move other pages
1286                                 $errors[] = array( 'cant-move-user-page' );
1287                         }
1288
1289                         // Check if user is allowed to move files if it's a file
1290                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1291                                 $errors[] = array( 'movenotallowedfile' );
1292                         }
1293
1294                         if ( !$user->isAllowed( 'move', $ns) ) {
1295                                 // User can't move anything
1296
1297                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1298                                         array( 'user' ), $ns ), true );
1299                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1300                                         array( 'autoconfirmed' ), $ns ), true );
1301
1302                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1303                                         // custom message if logged-in users without any special rights can move
1304                                         $errors[] = array( 'movenologintext' );
1305                                 } else {
1306                                         $errors[] = array( 'movenotallowed' );
1307                                 }
1308                         }
1309                 } elseif ( $action == 'move-target' ) {
1310                         if ( !$user->isAllowed( 'move', $ns ) ) {
1311                                 // User can't move anything
1312                                 $errors[] = array( 'movenotallowed' );
1313                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1314                                         && $ns == NS_USER && !$this->isSubpage() ) {
1315                                 // Show user page-specific message only if the user can move other pages
1316                                 $errors[] = array( 'cant-move-to-user-page' );
1317                         }
1318                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1319                         $errors[] = $this->missingPermissionError( $action, $short );
1320                 }
1321
1322                 return $errors;
1323         }
1324
1325         /**
1326          * Add the resulting error code to the errors array
1327          *
1328          * @param $errors Array list of current errors
1329          * @param $result Mixed result of errors
1330          *
1331          * @return Array list of errors
1332          */
1333         private function resultToError( $errors, $result ) {
1334                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1335                         // A single array representing an error
1336                         $errors[] = $result;
1337                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1338                         // A nested array representing multiple errors
1339                         $errors = array_merge( $errors, $result );
1340                 } elseif ( $result !== '' && is_string( $result ) ) {
1341                         // A string representing a message-id
1342                         $errors[] = array( $result );
1343                 } elseif ( $result === false ) {
1344                         // a generic "We don't want them to do that"
1345                         $errors[] = array( 'badaccess-group0' );
1346                 }
1347                 return $errors;
1348         }
1349
1350         /**
1351          * Check various permission hooks
1352          *
1353          * @param $action String the action to check
1354          * @param $user User user to check
1355          * @param $errors Array list of current errors
1356          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1357          * @param $short Boolean short circuit on first error
1358          *
1359          * @return Array list of errors
1360          */
1361         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1362                 // Use getUserPermissionsErrors instead
1363                 $result = '';
1364                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1365                         return $result ? array() : array( array( 'badaccess-group0' ) );
1366                 }
1367                 // Check getUserPermissionsErrors hook
1368                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1369                         $errors = $this->resultToError( $errors, $result );
1370                 }
1371                 // Check getUserPermissionsErrorsExpensive hook
1372                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1373                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1374                         $errors = $this->resultToError( $errors, $result );
1375                 }
1376
1377                 return $errors;
1378         }
1379
1380         /**
1381          * Check permissions on special pages & namespaces
1382          *
1383          * @param $action String the action to check
1384          * @param $user User user to check
1385          * @param $errors Array list of current errors
1386          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1387          * @param $short Boolean short circuit on first error
1388          *
1389          * @return Array list of errors
1390          */
1391         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1392                 # Only 'createaccount' and 'execute' can be performed on
1393                 # special pages, which don't actually exist in the DB.
1394                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1395                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1396                         $errors[] = array( 'ns-specialprotected' );
1397                 }
1398
1399                 # Check $wgNamespaceProtection for restricted namespaces
1400                 if ( $this->isNamespaceProtected( $user ) ) {
1401                         $ns = $this->mNamespace == NS_MAIN ?
1402                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1403                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1404                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1405                 }
1406
1407                 return $errors;
1408         }
1409
1410         /**
1411          * Check CSS/JS sub-page permissions
1412          *
1413          * @param $action String the action to check
1414          * @param $user User user to check
1415          * @param $errors Array list of current errors
1416          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1417          * @param $short Boolean short circuit on first error
1418          *
1419          * @return Array list of errors
1420          */
1421         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1422                 # Protect css/js subpages of user pages
1423                 # XXX: this might be better using restrictions
1424                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1425                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1426                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1427                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1428                                 $errors[] = array( 'customcssprotected' );
1429                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1430                                 $errors[] = array( 'customjsprotected' );
1431                         }
1432                 }
1433
1434                 return $errors;
1435         }
1436
1437         /**
1438          * Check against page_restrictions table requirements on this
1439          * page. The user must possess all required rights for this
1440          * action.
1441          *
1442          * @param $action String the action to check
1443          * @param $user User user to check
1444          * @param $errors Array list of current errors
1445          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1446          * @param $short Boolean short circuit on first error
1447          *
1448          * @return Array list of errors
1449          */
1450         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1451                 foreach ( $this->getRestrictions( $action ) as $right ) {
1452                         // Backwards compatibility, rewrite sysop -> protect
1453                         if ( $right == 'sysop' ) {
1454                                 $right = 'protect';
1455                         }
1456                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1457                                 // Users with 'editprotected' permission can edit protected pages
1458                                 // without cascading option turned on.
1459                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected', $this->mNamespace )
1460                                         || $this->mCascadeRestriction )
1461                                 {
1462                                         $errors[] = array( 'protectedpagetext', $right );
1463                                 }
1464                         }
1465                 }
1466
1467                 return $errors;
1468         }
1469
1470         /**
1471          * Check restrictions on cascading pages.
1472          *
1473          * @param $action String the action to check
1474          * @param $user User to check
1475          * @param $errors Array list of current errors
1476          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1477          * @param $short Boolean short circuit on first error
1478          *
1479          * @return Array list of errors
1480          */
1481         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1482                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1483                         # We /could/ use the protection level on the source page, but it's
1484                         # fairly ugly as we have to establish a precedence hierarchy for pages
1485                         # included by multiple cascade-protected pages. So just restrict
1486                         # it to people with 'protect' permission, as they could remove the
1487                         # protection anyway.
1488                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1489                         # Cascading protection depends on more than this page...
1490                         # Several cascading protected pages may include this page...
1491                         # Check each cascading level
1492                         # This is only for protection restrictions, not for all actions
1493                         if ( isset( $restrictions[$action] ) ) {
1494                                 foreach ( $restrictions[$action] as $right ) {
1495                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1496                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1497                                                 $pages = '';
1498                                                 foreach ( $cascadingSources as $page )
1499                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1500                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1501                                         }
1502                                 }
1503                         }
1504                 }
1505
1506                 return $errors;
1507         }
1508
1509         /**
1510          * Check action permissions not already checked in checkQuickPermissions
1511          *
1512          * @param $action String the action to check
1513          * @param $user User to check
1514          * @param $errors Array list of current errors
1515          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1516          * @param $short Boolean short circuit on first error
1517          *
1518          * @return Array list of errors
1519          */
1520         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1521                 if ( $action == 'protect' ) {
1522                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1523                                 // If they can't edit, they shouldn't protect.
1524                                 $errors[] = array( 'protect-cantedit' );
1525                         }
1526                 } elseif ( $action == 'create' ) {
1527                         $title_protection = $this->getTitleProtection();
1528                         if( $title_protection ) {
1529                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1530                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1531                                 }
1532                                 if( $title_protection['pt_create_perm'] == '' ||
1533                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1534                                                 $this->mNamespace ) ) {
1535                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1536                                 }
1537                         }
1538                 } elseif ( $action == 'move' ) {
1539                         // Check for immobile pages
1540                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1541                                 // Specific message for this case
1542                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1543                         } elseif ( !$this->isMovable() ) {
1544                                 // Less specific message for rarer cases
1545                                 $errors[] = array( 'immobile-source-page' );
1546                         }
1547                 } elseif ( $action == 'move-target' ) {
1548                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1549                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1550                         } elseif ( !$this->isMovable() ) {
1551                                 $errors[] = array( 'immobile-target-page' );
1552                         }
1553                 }
1554                 return $errors;
1555         }
1556
1557         /**
1558          * Check that the user isn't blocked from editting.
1559          *
1560          * @param $action String the action to check
1561          * @param $user User to check
1562          * @param $errors Array list of current errors
1563          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1564          * @param $short Boolean short circuit on first error
1565          *
1566          * @return Array list of errors
1567          */
1568         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1569                 // Account creation blocks handled at userlogin.
1570                 // Unblocking handled in SpecialUnblock
1571                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1572                         return $errors;
1573                 }
1574
1575                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1576
1577                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1578                         $errors[] = array( 'confirmedittext' );
1579                 }
1580
1581                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1582                         // Don't block the user from editing their own talk page unless they've been
1583                         // explicitly blocked from that too.
1584                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1585                         $block = $user->mBlock;
1586
1587                         // This is from OutputPage::blockedPage
1588                         // Copied at r23888 by werdna
1589
1590                         $id = $user->blockedBy();
1591                         $reason = $user->blockedFor();
1592                         if ( $reason == '' ) {
1593                                 $reason = wfMsg( 'blockednoreason' );
1594                         }
1595                         $ip = $user->getRequest()->getIP();
1596
1597                         if ( is_numeric( $id ) ) {
1598                                 $name = User::whoIs( $id );
1599                         } else {
1600                                 $name = $id;
1601                         }
1602
1603                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1604                         $blockid = $block->getId();
1605                         $blockExpiry = $user->mBlock->mExpiry;
1606                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1607                         if ( $blockExpiry == 'infinity' ) {
1608                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1609                         } else {
1610                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1611                         }
1612
1613                         $intended = strval( $user->mBlock->getTarget() );
1614
1615                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1616                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1617                 }
1618
1619                 return $errors;
1620         }
1621
1622         /**
1623          * Check that the user is allowed to read this page.
1624          *
1625          * @param $action String the action to check
1626          * @param $user User to check
1627          * @param $errors Array list of current errors
1628          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1629          * @param $short Boolean short circuit on first error
1630          *
1631          * @return Array list of errors
1632          */
1633         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1634                 static $useShortcut = null;
1635
1636                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1637                 if ( is_null( $useShortcut ) ) {
1638                         global $wgGroupPermissions, $wgRevokePermissions;
1639                         $useShortcut = true;
1640                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1641                                 # Not a public wiki, so no shortcut
1642                                 $useShortcut = false;
1643                         } elseif ( !empty( $wgRevokePermissions ) ) {
1644                                 /**
1645                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1646                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1647                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1648                                  * reading is allowed.
1649                                  */
1650                                 foreach ( $wgRevokePermissions as $perms ) {
1651                                         if ( !empty( $perms['read'] ) ) {
1652                                                 # We might be removing the read right from the user, so no shortcut
1653                                                 $useShortcut = false;
1654                                                 break;
1655                                         }
1656                                 }
1657                         }
1658                 }
1659
1660                 # Shortcut for public wikis, allows skipping quite a bit of code
1661                 if ( $useShortcut ) {
1662                         return $errors;
1663                 }
1664
1665                 # If the user is allowed to read pages, he is allowed to read all pages
1666                 if ( $user->isAllowed( 'read', $this->mNamespace ) ) {
1667                         return $errors;
1668                 }
1669
1670                 # Always grant access to the login page.
1671                 # Even anons need to be able to log in.
1672                 if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1673                         return $errors;
1674                 }
1675
1676                 # Time to check the whitelist
1677                 global $wgWhitelistRead;
1678
1679                 # Only to these checks is there's something to check against
1680                 if ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
1681                         # Check for explicit whitelisting
1682                         $name = $this->getPrefixedText();
1683                         $dbName = $this->getPrefixedDBKey();
1684
1685                         // Check with and without underscores
1686                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
1687                                 return $errors;
1688                         }
1689
1690                         # Old settings might have the title prefixed with
1691                         # a colon for main-namespace pages
1692                         if ( $this->getNamespace() == NS_MAIN ) {
1693                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1694                                         return $errors;
1695                                 }
1696                         }
1697
1698                         # If it's a special page, ditch the subpage bit and check again
1699                         if ( $this->isSpecialPage() ) {
1700                                 $name = $this->getDBkey();
1701                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1702                                 if ( $name !== false ) {
1703                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1704                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1705                                                 return $errors;
1706                                         }
1707                                 }
1708                         }
1709                 }
1710
1711                 $errors[] = $this->missingPermissionError( $action, $short );
1712                 return $errors;
1713         }
1714
1715         /**
1716          * Get a description array when the user doesn't have the right to perform
1717          * $action (i.e. when User::isAllowed() returns false)
1718          *
1719          * @param $action String the action to check
1720          * @param $short Boolean short circuit on first error
1721          * @return Array list of errors
1722          */
1723         private function missingPermissionError( $action, $short ) {
1724                 // We avoid expensive display logic for quickUserCan's and such
1725                 if ( $short ) {
1726                         return array( 'badaccess-group0' );
1727                 }
1728
1729                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1730                         User::getGroupsWithPermission( $action, $this->mNamespace ) );
1731
1732                 if ( count( $groups ) ) {
1733                         global $wgLang;
1734                         return array(
1735                                 'badaccess-groups',
1736                                 $wgLang->commaList( $groups ),
1737                                 count( $groups )
1738                         );
1739                 } else {
1740                         return array( 'badaccess-group0' );
1741                 }
1742         }
1743
1744         /**
1745          * Can $user perform $action on this page? This is an internal function,
1746          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1747          * checks on wfReadOnly() and blocks)
1748          *
1749          * @param $action String action that permission needs to be checked for
1750          * @param $user User to check
1751          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1752          * @param $short Bool Set this to true to stop after the first permission error.
1753          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1754          */
1755         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1756                 wfProfileIn( __METHOD__ );
1757
1758                 # Read has special handling
1759                 if ( $action == 'read' ) {
1760                         $checks = array(
1761                                 'checkPermissionHooks',
1762                                 'checkReadPermissions',
1763                         );
1764                 } else {
1765                         $checks = array(
1766                                 'checkQuickPermissions',
1767                                 'checkPermissionHooks',
1768                                 'checkSpecialsAndNSPermissions',
1769                                 'checkCSSandJSPermissions',
1770                                 'checkPageRestrictions',
1771                                 'checkCascadingSourcesRestrictions',
1772                                 'checkActionPermissions',
1773                                 'checkUserBlock'
1774                         );
1775                 }
1776
1777                 $errors = array();
1778                 while( count( $checks ) > 0 &&
1779                                 !( $short && count( $errors ) > 0 ) ) {
1780                         $method = array_shift( $checks );
1781                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1782                 }
1783
1784                 wfProfileOut( __METHOD__ );
1785                 return $errors;
1786         }
1787
1788         /**
1789          * Is this title subject to title protection?
1790          * Title protection is the one applied against creation of such title.
1791          *
1792          * @return Mixed An associative array representing any existent title
1793          *   protection, or false if there's none.
1794          */
1795         private function getTitleProtection() {
1796                 // Can't protect pages in special namespaces
1797                 if ( $this->getNamespace() < 0 ) {
1798                         return false;
1799                 }
1800
1801                 // Can't protect pages that exist.
1802                 if ( $this->exists() ) {
1803                         return false;
1804                 }
1805
1806                 if ( !isset( $this->mTitleProtection ) ) {
1807                         $dbr = wfGetDB( DB_SLAVE );
1808                         $res = $dbr->select( 'protected_titles', '*',
1809                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1810                                 __METHOD__ );
1811
1812                         // fetchRow returns false if there are no rows.
1813                         $this->mTitleProtection = $dbr->fetchRow( $res );
1814                 }
1815                 return $this->mTitleProtection;
1816         }
1817
1818         /**
1819          * Update the title protection status
1820          *
1821          * @param $create_perm String Permission required for creation
1822          * @param $reason String Reason for protection
1823          * @param $expiry String Expiry timestamp
1824          * @return boolean true
1825          */
1826         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1827                 global $wgUser, $wgContLang;
1828
1829                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1830                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1831                         // No change
1832                         return true;
1833                 }
1834
1835                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1836
1837                 $dbw = wfGetDB( DB_MASTER );
1838
1839                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1840
1841                 $expiry_description = '';
1842                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1843                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1844                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1845                 } else {
1846                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1847                 }
1848
1849                 # Update protection table
1850                 if ( $create_perm != '' ) {
1851                         $this->mTitleProtection = array(
1852                                         'pt_namespace' => $namespace,
1853                                         'pt_title' => $title,
1854                                         'pt_create_perm' => $create_perm,
1855                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1856                                         'pt_expiry' => $encodedExpiry,
1857                                         'pt_user' => $wgUser->getId(),
1858                                         'pt_reason' => $reason,
1859                                 );
1860                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1861                                 $this->mTitleProtection, __METHOD__     );
1862                 } else {
1863                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1864                                 'pt_title' => $title ), __METHOD__ );
1865                         $this->mTitleProtection = false;
1866                 }
1867
1868                 # Update the protection log
1869                 if ( $dbw->affectedRows() ) {
1870                         $log = new LogPage( 'protect' );
1871
1872                         if ( $create_perm ) {
1873                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1874                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1875                         } else {
1876                                 $log->addEntry( 'unprotect', $this, $reason );
1877                         }
1878                 }
1879
1880                 return true;
1881         }
1882
1883         /**
1884          * Remove any title protection due to page existing
1885          */
1886         public function deleteTitleProtection() {
1887                 $dbw = wfGetDB( DB_MASTER );
1888
1889                 $dbw->delete(
1890                         'protected_titles',
1891                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1892                         __METHOD__
1893                 );
1894                 $this->mTitleProtection = false;
1895         }
1896
1897         /**
1898          * Would anybody with sufficient privileges be able to move this page?
1899          * Some pages just aren't movable.
1900          *
1901          * @return Bool TRUE or FALSE
1902          */
1903         public function isMovable() {
1904                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
1905                         // Interwiki title or immovable namespace. Hooks don't get to override here
1906                         return false;
1907                 }
1908
1909                 $result = true;
1910                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1911                 return $result;
1912         }
1913
1914         /**
1915          * Is this the mainpage?
1916          * @note Title::newFromText seams to be sufficiently optimized by the title
1917          * cache that we don't need to over-optimize by doing direct comparisons and
1918          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1919          * ends up reporting something differently than $title->isMainPage();
1920          *
1921          * @since 1.18
1922          * @return Bool
1923          */
1924         public function isMainPage() {
1925                 return $this->equals( Title::newMainPage() );
1926         }
1927
1928         /**
1929          * Is this a talk page of some sort?
1930          *
1931          * @return Bool
1932          */
1933         public function isTalkPage() {
1934                 return MWNamespace::isTalk( $this->getNamespace() );
1935         }
1936
1937         /**
1938          * Is this a subpage?
1939          *
1940          * @return Bool
1941          */
1942         public function isSubpage() {
1943                 return MWNamespace::hasSubpages( $this->mNamespace )
1944                         ? strpos( $this->getText(), '/' ) !== false
1945                         : false;
1946         }
1947
1948         /**
1949          * Returns true if the title is inside the specified namespace.
1950          *
1951          * Please make use of this instead of comparing to getNamespace()
1952          * This function is much more resistant to changes we may make
1953          * to namespaces than code that makes direct comparisons.
1954          * @param $ns The namespace
1955          * @return bool
1956          * @since 1.19
1957          */
1958         public function inNamespace( $ns ) {
1959                 return MWNamespace::equals( $this->getNamespace(), $ns );
1960         }
1961
1962         /**
1963          * Returns true if the title is inside one of the specified namespaces.
1964          *
1965          * @param ...$namespaces The namespaces to check for
1966          * @return bool
1967          * @since 1.19
1968          */
1969         public function inNamespaces( /* ... */ ) {
1970                 $namespaces = func_get_args();
1971                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1972                         $namespaces = $namespaces[0];
1973                 }
1974
1975                 foreach ( $namespaces as $ns ) {
1976                         if ( $this->inNamespace( $ns ) ) {
1977                                 return true;
1978                         }
1979                 }
1980
1981                 return false;
1982         }
1983
1984         /**
1985          * Returns true if the title has the same subject namespace as the
1986          * namespace specified.
1987          * For example this method will take NS_USER and return true if namespace
1988          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1989          * as their subject namespace.
1990          *
1991          * This is MUCH simpler than individually testing for equivilance
1992          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1993          * @since 1.19
1994          */
1995         public function hasSubjectNamespace( $ns ) {
1996                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1997         }
1998
1999         /**
2000          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2001          *
2002          * @return Bool
2003          */
2004         public function hasSubpages() {
2005                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2006                         # Duh
2007                         return false;
2008                 }
2009
2010                 # We dynamically add a member variable for the purpose of this method
2011                 # alone to cache the result.  There's no point in having it hanging
2012                 # around uninitialized in every Title object; therefore we only add it
2013                 # if needed and don't declare it statically.
2014                 if ( isset( $this->mHasSubpages ) ) {
2015                         return $this->mHasSubpages;
2016                 }
2017
2018                 $subpages = $this->getSubpages( 1 );
2019                 if ( $subpages instanceof TitleArray ) {
2020                         return $this->mHasSubpages = (bool)$subpages->count();
2021                 }
2022                 return $this->mHasSubpages = false;
2023         }
2024
2025         /**
2026          * Get all subpages of this page.
2027          *
2028          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2029          * @return mixed TitleArray, or empty array if this page's namespace
2030          *  doesn't allow subpages
2031          */
2032         public function getSubpages( $limit = -1 ) {
2033                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2034                         return array();
2035                 }
2036
2037                 $dbr = wfGetDB( DB_SLAVE );
2038                 $conds['page_namespace'] = $this->getNamespace();
2039                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2040                 $options = array();
2041                 if ( $limit > -1 ) {
2042                         $options['LIMIT'] = $limit;
2043                 }
2044                 return $this->mSubpages = TitleArray::newFromResult(
2045                         $dbr->select( 'page',
2046                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2047                                 $conds,
2048                                 __METHOD__,
2049                                 $options
2050                         )
2051                 );
2052         }
2053
2054         /**
2055          * Does that page contain wikitext, or it is JS, CSS or whatever?
2056          *
2057          * @return Bool
2058          */
2059         public function isWikitextPage() {
2060                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
2061                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
2062                 return $retval;
2063         }
2064
2065         /**
2066          * Could this page contain custom CSS or JavaScript, based
2067          * on the title?
2068          *
2069          * @return Bool
2070          */
2071         public function isCssOrJsPage() {
2072                 $retval = $this->mNamespace == NS_MEDIAWIKI
2073                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
2074                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
2075                 return $retval;
2076         }
2077
2078         /**
2079          * Is this a .css or .js subpage of a user page?
2080          * @return Bool
2081          */
2082         public function isCssJsSubpage() {
2083                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
2084         }
2085
2086         /**
2087          * Is this a *valid* .css or .js subpage of a user page?
2088          *
2089          * @return Bool
2090          * @deprecated since 1.17
2091          */
2092         public function isValidCssJsSubpage() {
2093                 return $this->isCssJsSubpage();
2094         }
2095
2096         /**
2097          * Trim down a .css or .js subpage title to get the corresponding skin name
2098          *
2099          * @return string containing skin name from .css or .js subpage title
2100          */
2101         public function getSkinFromCssJsSubpage() {
2102                 $subpage = explode( '/', $this->mTextform );
2103                 $subpage = $subpage[ count( $subpage ) - 1 ];
2104                 $lastdot = strrpos( $subpage, '.' );
2105                 if ( $lastdot === false )
2106                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
2107                 return substr( $subpage, 0, $lastdot );
2108         }
2109
2110         /**
2111          * Is this a .css subpage of a user page?
2112          *
2113          * @return Bool
2114          */
2115         public function isCssSubpage() {
2116                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2117         }
2118
2119         /**
2120          * Is this a .js subpage of a user page?
2121          *
2122          * @return Bool
2123          */
2124         public function isJsSubpage() {
2125                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2126         }
2127
2128         /**
2129          * Protect css subpages of user pages: can $wgUser edit
2130          * this page?
2131          *
2132          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2133          * @return Bool
2134          */
2135         public function userCanEditCssSubpage() {
2136                 global $wgUser;
2137                 wfDeprecated( __METHOD__ );
2138                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2139                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2140         }
2141
2142         /**
2143          * Protect js subpages of user pages: can $wgUser edit
2144          * this page?
2145          *
2146          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2147          * @return Bool
2148          */
2149         public function userCanEditJsSubpage() {
2150                 global $wgUser;
2151                 wfDeprecated( __METHOD__ );
2152                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2153                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2154         }
2155
2156         /**
2157          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2158          *
2159          * @return Bool If the page is subject to cascading restrictions.
2160          */
2161         public function isCascadeProtected() {
2162                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2163                 return ( $sources > 0 );
2164         }
2165
2166         /**
2167          * Cascading protection: Get the source of any cascading restrictions on this page.
2168          *
2169          * @param $getPages Bool Whether or not to retrieve the actual pages
2170          *        that the restrictions have come from.
2171          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2172          *     have come, false for none, or true if such restrictions exist, but $getPages
2173          *     was not set.  The restriction array is an array of each type, each of which
2174          *     contains a array of unique groups.
2175          */
2176         public function getCascadeProtectionSources( $getPages = true ) {
2177                 global $wgContLang;
2178                 $pagerestrictions = array();
2179
2180                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2181                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2182                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2183                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2184                 }
2185
2186                 wfProfileIn( __METHOD__ );
2187
2188                 $dbr = wfGetDB( DB_SLAVE );
2189
2190                 if ( $this->getNamespace() == NS_FILE ) {
2191                         $tables = array( 'imagelinks', 'page_restrictions' );
2192                         $where_clauses = array(
2193                                 'il_to' => $this->getDBkey(),
2194                                 'il_from=pr_page',
2195                                 'pr_cascade' => 1
2196                         );
2197                 } else {
2198                         $tables = array( 'templatelinks', 'page_restrictions' );
2199                         $where_clauses = array(
2200                                 'tl_namespace' => $this->getNamespace(),
2201                                 'tl_title' => $this->getDBkey(),
2202                                 'tl_from=pr_page',
2203                                 'pr_cascade' => 1
2204                         );
2205                 }
2206
2207                 if ( $getPages ) {
2208                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2209                                                    'pr_expiry', 'pr_type', 'pr_level' );
2210                         $where_clauses[] = 'page_id=pr_page';
2211                         $tables[] = 'page';
2212                 } else {
2213                         $cols = array( 'pr_expiry' );
2214                 }
2215
2216                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2217
2218                 $sources = $getPages ? array() : false;
2219                 $now = wfTimestampNow();
2220                 $purgeExpired = false;
2221
2222                 foreach ( $res as $row ) {
2223                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2224                         if ( $expiry > $now ) {
2225                                 if ( $getPages ) {
2226                                         $page_id = $row->pr_page;
2227                                         $page_ns = $row->page_namespace;
2228                                         $page_title = $row->page_title;
2229                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2230                                         # Add groups needed for each restriction type if its not already there
2231                                         # Make sure this restriction type still exists
2232
2233                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2234                                                 $pagerestrictions[$row->pr_type] = array();
2235                                         }
2236
2237                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2238                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2239                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2240                                         }
2241                                 } else {
2242                                         $sources = true;
2243                                 }
2244                         } else {
2245                                 // Trigger lazy purge of expired restrictions from the db
2246                                 $purgeExpired = true;
2247                         }
2248                 }
2249                 if ( $purgeExpired ) {
2250                         Title::purgeExpiredRestrictions();
2251                 }
2252
2253                 if ( $getPages ) {
2254                         $this->mCascadeSources = $sources;
2255                         $this->mCascadingRestrictions = $pagerestrictions;
2256                 } else {
2257                         $this->mHasCascadingRestrictions = $sources;
2258                 }
2259
2260                 wfProfileOut( __METHOD__ );
2261                 return array( $sources, $pagerestrictions );
2262         }
2263
2264         /**
2265          * Returns cascading restrictions for the current article
2266          *
2267          * @return Boolean
2268          */
2269         function areRestrictionsCascading() {
2270                 if ( !$this->mRestrictionsLoaded ) {
2271                         $this->loadRestrictions();
2272                 }
2273
2274                 return $this->mCascadeRestriction;
2275         }
2276
2277         /**
2278          * Loads a string into mRestrictions array
2279          *
2280          * @param $res Resource restrictions as an SQL result.
2281          * @param $oldFashionedRestrictions String comma-separated list of page
2282          *        restrictions from page table (pre 1.10)
2283          */
2284         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2285                 $rows = array();
2286
2287                 foreach ( $res as $row ) {
2288                         $rows[] = $row;
2289                 }
2290
2291                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2292         }
2293
2294         /**
2295          * Compiles list of active page restrictions from both page table (pre 1.10)
2296          * and page_restrictions table for this existing page.
2297          * Public for usage by LiquidThreads.
2298          *
2299          * @param $rows array of db result objects
2300          * @param $oldFashionedRestrictions string comma-separated list of page
2301          *        restrictions from page table (pre 1.10)
2302          */
2303         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2304                 global $wgContLang;
2305                 $dbr = wfGetDB( DB_SLAVE );
2306
2307                 $restrictionTypes = $this->getRestrictionTypes();
2308
2309                 foreach ( $restrictionTypes as $type ) {
2310                         $this->mRestrictions[$type] = array();
2311                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2312                 }
2313
2314                 $this->mCascadeRestriction = false;
2315
2316                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2317
2318                 if ( $oldFashionedRestrictions === null ) {
2319                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2320                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2321                 }
2322
2323                 if ( $oldFashionedRestrictions != '' ) {
2324
2325                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2326                                 $temp = explode( '=', trim( $restrict ) );
2327                                 if ( count( $temp ) == 1 ) {
2328                                         // old old format should be treated as edit/move restriction
2329                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2330                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2331                                 } else {
2332                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2333                                 }
2334                         }
2335
2336                         $this->mOldRestrictions = true;
2337
2338                 }
2339
2340                 if ( count( $rows ) ) {
2341                         # Current system - load second to make them override.
2342                         $now = wfTimestampNow();
2343                         $purgeExpired = false;
2344
2345                         # Cycle through all the restrictions.
2346                         foreach ( $rows as $row ) {
2347
2348                                 // Don't take care of restrictions types that aren't allowed
2349                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2350                                         continue;
2351
2352                                 // This code should be refactored, now that it's being used more generally,
2353                                 // But I don't really see any harm in leaving it in Block for now -werdna
2354                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2355
2356                                 // Only apply the restrictions if they haven't expired!
2357                                 if ( !$expiry || $expiry > $now ) {
2358                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2359                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2360
2361                                         $this->mCascadeRestriction |= $row->pr_cascade;
2362                                 } else {
2363                                         // Trigger a lazy purge of expired restrictions
2364                                         $purgeExpired = true;
2365                                 }
2366                         }
2367
2368                         if ( $purgeExpired ) {
2369                                 Title::purgeExpiredRestrictions();
2370                         }
2371                 }
2372
2373                 $this->mRestrictionsLoaded = true;
2374         }
2375
2376         /**
2377          * Load restrictions from the page_restrictions table
2378          *
2379          * @param $oldFashionedRestrictions String comma-separated list of page
2380          *        restrictions from page table (pre 1.10)
2381          */
2382         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2383                 global $wgContLang;
2384                 if ( !$this->mRestrictionsLoaded ) {
2385                         if ( $this->exists() ) {
2386                                 $dbr = wfGetDB( DB_SLAVE );
2387
2388                                 $res = $dbr->select(
2389                                         'page_restrictions',
2390                                         '*',
2391                                         array( 'pr_page' => $this->getArticleId() ),
2392                                         __METHOD__
2393                                 );
2394
2395                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2396                         } else {
2397                                 $title_protection = $this->getTitleProtection();
2398
2399                                 if ( $title_protection ) {
2400                                         $now = wfTimestampNow();
2401                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2402
2403                                         if ( !$expiry || $expiry > $now ) {
2404                                                 // Apply the restrictions
2405                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2406                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2407                                         } else { // Get rid of the old restrictions
2408                                                 Title::purgeExpiredRestrictions();
2409                                                 $this->mTitleProtection = false;
2410                                         }
2411                                 } else {
2412                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2413                                 }
2414                                 $this->mRestrictionsLoaded = true;
2415                         }
2416                 }
2417         }
2418
2419         /**
2420          * Purge expired restrictions from the page_restrictions table
2421          */
2422         static function purgeExpiredRestrictions() {
2423                 $dbw = wfGetDB( DB_MASTER );
2424                 $dbw->delete(
2425                         'page_restrictions',
2426                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2427                         __METHOD__
2428                 );
2429
2430                 $dbw->delete(
2431                         'protected_titles',
2432                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2433                         __METHOD__
2434                 );
2435         }
2436
2437         /**
2438          * Accessor/initialisation for mRestrictions
2439          *
2440          * @param $action String action that permission needs to be checked for
2441          * @return Array of Strings the array of groups allowed to edit this article
2442          */
2443         public function getRestrictions( $action ) {
2444                 if ( !$this->mRestrictionsLoaded ) {
2445                         $this->loadRestrictions();
2446                 }
2447                 return isset( $this->mRestrictions[$action] )
2448                                 ? $this->mRestrictions[$action]
2449                                 : array();
2450         }
2451
2452         /**
2453          * Get the expiry time for the restriction against a given action
2454          *
2455          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2456          *      or not protected at all, or false if the action is not recognised.
2457          */
2458         public function getRestrictionExpiry( $action ) {
2459                 if ( !$this->mRestrictionsLoaded ) {
2460                         $this->loadRestrictions();
2461                 }
2462                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2463         }
2464
2465         /**
2466          * Is there a version of this page in the deletion archive?
2467          *
2468          * @return Int the number of archived revisions
2469          */
2470         public function isDeleted() {
2471                 if ( $this->getNamespace() < 0 ) {
2472                         $n = 0;
2473                 } else {
2474                         $dbr = wfGetDB( DB_SLAVE );
2475
2476                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2477                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2478                                 __METHOD__
2479                         );
2480                         if ( $this->getNamespace() == NS_FILE ) {
2481                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2482                                         array( 'fa_name' => $this->getDBkey() ),
2483                                         __METHOD__
2484                                 );
2485                         }
2486                 }
2487                 return (int)$n;
2488         }
2489
2490         /**
2491          * Is there a version of this page in the deletion archive?
2492          *
2493          * @return Boolean
2494          */
2495         public function isDeletedQuick() {
2496                 if ( $this->getNamespace() < 0 ) {
2497                         return false;
2498                 }
2499                 $dbr = wfGetDB( DB_SLAVE );
2500                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2501                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2502                         __METHOD__
2503                 );
2504                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2505                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2506                                 array( 'fa_name' => $this->getDBkey() ),
2507                                 __METHOD__
2508                         );
2509                 }
2510                 return $deleted;
2511         }
2512
2513         /**
2514          * Get the article ID for this Title from the link cache,
2515          * adding it if necessary
2516          *
2517          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2518          *  for update
2519          * @return Int the ID
2520          */
2521         public function getArticleID( $flags = 0 ) {
2522                 if ( $this->getNamespace() < 0 ) {
2523                         return $this->mArticleID = 0;
2524                 }
2525                 $linkCache = LinkCache::singleton();
2526                 if ( $flags & self::GAID_FOR_UPDATE ) {
2527                         $oldUpdate = $linkCache->forUpdate( true );
2528                         $linkCache->clearLink( $this );
2529                         $this->mArticleID = $linkCache->addLinkObj( $this );
2530                         $linkCache->forUpdate( $oldUpdate );
2531                 } else {
2532                         if ( -1 == $this->mArticleID ) {
2533                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2534                         }
2535                 }
2536                 return $this->mArticleID;
2537         }
2538
2539         /**
2540          * Is this an article that is a redirect page?
2541          * Uses link cache, adding it if necessary
2542          *
2543          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2544          * @return Bool
2545          */
2546         public function isRedirect( $flags = 0 ) {
2547                 if ( !is_null( $this->mRedirect ) ) {
2548                         return $this->mRedirect;
2549                 }
2550                 # Calling getArticleID() loads the field from cache as needed
2551                 if ( !$this->getArticleID( $flags ) ) {
2552                         return $this->mRedirect = false;
2553                 }
2554                 $linkCache = LinkCache::singleton();
2555                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2556
2557                 return $this->mRedirect;
2558         }
2559
2560         /**
2561          * What is the length of this page?
2562          * Uses link cache, adding it if necessary
2563          *
2564          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2565          * @return Int
2566          */
2567         public function getLength( $flags = 0 ) {
2568                 if ( $this->mLength != -1 ) {
2569                         return $this->mLength;
2570                 }
2571                 # Calling getArticleID() loads the field from cache as needed
2572                 if ( !$this->getArticleID( $flags ) ) {
2573                         return $this->mLength = 0;
2574                 }
2575                 $linkCache = LinkCache::singleton();
2576                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2577
2578                 return $this->mLength;
2579         }
2580
2581         /**
2582          * What is the page_latest field for this page?
2583          *
2584          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2585          * @return Int or 0 if the page doesn't exist
2586          */
2587         public function getLatestRevID( $flags = 0 ) {
2588                 if ( $this->mLatestID !== false ) {
2589                         return intval( $this->mLatestID );
2590                 }
2591                 # Calling getArticleID() loads the field from cache as needed
2592                 if ( !$this->getArticleID( $flags ) ) {
2593                         return $this->mLatestID = 0;
2594                 }
2595                 $linkCache = LinkCache::singleton();
2596                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2597
2598                 return $this->mLatestID;
2599         }
2600
2601         /**
2602          * This clears some fields in this object, and clears any associated
2603          * keys in the "bad links" section of the link cache.
2604          *
2605          * - This is called from Article::doEdit() and Article::insertOn() to allow
2606          * loading of the new page_id. It's also called from
2607          * Article::doDeleteArticle()
2608          *
2609          * @param $newid Int the new Article ID
2610          */
2611         public function resetArticleID( $newid ) {
2612                 $linkCache = LinkCache::singleton();
2613                 $linkCache->clearLink( $this );
2614
2615                 if ( $newid === false ) {
2616                         $this->mArticleID = -1;
2617                 } else {
2618                         $this->mArticleID = intval( $newid );
2619                 }
2620                 $this->mRestrictionsLoaded = false;
2621                 $this->mRestrictions = array();
2622                 $this->mRedirect = null;
2623                 $this->mLength = -1;
2624                 $this->mLatestID = false;
2625         }
2626
2627         /**
2628          * Updates page_touched for this page; called from LinksUpdate.php
2629          *
2630          * @return Bool true if the update succeded
2631          */
2632         public function invalidateCache() {
2633                 if ( wfReadOnly() ) {
2634                         return false;
2635                 }
2636                 $dbw = wfGetDB( DB_MASTER );
2637                 $success = $dbw->update(
2638                         'page',
2639                         array( 'page_touched' => $dbw->timestamp() ),
2640                         $this->pageCond(),
2641                         __METHOD__
2642                 );
2643                 HTMLFileCache::clearFileCache( $this );
2644                 return $success;
2645         }
2646
2647         /**
2648          * Prefix some arbitrary text with the namespace or interwiki prefix
2649          * of this object
2650          *
2651          * @param $name String the text
2652          * @return String the prefixed text
2653          * @private
2654          */
2655         private function prefix( $name ) {
2656                 $p = '';
2657                 if ( $this->mInterwiki != '' ) {
2658                         $p = $this->mInterwiki . ':';
2659                 }
2660
2661                 if ( 0 != $this->mNamespace ) {
2662                         $p .= $this->getNsText() . ':';
2663                 }
2664                 return $p . $name;
2665         }
2666
2667         /**
2668          * Returns a simple regex that will match on characters and sequences invalid in titles.
2669          * Note that this doesn't pick up many things that could be wrong with titles, but that
2670          * replacing this regex with something valid will make many titles valid.
2671          *
2672          * @return String regex string
2673          */
2674         static function getTitleInvalidRegex() {
2675                 static $rxTc = false;
2676                 if ( !$rxTc ) {
2677                         # Matching titles will be held as illegal.
2678                         $rxTc = '/' .
2679                                 # Any character not allowed is forbidden...
2680                                 '[^' . Title::legalChars() . ']' .
2681                                 # URL percent encoding sequences interfere with the ability
2682                                 # to round-trip titles -- you can't link to them consistently.
2683                                 '|%[0-9A-Fa-f]{2}' .
2684                                 # XML/HTML character references produce similar issues.
2685                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2686                                 '|&#[0-9]+;' .
2687                                 '|&#x[0-9A-Fa-f]+;' .
2688                                 '/S';
2689                 }
2690
2691                 return $rxTc;
2692         }
2693
2694         /**
2695          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2696          *
2697          * @param $text String containing title to capitalize
2698          * @param $ns int namespace index, defaults to NS_MAIN
2699          * @return String containing capitalized title
2700          */
2701         public static function capitalize( $text, $ns = NS_MAIN ) {
2702                 global $wgContLang;
2703
2704                 if ( MWNamespace::isCapitalized( $ns ) ) {
2705                         return $wgContLang->ucfirst( $text );
2706                 } else {
2707                         return $text;
2708                 }
2709         }
2710
2711         /**
2712          * Secure and split - main initialisation function for this object
2713          *
2714          * Assumes that mDbkeyform has been set, and is urldecoded
2715          * and uses underscores, but not otherwise munged.  This function
2716          * removes illegal characters, splits off the interwiki and
2717          * namespace prefixes, sets the other forms, and canonicalizes
2718          * everything.
2719          *
2720          * @return Bool true on success
2721          */
2722         private function secureAndSplit() {
2723                 global $wgContLang, $wgLocalInterwiki;
2724
2725                 # Initialisation
2726                 $this->mInterwiki = $this->mFragment = '';
2727                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2728
2729                 $dbkey = $this->mDbkeyform;
2730
2731                 # Strip Unicode bidi override characters.
2732                 # Sometimes they slip into cut-n-pasted page titles, where the
2733                 # override chars get included in list displays.
2734                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2735
2736                 # Clean up whitespace
2737                 # Note: use of the /u option on preg_replace here will cause
2738                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2739                 # conveniently disabling them.
2740                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2741                 $dbkey = trim( $dbkey, '_' );
2742
2743                 if ( $dbkey == '' ) {
2744                         return false;
2745                 }
2746
2747                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2748                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2749                         return false;
2750                 }
2751
2752                 $this->mDbkeyform = $dbkey;
2753
2754                 # Initial colon indicates main namespace rather than specified default
2755                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2756                 if ( ':' == $dbkey[0] ) {
2757                         $this->mNamespace = NS_MAIN;
2758                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2759                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2760                 }
2761
2762                 # Namespace or interwiki prefix
2763                 $firstPass = true;
2764                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2765                 do {
2766                         $m = array();
2767                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2768                                 $p = $m[1];
2769                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2770                                         # Ordinary namespace
2771                                         $dbkey = $m[2];
2772                                         $this->mNamespace = $ns;
2773                                         # For Talk:X pages, check if X has a "namespace" prefix
2774                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2775                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2776                                                         # Disallow Talk:File:x type titles...
2777                                                         return false;
2778                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2779                                                         # Disallow Talk:Interwiki:x type titles...
2780                                                         return false;
2781                                                 }
2782                                         }
2783                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2784                                         if ( !$firstPass ) {
2785                                                 # Can't make a local interwiki link to an interwiki link.
2786                                                 # That's just crazy!
2787                                                 return false;
2788                                         }
2789
2790                                         # Interwiki link
2791                                         $dbkey = $m[2];
2792                                         $this->mInterwiki = $wgContLang->lc( $p );
2793
2794                                         # Redundant interwiki prefix to the local wiki
2795                                         if ( $wgLocalInterwiki !== false
2796                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2797                                         {
2798                                                 if ( $dbkey == '' ) {
2799                                                         # Can't have an empty self-link
2800                                                         return false;
2801                                                 }
2802                                                 $this->mInterwiki = '';
2803                                                 $firstPass = false;
2804                                                 # Do another namespace split...
2805                                                 continue;
2806                                         }
2807
2808                                         # If there's an initial colon after the interwiki, that also
2809                                         # resets the default namespace
2810                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2811                                                 $this->mNamespace = NS_MAIN;
2812                                                 $dbkey = substr( $dbkey, 1 );
2813                                         }
2814                                 }
2815                                 # If there's no recognized interwiki or namespace,
2816                                 # then let the colon expression be part of the title.
2817                         }
2818                         break;
2819                 } while ( true );
2820
2821                 # We already know that some pages won't be in the database!
2822                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2823                         $this->mArticleID = 0;
2824                 }
2825                 $fragment = strstr( $dbkey, '#' );
2826                 if ( false !== $fragment ) {
2827                         $this->setFragment( $fragment );
2828                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2829                         # remove whitespace again: prevents "Foo_bar_#"
2830                         # becoming "Foo_bar_"
2831                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2832                 }
2833
2834                 # Reject illegal characters.
2835                 $rxTc = self::getTitleInvalidRegex();
2836                 if ( preg_match( $rxTc, $dbkey ) ) {
2837                         return false;
2838                 }
2839
2840                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2841                 # reachable due to the way web browsers deal with 'relative' URLs.
2842                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2843                 if ( strpos( $dbkey, '.' ) !== false &&
2844                          ( $dbkey === '.' || $dbkey === '..' ||
2845                            strpos( $dbkey, './' ) === 0  ||
2846                            strpos( $dbkey, '../' ) === 0 ||
2847                            strpos( $dbkey, '/./' ) !== false ||
2848                            strpos( $dbkey, '/../' ) !== false  ||
2849                            substr( $dbkey, -2 ) == '/.' ||
2850                            substr( $dbkey, -3 ) == '/..' ) )
2851                 {
2852                         return false;
2853                 }
2854
2855                 # Magic tilde sequences? Nu-uh!
2856                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2857                         return false;
2858                 }
2859
2860                 # Limit the size of titles to 255 bytes. This is typically the size of the
2861                 # underlying database field. We make an exception for special pages, which
2862                 # don't need to be stored in the database, and may edge over 255 bytes due
2863                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2864                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2865                   strlen( $dbkey ) > 512 )
2866                 {
2867                         return false;
2868                 }
2869
2870                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2871                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2872                 # other site might be case-sensitive.
2873                 $this->mUserCaseDBKey = $dbkey;
2874                 if ( $this->mInterwiki == '' ) {
2875                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2876                 }
2877
2878                 # Can't make a link to a namespace alone... "empty" local links can only be
2879                 # self-links with a fragment identifier.
2880                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2881                         return false;
2882                 }
2883
2884                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2885                 // IP names are not allowed for accounts, and can only be referring to
2886                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2887                 // there are numerous ways to present the same IP. Having sp:contribs scan
2888                 // them all is silly and having some show the edits and others not is
2889                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2890                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2891                         ? IP::sanitizeIP( $dbkey )
2892                         : $dbkey;
2893
2894                 // Any remaining initial :s are illegal.
2895                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
2896                         return false;
2897                 }
2898
2899                 # Fill fields
2900                 $this->mDbkeyform = $dbkey;
2901                 $this->mUrlform = wfUrlencode( $dbkey );
2902
2903                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2904
2905                 return true;
2906         }
2907
2908         /**
2909          * Set the fragment for this title. Removes the first character from the
2910          * specified fragment before setting, so it assumes you're passing it with
2911          * an initial "#".
2912          *
2913          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2914          * Still in active use privately.
2915          *
2916          * @param $fragment String text
2917          */
2918         public function setFragment( $fragment ) {
2919                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2920         }
2921
2922         /**
2923          * Get a Title object associated with the talk page of this article
2924          *
2925          * @return Title the object for the talk page
2926          */
2927         public function getTalkPage() {
2928                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2929         }
2930
2931         /**
2932          * Get a title object associated with the subject page of this
2933          * talk page
2934          *
2935          * @return Title the object for the subject page
2936          */
2937         public function getSubjectPage() {
2938                 // Is this the same title?
2939                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2940                 if ( $this->getNamespace() == $subjectNS ) {
2941                         return $this;
2942                 }
2943                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2944         }
2945
2946         /**
2947          * Get an array of Title objects linking to this Title
2948          * Also stores the IDs in the link cache.
2949          *
2950          * WARNING: do not use this function on arbitrary user-supplied titles!
2951          * On heavily-used templates it will max out the memory.
2952          *
2953          * @param $options Array: may be FOR UPDATE
2954          * @param $table String: table name
2955          * @param $prefix String: fields prefix
2956          * @return Array of Title objects linking here
2957          */
2958         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2959                 $linkCache = LinkCache::singleton();
2960
2961                 if ( count( $options ) > 0 ) {
2962                         $db = wfGetDB( DB_MASTER );
2963                 } else {
2964                         $db = wfGetDB( DB_SLAVE );
2965                 }
2966
2967                 $res = $db->select(
2968                         array( 'page', $table ),
2969                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2970                         array(
2971                                 "{$prefix}_from=page_id",
2972                                 "{$prefix}_namespace" => $this->getNamespace(),
2973                                 "{$prefix}_title"     => $this->getDBkey() ),
2974                         __METHOD__,
2975                         $options
2976                 );
2977
2978                 $retVal = array();
2979                 if ( $db->numRows( $res ) ) {
2980                         foreach ( $res as $row ) {
2981                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2982                                 if ( $titleObj ) {
2983                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
2984                                         $retVal[] = $titleObj;
2985                                 }
2986                         }
2987                 }
2988                 return $retVal;
2989         }
2990
2991         /**
2992          * Get an array of Title objects using this Title as a template
2993          * Also stores the IDs in the link cache.
2994          *
2995          * WARNING: do not use this function on arbitrary user-supplied titles!
2996          * On heavily-used templates it will max out the memory.
2997          *
2998          * @param $options Array: may be FOR UPDATE
2999          * @return Array of Title the Title objects linking here
3000          */
3001         public function getTemplateLinksTo( $options = array() ) {
3002                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3003         }
3004
3005         /**
3006          * Get an array of Title objects referring to non-existent articles linked from this page
3007          *
3008          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3009          * @return Array of Title the Title objects
3010          */
3011         public function getBrokenLinksFrom() {
3012                 if ( $this->getArticleId() == 0 ) {
3013                         # All links from article ID 0 are false positives
3014                         return array();
3015                 }
3016
3017                 $dbr = wfGetDB( DB_SLAVE );
3018                 $res = $dbr->select(
3019                         array( 'page', 'pagelinks' ),
3020                         array( 'pl_namespace', 'pl_title' ),
3021                         array(
3022                                 'pl_from' => $this->getArticleId(),
3023                                 'page_namespace IS NULL'
3024                         ),
3025                         __METHOD__, array(),
3026                         array(
3027                                 'page' => array(
3028                                         'LEFT JOIN',
3029                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3030                                 )
3031                         )
3032                 );
3033
3034                 $retVal = array();
3035                 foreach ( $res as $row ) {
3036                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3037                 }
3038                 return $retVal;
3039         }
3040
3041
3042         /**
3043          * Get a list of URLs to purge from the Squid cache when this
3044          * page changes
3045          *
3046          * @return Array of String the URLs
3047          */
3048         public function getSquidURLs() {
3049                 global $wgContLang;
3050
3051                 $urls = array(
3052                         $this->getInternalURL(),
3053                         $this->getInternalURL( 'action=history' )
3054                 );
3055
3056                 // purge variant urls as well
3057                 if ( $wgContLang->hasVariants() ) {
3058                         $variants = $wgContLang->getVariants();
3059                         foreach ( $variants as $vCode ) {
3060                                 $urls[] = $this->getInternalURL( '', $vCode );
3061                         }
3062                 }
3063
3064                 return $urls;
3065         }
3066
3067         /**
3068          * Purge all applicable Squid URLs
3069          */
3070         public function purgeSquid() {
3071                 global $wgUseSquid;
3072                 if ( $wgUseSquid ) {
3073                         $urls = $this->getSquidURLs();
3074                         $u = new SquidUpdate( $urls );
3075                         $u->doUpdate();
3076                 }
3077         }
3078
3079         /**
3080          * Move this page without authentication
3081          *
3082          * @param $nt Title the new page Title
3083          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3084          */
3085         public function moveNoAuth( &$nt ) {
3086                 return $this->moveTo( $nt, false );
3087         }
3088
3089         /**
3090          * Check whether a given move operation would be valid.
3091          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3092          *
3093          * @param $nt Title the new title
3094          * @param $auth Bool indicates whether $wgUser's permissions
3095          *  should be checked
3096          * @param $reason String is the log summary of the move, used for spam checking
3097          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3098          */
3099         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3100                 global $wgUser;
3101
3102                 $errors = array();
3103                 if ( !$nt ) {
3104                         // Normally we'd add this to $errors, but we'll get
3105                         // lots of syntax errors if $nt is not an object
3106                         return array( array( 'badtitletext' ) );
3107                 }
3108                 if ( $this->equals( $nt ) ) {
3109                         $errors[] = array( 'selfmove' );
3110                 }
3111                 if ( !$this->isMovable() ) {
3112                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3113                 }
3114                 if ( $nt->getInterwiki() != '' ) {
3115                         $errors[] = array( 'immobile-target-namespace-iw' );
3116                 }
3117                 if ( !$nt->isMovable() ) {
3118                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3119                 }
3120
3121                 $oldid = $this->getArticleID();
3122                 $newid = $nt->getArticleID();
3123
3124                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3125                         $errors[] = array( 'articleexists' );
3126                 }
3127                 if ( ( $this->getDBkey() == '' ) ||
3128                          ( !$oldid ) ||
3129                          ( $nt->getDBkey() == '' ) ) {
3130                         $errors[] = array( 'badarticleerror' );
3131                 }
3132
3133                 // Image-specific checks
3134                 if ( $this->getNamespace() == NS_FILE ) {
3135                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3136                 }
3137
3138                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3139                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3140                 }
3141
3142                 if ( $auth ) {
3143                         $errors = wfMergeErrorArrays( $errors,
3144                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3145                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3146                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3147                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3148                 }
3149
3150                 $match = EditPage::matchSummarySpamRegex( $reason );
3151                 if ( $match !== false ) {
3152                         // This is kind of lame, won't display nice
3153                         $errors[] = array( 'spamprotectiontext' );
3154                 }
3155
3156                 $err = null;
3157                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3158                         $errors[] = array( 'hookaborted', $err );
3159                 }
3160
3161                 # The move is allowed only if (1) the target doesn't exist, or
3162                 # (2) the target is a redirect to the source, and has no history
3163                 # (so we can undo bad moves right after they're done).
3164
3165                 if ( 0 != $newid ) { # Target exists; check for validity
3166                         if ( !$this->isValidMoveTarget( $nt ) ) {
3167                                 $errors[] = array( 'articleexists' );
3168                         }
3169                 } else {
3170                         $tp = $nt->getTitleProtection();
3171                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3172                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3173                                 $errors[] = array( 'cantmove-titleprotected' );
3174                         }
3175                 }
3176                 if ( empty( $errors ) ) {
3177                         return true;
3178                 }
3179                 return $errors;
3180         }
3181
3182         /**
3183          * Check if the requested move target is a valid file move target
3184          * @param Title $nt Target title
3185          * @return array List of errors
3186          */
3187         protected function validateFileMoveOperation( $nt ) {
3188                 global $wgUser;
3189
3190                 $errors = array();
3191
3192                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3193
3194                 $file = wfLocalFile( $this );
3195                 if ( $file->exists() ) {
3196                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3197                                 $errors[] = array( 'imageinvalidfilename' );
3198                         }
3199                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3200                                 $errors[] = array( 'imagetypemismatch' );
3201                         }
3202                 }
3203
3204                 if ( $nt->getNamespace() != NS_FILE ) {
3205                         $errors[] = array( 'imagenocrossnamespace' );
3206                         // From here we want to do checks on a file object, so if we can't
3207                         // create one, we must return.
3208                         return $errors;
3209                 }
3210
3211                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3212
3213                 $destFile = wfLocalFile( $nt );
3214                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3215                         $errors[] = array( 'file-exists-sharedrepo' );
3216                 }
3217
3218                 return $errors;
3219         }
3220
3221         /**
3222          * Move a title to a new location
3223          *
3224          * @param $nt Title the new title
3225          * @param $auth Bool indicates whether $wgUser's permissions
3226          *  should be checked
3227          * @param $reason String the reason for the move
3228          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3229          *  Ignored if the user doesn't have the suppressredirect right.
3230          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3231          */
3232         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3233                 global $wgUser;
3234                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3235                 if ( is_array( $err ) ) {
3236                         // Auto-block user's IP if the account was "hard" blocked
3237                         $wgUser->spreadAnyEditBlock();
3238                         return $err;
3239                 }
3240
3241                 // If it is a file, move it first.
3242                 // It is done before all other moving stuff is done because it's hard to revert.
3243                 $dbw = wfGetDB( DB_MASTER );
3244                 if ( $this->getNamespace() == NS_FILE ) {
3245                         $file = wfLocalFile( $this );
3246                         if ( $file->exists() ) {
3247                                 $status = $file->move( $nt );
3248                                 if ( !$status->isOk() ) {
3249                                         return $status->getErrorsArray();
3250                                 }
3251                         }
3252                 }
3253                 // Clear RepoGroup process cache
3254                 RepoGroup::singleton()->clearCache( $this );
3255                 RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3256
3257                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3258                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3259                 $protected = $this->isProtected();
3260                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3261
3262                 // Do the actual move
3263                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3264                 if ( is_array( $err ) ) {
3265                         # @todo FIXME: What about the File we have already moved?
3266                         $dbw->rollback();
3267                         return $err;
3268                 }
3269
3270                 $redirid = $this->getArticleID();
3271
3272                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3273                 // cl_timestamp, which may disturb time-based lists on some sites.
3274                 $prefixes = $dbw->select(
3275                         'categorylinks',
3276                         array( 'cl_sortkey_prefix', 'cl_to' ),
3277                         array( 'cl_from' => $pageid ),
3278                         __METHOD__
3279                 );
3280                 foreach ( $prefixes as $prefixRow ) {
3281                         $prefix = $prefixRow->cl_sortkey_prefix;
3282                         $catTo = $prefixRow->cl_to;
3283                         $dbw->update( 'categorylinks',
3284                                 array(
3285                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3286                                                 $nt->getCategorySortkey( $prefix ) ),
3287                                         'cl_timestamp=cl_timestamp' ),
3288                                 array(
3289                                         'cl_from' => $pageid,
3290                                         'cl_to' => $catTo ),
3291                                 __METHOD__
3292                         );
3293                 }
3294
3295                 if ( $protected ) {
3296                         # Protect the redirect title as the title used to be...
3297                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3298                                 array(
3299                                         'pr_page'    => $redirid,
3300                                         'pr_type'    => 'pr_type',
3301                                         'pr_level'   => 'pr_level',
3302                                         'pr_cascade' => 'pr_cascade',
3303                                         'pr_user'    => 'pr_user',
3304                                         'pr_expiry'  => 'pr_expiry'
3305                                 ),
3306                                 array( 'pr_page' => $pageid ),
3307                                 __METHOD__,
3308                                 array( 'IGNORE' )
3309                         );
3310                         # Update the protection log
3311                         $log = new LogPage( 'protect' );
3312                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3313                         if ( $reason ) {
3314                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3315                         }
3316                         // @todo FIXME: $params?
3317                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3318                 }
3319
3320                 # Update watchlists
3321                 $oldnamespace = $this->getNamespace() & ~1;
3322                 $newnamespace = $nt->getNamespace() & ~1;
3323                 $oldtitle = $this->getDBkey();
3324                 $newtitle = $nt->getDBkey();
3325
3326                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3327                         WatchedItem::duplicateEntries( $this, $nt );
3328                 }
3329
3330                 # Update search engine
3331                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3332                 $u->doUpdate();
3333                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3334                 $u->doUpdate();
3335
3336                 $dbw->commit();
3337
3338                 # Update site_stats
3339                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3340                         # No longer a content page
3341                         # Not viewed, edited, removing
3342                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3343                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3344                         # Now a content page
3345                         # Not viewed, edited, adding
3346                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3347                 } elseif ( $pageCountChange ) {
3348                         # Redirect added
3349                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3350                 } else {
3351                         # Nothing special
3352                         $u = false;
3353                 }
3354                 if ( $u ) {
3355                         $u->doUpdate();
3356                 }
3357
3358                 # Update message cache for interface messages
3359                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3360                         # @bug 17860: old article can be deleted, if this the case,
3361                         # delete it from message cache
3362                         if ( $this->getArticleID() === 0 ) {
3363                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3364                         } else {
3365                                 $rev = Revision::newFromTitle( $this );
3366                                 MessageCache::singleton()->replace( $this->getDBkey(), $rev->getText() );
3367                         }
3368                 }
3369                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3370                         $rev = Revision::newFromTitle( $nt );
3371                         MessageCache::singleton()->replace( $nt->getDBkey(), $rev->getText() );
3372                 }
3373
3374                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3375                 return true;
3376         }
3377
3378         /**
3379          * Move page to a title which is either a redirect to the
3380          * source page or nonexistent
3381          *
3382          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3383          * @param $reason String The reason for the move
3384          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3385          *   if the user doesn't have the suppressredirect right
3386          */
3387         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3388                 global $wgUser, $wgContLang;
3389
3390                 if ( $nt->exists() ) {
3391                         $moveOverRedirect = true;
3392                         $logType = 'move_redir';
3393                 } else {
3394                         $moveOverRedirect = false;
3395                         $logType = 'move';
3396                 }
3397
3398                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3399
3400                 $logEntry = new ManualLogEntry( 'move', $logType );
3401                 $logEntry->setPerformer( $wgUser );
3402                 $logEntry->setTarget( $this );
3403                 $logEntry->setComment( $reason );
3404                 $logEntry->setParameters( array(
3405                         '4::target' => $nt->getPrefixedText(),
3406                         '5::noredir' => $redirectSuppressed ? '1': '0',
3407                 ) );
3408
3409                 $formatter = LogFormatter::newFromEntry( $logEntry );
3410                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3411                 $comment = $formatter->getPlainActionText();
3412                 if ( $reason ) {
3413                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3414                 }
3415                 # Truncate for whole multibyte characters.
3416                 $comment = $wgContLang->truncate( $comment, 255 );
3417
3418                 $oldid = $this->getArticleID();
3419                 $latest = $this->getLatestRevID();
3420
3421                 $dbw = wfGetDB( DB_MASTER );
3422
3423                 if ( $moveOverRedirect ) {
3424                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3425
3426                         $newid = $nt->getArticleID();
3427                         $newns = $nt->getNamespace();
3428                         $newdbk = $nt->getDBkey();
3429
3430                         # Delete the old redirect. We don't save it to history since
3431                         # by definition if we've got here it's rather uninteresting.
3432                         # We have to remove it so that the next step doesn't trigger
3433                         # a conflict on the unique namespace+title index...
3434                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3435                         if ( !$dbw->cascadingDeletes() ) {
3436                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3437
3438                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3439                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3440                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3441                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3442                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3443                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3444                                 $dbw->delete( 'iwlinks', array( 'iwl_from' => $newid ), __METHOD__ );
3445                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3446                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3447                         }
3448                         // If the target page was recently created, it may have an entry in recentchanges still
3449                         $dbw->delete( 'recentchanges',
3450                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3451                                 __METHOD__
3452                         );
3453                 }
3454
3455                 # Save a null revision in the page's history notifying of the move
3456                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3457                 if ( !is_object( $nullRevision ) ) {
3458                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3459                 }
3460                 $nullRevId = $nullRevision->insertOn( $dbw );
3461
3462                 $now = wfTimestampNow();
3463                 # Change the name of the target page:
3464                 $dbw->update( 'page',
3465                         /* SET */ array(
3466                                 'page_touched'   => $dbw->timestamp( $now ),
3467                                 'page_namespace' => $nt->getNamespace(),
3468                                 'page_title'     => $nt->getDBkey(),
3469                                 'page_latest'    => $nullRevId,
3470                         ),
3471                         /* WHERE */ array( 'page_id' => $oldid ),
3472                         __METHOD__
3473                 );
3474                 $nt->resetArticleID( $oldid );
3475
3476                 $article = WikiPage::factory( $nt );
3477                 wfRunHooks( 'NewRevisionFromEditComplete',
3478                         array( $article, $nullRevision, $latest, $wgUser ) );
3479                 $article->setCachedLastEditTime( $now );
3480
3481                 # Recreate the redirect, this time in the other direction.
3482                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3483                         $mwRedir = MagicWord::get( 'redirect' );
3484                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3485                         $redirectArticle = WikiPage::factory( $this );
3486                         $newid = $redirectArticle->insertOn( $dbw );
3487                         if ( $newid ) { // sanity
3488                                 $redirectRevision = new Revision( array(
3489                                         'page'    => $newid,
3490                                         'comment' => $comment,
3491                                         'text'    => $redirectText ) );
3492                                 $redirectRevision->insertOn( $dbw );
3493                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3494
3495                                 wfRunHooks( 'NewRevisionFromEditComplete',
3496                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3497
3498                                 # Now, we record the link from the redirect to the new title.
3499                                 # It should have no other outgoing links...
3500                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3501                                 $dbw->insert( 'pagelinks',
3502                                         array(
3503                                                 'pl_from'      => $newid,
3504                                                 'pl_namespace' => $nt->getNamespace(),
3505                                                 'pl_title'     => $nt->getDBkey() ),
3506                                         __METHOD__ );
3507                         }
3508                 } else {
3509                         $this->resetArticleID( 0 );
3510                 }
3511
3512                 # Log the move
3513                 $logid = $logEntry->insert();
3514                 $logEntry->publish( $logid );
3515
3516                 # Purge caches for old and new titles
3517                 if ( $moveOverRedirect ) {
3518                         # A simple purge is enough when moving over a redirect
3519                         $nt->purgeSquid();
3520                 } else {
3521                         # Purge caches as per article creation, including any pages that link to this title
3522                         Article::onArticleCreate( $nt );
3523                 }
3524                 $this->purgeSquid();
3525         }
3526
3527         /**
3528          * Move this page's subpages to be subpages of $nt
3529          *
3530          * @param $nt Title Move target
3531          * @param $auth bool Whether $wgUser's permissions should be checked
3532          * @param $reason string The reason for the move
3533          * @param $createRedirect bool Whether to create redirects from the old subpages to
3534          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3535          * @return mixed array with old page titles as keys, and strings (new page titles) or
3536          *     arrays (errors) as values, or an error array with numeric indices if no pages
3537          *     were moved
3538          */
3539         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3540                 global $wgMaximumMovedPages;
3541                 // Check permissions
3542                 if ( !$this->userCan( 'move-subpages' ) ) {
3543                         return array( 'cant-move-subpages' );
3544                 }
3545                 // Do the source and target namespaces support subpages?
3546                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3547                         return array( 'namespace-nosubpages',
3548                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3549                 }
3550                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3551                         return array( 'namespace-nosubpages',
3552                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3553                 }
3554
3555                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3556                 $retval = array();
3557                 $count = 0;
3558                 foreach ( $subpages as $oldSubpage ) {
3559                         $count++;
3560                         if ( $count > $wgMaximumMovedPages ) {
3561                                 $retval[$oldSubpage->getPrefixedTitle()] =
3562                                                 array( 'movepage-max-pages',
3563                                                         $wgMaximumMovedPages );
3564                                 break;
3565                         }
3566
3567                         // We don't know whether this function was called before
3568                         // or after moving the root page, so check both
3569                         // $this and $nt
3570                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3571                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3572                         {
3573                                 // When moving a page to a subpage of itself,
3574                                 // don't move it twice
3575                                 continue;
3576                         }
3577                         $newPageName = preg_replace(
3578                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3579                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3580                                         $oldSubpage->getDBkey() );
3581                         if ( $oldSubpage->isTalkPage() ) {
3582                                 $newNs = $nt->getTalkPage()->getNamespace();
3583                         } else {
3584                                 $newNs = $nt->getSubjectPage()->getNamespace();
3585                         }
3586                         # Bug 14385: we need makeTitleSafe because the new page names may
3587                         # be longer than 255 characters.
3588                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3589
3590                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3591                         if ( $success === true ) {
3592                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3593                         } else {
3594                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3595                         }
3596                 }
3597                 return $retval;
3598         }
3599
3600         /**
3601          * Checks if this page is just a one-rev redirect.
3602          * Adds lock, so don't use just for light purposes.
3603          *
3604          * @return Bool
3605          */
3606         public function isSingleRevRedirect() {
3607                 $dbw = wfGetDB( DB_MASTER );
3608                 # Is it a redirect?
3609                 $row = $dbw->selectRow( 'page',
3610                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3611                         $this->pageCond(),
3612                         __METHOD__,
3613                         array( 'FOR UPDATE' )
3614                 );
3615                 # Cache some fields we may want
3616                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3617                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3618                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3619                 if ( !$this->mRedirect ) {
3620                         return false;
3621                 }
3622                 # Does the article have a history?
3623                 $row = $dbw->selectField( array( 'page', 'revision' ),
3624                         'rev_id',
3625                         array( 'page_namespace' => $this->getNamespace(),
3626                                 'page_title' => $this->getDBkey(),
3627                                 'page_id=rev_page',
3628                                 'page_latest != rev_id'
3629                         ),
3630                         __METHOD__,
3631                         array( 'FOR UPDATE' )
3632                 );
3633                 # Return true if there was no history
3634                 return ( $row === false );
3635         }
3636
3637         /**
3638          * Checks if $this can be moved to a given Title
3639          * - Selects for update, so don't call it unless you mean business
3640          *
3641          * @param $nt Title the new title to check
3642          * @return Bool
3643          */
3644         public function isValidMoveTarget( $nt ) {
3645                 # Is it an existing file?
3646                 if ( $nt->getNamespace() == NS_FILE ) {
3647                         $file = wfLocalFile( $nt );
3648                         if ( $file->exists() ) {
3649                                 wfDebug( __METHOD__ . ": file exists\n" );
3650                                 return false;
3651                         }
3652                 }
3653                 # Is it a redirect with no history?
3654                 if ( !$nt->isSingleRevRedirect() ) {
3655                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3656                         return false;
3657                 }
3658                 # Get the article text
3659                 $rev = Revision::newFromTitle( $nt );
3660                 if( !is_object( $rev ) ){
3661                         return false;
3662                 }
3663                 $text = $rev->getText();
3664                 # Does the redirect point to the source?
3665                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3666                 $m = array();
3667                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3668                         $redirTitle = Title::newFromText( $m[1] );
3669                         if ( !is_object( $redirTitle ) ||
3670                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3671                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3672                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3673                                 return false;
3674                         }
3675                 } else {
3676                         # Fail safe
3677                         wfDebug( __METHOD__ . ": failsafe\n" );
3678                         return false;
3679                 }
3680                 return true;
3681         }
3682
3683         /**
3684          * Can this title be added to a user's watchlist?
3685          *
3686          * @return Bool TRUE or FALSE
3687          */
3688         public function isWatchable() {
3689                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3690         }
3691
3692         /**
3693          * Get categories to which this Title belongs and return an array of
3694          * categories' names.
3695          *
3696          * @return Array of parents in the form:
3697          *        $parent => $currentarticle
3698          */
3699         public function getParentCategories() {
3700                 global $wgContLang;
3701
3702                 $data = array();
3703
3704                 $titleKey = $this->getArticleId();
3705
3706                 if ( $titleKey === 0 ) {
3707                         return $data;
3708                 }
3709
3710                 $dbr = wfGetDB( DB_SLAVE );
3711
3712                 $res = $dbr->select( 'categorylinks', '*',
3713                         array(
3714                                 'cl_from' => $titleKey,
3715                         ),
3716                         __METHOD__,
3717                         array()
3718                 );
3719
3720                 if ( $dbr->numRows( $res ) > 0 ) {
3721                         foreach ( $res as $row ) {
3722                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3723                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3724                         }
3725                 }
3726                 return $data;
3727         }
3728
3729         /**
3730          * Get a tree of parent categories
3731          *
3732          * @param $children Array with the children in the keys, to check for circular refs
3733          * @return Array Tree of parent categories
3734          */
3735         public function getParentCategoryTree( $children = array() ) {
3736                 $stack = array();
3737                 $parents = $this->getParentCategories();
3738
3739                 if ( $parents ) {
3740                         foreach ( $parents as $parent => $current ) {
3741                                 if ( array_key_exists( $parent, $children ) ) {
3742                                         # Circular reference
3743                                         $stack[$parent] = array();
3744                                 } else {
3745                                         $nt = Title::newFromText( $parent );
3746                                         if ( $nt ) {
3747                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3748                                         }
3749                                 }
3750                         }
3751                 }
3752
3753                 return $stack;
3754         }
3755
3756         /**
3757          * Get an associative array for selecting this title from
3758          * the "page" table
3759          *
3760          * @return Array suitable for the $where parameter of DB::select()
3761          */
3762         public function pageCond() {
3763                 if ( $this->mArticleID > 0 ) {
3764                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3765                         return array( 'page_id' => $this->mArticleID );
3766                 } else {
3767                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3768                 }
3769         }
3770
3771         /**
3772          * Get the revision ID of the previous revision
3773          *
3774          * @param $revId Int Revision ID. Get the revision that was before this one.
3775          * @param $flags Int Title::GAID_FOR_UPDATE
3776          * @return Int|Bool Old revision ID, or FALSE if none exists
3777          */
3778         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3779                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3780                 return $db->selectField( 'revision', 'rev_id',
3781                         array(
3782                                 'rev_page' => $this->getArticleId( $flags ),
3783                                 'rev_id < ' . intval( $revId )
3784                         ),
3785                         __METHOD__,
3786                         array( 'ORDER BY' => 'rev_id DESC' )
3787                 );
3788         }
3789
3790         /**
3791          * Get the revision ID of the next revision
3792          *
3793          * @param $revId Int Revision ID. Get the revision that was after this one.
3794          * @param $flags Int Title::GAID_FOR_UPDATE
3795          * @return Int|Bool Next revision ID, or FALSE if none exists
3796          */
3797         public function getNextRevisionID( $revId, $flags = 0 ) {
3798                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3799                 return $db->selectField( 'revision', 'rev_id',
3800                         array(
3801                                 'rev_page' => $this->getArticleId( $flags ),
3802                                 'rev_id > ' . intval( $revId )
3803                         ),
3804                         __METHOD__,
3805                         array( 'ORDER BY' => 'rev_id' )
3806                 );
3807         }
3808
3809         /**
3810          * Get the first revision of the page
3811          *
3812          * @param $flags Int Title::GAID_FOR_UPDATE
3813          * @return Revision|Null if page doesn't exist
3814          */
3815         public function getFirstRevision( $flags = 0 ) {
3816                 $pageId = $this->getArticleId( $flags );
3817                 if ( $pageId ) {
3818                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3819                         $row = $db->selectRow( 'revision', '*',
3820                                 array( 'rev_page' => $pageId ),
3821                                 __METHOD__,
3822                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3823                         );
3824                         if ( $row ) {
3825                                 return new Revision( $row );
3826                         }
3827                 }
3828                 return null;
3829         }
3830
3831         /**
3832          * Get the oldest revision timestamp of this page
3833          *
3834          * @param $flags Int Title::GAID_FOR_UPDATE
3835          * @return String: MW timestamp
3836          */
3837         public function getEarliestRevTime( $flags = 0 ) {
3838                 $rev = $this->getFirstRevision( $flags );
3839                 return $rev ? $rev->getTimestamp() : null;
3840         }
3841
3842         /**
3843          * Check if this is a new page
3844          *
3845          * @return bool
3846          */
3847         public function isNewPage() {
3848                 $dbr = wfGetDB( DB_SLAVE );
3849                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3850         }
3851
3852         /**
3853          * Get the number of revisions between the given revision.
3854          * Used for diffs and other things that really need it.
3855          *
3856          * @param $old int|Revision Old revision or rev ID (first before range)
3857          * @param $new int|Revision New revision or rev ID (first after range)
3858          * @return Int Number of revisions between these revisions.
3859          */
3860         public function countRevisionsBetween( $old, $new ) {
3861                 if ( !( $old instanceof Revision ) ) {
3862                         $old = Revision::newFromTitle( $this, (int)$old );
3863                 }
3864                 if ( !( $new instanceof Revision ) ) {
3865                         $new = Revision::newFromTitle( $this, (int)$new );
3866                 }
3867                 if ( !$old || !$new ) {
3868                         return 0; // nothing to compare
3869                 }
3870                 $dbr = wfGetDB( DB_SLAVE );
3871                 return (int)$dbr->selectField( 'revision', 'count(*)',
3872                         array(
3873                                 'rev_page' => $this->getArticleId(),
3874                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3875                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3876                         ),
3877                         __METHOD__
3878                 );
3879         }
3880
3881         /**
3882          * Get the number of authors between the given revision IDs.
3883          * Used for diffs and other things that really need it.
3884          *
3885          * @param $old int|Revision Old revision or rev ID (first before range)
3886          * @param $new int|Revision New revision or rev ID (first after range)
3887          * @param $limit Int Maximum number of authors
3888          * @return Int Number of revision authors between these revisions.
3889          */
3890         public function countAuthorsBetween( $old, $new, $limit ) {
3891                 if ( !( $old instanceof Revision ) ) {
3892                         $old = Revision::newFromTitle( $this, (int)$old );
3893                 }
3894                 if ( !( $new instanceof Revision ) ) {
3895                         $new = Revision::newFromTitle( $this, (int)$new );
3896                 }
3897                 if ( !$old || !$new ) {
3898                         return 0; // nothing to compare
3899                 }
3900                 $dbr = wfGetDB( DB_SLAVE );
3901                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3902                         array(
3903                                 'rev_page' => $this->getArticleID(),
3904                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3905                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3906                         ), __METHOD__,
3907                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3908                 );
3909                 return (int)$dbr->numRows( $res );
3910         }
3911
3912         /**
3913          * Compare with another title.
3914          *
3915          * @param $title Title
3916          * @return Bool
3917          */
3918         public function equals( Title $title ) {
3919                 // Note: === is necessary for proper matching of number-like titles.
3920                 return $this->getInterwiki() === $title->getInterwiki()
3921                         && $this->getNamespace() == $title->getNamespace()
3922                         && $this->getDBkey() === $title->getDBkey();
3923         }
3924
3925         /**
3926          * Check if this title is a subpage of another title
3927          *
3928          * @param $title Title
3929          * @return Bool
3930          */
3931         public function isSubpageOf( Title $title ) {
3932                 return $this->getInterwiki() === $title->getInterwiki()
3933                         && $this->getNamespace() == $title->getNamespace()
3934                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
3935         }
3936
3937         /**
3938          * Callback for usort() to do title sorts by (namespace, title)
3939          *
3940          * @param $a Title
3941          * @param $b Title
3942          *
3943          * @return Integer: result of string comparison, or namespace comparison
3944          */
3945         public static function compare( $a, $b ) {
3946                 if ( $a->getNamespace() == $b->getNamespace() ) {
3947                         return strcmp( $a->getText(), $b->getText() );
3948                 } else {
3949                         return $a->getNamespace() - $b->getNamespace();
3950                 }
3951         }
3952
3953         /**
3954          * Return a string representation of this title
3955          *
3956          * @return String representation of this title
3957          */
3958         public function __toString() {
3959                 return $this->getPrefixedText();
3960         }
3961
3962         /**
3963          * Check if page exists.  For historical reasons, this function simply
3964          * checks for the existence of the title in the page table, and will
3965          * thus return false for interwiki links, special pages and the like.
3966          * If you want to know if a title can be meaningfully viewed, you should
3967          * probably call the isKnown() method instead.
3968          *
3969          * @return Bool
3970          */
3971         public function exists() {
3972                 return $this->getArticleId() != 0;
3973         }
3974
3975         /**
3976          * Should links to this title be shown as potentially viewable (i.e. as
3977          * "bluelinks"), even if there's no record by this title in the page
3978          * table?
3979          *
3980          * This function is semi-deprecated for public use, as well as somewhat
3981          * misleadingly named.  You probably just want to call isKnown(), which
3982          * calls this function internally.
3983          *
3984          * (ISSUE: Most of these checks are cheap, but the file existence check
3985          * can potentially be quite expensive.  Including it here fixes a lot of
3986          * existing code, but we might want to add an optional parameter to skip
3987          * it and any other expensive checks.)
3988          *
3989          * @return Bool
3990          */
3991         public function isAlwaysKnown() {
3992                 if ( $this->mInterwiki != '' ) {
3993                         return true;  // any interwiki link might be viewable, for all we know
3994                 }
3995                 switch( $this->mNamespace ) {
3996                         case NS_MEDIA:
3997                         case NS_FILE:
3998                                 // file exists, possibly in a foreign repo
3999                                 return (bool)wfFindFile( $this );
4000                         case NS_SPECIAL:
4001                                 // valid special page
4002                                 return SpecialPageFactory::exists( $this->getDBkey() );
4003                         case NS_MAIN:
4004                                 // selflink, possibly with fragment
4005                                 return $this->mDbkeyform == '';
4006                         case NS_MEDIAWIKI:
4007                                 // known system message
4008                                 return $this->hasSourceText() !== false;
4009                         default:
4010                                 return false;
4011                 }
4012         }
4013
4014         /**
4015          * Does this title refer to a page that can (or might) be meaningfully
4016          * viewed?  In particular, this function may be used to determine if
4017          * links to the title should be rendered as "bluelinks" (as opposed to
4018          * "redlinks" to non-existent pages).
4019          *
4020          * @return Bool
4021          */
4022         public function isKnown() {
4023                 return $this->isAlwaysKnown() || $this->exists();
4024         }
4025
4026         /**
4027          * Does this page have source text?
4028          *
4029          * @return Boolean
4030          */
4031         public function hasSourceText() {
4032                 if ( $this->exists() ) {
4033                         return true;
4034                 }
4035
4036                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4037                         // If the page doesn't exist but is a known system message, default
4038                         // message content will be displayed, same for language subpages-
4039                         // Use always content language to avoid loading hundreds of languages
4040                         // to get the link color.
4041                         global $wgContLang;
4042                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4043                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4044                         return $message->exists();
4045                 }
4046
4047                 return false;
4048         }
4049
4050         /**
4051          * Get the default message text or false if the message doesn't exist
4052          *
4053          * @return String or false
4054          */
4055         public function getDefaultMessageText() {
4056                 global $wgContLang;
4057
4058                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4059                         return false;
4060                 }
4061
4062                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4063                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4064
4065                 if ( $message->exists() ) {
4066                         return $message->plain();
4067                 } else {
4068                         return false;
4069                 }
4070         }
4071
4072         /**
4073          * Is this in a namespace that allows actual pages?
4074          *
4075          * @return Bool
4076          * @internal note -- uses hardcoded namespace index instead of constants
4077          */
4078         public function canExist() {
4079                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
4080         }
4081
4082         /**
4083          * Update page_touched timestamps and send squid purge messages for
4084          * pages linking to this title. May be sent to the job queue depending
4085          * on the number of links. Typically called on create and delete.
4086          */
4087         public function touchLinks() {
4088                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4089                 $u->doUpdate();
4090
4091                 if ( $this->getNamespace() == NS_CATEGORY ) {
4092                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4093                         $u->doUpdate();
4094                 }
4095         }
4096
4097         /**
4098          * Get the last touched timestamp
4099          *
4100          * @param $db DatabaseBase: optional db
4101          * @return String last-touched timestamp
4102          */
4103         public function getTouched( $db = null ) {
4104                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4105                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4106                 return $touched;
4107         }
4108
4109         /**
4110          * Get the timestamp when this page was updated since the user last saw it.
4111          *
4112          * @param $user User
4113          * @return String|Null
4114          */
4115         public function getNotificationTimestamp( $user = null ) {
4116                 global $wgUser, $wgShowUpdatedMarker;
4117                 // Assume current user if none given
4118                 if ( !$user ) {
4119                         $user = $wgUser;
4120                 }
4121                 // Check cache first
4122                 $uid = $user->getId();
4123                 // avoid isset here, as it'll return false for null entries
4124                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4125                         return $this->mNotificationTimestamp[$uid];
4126                 }
4127                 if ( !$uid || !$wgShowUpdatedMarker ) {
4128                         return $this->mNotificationTimestamp[$uid] = false;
4129                 }
4130                 // Don't cache too much!
4131                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4132                         $this->mNotificationTimestamp = array();
4133                 }
4134                 $dbr = wfGetDB( DB_SLAVE );
4135                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4136                         'wl_notificationtimestamp',
4137                         array( 'wl_namespace' => $this->getNamespace(),
4138                                 'wl_title' => $this->getDBkey(),
4139                                 'wl_user' => $user->getId()
4140                         ),
4141                         __METHOD__
4142                 );
4143                 return $this->mNotificationTimestamp[$uid];
4144         }
4145
4146         /**
4147          * Generate strings used for xml 'id' names in monobook tabs
4148          *
4149          * @param $prepend string defaults to 'nstab-'
4150          * @return String XML 'id' name
4151          */
4152         public function getNamespaceKey( $prepend = 'nstab-' ) {
4153                 global $wgContLang;
4154                 // Gets the subject namespace if this title
4155                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4156                 // Checks if cononical namespace name exists for namespace
4157                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4158                         // Uses canonical namespace name
4159                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4160                 } else {
4161                         // Uses text of namespace
4162                         $namespaceKey = $this->getSubjectNsText();
4163                 }
4164                 // Makes namespace key lowercase
4165                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4166                 // Uses main
4167                 if ( $namespaceKey == '' ) {
4168                         $namespaceKey = 'main';
4169                 }
4170                 // Changes file to image for backwards compatibility
4171                 if ( $namespaceKey == 'file' ) {
4172                         $namespaceKey = 'image';
4173                 }
4174                 return $prepend . $namespaceKey;
4175         }
4176
4177         /**
4178          * Returns true if this is a special page.
4179          *
4180          * @return boolean
4181          */
4182         public function isSpecialPage() {
4183                 return $this->getNamespace() == NS_SPECIAL;
4184         }
4185
4186         /**
4187          * Returns true if this title resolves to the named special page
4188          *
4189          * @param $name String The special page name
4190          * @return boolean
4191          */
4192         public function isSpecial( $name ) {
4193                 if ( $this->isSpecialPage() ) {
4194                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4195                         if ( $name == $thisName ) {
4196                                 return true;
4197                         }
4198                 }
4199                 return false;
4200         }
4201
4202         /**
4203          * If the Title refers to a special page alias which is not the local default, resolve
4204          * the alias, and localise the name as necessary.  Otherwise, return $this
4205          *
4206          * @return Title
4207          */
4208         public function fixSpecialName() {
4209                 if ( $this->isSpecialPage() ) {
4210                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4211                         if ( $canonicalName ) {
4212                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
4213                                 if ( $localName != $this->mDbkeyform ) {
4214                                         return Title::makeTitle( NS_SPECIAL, $localName );
4215                                 }
4216                         }
4217                 }
4218                 return $this;
4219         }
4220
4221         /**
4222          * Is this Title in a namespace which contains content?
4223          * In other words, is this a content page, for the purposes of calculating
4224          * statistics, etc?
4225          *
4226          * @return Boolean
4227          */
4228         public function isContentPage() {
4229                 return MWNamespace::isContent( $this->getNamespace() );
4230         }
4231
4232         /**
4233          * Get all extant redirects to this Title
4234          *
4235          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4236          * @return Array of Title redirects to this title
4237          */
4238         public function getRedirectsHere( $ns = null ) {
4239                 $redirs = array();
4240
4241                 $dbr = wfGetDB( DB_SLAVE );
4242                 $where = array(
4243                         'rd_namespace' => $this->getNamespace(),
4244                         'rd_title' => $this->getDBkey(),
4245                         'rd_from = page_id'
4246                 );
4247                 if ( !is_null( $ns ) ) {
4248                         $where['page_namespace'] = $ns;
4249                 }
4250
4251                 $res = $dbr->select(
4252                         array( 'redirect', 'page' ),
4253                         array( 'page_namespace', 'page_title' ),
4254                         $where,
4255                         __METHOD__
4256                 );
4257
4258                 foreach ( $res as $row ) {
4259                         $redirs[] = self::newFromRow( $row );
4260                 }
4261                 return $redirs;
4262         }
4263
4264         /**
4265          * Check if this Title is a valid redirect target
4266          *
4267          * @return Bool
4268          */
4269         public function isValidRedirectTarget() {
4270                 global $wgInvalidRedirectTargets;
4271
4272                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4273                 if ( $this->isSpecial( 'Userlogout' ) ) {
4274                         return false;
4275                 }
4276
4277                 foreach ( $wgInvalidRedirectTargets as $target ) {
4278                         if ( $this->isSpecial( $target ) ) {
4279                                 return false;
4280                         }
4281                 }
4282
4283                 return true;
4284         }
4285
4286         /**
4287          * Get a backlink cache object
4288          *
4289          * @return BacklinkCache
4290          */
4291         function getBacklinkCache() {
4292                 if ( is_null( $this->mBacklinkCache ) ) {
4293                         $this->mBacklinkCache = new BacklinkCache( $this );
4294                 }
4295                 return $this->mBacklinkCache;
4296         }
4297
4298         /**
4299          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4300          *
4301          * @return Boolean
4302          */
4303         public function canUseNoindex() {
4304                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4305
4306                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4307                         ? $wgContentNamespaces
4308                         : $wgExemptFromUserRobotsControl;
4309
4310                 return !in_array( $this->mNamespace, $bannedNamespaces );
4311
4312         }
4313
4314         /**
4315          * Returns restriction types for the current Title
4316          *
4317          * @return array applicable restriction types
4318          */
4319         public function getRestrictionTypes() {
4320                 if ( $this->isSpecialPage() ) {
4321                         return array();
4322                 }
4323
4324                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4325
4326                 if ( $this->getNamespace() != NS_FILE ) {
4327                         # Remove the upload restriction for non-file titles
4328                         $types = array_diff( $types, array( 'upload' ) );
4329                 }
4330
4331                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4332
4333                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4334                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4335
4336                 return $types;
4337         }
4338         /**
4339          * Get a filtered list of all restriction types supported by this wiki.
4340          * @param bool $exists True to get all restriction types that apply to
4341          * titles that do exist, False for all restriction types that apply to
4342          * titles that do not exist
4343          * @return array
4344          */
4345         public static function getFilteredRestrictionTypes( $exists = true ) {
4346                 global $wgRestrictionTypes;
4347                 $types = $wgRestrictionTypes;
4348                 if ( $exists ) {
4349                         # Remove the create restriction for existing titles
4350                         $types = array_diff( $types, array( 'create' ) );
4351                 } else {
4352                         # Only the create and upload restrictions apply to non-existing titles
4353                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4354                 }
4355                 return $types;
4356         }
4357
4358         /**
4359          * Returns the raw sort key to be used for categories, with the specified
4360          * prefix.  This will be fed to Collation::getSortKey() to get a
4361          * binary sortkey that can be used for actual sorting.
4362          *
4363          * @param $prefix string The prefix to be used, specified using
4364          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4365          *   prefix.
4366          * @return string
4367          */
4368         public function getCategorySortkey( $prefix = '' ) {
4369                 $unprefixed = $this->getText();
4370
4371                 // Anything that uses this hook should only depend
4372                 // on the Title object passed in, and should probably
4373                 // tell the users to run updateCollations.php --force
4374                 // in order to re-sort existing category relations.
4375                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4376                 if ( $prefix !== '' ) {
4377                         # Separate with a line feed, so the unprefixed part is only used as
4378                         # a tiebreaker when two pages have the exact same prefix.
4379                         # In UCA, tab is the only character that can sort above LF
4380                         # so we strip both of them from the original prefix.
4381                         $prefix = strtr( $prefix, "\n\t", '  ' );
4382                         return "$prefix\n$unprefixed";
4383                 }
4384                 return $unprefixed;
4385         }
4386
4387         /**
4388          * Get the language in which the content of this page is written.
4389          * Defaults to $wgContLang, but in certain cases it can be e.g.
4390          * $wgLang (such as special pages, which are in the user language).
4391          *
4392          * @since 1.18
4393          * @return object Language
4394          */
4395         public function getPageLanguage() {
4396                 global $wgLang;
4397                 if ( $this->isSpecialPage() ) {
4398                         // special pages are in the user language
4399                         return $wgLang;
4400                 } elseif ( $this->isCssOrJsPage() ) {
4401                         // css/js should always be LTR and is, in fact, English
4402                         return wfGetLangObj( 'en' );
4403                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4404                         // Parse mediawiki messages with correct target language
4405                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4406                         return wfGetLangObj( $lang );
4407                 }
4408                 global $wgContLang;
4409                 // If nothing special, it should be in the wiki content language
4410                 $pageLang = $wgContLang;
4411                 // Hook at the end because we don't want to override the above stuff
4412                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4413                 return wfGetLangObj( $pageLang );
4414         }
4415 }