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 $mCounter = -1;               // /< Number of times this page has been viewed (-1 means "not loaded")
  67         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  68         var $mOldRestrictions = false;
  69         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  70         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  71         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  72         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  73         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  74         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  75         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  76         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  77         # Don't change the following default, NS_MAIN is hardcoded in several
  78         # places.  See bug 696.
  79         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  80                                                                           # Zero except in {{transclusion}} tags
  81         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  82         var $mLength = -1;                // /< The page length, 0 for special pages
  83         var $mRedirect = null;            // /< Is the article at this title a redirect?
  84         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  85         var $mBacklinkCache = null;       // /< Cache of links to this title
  86         // @}
  87
  88
  89         /**
  90          * Constructor
  91          */
  92         /*protected*/ function __construct() { }
  93
  94         /**
  95          * Create a new Title from a prefixed DB key
  96          *
  97          * @param $key String the database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return Title, or NULL on an error
 101          */
 102         public static function newFromDBkey( $key ) {
 103                 $t = new Title();
 104                 $t->mDbkeyform = $key;
 105                 if ( $t->secureAndSplit() ) {
 106                         return $t;
 107                 } else {
 108                         return null;
 109                 }
 110         }
 111
 112         /**
 113          * Create a new Title from text, such as what one would find in a link. De-
 114          * codes any HTML entities in the text.
 115          *
 116          * @param $text String the link text; spaces, prefixes, and an
 117          *   initial ':' indicating the main namespace are accepted.
 118          * @param $defaultNamespace Int the namespace to use if none is speci-
 119          *   fied by a prefix.  If you want to force a specific namespace even if
 120          *   $text might begin with a namespace prefix, use makeTitle() or
 121          *   makeTitleSafe().
 122          * @return Title, or null on an error.
 123          */
 124         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 125                 if ( is_object( $text ) ) {
 126                         throw new MWException( 'Title::newFromText given an object' );
 127                 }
 128
 129                 /**
 130                  * Wiki pages often contain multiple links to the same page.
 131                  * Title normalization and parsing can become expensive on
 132                  * pages with many links, so we can save a little time by
 133                  * caching them.
 134                  *
 135                  * In theory these are value objects and won't get changed...
 136                  */
 137                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 138                         return Title::$titleCache[$text];
 139                 }
 140
 141                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 142                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 143
 144                 $t = new Title();
 145                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 146                 $t->mDefaultNamespace = $defaultNamespace;
 147
 148                 static $cachedcount = 0 ;
 149                 if ( $t->secureAndSplit() ) {
 150                         if ( $defaultNamespace == NS_MAIN ) {
 151                                 if ( $cachedcount >= self::CACHE_MAX ) {
 152                                         # Avoid memory leaks on mass operations...
 153                                         Title::$titleCache = array();
 154                                         $cachedcount = 0;
 155                                 }
 156                                 $cachedcount++;
 157                                 Title::$titleCache[$text] =& $t;
 158                         }
 159                         return $t;
 160                 } else {
 161                         $ret = null;
 162                         return $ret;
 163                 }
 164         }
 165
 166         /**
 167          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 168          *
 169          * Example of wrong and broken code:
 170          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 171          *
 172          * Example of right code:
 173          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Create a new Title from URL-encoded text. Ensures that
 176          * the given title's length does not exceed the maximum.
 177          *
 178          * @param $url String the title, as might be taken from a URL
 179          * @return Title the new object, or NULL on an error
 180          */
 181         public static function newFromURL( $url ) {
 182                 global $wgLegalTitleChars;
 183                 $t = new Title();
 184
 185                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 186                 # but some URLs used it as a space replacement and they still come
 187                 # from some external search tools.
 188                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 189                         $url = str_replace( '+', ' ', $url );
 190                 }
 191
 192                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 193                 if ( $t->secureAndSplit() ) {
 194                         return $t;
 195                 } else {
 196                         return null;
 197                 }
 198         }
 199
 200         /**
 201          * Create a new Title from an article ID
 202          *
 203          * @param $id Int the page_id corresponding to the Title to create
 204          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 205          * @return Title the new object, or NULL on an error
 206          */
 207         public static function newFromID( $id, $flags = 0 ) {
 208                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 209                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 210                 if ( $row !== false ) {
 211                         $title = Title::newFromRow( $row );
 212                 } else {
 213                         $title = null;
 214                 }
 215                 return $title;
 216         }
 217
 218         /**
 219          * Make an array of titles from an array of IDs
 220          *
 221          * @param $ids Array of Int Array of IDs
 222          * @return Array of Titles
 223          */
 224         public static function newFromIDs( $ids ) {
 225                 if ( !count( $ids ) ) {
 226                         return array();
 227                 }
 228                 $dbr = wfGetDB( DB_SLAVE );
 229
 230                 $res = $dbr->select(
 231                         'page',
 232                         array(
 233                                 'page_namespace', 'page_title', 'page_id',
 234                                 'page_len', 'page_is_redirect', 'page_latest',
 235                         ),
 236                         array( 'page_id' => $ids ),
 237                         __METHOD__
 238                 );
 239
 240                 $titles = array();
 241                 foreach ( $res as $row ) {
 242                         $titles[] = Title::newFromRow( $row );
 243                 }
 244                 return $titles;
 245         }
 246
 247         /**
 248          * Make a Title object from a DB row
 249          *
 250          * @param $row Object database row (needs at least page_title,page_namespace)
 251          * @return Title corresponding Title
 252          */
 253         public static function newFromRow( $row ) {
 254                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 255                 $t->loadFromRow( $row );
 256                 return $t;
 257         }
 258
 259         /**
 260          * Load Title object fields from a DB row.
 261          * If false is given, the title will be treated as non-existing.
 262          *
 263          * @param $row Object|false database row
 264          * @return void
 265          */
 266         public function loadFromRow( $row ) {
 267                 if ( $row ) { // page found
 268                         if ( isset( $row->page_id ) )
 269                                 $this->mArticleID = (int)$row->page_id;
 270                         if ( isset( $row->page_len ) )
 271                                 $this->mLength = (int)$row->page_len;
 272                         if ( isset( $row->page_is_redirect ) )
 273                                 $this->mRedirect = (bool)$row->page_is_redirect;
 274                         if ( isset( $row->page_latest ) )
 275                                 $this->mLatestID = (int)$row->page_latest;
 276                         if ( isset( $row->page_counter ) )
 277                                 $this->mCounter = (int)$row->page_counter;
 278                 } else { // page not found
 279                         $this->mArticleID = 0;
 280                         $this->mLength = 0;
 281                         $this->mRedirect = false;
 282                         $this->mLatestID = 0;
 283                         $this->mCounter = 0;
 284                 }
 285         }
 286
 287         /**
 288          * Create a new Title from a namespace index and a DB key.
 289          * It's assumed that $ns and $title are *valid*, for instance when
 290          * they came directly from the database or a special page name.
 291          * For convenience, spaces are converted to underscores so that
 292          * eg user_text fields can be used directly.
 293          *
 294          * @param $ns Int the namespace of the article
 295          * @param $title String the unprefixed database key form
 296          * @param $fragment String the link fragment (after the "#")
 297          * @param $interwiki String the interwiki prefix
 298          * @return Title the new object
 299          */
 300         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 301                 $t = new Title();
 302                 $t->mInterwiki = $interwiki;
 303                 $t->mFragment = $fragment;
 304                 $t->mNamespace = $ns = intval( $ns );
 305                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 306                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 307                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 308                 $t->mTextform = str_replace( '_', ' ', $title );
 309                 return $t;
 310         }
 311
 312         /**
 313          * Create a new Title from a namespace index and a DB key.
 314          * The parameters will be checked for validity, which is a bit slower
 315          * than makeTitle() but safer for user-provided data.
 316          *
 317          * @param $ns Int the namespace of the article
 318          * @param $title String database key form
 319          * @param $fragment String the link fragment (after the "#")
 320          * @param $interwiki String interwiki prefix
 321          * @return Title the new object, or NULL on an error
 322          */
 323         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 324                 $t = new Title();
 325                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 326                 if ( $t->secureAndSplit() ) {
 327                         return $t;
 328                 } else {
 329                         return null;
 330                 }
 331         }
 332
 333         /**
 334          * Create a new Title for the Main Page
 335          *
 336          * @return Title the new object
 337          */
 338         public static function newMainPage() {
 339                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 340                 // Don't give fatal errors if the message is broken
 341                 if ( !$title ) {
 342                         $title = Title::newFromText( 'Main Page' );
 343                 }
 344                 return $title;
 345         }
 346
 347         /**
 348          * Extract a redirect destination from a string and return the
 349          * Title, or null if the text doesn't contain a valid redirect
 350          * This will only return the very next target, useful for
 351          * the redirect table and other checks that don't need full recursion
 352          *
 353          * @param $text String: Text with possible redirect
 354          * @return Title: The corresponding Title
 355          */
 356         public static function newFromRedirect( $text ) {
 357                 return self::newFromRedirectInternal( $text );
 358         }
 359
 360         /**
 361          * Extract a redirect destination from a string and return the
 362          * Title, or null if the text doesn't contain a valid redirect
 363          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 364          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 365          *
 366          * @param $text String Text with possible redirect
 367          * @return Title
 368          */
 369         public static function newFromRedirectRecurse( $text ) {
 370                 $titles = self::newFromRedirectArray( $text );
 371                 return $titles ? array_pop( $titles ) : null;
 372         }
 373
 374         /**
 375          * Extract a redirect destination from a string and return an
 376          * array of Titles, or null if the text doesn't contain a valid redirect
 377          * The last element in the array is the final destination after all redirects
 378          * have been resolved (up to $wgMaxRedirects times)
 379          *
 380          * @param $text String Text with possible redirect
 381          * @return Array of Titles, with the destination last
 382          */
 383         public static function newFromRedirectArray( $text ) {
 384                 global $wgMaxRedirects;
 385                 $title = self::newFromRedirectInternal( $text );
 386                 if ( is_null( $title ) ) {
 387                         return null;
 388                 }
 389                 // recursive check to follow double redirects
 390                 $recurse = $wgMaxRedirects;
 391                 $titles = array( $title );
 392                 while ( --$recurse > 0 ) {
 393                         if ( $title->isRedirect() ) {
 394                                 $page = WikiPage::factory( $title );
 395                                 $newtitle = $page->getRedirectTarget();
 396                         } else {
 397                                 break;
 398                         }
 399                         // Redirects to some special pages are not permitted
 400                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 401                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 402                                 $title = $newtitle;
 403                                 $titles[] = $newtitle;
 404                         } else {
 405                                 break;
 406                         }
 407                 }
 408                 return $titles;
 409         }
 410
 411         /**
 412          * Really extract the redirect destination
 413          * Do not call this function directly, use one of the newFromRedirect* functions above
 414          *
 415          * @param $text String Text with possible redirect
 416          * @return Title
 417          */
 418         protected static function newFromRedirectInternal( $text ) {
 419                 global $wgMaxRedirects;
 420                 if ( $wgMaxRedirects < 1 ) {
 421                         //redirects are disabled, so quit early
 422                         return null;
 423                 }
 424                 $redir = MagicWord::get( 'redirect' );
 425                 $text = trim( $text );
 426                 if ( $redir->matchStartAndRemove( $text ) ) {
 427                         // Extract the first link and see if it's usable
 428                         // Ensure that it really does come directly after #REDIRECT
 429                         // Some older redirects included a colon, so don't freak about that!
 430                         $m = array();
 431                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 432                                 // Strip preceding colon used to "escape" categories, etc.
 433                                 // and URL-decode links
 434                                 if ( strpos( $m[1], '%' ) !== false ) {
 435                                         // Match behavior of inline link parsing here;
 436                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 437                                 }
 438                                 $title = Title::newFromText( $m[1] );
 439                                 // If the title is a redirect to bad special pages or is invalid, return null
 440                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 441                                         return null;
 442                                 }
 443                                 return $title;
 444                         }
 445                 }
 446                 return null;
 447         }
 448
 449         /**
 450          * Get the prefixed DB key associated with an ID
 451          *
 452          * @param $id Int the page_id of the article
 453          * @return Title an object representing the article, or NULL if no such article was found
 454          */
 455         public static function nameOf( $id ) {
 456                 $dbr = wfGetDB( DB_SLAVE );
 457
 458                 $s = $dbr->selectRow(
 459                         'page',
 460                         array( 'page_namespace', 'page_title' ),
 461                         array( 'page_id' => $id ),
 462                         __METHOD__
 463                 );
 464                 if ( $s === false ) {
 465                         return null;
 466                 }
 467
 468                 $n = self::makeName( $s->page_namespace, $s->page_title );
 469                 return $n;
 470         }
 471
 472         /**
 473          * Get a regex character class describing the legal characters in a link
 474          *
 475          * @return String the list of characters, not delimited
 476          */
 477         public static function legalChars() {
 478                 global $wgLegalTitleChars;
 479                 return $wgLegalTitleChars;
 480         }
 481
 482         /**
 483          * Get a string representation of a title suitable for
 484          * including in a search index
 485          *
 486          * @param $ns Int a namespace index
 487          * @param $title String text-form main part
 488          * @return String a stripped-down title string ready for the search index
 489          */
 490         public static function indexTitle( $ns, $title ) {
 491                 global $wgContLang;
 492
 493                 $lc = SearchEngine::legalSearchChars() . '&#;';
 494                 $t = $wgContLang->normalizeForSearch( $title );
 495                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 496                 $t = $wgContLang->lc( $t );
 497
 498                 # Handle 's, s'
 499                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 500                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 501
 502                 $t = preg_replace( "/\\s+/", ' ', $t );
 503
 504                 if ( $ns == NS_FILE ) {
 505                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 506                 }
 507                 return trim( $t );
 508         }
 509
 510         /**
 511          * Make a prefixed DB key from a DB key and a namespace index
 512          *
 513          * @param $ns Int numerical representation of the namespace
 514          * @param $title String the DB key form the title
 515          * @param $fragment String The link fragment (after the "#")
 516          * @param $interwiki String The interwiki prefix
 517          * @return String the prefixed form of the title
 518          */
 519         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 520                 global $wgContLang;
 521
 522                 $namespace = $wgContLang->getNsText( $ns );
 523                 $name = $namespace == '' ? $title : "$namespace:$title";
 524                 if ( strval( $interwiki ) != '' ) {
 525                         $name = "$interwiki:$name";
 526                 }
 527                 if ( strval( $fragment ) != '' ) {
 528                         $name .= '#' . $fragment;
 529                 }
 530                 return $name;
 531         }
 532
 533         /**
 534          * Escape a text fragment, say from a link, for a URL
 535          *
 536          * @param $fragment string containing a URL or link fragment (after the "#")
 537          * @return String: escaped string
 538          */
 539         static function escapeFragmentForURL( $fragment ) {
 540                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 541                 # fragments appear not to work in IE (at least up to 7) or in at least
 542                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 543                 # to care if they aren't encoded.
 544                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 545         }
 546
 547         /**
 548          * Determine whether the object refers to a page within
 549          * this project.
 550          *
 551          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 552          */
 553         public function isLocal() {
 554                 if ( $this->mInterwiki != '' ) {
 555                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 556                 } else {
 557                         return true;
 558                 }
 559         }
 560
 561         /**
 562          * Is this Title interwiki?
 563          *
 564          * @return Bool
 565          */
 566         public function isExternal() {
 567                 return ( $this->mInterwiki != '' );
 568         }
 569
 570         /**
 571          * Get the interwiki prefix (or null string)
 572          *
 573          * @return String Interwiki prefix
 574          */
 575         public function getInterwiki() {
 576                 return $this->mInterwiki;
 577         }
 578
 579         /**
 580          * Determine whether the object refers to a page within
 581          * this project and is transcludable.
 582          *
 583          * @return Bool TRUE if this is transcludable
 584          */
 585         public function isTrans() {
 586                 if ( $this->mInterwiki == '' ) {
 587                         return false;
 588                 }
 589
 590                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 591         }
 592
 593         /**
 594          * Returns the DB name of the distant wiki which owns the object.
 595          *
 596          * @return String the DB name
 597          */
 598         public function getTransWikiID() {
 599                 if ( $this->mInterwiki == '' ) {
 600                         return false;
 601                 }
 602
 603                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 604         }
 605
 606         /**
 607          * Get the text form (spaces not underscores) of the main part
 608          *
 609          * @return String Main part of the title
 610          */
 611         public function getText() {
 612                 return $this->mTextform;
 613         }
 614
 615         /**
 616          * Get the URL-encoded form of the main part
 617          *
 618          * @return String Main part of the title, URL-encoded
 619          */
 620         public function getPartialURL() {
 621                 return $this->mUrlform;
 622         }
 623
 624         /**
 625          * Get the main part with underscores
 626          *
 627          * @return String: Main part of the title, with underscores
 628          */
 629         public function getDBkey() {
 630                 return $this->mDbkeyform;
 631         }
 632
 633         /**
 634          * Get the namespace index, i.e. one of the NS_xxxx constants.
 635          *
 636          * @return Integer: Namespace index
 637          */
 638         public function getNamespace() {
 639                 return $this->mNamespace;
 640         }
 641
 642         /**
 643          * Get the namespace text
 644          *
 645          * @return String: Namespace text
 646          */
 647         public function getNsText() {
 648                 global $wgContLang;
 649
 650                 if ( $this->mInterwiki != '' ) {
 651                         // This probably shouldn't even happen. ohh man, oh yuck.
 652                         // But for interwiki transclusion it sometimes does.
 653                         // Shit. Shit shit shit.
 654                         //
 655                         // Use the canonical namespaces if possible to try to
 656                         // resolve a foreign namespace.
 657                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 658                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 659                         }
 660                 }
 661
 662                 // Strip off subpages
 663                 $pagename = $this->getText();
 664                 if ( strpos( $pagename, '/' ) !== false ) {
 665                         list( $username , ) = explode( '/', $pagename, 2 );
 666                 } else {
 667                         $username = $pagename;
 668                 }
 669
 670                 if ( $wgContLang->needsGenderDistinction() &&
 671                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 672                         $gender = GenderCache::singleton()->getGenderOf( $username, __METHOD__ );
 673                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 674                 }
 675
 676                 return $wgContLang->getNsText( $this->mNamespace );
 677         }
 678
 679         /**
 680          * Get the DB key with the initial letter case as specified by the user
 681          *
 682          * @return String DB key
 683          */
 684         function getUserCaseDBKey() {
 685                 return $this->mUserCaseDBKey;
 686         }
 687
 688         /**
 689          * Get the namespace text of the subject (rather than talk) page
 690          *
 691          * @return String Namespace text
 692          */
 693         public function getSubjectNsText() {
 694                 global $wgContLang;
 695                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 696         }
 697
 698         /**
 699          * Get the namespace text of the talk page
 700          *
 701          * @return String Namespace text
 702          */
 703         public function getTalkNsText() {
 704                 global $wgContLang;
 705                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 706         }
 707
 708         /**
 709          * Could this title have a corresponding talk page?
 710          *
 711          * @return Bool TRUE or FALSE
 712          */
 713         public function canTalk() {
 714                 return( MWNamespace::canTalk( $this->mNamespace ) );
 715         }
 716
 717         /**
 718          * Get the Title fragment (i.e.\ the bit after the #) in text form
 719          *
 720          * @return String Title fragment
 721          */
 722         public function getFragment() { return $this->mFragment; }
 723
 724         /**
 725          * Get the fragment in URL form, including the "#" character if there is one
 726          * @return String Fragment in URL form
 727          */
 728         public function getFragmentForURL() {
 729                 if ( $this->mFragment == '' ) {
 730                         return '';
 731                 } else {
 732                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 733                 }
 734         }
 735
 736         /**
 737          * Get the default namespace index, for when there is no namespace
 738          *
 739          * @return Int Default namespace index
 740          */
 741         public function getDefaultNamespace() {
 742                 return $this->mDefaultNamespace;
 743         }
 744
 745         /**
 746          * Get title for search index
 747          *
 748          * @return String a stripped-down title string ready for the
 749          *  search index
 750          */
 751         public function getIndexTitle() {
 752                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 753         }
 754
 755         /**
 756          * Get the prefixed database key form
 757          *
 758          * @return String the prefixed title, with underscores and
 759          *  any interwiki and namespace prefixes
 760          */
 761         public function getPrefixedDBkey() {
 762                 $s = $this->prefix( $this->mDbkeyform );
 763                 $s = str_replace( ' ', '_', $s );
 764                 return $s;
 765         }
 766
 767         /**
 768          * Get the prefixed title with spaces.
 769          * This is the form usually used for display
 770          *
 771          * @return String the prefixed title, with spaces
 772          */
 773         public function getPrefixedText() {
 774                 // @todo FIXME: Bad usage of empty() ?
 775                 if ( empty( $this->mPrefixedText ) ) {
 776                         $s = $this->prefix( $this->mTextform );
 777                         $s = str_replace( '_', ' ', $s );
 778                         $this->mPrefixedText = $s;
 779                 }
 780                 return $this->mPrefixedText;
 781         }
 782
 783         /**
 784         /**
 785          * Get the prefixed title with spaces, plus any fragment
 786          * (part beginning with '#')
 787          *
 788          * @return String the prefixed title, with spaces and the fragment, including '#'
 789          */
 790         public function getFullText() {
 791                 $text = $this->getPrefixedText();
 792                 if ( $this->mFragment != '' ) {
 793                         $text .= '#' . $this->mFragment;
 794                 }
 795                 return $text;
 796         }
 797
 798         /**
 799          * Get the base page name, i.e. the leftmost part before any slashes
 800          *
 801          * @return String Base name
 802          */
 803         public function getBaseText() {
 804                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 805                         return $this->getText();
 806                 }
 807
 808                 $parts = explode( '/', $this->getText() );
 809                 # Don't discard the real title if there's no subpage involved
 810                 if ( count( $parts ) > 1 ) {
 811                         unset( $parts[count( $parts ) - 1] );
 812                 }
 813                 return implode( '/', $parts );
 814         }
 815
 816         /**
 817          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
 818          *
 819          * @return String Subpage name
 820          */
 821         public function getSubpageText() {
 822                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 823                         return( $this->mTextform );
 824                 }
 825                 $parts = explode( '/', $this->mTextform );
 826                 return( $parts[count( $parts ) - 1] );
 827         }
 828
 829         /**
 830          * Get the HTML-escaped displayable text form.
 831          * Used for the title field in <a> tags.
 832          *
 833          * @return String the text, including any prefixes
 834          */
 835         public function getEscapedText() {
 836                 return htmlspecialchars( $this->getPrefixedText() );
 837         }
 838
 839         /**
 840          * Get a URL-encoded form of the subpage text
 841          *
 842          * @return String URL-encoded subpage name
 843          */
 844         public function getSubpageUrlForm() {
 845                 $text = $this->getSubpageText();
 846                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 847                 return( $text );
 848         }
 849
 850         /**
 851          * Get a URL-encoded title (not an actual URL) including interwiki
 852          *
 853          * @return String the URL-encoded form
 854          */
 855         public function getPrefixedURL() {
 856                 $s = $this->prefix( $this->mDbkeyform );
 857                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 858                 return $s;
 859         }
 860
 861         /**
 862          * Get a real URL referring to this title, with interwiki link and
 863          * fragment
 864          *
 865          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 866          *   links. Can be specified as an associative array as well, e.g.,
 867          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 868          * @param $variant String language variant of url (for sr, zh..)
 869          * @return String the URL
 870          */
 871         public function getFullURL( $query = '', $variant = false ) {
 872                 # Hand off all the decisions on urls to getLocalURL
 873                 $url = $this->getLocalURL( $query, $variant );
 874
 875                 # Expand the url to make it a full url. Note that getLocalURL has the
 876                 # potential to output full urls for a variety of reasons, so we use
 877                 # wfExpandUrl instead of simply prepending $wgServer
 878                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
 879
 880                 # Finally, add the fragment.
 881                 $url .= $this->getFragmentForURL();
 882
 883                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query, $variant ) );
 884                 return $url;
 885         }
 886
 887         /**
 888          * Get a URL with no fragment or server name.  If this page is generated
 889          * with action=render, $wgServer is prepended.
 890          *
 891          * @param $query Mixed: an optional query string; if not specified,
 892          *   $wgArticlePath will be used.  Can be specified as an associative array
 893          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 894          *   URL-escaped).
 895          * @param $variant String language variant of url (for sr, zh..)
 896          * @return String the URL
 897          */
 898         public function getLocalURL( $query = '', $variant = false ) {
 899                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 900                 global $wgVariantArticlePath;
 901
 902                 if ( is_array( $query ) ) {
 903                         $query = wfArrayToCGI( $query );
 904                 }
 905
 906                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 907                 if ( $interwiki ) {
 908                         $namespace = $this->getNsText();
 909                         if ( $namespace != '' ) {
 910                                 # Can this actually happen? Interwikis shouldn't be parsed.
 911                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 912                                 $namespace .= ':';
 913                         }
 914                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 915                         $url = wfAppendQuery( $url, $query );
 916                 } else {
 917                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 918                         if ( $query == '' ) {
 919                                 if ( $variant != false && $this->getPageLanguage()->hasVariants() ) {
 920                                         if ( !$wgVariantArticlePath ) {
 921                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 922                                         } else {
 923                                                 $variantArticlePath = $wgVariantArticlePath;
 924                                         }
 925                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 926                                         $url = str_replace( '$1', $dbkey, $url  );
 927                                 } else {
 928                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 929                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
 930                                 }
 931                         } else {
 932                                 global $wgActionPaths;
 933                                 $url = false;
 934                                 $matches = array();
 935                                 if ( !empty( $wgActionPaths ) &&
 936                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 937                                 {
 938                                         $action = urldecode( $matches[2] );
 939                                         if ( isset( $wgActionPaths[$action] ) ) {
 940                                                 $query = $matches[1];
 941                                                 if ( isset( $matches[4] ) ) {
 942                                                         $query .= $matches[4];
 943                                                 }
 944                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 945                                                 if ( $query != '' ) {
 946                                                         $url = wfAppendQuery( $url, $query );
 947                                                 }
 948                                         }
 949                                 }
 950
 951                                 if ( $url === false ) {
 952                                         if ( $query == '-' ) {
 953                                                 $query = '';
 954                                         }
 955                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 956                                 }
 957                         }
 958
 959                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
 960
 961                         // @todo FIXME: This causes breakage in various places when we
 962                         // actually expected a local URL and end up with dupe prefixes.
 963                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 964                                 $url = $wgServer . $url;
 965                         }
 966                 }
 967                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
 968                 return $url;
 969         }
 970
 971         /**
 972          * Get a URL that's the simplest URL that will be valid to link, locally,
 973          * to the current Title.  It includes the fragment, but does not include
 974          * the server unless action=render is used (or the link is external).  If
 975          * there's a fragment but the prefixed text is empty, we just return a link
 976          * to the fragment.
 977          *
 978          * The result obviously should not be URL-escaped, but does need to be
 979          * HTML-escaped if it's being output in HTML.
 980          *
 981          * @param $query Array of Strings An associative array of key => value pairs for the
 982          *   query string.  Keys and values will be escaped.
 983          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 984          *   for external links.  Default is "false" (same variant as current page,
 985          *   for anonymous users).
 986          * @return String the URL
 987          */
 988         public function getLinkURL( $query = array(), $variant = false ) {
 989                 wfProfileIn( __METHOD__ );
 990                 if ( $this->isExternal() ) {
 991                         $ret = $this->getFullURL( $query );
 992                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 993                         $ret = $this->getFragmentForURL();
 994                 } else {
 995                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 996                 }
 997                 wfProfileOut( __METHOD__ );
 998                 return $ret;
 999         }
1000
1001         /**
1002          * Get an HTML-escaped version of the URL form, suitable for
1003          * using in a link, without a server name or fragment
1004          *
1005          * @param $query String an optional query string
1006          * @return String the URL
1007          */
1008         public function escapeLocalURL( $query = '' ) {
1009                 return htmlspecialchars( $this->getLocalURL( $query ) );
1010         }
1011
1012         /**
1013          * Get an HTML-escaped version of the URL form, suitable for
1014          * using in a link, including the server name and fragment
1015          *
1016          * @param $query String an optional query string
1017          * @return String the URL
1018          */
1019         public function escapeFullURL( $query = '' ) {
1020                 return htmlspecialchars( $this->getFullURL( $query ) );
1021         }
1022
1023         /**
1024          * Get the URL form for an internal link.
1025          * - Used in various Squid-related code, in case we have a different
1026          * internal hostname for the server from the exposed one.
1027          *
1028          * This uses $wgInternalServer to qualify the path, or $wgServer
1029          * if $wgInternalServer is not set. If the server variable used is
1030          * protocol-relative, the URL will be expanded to http://
1031          *
1032          * @param $query String an optional query string
1033          * @param $variant String language variant of url (for sr, zh..)
1034          * @return String the URL
1035          */
1036         public function getInternalURL( $query = '', $variant = false ) {
1037                 global $wgInternalServer, $wgServer;
1038                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1039                 $url = wfExpandUrl( $server . $this->getLocalURL( $query, $variant ), PROTO_HTTP );
1040                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query, $variant ) );
1041                 return $url;
1042         }
1043
1044         /**
1045          * Get the URL for a canonical link, for use in things like IRC and
1046          * e-mail notifications. Uses $wgCanonicalServer and the
1047          * GetCanonicalURL hook.
1048          *
1049          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1050          *
1051          * @param $query string An optional query string
1052          * @param $variant string Language variant of URL (for sr, zh, ...)
1053          * @return string The URL
1054          * @since 1.18
1055          */
1056         public function getCanonicalURL( $query = '', $variant = false ) {
1057                 $url = wfExpandUrl( $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1058                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query, $variant ) );
1059                 return $url;
1060         }
1061
1062         /**
1063          * HTML-escaped version of getCanonicalURL()
1064          * @since 1.18
1065          */
1066         public function escapeCanonicalURL( $query = '', $variant = false ) {
1067                 return htmlspecialchars( $this->getCanonicalURL( $query, $variant ) );
1068         }
1069
1070         /**
1071          * Get the edit URL for this Title
1072          *
1073          * @return String the URL, or a null string if this is an
1074          *  interwiki link
1075          */
1076         public function getEditURL() {
1077                 if ( $this->mInterwiki != '' ) {
1078                         return '';
1079                 }
1080                 $s = $this->getLocalURL( 'action=edit' );
1081
1082                 return $s;
1083         }
1084
1085         /**
1086          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1087          *
1088          * @param $action String Action to check (default: edit)
1089          * @return Bool
1090          */
1091         public function isSemiProtected( $action = 'edit' ) {
1092                 if ( $this->exists() ) {
1093                         $restrictions = $this->getRestrictions( $action );
1094                         if ( count( $restrictions ) > 0 ) {
1095                                 foreach ( $restrictions as $restriction ) {
1096                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1097                                                 return false;
1098                                         }
1099                                 }
1100                         } else {
1101                                 # Not protected
1102                                 return false;
1103                         }
1104                         return true;
1105                 } else {
1106                         # If it doesn't exist, it can't be protected
1107                         return false;
1108                 }
1109         }
1110
1111         /**
1112          * Does the title correspond to a protected article?
1113          *
1114          * @param $action String the action the page is protected from,
1115          * by default checks all actions.
1116          * @return Bool
1117          */
1118         public function isProtected( $action = '' ) {
1119                 global $wgRestrictionLevels;
1120
1121                 $restrictionTypes = $this->getRestrictionTypes();
1122
1123                 # Special pages have inherent protection
1124                 if( $this->isSpecialPage() ) {
1125                         return true;
1126                 }
1127
1128                 # Check regular protection levels
1129                 foreach ( $restrictionTypes as $type ) {
1130                         if ( $action == $type || $action == '' ) {
1131                                 $r = $this->getRestrictions( $type );
1132                                 foreach ( $wgRestrictionLevels as $level ) {
1133                                         if ( in_array( $level, $r ) && $level != '' ) {
1134                                                 return true;
1135                                         }
1136                                 }
1137                         }
1138                 }
1139
1140                 return false;
1141         }
1142
1143         /**
1144          * Determines if $user is unable to edit this page because it has been protected
1145          * by $wgNamespaceProtection.
1146          *
1147          * @param $user User object to check permissions
1148          * @return Bool
1149          */
1150         public function isNamespaceProtected( User $user ) {
1151                 global $wgNamespaceProtection;
1152
1153                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1154                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1155                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1156                                         return true;
1157                                 }
1158                         }
1159                 }
1160                 return false;
1161         }
1162
1163         /**
1164          * Is this a conversion table for the LanguageConverter?
1165          *
1166          * @return Bool
1167          */
1168         public function isConversionTable() {
1169                 if(
1170                         $this->getNamespace() == NS_MEDIAWIKI &&
1171                         strpos( $this->getText(), 'Conversiontable' ) !== false
1172                 )
1173                 {
1174                         return true;
1175                 }
1176
1177                 return false;
1178         }
1179
1180         /**
1181          * Is $wgUser watching this page?
1182          *
1183          * @return Bool
1184          */
1185         public function userIsWatching() {
1186                 global $wgUser;
1187
1188                 if ( is_null( $this->mWatched ) ) {
1189                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1190                                 $this->mWatched = false;
1191                         } else {
1192                                 $this->mWatched = $wgUser->isWatched( $this );
1193                         }
1194                 }
1195                 return $this->mWatched;
1196         }
1197
1198         /**
1199          * Can $wgUser read this page?
1200          *
1201          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1202          * @return Bool
1203          * @todo fold these checks into userCan()
1204          */
1205         public function userCanRead() {
1206                 return $this->userCan( 'read' );
1207         }
1208
1209         /**
1210          * Can $wgUser perform $action on this page?
1211          * This skips potentially expensive cascading permission checks
1212          * as well as avoids expensive error formatting
1213          *
1214          * Suitable for use for nonessential UI controls in common cases, but
1215          * _not_ for functional access control.
1216          *
1217          * May provide false positives, but should never provide a false negative.
1218          *
1219          * @param $action String action that permission needs to be checked for
1220          * @param $user User to check (since 1.19)
1221          * @return Bool
1222          */
1223         public function quickUserCan( $action, $user = null ) {
1224                 return $this->userCan( $action, $user, false );
1225         }
1226
1227         /**
1228          * Can $wgUser perform $action on this page?
1229          *
1230          * @param $action String action that permission needs to be checked for
1231          * @param $user User to check (since 1.19)
1232          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1233          * @return Bool
1234          */
1235         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1236                 if ( !$user instanceof User ) {
1237                         global $wgUser;
1238                         $user = $wgUser;
1239                 }
1240                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1241         }
1242
1243         /**
1244          * Can $user perform $action on this page?
1245          *
1246          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1247          *
1248          * @param $action String action that permission needs to be checked for
1249          * @param $user User to check
1250          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1251          *   skipping checks for cascading protections and user blocks.
1252          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1253          * @return Array of arguments to wfMsg to explain permissions problems.
1254          */
1255         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1256                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1257
1258                 // Remove the errors being ignored.
1259                 foreach ( $errors as $index => $error ) {
1260                         $error_key = is_array( $error ) ? $error[0] : $error;
1261
1262                         if ( in_array( $error_key, $ignoreErrors ) ) {
1263                                 unset( $errors[$index] );
1264                         }
1265                 }
1266
1267                 return $errors;
1268         }
1269
1270         /**
1271          * Permissions checks that fail most often, and which are easiest to test.
1272          *
1273          * @param $action String the action to check
1274          * @param $user User user to check
1275          * @param $errors Array list of current errors
1276          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1277          * @param $short Boolean short circuit on first error
1278          *
1279          * @return Array list of errors
1280          */
1281         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1282                 $ns = $this->getNamespace();
1283
1284                 if ( $action == 'create' ) {
1285                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1286                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1287                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1288                         }
1289                 } elseif ( $action == 'move' ) {
1290                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1291                                         && $ns == NS_USER && !$this->isSubpage() ) {
1292                                 // Show user page-specific message only if the user can move other pages
1293                                 $errors[] = array( 'cant-move-user-page' );
1294                         }
1295
1296                         // Check if user is allowed to move files if it's a file
1297                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1298                                 $errors[] = array( 'movenotallowedfile' );
1299                         }
1300
1301                         if ( !$user->isAllowed( 'move', $ns) ) {
1302                                 // User can't move anything
1303
1304                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1305                                         array( 'user' ), $ns ), true );
1306                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1307                                         array( 'autoconfirmed' ), $ns ), true );
1308
1309                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1310                                         // custom message if logged-in users without any special rights can move
1311                                         $errors[] = array( 'movenologintext' );
1312                                 } else {
1313                                         $errors[] = array( 'movenotallowed' );
1314                                 }
1315                         }
1316                 } elseif ( $action == 'move-target' ) {
1317                         if ( !$user->isAllowed( 'move', $ns ) ) {
1318                                 // User can't move anything
1319                                 $errors[] = array( 'movenotallowed' );
1320                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1321                                         && $ns == NS_USER && !$this->isSubpage() ) {
1322                                 // Show user page-specific message only if the user can move other pages
1323                                 $errors[] = array( 'cant-move-to-user-page' );
1324                         }
1325                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1326                         $errors[] = $this->missingPermissionError( $action, $short );
1327                 }
1328
1329                 return $errors;
1330         }
1331
1332         /**
1333          * Add the resulting error code to the errors array
1334          *
1335          * @param $errors Array list of current errors
1336          * @param $result Mixed result of errors
1337          *
1338          * @return Array list of errors
1339          */
1340         private function resultToError( $errors, $result ) {
1341                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1342                         // A single array representing an error
1343                         $errors[] = $result;
1344                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1345                         // A nested array representing multiple errors
1346                         $errors = array_merge( $errors, $result );
1347                 } elseif ( $result !== '' && is_string( $result ) ) {
1348                         // A string representing a message-id
1349                         $errors[] = array( $result );
1350                 } elseif ( $result === false ) {
1351                         // a generic "We don't want them to do that"
1352                         $errors[] = array( 'badaccess-group0' );
1353                 }
1354                 return $errors;
1355         }
1356
1357         /**
1358          * Check various permission hooks
1359          *
1360          * @param $action String the action to check
1361          * @param $user User user to check
1362          * @param $errors Array list of current errors
1363          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1364          * @param $short Boolean short circuit on first error
1365          *
1366          * @return Array list of errors
1367          */
1368         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1369                 // Use getUserPermissionsErrors instead
1370                 $result = '';
1371                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1372                         return $result ? array() : array( array( 'badaccess-group0' ) );
1373                 }
1374                 // Check getUserPermissionsErrors hook
1375                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1376                         $errors = $this->resultToError( $errors, $result );
1377                 }
1378                 // Check getUserPermissionsErrorsExpensive hook
1379                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1380                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1381                         $errors = $this->resultToError( $errors, $result );
1382                 }
1383
1384                 return $errors;
1385         }
1386
1387         /**
1388          * Check permissions on special pages & namespaces
1389          *
1390          * @param $action String the action to check
1391          * @param $user User user to check
1392          * @param $errors Array list of current errors
1393          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1394          * @param $short Boolean short circuit on first error
1395          *
1396          * @return Array list of errors
1397          */
1398         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1399                 # Only 'createaccount' and 'execute' can be performed on
1400                 # special pages, which don't actually exist in the DB.
1401                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1402                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1403                         $errors[] = array( 'ns-specialprotected' );
1404                 }
1405
1406                 # Check $wgNamespaceProtection for restricted namespaces
1407                 if ( $this->isNamespaceProtected( $user ) ) {
1408                         $ns = $this->mNamespace == NS_MAIN ?
1409                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1410                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1411                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1412                 }
1413
1414                 return $errors;
1415         }
1416
1417         /**
1418          * Check CSS/JS sub-page permissions
1419          *
1420          * @param $action String the action to check
1421          * @param $user User user to check
1422          * @param $errors Array list of current errors
1423          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1424          * @param $short Boolean short circuit on first error
1425          *
1426          * @return Array list of errors
1427          */
1428         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1429                 # Protect css/js subpages of user pages
1430                 # XXX: this might be better using restrictions
1431                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1432                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1433                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1434                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1435                                 $errors[] = array( 'customcssprotected' );
1436                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1437                                 $errors[] = array( 'customjsprotected' );
1438                         }
1439                 }
1440
1441                 return $errors;
1442         }
1443
1444         /**
1445          * Check against page_restrictions table requirements on this
1446          * page. The user must possess all required rights for this
1447          * action.
1448          *
1449          * @param $action String the action to check
1450          * @param $user User user to check
1451          * @param $errors Array list of current errors
1452          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1453          * @param $short Boolean short circuit on first error
1454          *
1455          * @return Array list of errors
1456          */
1457         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1458                 foreach ( $this->getRestrictions( $action ) as $right ) {
1459                         // Backwards compatibility, rewrite sysop -> protect
1460                         if ( $right == 'sysop' ) {
1461                                 $right = 'protect';
1462                         }
1463                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1464                                 // Users with 'editprotected' permission can edit protected pages
1465                                 // without cascading option turned on.
1466                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected', $this->mNamespace )
1467                                         || $this->mCascadeRestriction )
1468                                 {
1469                                         $errors[] = array( 'protectedpagetext', $right );
1470                                 }
1471                         }
1472                 }
1473
1474                 return $errors;
1475         }
1476
1477         /**
1478          * Check restrictions on cascading pages.
1479          *
1480          * @param $action String the action to check
1481          * @param $user User to check
1482          * @param $errors Array list of current errors
1483          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1484          * @param $short Boolean short circuit on first error
1485          *
1486          * @return Array list of errors
1487          */
1488         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1489                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1490                         # We /could/ use the protection level on the source page, but it's
1491                         # fairly ugly as we have to establish a precedence hierarchy for pages
1492                         # included by multiple cascade-protected pages. So just restrict
1493                         # it to people with 'protect' permission, as they could remove the
1494                         # protection anyway.
1495                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1496                         # Cascading protection depends on more than this page...
1497                         # Several cascading protected pages may include this page...
1498                         # Check each cascading level
1499                         # This is only for protection restrictions, not for all actions
1500                         if ( isset( $restrictions[$action] ) ) {
1501                                 foreach ( $restrictions[$action] as $right ) {
1502                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1503                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1504                                                 $pages = '';
1505                                                 foreach ( $cascadingSources as $page )
1506                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1507                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1508                                         }
1509                                 }
1510                         }
1511                 }
1512
1513                 return $errors;
1514         }
1515
1516         /**
1517          * Check action permissions not already checked in checkQuickPermissions
1518          *
1519          * @param $action String the action to check
1520          * @param $user User to check
1521          * @param $errors Array list of current errors
1522          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1523          * @param $short Boolean short circuit on first error
1524          *
1525          * @return Array list of errors
1526          */
1527         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1528                 if ( $action == 'protect' ) {
1529                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1530                                 // If they can't edit, they shouldn't protect.
1531                                 $errors[] = array( 'protect-cantedit' );
1532                         }
1533                 } elseif ( $action == 'create' ) {
1534                         $title_protection = $this->getTitleProtection();
1535                         if( $title_protection ) {
1536                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1537                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1538                                 }
1539                                 if( $title_protection['pt_create_perm'] == '' ||
1540                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1541                                                 $this->mNamespace ) ) {
1542                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1543                                 }
1544                         }
1545                 } elseif ( $action == 'move' ) {
1546                         // Check for immobile pages
1547                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1548                                 // Specific message for this case
1549                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1550                         } elseif ( !$this->isMovable() ) {
1551                                 // Less specific message for rarer cases
1552                                 $errors[] = array( 'immobile-source-page' );
1553                         }
1554                 } elseif ( $action == 'move-target' ) {
1555                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1556                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1557                         } elseif ( !$this->isMovable() ) {
1558                                 $errors[] = array( 'immobile-target-page' );
1559                         }
1560                 }
1561                 return $errors;
1562         }
1563
1564         /**
1565          * Check that the user isn't blocked from editting.
1566          *
1567          * @param $action String the action to check
1568          * @param $user User to check
1569          * @param $errors Array list of current errors
1570          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1571          * @param $short Boolean short circuit on first error
1572          *
1573          * @return Array list of errors
1574          */
1575         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1576                 // Account creation blocks handled at userlogin.
1577                 // Unblocking handled in SpecialUnblock
1578                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1579                         return $errors;
1580                 }
1581
1582                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1583
1584                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1585                         $errors[] = array( 'confirmedittext' );
1586                 }
1587
1588                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1589                         // Don't block the user from editing their own talk page unless they've been
1590                         // explicitly blocked from that too.
1591                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1592                         $block = $user->mBlock;
1593
1594                         // This is from OutputPage::blockedPage
1595                         // Copied at r23888 by werdna
1596
1597                         $id = $user->blockedBy();
1598                         $reason = $user->blockedFor();
1599                         if ( $reason == '' ) {
1600                                 $reason = wfMsg( 'blockednoreason' );
1601                         }
1602                         $ip = $user->getRequest()->getIP();
1603
1604                         if ( is_numeric( $id ) ) {
1605                                 $name = User::whoIs( $id );
1606                         } else {
1607                                 $name = $id;
1608                         }
1609
1610                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1611                         $blockid = $block->getId();
1612                         $blockExpiry = $user->mBlock->mExpiry;
1613                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1614                         if ( $blockExpiry == 'infinity' ) {
1615                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1616                         } else {
1617                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1618                         }
1619
1620                         $intended = strval( $user->mBlock->getTarget() );
1621
1622                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1623                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1624                 }
1625
1626                 return $errors;
1627         }
1628
1629         /**
1630          * Check that the user is allowed to read this page.
1631          *
1632          * @param $action String the action to check
1633          * @param $user User to check
1634          * @param $errors Array list of current errors
1635          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1636          * @param $short Boolean short circuit on first error
1637          *
1638          * @return Array list of errors
1639          */
1640         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1641                 static $useShortcut = null;
1642
1643                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1644                 if ( is_null( $useShortcut ) ) {
1645                         global $wgGroupPermissions, $wgRevokePermissions;
1646                         $useShortcut = true;
1647                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1648                                 # Not a public wiki, so no shortcut
1649                                 $useShortcut = false;
1650                         } elseif ( !empty( $wgRevokePermissions ) ) {
1651                                 /**
1652                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1653                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1654                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1655                                  * reading is allowed.
1656                                  */
1657                                 foreach ( $wgRevokePermissions as $perms ) {
1658                                         if ( !empty( $perms['read'] ) ) {
1659                                                 # We might be removing the read right from the user, so no shortcut
1660                                                 $useShortcut = false;
1661                                                 break;
1662                                         }
1663                                 }
1664                         }
1665                 }
1666
1667                 # Shortcut for public wikis, allows skipping quite a bit of code
1668                 if ( $useShortcut ) {
1669                         return $errors;
1670                 }
1671
1672                 # If the user is allowed to read pages, he is allowed to read all pages
1673                 if ( $user->isAllowed( 'read', $this->mNamespace ) ) {
1674                         return $errors;
1675                 }
1676
1677                 # Always grant access to the login page.
1678                 # Even anons need to be able to log in.
1679                 if ( $this->isSpecial( 'Userlogin' )
1680                         || $this->isSpecial( 'ChangePassword' )
1681                         || $this->isSpecial( 'PasswordReset' )
1682                 ) {
1683                         return $errors;
1684                 }
1685
1686                 # Time to check the whitelist
1687                 global $wgWhitelistRead;
1688
1689                 # Only to these checks is there's something to check against
1690                 if ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
1691                         # Check for explicit whitelisting
1692                         $name = $this->getPrefixedText();
1693                         $dbName = $this->getPrefixedDBKey();
1694
1695                         // Check with and without underscores
1696                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
1697                                 return $errors;
1698                         }
1699
1700                         # Old settings might have the title prefixed with
1701                         # a colon for main-namespace pages
1702                         if ( $this->getNamespace() == NS_MAIN ) {
1703                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1704                                         return $errors;
1705                                 }
1706                         }
1707
1708                         # If it's a special page, ditch the subpage bit and check again
1709                         if ( $this->isSpecialPage() ) {
1710                                 $name = $this->getDBkey();
1711                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1712                                 if ( $name !== false ) {
1713                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1714                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1715                                                 return $errors;
1716                                         }
1717                                 }
1718                         }
1719                 }
1720
1721                 $errors[] = $this->missingPermissionError( $action, $short );
1722                 return $errors;
1723         }
1724
1725         /**
1726          * Get a description array when the user doesn't have the right to perform
1727          * $action (i.e. when User::isAllowed() returns false)
1728          *
1729          * @param $action String the action to check
1730          * @param $short Boolean short circuit on first error
1731          * @return Array list of errors
1732          */
1733         private function missingPermissionError( $action, $short ) {
1734                 // We avoid expensive display logic for quickUserCan's and such
1735                 if ( $short ) {
1736                         return array( 'badaccess-group0' );
1737                 }
1738
1739                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1740                         User::getGroupsWithPermission( $action, $this->mNamespace ) );
1741
1742                 if ( count( $groups ) ) {
1743                         global $wgLang;
1744                         return array(
1745                                 'badaccess-groups',
1746                                 $wgLang->commaList( $groups ),
1747                                 count( $groups )
1748                         );
1749                 } else {
1750                         return array( 'badaccess-group0' );
1751                 }
1752         }
1753
1754         /**
1755          * Can $user perform $action on this page? This is an internal function,
1756          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1757          * checks on wfReadOnly() and blocks)
1758          *
1759          * @param $action String action that permission needs to be checked for
1760          * @param $user User to check
1761          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1762          * @param $short Bool Set this to true to stop after the first permission error.
1763          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1764          */
1765         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1766                 wfProfileIn( __METHOD__ );
1767
1768                 # Read has special handling
1769                 if ( $action == 'read' ) {
1770                         $checks = array(
1771                                 'checkPermissionHooks',
1772                                 'checkReadPermissions',
1773                         );
1774                 } else {
1775                         $checks = array(
1776                                 'checkQuickPermissions',
1777                                 'checkPermissionHooks',
1778                                 'checkSpecialsAndNSPermissions',
1779                                 'checkCSSandJSPermissions',
1780                                 'checkPageRestrictions',
1781                                 'checkCascadingSourcesRestrictions',
1782                                 'checkActionPermissions',
1783                                 'checkUserBlock'
1784                         );
1785                 }
1786
1787                 $errors = array();
1788                 while( count( $checks ) > 0 &&
1789                                 !( $short && count( $errors ) > 0 ) ) {
1790                         $method = array_shift( $checks );
1791                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1792                 }
1793
1794                 wfProfileOut( __METHOD__ );
1795                 return $errors;
1796         }
1797
1798         /**
1799          * Is this title subject to title protection?
1800          * Title protection is the one applied against creation of such title.
1801          *
1802          * @return Mixed An associative array representing any existent title
1803          *   protection, or false if there's none.
1804          */
1805         private function getTitleProtection() {
1806                 // Can't protect pages in special namespaces
1807                 if ( $this->getNamespace() < 0 ) {
1808                         return false;
1809                 }
1810
1811                 // Can't protect pages that exist.
1812                 if ( $this->exists() ) {
1813                         return false;
1814                 }
1815
1816                 if ( !isset( $this->mTitleProtection ) ) {
1817                         $dbr = wfGetDB( DB_SLAVE );
1818                         $res = $dbr->select( 'protected_titles', '*',
1819                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1820                                 __METHOD__ );
1821
1822                         // fetchRow returns false if there are no rows.
1823                         $this->mTitleProtection = $dbr->fetchRow( $res );
1824                 }
1825                 return $this->mTitleProtection;
1826         }
1827
1828         /**
1829          * Update the title protection status
1830          *
1831          * @param $create_perm String Permission required for creation
1832          * @param $reason String Reason for protection
1833          * @param $expiry String Expiry timestamp
1834          * @return boolean true
1835          */
1836         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1837                 global $wgUser, $wgContLang;
1838
1839                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1840                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1841                         // No change
1842                         return true;
1843                 }
1844
1845                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1846
1847                 $dbw = wfGetDB( DB_MASTER );
1848
1849                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1850
1851                 $expiry_description = '';
1852                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1853                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1854                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1855                 } else {
1856                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1857                 }
1858
1859                 # Update protection table
1860                 if ( $create_perm != '' ) {
1861                         $this->mTitleProtection = array(
1862                                         'pt_namespace' => $namespace,
1863                                         'pt_title' => $title,
1864                                         'pt_create_perm' => $create_perm,
1865                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1866                                         'pt_expiry' => $encodedExpiry,
1867                                         'pt_user' => $wgUser->getId(),
1868                                         'pt_reason' => $reason,
1869                                 );
1870                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1871                                 $this->mTitleProtection, __METHOD__     );
1872                 } else {
1873                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1874                                 'pt_title' => $title ), __METHOD__ );
1875                         $this->mTitleProtection = false;
1876                 }
1877
1878                 # Update the protection log
1879                 if ( $dbw->affectedRows() ) {
1880                         $log = new LogPage( 'protect' );
1881
1882                         if ( $create_perm ) {
1883                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1884                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1885                         } else {
1886                                 $log->addEntry( 'unprotect', $this, $reason );
1887                         }
1888                 }
1889
1890                 return true;
1891         }
1892
1893         /**
1894          * Remove any title protection due to page existing
1895          */
1896         public function deleteTitleProtection() {
1897                 $dbw = wfGetDB( DB_MASTER );
1898
1899                 $dbw->delete(
1900                         'protected_titles',
1901                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1902                         __METHOD__
1903                 );
1904                 $this->mTitleProtection = false;
1905         }
1906
1907         /**
1908          * Would anybody with sufficient privileges be able to move this page?
1909          * Some pages just aren't movable.
1910          *
1911          * @return Bool TRUE or FALSE
1912          */
1913         public function isMovable() {
1914                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
1915                         // Interwiki title or immovable namespace. Hooks don't get to override here
1916                         return false;
1917                 }
1918
1919                 $result = true;
1920                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1921                 return $result;
1922         }
1923
1924         /**
1925          * Is this the mainpage?
1926          * @note Title::newFromText seams to be sufficiently optimized by the title
1927          * cache that we don't need to over-optimize by doing direct comparisons and
1928          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1929          * ends up reporting something differently than $title->isMainPage();
1930          *
1931          * @since 1.18
1932          * @return Bool
1933          */
1934         public function isMainPage() {
1935                 return $this->equals( Title::newMainPage() );
1936         }
1937
1938         /**
1939          * Is this a talk page of some sort?
1940          *
1941          * @return Bool
1942          */
1943         public function isTalkPage() {
1944                 return MWNamespace::isTalk( $this->getNamespace() );
1945         }
1946
1947         /**
1948          * Is this a subpage?
1949          *
1950          * @return Bool
1951          */
1952         public function isSubpage() {
1953                 return MWNamespace::hasSubpages( $this->mNamespace )
1954                         ? strpos( $this->getText(), '/' ) !== false
1955                         : false;
1956         }
1957
1958         /**
1959          * Returns true if the title is inside the specified namespace.
1960          *
1961          * Please make use of this instead of comparing to getNamespace()
1962          * This function is much more resistant to changes we may make
1963          * to namespaces than code that makes direct comparisons.
1964          * @param $ns int The namespace
1965          * @return bool
1966          * @since 1.19
1967          */
1968         public function inNamespace( $ns ) {
1969                 return MWNamespace::equals( $this->getNamespace(), $ns );
1970         }
1971
1972         /**
1973          * Returns true if the title is inside one of the specified namespaces.
1974          *
1975          * @param ...$namespaces The namespaces to check for
1976          * @return bool
1977          * @since 1.19
1978          */
1979         public function inNamespaces( /* ... */ ) {
1980                 $namespaces = func_get_args();
1981                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1982                         $namespaces = $namespaces[0];
1983                 }
1984
1985                 foreach ( $namespaces as $ns ) {
1986                         if ( $this->inNamespace( $ns ) ) {
1987                                 return true;
1988                         }
1989                 }
1990
1991                 return false;
1992         }
1993
1994         /**
1995          * Returns true if the title has the same subject namespace as the
1996          * namespace specified.
1997          * For example this method will take NS_USER and return true if namespace
1998          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1999          * as their subject namespace.
2000          *
2001          * This is MUCH simpler than individually testing for equivilance
2002          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
2003          * @since 1.19
2004          */
2005         public function hasSubjectNamespace( $ns ) {
2006                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
2007         }
2008
2009         /**
2010          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2011          *
2012          * @return Bool
2013          */
2014         public function hasSubpages() {
2015                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2016                         # Duh
2017                         return false;
2018                 }
2019
2020                 # We dynamically add a member variable for the purpose of this method
2021                 # alone to cache the result.  There's no point in having it hanging
2022                 # around uninitialized in every Title object; therefore we only add it
2023                 # if needed and don't declare it statically.
2024                 if ( isset( $this->mHasSubpages ) ) {
2025                         return $this->mHasSubpages;
2026                 }
2027
2028                 $subpages = $this->getSubpages( 1 );
2029                 if ( $subpages instanceof TitleArray ) {
2030                         return $this->mHasSubpages = (bool)$subpages->count();
2031                 }
2032                 return $this->mHasSubpages = false;
2033         }
2034
2035         /**
2036          * Get all subpages of this page.
2037          *
2038          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2039          * @return mixed TitleArray, or empty array if this page's namespace
2040          *  doesn't allow subpages
2041          */
2042         public function getSubpages( $limit = -1 ) {
2043                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2044                         return array();
2045                 }
2046
2047                 $dbr = wfGetDB( DB_SLAVE );
2048                 $conds['page_namespace'] = $this->getNamespace();
2049                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2050                 $options = array();
2051                 if ( $limit > -1 ) {
2052                         $options['LIMIT'] = $limit;
2053                 }
2054                 return $this->mSubpages = TitleArray::newFromResult(
2055                         $dbr->select( 'page',
2056                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2057                                 $conds,
2058                                 __METHOD__,
2059                                 $options
2060                         )
2061                 );
2062         }
2063
2064         /**
2065          * Does that page contain wikitext, or it is JS, CSS or whatever?
2066          *
2067          * @return Bool
2068          */
2069         public function isWikitextPage() {
2070                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
2071                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
2072                 return $retval;
2073         }
2074
2075         /**
2076          * Could this page contain custom CSS or JavaScript, based
2077          * on the title?
2078          *
2079          * @return Bool
2080          */
2081         public function isCssOrJsPage() {
2082                 $retval = $this->mNamespace == NS_MEDIAWIKI
2083                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
2084                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
2085                 return $retval;
2086         }
2087
2088         /**
2089          * Is this a .css or .js subpage of a user page?
2090          * @return Bool
2091          */
2092         public function isCssJsSubpage() {
2093                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
2094         }
2095
2096         /**
2097          * Is this a *valid* .css or .js subpage of a user page?
2098          *
2099          * @return Bool
2100          * @deprecated since 1.17
2101          */
2102         public function isValidCssJsSubpage() {
2103                 return $this->isCssJsSubpage();
2104         }
2105
2106         /**
2107          * Trim down a .css or .js subpage title to get the corresponding skin name
2108          *
2109          * @return string containing skin name from .css or .js subpage title
2110          */
2111         public function getSkinFromCssJsSubpage() {
2112                 $subpage = explode( '/', $this->mTextform );
2113                 $subpage = $subpage[ count( $subpage ) - 1 ];
2114                 $lastdot = strrpos( $subpage, '.' );
2115                 if ( $lastdot === false )
2116                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
2117                 return substr( $subpage, 0, $lastdot );
2118         }
2119
2120         /**
2121          * Is this a .css subpage of a user page?
2122          *
2123          * @return Bool
2124          */
2125         public function isCssSubpage() {
2126                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2127         }
2128
2129         /**
2130          * Is this a .js subpage of a user page?
2131          *
2132          * @return Bool
2133          */
2134         public function isJsSubpage() {
2135                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2136         }
2137
2138         /**
2139          * Protect css subpages of user pages: can $wgUser edit
2140          * this page?
2141          *
2142          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2143          * @return Bool
2144          */
2145         public function userCanEditCssSubpage() {
2146                 global $wgUser;
2147                 wfDeprecated( __METHOD__ );
2148                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2149                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2150         }
2151
2152         /**
2153          * Protect js subpages of user pages: can $wgUser edit
2154          * this page?
2155          *
2156          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2157          * @return Bool
2158          */
2159         public function userCanEditJsSubpage() {
2160                 global $wgUser;
2161                 wfDeprecated( __METHOD__ );
2162                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2163                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2164         }
2165
2166         /**
2167          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2168          *
2169          * @return Bool If the page is subject to cascading restrictions.
2170          */
2171         public function isCascadeProtected() {
2172                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2173                 return ( $sources > 0 );
2174         }
2175
2176         /**
2177          * Cascading protection: Get the source of any cascading restrictions on this page.
2178          *
2179          * @param $getPages Bool Whether or not to retrieve the actual pages
2180          *        that the restrictions have come from.
2181          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2182          *     have come, false for none, or true if such restrictions exist, but $getPages
2183          *     was not set.  The restriction array is an array of each type, each of which
2184          *     contains a array of unique groups.
2185          */
2186         public function getCascadeProtectionSources( $getPages = true ) {
2187                 global $wgContLang;
2188                 $pagerestrictions = array();
2189
2190                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2191                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2192                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2193                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2194                 }
2195
2196                 wfProfileIn( __METHOD__ );
2197
2198                 $dbr = wfGetDB( DB_SLAVE );
2199
2200                 if ( $this->getNamespace() == NS_FILE ) {
2201                         $tables = array( 'imagelinks', 'page_restrictions' );
2202                         $where_clauses = array(
2203                                 'il_to' => $this->getDBkey(),
2204                                 'il_from=pr_page',
2205                                 'pr_cascade' => 1
2206                         );
2207                 } else {
2208                         $tables = array( 'templatelinks', 'page_restrictions' );
2209                         $where_clauses = array(
2210                                 'tl_namespace' => $this->getNamespace(),
2211                                 'tl_title' => $this->getDBkey(),
2212                                 'tl_from=pr_page',
2213                                 'pr_cascade' => 1
2214                         );
2215                 }
2216
2217                 if ( $getPages ) {
2218                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2219                                                    'pr_expiry', 'pr_type', 'pr_level' );
2220                         $where_clauses[] = 'page_id=pr_page';
2221                         $tables[] = 'page';
2222                 } else {
2223                         $cols = array( 'pr_expiry' );
2224                 }
2225
2226                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2227
2228                 $sources = $getPages ? array() : false;
2229                 $now = wfTimestampNow();
2230                 $purgeExpired = false;
2231
2232                 foreach ( $res as $row ) {
2233                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2234                         if ( $expiry > $now ) {
2235                                 if ( $getPages ) {
2236                                         $page_id = $row->pr_page;
2237                                         $page_ns = $row->page_namespace;
2238                                         $page_title = $row->page_title;
2239                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2240                                         # Add groups needed for each restriction type if its not already there
2241                                         # Make sure this restriction type still exists
2242
2243                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2244                                                 $pagerestrictions[$row->pr_type] = array();
2245                                         }
2246
2247                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2248                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2249                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2250                                         }
2251                                 } else {
2252                                         $sources = true;
2253                                 }
2254                         } else {
2255                                 // Trigger lazy purge of expired restrictions from the db
2256                                 $purgeExpired = true;
2257                         }
2258                 }
2259                 if ( $purgeExpired ) {
2260                         Title::purgeExpiredRestrictions();
2261                 }
2262
2263                 if ( $getPages ) {
2264                         $this->mCascadeSources = $sources;
2265                         $this->mCascadingRestrictions = $pagerestrictions;
2266                 } else {
2267                         $this->mHasCascadingRestrictions = $sources;
2268                 }
2269
2270                 wfProfileOut( __METHOD__ );
2271                 return array( $sources, $pagerestrictions );
2272         }
2273
2274         /**
2275          * Returns cascading restrictions for the current article
2276          *
2277          * @return Boolean
2278          */
2279         function areRestrictionsCascading() {
2280                 if ( !$this->mRestrictionsLoaded ) {
2281                         $this->loadRestrictions();
2282                 }
2283
2284                 return $this->mCascadeRestriction;
2285         }
2286
2287         /**
2288          * Loads a string into mRestrictions array
2289          *
2290          * @param $res Resource restrictions as an SQL result.
2291          * @param $oldFashionedRestrictions String comma-separated list of page
2292          *        restrictions from page table (pre 1.10)
2293          */
2294         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2295                 $rows = array();
2296
2297                 foreach ( $res as $row ) {
2298                         $rows[] = $row;
2299                 }
2300
2301                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2302         }
2303
2304         /**
2305          * Compiles list of active page restrictions from both page table (pre 1.10)
2306          * and page_restrictions table for this existing page.
2307          * Public for usage by LiquidThreads.
2308          *
2309          * @param $rows array of db result objects
2310          * @param $oldFashionedRestrictions string comma-separated list of page
2311          *        restrictions from page table (pre 1.10)
2312          */
2313         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2314                 global $wgContLang;
2315                 $dbr = wfGetDB( DB_SLAVE );
2316
2317                 $restrictionTypes = $this->getRestrictionTypes();
2318
2319                 foreach ( $restrictionTypes as $type ) {
2320                         $this->mRestrictions[$type] = array();
2321                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2322                 }
2323
2324                 $this->mCascadeRestriction = false;
2325
2326                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2327
2328                 if ( $oldFashionedRestrictions === null ) {
2329                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2330                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2331                 }
2332
2333                 if ( $oldFashionedRestrictions != '' ) {
2334
2335                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2336                                 $temp = explode( '=', trim( $restrict ) );
2337                                 if ( count( $temp ) == 1 ) {
2338                                         // old old format should be treated as edit/move restriction
2339                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2340                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2341                                 } else {
2342                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2343                                 }
2344                         }
2345
2346                         $this->mOldRestrictions = true;
2347
2348                 }
2349
2350                 if ( count( $rows ) ) {
2351                         # Current system - load second to make them override.
2352                         $now = wfTimestampNow();
2353                         $purgeExpired = false;
2354
2355                         # Cycle through all the restrictions.
2356                         foreach ( $rows as $row ) {
2357
2358                                 // Don't take care of restrictions types that aren't allowed
2359                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2360                                         continue;
2361
2362                                 // This code should be refactored, now that it's being used more generally,
2363                                 // But I don't really see any harm in leaving it in Block for now -werdna
2364                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2365
2366                                 // Only apply the restrictions if they haven't expired!
2367                                 if ( !$expiry || $expiry > $now ) {
2368                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2369                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2370
2371                                         $this->mCascadeRestriction |= $row->pr_cascade;
2372                                 } else {
2373                                         // Trigger a lazy purge of expired restrictions
2374                                         $purgeExpired = true;
2375                                 }
2376                         }
2377
2378                         if ( $purgeExpired ) {
2379                                 Title::purgeExpiredRestrictions();
2380                         }
2381                 }
2382
2383                 $this->mRestrictionsLoaded = true;
2384         }
2385
2386         /**
2387          * Load restrictions from the page_restrictions table
2388          *
2389          * @param $oldFashionedRestrictions String comma-separated list of page
2390          *        restrictions from page table (pre 1.10)
2391          */
2392         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2393                 global $wgContLang;
2394                 if ( !$this->mRestrictionsLoaded ) {
2395                         if ( $this->exists() ) {
2396                                 $dbr = wfGetDB( DB_SLAVE );
2397
2398                                 $res = $dbr->select(
2399                                         'page_restrictions',
2400                                         '*',
2401                                         array( 'pr_page' => $this->getArticleId() ),
2402                                         __METHOD__
2403                                 );
2404
2405                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2406                         } else {
2407                                 $title_protection = $this->getTitleProtection();
2408
2409                                 if ( $title_protection ) {
2410                                         $now = wfTimestampNow();
2411                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2412
2413                                         if ( !$expiry || $expiry > $now ) {
2414                                                 // Apply the restrictions
2415                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2416                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2417                                         } else { // Get rid of the old restrictions
2418                                                 Title::purgeExpiredRestrictions();
2419                                                 $this->mTitleProtection = false;
2420                                         }
2421                                 } else {
2422                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2423                                 }
2424                                 $this->mRestrictionsLoaded = true;
2425                         }
2426                 }
2427         }
2428
2429         /**
2430          * Purge expired restrictions from the page_restrictions table
2431          */
2432         static function purgeExpiredRestrictions() {
2433                 $dbw = wfGetDB( DB_MASTER );
2434                 $dbw->delete(
2435                         'page_restrictions',
2436                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2437                         __METHOD__
2438                 );
2439
2440                 $dbw->delete(
2441                         'protected_titles',
2442                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2443                         __METHOD__
2444                 );
2445         }
2446
2447         /**
2448          * Accessor/initialisation for mRestrictions
2449          *
2450          * @param $action String action that permission needs to be checked for
2451          * @return Array of Strings the array of groups allowed to edit this article
2452          */
2453         public function getRestrictions( $action ) {
2454                 if ( !$this->mRestrictionsLoaded ) {
2455                         $this->loadRestrictions();
2456                 }
2457                 return isset( $this->mRestrictions[$action] )
2458                                 ? $this->mRestrictions[$action]
2459                                 : array();
2460         }
2461
2462         /**
2463          * Get the expiry time for the restriction against a given action
2464          *
2465          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2466          *      or not protected at all, or false if the action is not recognised.
2467          */
2468         public function getRestrictionExpiry( $action ) {
2469                 if ( !$this->mRestrictionsLoaded ) {
2470                         $this->loadRestrictions();
2471                 }
2472                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2473         }
2474
2475         /**
2476          * Is there a version of this page in the deletion archive?
2477          *
2478          * @return Int the number of archived revisions
2479          */
2480         public function isDeleted() {
2481                 if ( $this->getNamespace() < 0 ) {
2482                         $n = 0;
2483                 } else {
2484                         $dbr = wfGetDB( DB_SLAVE );
2485
2486                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2487                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2488                                 __METHOD__
2489                         );
2490                         if ( $this->getNamespace() == NS_FILE ) {
2491                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2492                                         array( 'fa_name' => $this->getDBkey() ),
2493                                         __METHOD__
2494                                 );
2495                         }
2496                 }
2497                 return (int)$n;
2498         }
2499
2500         /**
2501          * Is there a version of this page in the deletion archive?
2502          *
2503          * @return Boolean
2504          */
2505         public function isDeletedQuick() {
2506                 if ( $this->getNamespace() < 0 ) {
2507                         return false;
2508                 }
2509                 $dbr = wfGetDB( DB_SLAVE );
2510                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2511                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2512                         __METHOD__
2513                 );
2514                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2515                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2516                                 array( 'fa_name' => $this->getDBkey() ),
2517                                 __METHOD__
2518                         );
2519                 }
2520                 return $deleted;
2521         }
2522
2523         /**
2524          * Get the number of views of this page
2525          *
2526          * @return int The view count for the page
2527          */
2528         public function getCount() {
2529                 if ( $this->mCounter == -1 ) {
2530                         if ( $this->exists() ) {
2531                                 $dbr = wfGetDB( DB_SLAVE );
2532                                 $this->mCounter = $dbr->selectField( 'page',
2533                                         'page_counter',
2534                                         array( 'page_id' => $this->getArticleID() ),
2535                                         __METHOD__
2536                                 );
2537                         } else {
2538                                 $this->mCounter = 0;
2539                         }
2540                 }
2541
2542                 return $this->mCounter;
2543         }
2544
2545         /**
2546          * Get the article ID for this Title from the link cache,
2547          * adding it if necessary
2548          *
2549          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2550          *  for update
2551          * @return Int the ID
2552          */
2553         public function getArticleID( $flags = 0 ) {
2554                 if ( $this->getNamespace() < 0 ) {
2555                         return $this->mArticleID = 0;
2556                 }
2557                 $linkCache = LinkCache::singleton();
2558                 if ( $flags & self::GAID_FOR_UPDATE ) {
2559                         $oldUpdate = $linkCache->forUpdate( true );
2560                         $linkCache->clearLink( $this );
2561                         $this->mArticleID = $linkCache->addLinkObj( $this );
2562                         $linkCache->forUpdate( $oldUpdate );
2563                 } else {
2564                         if ( -1 == $this->mArticleID ) {
2565                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2566                         }
2567                 }
2568                 return $this->mArticleID;
2569         }
2570
2571         /**
2572          * Is this an article that is a redirect page?
2573          * Uses link cache, adding it if necessary
2574          *
2575          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2576          * @return Bool
2577          */
2578         public function isRedirect( $flags = 0 ) {
2579                 if ( !is_null( $this->mRedirect ) ) {
2580                         return $this->mRedirect;
2581                 }
2582                 # Calling getArticleID() loads the field from cache as needed
2583                 if ( !$this->getArticleID( $flags ) ) {
2584                         return $this->mRedirect = false;
2585                 }
2586                 $linkCache = LinkCache::singleton();
2587                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2588
2589                 return $this->mRedirect;
2590         }
2591
2592         /**
2593          * What is the length of this page?
2594          * Uses link cache, adding it if necessary
2595          *
2596          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2597          * @return Int
2598          */
2599         public function getLength( $flags = 0 ) {
2600                 if ( $this->mLength != -1 ) {
2601                         return $this->mLength;
2602                 }
2603                 # Calling getArticleID() loads the field from cache as needed
2604                 if ( !$this->getArticleID( $flags ) ) {
2605                         return $this->mLength = 0;
2606                 }
2607                 $linkCache = LinkCache::singleton();
2608                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2609
2610                 return $this->mLength;
2611         }
2612
2613         /**
2614          * What is the page_latest field for this page?
2615          *
2616          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2617          * @return Int or 0 if the page doesn't exist
2618          */
2619         public function getLatestRevID( $flags = 0 ) {
2620                 if ( $this->mLatestID !== false ) {
2621                         return intval( $this->mLatestID );
2622                 }
2623                 # Calling getArticleID() loads the field from cache as needed
2624                 if ( !$this->getArticleID( $flags ) ) {
2625                         return $this->mLatestID = 0;
2626                 }
2627                 $linkCache = LinkCache::singleton();
2628                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2629
2630                 return $this->mLatestID;
2631         }
2632
2633         /**
2634          * This clears some fields in this object, and clears any associated
2635          * keys in the "bad links" section of the link cache.
2636          *
2637          * - This is called from Article::doEdit() and Article::insertOn() to allow
2638          * loading of the new page_id. It's also called from
2639          * Article::doDeleteArticle()
2640          *
2641          * @param $newid Int the new Article ID
2642          */
2643         public function resetArticleID( $newid ) {
2644                 $linkCache = LinkCache::singleton();
2645                 $linkCache->clearLink( $this );
2646
2647                 if ( $newid === false ) {
2648                         $this->mArticleID = -1;
2649                 } else {
2650                         $this->mArticleID = intval( $newid );
2651                 }
2652                 $this->mRestrictionsLoaded = false;
2653                 $this->mRestrictions = array();
2654                 $this->mRedirect = null;
2655                 $this->mLength = -1;
2656                 $this->mLatestID = false;
2657                 $this->mCounter = -1;
2658         }
2659
2660         /**
2661          * Updates page_touched for this page; called from LinksUpdate.php
2662          *
2663          * @return Bool true if the update succeded
2664          */
2665         public function invalidateCache() {
2666                 if ( wfReadOnly() ) {
2667                         return false;
2668                 }
2669                 $dbw = wfGetDB( DB_MASTER );
2670                 $success = $dbw->update(
2671                         'page',
2672                         array( 'page_touched' => $dbw->timestamp() ),
2673                         $this->pageCond(),
2674                         __METHOD__
2675                 );
2676                 HTMLFileCache::clearFileCache( $this );
2677                 return $success;
2678         }
2679
2680         /**
2681          * Prefix some arbitrary text with the namespace or interwiki prefix
2682          * of this object
2683          *
2684          * @param $name String the text
2685          * @return String the prefixed text
2686          * @private
2687          */
2688         private function prefix( $name ) {
2689                 $p = '';
2690                 if ( $this->mInterwiki != '' ) {
2691                         $p = $this->mInterwiki . ':';
2692                 }
2693
2694                 if ( 0 != $this->mNamespace ) {
2695                         $p .= $this->getNsText() . ':';
2696                 }
2697                 return $p . $name;
2698         }
2699
2700         /**
2701          * Returns a simple regex that will match on characters and sequences invalid in titles.
2702          * Note that this doesn't pick up many things that could be wrong with titles, but that
2703          * replacing this regex with something valid will make many titles valid.
2704          *
2705          * @return String regex string
2706          */
2707         static function getTitleInvalidRegex() {
2708                 static $rxTc = false;
2709                 if ( !$rxTc ) {
2710                         # Matching titles will be held as illegal.
2711                         $rxTc = '/' .
2712                                 # Any character not allowed is forbidden...
2713                                 '[^' . Title::legalChars() . ']' .
2714                                 # URL percent encoding sequences interfere with the ability
2715                                 # to round-trip titles -- you can't link to them consistently.
2716                                 '|%[0-9A-Fa-f]{2}' .
2717                                 # XML/HTML character references produce similar issues.
2718                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2719                                 '|&#[0-9]+;' .
2720                                 '|&#x[0-9A-Fa-f]+;' .
2721                                 '/S';
2722                 }
2723
2724                 return $rxTc;
2725         }
2726
2727         /**
2728          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2729          *
2730          * @param $text String containing title to capitalize
2731          * @param $ns int namespace index, defaults to NS_MAIN
2732          * @return String containing capitalized title
2733          */
2734         public static function capitalize( $text, $ns = NS_MAIN ) {
2735                 global $wgContLang;
2736
2737                 if ( MWNamespace::isCapitalized( $ns ) ) {
2738                         return $wgContLang->ucfirst( $text );
2739                 } else {
2740                         return $text;
2741                 }
2742         }
2743
2744         /**
2745          * Secure and split - main initialisation function for this object
2746          *
2747          * Assumes that mDbkeyform has been set, and is urldecoded
2748          * and uses underscores, but not otherwise munged.  This function
2749          * removes illegal characters, splits off the interwiki and
2750          * namespace prefixes, sets the other forms, and canonicalizes
2751          * everything.
2752          *
2753          * @return Bool true on success
2754          */
2755         private function secureAndSplit() {
2756                 global $wgContLang, $wgLocalInterwiki;
2757
2758                 # Initialisation
2759                 $this->mInterwiki = $this->mFragment = '';
2760                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2761
2762                 $dbkey = $this->mDbkeyform;
2763
2764                 # Strip Unicode bidi override characters.
2765                 # Sometimes they slip into cut-n-pasted page titles, where the
2766                 # override chars get included in list displays.
2767                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2768
2769                 # Clean up whitespace
2770                 # Note: use of the /u option on preg_replace here will cause
2771                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2772                 # conveniently disabling them.
2773                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2774                 $dbkey = trim( $dbkey, '_' );
2775
2776                 if ( $dbkey == '' ) {
2777                         return false;
2778                 }
2779
2780                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2781                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2782                         return false;
2783                 }
2784
2785                 $this->mDbkeyform = $dbkey;
2786
2787                 # Initial colon indicates main namespace rather than specified default
2788                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2789                 if ( ':' == $dbkey[0] ) {
2790                         $this->mNamespace = NS_MAIN;
2791                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2792                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2793                 }
2794
2795                 # Namespace or interwiki prefix
2796                 $firstPass = true;
2797                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2798                 do {
2799                         $m = array();
2800                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2801                                 $p = $m[1];
2802                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2803                                         # Ordinary namespace
2804                                         $dbkey = $m[2];
2805                                         $this->mNamespace = $ns;
2806                                         # For Talk:X pages, check if X has a "namespace" prefix
2807                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2808                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2809                                                         # Disallow Talk:File:x type titles...
2810                                                         return false;
2811                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2812                                                         # Disallow Talk:Interwiki:x type titles...
2813                                                         return false;
2814                                                 }
2815                                         }
2816                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2817                                         if ( !$firstPass ) {
2818                                                 # Can't make a local interwiki link to an interwiki link.
2819                                                 # That's just crazy!
2820                                                 return false;
2821                                         }
2822
2823                                         # Interwiki link
2824                                         $dbkey = $m[2];
2825                                         $this->mInterwiki = $wgContLang->lc( $p );
2826
2827                                         # Redundant interwiki prefix to the local wiki
2828                                         if ( $wgLocalInterwiki !== false
2829                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2830                                         {
2831                                                 if ( $dbkey == '' ) {
2832                                                         # Can't have an empty self-link
2833                                                         return false;
2834                                                 }
2835                                                 $this->mInterwiki = '';
2836                                                 $firstPass = false;
2837                                                 # Do another namespace split...
2838                                                 continue;
2839                                         }
2840
2841                                         # If there's an initial colon after the interwiki, that also
2842                                         # resets the default namespace
2843                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2844                                                 $this->mNamespace = NS_MAIN;
2845                                                 $dbkey = substr( $dbkey, 1 );
2846                                         }
2847                                 }
2848                                 # If there's no recognized interwiki or namespace,
2849                                 # then let the colon expression be part of the title.
2850                         }
2851                         break;
2852                 } while ( true );
2853
2854                 # We already know that some pages won't be in the database!
2855                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2856                         $this->mArticleID = 0;
2857                 }
2858                 $fragment = strstr( $dbkey, '#' );
2859                 if ( false !== $fragment ) {
2860                         $this->setFragment( $fragment );
2861                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2862                         # remove whitespace again: prevents "Foo_bar_#"
2863                         # becoming "Foo_bar_"
2864                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2865                 }
2866
2867                 # Reject illegal characters.
2868                 $rxTc = self::getTitleInvalidRegex();
2869                 if ( preg_match( $rxTc, $dbkey ) ) {
2870                         return false;
2871                 }
2872
2873                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2874                 # reachable due to the way web browsers deal with 'relative' URLs.
2875                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2876                 if ( strpos( $dbkey, '.' ) !== false &&
2877                          ( $dbkey === '.' || $dbkey === '..' ||
2878                            strpos( $dbkey, './' ) === 0  ||
2879                            strpos( $dbkey, '../' ) === 0 ||
2880                            strpos( $dbkey, '/./' ) !== false ||
2881                            strpos( $dbkey, '/../' ) !== false  ||
2882                            substr( $dbkey, -2 ) == '/.' ||
2883                            substr( $dbkey, -3 ) == '/..' ) )
2884                 {
2885                         return false;
2886                 }
2887
2888                 # Magic tilde sequences? Nu-uh!
2889                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2890                         return false;
2891                 }
2892
2893                 # Limit the size of titles to 255 bytes. This is typically the size of the
2894                 # underlying database field. We make an exception for special pages, which
2895                 # don't need to be stored in the database, and may edge over 255 bytes due
2896                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2897                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2898                   strlen( $dbkey ) > 512 )
2899                 {
2900                         return false;
2901                 }
2902
2903                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2904                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2905                 # other site might be case-sensitive.
2906                 $this->mUserCaseDBKey = $dbkey;
2907                 if ( $this->mInterwiki == '' ) {
2908                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2909                 }
2910
2911                 # Can't make a link to a namespace alone... "empty" local links can only be
2912                 # self-links with a fragment identifier.
2913                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2914                         return false;
2915                 }
2916
2917                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2918                 // IP names are not allowed for accounts, and can only be referring to
2919                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2920                 // there are numerous ways to present the same IP. Having sp:contribs scan
2921                 // them all is silly and having some show the edits and others not is
2922                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2923                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2924                         ? IP::sanitizeIP( $dbkey )
2925                         : $dbkey;
2926
2927                 // Any remaining initial :s are illegal.
2928                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
2929                         return false;
2930                 }
2931
2932                 # Fill fields
2933                 $this->mDbkeyform = $dbkey;
2934                 $this->mUrlform = wfUrlencode( $dbkey );
2935
2936                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2937
2938                 return true;
2939         }
2940
2941         /**
2942          * Set the fragment for this title. Removes the first character from the
2943          * specified fragment before setting, so it assumes you're passing it with
2944          * an initial "#".
2945          *
2946          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2947          * Still in active use privately.
2948          *
2949          * @param $fragment String text
2950          */
2951         public function setFragment( $fragment ) {
2952                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2953         }
2954
2955         /**
2956          * Get a Title object associated with the talk page of this article
2957          *
2958          * @return Title the object for the talk page
2959          */
2960         public function getTalkPage() {
2961                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2962         }
2963
2964         /**
2965          * Get a title object associated with the subject page of this
2966          * talk page
2967          *
2968          * @return Title the object for the subject page
2969          */
2970         public function getSubjectPage() {
2971                 // Is this the same title?
2972                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2973                 if ( $this->getNamespace() == $subjectNS ) {
2974                         return $this;
2975                 }
2976                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2977         }
2978
2979         /**
2980          * Get an array of Title objects linking to this Title
2981          * Also stores the IDs in the link cache.
2982          *
2983          * WARNING: do not use this function on arbitrary user-supplied titles!
2984          * On heavily-used templates it will max out the memory.
2985          *
2986          * @param $options Array: may be FOR UPDATE
2987          * @param $table String: table name
2988          * @param $prefix String: fields prefix
2989          * @return Array of Title objects linking here
2990          */
2991         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2992                 $linkCache = LinkCache::singleton();
2993
2994                 if ( count( $options ) > 0 ) {
2995                         $db = wfGetDB( DB_MASTER );
2996                 } else {
2997                         $db = wfGetDB( DB_SLAVE );
2998                 }
2999
3000                 $res = $db->select(
3001                         array( 'page', $table ),
3002                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3003                         array(
3004                                 "{$prefix}_from=page_id",
3005                                 "{$prefix}_namespace" => $this->getNamespace(),
3006                                 "{$prefix}_title"     => $this->getDBkey() ),
3007                         __METHOD__,
3008                         $options
3009                 );
3010
3011                 $retVal = array();
3012                 if ( $db->numRows( $res ) ) {
3013                         foreach ( $res as $row ) {
3014                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3015                                 if ( $titleObj ) {
3016                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3017                                         $retVal[] = $titleObj;
3018                                 }
3019                         }
3020                 }
3021                 return $retVal;
3022         }
3023
3024         /**
3025          * Get an array of Title objects using this Title as a template
3026          * Also stores the IDs in the link cache.
3027          *
3028          * WARNING: do not use this function on arbitrary user-supplied titles!
3029          * On heavily-used templates it will max out the memory.
3030          *
3031          * @param $options Array: may be FOR UPDATE
3032          * @return Array of Title the Title objects linking here
3033          */
3034         public function getTemplateLinksTo( $options = array() ) {
3035                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3036         }
3037
3038         /**
3039          * Get an array of Title objects referring to non-existent articles linked from this page
3040          *
3041          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3042          * @return Array of Title the Title objects
3043          */
3044         public function getBrokenLinksFrom() {
3045                 if ( $this->getArticleId() == 0 ) {
3046                         # All links from article ID 0 are false positives
3047                         return array();
3048                 }
3049
3050                 $dbr = wfGetDB( DB_SLAVE );
3051                 $res = $dbr->select(
3052                         array( 'page', 'pagelinks' ),
3053                         array( 'pl_namespace', 'pl_title' ),
3054                         array(
3055                                 'pl_from' => $this->getArticleId(),
3056                                 'page_namespace IS NULL'
3057                         ),
3058                         __METHOD__, array(),
3059                         array(
3060                                 'page' => array(
3061                                         'LEFT JOIN',
3062                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3063                                 )
3064                         )
3065                 );
3066
3067                 $retVal = array();
3068                 foreach ( $res as $row ) {
3069                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3070                 }
3071                 return $retVal;
3072         }
3073
3074
3075         /**
3076          * Get a list of URLs to purge from the Squid cache when this
3077          * page changes
3078          *
3079          * @return Array of String the URLs
3080          */
3081         public function getSquidURLs() {
3082                 global $wgContLang;
3083
3084                 $urls = array(
3085                         $this->getInternalURL(),
3086                         $this->getInternalURL( 'action=history' )
3087                 );
3088
3089                 // purge variant urls as well
3090                 if ( $wgContLang->hasVariants() ) {
3091                         $variants = $wgContLang->getVariants();
3092                         foreach ( $variants as $vCode ) {
3093                                 $urls[] = $this->getInternalURL( '', $vCode );
3094                         }
3095                 }
3096
3097                 return $urls;
3098         }
3099
3100         /**
3101          * Purge all applicable Squid URLs
3102          */
3103         public function purgeSquid() {
3104                 global $wgUseSquid;
3105                 if ( $wgUseSquid ) {
3106                         $urls = $this->getSquidURLs();
3107                         $u = new SquidUpdate( $urls );
3108                         $u->doUpdate();
3109                 }
3110         }
3111
3112         /**
3113          * Move this page without authentication
3114          *
3115          * @param $nt Title the new page Title
3116          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3117          */
3118         public function moveNoAuth( &$nt ) {
3119                 return $this->moveTo( $nt, false );
3120         }
3121
3122         /**
3123          * Check whether a given move operation would be valid.
3124          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3125          *
3126          * @param $nt Title the new title
3127          * @param $auth Bool indicates whether $wgUser's permissions
3128          *  should be checked
3129          * @param $reason String is the log summary of the move, used for spam checking
3130          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3131          */
3132         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3133                 global $wgUser;
3134
3135                 $errors = array();
3136                 if ( !$nt ) {
3137                         // Normally we'd add this to $errors, but we'll get
3138                         // lots of syntax errors if $nt is not an object
3139                         return array( array( 'badtitletext' ) );
3140                 }
3141                 if ( $this->equals( $nt ) ) {
3142                         $errors[] = array( 'selfmove' );
3143                 }
3144                 if ( !$this->isMovable() ) {
3145                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3146                 }
3147                 if ( $nt->getInterwiki() != '' ) {
3148                         $errors[] = array( 'immobile-target-namespace-iw' );
3149                 }
3150                 if ( !$nt->isMovable() ) {
3151                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3152                 }
3153
3154                 $oldid = $this->getArticleID();
3155                 $newid = $nt->getArticleID();
3156
3157                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3158                         $errors[] = array( 'articleexists' );
3159                 }
3160                 if ( ( $this->getDBkey() == '' ) ||
3161                          ( !$oldid ) ||
3162                          ( $nt->getDBkey() == '' ) ) {
3163                         $errors[] = array( 'badarticleerror' );
3164                 }
3165
3166                 // Image-specific checks
3167                 if ( $this->getNamespace() == NS_FILE ) {
3168                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3169                 }
3170
3171                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3172                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3173                 }
3174
3175                 if ( $auth ) {
3176                         $errors = wfMergeErrorArrays( $errors,
3177                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3178                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3179                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3180                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3181                 }
3182
3183                 $match = EditPage::matchSummarySpamRegex( $reason );
3184                 if ( $match !== false ) {
3185                         // This is kind of lame, won't display nice
3186                         $errors[] = array( 'spamprotectiontext' );
3187                 }
3188
3189                 $err = null;
3190                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3191                         $errors[] = array( 'hookaborted', $err );
3192                 }
3193
3194                 # The move is allowed only if (1) the target doesn't exist, or
3195                 # (2) the target is a redirect to the source, and has no history
3196                 # (so we can undo bad moves right after they're done).
3197
3198                 if ( 0 != $newid ) { # Target exists; check for validity
3199                         if ( !$this->isValidMoveTarget( $nt ) ) {
3200                                 $errors[] = array( 'articleexists' );
3201                         }
3202                 } else {
3203                         $tp = $nt->getTitleProtection();
3204                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3205                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3206                                 $errors[] = array( 'cantmove-titleprotected' );
3207                         }
3208                 }
3209                 if ( empty( $errors ) ) {
3210                         return true;
3211                 }
3212                 return $errors;
3213         }
3214
3215         /**
3216          * Check if the requested move target is a valid file move target
3217          * @param Title $nt Target title
3218          * @return array List of errors
3219          */
3220         protected function validateFileMoveOperation( $nt ) {
3221                 global $wgUser;
3222
3223                 $errors = array();
3224
3225                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3226
3227                 $file = wfLocalFile( $this );
3228                 if ( $file->exists() ) {
3229                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3230                                 $errors[] = array( 'imageinvalidfilename' );
3231                         }
3232                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3233                                 $errors[] = array( 'imagetypemismatch' );
3234                         }
3235                 }
3236
3237                 if ( $nt->getNamespace() != NS_FILE ) {
3238                         $errors[] = array( 'imagenocrossnamespace' );
3239                         // From here we want to do checks on a file object, so if we can't
3240                         // create one, we must return.
3241                         return $errors;
3242                 }
3243
3244                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3245
3246                 $destFile = wfLocalFile( $nt );
3247                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3248                         $errors[] = array( 'file-exists-sharedrepo' );
3249                 }
3250
3251                 return $errors;
3252         }
3253
3254         /**
3255          * Move a title to a new location
3256          *
3257          * @param $nt Title the new title
3258          * @param $auth Bool indicates whether $wgUser's permissions
3259          *  should be checked
3260          * @param $reason String the reason for the move
3261          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3262          *  Ignored if the user doesn't have the suppressredirect right.
3263          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3264          */
3265         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3266                 global $wgUser;
3267                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3268                 if ( is_array( $err ) ) {
3269                         // Auto-block user's IP if the account was "hard" blocked
3270                         $wgUser->spreadAnyEditBlock();
3271                         return $err;
3272                 }
3273
3274                 // If it is a file, move it first.
3275                 // It is done before all other moving stuff is done because it's hard to revert.
3276                 $dbw = wfGetDB( DB_MASTER );
3277                 if ( $this->getNamespace() == NS_FILE ) {
3278                         $file = wfLocalFile( $this );
3279                         if ( $file->exists() ) {
3280                                 $status = $file->move( $nt );
3281                                 if ( !$status->isOk() ) {
3282                                         return $status->getErrorsArray();
3283                                 }
3284                         }
3285                 }
3286                 // Clear RepoGroup process cache
3287                 RepoGroup::singleton()->clearCache( $this );
3288                 RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3289
3290                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3291                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3292                 $protected = $this->isProtected();
3293                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3294
3295                 // Do the actual move
3296                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3297                 if ( is_array( $err ) ) {
3298                         # @todo FIXME: What about the File we have already moved?
3299                         $dbw->rollback();
3300                         return $err;
3301                 }
3302
3303                 $redirid = $this->getArticleID();
3304
3305                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3306                 // cl_timestamp, which may disturb time-based lists on some sites.
3307                 $prefixes = $dbw->select(
3308                         'categorylinks',
3309                         array( 'cl_sortkey_prefix', 'cl_to' ),
3310                         array( 'cl_from' => $pageid ),
3311                         __METHOD__
3312                 );
3313                 foreach ( $prefixes as $prefixRow ) {
3314                         $prefix = $prefixRow->cl_sortkey_prefix;
3315                         $catTo = $prefixRow->cl_to;
3316                         $dbw->update( 'categorylinks',
3317                                 array(
3318                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3319                                                 $nt->getCategorySortkey( $prefix ) ),
3320                                         'cl_timestamp=cl_timestamp' ),
3321                                 array(
3322                                         'cl_from' => $pageid,
3323                                         'cl_to' => $catTo ),
3324                                 __METHOD__
3325                         );
3326                 }
3327
3328                 if ( $protected ) {
3329                         # Protect the redirect title as the title used to be...
3330                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3331                                 array(
3332                                         'pr_page'    => $redirid,
3333                                         'pr_type'    => 'pr_type',
3334                                         'pr_level'   => 'pr_level',
3335                                         'pr_cascade' => 'pr_cascade',
3336                                         'pr_user'    => 'pr_user',
3337                                         'pr_expiry'  => 'pr_expiry'
3338                                 ),
3339                                 array( 'pr_page' => $pageid ),
3340                                 __METHOD__,
3341                                 array( 'IGNORE' )
3342                         );
3343                         # Update the protection log
3344                         $log = new LogPage( 'protect' );
3345                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3346                         if ( $reason ) {
3347                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3348                         }
3349                         // @todo FIXME: $params?
3350                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3351                 }
3352
3353                 # Update watchlists
3354                 $oldnamespace = $this->getNamespace() & ~1;
3355                 $newnamespace = $nt->getNamespace() & ~1;
3356                 $oldtitle = $this->getDBkey();
3357                 $newtitle = $nt->getDBkey();
3358
3359                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3360                         WatchedItem::duplicateEntries( $this, $nt );
3361                 }
3362
3363                 # Update search engine
3364                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3365                 $u->doUpdate();
3366                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3367                 $u->doUpdate();
3368
3369                 $dbw->commit();
3370
3371                 # Update site_stats
3372                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3373                         # No longer a content page
3374                         # Not viewed, edited, removing
3375                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3376                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3377                         # Now a content page
3378                         # Not viewed, edited, adding
3379                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3380                 } elseif ( $pageCountChange ) {
3381                         # Redirect added
3382                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3383                 } else {
3384                         # Nothing special
3385                         $u = false;
3386                 }
3387                 if ( $u ) {
3388                         $u->doUpdate();
3389                 }
3390
3391                 # Update message cache for interface messages
3392                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3393                         # @bug 17860: old article can be deleted, if this the case,
3394                         # delete it from message cache
3395                         if ( $this->getArticleID() === 0 ) {
3396                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3397                         } else {
3398                                 $rev = Revision::newFromTitle( $this );
3399                                 MessageCache::singleton()->replace( $this->getDBkey(), $rev->getText() );
3400                         }
3401                 }
3402                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3403                         $rev = Revision::newFromTitle( $nt );
3404                         MessageCache::singleton()->replace( $nt->getDBkey(), $rev->getText() );
3405                 }
3406
3407                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3408                 return true;
3409         }
3410
3411         /**
3412          * Move page to a title which is either a redirect to the
3413          * source page or nonexistent
3414          *
3415          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3416          * @param $reason String The reason for the move
3417          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3418          *   if the user doesn't have the suppressredirect right
3419          */
3420         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3421                 global $wgUser, $wgContLang;
3422
3423                 if ( $nt->exists() ) {
3424                         $moveOverRedirect = true;
3425                         $logType = 'move_redir';
3426                 } else {
3427                         $moveOverRedirect = false;
3428                         $logType = 'move';
3429                 }
3430
3431                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3432
3433                 $logEntry = new ManualLogEntry( 'move', $logType );
3434                 $logEntry->setPerformer( $wgUser );
3435                 $logEntry->setTarget( $this );
3436                 $logEntry->setComment( $reason );
3437                 $logEntry->setParameters( array(
3438                         '4::target' => $nt->getPrefixedText(),
3439                         '5::noredir' => $redirectSuppressed ? '1': '0',
3440                 ) );
3441
3442                 $formatter = LogFormatter::newFromEntry( $logEntry );
3443                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3444                 $comment = $formatter->getPlainActionText();
3445                 if ( $reason ) {
3446                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3447                 }
3448                 # Truncate for whole multibyte characters.
3449                 $comment = $wgContLang->truncate( $comment, 255 );
3450
3451                 $oldid = $this->getArticleID();
3452                 $latest = $this->getLatestRevID();
3453
3454                 $dbw = wfGetDB( DB_MASTER );
3455
3456                 if ( $moveOverRedirect ) {
3457                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3458
3459                         $newid = $nt->getArticleID();
3460                         $newns = $nt->getNamespace();
3461                         $newdbk = $nt->getDBkey();
3462
3463                         # Delete the old redirect. We don't save it to history since
3464                         # by definition if we've got here it's rather uninteresting.
3465                         # We have to remove it so that the next step doesn't trigger
3466                         # a conflict on the unique namespace+title index...
3467                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3468                         if ( !$dbw->cascadingDeletes() ) {
3469                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3470
3471                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3472                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3473                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3474                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3475                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3476                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3477                                 $dbw->delete( 'iwlinks', array( 'iwl_from' => $newid ), __METHOD__ );
3478                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3479                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3480                         }
3481                         // If the target page was recently created, it may have an entry in recentchanges still
3482                         $dbw->delete( 'recentchanges',
3483                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3484                                 __METHOD__
3485                         );
3486                 }
3487
3488                 # Save a null revision in the page's history notifying of the move
3489                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3490                 if ( !is_object( $nullRevision ) ) {
3491                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3492                 }
3493                 $nullRevId = $nullRevision->insertOn( $dbw );
3494
3495                 $now = wfTimestampNow();
3496                 # Change the name of the target page:
3497                 $dbw->update( 'page',
3498                         /* SET */ array(
3499                                 'page_touched'   => $dbw->timestamp( $now ),
3500                                 'page_namespace' => $nt->getNamespace(),
3501                                 'page_title'     => $nt->getDBkey(),
3502                                 'page_latest'    => $nullRevId,
3503                         ),
3504                         /* WHERE */ array( 'page_id' => $oldid ),
3505                         __METHOD__
3506                 );
3507                 $nt->resetArticleID( $oldid );
3508
3509                 $article = WikiPage::factory( $nt );
3510                 wfRunHooks( 'NewRevisionFromEditComplete',
3511                         array( $article, $nullRevision, $latest, $wgUser ) );
3512                 $article->setCachedLastEditTime( $now );
3513
3514                 # Recreate the redirect, this time in the other direction.
3515                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3516                         $mwRedir = MagicWord::get( 'redirect' );
3517                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3518                         $redirectArticle = WikiPage::factory( $this );
3519                         $newid = $redirectArticle->insertOn( $dbw );
3520                         if ( $newid ) { // sanity
3521                                 $redirectRevision = new Revision( array(
3522                                         'page'    => $newid,
3523                                         'comment' => $comment,
3524                                         'text'    => $redirectText ) );
3525                                 $redirectRevision->insertOn( $dbw );
3526                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3527
3528                                 wfRunHooks( 'NewRevisionFromEditComplete',
3529                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3530
3531                                 # Now, we record the link from the redirect to the new title.
3532                                 # It should have no other outgoing links...
3533                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3534                                 $dbw->insert( 'pagelinks',
3535                                         array(
3536                                                 'pl_from'      => $newid,
3537                                                 'pl_namespace' => $nt->getNamespace(),
3538                                                 'pl_title'     => $nt->getDBkey() ),
3539                                         __METHOD__ );
3540                         }
3541                 } else {
3542                         $this->resetArticleID( 0 );
3543                 }
3544
3545                 # Log the move
3546                 $logid = $logEntry->insert();
3547                 $logEntry->publish( $logid );
3548
3549                 # Purge caches for old and new titles
3550                 if ( $moveOverRedirect ) {
3551                         # A simple purge is enough when moving over a redirect
3552                         $nt->purgeSquid();
3553                 } else {
3554                         # Purge caches as per article creation, including any pages that link to this title
3555                         Article::onArticleCreate( $nt );
3556                 }
3557                 $this->purgeSquid();
3558         }
3559
3560         /**
3561          * Move this page's subpages to be subpages of $nt
3562          *
3563          * @param $nt Title Move target
3564          * @param $auth bool Whether $wgUser's permissions should be checked
3565          * @param $reason string The reason for the move
3566          * @param $createRedirect bool Whether to create redirects from the old subpages to
3567          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3568          * @return mixed array with old page titles as keys, and strings (new page titles) or
3569          *     arrays (errors) as values, or an error array with numeric indices if no pages
3570          *     were moved
3571          */
3572         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3573                 global $wgMaximumMovedPages;
3574                 // Check permissions
3575                 if ( !$this->userCan( 'move-subpages' ) ) {
3576                         return array( 'cant-move-subpages' );
3577                 }
3578                 // Do the source and target namespaces support subpages?
3579                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3580                         return array( 'namespace-nosubpages',
3581                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3582                 }
3583                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3584                         return array( 'namespace-nosubpages',
3585                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3586                 }
3587
3588                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3589                 $retval = array();
3590                 $count = 0;
3591                 foreach ( $subpages as $oldSubpage ) {
3592                         $count++;
3593                         if ( $count > $wgMaximumMovedPages ) {
3594                                 $retval[$oldSubpage->getPrefixedTitle()] =
3595                                                 array( 'movepage-max-pages',
3596                                                         $wgMaximumMovedPages );
3597                                 break;
3598                         }
3599
3600                         // We don't know whether this function was called before
3601                         // or after moving the root page, so check both
3602                         // $this and $nt
3603                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3604                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3605                         {
3606                                 // When moving a page to a subpage of itself,
3607                                 // don't move it twice
3608                                 continue;
3609                         }
3610                         $newPageName = preg_replace(
3611                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3612                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3613                                         $oldSubpage->getDBkey() );
3614                         if ( $oldSubpage->isTalkPage() ) {
3615                                 $newNs = $nt->getTalkPage()->getNamespace();
3616                         } else {
3617                                 $newNs = $nt->getSubjectPage()->getNamespace();
3618                         }
3619                         # Bug 14385: we need makeTitleSafe because the new page names may
3620                         # be longer than 255 characters.
3621                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3622
3623                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3624                         if ( $success === true ) {
3625                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3626                         } else {
3627                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3628                         }
3629                 }
3630                 return $retval;
3631         }
3632
3633         /**
3634          * Checks if this page is just a one-rev redirect.
3635          * Adds lock, so don't use just for light purposes.
3636          *
3637          * @return Bool
3638          */
3639         public function isSingleRevRedirect() {
3640                 $dbw = wfGetDB( DB_MASTER );
3641                 # Is it a redirect?
3642                 $row = $dbw->selectRow( 'page',
3643                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3644                         $this->pageCond(),
3645                         __METHOD__,
3646                         array( 'FOR UPDATE' )
3647                 );
3648                 # Cache some fields we may want
3649                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3650                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3651                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3652                 if ( !$this->mRedirect ) {
3653                         return false;
3654                 }
3655                 # Does the article have a history?
3656                 $row = $dbw->selectField( array( 'page', 'revision' ),
3657                         'rev_id',
3658                         array( 'page_namespace' => $this->getNamespace(),
3659                                 'page_title' => $this->getDBkey(),
3660                                 'page_id=rev_page',
3661                                 'page_latest != rev_id'
3662                         ),
3663                         __METHOD__,
3664                         array( 'FOR UPDATE' )
3665                 );
3666                 # Return true if there was no history
3667                 return ( $row === false );
3668         }
3669
3670         /**
3671          * Checks if $this can be moved to a given Title
3672          * - Selects for update, so don't call it unless you mean business
3673          *
3674          * @param $nt Title the new title to check
3675          * @return Bool
3676          */
3677         public function isValidMoveTarget( $nt ) {
3678                 # Is it an existing file?
3679                 if ( $nt->getNamespace() == NS_FILE ) {
3680                         $file = wfLocalFile( $nt );
3681                         if ( $file->exists() ) {
3682                                 wfDebug( __METHOD__ . ": file exists\n" );
3683                                 return false;
3684                         }
3685                 }
3686                 # Is it a redirect with no history?
3687                 if ( !$nt->isSingleRevRedirect() ) {
3688                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3689                         return false;
3690                 }
3691                 # Get the article text
3692                 $rev = Revision::newFromTitle( $nt );
3693                 if( !is_object( $rev ) ){
3694                         return false;
3695                 }
3696                 $text = $rev->getText();
3697                 # Does the redirect point to the source?
3698                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3699                 $m = array();
3700                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3701                         $redirTitle = Title::newFromText( $m[1] );
3702                         if ( !is_object( $redirTitle ) ||
3703                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3704                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3705                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3706                                 return false;
3707                         }
3708                 } else {
3709                         # Fail safe
3710                         wfDebug( __METHOD__ . ": failsafe\n" );
3711                         return false;
3712                 }
3713                 return true;
3714         }
3715
3716         /**
3717          * Can this title be added to a user's watchlist?
3718          *
3719          * @return Bool TRUE or FALSE
3720          */
3721         public function isWatchable() {
3722                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3723         }
3724
3725         /**
3726          * Get categories to which this Title belongs and return an array of
3727          * categories' names.
3728          *
3729          * @return Array of parents in the form:
3730          *        $parent => $currentarticle
3731          */
3732         public function getParentCategories() {
3733                 global $wgContLang;
3734
3735                 $data = array();
3736
3737                 $titleKey = $this->getArticleId();
3738
3739                 if ( $titleKey === 0 ) {
3740                         return $data;
3741                 }
3742
3743                 $dbr = wfGetDB( DB_SLAVE );
3744
3745                 $res = $dbr->select( 'categorylinks', '*',
3746                         array(
3747                                 'cl_from' => $titleKey,
3748                         ),
3749                         __METHOD__,
3750                         array()
3751                 );
3752
3753                 if ( $dbr->numRows( $res ) > 0 ) {
3754                         foreach ( $res as $row ) {
3755                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3756                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3757                         }
3758                 }
3759                 return $data;
3760         }
3761
3762         /**
3763          * Get a tree of parent categories
3764          *
3765          * @param $children Array with the children in the keys, to check for circular refs
3766          * @return Array Tree of parent categories
3767          */
3768         public function getParentCategoryTree( $children = array() ) {
3769                 $stack = array();
3770                 $parents = $this->getParentCategories();
3771
3772                 if ( $parents ) {
3773                         foreach ( $parents as $parent => $current ) {
3774                                 if ( array_key_exists( $parent, $children ) ) {
3775                                         # Circular reference
3776                                         $stack[$parent] = array();
3777                                 } else {
3778                                         $nt = Title::newFromText( $parent );
3779                                         if ( $nt ) {
3780                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3781                                         }
3782                                 }
3783                         }
3784                 }
3785
3786                 return $stack;
3787         }
3788
3789         /**
3790          * Get an associative array for selecting this title from
3791          * the "page" table
3792          *
3793          * @return Array suitable for the $where parameter of DB::select()
3794          */
3795         public function pageCond() {
3796                 if ( $this->mArticleID > 0 ) {
3797                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3798                         return array( 'page_id' => $this->mArticleID );
3799                 } else {
3800                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3801                 }
3802         }
3803
3804         /**
3805          * Get the revision ID of the previous revision
3806          *
3807          * @param $revId Int Revision ID. Get the revision that was before this one.
3808          * @param $flags Int Title::GAID_FOR_UPDATE
3809          * @return Int|Bool Old revision ID, or FALSE if none exists
3810          */
3811         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3812                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3813                 return $db->selectField( 'revision', 'rev_id',
3814                         array(
3815                                 'rev_page' => $this->getArticleId( $flags ),
3816                                 'rev_id < ' . intval( $revId )
3817                         ),
3818                         __METHOD__,
3819                         array( 'ORDER BY' => 'rev_id DESC' )
3820                 );
3821         }
3822
3823         /**
3824          * Get the revision ID of the next revision
3825          *
3826          * @param $revId Int Revision ID. Get the revision that was after this one.
3827          * @param $flags Int Title::GAID_FOR_UPDATE
3828          * @return Int|Bool Next revision ID, or FALSE if none exists
3829          */
3830         public function getNextRevisionID( $revId, $flags = 0 ) {
3831                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3832                 return $db->selectField( 'revision', 'rev_id',
3833                         array(
3834                                 'rev_page' => $this->getArticleId( $flags ),
3835                                 'rev_id > ' . intval( $revId )
3836                         ),
3837                         __METHOD__,
3838                         array( 'ORDER BY' => 'rev_id' )
3839                 );
3840         }
3841
3842         /**
3843          * Get the first revision of the page
3844          *
3845          * @param $flags Int Title::GAID_FOR_UPDATE
3846          * @return Revision|Null if page doesn't exist
3847          */
3848         public function getFirstRevision( $flags = 0 ) {
3849                 $pageId = $this->getArticleId( $flags );
3850                 if ( $pageId ) {
3851                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3852                         $row = $db->selectRow( 'revision', '*',
3853                                 array( 'rev_page' => $pageId ),
3854                                 __METHOD__,
3855                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3856                         );
3857                         if ( $row ) {
3858                                 return new Revision( $row );
3859                         }
3860                 }
3861                 return null;
3862         }
3863
3864         /**
3865          * Get the oldest revision timestamp of this page
3866          *
3867          * @param $flags Int Title::GAID_FOR_UPDATE
3868          * @return String: MW timestamp
3869          */
3870         public function getEarliestRevTime( $flags = 0 ) {
3871                 $rev = $this->getFirstRevision( $flags );
3872                 return $rev ? $rev->getTimestamp() : null;
3873         }
3874
3875         /**
3876          * Check if this is a new page
3877          *
3878          * @return bool
3879          */
3880         public function isNewPage() {
3881                 $dbr = wfGetDB( DB_SLAVE );
3882                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3883         }
3884
3885         /**
3886          * Get the number of revisions between the given revision.
3887          * Used for diffs and other things that really need it.
3888          *
3889          * @param $old int|Revision Old revision or rev ID (first before range)
3890          * @param $new int|Revision New revision or rev ID (first after range)
3891          * @return Int Number of revisions between these revisions.
3892          */
3893         public function countRevisionsBetween( $old, $new ) {
3894                 if ( !( $old instanceof Revision ) ) {
3895                         $old = Revision::newFromTitle( $this, (int)$old );
3896                 }
3897                 if ( !( $new instanceof Revision ) ) {
3898                         $new = Revision::newFromTitle( $this, (int)$new );
3899                 }
3900                 if ( !$old || !$new ) {
3901                         return 0; // nothing to compare
3902                 }
3903                 $dbr = wfGetDB( DB_SLAVE );
3904                 return (int)$dbr->selectField( 'revision', 'count(*)',
3905                         array(
3906                                 'rev_page' => $this->getArticleId(),
3907                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3908                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3909                         ),
3910                         __METHOD__
3911                 );
3912         }
3913
3914         /**
3915          * Get the number of authors between the given revision IDs.
3916          * Used for diffs and other things that really need it.
3917          *
3918          * @param $old int|Revision Old revision or rev ID (first before range)
3919          * @param $new int|Revision New revision or rev ID (first after range)
3920          * @param $limit Int Maximum number of authors
3921          * @return Int Number of revision authors between these revisions.
3922          */
3923         public function countAuthorsBetween( $old, $new, $limit ) {
3924                 if ( !( $old instanceof Revision ) ) {
3925                         $old = Revision::newFromTitle( $this, (int)$old );
3926                 }
3927                 if ( !( $new instanceof Revision ) ) {
3928                         $new = Revision::newFromTitle( $this, (int)$new );
3929                 }
3930                 if ( !$old || !$new ) {
3931                         return 0; // nothing to compare
3932                 }
3933                 $dbr = wfGetDB( DB_SLAVE );
3934                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3935                         array(
3936                                 'rev_page' => $this->getArticleID(),
3937                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3938                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3939                         ), __METHOD__,
3940                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3941                 );
3942                 return (int)$dbr->numRows( $res );
3943         }
3944
3945         /**
3946          * Compare with another title.
3947          *
3948          * @param $title Title
3949          * @return Bool
3950          */
3951         public function equals( Title $title ) {
3952                 // Note: === is necessary for proper matching of number-like titles.
3953                 return $this->getInterwiki() === $title->getInterwiki()
3954                         && $this->getNamespace() == $title->getNamespace()
3955                         && $this->getDBkey() === $title->getDBkey();
3956         }
3957
3958         /**
3959          * Check if this title is a subpage of another title
3960          *
3961          * @param $title Title
3962          * @return Bool
3963          */
3964         public function isSubpageOf( Title $title ) {
3965                 return $this->getInterwiki() === $title->getInterwiki()
3966                         && $this->getNamespace() == $title->getNamespace()
3967                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
3968         }
3969
3970         /**
3971          * Callback for usort() to do title sorts by (namespace, title)
3972          *
3973          * @param $a Title
3974          * @param $b Title
3975          *
3976          * @return Integer: result of string comparison, or namespace comparison
3977          */
3978         public static function compare( $a, $b ) {
3979                 if ( $a->getNamespace() == $b->getNamespace() ) {
3980                         return strcmp( $a->getText(), $b->getText() );
3981                 } else {
3982                         return $a->getNamespace() - $b->getNamespace();
3983                 }
3984         }
3985
3986         /**
3987          * Return a string representation of this title
3988          *
3989          * @return String representation of this title
3990          */
3991         public function __toString() {
3992                 return $this->getPrefixedText();
3993         }
3994
3995         /**
3996          * Check if page exists.  For historical reasons, this function simply
3997          * checks for the existence of the title in the page table, and will
3998          * thus return false for interwiki links, special pages and the like.
3999          * If you want to know if a title can be meaningfully viewed, you should
4000          * probably call the isKnown() method instead.
4001          *
4002          * @return Bool
4003          */
4004         public function exists() {
4005                 return $this->getArticleId() != 0;
4006         }
4007
4008         /**
4009          * Should links to this title be shown as potentially viewable (i.e. as
4010          * "bluelinks"), even if there's no record by this title in the page
4011          * table?
4012          *
4013          * This function is semi-deprecated for public use, as well as somewhat
4014          * misleadingly named.  You probably just want to call isKnown(), which
4015          * calls this function internally.
4016          *
4017          * (ISSUE: Most of these checks are cheap, but the file existence check
4018          * can potentially be quite expensive.  Including it here fixes a lot of
4019          * existing code, but we might want to add an optional parameter to skip
4020          * it and any other expensive checks.)
4021          *
4022          * @return Bool
4023          */
4024         public function isAlwaysKnown() {
4025                 if ( $this->mInterwiki != '' ) {
4026                         return true;  // any interwiki link might be viewable, for all we know
4027                 }
4028                 switch( $this->mNamespace ) {
4029                         case NS_MEDIA:
4030                         case NS_FILE:
4031                                 // file exists, possibly in a foreign repo
4032                                 return (bool)wfFindFile( $this );
4033                         case NS_SPECIAL:
4034                                 // valid special page
4035                                 return SpecialPageFactory::exists( $this->getDBkey() );
4036                         case NS_MAIN:
4037                                 // selflink, possibly with fragment
4038                                 return $this->mDbkeyform == '';
4039                         case NS_MEDIAWIKI:
4040                                 // known system message
4041                                 return $this->hasSourceText() !== false;
4042                         default:
4043                                 return false;
4044                 }
4045         }
4046
4047         /**
4048          * Does this title refer to a page that can (or might) be meaningfully
4049          * viewed?  In particular, this function may be used to determine if
4050          * links to the title should be rendered as "bluelinks" (as opposed to
4051          * "redlinks" to non-existent pages).
4052          *
4053          * @return Bool
4054          */
4055         public function isKnown() {
4056                 return $this->isAlwaysKnown() || $this->exists();
4057         }
4058
4059         /**
4060          * Does this page have source text?
4061          *
4062          * @return Boolean
4063          */
4064         public function hasSourceText() {
4065                 if ( $this->exists() ) {
4066                         return true;
4067                 }
4068
4069                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4070                         // If the page doesn't exist but is a known system message, default
4071                         // message content will be displayed, same for language subpages-
4072                         // Use always content language to avoid loading hundreds of languages
4073                         // to get the link color.
4074                         global $wgContLang;
4075                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4076                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4077                         return $message->exists();
4078                 }
4079
4080                 return false;
4081         }
4082
4083         /**
4084          * Get the default message text or false if the message doesn't exist
4085          *
4086          * @return String or false
4087          */
4088         public function getDefaultMessageText() {
4089                 global $wgContLang;
4090
4091                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4092                         return false;
4093                 }
4094
4095                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4096                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4097
4098                 if ( $message->exists() ) {
4099                         return $message->plain();
4100                 } else {
4101                         return false;
4102                 }
4103         }
4104
4105         /**
4106          * Is this in a namespace that allows actual pages?
4107          *
4108          * @return Bool
4109          * @internal note -- uses hardcoded namespace index instead of constants
4110          */
4111         public function canExist() {
4112                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
4113         }
4114
4115         /**
4116          * Update page_touched timestamps and send squid purge messages for
4117          * pages linking to this title. May be sent to the job queue depending
4118          * on the number of links. Typically called on create and delete.
4119          */
4120         public function touchLinks() {
4121                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4122                 $u->doUpdate();
4123
4124                 if ( $this->getNamespace() == NS_CATEGORY ) {
4125                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4126                         $u->doUpdate();
4127                 }
4128         }
4129
4130         /**
4131          * Get the last touched timestamp
4132          *
4133          * @param $db DatabaseBase: optional db
4134          * @return String last-touched timestamp
4135          */
4136         public function getTouched( $db = null ) {
4137                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4138                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4139                 return $touched;
4140         }
4141
4142         /**
4143          * Get the timestamp when this page was updated since the user last saw it.
4144          *
4145          * @param $user User
4146          * @return String|Null
4147          */
4148         public function getNotificationTimestamp( $user = null ) {
4149                 global $wgUser, $wgShowUpdatedMarker;
4150                 // Assume current user if none given
4151                 if ( !$user ) {
4152                         $user = $wgUser;
4153                 }
4154                 // Check cache first
4155                 $uid = $user->getId();
4156                 // avoid isset here, as it'll return false for null entries
4157                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4158                         return $this->mNotificationTimestamp[$uid];
4159                 }
4160                 if ( !$uid || !$wgShowUpdatedMarker ) {
4161                         return $this->mNotificationTimestamp[$uid] = false;
4162                 }
4163                 // Don't cache too much!
4164                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4165                         $this->mNotificationTimestamp = array();
4166                 }
4167                 $dbr = wfGetDB( DB_SLAVE );
4168                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4169                         'wl_notificationtimestamp',
4170                         array( 'wl_namespace' => $this->getNamespace(),
4171                                 'wl_title' => $this->getDBkey(),
4172                                 'wl_user' => $user->getId()
4173                         ),
4174                         __METHOD__
4175                 );
4176                 return $this->mNotificationTimestamp[$uid];
4177         }
4178
4179         /**
4180          * Generate strings used for xml 'id' names in monobook tabs
4181          *
4182          * @param $prepend string defaults to 'nstab-'
4183          * @return String XML 'id' name
4184          */
4185         public function getNamespaceKey( $prepend = 'nstab-' ) {
4186                 global $wgContLang;
4187                 // Gets the subject namespace if this title
4188                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4189                 // Checks if cononical namespace name exists for namespace
4190                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4191                         // Uses canonical namespace name
4192                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4193                 } else {
4194                         // Uses text of namespace
4195                         $namespaceKey = $this->getSubjectNsText();
4196                 }
4197                 // Makes namespace key lowercase
4198                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4199                 // Uses main
4200                 if ( $namespaceKey == '' ) {
4201                         $namespaceKey = 'main';
4202                 }
4203                 // Changes file to image for backwards compatibility
4204                 if ( $namespaceKey == 'file' ) {
4205                         $namespaceKey = 'image';
4206                 }
4207                 return $prepend . $namespaceKey;
4208         }
4209
4210         /**
4211          * Returns true if this is a special page.
4212          *
4213          * @return boolean
4214          */
4215         public function isSpecialPage() {
4216                 return $this->getNamespace() == NS_SPECIAL;
4217         }
4218
4219         /**
4220          * Returns true if this title resolves to the named special page
4221          *
4222          * @param $name String The special page name
4223          * @return boolean
4224          */
4225         public function isSpecial( $name ) {
4226                 if ( $this->isSpecialPage() ) {
4227                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4228                         if ( $name == $thisName ) {
4229                                 return true;
4230                         }
4231                 }
4232                 return false;
4233         }
4234
4235         /**
4236          * If the Title refers to a special page alias which is not the local default, resolve
4237          * the alias, and localise the name as necessary.  Otherwise, return $this
4238          *
4239          * @return Title
4240          */
4241         public function fixSpecialName() {
4242                 if ( $this->isSpecialPage() ) {
4243                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4244                         if ( $canonicalName ) {
4245                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
4246                                 if ( $localName != $this->mDbkeyform ) {
4247                                         return Title::makeTitle( NS_SPECIAL, $localName );
4248                                 }
4249                         }
4250                 }
4251                 return $this;
4252         }
4253
4254         /**
4255          * Is this Title in a namespace which contains content?
4256          * In other words, is this a content page, for the purposes of calculating
4257          * statistics, etc?
4258          *
4259          * @return Boolean
4260          */
4261         public function isContentPage() {
4262                 return MWNamespace::isContent( $this->getNamespace() );
4263         }
4264
4265         /**
4266          * Get all extant redirects to this Title
4267          *
4268          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4269          * @return Array of Title redirects to this title
4270          */
4271         public function getRedirectsHere( $ns = null ) {
4272                 $redirs = array();
4273
4274                 $dbr = wfGetDB( DB_SLAVE );
4275                 $where = array(
4276                         'rd_namespace' => $this->getNamespace(),
4277                         'rd_title' => $this->getDBkey(),
4278                         'rd_from = page_id'
4279                 );
4280                 if ( !is_null( $ns ) ) {
4281                         $where['page_namespace'] = $ns;
4282                 }
4283
4284                 $res = $dbr->select(
4285                         array( 'redirect', 'page' ),
4286                         array( 'page_namespace', 'page_title' ),
4287                         $where,
4288                         __METHOD__
4289                 );
4290
4291                 foreach ( $res as $row ) {
4292                         $redirs[] = self::newFromRow( $row );
4293                 }
4294                 return $redirs;
4295         }
4296
4297         /**
4298          * Check if this Title is a valid redirect target
4299          *
4300          * @return Bool
4301          */
4302         public function isValidRedirectTarget() {
4303                 global $wgInvalidRedirectTargets;
4304
4305                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4306                 if ( $this->isSpecial( 'Userlogout' ) ) {
4307                         return false;
4308                 }
4309
4310                 foreach ( $wgInvalidRedirectTargets as $target ) {
4311                         if ( $this->isSpecial( $target ) ) {
4312                                 return false;
4313                         }
4314                 }
4315
4316                 return true;
4317         }
4318
4319         /**
4320          * Get a backlink cache object
4321          *
4322          * @return BacklinkCache
4323          */
4324         function getBacklinkCache() {
4325                 if ( is_null( $this->mBacklinkCache ) ) {
4326                         $this->mBacklinkCache = new BacklinkCache( $this );
4327                 }
4328                 return $this->mBacklinkCache;
4329         }
4330
4331         /**
4332          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4333          *
4334          * @return Boolean
4335          */
4336         public function canUseNoindex() {
4337                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4338
4339                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4340                         ? $wgContentNamespaces
4341                         : $wgExemptFromUserRobotsControl;
4342
4343                 return !in_array( $this->mNamespace, $bannedNamespaces );
4344
4345         }
4346
4347         /**
4348          * Returns restriction types for the current Title
4349          *
4350          * @return array applicable restriction types
4351          */
4352         public function getRestrictionTypes() {
4353                 if ( $this->isSpecialPage() ) {
4354                         return array();
4355                 }
4356
4357                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4358
4359                 if ( $this->getNamespace() != NS_FILE ) {
4360                         # Remove the upload restriction for non-file titles
4361                         $types = array_diff( $types, array( 'upload' ) );
4362                 }
4363
4364                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4365
4366                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
4367                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
4368
4369                 return $types;
4370         }
4371         /**
4372          * Get a filtered list of all restriction types supported by this wiki.
4373          * @param bool $exists True to get all restriction types that apply to
4374          * titles that do exist, False for all restriction types that apply to
4375          * titles that do not exist
4376          * @return array
4377          */
4378         public static function getFilteredRestrictionTypes( $exists = true ) {
4379                 global $wgRestrictionTypes;
4380                 $types = $wgRestrictionTypes;
4381                 if ( $exists ) {
4382                         # Remove the create restriction for existing titles
4383                         $types = array_diff( $types, array( 'create' ) );
4384                 } else {
4385                         # Only the create and upload restrictions apply to non-existing titles
4386                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4387                 }
4388                 return $types;
4389         }
4390
4391         /**
4392          * Returns the raw sort key to be used for categories, with the specified
4393          * prefix.  This will be fed to Collation::getSortKey() to get a
4394          * binary sortkey that can be used for actual sorting.
4395          *
4396          * @param $prefix string The prefix to be used, specified using
4397          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4398          *   prefix.
4399          * @return string
4400          */
4401         public function getCategorySortkey( $prefix = '' ) {
4402                 $unprefixed = $this->getText();
4403
4404                 // Anything that uses this hook should only depend
4405                 // on the Title object passed in, and should probably
4406                 // tell the users to run updateCollations.php --force
4407                 // in order to re-sort existing category relations.
4408                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4409                 if ( $prefix !== '' ) {
4410                         # Separate with a line feed, so the unprefixed part is only used as
4411                         # a tiebreaker when two pages have the exact same prefix.
4412                         # In UCA, tab is the only character that can sort above LF
4413                         # so we strip both of them from the original prefix.
4414                         $prefix = strtr( $prefix, "\n\t", '  ' );
4415                         return "$prefix\n$unprefixed";
4416                 }
4417                 return $unprefixed;
4418         }
4419
4420         /**
4421          * Get the language in which the content of this page is written.
4422          * Defaults to $wgContLang, but in certain cases it can be e.g.
4423          * $wgLang (such as special pages, which are in the user language).
4424          *
4425          * @since 1.18
4426          * @return object Language
4427          */
4428         public function getPageLanguage() {
4429                 global $wgLang;
4430                 if ( $this->isSpecialPage() ) {
4431                         // special pages are in the user language
4432                         return $wgLang;
4433                 } elseif ( $this->isCssOrJsPage() ) {
4434                         // css/js should always be LTR and is, in fact, English
4435                         return wfGetLangObj( 'en' );
4436                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4437                         // Parse mediawiki messages with correct target language
4438                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4439                         return wfGetLangObj( $lang );
4440                 }
4441                 global $wgContLang;
4442                 // If nothing special, it should be in the wiki content language
4443                 $pageLang = $wgContLang;
4444                 // Hook at the end because we don't want to override the above stuff
4445                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4446                 return wfGetLangObj( $pageLang );
4447         }
4448 }