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          * Get the prefixed DB key associated with an ID
 447          *
 448          * @param $id Int the page_id of the article
 449          * @return Title an object representing the article, or NULL if no such article was found
 450          */
 451         public static function nameOf( $id ) {
 452                 $dbr = wfGetDB( DB_SLAVE );
 453
 454                 $s = $dbr->selectRow(
 455                         'page',
 456                         array( 'page_namespace', 'page_title' ),
 457                         array( 'page_id' => $id ),
 458                         __METHOD__
 459                 );
 460                 if ( $s === false ) {
 461                         return null;
 462                 }
 463
 464                 $n = self::makeName( $s->page_namespace, $s->page_title );
 465                 return $n;
 466         }
 467
 468         /**
 469          * Get a regex character class describing the legal characters in a link
 470          *
 471          * @return String the list of characters, not delimited
 472          */
 473         public static function legalChars() {
 474                 global $wgLegalTitleChars;
 475                 return $wgLegalTitleChars;
 476         }
 477
 478         /**
 479          * Get a string representation of a title suitable for
 480          * including in a search index
 481          *
 482          * @param $ns Int a namespace index
 483          * @param $title String text-form main part
 484          * @return String a stripped-down title string ready for the search index
 485          */
 486         public static function indexTitle( $ns, $title ) {
 487                 global $wgContLang;
 488
 489                 $lc = SearchEngine::legalSearchChars() . '&#;';
 490                 $t = $wgContLang->normalizeForSearch( $title );
 491                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 492                 $t = $wgContLang->lc( $t );
 493
 494                 # Handle 's, s'
 495                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 496                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 497
 498                 $t = preg_replace( "/\\s+/", ' ', $t );
 499
 500                 if ( $ns == NS_FILE ) {
 501                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 502                 }
 503                 return trim( $t );
 504         }
 505
 506         /**
 507          * Make a prefixed DB key from a DB key and a namespace index
 508          *
 509          * @param $ns Int numerical representation of the namespace
 510          * @param $title String the DB key form the title
 511          * @param $fragment String The link fragment (after the "#")
 512          * @param $interwiki String The interwiki prefix
 513          * @return String the prefixed form of the title
 514          */
 515         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 516                 global $wgContLang;
 517
 518                 $namespace = $wgContLang->getNsText( $ns );
 519                 $name = $namespace == '' ? $title : "$namespace:$title";
 520                 if ( strval( $interwiki ) != '' ) {
 521                         $name = "$interwiki:$name";
 522                 }
 523                 if ( strval( $fragment ) != '' ) {
 524                         $name .= '#' . $fragment;
 525                 }
 526                 return $name;
 527         }
 528
 529         /**
 530          * Escape a text fragment, say from a link, for a URL
 531          *
 532          * @param $fragment string containing a URL or link fragment (after the "#")
 533          * @return String: escaped string
 534          */
 535         static function escapeFragmentForURL( $fragment ) {
 536                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 537                 # fragments appear not to work in IE (at least up to 7) or in at least
 538                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 539                 # to care if they aren't encoded.
 540                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 541         }
 542
 543         /**
 544          * Determine whether the object refers to a page within
 545          * this project.
 546          *
 547          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 548          */
 549         public function isLocal() {
 550                 if ( $this->mInterwiki != '' ) {
 551                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 552                 } else {
 553                         return true;
 554                 }
 555         }
 556
 557         /**
 558          * Is this Title interwiki?
 559          *
 560          * @return Bool
 561          */
 562         public function isExternal() {
 563                 return ( $this->mInterwiki != '' );
 564         }
 565
 566         /**
 567          * Get the interwiki prefix (or null string)
 568          *
 569          * @return String Interwiki prefix
 570          */
 571         public function getInterwiki() {
 572                 return $this->mInterwiki;
 573         }
 574
 575         /**
 576          * Determine whether the object refers to a page within
 577          * this project and is transcludable.
 578          *
 579          * @return Bool TRUE if this is transcludable
 580          */
 581         public function isTrans() {
 582                 if ( $this->mInterwiki == '' ) {
 583                         return false;
 584                 }
 585
 586                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 587         }
 588
 589         /**
 590          * Returns the DB name of the distant wiki which owns the object.
 591          *
 592          * @return String the DB name
 593          */
 594         public function getTransWikiID() {
 595                 if ( $this->mInterwiki == '' ) {
 596                         return false;
 597                 }
 598
 599                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 600         }
 601
 602         /**
 603          * Get the text form (spaces not underscores) of the main part
 604          *
 605          * @return String Main part of the title
 606          */
 607         public function getText() {
 608                 return $this->mTextform;
 609         }
 610
 611         /**
 612          * Get the URL-encoded form of the main part
 613          *
 614          * @return String Main part of the title, URL-encoded
 615          */
 616         public function getPartialURL() {
 617                 return $this->mUrlform;
 618         }
 619
 620         /**
 621          * Get the main part with underscores
 622          *
 623          * @return String: Main part of the title, with underscores
 624          */
 625         public function getDBkey() {
 626                 return $this->mDbkeyform;
 627         }
 628
 629         /**
 630          * Get the namespace index, i.e. one of the NS_xxxx constants.
 631          *
 632          * @return Integer: Namespace index
 633          */
 634         public function getNamespace() {
 635                 return $this->mNamespace;
 636         }
 637
 638         /**
 639          * Get the namespace text
 640          *
 641          * @return String: Namespace text
 642          */
 643         public function getNsText() {
 644                 global $wgContLang;
 645
 646                 if ( $this->mInterwiki != '' ) {
 647                         // This probably shouldn't even happen. ohh man, oh yuck.
 648                         // But for interwiki transclusion it sometimes does.
 649                         // Shit. Shit shit shit.
 650                         //
 651                         // Use the canonical namespaces if possible to try to
 652                         // resolve a foreign namespace.
 653                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 654                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 655                         }
 656                 }
 657
 658                 // Strip off subpages
 659                 $pagename = $this->getText();
 660                 if ( strpos( $pagename, '/' ) !== false ) {
 661                         list( $username , ) = explode( '/', $pagename, 2 );
 662                 } else {
 663                         $username = $pagename;
 664                 }
 665
 666                 if ( $wgContLang->needsGenderDistinction() &&
 667                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 668                         $gender = GenderCache::singleton()->getGenderOf( $username, __METHOD__ );
 669                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 670                 }
 671
 672                 return $wgContLang->getNsText( $this->mNamespace );
 673         }
 674
 675         /**
 676          * Get the DB key with the initial letter case as specified by the user
 677          *
 678          * @return String DB key
 679          */
 680         function getUserCaseDBKey() {
 681                 return $this->mUserCaseDBKey;
 682         }
 683
 684         /**
 685          * Get the namespace text of the subject (rather than talk) page
 686          *
 687          * @return String Namespace text
 688          */
 689         public function getSubjectNsText() {
 690                 global $wgContLang;
 691                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 692         }
 693
 694         /**
 695          * Get the namespace text of the talk page
 696          *
 697          * @return String Namespace text
 698          */
 699         public function getTalkNsText() {
 700                 global $wgContLang;
 701                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 702         }
 703
 704         /**
 705          * Could this title have a corresponding talk page?
 706          *
 707          * @return Bool TRUE or FALSE
 708          */
 709         public function canTalk() {
 710                 return( MWNamespace::canTalk( $this->mNamespace ) );
 711         }
 712
 713         /**
 714          * Get the Title fragment (i.e.\ the bit after the #) in text form
 715          *
 716          * @return String Title fragment
 717          */
 718         public function getFragment() { return $this->mFragment; }
 719
 720         /**
 721          * Get the fragment in URL form, including the "#" character if there is one
 722          * @return String Fragment in URL form
 723          */
 724         public function getFragmentForURL() {
 725                 if ( $this->mFragment == '' ) {
 726                         return '';
 727                 } else {
 728                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 729                 }
 730         }
 731
 732         /**
 733          * Get the default namespace index, for when there is no namespace
 734          *
 735          * @return Int Default namespace index
 736          */
 737         public function getDefaultNamespace() {
 738                 return $this->mDefaultNamespace;
 739         }
 740
 741         /**
 742          * Get title for search index
 743          *
 744          * @return String a stripped-down title string ready for the
 745          *  search index
 746          */
 747         public function getIndexTitle() {
 748                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 749         }
 750
 751         /**
 752          * Get the prefixed database key form
 753          *
 754          * @return String the prefixed title, with underscores and
 755          *  any interwiki and namespace prefixes
 756          */
 757         public function getPrefixedDBkey() {
 758                 $s = $this->prefix( $this->mDbkeyform );
 759                 $s = str_replace( ' ', '_', $s );
 760                 return $s;
 761         }
 762
 763         /**
 764          * Get the prefixed title with spaces.
 765          * This is the form usually used for display
 766          *
 767          * @return String the prefixed title, with spaces
 768          */
 769         public function getPrefixedText() {
 770                 // @todo FIXME: Bad usage of empty() ?
 771                 if ( empty( $this->mPrefixedText ) ) {
 772                         $s = $this->prefix( $this->mTextform );
 773                         $s = str_replace( '_', ' ', $s );
 774                         $this->mPrefixedText = $s;
 775                 }
 776                 return $this->mPrefixedText;
 777         }
 778
 779         /**
 780         /**
 781          * Get the prefixed title with spaces, plus any fragment
 782          * (part beginning with '#')
 783          *
 784          * @return String the prefixed title, with spaces and the fragment, including '#'
 785          */
 786         public function getFullText() {
 787                 $text = $this->getPrefixedText();
 788                 if ( $this->mFragment != '' ) {
 789                         $text .= '#' . $this->mFragment;
 790                 }
 791                 return $text;
 792         }
 793
 794         /**
 795          * Get the base page name, i.e. the leftmost part before any slashes
 796          *
 797          * @return String Base name
 798          */
 799         public function getBaseText() {
 800                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 801                         return $this->getText();
 802                 }
 803
 804                 $parts = explode( '/', $this->getText() );
 805                 # Don't discard the real title if there's no subpage involved
 806                 if ( count( $parts ) > 1 ) {
 807                         unset( $parts[count( $parts ) - 1] );
 808                 }
 809                 return implode( '/', $parts );
 810         }
 811
 812         /**
 813          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
 814          *
 815          * @return String Subpage name
 816          */
 817         public function getSubpageText() {
 818                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 819                         return( $this->mTextform );
 820                 }
 821                 $parts = explode( '/', $this->mTextform );
 822                 return( $parts[count( $parts ) - 1] );
 823         }
 824
 825         /**
 826          * Get the HTML-escaped displayable text form.
 827          * Used for the title field in <a> tags.
 828          *
 829          * @return String the text, including any prefixes
 830          */
 831         public function getEscapedText() {
 832                 return htmlspecialchars( $this->getPrefixedText() );
 833         }
 834
 835         /**
 836          * Get a URL-encoded form of the subpage text
 837          *
 838          * @return String URL-encoded subpage name
 839          */
 840         public function getSubpageUrlForm() {
 841                 $text = $this->getSubpageText();
 842                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 843                 return( $text );
 844         }
 845
 846         /**
 847          * Get a URL-encoded title (not an actual URL) including interwiki
 848          *
 849          * @return String the URL-encoded form
 850          */
 851         public function getPrefixedURL() {
 852                 $s = $this->prefix( $this->mDbkeyform );
 853                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 854                 return $s;
 855         }
 856
 857         /**
 858          * Get a real URL referring to this title, with interwiki link and
 859          * fragment
 860          *
 861          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 862          *   links. Can be specified as an associative array as well, e.g.,
 863          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 864          * @param $variant String language variant of url (for sr, zh..)
 865          * @return String the URL
 866          */
 867         public function getFullURL( $query = '', $variant = false ) {
 868                 # Hand off all the decisions on urls to getLocalURL
 869                 $url = $this->getLocalURL( $query, $variant );
 870
 871                 # Expand the url to make it a full url. Note that getLocalURL has the
 872                 # potential to output full urls for a variety of reasons, so we use
 873                 # wfExpandUrl instead of simply prepending $wgServer
 874                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
 875
 876                 # Finally, add the fragment.
 877                 $url .= $this->getFragmentForURL();
 878
 879                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query, $variant ) );
 880                 return $url;
 881         }
 882
 883         /**
 884          * Get a URL with no fragment or server name.  If this page is generated
 885          * with action=render, $wgServer is prepended.
 886          *
 887          * @param $query Mixed: an optional query string; if not specified,
 888          *   $wgArticlePath will be used.  Can be specified as an associative array
 889          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 890          *   URL-escaped).
 891          * @param $variant String language variant of url (for sr, zh..)
 892          * @return String the URL
 893          */
 894         public function getLocalURL( $query = '', $variant = false ) {
 895                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 896                 global $wgVariantArticlePath;
 897
 898                 if ( is_array( $query ) ) {
 899                         $query = wfArrayToCGI( $query );
 900                 }
 901
 902                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 903                 if ( $interwiki ) {
 904                         $namespace = $this->getNsText();
 905                         if ( $namespace != '' ) {
 906                                 # Can this actually happen? Interwikis shouldn't be parsed.
 907                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 908                                 $namespace .= ':';
 909                         }
 910                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 911                         $url = wfAppendQuery( $url, $query );
 912                 } else {
 913                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 914                         if ( $query == '' ) {
 915                                 if ( $variant != false && $this->getPageLanguage()->hasVariants() ) {
 916                                         if ( !$wgVariantArticlePath ) {
 917                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 918                                         } else {
 919                                                 $variantArticlePath = $wgVariantArticlePath;
 920                                         }
 921                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 922                                         $url = str_replace( '$1', $dbkey, $url  );
 923                                 } else {
 924                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 925                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
 926                                 }
 927                         } else {
 928                                 global $wgActionPaths;
 929                                 $url = false;
 930                                 $matches = array();
 931                                 if ( !empty( $wgActionPaths ) &&
 932                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 933                                 {
 934                                         $action = urldecode( $matches[2] );
 935                                         if ( isset( $wgActionPaths[$action] ) ) {
 936                                                 $query = $matches[1];
 937                                                 if ( isset( $matches[4] ) ) {
 938                                                         $query .= $matches[4];
 939                                                 }
 940                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 941                                                 if ( $query != '' ) {
 942                                                         $url = wfAppendQuery( $url, $query );
 943                                                 }
 944                                         }
 945                                 }
 946
 947                                 if ( $url === false ) {
 948                                         if ( $query == '-' ) {
 949                                                 $query = '';
 950                                         }
 951                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 952                                 }
 953                         }
 954
 955                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
 956
 957                         // @todo FIXME: This causes breakage in various places when we
 958                         // actually expected a local URL and end up with dupe prefixes.
 959                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 960                                 $url = $wgServer . $url;
 961                         }
 962                 }
 963                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
 964                 return $url;
 965         }
 966
 967         /**
 968          * Get a URL that's the simplest URL that will be valid to link, locally,
 969          * to the current Title.  It includes the fragment, but does not include
 970          * the server unless action=render is used (or the link is external).  If
 971          * there's a fragment but the prefixed text is empty, we just return a link
 972          * to the fragment.
 973          *
 974          * The result obviously should not be URL-escaped, but does need to be
 975          * HTML-escaped if it's being output in HTML.
 976          *
 977          * @param $query Array of Strings An associative array of key => value pairs for the
 978          *   query string.  Keys and values will be escaped.
 979          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 980          *   for external links.  Default is "false" (same variant as current page,
 981          *   for anonymous users).
 982          * @return String the URL
 983          */
 984         public function getLinkURL( $query = array(), $variant = false ) {
 985                 wfProfileIn( __METHOD__ );
 986                 if ( $this->isExternal() ) {
 987                         $ret = $this->getFullURL( $query );
 988                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 989                         $ret = $this->getFragmentForURL();
 990                 } else {
 991                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 992                 }
 993                 wfProfileOut( __METHOD__ );
 994                 return $ret;
 995         }
 996
 997         /**
 998          * Get an HTML-escaped version of the URL form, suitable for
 999          * using in a link, without a server name or fragment
1000          *
1001          * @param $query String an optional query string
1002          * @return String the URL
1003          */
1004         public function escapeLocalURL( $query = '' ) {
1005                 return htmlspecialchars( $this->getLocalURL( $query ) );
1006         }
1007
1008         /**
1009          * Get an HTML-escaped version of the URL form, suitable for
1010          * using in a link, including the server name and fragment
1011          *
1012          * @param $query String an optional query string
1013          * @return String the URL
1014          */
1015         public function escapeFullURL( $query = '' ) {
1016                 return htmlspecialchars( $this->getFullURL( $query ) );
1017         }
1018
1019         /**
1020          * Get the URL form for an internal link.
1021          * - Used in various Squid-related code, in case we have a different
1022          * internal hostname for the server from the exposed one.
1023          *
1024          * This uses $wgInternalServer to qualify the path, or $wgServer
1025          * if $wgInternalServer is not set. If the server variable used is
1026          * protocol-relative, the URL will be expanded to http://
1027          *
1028          * @param $query String an optional query string
1029          * @param $variant String language variant of url (for sr, zh..)
1030          * @return String the URL
1031          */
1032         public function getInternalURL( $query = '', $variant = false ) {
1033                 global $wgInternalServer, $wgServer;
1034                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1035                 $url = wfExpandUrl( $server . $this->getLocalURL( $query, $variant ), PROTO_HTTP );
1036                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query, $variant ) );
1037                 return $url;
1038         }
1039
1040         /**
1041          * Get the URL for a canonical link, for use in things like IRC and
1042          * e-mail notifications. Uses $wgCanonicalServer and the
1043          * GetCanonicalURL hook.
1044          *
1045          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1046          *
1047          * @param $query string An optional query string
1048          * @param $variant string Language variant of URL (for sr, zh, ...)
1049          * @return string The URL
1050          * @since 1.18
1051          */
1052         public function getCanonicalURL( $query = '', $variant = false ) {
1053                 $url = wfExpandUrl( $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1054                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query, $variant ) );
1055                 return $url;
1056         }
1057
1058         /**
1059          * HTML-escaped version of getCanonicalURL()
1060          * @since 1.18
1061          */
1062         public function escapeCanonicalURL( $query = '', $variant = false ) {
1063                 return htmlspecialchars( $this->getCanonicalURL( $query, $variant ) );
1064         }
1065
1066         /**
1067          * Get the edit URL for this Title
1068          *
1069          * @return String the URL, or a null string if this is an
1070          *  interwiki link
1071          */
1072         public function getEditURL() {
1073                 if ( $this->mInterwiki != '' ) {
1074                         return '';
1075                 }
1076                 $s = $this->getLocalURL( 'action=edit' );
1077
1078                 return $s;
1079         }
1080
1081         /**
1082          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1083          *
1084          * @param $action String Action to check (default: edit)
1085          * @return Bool
1086          */
1087         public function isSemiProtected( $action = 'edit' ) {
1088                 if ( $this->exists() ) {
1089                         $restrictions = $this->getRestrictions( $action );
1090                         if ( count( $restrictions ) > 0 ) {
1091                                 foreach ( $restrictions as $restriction ) {
1092                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1093                                                 return false;
1094                                         }
1095                                 }
1096                         } else {
1097                                 # Not protected
1098                                 return false;
1099                         }
1100                         return true;
1101                 } else {
1102                         # If it doesn't exist, it can't be protected
1103                         return false;
1104                 }
1105         }
1106
1107         /**
1108          * Does the title correspond to a protected article?
1109          *
1110          * @param $action String the action the page is protected from,
1111          * by default checks all actions.
1112          * @return Bool
1113          */
1114         public function isProtected( $action = '' ) {
1115                 global $wgRestrictionLevels;
1116
1117                 $restrictionTypes = $this->getRestrictionTypes();
1118
1119                 # Special pages have inherent protection
1120                 if( $this->isSpecialPage() ) {
1121                         return true;
1122                 }
1123
1124                 # Check regular protection levels
1125                 foreach ( $restrictionTypes as $type ) {
1126                         if ( $action == $type || $action == '' ) {
1127                                 $r = $this->getRestrictions( $type );
1128                                 foreach ( $wgRestrictionLevels as $level ) {
1129                                         if ( in_array( $level, $r ) && $level != '' ) {
1130                                                 return true;
1131                                         }
1132                                 }
1133                         }
1134                 }
1135
1136                 return false;
1137         }
1138
1139         /**
1140          * Determines if $user is unable to edit this page because it has been protected
1141          * by $wgNamespaceProtection.
1142          *
1143          * @param $user User object to check permissions
1144          * @return Bool
1145          */
1146         public function isNamespaceProtected( User $user ) {
1147                 global $wgNamespaceProtection;
1148
1149                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1150                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1151                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1152                                         return true;
1153                                 }
1154                         }
1155                 }
1156                 return false;
1157         }
1158
1159         /**
1160          * Is this a conversion table for the LanguageConverter?
1161          *
1162          * @return Bool
1163          */
1164         public function isConversionTable() {
1165                 if(
1166                         $this->getNamespace() == NS_MEDIAWIKI &&
1167                         strpos( $this->getText(), 'Conversiontable' ) !== false
1168                 )
1169                 {
1170                         return true;
1171                 }
1172
1173                 return false;
1174         }
1175
1176         /**
1177          * Is $wgUser watching this page?
1178          *
1179          * @return Bool
1180          */
1181         public function userIsWatching() {
1182                 global $wgUser;
1183
1184                 if ( is_null( $this->mWatched ) ) {
1185                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1186                                 $this->mWatched = false;
1187                         } else {
1188                                 $this->mWatched = $wgUser->isWatched( $this );
1189                         }
1190                 }
1191                 return $this->mWatched;
1192         }
1193
1194         /**
1195          * Can $wgUser read this page?
1196          *
1197          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1198          * @return Bool
1199          * @todo fold these checks into userCan()
1200          */
1201         public function userCanRead() {
1202                 return $this->userCan( 'read' );
1203         }
1204
1205         /**
1206          * Can $wgUser perform $action on this page?
1207          * This skips potentially expensive cascading permission checks
1208          * as well as avoids expensive error formatting
1209          *
1210          * Suitable for use for nonessential UI controls in common cases, but
1211          * _not_ for functional access control.
1212          *
1213          * May provide false positives, but should never provide a false negative.
1214          *
1215          * @param $action String action that permission needs to be checked for
1216          * @param $user User to check (since 1.19)
1217          * @return Bool
1218          */
1219         public function quickUserCan( $action, $user = null ) {
1220                 return $this->userCan( $action, $user, false );
1221         }
1222
1223         /**
1224          * Can $wgUser perform $action on this page?
1225          *
1226          * @param $action String action that permission needs to be checked for
1227          * @param $user User to check (since 1.19)
1228          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1229          * @return Bool
1230          */
1231         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1232                 if ( !$user instanceof User ) {
1233                         global $wgUser;
1234                         $user = $wgUser;
1235                 }
1236                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1237         }
1238
1239         /**
1240          * Can $user perform $action on this page?
1241          *
1242          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1243          *
1244          * @param $action String action that permission needs to be checked for
1245          * @param $user User to check
1246          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1247          *   skipping checks for cascading protections and user blocks.
1248          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1249          * @return Array of arguments to wfMsg to explain permissions problems.
1250          */
1251         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1252                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1253
1254                 // Remove the errors being ignored.
1255                 foreach ( $errors as $index => $error ) {
1256                         $error_key = is_array( $error ) ? $error[0] : $error;
1257
1258                         if ( in_array( $error_key, $ignoreErrors ) ) {
1259                                 unset( $errors[$index] );
1260                         }
1261                 }
1262
1263                 return $errors;
1264         }
1265
1266         /**
1267          * Permissions checks that fail most often, and which are easiest to test.
1268          *
1269          * @param $action String the action to check
1270          * @param $user User user to check
1271          * @param $errors Array list of current errors
1272          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1273          * @param $short Boolean short circuit on first error
1274          *
1275          * @return Array list of errors
1276          */
1277         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1278                 $ns = $this->getNamespace();
1279
1280                 if ( $action == 'create' ) {
1281                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1282                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1283                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1284                         }
1285                 } elseif ( $action == 'move' ) {
1286                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1287                                         && $ns == NS_USER && !$this->isSubpage() ) {
1288                                 // Show user page-specific message only if the user can move other pages
1289                                 $errors[] = array( 'cant-move-user-page' );
1290                         }
1291
1292                         // Check if user is allowed to move files if it's a file
1293                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1294                                 $errors[] = array( 'movenotallowedfile' );
1295                         }
1296
1297                         if ( !$user->isAllowed( 'move', $ns) ) {
1298                                 // User can't move anything
1299
1300                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1301                                         array( 'user' ), $ns ), true );
1302                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1303                                         array( 'autoconfirmed' ), $ns ), true );
1304
1305                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1306                                         // custom message if logged-in users without any special rights can move
1307                                         $errors[] = array( 'movenologintext' );
1308                                 } else {
1309                                         $errors[] = array( 'movenotallowed' );
1310                                 }
1311                         }
1312                 } elseif ( $action == 'move-target' ) {
1313                         if ( !$user->isAllowed( 'move', $ns ) ) {
1314                                 // User can't move anything
1315                                 $errors[] = array( 'movenotallowed' );
1316                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1317                                         && $ns == NS_USER && !$this->isSubpage() ) {
1318                                 // Show user page-specific message only if the user can move other pages
1319                                 $errors[] = array( 'cant-move-to-user-page' );
1320                         }
1321                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1322                         $errors[] = $this->missingPermissionError( $action, $short );
1323                 }
1324
1325                 return $errors;
1326         }
1327
1328         /**
1329          * Add the resulting error code to the errors array
1330          *
1331          * @param $errors Array list of current errors
1332          * @param $result Mixed result of errors
1333          *
1334          * @return Array list of errors
1335          */
1336         private function resultToError( $errors, $result ) {
1337                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1338                         // A single array representing an error
1339                         $errors[] = $result;
1340                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1341                         // A nested array representing multiple errors
1342                         $errors = array_merge( $errors, $result );
1343                 } elseif ( $result !== '' && is_string( $result ) ) {
1344                         // A string representing a message-id
1345                         $errors[] = array( $result );
1346                 } elseif ( $result === false ) {
1347                         // a generic "We don't want them to do that"
1348                         $errors[] = array( 'badaccess-group0' );
1349                 }
1350                 return $errors;
1351         }
1352
1353         /**
1354          * Check various permission hooks
1355          *
1356          * @param $action String the action to check
1357          * @param $user User user to check
1358          * @param $errors Array list of current errors
1359          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1360          * @param $short Boolean short circuit on first error
1361          *
1362          * @return Array list of errors
1363          */
1364         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1365                 // Use getUserPermissionsErrors instead
1366                 $result = '';
1367                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1368                         return $result ? array() : array( array( 'badaccess-group0' ) );
1369                 }
1370                 // Check getUserPermissionsErrors hook
1371                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1372                         $errors = $this->resultToError( $errors, $result );
1373                 }
1374                 // Check getUserPermissionsErrorsExpensive hook
1375                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1376                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1377                         $errors = $this->resultToError( $errors, $result );
1378                 }
1379
1380                 return $errors;
1381         }
1382
1383         /**
1384          * Check permissions on special pages & namespaces
1385          *
1386          * @param $action String the action to check
1387          * @param $user User user to check
1388          * @param $errors Array list of current errors
1389          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1390          * @param $short Boolean short circuit on first error
1391          *
1392          * @return Array list of errors
1393          */
1394         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1395                 # Only 'createaccount' and 'execute' can be performed on
1396                 # special pages, which don't actually exist in the DB.
1397                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1398                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1399                         $errors[] = array( 'ns-specialprotected' );
1400                 }
1401
1402                 # Check $wgNamespaceProtection for restricted namespaces
1403                 if ( $this->isNamespaceProtected( $user ) ) {
1404                         $ns = $this->mNamespace == NS_MAIN ?
1405                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1406                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1407                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1408                 }
1409
1410                 return $errors;
1411         }
1412
1413         /**
1414          * Check CSS/JS sub-page permissions
1415          *
1416          * @param $action String the action to check
1417          * @param $user User user to check
1418          * @param $errors Array list of current errors
1419          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1420          * @param $short Boolean short circuit on first error
1421          *
1422          * @return Array list of errors
1423          */
1424         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1425                 # Protect css/js subpages of user pages
1426                 # XXX: this might be better using restrictions
1427                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1428                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1429                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1430                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1431                                 $errors[] = array( 'customcssprotected' );
1432                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1433                                 $errors[] = array( 'customjsprotected' );
1434                         }
1435                 }
1436
1437                 return $errors;
1438         }
1439
1440         /**
1441          * Check against page_restrictions table requirements on this
1442          * page. The user must possess all required rights for this
1443          * action.
1444          *
1445          * @param $action String the action to check
1446          * @param $user User user to check
1447          * @param $errors Array list of current errors
1448          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1449          * @param $short Boolean short circuit on first error
1450          *
1451          * @return Array list of errors
1452          */
1453         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1454                 foreach ( $this->getRestrictions( $action ) as $right ) {
1455                         // Backwards compatibility, rewrite sysop -> protect
1456                         if ( $right == 'sysop' ) {
1457                                 $right = 'protect';
1458                         }
1459                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1460                                 // Users with 'editprotected' permission can edit protected pages
1461                                 // without cascading option turned on.
1462                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected', $this->mNamespace )
1463                                         || $this->mCascadeRestriction )
1464                                 {
1465                                         $errors[] = array( 'protectedpagetext', $right );
1466                                 }
1467                         }
1468                 }
1469
1470                 return $errors;
1471         }
1472
1473         /**
1474          * Check restrictions on cascading pages.
1475          *
1476          * @param $action String the action to check
1477          * @param $user User to check
1478          * @param $errors Array list of current errors
1479          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1480          * @param $short Boolean short circuit on first error
1481          *
1482          * @return Array list of errors
1483          */
1484         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1485                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1486                         # We /could/ use the protection level on the source page, but it's
1487                         # fairly ugly as we have to establish a precedence hierarchy for pages
1488                         # included by multiple cascade-protected pages. So just restrict
1489                         # it to people with 'protect' permission, as they could remove the
1490                         # protection anyway.
1491                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1492                         # Cascading protection depends on more than this page...
1493                         # Several cascading protected pages may include this page...
1494                         # Check each cascading level
1495                         # This is only for protection restrictions, not for all actions
1496                         if ( isset( $restrictions[$action] ) ) {
1497                                 foreach ( $restrictions[$action] as $right ) {
1498                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1499                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1500                                                 $pages = '';
1501                                                 foreach ( $cascadingSources as $page )
1502                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1503                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1504                                         }
1505                                 }
1506                         }
1507                 }
1508
1509                 return $errors;
1510         }
1511
1512         /**
1513          * Check action permissions not already checked in checkQuickPermissions
1514          *
1515          * @param $action String the action to check
1516          * @param $user User to check
1517          * @param $errors Array list of current errors
1518          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1519          * @param $short Boolean short circuit on first error
1520          *
1521          * @return Array list of errors
1522          */
1523         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1524                 if ( $action == 'protect' ) {
1525                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1526                                 // If they can't edit, they shouldn't protect.
1527                                 $errors[] = array( 'protect-cantedit' );
1528                         }
1529                 } elseif ( $action == 'create' ) {
1530                         $title_protection = $this->getTitleProtection();
1531                         if( $title_protection ) {
1532                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1533                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1534                                 }
1535                                 if( $title_protection['pt_create_perm'] == '' ||
1536                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1537                                                 $this->mNamespace ) ) {
1538                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1539                                 }
1540                         }
1541                 } elseif ( $action == 'move' ) {
1542                         // Check for immobile pages
1543                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1544                                 // Specific message for this case
1545                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1546                         } elseif ( !$this->isMovable() ) {
1547                                 // Less specific message for rarer cases
1548                                 $errors[] = array( 'immobile-source-page' );
1549                         }
1550                 } elseif ( $action == 'move-target' ) {
1551                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1552                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1553                         } elseif ( !$this->isMovable() ) {
1554                                 $errors[] = array( 'immobile-target-page' );
1555                         }
1556                 }
1557                 return $errors;
1558         }
1559
1560         /**
1561          * Check that the user isn't blocked from editting.
1562          *
1563          * @param $action String the action to check
1564          * @param $user User to check
1565          * @param $errors Array list of current errors
1566          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1567          * @param $short Boolean short circuit on first error
1568          *
1569          * @return Array list of errors
1570          */
1571         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1572                 // Account creation blocks handled at userlogin.
1573                 // Unblocking handled in SpecialUnblock
1574                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1575                         return $errors;
1576                 }
1577
1578                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1579
1580                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1581                         $errors[] = array( 'confirmedittext' );
1582                 }
1583
1584                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1585                         // Don't block the user from editing their own talk page unless they've been
1586                         // explicitly blocked from that too.
1587                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1588                         $block = $user->mBlock;
1589
1590                         // This is from OutputPage::blockedPage
1591                         // Copied at r23888 by werdna
1592
1593                         $id = $user->blockedBy();
1594                         $reason = $user->blockedFor();
1595                         if ( $reason == '' ) {
1596                                 $reason = wfMsg( 'blockednoreason' );
1597                         }
1598                         $ip = $user->getRequest()->getIP();
1599
1600                         if ( is_numeric( $id ) ) {
1601                                 $name = User::whoIs( $id );
1602                         } else {
1603                                 $name = $id;
1604                         }
1605
1606                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1607                         $blockid = $block->getId();
1608                         $blockExpiry = $user->mBlock->mExpiry;
1609                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1610                         if ( $blockExpiry == 'infinity' ) {
1611                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1612                         } else {
1613                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1614                         }
1615
1616                         $intended = strval( $user->mBlock->getTarget() );
1617
1618                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1619                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1620                 }
1621
1622                 return $errors;
1623         }
1624
1625         /**
1626          * Check that the user is allowed to read this page.
1627          *
1628          * @param $action String the action to check
1629          * @param $user User to check
1630          * @param $errors Array list of current errors
1631          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1632          * @param $short Boolean short circuit on first error
1633          *
1634          * @return Array list of errors
1635          */
1636         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1637                 static $useShortcut = null;
1638
1639                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1640                 if ( is_null( $useShortcut ) ) {
1641                         global $wgGroupPermissions, $wgRevokePermissions;
1642                         $useShortcut = true;
1643                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1644                                 # Not a public wiki, so no shortcut
1645                                 $useShortcut = false;
1646                         } elseif ( !empty( $wgRevokePermissions ) ) {
1647                                 /**
1648                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1649                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1650                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1651                                  * reading is allowed.
1652                                  */
1653                                 foreach ( $wgRevokePermissions as $perms ) {
1654                                         if ( !empty( $perms['read'] ) ) {
1655                                                 # We might be removing the read right from the user, so no shortcut
1656                                                 $useShortcut = false;
1657                                                 break;
1658                                         }
1659                                 }
1660                         }
1661                 }
1662
1663                 # Shortcut for public wikis, allows skipping quite a bit of code
1664                 if ( $useShortcut ) {
1665                         return $errors;
1666                 }
1667
1668                 # If the user is allowed to read pages, he is allowed to read all pages
1669                 if ( $user->isAllowed( 'read', $this->mNamespace ) ) {
1670                         return $errors;
1671                 }
1672
1673                 # Always grant access to the login page.
1674                 # Even anons need to be able to log in.
1675                 if ( $this->isSpecial( 'Userlogin' )
1676                         || $this->isSpecial( 'ChangePassword' )
1677                         || $this->isSpecial( 'PasswordReset' )
1678                 ) {
1679                         return $errors;
1680                 }
1681
1682                 # Time to check the whitelist
1683                 global $wgWhitelistRead;
1684
1685                 # Only to these checks is there's something to check against
1686                 if ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
1687                         # Check for explicit whitelisting
1688                         $name = $this->getPrefixedText();
1689                         $dbName = $this->getPrefixedDBKey();
1690
1691                         // Check with and without underscores
1692                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
1693                                 return $errors;
1694                         }
1695
1696                         # Old settings might have the title prefixed with
1697                         # a colon for main-namespace pages
1698                         if ( $this->getNamespace() == NS_MAIN ) {
1699                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1700                                         return $errors;
1701                                 }
1702                         }
1703
1704                         # If it's a special page, ditch the subpage bit and check again
1705                         if ( $this->isSpecialPage() ) {
1706                                 $name = $this->getDBkey();
1707                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1708                                 if ( $name !== false ) {
1709                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1710                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1711                                                 return $errors;
1712                                         }
1713                                 }
1714                         }
1715                 }
1716
1717                 $errors[] = $this->missingPermissionError( $action, $short );
1718                 return $errors;
1719         }
1720
1721         /**
1722          * Get a description array when the user doesn't have the right to perform
1723          * $action (i.e. when User::isAllowed() returns false)
1724          *
1725          * @param $action String the action to check
1726          * @param $short Boolean short circuit on first error
1727          * @return Array list of errors
1728          */
1729         private function missingPermissionError( $action, $short ) {
1730                 // We avoid expensive display logic for quickUserCan's and such
1731                 if ( $short ) {
1732                         return array( 'badaccess-group0' );
1733                 }
1734
1735                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1736                         User::getGroupsWithPermission( $action, $this->mNamespace ) );
1737
1738                 if ( count( $groups ) ) {
1739                         global $wgLang;
1740                         return array(
1741                                 'badaccess-groups',
1742                                 $wgLang->commaList( $groups ),
1743                                 count( $groups )
1744                         );
1745                 } else {
1746                         return array( 'badaccess-group0' );
1747                 }
1748         }
1749
1750         /**
1751          * Can $user perform $action on this page? This is an internal function,
1752          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1753          * checks on wfReadOnly() and blocks)
1754          *
1755          * @param $action String action that permission needs to be checked for
1756          * @param $user User to check
1757          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1758          * @param $short Bool Set this to true to stop after the first permission error.
1759          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1760          */
1761         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1762                 wfProfileIn( __METHOD__ );
1763
1764                 # Read has special handling
1765                 if ( $action == 'read' ) {
1766                         $checks = array(
1767                                 'checkPermissionHooks',
1768                                 'checkReadPermissions',
1769                         );
1770                 } else {
1771                         $checks = array(
1772                                 'checkQuickPermissions',
1773                                 'checkPermissionHooks',
1774                                 'checkSpecialsAndNSPermissions',
1775                                 'checkCSSandJSPermissions',
1776                                 'checkPageRestrictions',
1777                                 'checkCascadingSourcesRestrictions',
1778                                 'checkActionPermissions',
1779                                 'checkUserBlock'
1780                         );
1781                 }
1782
1783                 $errors = array();
1784                 while( count( $checks ) > 0 &&
1785                                 !( $short && count( $errors ) > 0 ) ) {
1786                         $method = array_shift( $checks );
1787                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1788                 }
1789
1790                 wfProfileOut( __METHOD__ );
1791                 return $errors;
1792         }
1793
1794         /**
1795          * Is this title subject to title protection?
1796          * Title protection is the one applied against creation of such title.
1797          *
1798          * @return Mixed An associative array representing any existent title
1799          *   protection, or false if there's none.
1800          */
1801         private function getTitleProtection() {
1802                 // Can't protect pages in special namespaces
1803                 if ( $this->getNamespace() < 0 ) {
1804                         return false;
1805                 }
1806
1807                 // Can't protect pages that exist.
1808                 if ( $this->exists() ) {
1809                         return false;
1810                 }
1811
1812                 if ( !isset( $this->mTitleProtection ) ) {
1813                         $dbr = wfGetDB( DB_SLAVE );
1814                         $res = $dbr->select( 'protected_titles', '*',
1815                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1816                                 __METHOD__ );
1817
1818                         // fetchRow returns false if there are no rows.
1819                         $this->mTitleProtection = $dbr->fetchRow( $res );
1820                 }
1821                 return $this->mTitleProtection;
1822         }
1823
1824         /**
1825          * Update the title protection status
1826          *
1827          * @param $create_perm String Permission required for creation
1828          * @param $reason String Reason for protection
1829          * @param $expiry String Expiry timestamp
1830          * @return boolean true
1831          */
1832         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1833                 global $wgUser, $wgContLang;
1834
1835                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1836                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1837                         // No change
1838                         return true;
1839                 }
1840
1841                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1842
1843                 $dbw = wfGetDB( DB_MASTER );
1844
1845                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1846
1847                 $expiry_description = '';
1848                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1849                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1850                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1851                 } else {
1852                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1853                 }
1854
1855                 # Update protection table
1856                 if ( $create_perm != '' ) {
1857                         $this->mTitleProtection = array(
1858                                         'pt_namespace' => $namespace,
1859                                         'pt_title' => $title,
1860                                         'pt_create_perm' => $create_perm,
1861                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1862                                         'pt_expiry' => $encodedExpiry,
1863                                         'pt_user' => $wgUser->getId(),
1864                                         'pt_reason' => $reason,
1865                                 );
1866                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1867                                 $this->mTitleProtection, __METHOD__     );
1868                 } else {
1869                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1870                                 'pt_title' => $title ), __METHOD__ );
1871                         $this->mTitleProtection = false;
1872                 }
1873
1874                 # Update the protection log
1875                 if ( $dbw->affectedRows() ) {
1876                         $log = new LogPage( 'protect' );
1877
1878                         if ( $create_perm ) {
1879                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1880                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1881                         } else {
1882                                 $log->addEntry( 'unprotect', $this, $reason );
1883                         }
1884                 }
1885
1886                 return true;
1887         }
1888
1889         /**
1890          * Remove any title protection due to page existing
1891          */
1892         public function deleteTitleProtection() {
1893                 $dbw = wfGetDB( DB_MASTER );
1894
1895                 $dbw->delete(
1896                         'protected_titles',
1897                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1898                         __METHOD__
1899                 );
1900                 $this->mTitleProtection = false;
1901         }
1902
1903         /**
1904          * Would anybody with sufficient privileges be able to move this page?
1905          * Some pages just aren't movable.
1906          *
1907          * @return Bool TRUE or FALSE
1908          */
1909         public function isMovable() {
1910                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
1911                         // Interwiki title or immovable namespace. Hooks don't get to override here
1912                         return false;
1913                 }
1914
1915                 $result = true;
1916                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1917                 return $result;
1918         }
1919
1920         /**
1921          * Is this the mainpage?
1922          * @note Title::newFromText seams to be sufficiently optimized by the title
1923          * cache that we don't need to over-optimize by doing direct comparisons and
1924          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1925          * ends up reporting something differently than $title->isMainPage();
1926          *
1927          * @since 1.18
1928          * @return Bool
1929          */
1930         public function isMainPage() {
1931                 return $this->equals( Title::newMainPage() );
1932         }
1933
1934         /**
1935          * Is this a talk page of some sort?
1936          *
1937          * @return Bool
1938          */
1939         public function isTalkPage() {
1940                 return MWNamespace::isTalk( $this->getNamespace() );
1941         }
1942
1943         /**
1944          * Is this a subpage?
1945          *
1946          * @return Bool
1947          */
1948         public function isSubpage() {
1949                 return MWNamespace::hasSubpages( $this->mNamespace )
1950                         ? strpos( $this->getText(), '/' ) !== false
1951                         : false;
1952         }
1953
1954         /**
1955          * Returns true if the title is inside the specified namespace.
1956          *
1957          * Please make use of this instead of comparing to getNamespace()
1958          * This function is much more resistant to changes we may make
1959          * to namespaces than code that makes direct comparisons.
1960          * @param $ns int The namespace
1961          * @return bool
1962          * @since 1.19
1963          */
1964         public function inNamespace( $ns ) {
1965                 return MWNamespace::equals( $this->getNamespace(), $ns );
1966         }
1967
1968         /**
1969          * Returns true if the title is inside one of the specified namespaces.
1970          *
1971          * @param ...$namespaces The namespaces to check for
1972          * @return bool
1973          * @since 1.19
1974          */
1975         public function inNamespaces( /* ... */ ) {
1976                 $namespaces = func_get_args();
1977                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1978                         $namespaces = $namespaces[0];
1979                 }
1980
1981                 foreach ( $namespaces as $ns ) {
1982                         if ( $this->inNamespace( $ns ) ) {
1983                                 return true;
1984                         }
1985                 }
1986
1987                 return false;
1988         }
1989
1990         /**
1991          * Returns true if the title has the same subject namespace as the
1992          * namespace specified.
1993          * For example this method will take NS_USER and return true if namespace
1994          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1995          * as their subject namespace.
1996          *
1997          * This is MUCH simpler than individually testing for equivilance
1998          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1999          * @since 1.19
2000          */
2001         public function hasSubjectNamespace( $ns ) {
2002                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
2003         }
2004
2005         /**
2006          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2007          *
2008          * @return Bool
2009          */
2010         public function hasSubpages() {
2011                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2012                         # Duh
2013                         return false;
2014                 }
2015
2016                 # We dynamically add a member variable for the purpose of this method
2017                 # alone to cache the result.  There's no point in having it hanging
2018                 # around uninitialized in every Title object; therefore we only add it
2019                 # if needed and don't declare it statically.
2020                 if ( isset( $this->mHasSubpages ) ) {
2021                         return $this->mHasSubpages;
2022                 }
2023
2024                 $subpages = $this->getSubpages( 1 );
2025                 if ( $subpages instanceof TitleArray ) {
2026                         return $this->mHasSubpages = (bool)$subpages->count();
2027                 }
2028                 return $this->mHasSubpages = false;
2029         }
2030
2031         /**
2032          * Get all subpages of this page.
2033          *
2034          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2035          * @return mixed TitleArray, or empty array if this page's namespace
2036          *  doesn't allow subpages
2037          */
2038         public function getSubpages( $limit = -1 ) {
2039                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2040                         return array();
2041                 }
2042
2043                 $dbr = wfGetDB( DB_SLAVE );
2044                 $conds['page_namespace'] = $this->getNamespace();
2045                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2046                 $options = array();
2047                 if ( $limit > -1 ) {
2048                         $options['LIMIT'] = $limit;
2049                 }
2050                 return $this->mSubpages = TitleArray::newFromResult(
2051                         $dbr->select( 'page',
2052                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2053                                 $conds,
2054                                 __METHOD__,
2055                                 $options
2056                         )
2057                 );
2058         }
2059
2060         /**
2061          * Does that page contain wikitext, or it is JS, CSS or whatever?
2062          *
2063          * @return Bool
2064          */
2065         public function isWikitextPage() {
2066                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
2067                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
2068                 return $retval;
2069         }
2070
2071         /**
2072          * Could this page contain custom CSS or JavaScript, based
2073          * on the title?
2074          *
2075          * @return Bool
2076          */
2077         public function isCssOrJsPage() {
2078                 $retval = $this->mNamespace == NS_MEDIAWIKI
2079                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
2080                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
2081                 return $retval;
2082         }
2083
2084         /**
2085          * Is this a .css or .js subpage of a user page?
2086          * @return Bool
2087          */
2088         public function isCssJsSubpage() {
2089                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
2090         }
2091
2092         /**
2093          * Is this a *valid* .css or .js subpage of a user page?
2094          *
2095          * @return Bool
2096          * @deprecated since 1.17
2097          */
2098         public function isValidCssJsSubpage() {
2099                 return $this->isCssJsSubpage();
2100         }
2101
2102         /**
2103          * Trim down a .css or .js subpage title to get the corresponding skin name
2104          *
2105          * @return string containing skin name from .css or .js subpage title
2106          */
2107         public function getSkinFromCssJsSubpage() {
2108                 $subpage = explode( '/', $this->mTextform );
2109                 $subpage = $subpage[ count( $subpage ) - 1 ];
2110                 $lastdot = strrpos( $subpage, '.' );
2111                 if ( $lastdot === false )
2112                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
2113                 return substr( $subpage, 0, $lastdot );
2114         }
2115
2116         /**
2117          * Is this a .css subpage of a user page?
2118          *
2119          * @return Bool
2120          */
2121         public function isCssSubpage() {
2122                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2123         }
2124
2125         /**
2126          * Is this a .js subpage of a user page?
2127          *
2128          * @return Bool
2129          */
2130         public function isJsSubpage() {
2131                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2132         }
2133
2134         /**
2135          * Protect css subpages of user pages: can $wgUser edit
2136          * this page?
2137          *
2138          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2139          * @return Bool
2140          */
2141         public function userCanEditCssSubpage() {
2142                 global $wgUser;
2143                 wfDeprecated( __METHOD__ );
2144                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2145                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2146         }
2147
2148         /**
2149          * Protect js subpages of user pages: can $wgUser edit
2150          * this page?
2151          *
2152          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2153          * @return Bool
2154          */
2155         public function userCanEditJsSubpage() {
2156                 global $wgUser;
2157                 wfDeprecated( __METHOD__ );
2158                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2159                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2160         }
2161
2162         /**
2163          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2164          *
2165          * @return Bool If the page is subject to cascading restrictions.
2166          */
2167         public function isCascadeProtected() {
2168                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2169                 return ( $sources > 0 );
2170         }
2171
2172         /**
2173          * Cascading protection: Get the source of any cascading restrictions on this page.
2174          *
2175          * @param $getPages Bool Whether or not to retrieve the actual pages
2176          *        that the restrictions have come from.
2177          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2178          *     have come, false for none, or true if such restrictions exist, but $getPages
2179          *     was not set.  The restriction array is an array of each type, each of which
2180          *     contains a array of unique groups.
2181          */
2182         public function getCascadeProtectionSources( $getPages = true ) {
2183                 global $wgContLang;
2184                 $pagerestrictions = array();
2185
2186                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2187                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2188                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2189                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2190                 }
2191
2192                 wfProfileIn( __METHOD__ );
2193
2194                 $dbr = wfGetDB( DB_SLAVE );
2195
2196                 if ( $this->getNamespace() == NS_FILE ) {
2197                         $tables = array( 'imagelinks', 'page_restrictions' );
2198                         $where_clauses = array(
2199                                 'il_to' => $this->getDBkey(),
2200                                 'il_from=pr_page',
2201                                 'pr_cascade' => 1
2202                         );
2203                 } else {
2204                         $tables = array( 'templatelinks', 'page_restrictions' );
2205                         $where_clauses = array(
2206                                 'tl_namespace' => $this->getNamespace(),
2207                                 'tl_title' => $this->getDBkey(),
2208                                 'tl_from=pr_page',
2209                                 'pr_cascade' => 1
2210                         );
2211                 }
2212
2213                 if ( $getPages ) {
2214                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2215                                                    'pr_expiry', 'pr_type', 'pr_level' );
2216                         $where_clauses[] = 'page_id=pr_page';
2217                         $tables[] = 'page';
2218                 } else {
2219                         $cols = array( 'pr_expiry' );
2220                 }
2221
2222                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2223
2224                 $sources = $getPages ? array() : false;
2225                 $now = wfTimestampNow();
2226                 $purgeExpired = false;
2227
2228                 foreach ( $res as $row ) {
2229                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2230                         if ( $expiry > $now ) {
2231                                 if ( $getPages ) {
2232                                         $page_id = $row->pr_page;
2233                                         $page_ns = $row->page_namespace;
2234                                         $page_title = $row->page_title;
2235                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2236                                         # Add groups needed for each restriction type if its not already there
2237                                         # Make sure this restriction type still exists
2238
2239                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2240                                                 $pagerestrictions[$row->pr_type] = array();
2241                                         }
2242
2243                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2244                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2245                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2246                                         }
2247                                 } else {
2248                                         $sources = true;
2249                                 }
2250                         } else {
2251                                 // Trigger lazy purge of expired restrictions from the db
2252                                 $purgeExpired = true;
2253                         }
2254                 }
2255                 if ( $purgeExpired ) {
2256                         Title::purgeExpiredRestrictions();
2257                 }
2258
2259                 if ( $getPages ) {
2260                         $this->mCascadeSources = $sources;
2261                         $this->mCascadingRestrictions = $pagerestrictions;
2262                 } else {
2263                         $this->mHasCascadingRestrictions = $sources;
2264                 }
2265
2266                 wfProfileOut( __METHOD__ );
2267                 return array( $sources, $pagerestrictions );
2268         }
2269
2270         /**
2271          * Returns cascading restrictions for the current article
2272          *
2273          * @return Boolean
2274          */
2275         function areRestrictionsCascading() {
2276                 if ( !$this->mRestrictionsLoaded ) {
2277                         $this->loadRestrictions();
2278                 }
2279
2280                 return $this->mCascadeRestriction;
2281         }
2282
2283         /**
2284          * Loads a string into mRestrictions array
2285          *
2286          * @param $res Resource restrictions as an SQL result.
2287          * @param $oldFashionedRestrictions String comma-separated list of page
2288          *        restrictions from page table (pre 1.10)
2289          */
2290         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2291                 $rows = array();
2292
2293                 foreach ( $res as $row ) {
2294                         $rows[] = $row;
2295                 }
2296
2297                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2298         }
2299
2300         /**
2301          * Compiles list of active page restrictions from both page table (pre 1.10)
2302          * and page_restrictions table for this existing page.
2303          * Public for usage by LiquidThreads.
2304          *
2305          * @param $rows array of db result objects
2306          * @param $oldFashionedRestrictions string comma-separated list of page
2307          *        restrictions from page table (pre 1.10)
2308          */
2309         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2310                 global $wgContLang;
2311                 $dbr = wfGetDB( DB_SLAVE );
2312
2313                 $restrictionTypes = $this->getRestrictionTypes();
2314
2315                 foreach ( $restrictionTypes as $type ) {
2316                         $this->mRestrictions[$type] = array();
2317                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2318                 }
2319
2320                 $this->mCascadeRestriction = false;
2321
2322                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2323
2324                 if ( $oldFashionedRestrictions === null ) {
2325                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2326                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2327                 }
2328
2329                 if ( $oldFashionedRestrictions != '' ) {
2330
2331                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2332                                 $temp = explode( '=', trim( $restrict ) );
2333                                 if ( count( $temp ) == 1 ) {
2334                                         // old old format should be treated as edit/move restriction
2335                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2336                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2337                                 } else {
2338                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2339                                 }
2340                         }
2341
2342                         $this->mOldRestrictions = true;
2343
2344                 }
2345
2346                 if ( count( $rows ) ) {
2347                         # Current system - load second to make them override.
2348                         $now = wfTimestampNow();
2349                         $purgeExpired = false;
2350
2351                         # Cycle through all the restrictions.
2352                         foreach ( $rows as $row ) {
2353
2354                                 // Don't take care of restrictions types that aren't allowed
2355                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2356                                         continue;
2357
2358                                 // This code should be refactored, now that it's being used more generally,
2359                                 // But I don't really see any harm in leaving it in Block for now -werdna
2360                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2361
2362                                 // Only apply the restrictions if they haven't expired!
2363                                 if ( !$expiry || $expiry > $now ) {
2364                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2365                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2366
2367                                         $this->mCascadeRestriction |= $row->pr_cascade;
2368                                 } else {
2369                                         // Trigger a lazy purge of expired restrictions
2370                                         $purgeExpired = true;
2371                                 }
2372                         }
2373
2374                         if ( $purgeExpired ) {
2375                                 Title::purgeExpiredRestrictions();
2376                         }
2377                 }
2378
2379                 $this->mRestrictionsLoaded = true;
2380         }
2381
2382         /**
2383          * Load restrictions from the page_restrictions table
2384          *
2385          * @param $oldFashionedRestrictions String comma-separated list of page
2386          *        restrictions from page table (pre 1.10)
2387          */
2388         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2389                 global $wgContLang;
2390                 if ( !$this->mRestrictionsLoaded ) {
2391                         if ( $this->exists() ) {
2392                                 $dbr = wfGetDB( DB_SLAVE );
2393
2394                                 $res = $dbr->select(
2395                                         'page_restrictions',
2396                                         '*',
2397                                         array( 'pr_page' => $this->getArticleId() ),
2398                                         __METHOD__
2399                                 );
2400
2401                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2402                         } else {
2403                                 $title_protection = $this->getTitleProtection();
2404
2405                                 if ( $title_protection ) {
2406                                         $now = wfTimestampNow();
2407                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2408
2409                                         if ( !$expiry || $expiry > $now ) {
2410                                                 // Apply the restrictions
2411                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2412                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2413                                         } else { // Get rid of the old restrictions
2414                                                 Title::purgeExpiredRestrictions();
2415                                                 $this->mTitleProtection = false;
2416                                         }
2417                                 } else {
2418                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2419                                 }
2420                                 $this->mRestrictionsLoaded = true;
2421                         }
2422                 }
2423         }
2424
2425         /**
2426          * Purge expired restrictions from the page_restrictions table
2427          */
2428         static function purgeExpiredRestrictions() {
2429                 $dbw = wfGetDB( DB_MASTER );
2430                 $dbw->delete(
2431                         'page_restrictions',
2432                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2433                         __METHOD__
2434                 );
2435
2436                 $dbw->delete(
2437                         'protected_titles',
2438                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2439                         __METHOD__
2440                 );
2441         }
2442
2443         /**
2444          * Accessor/initialisation for mRestrictions
2445          *
2446          * @param $action String action that permission needs to be checked for
2447          * @return Array of Strings the array of groups allowed to edit this article
2448          */
2449         public function getRestrictions( $action ) {
2450                 if ( !$this->mRestrictionsLoaded ) {
2451                         $this->loadRestrictions();
2452                 }
2453                 return isset( $this->mRestrictions[$action] )
2454                                 ? $this->mRestrictions[$action]
2455                                 : array();
2456         }
2457
2458         /**
2459          * Get the expiry time for the restriction against a given action
2460          *
2461          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2462          *      or not protected at all, or false if the action is not recognised.
2463          */
2464         public function getRestrictionExpiry( $action ) {
2465                 if ( !$this->mRestrictionsLoaded ) {
2466                         $this->loadRestrictions();
2467                 }
2468                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2469         }
2470
2471         /**
2472          * Is there a version of this page in the deletion archive?
2473          *
2474          * @return Int the number of archived revisions
2475          */
2476         public function isDeleted() {
2477                 if ( $this->getNamespace() < 0 ) {
2478                         $n = 0;
2479                 } else {
2480                         $dbr = wfGetDB( DB_SLAVE );
2481
2482                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2483                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2484                                 __METHOD__
2485                         );
2486                         if ( $this->getNamespace() == NS_FILE ) {
2487                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2488                                         array( 'fa_name' => $this->getDBkey() ),
2489                                         __METHOD__
2490                                 );
2491                         }
2492                 }
2493                 return (int)$n;
2494         }
2495
2496         /**
2497          * Is there a version of this page in the deletion archive?
2498          *
2499          * @return Boolean
2500          */
2501         public function isDeletedQuick() {
2502                 if ( $this->getNamespace() < 0 ) {
2503                         return false;
2504                 }
2505                 $dbr = wfGetDB( DB_SLAVE );
2506                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2507                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2508                         __METHOD__
2509                 );
2510                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2511                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2512                                 array( 'fa_name' => $this->getDBkey() ),
2513                                 __METHOD__
2514                         );
2515                 }
2516                 return $deleted;
2517         }
2518
2519         /**
2520          * Get the article ID for this Title from the link cache,
2521          * adding it if necessary
2522          *
2523          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2524          *  for update
2525          * @return Int the ID
2526          */
2527         public function getArticleID( $flags = 0 ) {
2528                 if ( $this->getNamespace() < 0 ) {
2529                         return $this->mArticleID = 0;
2530                 }
2531                 $linkCache = LinkCache::singleton();
2532                 if ( $flags & self::GAID_FOR_UPDATE ) {
2533                         $oldUpdate = $linkCache->forUpdate( true );
2534                         $linkCache->clearLink( $this );
2535                         $this->mArticleID = $linkCache->addLinkObj( $this );
2536                         $linkCache->forUpdate( $oldUpdate );
2537                 } else {
2538                         if ( -1 == $this->mArticleID ) {
2539                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2540                         }
2541                 }
2542                 return $this->mArticleID;
2543         }
2544
2545         /**
2546          * Is this an article that is a redirect page?
2547          * Uses link cache, adding it if necessary
2548          *
2549          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2550          * @return Bool
2551          */
2552         public function isRedirect( $flags = 0 ) {
2553                 if ( !is_null( $this->mRedirect ) ) {
2554                         return $this->mRedirect;
2555                 }
2556                 # Calling getArticleID() loads the field from cache as needed
2557                 if ( !$this->getArticleID( $flags ) ) {
2558                         return $this->mRedirect = false;
2559                 }
2560                 $linkCache = LinkCache::singleton();
2561                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2562
2563                 return $this->mRedirect;
2564         }
2565
2566         /**
2567          * What is the length of this page?
2568          * Uses link cache, adding it if necessary
2569          *
2570          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2571          * @return Int
2572          */
2573         public function getLength( $flags = 0 ) {
2574                 if ( $this->mLength != -1 ) {
2575                         return $this->mLength;
2576                 }
2577                 # Calling getArticleID() loads the field from cache as needed
2578                 if ( !$this->getArticleID( $flags ) ) {
2579                         return $this->mLength = 0;
2580                 }
2581                 $linkCache = LinkCache::singleton();
2582                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2583
2584                 return $this->mLength;
2585         }
2586
2587         /**
2588          * What is the page_latest field for this page?
2589          *
2590          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2591          * @return Int or 0 if the page doesn't exist
2592          */
2593         public function getLatestRevID( $flags = 0 ) {
2594                 if ( $this->mLatestID !== false ) {
2595                         return intval( $this->mLatestID );
2596                 }
2597                 # Calling getArticleID() loads the field from cache as needed
2598                 if ( !$this->getArticleID( $flags ) ) {
2599                         return $this->mLatestID = 0;
2600                 }
2601                 $linkCache = LinkCache::singleton();
2602                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2603
2604                 return $this->mLatestID;
2605         }
2606
2607         /**
2608          * This clears some fields in this object, and clears any associated
2609          * keys in the "bad links" section of the link cache.
2610          *
2611          * - This is called from Article::doEdit() and Article::insertOn() to allow
2612          * loading of the new page_id. It's also called from
2613          * Article::doDeleteArticle()
2614          *
2615          * @param $newid Int the new Article ID
2616          */
2617         public function resetArticleID( $newid ) {
2618                 $linkCache = LinkCache::singleton();
2619                 $linkCache->clearLink( $this );
2620
2621                 if ( $newid === false ) {
2622                         $this->mArticleID = -1;
2623                 } else {
2624                         $this->mArticleID = intval( $newid );
2625                 }
2626                 $this->mRestrictionsLoaded = false;
2627                 $this->mRestrictions = array();
2628                 $this->mRedirect = null;
2629                 $this->mLength = -1;
2630                 $this->mLatestID = false;
2631         }
2632
2633         /**
2634          * Updates page_touched for this page; called from LinksUpdate.php
2635          *
2636          * @return Bool true if the update succeded
2637          */
2638         public function invalidateCache() {
2639                 if ( wfReadOnly() ) {
2640                         return false;
2641                 }
2642                 $dbw = wfGetDB( DB_MASTER );
2643                 $success = $dbw->update(
2644                         'page',
2645                         array( 'page_touched' => $dbw->timestamp() ),
2646                         $this->pageCond(),
2647                         __METHOD__
2648                 );
2649                 HTMLFileCache::clearFileCache( $this );
2650                 return $success;
2651         }
2652
2653         /**
2654          * Prefix some arbitrary text with the namespace or interwiki prefix
2655          * of this object
2656          *
2657          * @param $name String the text
2658          * @return String the prefixed text
2659          * @private
2660          */
2661         private function prefix( $name ) {
2662                 $p = '';
2663                 if ( $this->mInterwiki != '' ) {
2664                         $p = $this->mInterwiki . ':';
2665                 }
2666
2667                 if ( 0 != $this->mNamespace ) {
2668                         $p .= $this->getNsText() . ':';
2669                 }
2670                 return $p . $name;
2671         }
2672
2673         /**
2674          * Returns a simple regex that will match on characters and sequences invalid in titles.
2675          * Note that this doesn't pick up many things that could be wrong with titles, but that
2676          * replacing this regex with something valid will make many titles valid.
2677          *
2678          * @return String regex string
2679          */
2680         static function getTitleInvalidRegex() {
2681                 static $rxTc = false;
2682                 if ( !$rxTc ) {
2683                         # Matching titles will be held as illegal.
2684                         $rxTc = '/' .
2685                                 # Any character not allowed is forbidden...
2686                                 '[^' . Title::legalChars() . ']' .
2687                                 # URL percent encoding sequences interfere with the ability
2688                                 # to round-trip titles -- you can't link to them consistently.
2689                                 '|%[0-9A-Fa-f]{2}' .
2690                                 # XML/HTML character references produce similar issues.
2691                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2692                                 '|&#[0-9]+;' .
2693                                 '|&#x[0-9A-Fa-f]+;' .
2694                                 '/S';
2695                 }
2696
2697                 return $rxTc;
2698         }
2699
2700         /**
2701          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2702          *
2703          * @param $text String containing title to capitalize
2704          * @param $ns int namespace index, defaults to NS_MAIN
2705          * @return String containing capitalized title
2706          */
2707         public static function capitalize( $text, $ns = NS_MAIN ) {
2708                 global $wgContLang;
2709
2710                 if ( MWNamespace::isCapitalized( $ns ) ) {
2711                         return $wgContLang->ucfirst( $text );
2712                 } else {
2713                         return $text;
2714                 }
2715         }
2716
2717         /**
2718          * Secure and split - main initialisation function for this object
2719          *
2720          * Assumes that mDbkeyform has been set, and is urldecoded
2721          * and uses underscores, but not otherwise munged.  This function
2722          * removes illegal characters, splits off the interwiki and
2723          * namespace prefixes, sets the other forms, and canonicalizes
2724          * everything.
2725          *
2726          * @return Bool true on success
2727          */
2728         private function secureAndSplit() {
2729                 global $wgContLang, $wgLocalInterwiki;
2730
2731                 # Initialisation
2732                 $this->mInterwiki = $this->mFragment = '';
2733                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2734
2735                 $dbkey = $this->mDbkeyform;
2736
2737                 # Strip Unicode bidi override characters.
2738                 # Sometimes they slip into cut-n-pasted page titles, where the
2739                 # override chars get included in list displays.
2740                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2741
2742                 # Clean up whitespace
2743                 # Note: use of the /u option on preg_replace here will cause
2744                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2745                 # conveniently disabling them.
2746                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2747                 $dbkey = trim( $dbkey, '_' );
2748
2749                 if ( $dbkey == '' ) {
2750                         return false;
2751                 }
2752
2753                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2754                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2755                         return false;
2756                 }
2757
2758                 $this->mDbkeyform = $dbkey;
2759
2760                 # Initial colon indicates main namespace rather than specified default
2761                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2762                 if ( ':' == $dbkey[0] ) {
2763                         $this->mNamespace = NS_MAIN;
2764                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2765                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2766                 }
2767
2768                 # Namespace or interwiki prefix
2769                 $firstPass = true;
2770                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2771                 do {
2772                         $m = array();
2773                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2774                                 $p = $m[1];
2775                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2776                                         # Ordinary namespace
2777                                         $dbkey = $m[2];
2778                                         $this->mNamespace = $ns;
2779                                         # For Talk:X pages, check if X has a "namespace" prefix
2780                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2781                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2782                                                         # Disallow Talk:File:x type titles...
2783                                                         return false;
2784                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2785                                                         # Disallow Talk:Interwiki:x type titles...
2786                                                         return false;
2787                                                 }
2788                                         }
2789                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2790                                         if ( !$firstPass ) {
2791                                                 # Can't make a local interwiki link to an interwiki link.
2792                                                 # That's just crazy!
2793                                                 return false;
2794                                         }
2795
2796                                         # Interwiki link
2797                                         $dbkey = $m[2];
2798                                         $this->mInterwiki = $wgContLang->lc( $p );
2799
2800                                         # Redundant interwiki prefix to the local wiki
2801                                         if ( $wgLocalInterwiki !== false
2802                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2803                                         {
2804                                                 if ( $dbkey == '' ) {
2805                                                         # Can't have an empty self-link
2806                                                         return false;
2807                                                 }
2808                                                 $this->mInterwiki = '';
2809                                                 $firstPass = false;
2810                                                 # Do another namespace split...
2811                                                 continue;
2812                                         }
2813
2814                                         # If there's an initial colon after the interwiki, that also
2815                                         # resets the default namespace
2816                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2817                                                 $this->mNamespace = NS_MAIN;
2818                                                 $dbkey = substr( $dbkey, 1 );
2819                                         }
2820                                 }
2821                                 # If there's no recognized interwiki or namespace,
2822                                 # then let the colon expression be part of the title.
2823                         }
2824                         break;
2825                 } while ( true );
2826
2827                 # We already know that some pages won't be in the database!
2828                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2829                         $this->mArticleID = 0;
2830                 }
2831                 $fragment = strstr( $dbkey, '#' );
2832                 if ( false !== $fragment ) {
2833                         $this->setFragment( $fragment );
2834                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2835                         # remove whitespace again: prevents "Foo_bar_#"
2836                         # becoming "Foo_bar_"
2837                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2838                 }
2839
2840                 # Reject illegal characters.
2841                 $rxTc = self::getTitleInvalidRegex();
2842                 if ( preg_match( $rxTc, $dbkey ) ) {
2843                         return false;
2844                 }
2845
2846                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2847                 # reachable due to the way web browsers deal with 'relative' URLs.
2848                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2849                 if ( strpos( $dbkey, '.' ) !== false &&
2850                          ( $dbkey === '.' || $dbkey === '..' ||
2851                            strpos( $dbkey, './' ) === 0  ||
2852                            strpos( $dbkey, '../' ) === 0 ||
2853                            strpos( $dbkey, '/./' ) !== false ||
2854                            strpos( $dbkey, '/../' ) !== false  ||
2855                            substr( $dbkey, -2 ) == '/.' ||
2856                            substr( $dbkey, -3 ) == '/..' ) )
2857                 {
2858                         return false;
2859                 }
2860
2861                 # Magic tilde sequences? Nu-uh!
2862                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2863                         return false;
2864                 }
2865
2866                 # Limit the size of titles to 255 bytes. This is typically the size of the
2867                 # underlying database field. We make an exception for special pages, which
2868                 # don't need to be stored in the database, and may edge over 255 bytes due
2869                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2870                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2871                   strlen( $dbkey ) > 512 )
2872                 {
2873                         return false;
2874                 }
2875
2876                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2877                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2878                 # other site might be case-sensitive.
2879                 $this->mUserCaseDBKey = $dbkey;
2880                 if ( $this->mInterwiki == '' ) {
2881                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2882                 }
2883
2884                 # Can't make a link to a namespace alone... "empty" local links can only be
2885                 # self-links with a fragment identifier.
2886                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2887                         return false;
2888                 }
2889
2890                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2891                 // IP names are not allowed for accounts, and can only be referring to
2892                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2893                 // there are numerous ways to present the same IP. Having sp:contribs scan
2894                 // them all is silly and having some show the edits and others not is
2895                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2896                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2897                         ? IP::sanitizeIP( $dbkey )
2898                         : $dbkey;
2899
2900                 // Any remaining initial :s are illegal.
2901                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
2902                         return false;
2903                 }
2904
2905                 # Fill fields
2906                 $this->mDbkeyform = $dbkey;
2907                 $this->mUrlform = wfUrlencode( $dbkey );
2908
2909                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2910
2911                 return true;
2912         }
2913
2914         /**
2915          * Set the fragment for this title. Removes the first character from the
2916          * specified fragment before setting, so it assumes you're passing it with
2917          * an initial "#".
2918          *
2919          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2920          * Still in active use privately.
2921          *
2922          * @param $fragment String text
2923          */
2924         public function setFragment( $fragment ) {
2925                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2926         }
2927
2928         /**
2929          * Get a Title object associated with the talk page of this article
2930          *
2931          * @return Title the object for the talk page
2932          */
2933         public function getTalkPage() {
2934                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2935         }
2936
2937         /**
2938          * Get a title object associated with the subject page of this
2939          * talk page
2940          *
2941          * @return Title the object for the subject page
2942          */
2943         public function getSubjectPage() {
2944                 // Is this the same title?
2945                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2946                 if ( $this->getNamespace() == $subjectNS ) {
2947                         return $this;
2948                 }
2949                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2950         }
2951
2952         /**
2953          * Get an array of Title objects linking to this Title
2954          * Also stores the IDs in the link cache.
2955          *
2956          * WARNING: do not use this function on arbitrary user-supplied titles!
2957          * On heavily-used templates it will max out the memory.
2958          *
2959          * @param $options Array: may be FOR UPDATE
2960          * @param $table String: table name
2961          * @param $prefix String: fields prefix
2962          * @return Array of Title objects linking here
2963          */
2964         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2965                 $linkCache = LinkCache::singleton();
2966
2967                 if ( count( $options ) > 0 ) {
2968                         $db = wfGetDB( DB_MASTER );
2969                 } else {
2970                         $db = wfGetDB( DB_SLAVE );
2971                 }
2972
2973                 $res = $db->select(
2974                         array( 'page', $table ),
2975                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2976                         array(
2977                                 "{$prefix}_from=page_id",
2978                                 "{$prefix}_namespace" => $this->getNamespace(),
2979                                 "{$prefix}_title"     => $this->getDBkey() ),
2980                         __METHOD__,
2981                         $options
2982                 );
2983
2984                 $retVal = array();
2985                 if ( $db->numRows( $res ) ) {
2986                         foreach ( $res as $row ) {
2987                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2988                                 if ( $titleObj ) {
2989                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
2990                                         $retVal[] = $titleObj;
2991                                 }
2992                         }
2993                 }
2994                 return $retVal;
2995         }
2996
2997         /**
2998          * Get an array of Title objects using this Title as a template
2999          * Also stores the IDs in the link cache.
3000          *
3001          * WARNING: do not use this function on arbitrary user-supplied titles!
3002          * On heavily-used templates it will max out the memory.
3003          *
3004          * @param $options Array: may be FOR UPDATE
3005          * @return Array of Title the Title objects linking here
3006          */
3007         public function getTemplateLinksTo( $options = array() ) {
3008                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3009         }
3010
3011         /**
3012          * Get an array of Title objects referring to non-existent articles linked from this page
3013          *
3014          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3015          * @return Array of Title the Title objects
3016          */
3017         public function getBrokenLinksFrom() {
3018                 if ( $this->getArticleId() == 0 ) {
3019                         # All links from article ID 0 are false positives
3020                         return array();
3021                 }
3022
3023                 $dbr = wfGetDB( DB_SLAVE );
3024                 $res = $dbr->select(
3025                         array( 'page', 'pagelinks' ),
3026                         array( 'pl_namespace', 'pl_title' ),
3027                         array(
3028                                 'pl_from' => $this->getArticleId(),
3029                                 'page_namespace IS NULL'
3030                         ),
3031                         __METHOD__, array(),
3032                         array(
3033                                 'page' => array(
3034                                         'LEFT JOIN',
3035                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3036                                 )
3037                         )
3038                 );
3039
3040                 $retVal = array();
3041                 foreach ( $res as $row ) {
3042                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3043                 }
3044                 return $retVal;
3045         }
3046
3047
3048         /**
3049          * Get a list of URLs to purge from the Squid cache when this
3050          * page changes
3051          *
3052          * @return Array of String the URLs
3053          */
3054         public function getSquidURLs() {
3055                 global $wgContLang;
3056
3057                 $urls = array(
3058                         $this->getInternalURL(),
3059                         $this->getInternalURL( 'action=history' )
3060                 );
3061
3062                 // purge variant urls as well
3063                 if ( $wgContLang->hasVariants() ) {
3064                         $variants = $wgContLang->getVariants();
3065                         foreach ( $variants as $vCode ) {
3066                                 $urls[] = $this->getInternalURL( '', $vCode );
3067                         }
3068                 }
3069
3070                 return $urls;
3071         }
3072
3073         /**
3074          * Purge all applicable Squid URLs
3075          */
3076         public function purgeSquid() {
3077                 global $wgUseSquid;
3078                 if ( $wgUseSquid ) {
3079                         $urls = $this->getSquidURLs();
3080                         $u = new SquidUpdate( $urls );
3081                         $u->doUpdate();
3082                 }
3083         }
3084
3085         /**
3086          * Move this page without authentication
3087          *
3088          * @param $nt Title the new page Title
3089          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3090          */
3091         public function moveNoAuth( &$nt ) {
3092                 return $this->moveTo( $nt, false );
3093         }
3094
3095         /**
3096          * Check whether a given move operation would be valid.
3097          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3098          *
3099          * @param $nt Title the new title
3100          * @param $auth Bool indicates whether $wgUser's permissions
3101          *  should be checked
3102          * @param $reason String is the log summary of the move, used for spam checking
3103          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3104          */
3105         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3106                 global $wgUser;
3107
3108                 $errors = array();
3109                 if ( !$nt ) {
3110                         // Normally we'd add this to $errors, but we'll get
3111                         // lots of syntax errors if $nt is not an object
3112                         return array( array( 'badtitletext' ) );
3113                 }
3114                 if ( $this->equals( $nt ) ) {
3115                         $errors[] = array( 'selfmove' );
3116                 }
3117                 if ( !$this->isMovable() ) {
3118                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3119                 }
3120                 if ( $nt->getInterwiki() != '' ) {
3121                         $errors[] = array( 'immobile-target-namespace-iw' );
3122                 }
3123                 if ( !$nt->isMovable() ) {
3124                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3125                 }
3126
3127                 $oldid = $this->getArticleID();
3128                 $newid = $nt->getArticleID();
3129
3130                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3131                         $errors[] = array( 'articleexists' );
3132                 }
3133                 if ( ( $this->getDBkey() == '' ) ||
3134                          ( !$oldid ) ||
3135                          ( $nt->getDBkey() == '' ) ) {
3136                         $errors[] = array( 'badarticleerror' );
3137                 }
3138
3139                 // Image-specific checks
3140                 if ( $this->getNamespace() == NS_FILE ) {
3141                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3142                 }
3143
3144                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3145                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3146                 }
3147
3148                 if ( $auth ) {
3149                         $errors = wfMergeErrorArrays( $errors,
3150                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3151                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3152                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3153                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3154                 }
3155
3156                 $match = EditPage::matchSummarySpamRegex( $reason );
3157                 if ( $match !== false ) {
3158                         // This is kind of lame, won't display nice
3159                         $errors[] = array( 'spamprotectiontext' );
3160                 }
3161
3162                 $err = null;
3163                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3164                         $errors[] = array( 'hookaborted', $err );
3165                 }
3166
3167                 # The move is allowed only if (1) the target doesn't exist, or
3168                 # (2) the target is a redirect to the source, and has no history
3169                 # (so we can undo bad moves right after they're done).
3170
3171                 if ( 0 != $newid ) { # Target exists; check for validity
3172                         if ( !$this->isValidMoveTarget( $nt ) ) {
3173                                 $errors[] = array( 'articleexists' );
3174                         }
3175                 } else {
3176                         $tp = $nt->getTitleProtection();
3177                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3178                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3179                                 $errors[] = array( 'cantmove-titleprotected' );
3180                         }
3181                 }
3182                 if ( empty( $errors ) ) {
3183                         return true;
3184                 }
3185                 return $errors;
3186         }
3187
3188         /**
3189          * Check if the requested move target is a valid file move target
3190          * @param Title $nt Target title
3191          * @return array List of errors
3192          */
3193         protected function validateFileMoveOperation( $nt ) {
3194                 global $wgUser;
3195
3196                 $errors = array();
3197
3198                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3199
3200                 $file = wfLocalFile( $this );
3201                 if ( $file->exists() ) {
3202                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3203                                 $errors[] = array( 'imageinvalidfilename' );
3204                         }
3205                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3206                                 $errors[] = array( 'imagetypemismatch' );
3207                         }
3208                 }
3209
3210                 if ( $nt->getNamespace() != NS_FILE ) {
3211                         $errors[] = array( 'imagenocrossnamespace' );
3212                         // From here we want to do checks on a file object, so if we can't
3213                         // create one, we must return.
3214                         return $errors;
3215                 }
3216
3217                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3218
3219                 $destFile = wfLocalFile( $nt );
3220                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3221                         $errors[] = array( 'file-exists-sharedrepo' );
3222                 }
3223
3224                 return $errors;
3225         }
3226
3227         /**
3228          * Move a title to a new location
3229          *
3230          * @param $nt Title the new title
3231          * @param $auth Bool indicates whether $wgUser's permissions
3232          *  should be checked
3233          * @param $reason String the reason for the move
3234          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3235          *  Ignored if the user doesn't have the suppressredirect right.
3236          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3237          */
3238         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3239                 global $wgUser;
3240                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3241                 if ( is_array( $err ) ) {
3242                         // Auto-block user's IP if the account was "hard" blocked
3243                         $wgUser->spreadAnyEditBlock();
3244                         return $err;
3245                 }
3246
3247                 // If it is a file, move it first.
3248                 // It is done before all other moving stuff is done because it's hard to revert.
3249                 $dbw = wfGetDB( DB_MASTER );
3250                 if ( $this->getNamespace() == NS_FILE ) {
3251                         $file = wfLocalFile( $this );
3252                         if ( $file->exists() ) {
3253                                 $status = $file->move( $nt );
3254                                 if ( !$status->isOk() ) {
3255                                         return $status->getErrorsArray();
3256                                 }
3257                         }
3258                 }
3259                 // Clear RepoGroup process cache
3260                 RepoGroup::singleton()->clearCache( $this );
3261                 RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3262
3263                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3264                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3265                 $protected = $this->isProtected();
3266                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3267
3268                 // Do the actual move
3269                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3270                 if ( is_array( $err ) ) {
3271                         # @todo FIXME: What about the File we have already moved?
3272                         $dbw->rollback();
3273                         return $err;
3274                 }
3275
3276                 $redirid = $this->getArticleID();
3277
3278                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3279                 // cl_timestamp, which may disturb time-based lists on some sites.
3280                 $prefixes = $dbw->select(
3281                         'categorylinks',
3282                         array( 'cl_sortkey_prefix', 'cl_to' ),
3283                         array( 'cl_from' => $pageid ),
3284                         __METHOD__
3285                 );
3286                 foreach ( $prefixes as $prefixRow ) {
3287                         $prefix = $prefixRow->cl_sortkey_prefix;
3288                         $catTo = $prefixRow->cl_to;
3289                         $dbw->update( 'categorylinks',
3290                                 array(
3291                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3292                                                 $nt->getCategorySortkey( $prefix ) ),
3293                                         'cl_timestamp=cl_timestamp' ),
3294                                 array(
3295                                         'cl_from' => $pageid,
3296                                         'cl_to' => $catTo ),
3297                                 __METHOD__
3298                         );
3299                 }
3300
3301                 if ( $protected ) {
3302                         # Protect the redirect title as the title used to be...
3303                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3304                                 array(
3305                                         'pr_page'    => $redirid,
3306                                         'pr_type'    => 'pr_type',
3307                                         'pr_level'   => 'pr_level',
3308                                         'pr_cascade' => 'pr_cascade',
3309                                         'pr_user'    => 'pr_user',
3310                                         'pr_expiry'  => 'pr_expiry'
3311                                 ),
3312                                 array( 'pr_page' => $pageid ),
3313                                 __METHOD__,
3314                                 array( 'IGNORE' )
3315                         );
3316                         # Update the protection log
3317                         $log = new LogPage( 'protect' );
3318                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3319                         if ( $reason ) {
3320                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3321                         }
3322                         // @todo FIXME: $params?
3323                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3324                 }
3325
3326                 # Update watchlists
3327                 $oldnamespace = $this->getNamespace() & ~1;
3328                 $newnamespace = $nt->getNamespace() & ~1;
3329                 $oldtitle = $this->getDBkey();
3330                 $newtitle = $nt->getDBkey();
3331
3332                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3333                         WatchedItem::duplicateEntries( $this, $nt );
3334                 }
3335
3336                 # Update search engine
3337                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3338                 $u->doUpdate();
3339                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3340                 $u->doUpdate();
3341
3342                 $dbw->commit();
3343
3344                 # Update site_stats
3345                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3346                         # No longer a content page
3347                         # Not viewed, edited, removing
3348                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3349                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3350                         # Now a content page
3351                         # Not viewed, edited, adding
3352                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3353                 } elseif ( $pageCountChange ) {
3354                         # Redirect added
3355                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3356                 } else {
3357                         # Nothing special
3358                         $u = false;
3359                 }
3360                 if ( $u ) {
3361                         $u->doUpdate();
3362                 }
3363
3364                 # Update message cache for interface messages
3365                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3366                         # @bug 17860: old article can be deleted, if this the case,
3367                         # delete it from message cache
3368                         if ( $this->getArticleID() === 0 ) {
3369                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3370                         } else {
3371                                 $rev = Revision::newFromTitle( $this );
3372                                 MessageCache::singleton()->replace( $this->getDBkey(), $rev->getText() );
3373                         }
3374                 }
3375                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3376                         $rev = Revision::newFromTitle( $nt );
3377                         MessageCache::singleton()->replace( $nt->getDBkey(), $rev->getText() );
3378                 }
3379
3380                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3381                 return true;
3382         }
3383
3384         /**
3385          * Move page to a title which is either a redirect to the
3386          * source page or nonexistent
3387          *
3388          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3389          * @param $reason String The reason for the move
3390          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3391          *   if the user doesn't have the suppressredirect right
3392          */
3393         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3394                 global $wgUser, $wgContLang;
3395
3396                 if ( $nt->exists() ) {
3397                         $moveOverRedirect = true;
3398                         $logType = 'move_redir';
3399                 } else {
3400                         $moveOverRedirect = false;
3401                         $logType = 'move';
3402                 }
3403
3404                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3405
3406                 $logEntry = new ManualLogEntry( 'move', $logType );
3407                 $logEntry->setPerformer( $wgUser );
3408                 $logEntry->setTarget( $this );
3409                 $logEntry->setComment( $reason );
3410                 $logEntry->setParameters( array(
3411                         '4::target' => $nt->getPrefixedText(),
3412                         '5::noredir' => $redirectSuppressed ? '1': '0',
3413                 ) );
3414
3415                 $formatter = LogFormatter::newFromEntry( $logEntry );
3416                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3417                 $comment = $formatter->getPlainActionText();
3418                 if ( $reason ) {
3419                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3420                 }
3421                 # Truncate for whole multibyte characters.
3422                 $comment = $wgContLang->truncate( $comment, 255 );
3423
3424                 $oldid = $this->getArticleID();
3425                 $latest = $this->getLatestRevID();
3426
3427                 $dbw = wfGetDB( DB_MASTER );
3428
3429                 if ( $moveOverRedirect ) {
3430                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3431
3432                         $newid = $nt->getArticleID();
3433                         $newns = $nt->getNamespace();
3434                         $newdbk = $nt->getDBkey();
3435
3436                         # Delete the old redirect. We don't save it to history since
3437                         # by definition if we've got here it's rather uninteresting.
3438                         # We have to remove it so that the next step doesn't trigger
3439                         # a conflict on the unique namespace+title index...
3440                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3441                         if ( !$dbw->cascadingDeletes() ) {
3442                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3443
3444                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3445                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3446                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3447                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3448                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3449                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3450                                 $dbw->delete( 'iwlinks', array( 'iwl_from' => $newid ), __METHOD__ );
3451                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3452                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3453                         }
3454                         // If the target page was recently created, it may have an entry in recentchanges still
3455                         $dbw->delete( 'recentchanges',
3456                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3457                                 __METHOD__
3458                         );
3459                 }
3460
3461                 # Save a null revision in the page's history notifying of the move
3462                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3463                 if ( !is_object( $nullRevision ) ) {
3464                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3465                 }
3466                 $nullRevId = $nullRevision->insertOn( $dbw );
3467
3468                 $now = wfTimestampNow();
3469                 # Change the name of the target page:
3470                 $dbw->update( 'page',
3471                         /* SET */ array(
3472                                 'page_touched'   => $dbw->timestamp( $now ),
3473                                 'page_namespace' => $nt->getNamespace(),
3474                                 'page_title'     => $nt->getDBkey(),
3475                                 'page_latest'    => $nullRevId,
3476                         ),
3477                         /* WHERE */ array( 'page_id' => $oldid ),
3478                         __METHOD__
3479                 );
3480                 $nt->resetArticleID( $oldid );
3481
3482                 $article = WikiPage::factory( $nt );
3483                 wfRunHooks( 'NewRevisionFromEditComplete',
3484                         array( $article, $nullRevision, $latest, $wgUser ) );
3485                 $article->setCachedLastEditTime( $now );
3486
3487                 # Recreate the redirect, this time in the other direction.
3488                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3489                         $mwRedir = MagicWord::get( 'redirect' );
3490                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3491                         $redirectArticle = WikiPage::factory( $this );
3492                         $newid = $redirectArticle->insertOn( $dbw );
3493                         if ( $newid ) { // sanity
3494                                 $redirectRevision = new Revision( array(
3495                                         'page'    => $newid,
3496                                         'comment' => $comment,
3497                                         'text'    => $redirectText ) );
3498                                 $redirectRevision->insertOn( $dbw );
3499                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3500
3501                                 wfRunHooks( 'NewRevisionFromEditComplete',
3502                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3503
3504                                 # Now, we record the link from the redirect to the new title.
3505                                 # It should have no other outgoing links...
3506                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3507                                 $dbw->insert( 'pagelinks',
3508                                         array(
3509                                                 'pl_from'      => $newid,
3510                                                 'pl_namespace' => $nt->getNamespace(),
3511                                                 'pl_title'     => $nt->getDBkey() ),
3512                                         __METHOD__ );
3513                         }
3514                 } else {
3515                         $this->resetArticleID( 0 );
3516                 }
3517
3518                 # Log the move
3519                 $logid = $logEntry->insert();
3520                 $logEntry->publish( $logid );
3521
3522                 # Purge caches for old and new titles
3523                 if ( $moveOverRedirect ) {
3524                         # A simple purge is enough when moving over a redirect
3525                         $nt->purgeSquid();
3526                 } else {
3527                         # Purge caches as per article creation, including any pages that link to this title
3528                         Article::onArticleCreate( $nt );
3529                 }
3530                 $this->purgeSquid();
3531         }
3532
3533         /**
3534          * Move this page's subpages to be subpages of $nt
3535          *
3536          * @param $nt Title Move target
3537          * @param $auth bool Whether $wgUser's permissions should be checked
3538          * @param $reason string The reason for the move
3539          * @param $createRedirect bool Whether to create redirects from the old subpages to
3540          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3541          * @return mixed array with old page titles as keys, and strings (new page titles) or
3542          *     arrays (errors) as values, or an error array with numeric indices if no pages
3543          *     were moved
3544          */
3545         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3546                 global $wgMaximumMovedPages;
3547                 // Check permissions
3548                 if ( !$this->userCan( 'move-subpages' ) ) {
3549                         return array( 'cant-move-subpages' );
3550                 }
3551                 // Do the source and target namespaces support subpages?
3552                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3553                         return array( 'namespace-nosubpages',
3554                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3555                 }
3556                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3557                         return array( 'namespace-nosubpages',
3558                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3559                 }
3560
3561                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3562                 $retval = array();
3563                 $count = 0;
3564                 foreach ( $subpages as $oldSubpage ) {
3565                         $count++;
3566                         if ( $count > $wgMaximumMovedPages ) {
3567                                 $retval[$oldSubpage->getPrefixedTitle()] =
3568                                                 array( 'movepage-max-pages',
3569                                                         $wgMaximumMovedPages );
3570                                 break;
3571                         }
3572
3573                         // We don't know whether this function was called before
3574                         // or after moving the root page, so check both
3575                         // $this and $nt
3576                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3577                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3578                         {
3579                                 // When moving a page to a subpage of itself,
3580                                 // don't move it twice
3581                                 continue;
3582                         }
3583                         $newPageName = preg_replace(
3584                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3585                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3586                                         $oldSubpage->getDBkey() );
3587                         if ( $oldSubpage->isTalkPage() ) {
3588                                 $newNs = $nt->getTalkPage()->getNamespace();
3589                         } else {
3590                                 $newNs = $nt->getSubjectPage()->getNamespace();
3591                         }
3592                         # Bug 14385: we need makeTitleSafe because the new page names may
3593                         # be longer than 255 characters.
3594                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3595
3596                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3597                         if ( $success === true ) {
3598                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3599                         } else {
3600                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3601                         }
3602                 }
3603                 return $retval;
3604         }
3605
3606         /**
3607          * Checks if this page is just a one-rev redirect.
3608          * Adds lock, so don't use just for light purposes.
3609          *
3610          * @return Bool
3611          */
3612         public function isSingleRevRedirect() {
3613                 $dbw = wfGetDB( DB_MASTER );
3614                 # Is it a redirect?
3615                 $row = $dbw->selectRow( 'page',
3616                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3617                         $this->pageCond(),
3618                         __METHOD__,
3619                         array( 'FOR UPDATE' )
3620                 );
3621                 # Cache some fields we may want
3622                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3623                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3624                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3625                 if ( !$this->mRedirect ) {
3626                         return false;
3627                 }
3628                 # Does the article have a history?
3629                 $row = $dbw->selectField( array( 'page', 'revision' ),
3630                         'rev_id',
3631                         array( 'page_namespace' => $this->getNamespace(),
3632                                 'page_title' => $this->getDBkey(),
3633                                 'page_id=rev_page',
3634                                 'page_latest != rev_id'
3635                         ),
3636                         __METHOD__,
3637                         array( 'FOR UPDATE' )
3638                 );
3639                 # Return true if there was no history
3640                 return ( $row === false );
3641         }
3642
3643         /**
3644          * Checks if $this can be moved to a given Title
3645          * - Selects for update, so don't call it unless you mean business
3646          *
3647          * @param $nt Title the new title to check
3648          * @return Bool
3649          */
3650         public function isValidMoveTarget( $nt ) {
3651                 # Is it an existing file?
3652                 if ( $nt->getNamespace() == NS_FILE ) {
3653                         $file = wfLocalFile( $nt );
3654                         if ( $file->exists() ) {
3655                                 wfDebug( __METHOD__ . ": file exists\n" );
3656                                 return false;
3657                         }
3658                 }
3659                 # Is it a redirect with no history?
3660                 if ( !$nt->isSingleRevRedirect() ) {
3661                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3662                         return false;
3663                 }
3664                 # Get the article text
3665                 $rev = Revision::newFromTitle( $nt );
3666                 if( !is_object( $rev ) ){
3667                         return false;
3668                 }
3669                 $text = $rev->getText();
3670                 # Does the redirect point to the source?
3671                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3672                 $m = array();
3673                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3674                         $redirTitle = Title::newFromText( $m[1] );
3675                         if ( !is_object( $redirTitle ) ||
3676                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3677                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3678                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3679                                 return false;
3680                         }
3681                 } else {
3682                         # Fail safe
3683                         wfDebug( __METHOD__ . ": failsafe\n" );
3684                         return false;
3685                 }
3686                 return true;
3687         }
3688
3689         /**
3690          * Can this title be added to a user's watchlist?
3691          *
3692          * @return Bool TRUE or FALSE
3693          */
3694         public function isWatchable() {
3695                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3696         }
3697
3698         /**
3699          * Get categories to which this Title belongs and return an array of
3700          * categories' names.
3701          *
3702          * @return Array of parents in the form:
3703          *        $parent => $currentarticle
3704          */
3705         public function getParentCategories() {
3706                 global $wgContLang;
3707
3708                 $data = array();
3709
3710                 $titleKey = $this->getArticleId();
3711
3712                 if ( $titleKey === 0 ) {
3713                         return $data;
3714                 }
3715
3716                 $dbr = wfGetDB( DB_SLAVE );
3717
3718                 $res = $dbr->select( 'categorylinks', '*',
3719                         array(
3720                                 'cl_from' => $titleKey,
3721                         ),
3722                         __METHOD__,
3723                         array()
3724                 );
3725
3726                 if ( $dbr->numRows( $res ) > 0 ) {
3727                         foreach ( $res as $row ) {
3728                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3729                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3730                         }
3731                 }
3732                 return $data;
3733         }
3734
3735         /**
3736          * Get a tree of parent categories
3737          *
3738          * @param $children Array with the children in the keys, to check for circular refs
3739          * @return Array Tree of parent categories
3740          */
3741         public function getParentCategoryTree( $children = array() ) {
3742                 $stack = array();
3743                 $parents = $this->getParentCategories();
3744
3745                 if ( $parents ) {
3746                         foreach ( $parents as $parent => $current ) {
3747                                 if ( array_key_exists( $parent, $children ) ) {
3748                                         # Circular reference
3749                                         $stack[$parent] = array();
3750                                 } else {
3751                                         $nt = Title::newFromText( $parent );
3752                                         if ( $nt ) {
3753                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3754                                         }
3755                                 }
3756                         }
3757                 }
3758
3759                 return $stack;
3760         }
3761
3762         /**
3763          * Get an associative array for selecting this title from
3764          * the "page" table
3765          *
3766          * @return Array suitable for the $where parameter of DB::select()
3767          */
3768         public function pageCond() {
3769                 if ( $this->mArticleID > 0 ) {
3770                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3771                         return array( 'page_id' => $this->mArticleID );
3772                 } else {
3773                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3774                 }
3775         }
3776
3777         /**
3778          * Get the revision ID of the previous revision
3779          *
3780          * @param $revId Int Revision ID. Get the revision that was before this one.
3781          * @param $flags Int Title::GAID_FOR_UPDATE
3782          * @return Int|Bool Old revision ID, or FALSE if none exists
3783          */
3784         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3785                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3786                 return $db->selectField( 'revision', 'rev_id',
3787                         array(
3788                                 'rev_page' => $this->getArticleId( $flags ),
3789                                 'rev_id < ' . intval( $revId )
3790                         ),
3791                         __METHOD__,
3792                         array( 'ORDER BY' => 'rev_id DESC' )
3793                 );
3794         }
3795
3796         /**
3797          * Get the revision ID of the next revision
3798          *
3799          * @param $revId Int Revision ID. Get the revision that was after this one.
3800          * @param $flags Int Title::GAID_FOR_UPDATE
3801          * @return Int|Bool Next revision ID, or FALSE if none exists
3802          */
3803         public function getNextRevisionID( $revId, $flags = 0 ) {
3804                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3805                 return $db->selectField( 'revision', 'rev_id',
3806                         array(
3807                                 'rev_page' => $this->getArticleId( $flags ),
3808                                 'rev_id > ' . intval( $revId )
3809                         ),
3810                         __METHOD__,
3811                         array( 'ORDER BY' => 'rev_id' )
3812                 );
3813         }
3814
3815         /**
3816          * Get the first revision of the page
3817          *
3818          * @param $flags Int Title::GAID_FOR_UPDATE
3819          * @return Revision|Null if page doesn't exist
3820          */
3821         public function getFirstRevision( $flags = 0 ) {
3822                 $pageId = $this->getArticleId( $flags );
3823                 if ( $pageId ) {
3824                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3825                         $row = $db->selectRow( 'revision', '*',
3826                                 array( 'rev_page' => $pageId ),
3827                                 __METHOD__,
3828                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3829                         );
3830                         if ( $row ) {
3831                                 return new Revision( $row );
3832                         }
3833                 }
3834                 return null;
3835         }
3836
3837         /**
3838          * Get the oldest revision timestamp of this page
3839          *
3840          * @param $flags Int Title::GAID_FOR_UPDATE
3841          * @return String: MW timestamp
3842          */
3843         public function getEarliestRevTime( $flags = 0 ) {
3844                 $rev = $this->getFirstRevision( $flags );
3845                 return $rev ? $rev->getTimestamp() : null;
3846         }
3847
3848         /**
3849          * Check if this is a new page
3850          *
3851          * @return bool
3852          */
3853         public function isNewPage() {
3854                 $dbr = wfGetDB( DB_SLAVE );
3855                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3856         }
3857
3858         /**
3859          * Get the number of revisions between the given revision.
3860          * Used for diffs and other things that really need it.
3861          *
3862          * @param $old int|Revision Old revision or rev ID (first before range)
3863          * @param $new int|Revision New revision or rev ID (first after range)
3864          * @return Int Number of revisions between these revisions.
3865          */
3866         public function countRevisionsBetween( $old, $new ) {
3867                 if ( !( $old instanceof Revision ) ) {
3868                         $old = Revision::newFromTitle( $this, (int)$old );
3869                 }
3870                 if ( !( $new instanceof Revision ) ) {
3871                         $new = Revision::newFromTitle( $this, (int)$new );
3872                 }
3873                 if ( !$old || !$new ) {
3874                         return 0; // nothing to compare
3875                 }
3876                 $dbr = wfGetDB( DB_SLAVE );
3877                 return (int)$dbr->selectField( 'revision', 'count(*)',
3878                         array(
3879                                 'rev_page' => $this->getArticleId(),
3880                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3881                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3882                         ),
3883                         __METHOD__
3884                 );
3885         }
3886
3887         /**
3888          * Get the number of authors between the given revision IDs.
3889          * Used for diffs and other things that really need it.
3890          *
3891          * @param $old int|Revision Old revision or rev ID (first before range)
3892          * @param $new int|Revision New revision or rev ID (first after range)
3893          * @param $limit Int Maximum number of authors
3894          * @return Int Number of revision authors between these revisions.
3895          */
3896         public function countAuthorsBetween( $old, $new, $limit ) {
3897                 if ( !( $old instanceof Revision ) ) {
3898                         $old = Revision::newFromTitle( $this, (int)$old );
3899                 }
3900                 if ( !( $new instanceof Revision ) ) {
3901                         $new = Revision::newFromTitle( $this, (int)$new );
3902                 }
3903                 if ( !$old || !$new ) {
3904                         return 0; // nothing to compare
3905                 }
3906                 $dbr = wfGetDB( DB_SLAVE );
3907                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3908                         array(
3909                                 'rev_page' => $this->getArticleID(),
3910                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3911                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3912                         ), __METHOD__,
3913                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3914                 );
3915                 return (int)$dbr->numRows( $res );
3916         }
3917
3918         /**
3919          * Compare with another title.
3920          *
3921          * @param $title Title
3922          * @return Bool
3923          */
3924         public function equals( Title $title ) {
3925                 // Note: === is necessary for proper matching of number-like titles.
3926                 return $this->getInterwiki() === $title->getInterwiki()
3927                         && $this->getNamespace() == $title->getNamespace()
3928                         && $this->getDBkey() === $title->getDBkey();
3929         }
3930
3931         /**
3932          * Check if this title is a subpage of another title
3933          *
3934          * @param $title Title
3935          * @return Bool
3936          */
3937         public function isSubpageOf( Title $title ) {
3938                 return $this->getInterwiki() === $title->getInterwiki()
3939                         && $this->getNamespace() == $title->getNamespace()
3940                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
3941         }
3942
3943         /**
3944          * Callback for usort() to do title sorts by (namespace, title)
3945          *
3946          * @param $a Title
3947          * @param $b Title
3948          *
3949          * @return Integer: result of string comparison, or namespace comparison
3950          */
3951         public static function compare( $a, $b ) {
3952                 if ( $a->getNamespace() == $b->getNamespace() ) {
3953                         return strcmp( $a->getText(), $b->getText() );
3954                 } else {
3955                         return $a->getNamespace() - $b->getNamespace();
3956                 }
3957         }
3958
3959         /**
3960          * Return a string representation of this title
3961          *
3962          * @return String representation of this title
3963          */
3964         public function __toString() {
3965                 return $this->getPrefixedText();
3966         }
3967
3968         /**
3969          * Check if page exists.  For historical reasons, this function simply
3970          * checks for the existence of the title in the page table, and will
3971          * thus return false for interwiki links, special pages and the like.
3972          * If you want to know if a title can be meaningfully viewed, you should
3973          * probably call the isKnown() method instead.
3974          *
3975          * @return Bool
3976          */
3977         public function exists() {
3978                 return $this->getArticleId() != 0;
3979         }
3980
3981         /**
3982          * Should links to this title be shown as potentially viewable (i.e. as
3983          * "bluelinks"), even if there's no record by this title in the page
3984          * table?
3985          *
3986          * This function is semi-deprecated for public use, as well as somewhat
3987          * misleadingly named.  You probably just want to call isKnown(), which
3988          * calls this function internally.
3989          *
3990          * (ISSUE: Most of these checks are cheap, but the file existence check
3991          * can potentially be quite expensive.  Including it here fixes a lot of
3992          * existing code, but we might want to add an optional parameter to skip
3993          * it and any other expensive checks.)
3994          *
3995          * @return Bool
3996          */
3997         public function isAlwaysKnown() {
3998                 if ( $this->mInterwiki != '' ) {
3999                         return true;  // any interwiki link might be viewable, for all we know
4000                 }
4001                 switch( $this->mNamespace ) {
4002                         case NS_MEDIA:
4003                         case NS_FILE:
4004                                 // file exists, possibly in a foreign repo
4005                                 return (bool)wfFindFile( $this );
4006                         case NS_SPECIAL:
4007                                 // valid special page
4008                                 return SpecialPageFactory::exists( $this->getDBkey() );
4009                         case NS_MAIN:
4010                                 // selflink, possibly with fragment
4011                                 return $this->mDbkeyform == '';
4012                         case NS_MEDIAWIKI:
4013                                 // known system message
4014                                 return $this->hasSourceText() !== false;
4015                         default:
4016                                 return false;
4017                 }
4018         }
4019
4020         /**
4021          * Does this title refer to a page that can (or might) be meaningfully
4022          * viewed?  In particular, this function may be used to determine if
4023          * links to the title should be rendered as "bluelinks" (as opposed to
4024          * "redlinks" to non-existent pages).
4025          *
4026          * @return Bool
4027          */
4028         public function isKnown() {
4029                 return $this->isAlwaysKnown() || $this->exists();
4030         }
4031
4032         /**
4033          * Does this page have source text?
4034          *
4035          * @return Boolean
4036          */
4037         public function hasSourceText() {
4038                 if ( $this->exists() ) {
4039                         return true;
4040                 }
4041
4042                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4043                         // If the page doesn't exist but is a known system message, default
4044                         // message content will be displayed, same for language subpages-
4045                         // Use always content language to avoid loading hundreds of languages
4046                         // to get the link color.
4047                         global $wgContLang;
4048                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4049                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4050                         return $message->exists();
4051                 }
4052
4053                 return false;
4054         }
4055
4056         /**
4057          * Get the default message text or false if the message doesn't exist
4058          *
4059          * @return String or false
4060          */
4061         public function getDefaultMessageText() {
4062                 global $wgContLang;
4063
4064                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4065                         return false;
4066                 }
4067
4068                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4069                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4070
4071                 if ( $message->exists() ) {
4072                         return $message->plain();
4073                 } else {
4074                         return false;
4075                 }
4076         }
4077
4078         /**
4079          * Is this in a namespace that allows actual pages?
4080          *
4081          * @return Bool
4082          * @internal note -- uses hardcoded namespace index instead of constants
4083          */
4084         public function canExist() {
4085                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
4086         }
4087
4088         /**
4089          * Update page_touched timestamps and send squid purge messages for
4090          * pages linking to this title. May be sent to the job queue depending
4091          * on the number of links. Typically called on create and delete.
4092          */
4093         public function touchLinks() {
4094                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4095                 $u->doUpdate();
4096
4097                 if ( $this->getNamespace() == NS_CATEGORY ) {
4098                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4099                         $u->doUpdate();
4100                 }
4101         }
4102
4103         /**
4104          * Get the last touched timestamp
4105          *
4106          * @param $db DatabaseBase: optional db
4107          * @return String last-touched timestamp
4108          */
4109         public function getTouched( $db = null ) {
4110                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4111                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4112                 return $touched;
4113         }
4114
4115         /**
4116          * Get the timestamp when this page was updated since the user last saw it.
4117          *
4118          * @param $user User
4119          * @return String|Null
4120          */
4121         public function getNotificationTimestamp( $user = null ) {
4122                 global $wgUser, $wgShowUpdatedMarker;
4123                 // Assume current user if none given
4124                 if ( !$user ) {
4125                         $user = $wgUser;
4126                 }
4127                 // Check cache first
4128                 $uid = $user->getId();
4129                 // avoid isset here, as it'll return false for null entries
4130                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4131                         return $this->mNotificationTimestamp[$uid];
4132                 }
4133                 if ( !$uid || !$wgShowUpdatedMarker ) {
4134                         return $this->mNotificationTimestamp[$uid] = false;
4135                 }
4136                 // Don't cache too much!
4137                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4138                         $this->mNotificationTimestamp = array();
4139                 }
4140                 $dbr = wfGetDB( DB_SLAVE );
4141                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4142                         'wl_notificationtimestamp',
4143                         array( 'wl_namespace' => $this->getNamespace(),
4144                                 'wl_title' => $this->getDBkey(),
4145                                 'wl_user' => $user->getId()
4146                         ),
4147                         __METHOD__
4148                 );
4149                 return $this->mNotificationTimestamp[$uid];
4150         }
4151
4152         /**
4153          * Generate strings used for xml 'id' names in monobook tabs
4154          *
4155          * @param $prepend string defaults to 'nstab-'
4156          * @return String XML 'id' name
4157          */
4158         public function getNamespaceKey( $prepend = 'nstab-' ) {
4159                 global $wgContLang;
4160                 // Gets the subject namespace if this title
4161                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4162                 // Checks if cononical namespace name exists for namespace
4163                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4164                         // Uses canonical namespace name
4165                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4166                 } else {
4167                         // Uses text of namespace
4168                         $namespaceKey = $this->getSubjectNsText();
4169                 }
4170                 // Makes namespace key lowercase
4171                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4172                 // Uses main
4173                 if ( $namespaceKey == '' ) {
4174                         $namespaceKey = 'main';
4175                 }
4176                 // Changes file to image for backwards compatibility
4177                 if ( $namespaceKey == 'file' ) {
4178                         $namespaceKey = 'image';
4179                 }
4180                 return $prepend . $namespaceKey;
4181         }
4182
4183         /**
4184          * Returns true if this is a special page.
4185          *
4186          * @return boolean
4187          */
4188         public function isSpecialPage() {
4189                 return $this->getNamespace() == NS_SPECIAL;
4190         }
4191
4192         /**
4193          * Returns true if this title resolves to the named special page
4194          *
4195          * @param $name String The special page name
4196          * @return boolean
4197          */
4198         public function isSpecial( $name ) {
4199                 if ( $this->isSpecialPage() ) {
4200                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4201                         if ( $name == $thisName ) {
4202                                 return true;
4203                         }
4204                 }
4205                 return false;
4206         }
4207
4208         /**
4209          * If the Title refers to a special page alias which is not the local default, resolve
4210          * the alias, and localise the name as necessary.  Otherwise, return $this
4211          *
4212          * @return Title
4213          */
4214         public function fixSpecialName() {
4215                 if ( $this->isSpecialPage() ) {
4216                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4217                         if ( $canonicalName ) {
4218                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
4219                                 if ( $localName != $this->mDbkeyform ) {
4220                                         return Title::makeTitle( NS_SPECIAL, $localName );
4221                                 }
4222                         }
4223                 }
4224                 return $this;
4225         }
4226
4227         /**
4228          * Is this Title in a namespace which contains content?
4229          * In other words, is this a content page, for the purposes of calculating
4230          * statistics, etc?
4231          *
4232          * @return Boolean
4233          */
4234         public function isContentPage() {
4235                 return MWNamespace::isContent( $this->getNamespace() );
4236         }
4237
4238         /**
4239          * Get all extant redirects to this Title
4240          *
4241          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4242          * @return Array of Title redirects to this title
4243          */
4244         public function getRedirectsHere( $ns = null ) {
4245                 $redirs = array();
4246
4247                 $dbr = wfGetDB( DB_SLAVE );
4248                 $where = array(
4249                         'rd_namespace' => $this->getNamespace(),
4250                         'rd_title' => $this->getDBkey(),
4251                         'rd_from = page_id'
4252                 );
4253                 if ( !is_null( $ns ) ) {
4254                         $where['page_namespace'] = $ns;
4255                 }
4256
4257                 $res = $dbr->select(
4258                         array( 'redirect', 'page' ),
4259                         array( 'page_namespace', 'page_title' ),
4260                         $where,
4261                         __METHOD__
4262                 );
4263
4264                 foreach ( $res as $row ) {
4265                         $redirs[] = self::newFromRow( $row );
4266                 }
4267                 return $redirs;
4268         }
4269
4270         /**
4271          * Check if this Title is a valid redirect target
4272          *
4273          * @return Bool
4274          */
4275         public function isValidRedirectTarget() {
4276                 global $wgInvalidRedirectTargets;
4277
4278                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4279                 if ( $this->isSpecial( 'Userlogout' ) ) {
4280                         return false;
4281                 }
4282
4283                 foreach ( $wgInvalidRedirectTargets as $target ) {
4284                         if ( $this->isSpecial( $target ) ) {
4285                                 return false;
4286                         }
4287                 }
4288
4289                 return true;
4290         }
4291
4292         /**
4293          * Get a backlink cache object
4294          *
4295          * @return BacklinkCache
4296          */
4297         function getBacklinkCache() {
4298                 if ( is_null( $this->mBacklinkCache ) ) {
4299                         $this->mBacklinkCache = new BacklinkCache( $this );
4300                 }
4301                 return $this->mBacklinkCache;
4302         }
4303
4304         /**
4305          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4306          *
4307          * @return Boolean
4308          */
4309         public function canUseNoindex() {
4310                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4311
4312                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4313                         ? $wgContentNamespaces
4314                         : $wgExemptFromUserRobotsControl;
4315
4316                 return !in_array( $this->mNamespace, $bannedNamespaces );
4317
4318         }
4319
4320         /**
4321          * Returns restriction types for the current Title
4322          *
4323          * @return array applicable restriction types
4324          */
4325         public function getRestrictionTypes() {
4326                 if ( $this->isSpecialPage() ) {
4327                         return array();
4328                 }
4329
4330                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4331
4332                 if ( $this->getNamespace() != NS_FILE ) {
4333                         # Remove the upload restriction for non-file titles
4334                         $types = array_diff( $types, array( 'upload' ) );
4335                 }
4336
4337                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4338
4339                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
4340                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
4341
4342                 return $types;
4343         }
4344         /**
4345          * Get a filtered list of all restriction types supported by this wiki.
4346          * @param bool $exists True to get all restriction types that apply to
4347          * titles that do exist, False for all restriction types that apply to
4348          * titles that do not exist
4349          * @return array
4350          */
4351         public static function getFilteredRestrictionTypes( $exists = true ) {
4352                 global $wgRestrictionTypes;
4353                 $types = $wgRestrictionTypes;
4354                 if ( $exists ) {
4355                         # Remove the create restriction for existing titles
4356                         $types = array_diff( $types, array( 'create' ) );
4357                 } else {
4358                         # Only the create and upload restrictions apply to non-existing titles
4359                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4360                 }
4361                 return $types;
4362         }
4363
4364         /**
4365          * Returns the raw sort key to be used for categories, with the specified
4366          * prefix.  This will be fed to Collation::getSortKey() to get a
4367          * binary sortkey that can be used for actual sorting.
4368          *
4369          * @param $prefix string The prefix to be used, specified using
4370          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4371          *   prefix.
4372          * @return string
4373          */
4374         public function getCategorySortkey( $prefix = '' ) {
4375                 $unprefixed = $this->getText();
4376
4377                 // Anything that uses this hook should only depend
4378                 // on the Title object passed in, and should probably
4379                 // tell the users to run updateCollations.php --force
4380                 // in order to re-sort existing category relations.
4381                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4382                 if ( $prefix !== '' ) {
4383                         # Separate with a line feed, so the unprefixed part is only used as
4384                         # a tiebreaker when two pages have the exact same prefix.
4385                         # In UCA, tab is the only character that can sort above LF
4386                         # so we strip both of them from the original prefix.
4387                         $prefix = strtr( $prefix, "\n\t", '  ' );
4388                         return "$prefix\n$unprefixed";
4389                 }
4390                 return $unprefixed;
4391         }
4392
4393         /**
4394          * Get the language in which the content of this page is written.
4395          * Defaults to $wgContLang, but in certain cases it can be e.g.
4396          * $wgLang (such as special pages, which are in the user language).
4397          *
4398          * @since 1.18
4399          * @return object Language
4400          */
4401         public function getPageLanguage() {
4402                 global $wgLang;
4403                 if ( $this->isSpecialPage() ) {
4404                         // special pages are in the user language
4405                         return $wgLang;
4406                 } elseif ( $this->isCssOrJsPage() ) {
4407                         // css/js should always be LTR and is, in fact, English
4408                         return wfGetLangObj( 'en' );
4409                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4410                         // Parse mediawiki messages with correct target language
4411                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4412                         return wfGetLangObj( $lang );
4413                 }
4414                 global $wgContLang;
4415                 // If nothing special, it should be in the wiki content language
4416                 $pageLang = $wgContLang;
4417                 // Hook at the end because we don't want to override the above stuff
4418                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4419                 return wfGetLangObj( $pageLang );
4420         }
4421 }