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         private $mEstimateRevisions;      // /< Estimated number of revisions; null of 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                 } else { // page not found
 277                         $this->mArticleID = 0;
 278                         $this->mLength = 0;
 279                         $this->mRedirect = false;
 280                         $this->mLatestID = 0;
 281                 }
 282         }
 283
 284         /**
 285          * Create a new Title from a namespace index and a DB key.
 286          * It's assumed that $ns and $title are *valid*, for instance when
 287          * they came directly from the database or a special page name.
 288          * For convenience, spaces are converted to underscores so that
 289          * eg user_text fields can be used directly.
 290          *
 291          * @param $ns Int the namespace of the article
 292          * @param $title String the unprefixed database key form
 293          * @param $fragment String the link fragment (after the "#")
 294          * @param $interwiki String the interwiki prefix
 295          * @return Title the new object
 296          */
 297         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 298                 $t = new Title();
 299                 $t->mInterwiki = $interwiki;
 300                 $t->mFragment = $fragment;
 301                 $t->mNamespace = $ns = intval( $ns );
 302                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 303                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 304                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 305                 $t->mTextform = str_replace( '_', ' ', $title );
 306                 return $t;
 307         }
 308
 309         /**
 310          * Create a new Title from a namespace index and a DB key.
 311          * The parameters will be checked for validity, which is a bit slower
 312          * than makeTitle() but safer for user-provided data.
 313          *
 314          * @param $ns Int the namespace of the article
 315          * @param $title String database key form
 316          * @param $fragment String the link fragment (after the "#")
 317          * @param $interwiki String interwiki prefix
 318          * @return Title the new object, or NULL on an error
 319          */
 320         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 321                 $t = new Title();
 322                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 323                 if ( $t->secureAndSplit() ) {
 324                         return $t;
 325                 } else {
 326                         return null;
 327                 }
 328         }
 329
 330         /**
 331          * Create a new Title for the Main Page
 332          *
 333          * @return Title the new object
 334          */
 335         public static function newMainPage() {
 336                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 337                 // Don't give fatal errors if the message is broken
 338                 if ( !$title ) {
 339                         $title = Title::newFromText( 'Main Page' );
 340                 }
 341                 return $title;
 342         }
 343
 344         /**
 345          * Extract a redirect destination from a string and return the
 346          * Title, or null if the text doesn't contain a valid redirect
 347          * This will only return the very next target, useful for
 348          * the redirect table and other checks that don't need full recursion
 349          *
 350          * @param $text String: Text with possible redirect
 351          * @return Title: The corresponding Title
 352          */
 353         public static function newFromRedirect( $text ) {
 354                 return self::newFromRedirectInternal( $text );
 355         }
 356
 357         /**
 358          * Extract a redirect destination from a string and return the
 359          * Title, or null if the text doesn't contain a valid redirect
 360          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 361          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 362          *
 363          * @param $text String Text with possible redirect
 364          * @return Title
 365          */
 366         public static function newFromRedirectRecurse( $text ) {
 367                 $titles = self::newFromRedirectArray( $text );
 368                 return $titles ? array_pop( $titles ) : null;
 369         }
 370
 371         /**
 372          * Extract a redirect destination from a string and return an
 373          * array of Titles, or null if the text doesn't contain a valid redirect
 374          * The last element in the array is the final destination after all redirects
 375          * have been resolved (up to $wgMaxRedirects times)
 376          *
 377          * @param $text String Text with possible redirect
 378          * @return Array of Titles, with the destination last
 379          */
 380         public static function newFromRedirectArray( $text ) {
 381                 global $wgMaxRedirects;
 382                 $title = self::newFromRedirectInternal( $text );
 383                 if ( is_null( $title ) ) {
 384                         return null;
 385                 }
 386                 // recursive check to follow double redirects
 387                 $recurse = $wgMaxRedirects;
 388                 $titles = array( $title );
 389                 while ( --$recurse > 0 ) {
 390                         if ( $title->isRedirect() ) {
 391                                 $page = WikiPage::factory( $title );
 392                                 $newtitle = $page->getRedirectTarget();
 393                         } else {
 394                                 break;
 395                         }
 396                         // Redirects to some special pages are not permitted
 397                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 398                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 399                                 $title = $newtitle;
 400                                 $titles[] = $newtitle;
 401                         } else {
 402                                 break;
 403                         }
 404                 }
 405                 return $titles;
 406         }
 407
 408         /**
 409          * Really extract the redirect destination
 410          * Do not call this function directly, use one of the newFromRedirect* functions above
 411          *
 412          * @param $text String Text with possible redirect
 413          * @return Title
 414          */
 415         protected static function newFromRedirectInternal( $text ) {
 416                 global $wgMaxRedirects;
 417                 if ( $wgMaxRedirects < 1 ) {
 418                         //redirects are disabled, so quit early
 419                         return null;
 420                 }
 421                 $redir = MagicWord::get( 'redirect' );
 422                 $text = trim( $text );
 423                 if ( $redir->matchStartAndRemove( $text ) ) {
 424                         // Extract the first link and see if it's usable
 425                         // Ensure that it really does come directly after #REDIRECT
 426                         // Some older redirects included a colon, so don't freak about that!
 427                         $m = array();
 428                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 429                                 // Strip preceding colon used to "escape" categories, etc.
 430                                 // and URL-decode links
 431                                 if ( strpos( $m[1], '%' ) !== false ) {
 432                                         // Match behavior of inline link parsing here;
 433                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 434                                 }
 435                                 $title = Title::newFromText( $m[1] );
 436                                 // If the title is a redirect to bad special pages or is invalid, return null
 437                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 438                                         return null;
 439                                 }
 440                                 return $title;
 441                         }
 442                 }
 443                 return null;
 444         }
 445
 446         /**
 447          * Get the prefixed DB key associated with an ID
 448          *
 449          * @param $id Int the page_id of the article
 450          * @return Title an object representing the article, or NULL if no such article was found
 451          */
 452         public static function nameOf( $id ) {
 453                 $dbr = wfGetDB( DB_SLAVE );
 454
 455                 $s = $dbr->selectRow(
 456                         'page',
 457                         array( 'page_namespace', 'page_title' ),
 458                         array( 'page_id' => $id ),
 459                         __METHOD__
 460                 );
 461                 if ( $s === false ) {
 462                         return null;
 463                 }
 464
 465                 $n = self::makeName( $s->page_namespace, $s->page_title );
 466                 return $n;
 467         }
 468
 469         /**
 470          * Get a regex character class describing the legal characters in a link
 471          *
 472          * @return String the list of characters, not delimited
 473          */
 474         public static function legalChars() {
 475                 global $wgLegalTitleChars;
 476                 return $wgLegalTitleChars;
 477         }
 478
 479         /**
 480          * Returns a simple regex that will match on characters and sequences invalid in titles.
 481          * Note that this doesn't pick up many things that could be wrong with titles, but that
 482          * replacing this regex with something valid will make many titles valid.
 483          *
 484          * @return String regex string
 485          */
 486         static function getTitleInvalidRegex() {
 487                 static $rxTc = false;
 488                 if ( !$rxTc ) {
 489                         # Matching titles will be held as illegal.
 490                         $rxTc = '/' .
 491                                 # Any character not allowed is forbidden...
 492                                 '[^' . self::legalChars() . ']' .
 493                                 # URL percent encoding sequences interfere with the ability
 494                                 # to round-trip titles -- you can't link to them consistently.
 495                                 '|%[0-9A-Fa-f]{2}' .
 496                                 # XML/HTML character references produce similar issues.
 497                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 498                                 '|&#[0-9]+;' .
 499                                 '|&#x[0-9A-Fa-f]+;' .
 500                                 '/S';
 501                 }
 502
 503                 return $rxTc;
 504         }
 505
 506         /**
 507          * Get a string representation of a title suitable for
 508          * including in a search index
 509          *
 510          * @param $ns Int a namespace index
 511          * @param $title String text-form main part
 512          * @return String a stripped-down title string ready for the search index
 513          */
 514         public static function indexTitle( $ns, $title ) {
 515                 global $wgContLang;
 516
 517                 $lc = SearchEngine::legalSearchChars() . '&#;';
 518                 $t = $wgContLang->normalizeForSearch( $title );
 519                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 520                 $t = $wgContLang->lc( $t );
 521
 522                 # Handle 's, s'
 523                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 524                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 525
 526                 $t = preg_replace( "/\\s+/", ' ', $t );
 527
 528                 if ( $ns == NS_FILE ) {
 529                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 530                 }
 531                 return trim( $t );
 532         }
 533
 534         /**
 535          * Make a prefixed DB key from a DB key and a namespace index
 536          *
 537          * @param $ns Int numerical representation of the namespace
 538          * @param $title String the DB key form the title
 539          * @param $fragment String The link fragment (after the "#")
 540          * @param $interwiki String The interwiki prefix
 541          * @return String the prefixed form of the title
 542          */
 543         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 544                 global $wgContLang;
 545
 546                 $namespace = $wgContLang->getNsText( $ns );
 547                 $name = $namespace == '' ? $title : "$namespace:$title";
 548                 if ( strval( $interwiki ) != '' ) {
 549                         $name = "$interwiki:$name";
 550                 }
 551                 if ( strval( $fragment ) != '' ) {
 552                         $name .= '#' . $fragment;
 553                 }
 554                 return $name;
 555         }
 556
 557         /**
 558          * Escape a text fragment, say from a link, for a URL
 559          *
 560          * @param $fragment string containing a URL or link fragment (after the "#")
 561          * @return String: escaped string
 562          */
 563         static function escapeFragmentForURL( $fragment ) {
 564                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 565                 # fragments appear not to work in IE (at least up to 7) or in at least
 566                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 567                 # to care if they aren't encoded.
 568                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 569         }
 570
 571         /**
 572          * Callback for usort() to do title sorts by (namespace, title)
 573          *
 574          * @param $a Title
 575          * @param $b Title
 576          *
 577          * @return Integer: result of string comparison, or namespace comparison
 578          */
 579         public static function compare( $a, $b ) {
 580                 if ( $a->getNamespace() == $b->getNamespace() ) {
 581                         return strcmp( $a->getText(), $b->getText() );
 582                 } else {
 583                         return $a->getNamespace() - $b->getNamespace();
 584                 }
 585         }
 586
 587         /**
 588          * Determine whether the object refers to a page within
 589          * this project.
 590          *
 591          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 592          */
 593         public function isLocal() {
 594                 if ( $this->mInterwiki != '' ) {
 595                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 596                 } else {
 597                         return true;
 598                 }
 599         }
 600
 601         /**
 602          * Is this Title interwiki?
 603          *
 604          * @return Bool
 605          */
 606         public function isExternal() {
 607                 return ( $this->mInterwiki != '' );
 608         }
 609
 610         /**
 611          * Get the interwiki prefix (or null string)
 612          *
 613          * @return String Interwiki prefix
 614          */
 615         public function getInterwiki() {
 616                 return $this->mInterwiki;
 617         }
 618
 619         /**
 620          * Determine whether the object refers to a page within
 621          * this project and is transcludable.
 622          *
 623          * @return Bool TRUE if this is transcludable
 624          */
 625         public function isTrans() {
 626                 if ( $this->mInterwiki == '' ) {
 627                         return false;
 628                 }
 629
 630                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 631         }
 632
 633         /**
 634          * Returns the DB name of the distant wiki which owns the object.
 635          *
 636          * @return String the DB name
 637          */
 638         public function getTransWikiID() {
 639                 if ( $this->mInterwiki == '' ) {
 640                         return false;
 641                 }
 642
 643                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 644         }
 645
 646         /**
 647          * Get the text form (spaces not underscores) of the main part
 648          *
 649          * @return String Main part of the title
 650          */
 651         public function getText() {
 652                 return $this->mTextform;
 653         }
 654
 655         /**
 656          * Get the URL-encoded form of the main part
 657          *
 658          * @return String Main part of the title, URL-encoded
 659          */
 660         public function getPartialURL() {
 661                 return $this->mUrlform;
 662         }
 663
 664         /**
 665          * Get the main part with underscores
 666          *
 667          * @return String: Main part of the title, with underscores
 668          */
 669         public function getDBkey() {
 670                 return $this->mDbkeyform;
 671         }
 672
 673         /**
 674          * Get the DB key with the initial letter case as specified by the user
 675          *
 676          * @return String DB key
 677          */
 678         function getUserCaseDBKey() {
 679                 return $this->mUserCaseDBKey;
 680         }
 681
 682         /**
 683          * Get the namespace index, i.e. one of the NS_xxxx constants.
 684          *
 685          * @return Integer: Namespace index
 686          */
 687         public function getNamespace() {
 688                 return $this->mNamespace;
 689         }
 690
 691         /**
 692          * Get the namespace text
 693          *
 694          * @return String: Namespace text
 695          */
 696         public function getNsText() {
 697                 global $wgContLang;
 698
 699                 if ( $this->mInterwiki != '' ) {
 700                         // This probably shouldn't even happen. ohh man, oh yuck.
 701                         // But for interwiki transclusion it sometimes does.
 702                         // Shit. Shit shit shit.
 703                         //
 704                         // Use the canonical namespaces if possible to try to
 705                         // resolve a foreign namespace.
 706                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 707                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 708                         }
 709                 }
 710
 711                 // Strip off subpages
 712                 $pagename = $this->getText();
 713                 if ( strpos( $pagename, '/' ) !== false ) {
 714                         list( $username , ) = explode( '/', $pagename, 2 );
 715                 } else {
 716                         $username = $pagename;
 717                 }
 718
 719                 if ( $wgContLang->needsGenderDistinction() &&
 720                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 721                         $gender = GenderCache::singleton()->getGenderOf( $username, __METHOD__ );
 722                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 723                 }
 724
 725                 return $wgContLang->getNsText( $this->mNamespace );
 726         }
 727
 728         /**
 729          * Get the namespace text of the subject (rather than talk) page
 730          *
 731          * @return String Namespace text
 732          */
 733         public function getSubjectNsText() {
 734                 global $wgContLang;
 735                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 736         }
 737
 738         /**
 739          * Get the namespace text of the talk page
 740          *
 741          * @return String Namespace text
 742          */
 743         public function getTalkNsText() {
 744                 global $wgContLang;
 745                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 746         }
 747
 748         /**
 749          * Could this title have a corresponding talk page?
 750          *
 751          * @return Bool TRUE or FALSE
 752          */
 753         public function canTalk() {
 754                 return( MWNamespace::canTalk( $this->mNamespace ) );
 755         }
 756
 757         /**
 758          * Is this in a namespace that allows actual pages?
 759          *
 760          * @return Bool
 761          * @internal note -- uses hardcoded namespace index instead of constants
 762          */
 763         public function canExist() {
 764                 return $this->mNamespace >= NS_MAIN;
 765         }
 766
 767         /**
 768          * Can this title be added to a user's watchlist?
 769          *
 770          * @return Bool TRUE or FALSE
 771          */
 772         public function isWatchable() {
 773                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 774         }
 775
 776         /**
 777          * Returns true if this is a special page.
 778          *
 779          * @return boolean
 780          */
 781         public function isSpecialPage() {
 782                 return $this->getNamespace() == NS_SPECIAL;
 783         }
 784
 785         /**
 786          * Returns true if this title resolves to the named special page
 787          *
 788          * @param $name String The special page name
 789          * @return boolean
 790          */
 791         public function isSpecial( $name ) {
 792                 if ( $this->isSpecialPage() ) {
 793                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 794                         if ( $name == $thisName ) {
 795                                 return true;
 796                         }
 797                 }
 798                 return false;
 799         }
 800
 801         /**
 802          * If the Title refers to a special page alias which is not the local default, resolve
 803          * the alias, and localise the name as necessary.  Otherwise, return $this
 804          *
 805          * @return Title
 806          */
 807         public function fixSpecialName() {
 808                 if ( $this->isSpecialPage() ) {
 809                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 810                         if ( $canonicalName ) {
 811                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 812                                 if ( $localName != $this->mDbkeyform ) {
 813                                         return Title::makeTitle( NS_SPECIAL, $localName );
 814                                 }
 815                         }
 816                 }
 817                 return $this;
 818         }
 819
 820         /**
 821          * Returns true if the title is inside the specified namespace.
 822          *
 823          * Please make use of this instead of comparing to getNamespace()
 824          * This function is much more resistant to changes we may make
 825          * to namespaces than code that makes direct comparisons.
 826          * @param $ns int The namespace
 827          * @return bool
 828          * @since 1.19
 829          */
 830         public function inNamespace( $ns ) {
 831                 return MWNamespace::equals( $this->getNamespace(), $ns );
 832         }
 833
 834         /**
 835          * Returns true if the title is inside one of the specified namespaces.
 836          *
 837          * @param ...$namespaces The namespaces to check for
 838          * @return bool
 839          * @since 1.19
 840          */
 841         public function inNamespaces( /* ... */ ) {
 842                 $namespaces = func_get_args();
 843                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 844                         $namespaces = $namespaces[0];
 845                 }
 846
 847                 foreach ( $namespaces as $ns ) {
 848                         if ( $this->inNamespace( $ns ) ) {
 849                                 return true;
 850                         }
 851                 }
 852
 853                 return false;
 854         }
 855
 856         /**
 857          * Returns true if the title has the same subject namespace as the
 858          * namespace specified.
 859          * For example this method will take NS_USER and return true if namespace
 860          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 861          * as their subject namespace.
 862          *
 863          * This is MUCH simpler than individually testing for equivilance
 864          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 865          * @since 1.19
 866          */
 867         public function hasSubjectNamespace( $ns ) {
 868                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 869         }
 870
 871         /**
 872          * Is this Title in a namespace which contains content?
 873          * In other words, is this a content page, for the purposes of calculating
 874          * statistics, etc?
 875          *
 876          * @return Boolean
 877          */
 878         public function isContentPage() {
 879                 return MWNamespace::isContent( $this->getNamespace() );
 880         }
 881
 882         /**
 883          * Would anybody with sufficient privileges be able to move this page?
 884          * Some pages just aren't movable.
 885          *
 886          * @return Bool TRUE or FALSE
 887          */
 888         public function isMovable() {
 889                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 890                         // Interwiki title or immovable namespace. Hooks don't get to override here
 891                         return false;
 892                 }
 893
 894                 $result = true;
 895                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 896                 return $result;
 897         }
 898
 899         /**
 900          * Is this the mainpage?
 901          * @note Title::newFromText seams to be sufficiently optimized by the title
 902          * cache that we don't need to over-optimize by doing direct comparisons and
 903          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 904          * ends up reporting something differently than $title->isMainPage();
 905          *
 906          * @since 1.18
 907          * @return Bool
 908          */
 909         public function isMainPage() {
 910                 return $this->equals( Title::newMainPage() );
 911         }
 912
 913         /**
 914          * Is this a subpage?
 915          *
 916          * @return Bool
 917          */
 918         public function isSubpage() {
 919                 return MWNamespace::hasSubpages( $this->mNamespace )
 920                         ? strpos( $this->getText(), '/' ) !== false
 921                         : false;
 922         }
 923
 924         /**
 925          * Is this a conversion table for the LanguageConverter?
 926          *
 927          * @return Bool
 928          */
 929         public function isConversionTable() {
 930                 return $this->getNamespace() == NS_MEDIAWIKI &&
 931                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 932         }
 933
 934         /**
 935          * Does that page contain wikitext, or it is JS, CSS or whatever?
 936          *
 937          * @return Bool
 938          */
 939         public function isWikitextPage() {
 940                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
 941                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
 942                 return $retval;
 943         }
 944
 945         /**
 946          * Could this page contain custom CSS or JavaScript, based
 947          * on the title?
 948          *
 949          * @return Bool
 950          */
 951         public function isCssOrJsPage() {
 952                 $retval = $this->mNamespace == NS_MEDIAWIKI
 953                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
 954                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
 955                 return $retval;
 956         }
 957
 958         /**
 959          * Is this a .css or .js subpage of a user page?
 960          * @return Bool
 961          */
 962         public function isCssJsSubpage() {
 963                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
 964         }
 965
 966         /**
 967          * Trim down a .css or .js subpage title to get the corresponding skin name
 968          *
 969          * @return string containing skin name from .css or .js subpage title
 970          */
 971         public function getSkinFromCssJsSubpage() {
 972                 $subpage = explode( '/', $this->mTextform );
 973                 $subpage = $subpage[ count( $subpage ) - 1 ];
 974                 $lastdot = strrpos( $subpage, '.' );
 975                 if ( $lastdot === false )
 976                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 977                 return substr( $subpage, 0, $lastdot );
 978         }
 979
 980         /**
 981          * Is this a .css subpage of a user page?
 982          *
 983          * @return Bool
 984          */
 985         public function isCssSubpage() {
 986                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
 987         }
 988
 989         /**
 990          * Is this a .js subpage of a user page?
 991          *
 992          * @return Bool
 993          */
 994         public function isJsSubpage() {
 995                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
 996         }
 997
 998         /**
 999          * Is this a talk page of some sort?
1000          *
1001          * @return Bool
1002          */
1003         public function isTalkPage() {
1004                 return MWNamespace::isTalk( $this->getNamespace() );
1005         }
1006
1007         /**
1008          * Get a Title object associated with the talk page of this article
1009          *
1010          * @return Title the object for the talk page
1011          */
1012         public function getTalkPage() {
1013                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1014         }
1015
1016         /**
1017          * Get a title object associated with the subject page of this
1018          * talk page
1019          *
1020          * @return Title the object for the subject page
1021          */
1022         public function getSubjectPage() {
1023                 // Is this the same title?
1024                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1025                 if ( $this->getNamespace() == $subjectNS ) {
1026                         return $this;
1027                 }
1028                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1029         }
1030
1031         /**
1032          * Get the default namespace index, for when there is no namespace
1033          *
1034          * @return Int Default namespace index
1035          */
1036         public function getDefaultNamespace() {
1037                 return $this->mDefaultNamespace;
1038         }
1039
1040         /**
1041          * Get title for search index
1042          *
1043          * @return String a stripped-down title string ready for the
1044          *  search index
1045          */
1046         public function getIndexTitle() {
1047                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1048         }
1049
1050         /**
1051          * Get the Title fragment (i.e.\ the bit after the #) in text form
1052          *
1053          * @return String Title fragment
1054          */
1055         public function getFragment() {
1056                 return $this->mFragment;
1057         }
1058
1059         /**
1060          * Get the fragment in URL form, including the "#" character if there is one
1061          * @return String Fragment in URL form
1062          */
1063         public function getFragmentForURL() {
1064                 if ( $this->mFragment == '' ) {
1065                         return '';
1066                 } else {
1067                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1068                 }
1069         }
1070
1071         /**
1072          * Set the fragment for this title. Removes the first character from the
1073          * specified fragment before setting, so it assumes you're passing it with
1074          * an initial "#".
1075          *
1076          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1077          * Still in active use privately.
1078          *
1079          * @param $fragment String text
1080          */
1081         public function setFragment( $fragment ) {
1082                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1083         }
1084
1085         /**
1086          * Prefix some arbitrary text with the namespace or interwiki prefix
1087          * of this object
1088          *
1089          * @param $name String the text
1090          * @return String the prefixed text
1091          * @private
1092          */
1093         private function prefix( $name ) {
1094                 $p = '';
1095                 if ( $this->mInterwiki != '' ) {
1096                         $p = $this->mInterwiki . ':';
1097                 }
1098
1099                 if ( 0 != $this->mNamespace ) {
1100                         $p .= $this->getNsText() . ':';
1101                 }
1102                 return $p . $name;
1103         }
1104
1105         /**
1106          * Get the prefixed database key form
1107          *
1108          * @return String the prefixed title, with underscores and
1109          *  any interwiki and namespace prefixes
1110          */
1111         public function getPrefixedDBkey() {
1112                 $s = $this->prefix( $this->mDbkeyform );
1113                 $s = str_replace( ' ', '_', $s );
1114                 return $s;
1115         }
1116
1117         /**
1118          * Get the prefixed title with spaces.
1119          * This is the form usually used for display
1120          *
1121          * @return String the prefixed title, with spaces
1122          */
1123         public function getPrefixedText() {
1124                 // @todo FIXME: Bad usage of empty() ?
1125                 if ( empty( $this->mPrefixedText ) ) {
1126                         $s = $this->prefix( $this->mTextform );
1127                         $s = str_replace( '_', ' ', $s );
1128                         $this->mPrefixedText = $s;
1129                 }
1130                 return $this->mPrefixedText;
1131         }
1132
1133         /**
1134          * Return a string representation of this title
1135          *
1136          * @return String representation of this title
1137          */
1138         public function __toString() {
1139                 return $this->getPrefixedText();
1140         }
1141
1142         /**
1143          * Get the prefixed title with spaces, plus any fragment
1144          * (part beginning with '#')
1145          *
1146          * @return String the prefixed title, with spaces and the fragment, including '#'
1147          */
1148         public function getFullText() {
1149                 $text = $this->getPrefixedText();
1150                 if ( $this->mFragment != '' ) {
1151                         $text .= '#' . $this->mFragment;
1152                 }
1153                 return $text;
1154         }
1155
1156         /**
1157          * Get the base page name, i.e. the leftmost part before any slashes
1158          *
1159          * @return String Base name
1160          */
1161         public function getBaseText() {
1162                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1163                         return $this->getText();
1164                 }
1165
1166                 $parts = explode( '/', $this->getText() );
1167                 # Don't discard the real title if there's no subpage involved
1168                 if ( count( $parts ) > 1 ) {
1169                         unset( $parts[count( $parts ) - 1] );
1170                 }
1171                 return implode( '/', $parts );
1172         }
1173
1174         /**
1175          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1176          *
1177          * @return String Subpage name
1178          */
1179         public function getSubpageText() {
1180                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1181                         return( $this->mTextform );
1182                 }
1183                 $parts = explode( '/', $this->mTextform );
1184                 return( $parts[count( $parts ) - 1] );
1185         }
1186
1187         /**
1188          * Get the HTML-escaped displayable text form.
1189          * Used for the title field in <a> tags.
1190          *
1191          * @return String the text, including any prefixes
1192          */
1193         public function getEscapedText() {
1194                 wfDeprecated( __METHOD__, '1.19' );
1195                 return htmlspecialchars( $this->getPrefixedText() );
1196         }
1197
1198         /**
1199          * Get a URL-encoded form of the subpage text
1200          *
1201          * @return String URL-encoded subpage name
1202          */
1203         public function getSubpageUrlForm() {
1204                 $text = $this->getSubpageText();
1205                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1206                 return( $text );
1207         }
1208
1209         /**
1210          * Get a URL-encoded title (not an actual URL) including interwiki
1211          *
1212          * @return String the URL-encoded form
1213          */
1214         public function getPrefixedURL() {
1215                 $s = $this->prefix( $this->mDbkeyform );
1216                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1217                 return $s;
1218         }
1219
1220         /**
1221          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1222          */
1223         private static function fixUrlQueryArgs( $query, $query2 ) {
1224                 if ( is_array( $query ) ) {
1225                         $query = wfArrayToCGI( $query );
1226                 }
1227                 if ( $query2 ) {
1228                         if ( is_string( $query2 ) ) {
1229                                 // $query2 is a string, we will consider this to be
1230                                 // a deprecated $variant argument and add it to the query
1231                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1232                         } else {
1233                                 $query2 = wfArrayToCGI( $query2 );
1234                         }
1235                         // If we have $query content add a & to it first
1236                         if ( $query ) {
1237                                 $query .= '&';
1238                         }
1239                         // Now append the queries together
1240                         $query .= $query2;
1241                 }
1242                 return $query;
1243         }
1244
1245         /**
1246          * Get a real URL referring to this title, with interwiki link and
1247          * fragment
1248          *
1249          * See getLocalURL for the arguments.
1250          *
1251          * @see self::getLocalURL
1252          * @return String the URL
1253          */
1254         public function getFullURL( $query = '', $query2 = false ) {
1255                 $query = self::fixUrlQueryArgs( $query, $query2 );
1256
1257                 # Hand off all the decisions on urls to getLocalURL
1258                 $url = $this->getLocalURL( $query );
1259
1260                 # Expand the url to make it a full url. Note that getLocalURL has the
1261                 # potential to output full urls for a variety of reasons, so we use
1262                 # wfExpandUrl instead of simply prepending $wgServer
1263                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1264
1265                 # Finally, add the fragment.
1266                 $url .= $this->getFragmentForURL();
1267
1268                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1269                 return $url;
1270         }
1271
1272         /**
1273          * Get a URL with no fragment or server name.  If this page is generated
1274          * with action=render, $wgServer is prepended.
1275          *
1276
1277          * @param $query \twotypes{\string,\array} an optional query string,
1278          *   not used for interwiki     links. Can be specified as an associative array as well,
1279          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1280          *   Some query patterns will trigger various shorturl path replacements.
1281          * @param $query2 Mixed: An optional secondary query array. This one MUST
1282          *   be an array. If a string is passed it will be interpreted as a deprecated
1283          *   variant argument and urlencoded into a variant= argument.
1284          *   This second query argument will be added to the $query
1285          * @return String the URL
1286          */
1287         public function getLocalURL( $query = '', $query2 = false ) {
1288                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1289
1290                 $query = self::fixUrlQueryArgs( $query, $query2 );
1291
1292                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1293                 if ( $interwiki ) {
1294                         $namespace = $this->getNsText();
1295                         if ( $namespace != '' ) {
1296                                 # Can this actually happen? Interwikis shouldn't be parsed.
1297                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1298                                 $namespace .= ':';
1299                         }
1300                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1301                         $url = wfAppendQuery( $url, $query );
1302                 } else {
1303                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1304                         if ( $query == '' ) {
1305                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1306                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1307                         } else {
1308                                 global $wgVariantArticlePath, $wgActionPaths;
1309                                 $url = false;
1310                                 $matches = array();
1311
1312                                 if ( !empty( $wgActionPaths ) &&
1313                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1314                                 {
1315                                         $action = urldecode( $matches[2] );
1316                                         if ( isset( $wgActionPaths[$action] ) ) {
1317                                                 $query = $matches[1];
1318                                                 if ( isset( $matches[4] ) ) {
1319                                                         $query .= $matches[4];
1320                                                 }
1321                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1322                                                 if ( $query != '' ) {
1323                                                         $url = wfAppendQuery( $url, $query );
1324                                                 }
1325                                         }
1326                                 }
1327
1328                                 if ( $url === false &&
1329                                         $wgVariantArticlePath &&
1330                                         $this->getPageLanguage()->hasVariants() &&
1331                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1332                                 {
1333                                         $variant = urldecode( $matches[1] );
1334                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1335                                                 // Only do the variant replacement if the given variant is a valid
1336                                                 // variant for the page's language.
1337                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1338                                                 $url = str_replace( '$1', $dbkey, $url );
1339                                         }
1340                                 }
1341
1342                                 if ( $url === false ) {
1343                                         if ( $query == '-' ) {
1344                                                 $query = '';
1345                                         }
1346                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1347                                 }
1348                         }
1349
1350                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1351
1352                         // @todo FIXME: This causes breakage in various places when we
1353                         // actually expected a local URL and end up with dupe prefixes.
1354                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1355                                 $url = $wgServer . $url;
1356                         }
1357                 }
1358                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1359                 return $url;
1360         }
1361
1362         /**
1363          * Get a URL that's the simplest URL that will be valid to link, locally,
1364          * to the current Title.  It includes the fragment, but does not include
1365          * the server unless action=render is used (or the link is external).  If
1366          * there's a fragment but the prefixed text is empty, we just return a link
1367          * to the fragment.
1368          *
1369          * The result obviously should not be URL-escaped, but does need to be
1370          * HTML-escaped if it's being output in HTML.
1371          *
1372          * See getLocalURL for the arguments.
1373          *
1374          * @see self::getLocalURL
1375          * @return String the URL
1376          */
1377         public function getLinkURL( $query = '', $query2 = false ) {
1378                 wfProfileIn( __METHOD__ );
1379                 if ( $this->isExternal() ) {
1380                         $ret = $this->getFullURL( $query, $query2 );
1381                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1382                         $ret = $this->getFragmentForURL();
1383                 } else {
1384                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1385                 }
1386                 wfProfileOut( __METHOD__ );
1387                 return $ret;
1388         }
1389
1390         /**
1391          * Get an HTML-escaped version of the URL form, suitable for
1392          * using in a link, without a server name or fragment
1393          *
1394          * See getLocalURL for the arguments.
1395          *
1396          * @see self::getLocalURL
1397          * @return String the URL
1398          */
1399         public function escapeLocalURL( $query = '', $query2 = false ) {
1400                 wfDeprecated( __METHOD__, '1.19' );
1401                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1402         }
1403
1404         /**
1405          * Get an HTML-escaped version of the URL form, suitable for
1406          * using in a link, including the server name and fragment
1407          *
1408          * See getLocalURL for the arguments.
1409          *
1410          * @see self::getLocalURL
1411          * @return String the URL
1412          */
1413         public function escapeFullURL( $query = '', $query2 = false ) {
1414                 wfDeprecated( __METHOD__, '1.19' );
1415                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1416         }
1417
1418         /**
1419          * Get the URL form for an internal link.
1420          * - Used in various Squid-related code, in case we have a different
1421          * internal hostname for the server from the exposed one.
1422          *
1423          * This uses $wgInternalServer to qualify the path, or $wgServer
1424          * if $wgInternalServer is not set. If the server variable used is
1425          * protocol-relative, the URL will be expanded to http://
1426          *
1427          * See getLocalURL for the arguments.
1428          *
1429          * @see self::getLocalURL
1430          * @return String the URL
1431          */
1432         public function getInternalURL( $query = '', $query2 = false ) {
1433                 global $wgInternalServer, $wgServer;
1434                 $query = self::fixUrlQueryArgs( $query, $query2 );
1435                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1436                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1437                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1438                 return $url;
1439         }
1440
1441         /**
1442          * Get the URL for a canonical link, for use in things like IRC and
1443          * e-mail notifications. Uses $wgCanonicalServer and the
1444          * GetCanonicalURL hook.
1445          *
1446          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1447          *
1448          * See getLocalURL for the arguments.
1449          *
1450          * @see self::getLocalURL
1451          * @return string The URL
1452          * @since 1.18
1453          */
1454         public function getCanonicalURL( $query = '', $query2 = false ) {
1455                 $query = self::fixUrlQueryArgs( $query, $query2 );
1456                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1457                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1458                 return $url;
1459         }
1460
1461         /**
1462          * HTML-escaped version of getCanonicalURL()
1463          *
1464          * See getLocalURL for the arguments.
1465          *
1466          * @see self::getLocalURL
1467          * @since 1.18
1468          */
1469         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1470                 wfDeprecated( __METHOD__, '1.19' );
1471                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1472         }
1473
1474         /**
1475          * Get the edit URL for this Title
1476          *
1477          * @return String the URL, or a null string if this is an
1478          *  interwiki link
1479          */
1480         public function getEditURL() {
1481                 if ( $this->mInterwiki != '' ) {
1482                         return '';
1483                 }
1484                 $s = $this->getLocalURL( 'action=edit' );
1485
1486                 return $s;
1487         }
1488
1489         /**
1490          * Is $wgUser watching this page?
1491          *
1492          * @return Bool
1493          */
1494         public function userIsWatching() {
1495                 global $wgUser;
1496
1497                 if ( is_null( $this->mWatched ) ) {
1498                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1499                                 $this->mWatched = false;
1500                         } else {
1501                                 $this->mWatched = $wgUser->isWatched( $this );
1502                         }
1503                 }
1504                 return $this->mWatched;
1505         }
1506
1507         /**
1508          * Can $wgUser read this page?
1509          *
1510          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1511          * @return Bool
1512          * @todo fold these checks into userCan()
1513          */
1514         public function userCanRead() {
1515                 wfDeprecated( __METHOD__, '1.19' );
1516                 return $this->userCan( 'read' );
1517         }
1518
1519         /**
1520          * Can $user perform $action on this page?
1521          * This skips potentially expensive cascading permission checks
1522          * as well as avoids expensive error formatting
1523          *
1524          * Suitable for use for nonessential UI controls in common cases, but
1525          * _not_ for functional access control.
1526          *
1527          * May provide false positives, but should never provide a false negative.
1528          *
1529          * @param $action String action that permission needs to be checked for
1530          * @param $user User to check (since 1.19); $wgUser will be used if not
1531          *              provided.
1532          * @return Bool
1533          */
1534         public function quickUserCan( $action, $user = null ) {
1535                 return $this->userCan( $action, $user, false );
1536         }
1537
1538         /**
1539          * Can $user perform $action on this page?
1540          *
1541          * @param $action String action that permission needs to be checked for
1542          * @param $user User to check (since 1.19); $wgUser will be used if not
1543          *   provided.
1544          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1545          *   unnecessary queries.
1546          * @return Bool
1547          */
1548         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1549                 if ( !$user instanceof User ) {
1550                         global $wgUser;
1551                         $user = $wgUser;
1552                 }
1553                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1554         }
1555
1556         /**
1557          * Can $user perform $action on this page?
1558          *
1559          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1560          *
1561          * @param $action String action that permission needs to be checked for
1562          * @param $user User to check
1563          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1564          *   queries by skipping checks for cascading protections and user blocks.
1565          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1566          *   whose corresponding errors may be ignored.
1567          * @return Array of arguments to wfMsg to explain permissions problems.
1568          */
1569         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1570                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1571
1572                 // Remove the errors being ignored.
1573                 foreach ( $errors as $index => $error ) {
1574                         $error_key = is_array( $error ) ? $error[0] : $error;
1575
1576                         if ( in_array( $error_key, $ignoreErrors ) ) {
1577                                 unset( $errors[$index] );
1578                         }
1579                 }
1580
1581                 return $errors;
1582         }
1583
1584         /**
1585          * Permissions checks that fail most often, and which are easiest to test.
1586          *
1587          * @param $action String the action to check
1588          * @param $user User user to check
1589          * @param $errors Array list of current errors
1590          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1591          * @param $short Boolean short circuit on first error
1592          *
1593          * @return Array list of errors
1594          */
1595         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1596                 if ( $action == 'create' ) {
1597                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1598                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1599                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1600                         }
1601                 } elseif ( $action == 'move' ) {
1602                         if ( !$user->isAllowed( 'move-rootuserpages' )
1603                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1604                                 // Show user page-specific message only if the user can move other pages
1605                                 $errors[] = array( 'cant-move-user-page' );
1606                         }
1607
1608                         // Check if user is allowed to move files if it's a file
1609                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1610                                 $errors[] = array( 'movenotallowedfile' );
1611                         }
1612
1613                         if ( !$user->isAllowed( 'move' ) ) {
1614                                 // User can't move anything
1615                                 global $wgGroupPermissions;
1616                                 $userCanMove = false;
1617                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1618                                         $userCanMove = $wgGroupPermissions['user']['move'];
1619                                 }
1620                                 $autoconfirmedCanMove = false;
1621                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1622                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1623                                 }
1624                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1625                                         // custom message if logged-in users without any special rights can move
1626                                         $errors[] = array( 'movenologintext' );
1627                                 } else {
1628                                         $errors[] = array( 'movenotallowed' );
1629                                 }
1630                         }
1631                 } elseif ( $action == 'move-target' ) {
1632                         if ( !$user->isAllowed( 'move' ) ) {
1633                                 // User can't move anything
1634                                 $errors[] = array( 'movenotallowed' );
1635                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1636                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1637                                 // Show user page-specific message only if the user can move other pages
1638                                 $errors[] = array( 'cant-move-to-user-page' );
1639                         }
1640                 } elseif ( !$user->isAllowed( $action ) ) {
1641                         $errors[] = $this->missingPermissionError( $action, $short );
1642                 }
1643
1644                 return $errors;
1645         }
1646
1647         /**
1648          * Add the resulting error code to the errors array
1649          *
1650          * @param $errors Array list of current errors
1651          * @param $result Mixed result of errors
1652          *
1653          * @return Array list of errors
1654          */
1655         private function resultToError( $errors, $result ) {
1656                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1657                         // A single array representing an error
1658                         $errors[] = $result;
1659                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1660                         // A nested array representing multiple errors
1661                         $errors = array_merge( $errors, $result );
1662                 } elseif ( $result !== '' && is_string( $result ) ) {
1663                         // A string representing a message-id
1664                         $errors[] = array( $result );
1665                 } elseif ( $result === false ) {
1666                         // a generic "We don't want them to do that"
1667                         $errors[] = array( 'badaccess-group0' );
1668                 }
1669                 return $errors;
1670         }
1671
1672         /**
1673          * Check various permission hooks
1674          *
1675          * @param $action String the action to check
1676          * @param $user User user to check
1677          * @param $errors Array list of current errors
1678          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1679          * @param $short Boolean short circuit on first error
1680          *
1681          * @return Array list of errors
1682          */
1683         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1684                 // Use getUserPermissionsErrors instead
1685                 $result = '';
1686                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1687                         return $result ? array() : array( array( 'badaccess-group0' ) );
1688                 }
1689                 // Check getUserPermissionsErrors hook
1690                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1691                         $errors = $this->resultToError( $errors, $result );
1692                 }
1693                 // Check getUserPermissionsErrorsExpensive hook
1694                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1695                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1696                         $errors = $this->resultToError( $errors, $result );
1697                 }
1698
1699                 return $errors;
1700         }
1701
1702         /**
1703          * Check permissions on special pages & namespaces
1704          *
1705          * @param $action String the action to check
1706          * @param $user User user to check
1707          * @param $errors Array list of current errors
1708          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1709          * @param $short Boolean short circuit on first error
1710          *
1711          * @return Array list of errors
1712          */
1713         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1714                 # Only 'createaccount' and 'execute' can be performed on
1715                 # special pages, which don't actually exist in the DB.
1716                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1717                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1718                         $errors[] = array( 'ns-specialprotected' );
1719                 }
1720
1721                 # Check $wgNamespaceProtection for restricted namespaces
1722                 if ( $this->isNamespaceProtected( $user ) ) {
1723                         $ns = $this->mNamespace == NS_MAIN ?
1724                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1725                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1726                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1727                 }
1728
1729                 return $errors;
1730         }
1731
1732         /**
1733          * Check CSS/JS sub-page permissions
1734          *
1735          * @param $action String the action to check
1736          * @param $user User user to check
1737          * @param $errors Array list of current errors
1738          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1739          * @param $short Boolean short circuit on first error
1740          *
1741          * @return Array list of errors
1742          */
1743         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1744                 # Protect css/js subpages of user pages
1745                 # XXX: this might be better using restrictions
1746                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1747                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1748                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1749                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1750                                 $errors[] = array( 'customcssprotected' );
1751                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1752                                 $errors[] = array( 'customjsprotected' );
1753                         }
1754                 }
1755
1756                 return $errors;
1757         }
1758
1759         /**
1760          * Check against page_restrictions table requirements on this
1761          * page. The user must possess all required rights for this
1762          * action.
1763          *
1764          * @param $action String the action to check
1765          * @param $user User user to check
1766          * @param $errors Array list of current errors
1767          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1768          * @param $short Boolean short circuit on first error
1769          *
1770          * @return Array list of errors
1771          */
1772         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1773                 foreach ( $this->getRestrictions( $action ) as $right ) {
1774                         // Backwards compatibility, rewrite sysop -> protect
1775                         if ( $right == 'sysop' ) {
1776                                 $right = 'protect';
1777                         }
1778                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1779                                 // Users with 'editprotected' permission can edit protected pages
1780                                 // without cascading option turned on.
1781                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1782                                         || $this->mCascadeRestriction )
1783                                 {
1784                                         $errors[] = array( 'protectedpagetext', $right );
1785                                 }
1786                         }
1787                 }
1788
1789                 return $errors;
1790         }
1791
1792         /**
1793          * Check restrictions on cascading pages.
1794          *
1795          * @param $action String the action to check
1796          * @param $user User to check
1797          * @param $errors Array list of current errors
1798          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1799          * @param $short Boolean short circuit on first error
1800          *
1801          * @return Array list of errors
1802          */
1803         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1804                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1805                         # We /could/ use the protection level on the source page, but it's
1806                         # fairly ugly as we have to establish a precedence hierarchy for pages
1807                         # included by multiple cascade-protected pages. So just restrict
1808                         # it to people with 'protect' permission, as they could remove the
1809                         # protection anyway.
1810                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1811                         # Cascading protection depends on more than this page...
1812                         # Several cascading protected pages may include this page...
1813                         # Check each cascading level
1814                         # This is only for protection restrictions, not for all actions
1815                         if ( isset( $restrictions[$action] ) ) {
1816                                 foreach ( $restrictions[$action] as $right ) {
1817                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1818                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1819                                                 $pages = '';
1820                                                 foreach ( $cascadingSources as $page )
1821                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1822                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1823                                         }
1824                                 }
1825                         }
1826                 }
1827
1828                 return $errors;
1829         }
1830
1831         /**
1832          * Check action permissions not already checked in checkQuickPermissions
1833          *
1834          * @param $action String the action to check
1835          * @param $user User to check
1836          * @param $errors Array list of current errors
1837          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1838          * @param $short Boolean short circuit on first error
1839          *
1840          * @return Array list of errors
1841          */
1842         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1843                 global $wgDeleteRevisionsLimit, $wgLang;
1844
1845                 if ( $action == 'protect' ) {
1846                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1847                                 // If they can't edit, they shouldn't protect.
1848                                 $errors[] = array( 'protect-cantedit' );
1849                         }
1850                 } elseif ( $action == 'create' ) {
1851                         $title_protection = $this->getTitleProtection();
1852                         if( $title_protection ) {
1853                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1854                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1855                                 }
1856                                 if( $title_protection['pt_create_perm'] == '' ||
1857                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1858                                 {
1859                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1860                                 }
1861                         }
1862                 } elseif ( $action == 'move' ) {
1863                         // Check for immobile pages
1864                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1865                                 // Specific message for this case
1866                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1867                         } elseif ( !$this->isMovable() ) {
1868                                 // Less specific message for rarer cases
1869                                 $errors[] = array( 'immobile-source-page' );
1870                         }
1871                 } elseif ( $action == 'move-target' ) {
1872                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1873                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1874                         } elseif ( !$this->isMovable() ) {
1875                                 $errors[] = array( 'immobile-target-page' );
1876                         }
1877                 } elseif ( $action == 'delete' ) {
1878                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1879                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1880                         {
1881                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1882                         }
1883                 }
1884                 return $errors;
1885         }
1886
1887         /**
1888          * Check that the user isn't blocked from editting.
1889          *
1890          * @param $action String the action to check
1891          * @param $user User to check
1892          * @param $errors Array list of current errors
1893          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1894          * @param $short Boolean short circuit on first error
1895          *
1896          * @return Array list of errors
1897          */
1898         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1899                 // Account creation blocks handled at userlogin.
1900                 // Unblocking handled in SpecialUnblock
1901                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1902                         return $errors;
1903                 }
1904
1905                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1906
1907                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1908                         $errors[] = array( 'confirmedittext' );
1909                 }
1910
1911                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1912                         // Don't block the user from editing their own talk page unless they've been
1913                         // explicitly blocked from that too.
1914                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1915                         $block = $user->mBlock;
1916
1917                         // This is from OutputPage::blockedPage
1918                         // Copied at r23888 by werdna
1919
1920                         $id = $user->blockedBy();
1921                         $reason = $user->blockedFor();
1922                         if ( $reason == '' ) {
1923                                 $reason = wfMsg( 'blockednoreason' );
1924                         }
1925                         $ip = $user->getRequest()->getIP();
1926
1927                         if ( is_numeric( $id ) ) {
1928                                 $name = User::whoIs( $id );
1929                         } else {
1930                                 $name = $id;
1931                         }
1932
1933                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1934                         $blockid = $block->getId();
1935                         $blockExpiry = $user->mBlock->mExpiry;
1936                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1937                         if ( $blockExpiry == 'infinity' ) {
1938                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1939                         } else {
1940                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1941                         }
1942
1943                         $intended = strval( $user->mBlock->getTarget() );
1944
1945                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1946                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1947                 }
1948
1949                 return $errors;
1950         }
1951
1952         /**
1953          * Check that the user is allowed to read this page.
1954          *
1955          * @param $action String the action to check
1956          * @param $user User to check
1957          * @param $errors Array list of current errors
1958          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1959          * @param $short Boolean short circuit on first error
1960          *
1961          * @return Array list of errors
1962          */
1963         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1964                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
1965                 static $useShortcut = null;
1966
1967                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1968                 if ( is_null( $useShortcut ) ) {
1969                         $useShortcut = true;
1970                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1971                                 # Not a public wiki, so no shortcut
1972                                 $useShortcut = false;
1973                         } elseif ( !empty( $wgRevokePermissions ) ) {
1974                                 /**
1975                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1976                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1977                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1978                                  * reading is allowed.
1979                                  */
1980                                 foreach ( $wgRevokePermissions as $perms ) {
1981                                         if ( !empty( $perms['read'] ) ) {
1982                                                 # We might be removing the read right from the user, so no shortcut
1983                                                 $useShortcut = false;
1984                                                 break;
1985                                         }
1986                                 }
1987                         }
1988                 }
1989
1990                 $whitelisted = false;
1991                 if ( $useShortcut ) {
1992                         # Shortcut for public wikis, allows skipping quite a bit of code
1993                         $whitelisted = true;
1994                 } elseif ( $user->isAllowed( 'read' ) ) {
1995                         # If the user is allowed to read pages, he is allowed to read all pages
1996                         $whitelisted = true;
1997                 } elseif ( $this->isSpecial( 'Userlogin' )
1998                         || $this->isSpecial( 'ChangePassword' )
1999                         || $this->isSpecial( 'PasswordReset' )
2000                 ) {
2001                         # Always grant access to the login page.
2002                         # Even anons need to be able to log in.
2003                         $whitelisted = true;
2004                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2005                         # Time to check the whitelist
2006                         # Only do these checks is there's something to check against
2007                         $name = $this->getPrefixedText();
2008                         $dbName = $this->getPrefixedDBKey();
2009
2010                         // Check with and without underscores
2011                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2012                                 # Check for explicit whitelisting
2013                                 $whitelisted = true;
2014                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2015                                 # Old settings might have the title prefixed with
2016                                 # a colon for main-namespace pages
2017                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2018                                         $whitelisted = true;
2019                                 }
2020                         } elseif ( $this->isSpecialPage() ) {
2021                                 # If it's a special page, ditch the subpage bit and check again
2022                                 $name = $this->getDBkey();
2023                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2024                                 if ( $name !== false ) {
2025                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2026                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2027                                                 $whitelisted = true;
2028                                         }
2029                                 }
2030                         }
2031                 }
2032
2033                 if ( !$whitelisted ) {
2034                         # If the title is not whitelisted, give extensions a chance to do so...
2035                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2036                         if ( !$whitelisted ) {
2037                                 $errors[] = $this->missingPermissionError( $action, $short );
2038                         }
2039                 }
2040
2041                 return $errors;
2042         }
2043
2044         /**
2045          * Get a description array when the user doesn't have the right to perform
2046          * $action (i.e. when User::isAllowed() returns false)
2047          *
2048          * @param $action String the action to check
2049          * @param $short Boolean short circuit on first error
2050          * @return Array list of errors
2051          */
2052         private function missingPermissionError( $action, $short ) {
2053                 // We avoid expensive display logic for quickUserCan's and such
2054                 if ( $short ) {
2055                         return array( 'badaccess-group0' );
2056                 }
2057
2058                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2059                         User::getGroupsWithPermission( $action ) );
2060
2061                 if ( count( $groups ) ) {
2062                         global $wgLang;
2063                         return array(
2064                                 'badaccess-groups',
2065                                 $wgLang->commaList( $groups ),
2066                                 count( $groups )
2067                         );
2068                 } else {
2069                         return array( 'badaccess-group0' );
2070                 }
2071         }
2072
2073         /**
2074          * Can $user perform $action on this page? This is an internal function,
2075          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2076          * checks on wfReadOnly() and blocks)
2077          *
2078          * @param $action String action that permission needs to be checked for
2079          * @param $user User to check
2080          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2081          * @param $short Bool Set this to true to stop after the first permission error.
2082          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2083          */
2084         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2085                 wfProfileIn( __METHOD__ );
2086
2087                 # Read has special handling
2088                 if ( $action == 'read' ) {
2089                         $checks = array(
2090                                 'checkPermissionHooks',
2091                                 'checkReadPermissions',
2092                         );
2093                 } else {
2094                         $checks = array(
2095                                 'checkQuickPermissions',
2096                                 'checkPermissionHooks',
2097                                 'checkSpecialsAndNSPermissions',
2098                                 'checkCSSandJSPermissions',
2099                                 'checkPageRestrictions',
2100                                 'checkCascadingSourcesRestrictions',
2101                                 'checkActionPermissions',
2102                                 'checkUserBlock'
2103                         );
2104                 }
2105
2106                 $errors = array();
2107                 while( count( $checks ) > 0 &&
2108                                 !( $short && count( $errors ) > 0 ) ) {
2109                         $method = array_shift( $checks );
2110                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2111                 }
2112
2113                 wfProfileOut( __METHOD__ );
2114                 return $errors;
2115         }
2116
2117         /**
2118          * Protect css subpages of user pages: can $wgUser edit
2119          * this page?
2120          *
2121          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2122          * @return Bool
2123          */
2124         public function userCanEditCssSubpage() {
2125                 global $wgUser;
2126                 wfDeprecated( __METHOD__, '1.19' );
2127                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2128                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2129         }
2130
2131         /**
2132          * Protect js subpages of user pages: can $wgUser edit
2133          * this page?
2134          *
2135          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2136          * @return Bool
2137          */
2138         public function userCanEditJsSubpage() {
2139                 global $wgUser;
2140                 wfDeprecated( __METHOD__, '1.19' );
2141                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2142                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2143         }
2144
2145         /**
2146          * Get a filtered list of all restriction types supported by this wiki.
2147          * @param bool $exists True to get all restriction types that apply to
2148          * titles that do exist, False for all restriction types that apply to
2149          * titles that do not exist
2150          * @return array
2151          */
2152         public static function getFilteredRestrictionTypes( $exists = true ) {
2153                 global $wgRestrictionTypes;
2154                 $types = $wgRestrictionTypes;
2155                 if ( $exists ) {
2156                         # Remove the create restriction for existing titles
2157                         $types = array_diff( $types, array( 'create' ) );
2158                 } else {
2159                         # Only the create and upload restrictions apply to non-existing titles
2160                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2161                 }
2162                 return $types;
2163         }
2164
2165         /**
2166          * Returns restriction types for the current Title
2167          *
2168          * @return array applicable restriction types
2169          */
2170         public function getRestrictionTypes() {
2171                 if ( $this->isSpecialPage() ) {
2172                         return array();
2173                 }
2174
2175                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2176
2177                 if ( $this->getNamespace() != NS_FILE ) {
2178                         # Remove the upload restriction for non-file titles
2179                         $types = array_diff( $types, array( 'upload' ) );
2180                 }
2181
2182                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2183
2184                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2185                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2186
2187                 return $types;
2188         }
2189
2190         /**
2191          * Is this title subject to title protection?
2192          * Title protection is the one applied against creation of such title.
2193          *
2194          * @return Mixed An associative array representing any existent title
2195          *   protection, or false if there's none.
2196          */
2197         private function getTitleProtection() {
2198                 // Can't protect pages in special namespaces
2199                 if ( $this->getNamespace() < 0 ) {
2200                         return false;
2201                 }
2202
2203                 // Can't protect pages that exist.
2204                 if ( $this->exists() ) {
2205                         return false;
2206                 }
2207
2208                 if ( !isset( $this->mTitleProtection ) ) {
2209                         $dbr = wfGetDB( DB_SLAVE );
2210                         $res = $dbr->select( 'protected_titles', '*',
2211                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2212                                 __METHOD__ );
2213
2214                         // fetchRow returns false if there are no rows.
2215                         $this->mTitleProtection = $dbr->fetchRow( $res );
2216                 }
2217                 return $this->mTitleProtection;
2218         }
2219
2220         /**
2221          * Update the title protection status
2222          *
2223          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2224          * @param $create_perm String Permission required for creation
2225          * @param $reason String Reason for protection
2226          * @param $expiry String Expiry timestamp
2227          * @return boolean true
2228          */
2229         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2230                 wfDeprecated( __METHOD__, '1.19' );
2231
2232                 global $wgUser;
2233
2234                 $limit = array( 'create' => $create_perm );
2235                 $expiry = array( 'create' => $expiry );
2236
2237                 $page = WikiPage::factory( $this );
2238                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2239
2240                 return $status->isOK();
2241         }
2242
2243         /**
2244          * Remove any title protection due to page existing
2245          */
2246         public function deleteTitleProtection() {
2247                 $dbw = wfGetDB( DB_MASTER );
2248
2249                 $dbw->delete(
2250                         'protected_titles',
2251                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2252                         __METHOD__
2253                 );
2254                 $this->mTitleProtection = false;
2255         }
2256
2257         /**
2258          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2259          *
2260          * @param $action String Action to check (default: edit)
2261          * @return Bool
2262          */
2263         public function isSemiProtected( $action = 'edit' ) {
2264                 if ( $this->exists() ) {
2265                         $restrictions = $this->getRestrictions( $action );
2266                         if ( count( $restrictions ) > 0 ) {
2267                                 foreach ( $restrictions as $restriction ) {
2268                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2269                                                 return false;
2270                                         }
2271                                 }
2272                         } else {
2273                                 # Not protected
2274                                 return false;
2275                         }
2276                         return true;
2277                 } else {
2278                         # If it doesn't exist, it can't be protected
2279                         return false;
2280                 }
2281         }
2282
2283         /**
2284          * Does the title correspond to a protected article?
2285          *
2286          * @param $action String the action the page is protected from,
2287          * by default checks all actions.
2288          * @return Bool
2289          */
2290         public function isProtected( $action = '' ) {
2291                 global $wgRestrictionLevels;
2292
2293                 $restrictionTypes = $this->getRestrictionTypes();
2294
2295                 # Special pages have inherent protection
2296                 if( $this->isSpecialPage() ) {
2297                         return true;
2298                 }
2299
2300                 # Check regular protection levels
2301                 foreach ( $restrictionTypes as $type ) {
2302                         if ( $action == $type || $action == '' ) {
2303                                 $r = $this->getRestrictions( $type );
2304                                 foreach ( $wgRestrictionLevels as $level ) {
2305                                         if ( in_array( $level, $r ) && $level != '' ) {
2306                                                 return true;
2307                                         }
2308                                 }
2309                         }
2310                 }
2311
2312                 return false;
2313         }
2314
2315         /**
2316          * Determines if $user is unable to edit this page because it has been protected
2317          * by $wgNamespaceProtection.
2318          *
2319          * @param $user User object to check permissions
2320          * @return Bool
2321          */
2322         public function isNamespaceProtected( User $user ) {
2323                 global $wgNamespaceProtection;
2324
2325                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2326                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2327                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2328                                         return true;
2329                                 }
2330                         }
2331                 }
2332                 return false;
2333         }
2334
2335         /**
2336          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2337          *
2338          * @return Bool If the page is subject to cascading restrictions.
2339          */
2340         public function isCascadeProtected() {
2341                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2342                 return ( $sources > 0 );
2343         }
2344
2345         /**
2346          * Cascading protection: Get the source of any cascading restrictions on this page.
2347          *
2348          * @param $getPages Bool Whether or not to retrieve the actual pages
2349          *        that the restrictions have come from.
2350          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2351          *     have come, false for none, or true if such restrictions exist, but $getPages
2352          *     was not set.  The restriction array is an array of each type, each of which
2353          *     contains a array of unique groups.
2354          */
2355         public function getCascadeProtectionSources( $getPages = true ) {
2356                 global $wgContLang;
2357                 $pagerestrictions = array();
2358
2359                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2360                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2361                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2362                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2363                 }
2364
2365                 wfProfileIn( __METHOD__ );
2366
2367                 $dbr = wfGetDB( DB_SLAVE );
2368
2369                 if ( $this->getNamespace() == NS_FILE ) {
2370                         $tables = array( 'imagelinks', 'page_restrictions' );
2371                         $where_clauses = array(
2372                                 'il_to' => $this->getDBkey(),
2373                                 'il_from=pr_page',
2374                                 'pr_cascade' => 1
2375                         );
2376                 } else {
2377                         $tables = array( 'templatelinks', 'page_restrictions' );
2378                         $where_clauses = array(
2379                                 'tl_namespace' => $this->getNamespace(),
2380                                 'tl_title' => $this->getDBkey(),
2381                                 'tl_from=pr_page',
2382                                 'pr_cascade' => 1
2383                         );
2384                 }
2385
2386                 if ( $getPages ) {
2387                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2388                                                    'pr_expiry', 'pr_type', 'pr_level' );
2389                         $where_clauses[] = 'page_id=pr_page';
2390                         $tables[] = 'page';
2391                 } else {
2392                         $cols = array( 'pr_expiry' );
2393                 }
2394
2395                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2396
2397                 $sources = $getPages ? array() : false;
2398                 $now = wfTimestampNow();
2399                 $purgeExpired = false;
2400
2401                 foreach ( $res as $row ) {
2402                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2403                         if ( $expiry > $now ) {
2404                                 if ( $getPages ) {
2405                                         $page_id = $row->pr_page;
2406                                         $page_ns = $row->page_namespace;
2407                                         $page_title = $row->page_title;
2408                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2409                                         # Add groups needed for each restriction type if its not already there
2410                                         # Make sure this restriction type still exists
2411
2412                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2413                                                 $pagerestrictions[$row->pr_type] = array();
2414                                         }
2415
2416                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2417                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2418                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2419                                         }
2420                                 } else {
2421                                         $sources = true;
2422                                 }
2423                         } else {
2424                                 // Trigger lazy purge of expired restrictions from the db
2425                                 $purgeExpired = true;
2426                         }
2427                 }
2428                 if ( $purgeExpired ) {
2429                         Title::purgeExpiredRestrictions();
2430                 }
2431
2432                 if ( $getPages ) {
2433                         $this->mCascadeSources = $sources;
2434                         $this->mCascadingRestrictions = $pagerestrictions;
2435                 } else {
2436                         $this->mHasCascadingRestrictions = $sources;
2437                 }
2438
2439                 wfProfileOut( __METHOD__ );
2440                 return array( $sources, $pagerestrictions );
2441         }
2442
2443         /**
2444          * Accessor/initialisation for mRestrictions
2445          *
2446          * @param $action String action that permission needs to be checked for
2447          * @return Array of Strings the array of groups allowed to edit this article
2448          */
2449         public function getRestrictions( $action ) {
2450                 if ( !$this->mRestrictionsLoaded ) {
2451                         $this->loadRestrictions();
2452                 }
2453                 return isset( $this->mRestrictions[$action] )
2454                                 ? $this->mRestrictions[$action]
2455                                 : array();
2456         }
2457
2458         /**
2459          * Get the expiry time for the restriction against a given action
2460          *
2461          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2462          *      or not protected at all, or false if the action is not recognised.
2463          */
2464         public function getRestrictionExpiry( $action ) {
2465                 if ( !$this->mRestrictionsLoaded ) {
2466                         $this->loadRestrictions();
2467                 }
2468                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2469         }
2470
2471         /**
2472          * Returns cascading restrictions for the current article
2473          *
2474          * @return Boolean
2475          */
2476         function areRestrictionsCascading() {
2477                 if ( !$this->mRestrictionsLoaded ) {
2478                         $this->loadRestrictions();
2479                 }
2480
2481                 return $this->mCascadeRestriction;
2482         }
2483
2484         /**
2485          * Loads a string into mRestrictions array
2486          *
2487          * @param $res Resource restrictions as an SQL result.
2488          * @param $oldFashionedRestrictions String comma-separated list of page
2489          *        restrictions from page table (pre 1.10)
2490          */
2491         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2492                 $rows = array();
2493
2494                 foreach ( $res as $row ) {
2495                         $rows[] = $row;
2496                 }
2497
2498                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2499         }
2500
2501         /**
2502          * Compiles list of active page restrictions from both page table (pre 1.10)
2503          * and page_restrictions table for this existing page.
2504          * Public for usage by LiquidThreads.
2505          *
2506          * @param $rows array of db result objects
2507          * @param $oldFashionedRestrictions string comma-separated list of page
2508          *        restrictions from page table (pre 1.10)
2509          */
2510         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2511                 global $wgContLang;
2512                 $dbr = wfGetDB( DB_SLAVE );
2513
2514                 $restrictionTypes = $this->getRestrictionTypes();
2515
2516                 foreach ( $restrictionTypes as $type ) {
2517                         $this->mRestrictions[$type] = array();
2518                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2519                 }
2520
2521                 $this->mCascadeRestriction = false;
2522
2523                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2524
2525                 if ( $oldFashionedRestrictions === null ) {
2526                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2527                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2528                 }
2529
2530                 if ( $oldFashionedRestrictions != '' ) {
2531
2532                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2533                                 $temp = explode( '=', trim( $restrict ) );
2534                                 if ( count( $temp ) == 1 ) {
2535                                         // old old format should be treated as edit/move restriction
2536                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2537                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2538                                 } else {
2539                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2540                                 }
2541                         }
2542
2543                         $this->mOldRestrictions = true;
2544
2545                 }
2546
2547                 if ( count( $rows ) ) {
2548                         # Current system - load second to make them override.
2549                         $now = wfTimestampNow();
2550                         $purgeExpired = false;
2551
2552                         # Cycle through all the restrictions.
2553                         foreach ( $rows as $row ) {
2554
2555                                 // Don't take care of restrictions types that aren't allowed
2556                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2557                                         continue;
2558
2559                                 // This code should be refactored, now that it's being used more generally,
2560                                 // But I don't really see any harm in leaving it in Block for now -werdna
2561                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2562
2563                                 // Only apply the restrictions if they haven't expired!
2564                                 if ( !$expiry || $expiry > $now ) {
2565                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2566                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2567
2568                                         $this->mCascadeRestriction |= $row->pr_cascade;
2569                                 } else {
2570                                         // Trigger a lazy purge of expired restrictions
2571                                         $purgeExpired = true;
2572                                 }
2573                         }
2574
2575                         if ( $purgeExpired ) {
2576                                 Title::purgeExpiredRestrictions();
2577                         }
2578                 }
2579
2580                 $this->mRestrictionsLoaded = true;
2581         }
2582
2583         /**
2584          * Load restrictions from the page_restrictions table
2585          *
2586          * @param $oldFashionedRestrictions String comma-separated list of page
2587          *        restrictions from page table (pre 1.10)
2588          */
2589         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2590                 global $wgContLang;
2591                 if ( !$this->mRestrictionsLoaded ) {
2592                         if ( $this->exists() ) {
2593                                 $dbr = wfGetDB( DB_SLAVE );
2594
2595                                 $res = $dbr->select(
2596                                         'page_restrictions',
2597                                         '*',
2598                                         array( 'pr_page' => $this->getArticleId() ),
2599                                         __METHOD__
2600                                 );
2601
2602                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2603                         } else {
2604                                 $title_protection = $this->getTitleProtection();
2605
2606                                 if ( $title_protection ) {
2607                                         $now = wfTimestampNow();
2608                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2609
2610                                         if ( !$expiry || $expiry > $now ) {
2611                                                 // Apply the restrictions
2612                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2613                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2614                                         } else { // Get rid of the old restrictions
2615                                                 Title::purgeExpiredRestrictions();
2616                                                 $this->mTitleProtection = false;
2617                                         }
2618                                 } else {
2619                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2620                                 }
2621                                 $this->mRestrictionsLoaded = true;
2622                         }
2623                 }
2624         }
2625
2626         /**
2627          * Flush the protection cache in this object and force reload from the database.
2628          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2629          */
2630         public function flushRestrictions() {
2631                 $this->mRestrictionsLoaded = false;
2632                 $this->mTitleProtection = null;
2633         }
2634
2635         /**
2636          * Purge expired restrictions from the page_restrictions table
2637          */
2638         static function purgeExpiredRestrictions() {
2639                 $dbw = wfGetDB( DB_MASTER );
2640                 $dbw->delete(
2641                         'page_restrictions',
2642                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2643                         __METHOD__
2644                 );
2645
2646                 $dbw->delete(
2647                         'protected_titles',
2648                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2649                         __METHOD__
2650                 );
2651         }
2652
2653         /**
2654          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2655          *
2656          * @return Bool
2657          */
2658         public function hasSubpages() {
2659                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2660                         # Duh
2661                         return false;
2662                 }
2663
2664                 # We dynamically add a member variable for the purpose of this method
2665                 # alone to cache the result.  There's no point in having it hanging
2666                 # around uninitialized in every Title object; therefore we only add it
2667                 # if needed and don't declare it statically.
2668                 if ( isset( $this->mHasSubpages ) ) {
2669                         return $this->mHasSubpages;
2670                 }
2671
2672                 $subpages = $this->getSubpages( 1 );
2673                 if ( $subpages instanceof TitleArray ) {
2674                         return $this->mHasSubpages = (bool)$subpages->count();
2675                 }
2676                 return $this->mHasSubpages = false;
2677         }
2678
2679         /**
2680          * Get all subpages of this page.
2681          *
2682          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2683          * @return mixed TitleArray, or empty array if this page's namespace
2684          *  doesn't allow subpages
2685          */
2686         public function getSubpages( $limit = -1 ) {
2687                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2688                         return array();
2689                 }
2690
2691                 $dbr = wfGetDB( DB_SLAVE );
2692                 $conds['page_namespace'] = $this->getNamespace();
2693                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2694                 $options = array();
2695                 if ( $limit > -1 ) {
2696                         $options['LIMIT'] = $limit;
2697                 }
2698                 return $this->mSubpages = TitleArray::newFromResult(
2699                         $dbr->select( 'page',
2700                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2701                                 $conds,
2702                                 __METHOD__,
2703                                 $options
2704                         )
2705                 );
2706         }
2707
2708         /**
2709          * Is there a version of this page in the deletion archive?
2710          *
2711          * @return Int the number of archived revisions
2712          */
2713         public function isDeleted() {
2714                 if ( $this->getNamespace() < 0 ) {
2715                         $n = 0;
2716                 } else {
2717                         $dbr = wfGetDB( DB_SLAVE );
2718
2719                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2720                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2721                                 __METHOD__
2722                         );
2723                         if ( $this->getNamespace() == NS_FILE ) {
2724                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2725                                         array( 'fa_name' => $this->getDBkey() ),
2726                                         __METHOD__
2727                                 );
2728                         }
2729                 }
2730                 return (int)$n;
2731         }
2732
2733         /**
2734          * Is there a version of this page in the deletion archive?
2735          *
2736          * @return Boolean
2737          */
2738         public function isDeletedQuick() {
2739                 if ( $this->getNamespace() < 0 ) {
2740                         return false;
2741                 }
2742                 $dbr = wfGetDB( DB_SLAVE );
2743                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2744                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2745                         __METHOD__
2746                 );
2747                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2748                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2749                                 array( 'fa_name' => $this->getDBkey() ),
2750                                 __METHOD__
2751                         );
2752                 }
2753                 return $deleted;
2754         }
2755
2756         /**
2757          * Get the article ID for this Title from the link cache,
2758          * adding it if necessary
2759          *
2760          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2761          *  for update
2762          * @return Int the ID
2763          */
2764         public function getArticleID( $flags = 0 ) {
2765                 if ( $this->getNamespace() < 0 ) {
2766                         return $this->mArticleID = 0;
2767                 }
2768                 $linkCache = LinkCache::singleton();
2769                 if ( $flags & self::GAID_FOR_UPDATE ) {
2770                         $oldUpdate = $linkCache->forUpdate( true );
2771                         $linkCache->clearLink( $this );
2772                         $this->mArticleID = $linkCache->addLinkObj( $this );
2773                         $linkCache->forUpdate( $oldUpdate );
2774                 } else {
2775                         if ( -1 == $this->mArticleID ) {
2776                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2777                         }
2778                 }
2779                 return $this->mArticleID;
2780         }
2781
2782         /**
2783          * Is this an article that is a redirect page?
2784          * Uses link cache, adding it if necessary
2785          *
2786          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2787          * @return Bool
2788          */
2789         public function isRedirect( $flags = 0 ) {
2790                 if ( !is_null( $this->mRedirect ) ) {
2791                         return $this->mRedirect;
2792                 }
2793                 # Calling getArticleID() loads the field from cache as needed
2794                 if ( !$this->getArticleID( $flags ) ) {
2795                         return $this->mRedirect = false;
2796                 }
2797                 $linkCache = LinkCache::singleton();
2798                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2799
2800                 return $this->mRedirect;
2801         }
2802
2803         /**
2804          * What is the length of this page?
2805          * Uses link cache, adding it if necessary
2806          *
2807          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2808          * @return Int
2809          */
2810         public function getLength( $flags = 0 ) {
2811                 if ( $this->mLength != -1 ) {
2812                         return $this->mLength;
2813                 }
2814                 # Calling getArticleID() loads the field from cache as needed
2815                 if ( !$this->getArticleID( $flags ) ) {
2816                         return $this->mLength = 0;
2817                 }
2818                 $linkCache = LinkCache::singleton();
2819                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2820
2821                 return $this->mLength;
2822         }
2823
2824         /**
2825          * What is the page_latest field for this page?
2826          *
2827          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2828          * @return Int or 0 if the page doesn't exist
2829          */
2830         public function getLatestRevID( $flags = 0 ) {
2831                 if ( $this->mLatestID !== false ) {
2832                         return intval( $this->mLatestID );
2833                 }
2834                 # Calling getArticleID() loads the field from cache as needed
2835                 if ( !$this->getArticleID( $flags ) ) {
2836                         return $this->mLatestID = 0;
2837                 }
2838                 $linkCache = LinkCache::singleton();
2839                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2840
2841                 return $this->mLatestID;
2842         }
2843
2844         /**
2845          * This clears some fields in this object, and clears any associated
2846          * keys in the "bad links" section of the link cache.
2847          *
2848          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2849          * loading of the new page_id. It's also called from
2850          * WikiPage::doDeleteArticle()
2851          *
2852          * @param $newid Int the new Article ID
2853          */
2854         public function resetArticleID( $newid ) {
2855                 $linkCache = LinkCache::singleton();
2856                 $linkCache->clearLink( $this );
2857
2858                 if ( $newid === false ) {
2859                         $this->mArticleID = -1;
2860                 } else {
2861                         $this->mArticleID = intval( $newid );
2862                 }
2863                 $this->mRestrictionsLoaded = false;
2864                 $this->mRestrictions = array();
2865                 $this->mRedirect = null;
2866                 $this->mLength = -1;
2867                 $this->mLatestID = false;
2868                 $this->mEstimateRevisions = null;
2869         }
2870
2871         /**
2872          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2873          *
2874          * @param $text String containing title to capitalize
2875          * @param $ns int namespace index, defaults to NS_MAIN
2876          * @return String containing capitalized title
2877          */
2878         public static function capitalize( $text, $ns = NS_MAIN ) {
2879                 global $wgContLang;
2880
2881                 if ( MWNamespace::isCapitalized( $ns ) ) {
2882                         return $wgContLang->ucfirst( $text );
2883                 } else {
2884                         return $text;
2885                 }
2886         }
2887
2888         /**
2889          * Secure and split - main initialisation function for this object
2890          *
2891          * Assumes that mDbkeyform has been set, and is urldecoded
2892          * and uses underscores, but not otherwise munged.  This function
2893          * removes illegal characters, splits off the interwiki and
2894          * namespace prefixes, sets the other forms, and canonicalizes
2895          * everything.
2896          *
2897          * @return Bool true on success
2898          */
2899         private function secureAndSplit() {
2900                 global $wgContLang, $wgLocalInterwiki;
2901
2902                 # Initialisation
2903                 $this->mInterwiki = $this->mFragment = '';
2904                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2905
2906                 $dbkey = $this->mDbkeyform;
2907
2908                 # Strip Unicode bidi override characters.
2909                 # Sometimes they slip into cut-n-pasted page titles, where the
2910                 # override chars get included in list displays.
2911                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2912
2913                 # Clean up whitespace
2914                 # Note: use of the /u option on preg_replace here will cause
2915                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2916                 # conveniently disabling them.
2917                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2918                 $dbkey = trim( $dbkey, '_' );
2919
2920                 if ( $dbkey == '' ) {
2921                         return false;
2922                 }
2923
2924                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2925                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2926                         return false;
2927                 }
2928
2929                 $this->mDbkeyform = $dbkey;
2930
2931                 # Initial colon indicates main namespace rather than specified default
2932                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2933                 if ( ':' == $dbkey[0] ) {
2934                         $this->mNamespace = NS_MAIN;
2935                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2936                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2937                 }
2938
2939                 # Namespace or interwiki prefix
2940                 $firstPass = true;
2941                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2942                 do {
2943                         $m = array();
2944                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2945                                 $p = $m[1];
2946                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2947                                         # Ordinary namespace
2948                                         $dbkey = $m[2];
2949                                         $this->mNamespace = $ns;
2950                                         # For Talk:X pages, check if X has a "namespace" prefix
2951                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2952                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2953                                                         # Disallow Talk:File:x type titles...
2954                                                         return false;
2955                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2956                                                         # Disallow Talk:Interwiki:x type titles...
2957                                                         return false;
2958                                                 }
2959                                         }
2960                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2961                                         if ( !$firstPass ) {
2962                                                 # Can't make a local interwiki link to an interwiki link.
2963                                                 # That's just crazy!
2964                                                 return false;
2965                                         }
2966
2967                                         # Interwiki link
2968                                         $dbkey = $m[2];
2969                                         $this->mInterwiki = $wgContLang->lc( $p );
2970
2971                                         # Redundant interwiki prefix to the local wiki
2972                                         if ( $wgLocalInterwiki !== false
2973                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2974                                         {
2975                                                 if ( $dbkey == '' ) {
2976                                                         # Can't have an empty self-link
2977                                                         return false;
2978                                                 }
2979                                                 $this->mInterwiki = '';
2980                                                 $firstPass = false;
2981                                                 # Do another namespace split...
2982                                                 continue;
2983                                         }
2984
2985                                         # If there's an initial colon after the interwiki, that also
2986                                         # resets the default namespace
2987                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2988                                                 $this->mNamespace = NS_MAIN;
2989                                                 $dbkey = substr( $dbkey, 1 );
2990                                         }
2991                                 }
2992                                 # If there's no recognized interwiki or namespace,
2993                                 # then let the colon expression be part of the title.
2994                         }
2995                         break;
2996                 } while ( true );
2997
2998                 # We already know that some pages won't be in the database!
2999                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3000                         $this->mArticleID = 0;
3001                 }
3002                 $fragment = strstr( $dbkey, '#' );
3003                 if ( false !== $fragment ) {
3004                         $this->setFragment( $fragment );
3005                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3006                         # remove whitespace again: prevents "Foo_bar_#"
3007                         # becoming "Foo_bar_"
3008                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3009                 }
3010
3011                 # Reject illegal characters.
3012                 $rxTc = self::getTitleInvalidRegex();
3013                 if ( preg_match( $rxTc, $dbkey ) ) {
3014                         return false;
3015                 }
3016
3017                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3018                 # reachable due to the way web browsers deal with 'relative' URLs.
3019                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3020                 if ( strpos( $dbkey, '.' ) !== false &&
3021                          ( $dbkey === '.' || $dbkey === '..' ||
3022                            strpos( $dbkey, './' ) === 0  ||
3023                            strpos( $dbkey, '../' ) === 0 ||
3024                            strpos( $dbkey, '/./' ) !== false ||
3025                            strpos( $dbkey, '/../' ) !== false  ||
3026                            substr( $dbkey, -2 ) == '/.' ||
3027                            substr( $dbkey, -3 ) == '/..' ) )
3028                 {
3029                         return false;
3030                 }
3031
3032                 # Magic tilde sequences? Nu-uh!
3033                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3034                         return false;
3035                 }
3036
3037                 # Limit the size of titles to 255 bytes. This is typically the size of the
3038                 # underlying database field. We make an exception for special pages, which
3039                 # don't need to be stored in the database, and may edge over 255 bytes due
3040                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3041                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3042                   strlen( $dbkey ) > 512 )
3043                 {
3044                         return false;
3045                 }
3046
3047                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3048                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3049                 # other site might be case-sensitive.
3050                 $this->mUserCaseDBKey = $dbkey;
3051                 if ( $this->mInterwiki == '' ) {
3052                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3053                 }
3054
3055                 # Can't make a link to a namespace alone... "empty" local links can only be
3056                 # self-links with a fragment identifier.
3057                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3058                         return false;
3059                 }
3060
3061                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3062                 // IP names are not allowed for accounts, and can only be referring to
3063                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3064                 // there are numerous ways to present the same IP. Having sp:contribs scan
3065                 // them all is silly and having some show the edits and others not is
3066                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3067                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3068                         ? IP::sanitizeIP( $dbkey )
3069                         : $dbkey;
3070
3071                 // Any remaining initial :s are illegal.
3072                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3073                         return false;
3074                 }
3075
3076                 # Fill fields
3077                 $this->mDbkeyform = $dbkey;
3078                 $this->mUrlform = wfUrlencode( $dbkey );
3079
3080                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3081
3082                 return true;
3083         }
3084
3085         /**
3086          * Get an array of Title objects linking to this Title
3087          * Also stores the IDs in the link cache.
3088          *
3089          * WARNING: do not use this function on arbitrary user-supplied titles!
3090          * On heavily-used templates it will max out the memory.
3091          *
3092          * @param $options Array: may be FOR UPDATE
3093          * @param $table String: table name
3094          * @param $prefix String: fields prefix
3095          * @return Array of Title objects linking here
3096          */
3097         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3098                 if ( count( $options ) > 0 ) {
3099                         $db = wfGetDB( DB_MASTER );
3100                 } else {
3101                         $db = wfGetDB( DB_SLAVE );
3102                 }
3103
3104                 $res = $db->select(
3105                         array( 'page', $table ),
3106                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3107                         array(
3108                                 "{$prefix}_from=page_id",
3109                                 "{$prefix}_namespace" => $this->getNamespace(),
3110                                 "{$prefix}_title"     => $this->getDBkey() ),
3111                         __METHOD__,
3112                         $options
3113                 );
3114
3115                 $retVal = array();
3116                 if ( $res->numRows() ) {
3117                         $linkCache = LinkCache::singleton();
3118                         foreach ( $res as $row ) {
3119                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3120                                 if ( $titleObj ) {
3121                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3122                                         $retVal[] = $titleObj;
3123                                 }
3124                         }
3125                 }
3126                 return $retVal;
3127         }
3128
3129         /**
3130          * Get an array of Title objects using this Title as a template
3131          * Also stores the IDs in the link cache.
3132          *
3133          * WARNING: do not use this function on arbitrary user-supplied titles!
3134          * On heavily-used templates it will max out the memory.
3135          *
3136          * @param $options Array: may be FOR UPDATE
3137          * @return Array of Title the Title objects linking here
3138          */
3139         public function getTemplateLinksTo( $options = array() ) {
3140                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3141         }
3142
3143         /**
3144          * Get an array of Title objects linked from this Title
3145          * Also stores the IDs in the link cache.
3146          *
3147          * WARNING: do not use this function on arbitrary user-supplied titles!
3148          * On heavily-used templates it will max out the memory.
3149          *
3150          * @param $options Array: may be FOR UPDATE
3151          * @param $table String: table name
3152          * @param $prefix String: fields prefix
3153          * @return Array of Title objects linking here
3154          */
3155         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3156                 $id = $this->getArticleId();
3157
3158                 # If the page doesn't exist; there can't be any link from this page
3159                 if ( !$id ) {
3160                         return array();
3161                 }
3162
3163                 if ( count( $options ) > 0 ) {
3164                         $db = wfGetDB( DB_MASTER );
3165                 } else {
3166                         $db = wfGetDB( DB_SLAVE );
3167                 }
3168
3169                 $namespaceFiled = "{$prefix}_namespace";
3170                 $titleField = "{$prefix}_title";
3171
3172                 $res = $db->select(
3173                         array( $table, 'page' ),
3174                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3175                         array( "{$prefix}_from" => $id ),
3176                         __METHOD__,
3177                         $options,
3178                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3179                 );
3180
3181                 $retVal = array();
3182                 if ( $res->numRows() ) {
3183                         $linkCache = LinkCache::singleton();
3184                         foreach ( $res as $row ) {
3185                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3186                                 if ( $titleObj ) {
3187                                         if ( $row->page_id ) {
3188                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3189                                         } else {
3190                                                 $linkCache->addBadLinkObj( $titleObj );
3191                                         }
3192                                         $retVal[] = $titleObj;
3193                                 }
3194                         }
3195                 }
3196                 return $retVal;
3197         }
3198
3199         /**
3200          * Get an array of Title objects used on this Title as a template
3201          * Also stores the IDs in the link cache.
3202          *
3203          * WARNING: do not use this function on arbitrary user-supplied titles!
3204          * On heavily-used templates it will max out the memory.
3205          *
3206          * @param $options Array: may be FOR UPDATE
3207          * @return Array of Title the Title objects used here
3208          */
3209         public function getTemplateLinksFrom( $options = array() ) {
3210                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3211         }
3212
3213         /**
3214          * Get an array of Title objects referring to non-existent articles linked from this page
3215          *
3216          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3217          * @return Array of Title the Title objects
3218          */
3219         public function getBrokenLinksFrom() {
3220                 if ( $this->getArticleId() == 0 ) {
3221                         # All links from article ID 0 are false positives
3222                         return array();
3223                 }
3224
3225                 $dbr = wfGetDB( DB_SLAVE );
3226                 $res = $dbr->select(
3227                         array( 'page', 'pagelinks' ),
3228                         array( 'pl_namespace', 'pl_title' ),
3229                         array(
3230                                 'pl_from' => $this->getArticleId(),
3231                                 'page_namespace IS NULL'
3232                         ),
3233                         __METHOD__, array(),
3234                         array(
3235                                 'page' => array(
3236                                         'LEFT JOIN',
3237                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3238                                 )
3239                         )
3240                 );
3241
3242                 $retVal = array();
3243                 foreach ( $res as $row ) {
3244                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3245                 }
3246                 return $retVal;
3247         }
3248
3249
3250         /**
3251          * Get a list of URLs to purge from the Squid cache when this
3252          * page changes
3253          *
3254          * @return Array of String the URLs
3255          */
3256         public function getSquidURLs() {
3257                 global $wgContLang;
3258
3259                 $urls = array(
3260                         $this->getInternalURL(),
3261                         $this->getInternalURL( 'action=history' )
3262                 );
3263
3264                 // purge variant urls as well
3265                 if ( $wgContLang->hasVariants() ) {
3266                         $variants = $wgContLang->getVariants();
3267                         foreach ( $variants as $vCode ) {
3268                                 $urls[] = $this->getInternalURL( '', $vCode );
3269                         }
3270                 }
3271
3272                 return $urls;
3273         }
3274
3275         /**
3276          * Purge all applicable Squid URLs
3277          */
3278         public function purgeSquid() {
3279                 global $wgUseSquid;
3280                 if ( $wgUseSquid ) {
3281                         $urls = $this->getSquidURLs();
3282                         $u = new SquidUpdate( $urls );
3283                         $u->doUpdate();
3284                 }
3285         }
3286
3287         /**
3288          * Move this page without authentication
3289          *
3290          * @param $nt Title the new page Title
3291          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3292          */
3293         public function moveNoAuth( &$nt ) {
3294                 return $this->moveTo( $nt, false );
3295         }
3296
3297         /**
3298          * Check whether a given move operation would be valid.
3299          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3300          *
3301          * @param $nt Title the new title
3302          * @param $auth Bool indicates whether $wgUser's permissions
3303          *  should be checked
3304          * @param $reason String is the log summary of the move, used for spam checking
3305          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3306          */
3307         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3308                 global $wgUser;
3309
3310                 $errors = array();
3311                 if ( !$nt ) {
3312                         // Normally we'd add this to $errors, but we'll get
3313                         // lots of syntax errors if $nt is not an object
3314                         return array( array( 'badtitletext' ) );
3315                 }
3316                 if ( $this->equals( $nt ) ) {
3317                         $errors[] = array( 'selfmove' );
3318                 }
3319                 if ( !$this->isMovable() ) {
3320                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3321                 }
3322                 if ( $nt->getInterwiki() != '' ) {
3323                         $errors[] = array( 'immobile-target-namespace-iw' );
3324                 }
3325                 if ( !$nt->isMovable() ) {
3326                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3327                 }
3328
3329                 $oldid = $this->getArticleID();
3330                 $newid = $nt->getArticleID();
3331
3332                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3333                         $errors[] = array( 'articleexists' );
3334                 }
3335                 if ( ( $this->getDBkey() == '' ) ||
3336                          ( !$oldid ) ||
3337                          ( $nt->getDBkey() == '' ) ) {
3338                         $errors[] = array( 'badarticleerror' );
3339                 }
3340
3341                 // Image-specific checks
3342                 if ( $this->getNamespace() == NS_FILE ) {
3343                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3344                 }
3345
3346                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3347                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3348                 }
3349
3350                 if ( $auth ) {
3351                         $errors = wfMergeErrorArrays( $errors,
3352                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3353                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3354                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3355                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3356                 }
3357
3358                 $match = EditPage::matchSummarySpamRegex( $reason );
3359                 if ( $match !== false ) {
3360                         // This is kind of lame, won't display nice
3361                         $errors[] = array( 'spamprotectiontext' );
3362                 }
3363
3364                 $err = null;
3365                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3366                         $errors[] = array( 'hookaborted', $err );
3367                 }
3368
3369                 # The move is allowed only if (1) the target doesn't exist, or
3370                 # (2) the target is a redirect to the source, and has no history
3371                 # (so we can undo bad moves right after they're done).
3372
3373                 if ( 0 != $newid ) { # Target exists; check for validity
3374                         if ( !$this->isValidMoveTarget( $nt ) ) {
3375                                 $errors[] = array( 'articleexists' );
3376                         }
3377                 } else {
3378                         $tp = $nt->getTitleProtection();
3379                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3380                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3381                                 $errors[] = array( 'cantmove-titleprotected' );
3382                         }
3383                 }
3384                 if ( empty( $errors ) ) {
3385                         return true;
3386                 }
3387                 return $errors;
3388         }
3389
3390         /**
3391          * Check if the requested move target is a valid file move target
3392          * @param Title $nt Target title
3393          * @return array List of errors
3394          */
3395         protected function validateFileMoveOperation( $nt ) {
3396                 global $wgUser;
3397
3398                 $errors = array();
3399
3400                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3401
3402                 $file = wfLocalFile( $this );
3403                 if ( $file->exists() ) {
3404                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3405                                 $errors[] = array( 'imageinvalidfilename' );
3406                         }
3407                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3408                                 $errors[] = array( 'imagetypemismatch' );
3409                         }
3410                 }
3411
3412                 if ( $nt->getNamespace() != NS_FILE ) {
3413                         $errors[] = array( 'imagenocrossnamespace' );
3414                         // From here we want to do checks on a file object, so if we can't
3415                         // create one, we must return.
3416                         return $errors;
3417                 }
3418
3419                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3420
3421                 $destFile = wfLocalFile( $nt );
3422                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3423                         $errors[] = array( 'file-exists-sharedrepo' );
3424                 }
3425
3426                 return $errors;
3427         }
3428
3429         /**
3430          * Move a title to a new location
3431          *
3432          * @param $nt Title the new title
3433          * @param $auth Bool indicates whether $wgUser's permissions
3434          *  should be checked
3435          * @param $reason String the reason for the move
3436          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3437          *  Ignored if the user doesn't have the suppressredirect right.
3438          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3439          */
3440         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3441                 global $wgUser;
3442                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3443                 if ( is_array( $err ) ) {
3444                         // Auto-block user's IP if the account was "hard" blocked
3445                         $wgUser->spreadAnyEditBlock();
3446                         return $err;
3447                 }
3448
3449                 // If it is a file, move it first.
3450                 // It is done before all other moving stuff is done because it's hard to revert.
3451                 $dbw = wfGetDB( DB_MASTER );
3452                 if ( $this->getNamespace() == NS_FILE ) {
3453                         $file = wfLocalFile( $this );
3454                         if ( $file->exists() ) {
3455                                 $status = $file->move( $nt );
3456                                 if ( !$status->isOk() ) {
3457                                         return $status->getErrorsArray();
3458                                 }
3459                         }
3460                         // Clear RepoGroup process cache
3461                         RepoGroup::singleton()->clearCache( $this );
3462                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3463                 }
3464
3465                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3466                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3467                 $protected = $this->isProtected();
3468
3469                 // Do the actual move
3470                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3471                 if ( is_array( $err ) ) {
3472                         # @todo FIXME: What about the File we have already moved?
3473                         $dbw->rollback();
3474                         return $err;
3475                 }
3476
3477                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3478                 // cl_timestamp, which may disturb time-based lists on some sites.
3479                 $prefixes = $dbw->select(
3480                         'categorylinks',
3481                         array( 'cl_sortkey_prefix', 'cl_to' ),
3482                         array( 'cl_from' => $pageid ),
3483                         __METHOD__
3484                 );
3485                 foreach ( $prefixes as $prefixRow ) {
3486                         $prefix = $prefixRow->cl_sortkey_prefix;
3487                         $catTo = $prefixRow->cl_to;
3488                         $dbw->update( 'categorylinks',
3489                                 array(
3490                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3491                                                 $nt->getCategorySortkey( $prefix ) ),
3492                                         'cl_timestamp=cl_timestamp' ),
3493                                 array(
3494                                         'cl_from' => $pageid,
3495                                         'cl_to' => $catTo ),
3496                                 __METHOD__
3497                         );
3498                 }
3499
3500                 $redirid = $this->getArticleID();
3501
3502                 if ( $protected ) {
3503                         # Protect the redirect title as the title used to be...
3504                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3505                                 array(
3506                                         'pr_page'    => $redirid,
3507                                         'pr_type'    => 'pr_type',
3508                                         'pr_level'   => 'pr_level',
3509                                         'pr_cascade' => 'pr_cascade',
3510                                         'pr_user'    => 'pr_user',
3511                                         'pr_expiry'  => 'pr_expiry'
3512                                 ),
3513                                 array( 'pr_page' => $pageid ),
3514                                 __METHOD__,
3515                                 array( 'IGNORE' )
3516                         );
3517                         # Update the protection log
3518                         $log = new LogPage( 'protect' );
3519                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3520                         if ( $reason ) {
3521                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3522                         }
3523                         // @todo FIXME: $params?
3524                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3525                 }
3526
3527                 # Update watchlists
3528                 $oldnamespace = $this->getNamespace() & ~1;
3529                 $newnamespace = $nt->getNamespace() & ~1;
3530                 $oldtitle = $this->getDBkey();
3531                 $newtitle = $nt->getDBkey();
3532
3533                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3534                         WatchedItem::duplicateEntries( $this, $nt );
3535                 }
3536
3537                 $dbw->commit();
3538
3539                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3540                 return true;
3541         }
3542
3543         /**
3544          * Move page to a title which is either a redirect to the
3545          * source page or nonexistent
3546          *
3547          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3548          * @param $reason String The reason for the move
3549          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3550          *   if the user doesn't have the suppressredirect right
3551          */
3552         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3553                 global $wgUser, $wgContLang;
3554
3555                 if ( $nt->exists() ) {
3556                         $moveOverRedirect = true;
3557                         $logType = 'move_redir';
3558                 } else {
3559                         $moveOverRedirect = false;
3560                         $logType = 'move';
3561                 }
3562
3563                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3564
3565                 $logEntry = new ManualLogEntry( 'move', $logType );
3566                 $logEntry->setPerformer( $wgUser );
3567                 $logEntry->setTarget( $this );
3568                 $logEntry->setComment( $reason );
3569                 $logEntry->setParameters( array(
3570                         '4::target' => $nt->getPrefixedText(),
3571                         '5::noredir' => $redirectSuppressed ? '1': '0',
3572                 ) );
3573
3574                 $formatter = LogFormatter::newFromEntry( $logEntry );
3575                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3576                 $comment = $formatter->getPlainActionText();
3577                 if ( $reason ) {
3578                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3579                 }
3580                 # Truncate for whole multibyte characters.
3581                 $comment = $wgContLang->truncate( $comment, 255 );
3582
3583                 $oldid = $this->getArticleID();
3584                 $latest = $this->getLatestRevID();
3585
3586                 $dbw = wfGetDB( DB_MASTER );
3587
3588                 $newpage = WikiPage::factory( $nt );
3589
3590                 if ( $moveOverRedirect ) {
3591                         $newid = $nt->getArticleID();
3592
3593                         # Delete the old redirect. We don't save it to history since
3594                         # by definition if we've got here it's rather uninteresting.
3595                         # We have to remove it so that the next step doesn't trigger
3596                         # a conflict on the unique namespace+title index...
3597                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3598
3599                         $newpage->doDeleteUpdates( $newid );
3600                 }
3601
3602                 # Save a null revision in the page's history notifying of the move
3603                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3604                 if ( !is_object( $nullRevision ) ) {
3605                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3606                 }
3607                 $nullRevId = $nullRevision->insertOn( $dbw );
3608
3609                 # Change the name of the target page:
3610                 $dbw->update( 'page',
3611                         /* SET */ array(
3612                                 'page_namespace' => $nt->getNamespace(),
3613                                 'page_title'     => $nt->getDBkey(),
3614                         ),
3615                         /* WHERE */ array( 'page_id' => $oldid ),
3616                         __METHOD__
3617                 );
3618
3619                 $this->resetArticleID( 0 );
3620                 $nt->resetArticleID( $oldid );
3621
3622                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3623
3624                 wfRunHooks( 'NewRevisionFromEditComplete',
3625                         array( $newpage, $nullRevision, $latest, $wgUser ) );
3626
3627                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3628
3629                 # Recreate the redirect, this time in the other direction.
3630                 if ( $redirectSuppressed ) {
3631                         WikiPage::onArticleDelete( $this );
3632                 } else {
3633                         $mwRedir = MagicWord::get( 'redirect' );
3634                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3635                         $redirectArticle = WikiPage::factory( $this );
3636                         $newid = $redirectArticle->insertOn( $dbw );
3637                         if ( $newid ) { // sanity
3638                                 $redirectRevision = new Revision( array(
3639                                         'page'    => $newid,
3640                                         'comment' => $comment,
3641                                         'text'    => $redirectText ) );
3642                                 $redirectRevision->insertOn( $dbw );
3643                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3644
3645                                 wfRunHooks( 'NewRevisionFromEditComplete',
3646                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3647
3648                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3649                         }
3650                 }
3651
3652                 # Log the move
3653                 $logid = $logEntry->insert();
3654                 $logEntry->publish( $logid );
3655         }
3656
3657         /**
3658          * Move this page's subpages to be subpages of $nt
3659          *
3660          * @param $nt Title Move target
3661          * @param $auth bool Whether $wgUser's permissions should be checked
3662          * @param $reason string The reason for the move
3663          * @param $createRedirect bool Whether to create redirects from the old subpages to
3664          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3665          * @return mixed array with old page titles as keys, and strings (new page titles) or
3666          *     arrays (errors) as values, or an error array with numeric indices if no pages
3667          *     were moved
3668          */
3669         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3670                 global $wgMaximumMovedPages;
3671                 // Check permissions
3672                 if ( !$this->userCan( 'move-subpages' ) ) {
3673                         return array( 'cant-move-subpages' );
3674                 }
3675                 // Do the source and target namespaces support subpages?
3676                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3677                         return array( 'namespace-nosubpages',
3678                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3679                 }
3680                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3681                         return array( 'namespace-nosubpages',
3682                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3683                 }
3684
3685                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3686                 $retval = array();
3687                 $count = 0;
3688                 foreach ( $subpages as $oldSubpage ) {
3689                         $count++;
3690                         if ( $count > $wgMaximumMovedPages ) {
3691                                 $retval[$oldSubpage->getPrefixedTitle()] =
3692                                                 array( 'movepage-max-pages',
3693                                                         $wgMaximumMovedPages );
3694                                 break;
3695                         }
3696
3697                         // We don't know whether this function was called before
3698                         // or after moving the root page, so check both
3699                         // $this and $nt
3700                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3701                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3702                         {
3703                                 // When moving a page to a subpage of itself,
3704                                 // don't move it twice
3705                                 continue;
3706                         }
3707                         $newPageName = preg_replace(
3708                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3709                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3710                                         $oldSubpage->getDBkey() );
3711                         if ( $oldSubpage->isTalkPage() ) {
3712                                 $newNs = $nt->getTalkPage()->getNamespace();
3713                         } else {
3714                                 $newNs = $nt->getSubjectPage()->getNamespace();
3715                         }
3716                         # Bug 14385: we need makeTitleSafe because the new page names may
3717                         # be longer than 255 characters.
3718                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3719
3720                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3721                         if ( $success === true ) {
3722                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3723                         } else {
3724                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3725                         }
3726                 }
3727                 return $retval;
3728         }
3729
3730         /**
3731          * Checks if this page is just a one-rev redirect.
3732          * Adds lock, so don't use just for light purposes.
3733          *
3734          * @return Bool
3735          */
3736         public function isSingleRevRedirect() {
3737                 $dbw = wfGetDB( DB_MASTER );
3738                 # Is it a redirect?
3739                 $row = $dbw->selectRow( 'page',
3740                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3741                         $this->pageCond(),
3742                         __METHOD__,
3743                         array( 'FOR UPDATE' )
3744                 );
3745                 # Cache some fields we may want
3746                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3747                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3748                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3749                 if ( !$this->mRedirect ) {
3750                         return false;
3751                 }
3752                 # Does the article have a history?
3753                 $row = $dbw->selectField( array( 'page', 'revision' ),
3754                         'rev_id',
3755                         array( 'page_namespace' => $this->getNamespace(),
3756                                 'page_title' => $this->getDBkey(),
3757                                 'page_id=rev_page',
3758                                 'page_latest != rev_id'
3759                         ),
3760                         __METHOD__,
3761                         array( 'FOR UPDATE' )
3762                 );
3763                 # Return true if there was no history
3764                 return ( $row === false );
3765         }
3766
3767         /**
3768          * Checks if $this can be moved to a given Title
3769          * - Selects for update, so don't call it unless you mean business
3770          *
3771          * @param $nt Title the new title to check
3772          * @return Bool
3773          */
3774         public function isValidMoveTarget( $nt ) {
3775                 # Is it an existing file?
3776                 if ( $nt->getNamespace() == NS_FILE ) {
3777                         $file = wfLocalFile( $nt );
3778                         if ( $file->exists() ) {
3779                                 wfDebug( __METHOD__ . ": file exists\n" );
3780                                 return false;
3781                         }
3782                 }
3783                 # Is it a redirect with no history?
3784                 if ( !$nt->isSingleRevRedirect() ) {
3785                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3786                         return false;
3787                 }
3788                 # Get the article text
3789                 $rev = Revision::newFromTitle( $nt );
3790                 if( !is_object( $rev ) ){
3791                         return false;
3792                 }
3793                 $text = $rev->getText();
3794                 # Does the redirect point to the source?
3795                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3796                 $m = array();
3797                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3798                         $redirTitle = Title::newFromText( $m[1] );
3799                         if ( !is_object( $redirTitle ) ||
3800                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3801                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3802                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3803                                 return false;
3804                         }
3805                 } else {
3806                         # Fail safe
3807                         wfDebug( __METHOD__ . ": failsafe\n" );
3808                         return false;
3809                 }
3810                 return true;
3811         }
3812
3813         /**
3814          * Get categories to which this Title belongs and return an array of
3815          * categories' names.
3816          *
3817          * @return Array of parents in the form:
3818          *        $parent => $currentarticle
3819          */
3820         public function getParentCategories() {
3821                 global $wgContLang;
3822
3823                 $data = array();
3824
3825                 $titleKey = $this->getArticleId();
3826
3827                 if ( $titleKey === 0 ) {
3828                         return $data;
3829                 }
3830
3831                 $dbr = wfGetDB( DB_SLAVE );
3832
3833                 $res = $dbr->select( 'categorylinks', '*',
3834                         array(
3835                                 'cl_from' => $titleKey,
3836                         ),
3837                         __METHOD__,
3838                         array()
3839                 );
3840
3841                 if ( $dbr->numRows( $res ) > 0 ) {
3842                         foreach ( $res as $row ) {
3843                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3844                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3845                         }
3846                 }
3847                 return $data;
3848         }
3849
3850         /**
3851          * Get a tree of parent categories
3852          *
3853          * @param $children Array with the children in the keys, to check for circular refs
3854          * @return Array Tree of parent categories
3855          */
3856         public function getParentCategoryTree( $children = array() ) {
3857                 $stack = array();
3858                 $parents = $this->getParentCategories();
3859
3860                 if ( $parents ) {
3861                         foreach ( $parents as $parent => $current ) {
3862                                 if ( array_key_exists( $parent, $children ) ) {
3863                                         # Circular reference
3864                                         $stack[$parent] = array();
3865                                 } else {
3866                                         $nt = Title::newFromText( $parent );
3867                                         if ( $nt ) {
3868                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3869                                         }
3870                                 }
3871                         }
3872                 }
3873
3874                 return $stack;
3875         }
3876
3877         /**
3878          * Get an associative array for selecting this title from
3879          * the "page" table
3880          *
3881          * @return Array suitable for the $where parameter of DB::select()
3882          */
3883         public function pageCond() {
3884                 if ( $this->mArticleID > 0 ) {
3885                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3886                         return array( 'page_id' => $this->mArticleID );
3887                 } else {
3888                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3889                 }
3890         }
3891
3892         /**
3893          * Get the revision ID of the previous revision
3894          *
3895          * @param $revId Int Revision ID. Get the revision that was before this one.
3896          * @param $flags Int Title::GAID_FOR_UPDATE
3897          * @return Int|Bool Old revision ID, or FALSE if none exists
3898          */
3899         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3900                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3901                 return $db->selectField( 'revision', 'rev_id',
3902                         array(
3903                                 'rev_page' => $this->getArticleId( $flags ),
3904                                 'rev_id < ' . intval( $revId )
3905                         ),
3906                         __METHOD__,
3907                         array( 'ORDER BY' => 'rev_id DESC' )
3908                 );
3909         }
3910
3911         /**
3912          * Get the revision ID of the next revision
3913          *
3914          * @param $revId Int Revision ID. Get the revision that was after this one.
3915          * @param $flags Int Title::GAID_FOR_UPDATE
3916          * @return Int|Bool Next revision ID, or FALSE if none exists
3917          */
3918         public function getNextRevisionID( $revId, $flags = 0 ) {
3919                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3920                 return $db->selectField( 'revision', 'rev_id',
3921                         array(
3922                                 'rev_page' => $this->getArticleId( $flags ),
3923                                 'rev_id > ' . intval( $revId )
3924                         ),
3925                         __METHOD__,
3926                         array( 'ORDER BY' => 'rev_id' )
3927                 );
3928         }
3929
3930         /**
3931          * Get the first revision of the page
3932          *
3933          * @param $flags Int Title::GAID_FOR_UPDATE
3934          * @return Revision|Null if page doesn't exist
3935          */
3936         public function getFirstRevision( $flags = 0 ) {
3937                 $pageId = $this->getArticleId( $flags );
3938                 if ( $pageId ) {
3939                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3940                         $row = $db->selectRow( 'revision', '*',
3941                                 array( 'rev_page' => $pageId ),
3942                                 __METHOD__,
3943                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3944                         );
3945                         if ( $row ) {
3946                                 return new Revision( $row );
3947                         }
3948                 }
3949                 return null;
3950         }
3951
3952         /**
3953          * Get the oldest revision timestamp of this page
3954          *
3955          * @param $flags Int Title::GAID_FOR_UPDATE
3956          * @return String: MW timestamp
3957          */
3958         public function getEarliestRevTime( $flags = 0 ) {
3959                 $rev = $this->getFirstRevision( $flags );
3960                 return $rev ? $rev->getTimestamp() : null;
3961         }
3962
3963         /**
3964          * Check if this is a new page
3965          *
3966          * @return bool
3967          */
3968         public function isNewPage() {
3969                 $dbr = wfGetDB( DB_SLAVE );
3970                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3971         }
3972
3973         /**
3974          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
3975          *
3976          * @return bool
3977          */
3978         public function isBigDeletion() {
3979                 global $wgDeleteRevisionsLimit;
3980
3981                 if ( !$wgDeleteRevisionsLimit ) {
3982                         return false;
3983                 }
3984
3985                 $revCount = $this->estimateRevisionCount();
3986                 return $revCount > $wgDeleteRevisionsLimit;
3987         }
3988
3989         /**
3990          * Get the  approximate revision count of this page.
3991          *
3992          * @return int
3993          */
3994         public function estimateRevisionCount() {
3995                 if ( !$this->exists() ) {
3996                         return 0;
3997                 }
3998
3999                 if ( $this->mEstimateRevisions === null ) {
4000                         $dbr = wfGetDB( DB_SLAVE );
4001                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4002                                 array( 'rev_page' => $this->getArticleId() ), __METHOD__ );
4003                 }
4004
4005                 return $this->mEstimateRevisions;
4006         }
4007
4008         /**
4009          * Get the number of revisions between the given revision.
4010          * Used for diffs and other things that really need it.
4011          *
4012          * @param $old int|Revision Old revision or rev ID (first before range)
4013          * @param $new int|Revision New revision or rev ID (first after range)
4014          * @return Int Number of revisions between these revisions.
4015          */
4016         public function countRevisionsBetween( $old, $new ) {
4017                 if ( !( $old instanceof Revision ) ) {
4018                         $old = Revision::newFromTitle( $this, (int)$old );
4019                 }
4020                 if ( !( $new instanceof Revision ) ) {
4021                         $new = Revision::newFromTitle( $this, (int)$new );
4022                 }
4023                 if ( !$old || !$new ) {
4024                         return 0; // nothing to compare
4025                 }
4026                 $dbr = wfGetDB( DB_SLAVE );
4027                 return (int)$dbr->selectField( 'revision', 'count(*)',
4028                         array(
4029                                 'rev_page' => $this->getArticleId(),
4030                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4031                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4032                         ),
4033                         __METHOD__
4034                 );
4035         }
4036
4037         /**
4038          * Get the number of authors between the given revision IDs.
4039          * Used for diffs and other things that really need it.
4040          *
4041          * @param $old int|Revision Old revision or rev ID (first before range)
4042          * @param $new int|Revision New revision or rev ID (first after range)
4043          * @param $limit Int Maximum number of authors
4044          * @return Int Number of revision authors between these revisions.
4045          */
4046         public function countAuthorsBetween( $old, $new, $limit ) {
4047                 if ( !( $old instanceof Revision ) ) {
4048                         $old = Revision::newFromTitle( $this, (int)$old );
4049                 }
4050                 if ( !( $new instanceof Revision ) ) {
4051                         $new = Revision::newFromTitle( $this, (int)$new );
4052                 }
4053                 if ( !$old || !$new ) {
4054                         return 0; // nothing to compare
4055                 }
4056                 $dbr = wfGetDB( DB_SLAVE );
4057                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4058                         array(
4059                                 'rev_page' => $this->getArticleID(),
4060                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4061                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4062                         ), __METHOD__,
4063                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4064                 );
4065                 return (int)$dbr->numRows( $res );
4066         }
4067
4068         /**
4069          * Compare with another title.
4070          *
4071          * @param $title Title
4072          * @return Bool
4073          */
4074         public function equals( Title $title ) {
4075                 // Note: === is necessary for proper matching of number-like titles.
4076                 return $this->getInterwiki() === $title->getInterwiki()
4077                         && $this->getNamespace() == $title->getNamespace()
4078                         && $this->getDBkey() === $title->getDBkey();
4079         }
4080
4081         /**
4082          * Check if this title is a subpage of another title
4083          *
4084          * @param $title Title
4085          * @return Bool
4086          */
4087         public function isSubpageOf( Title $title ) {
4088                 return $this->getInterwiki() === $title->getInterwiki()
4089                         && $this->getNamespace() == $title->getNamespace()
4090                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4091         }
4092
4093         /**
4094          * Check if page exists.  For historical reasons, this function simply
4095          * checks for the existence of the title in the page table, and will
4096          * thus return false for interwiki links, special pages and the like.
4097          * If you want to know if a title can be meaningfully viewed, you should
4098          * probably call the isKnown() method instead.
4099          *
4100          * @return Bool
4101          */
4102         public function exists() {
4103                 return $this->getArticleId() != 0;
4104         }
4105
4106         /**
4107          * Should links to this title be shown as potentially viewable (i.e. as
4108          * "bluelinks"), even if there's no record by this title in the page
4109          * table?
4110          *
4111          * This function is semi-deprecated for public use, as well as somewhat
4112          * misleadingly named.  You probably just want to call isKnown(), which
4113          * calls this function internally.
4114          *
4115          * (ISSUE: Most of these checks are cheap, but the file existence check
4116          * can potentially be quite expensive.  Including it here fixes a lot of
4117          * existing code, but we might want to add an optional parameter to skip
4118          * it and any other expensive checks.)
4119          *
4120          * @return Bool
4121          */
4122         public function isAlwaysKnown() {
4123                 if ( $this->mInterwiki != '' ) {
4124                         return true;  // any interwiki link might be viewable, for all we know
4125                 }
4126                 switch( $this->mNamespace ) {
4127                         case NS_MEDIA:
4128                         case NS_FILE:
4129                                 // file exists, possibly in a foreign repo
4130                                 return (bool)wfFindFile( $this );
4131                         case NS_SPECIAL:
4132                                 // valid special page
4133                                 return SpecialPageFactory::exists( $this->getDBkey() );
4134                         case NS_MAIN:
4135                                 // selflink, possibly with fragment
4136                                 return $this->mDbkeyform == '';
4137                         case NS_MEDIAWIKI:
4138                                 // known system message
4139                                 return $this->hasSourceText() !== false;
4140                         default:
4141                                 return false;
4142                 }
4143         }
4144
4145         /**
4146          * Does this title refer to a page that can (or might) be meaningfully
4147          * viewed?  In particular, this function may be used to determine if
4148          * links to the title should be rendered as "bluelinks" (as opposed to
4149          * "redlinks" to non-existent pages).
4150          *
4151          * @return Bool
4152          */
4153         public function isKnown() {
4154                 return $this->isAlwaysKnown() || $this->exists();
4155         }
4156
4157         /**
4158          * Does this page have source text?
4159          *
4160          * @return Boolean
4161          */
4162         public function hasSourceText() {
4163                 if ( $this->exists() ) {
4164                         return true;
4165                 }
4166
4167                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4168                         // If the page doesn't exist but is a known system message, default
4169                         // message content will be displayed, same for language subpages-
4170                         // Use always content language to avoid loading hundreds of languages
4171                         // to get the link color.
4172                         global $wgContLang;
4173                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4174                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4175                         return $message->exists();
4176                 }
4177
4178                 return false;
4179         }
4180
4181         /**
4182          * Get the default message text or false if the message doesn't exist
4183          *
4184          * @return String or false
4185          */
4186         public function getDefaultMessageText() {
4187                 global $wgContLang;
4188
4189                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4190                         return false;
4191                 }
4192
4193                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4194                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4195
4196                 if ( $message->exists() ) {
4197                         return $message->plain();
4198                 } else {
4199                         return false;
4200                 }
4201         }
4202
4203         /**
4204          * Updates page_touched for this page; called from LinksUpdate.php
4205          *
4206          * @return Bool true if the update succeded
4207          */
4208         public function invalidateCache() {
4209                 if ( wfReadOnly() ) {
4210                         return false;
4211                 }
4212                 $dbw = wfGetDB( DB_MASTER );
4213                 $success = $dbw->update(
4214                         'page',
4215                         array( 'page_touched' => $dbw->timestamp() ),
4216                         $this->pageCond(),
4217                         __METHOD__
4218                 );
4219                 HTMLFileCache::clearFileCache( $this );
4220                 return $success;
4221         }
4222
4223         /**
4224          * Update page_touched timestamps and send squid purge messages for
4225          * pages linking to this title. May be sent to the job queue depending
4226          * on the number of links. Typically called on create and delete.
4227          */
4228         public function touchLinks() {
4229                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4230                 $u->doUpdate();
4231
4232                 if ( $this->getNamespace() == NS_CATEGORY ) {
4233                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4234                         $u->doUpdate();
4235                 }
4236         }
4237
4238         /**
4239          * Get the last touched timestamp
4240          *
4241          * @param $db DatabaseBase: optional db
4242          * @return String last-touched timestamp
4243          */
4244         public function getTouched( $db = null ) {
4245                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4246                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4247                 return $touched;
4248         }
4249
4250         /**
4251          * Get the timestamp when this page was updated since the user last saw it.
4252          *
4253          * @param $user User
4254          * @return String|Null
4255          */
4256         public function getNotificationTimestamp( $user = null ) {
4257                 global $wgUser, $wgShowUpdatedMarker;
4258                 // Assume current user if none given
4259                 if ( !$user ) {
4260                         $user = $wgUser;
4261                 }
4262                 // Check cache first
4263                 $uid = $user->getId();
4264                 // avoid isset here, as it'll return false for null entries
4265                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4266                         return $this->mNotificationTimestamp[$uid];
4267                 }
4268                 if ( !$uid || !$wgShowUpdatedMarker ) {
4269                         return $this->mNotificationTimestamp[$uid] = false;
4270                 }
4271                 // Don't cache too much!
4272                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4273                         $this->mNotificationTimestamp = array();
4274                 }
4275                 $dbr = wfGetDB( DB_SLAVE );
4276                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4277                         'wl_notificationtimestamp',
4278                         array( 'wl_namespace' => $this->getNamespace(),
4279                                 'wl_title' => $this->getDBkey(),
4280                                 'wl_user' => $user->getId()
4281                         ),
4282                         __METHOD__
4283                 );
4284                 return $this->mNotificationTimestamp[$uid];
4285         }
4286
4287         /**
4288          * Generate strings used for xml 'id' names in monobook tabs
4289          *
4290          * @param $prepend string defaults to 'nstab-'
4291          * @return String XML 'id' name
4292          */
4293         public function getNamespaceKey( $prepend = 'nstab-' ) {
4294                 global $wgContLang;
4295                 // Gets the subject namespace if this title
4296                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4297                 // Checks if cononical namespace name exists for namespace
4298                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4299                         // Uses canonical namespace name
4300                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4301                 } else {
4302                         // Uses text of namespace
4303                         $namespaceKey = $this->getSubjectNsText();
4304                 }
4305                 // Makes namespace key lowercase
4306                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4307                 // Uses main
4308                 if ( $namespaceKey == '' ) {
4309                         $namespaceKey = 'main';
4310                 }
4311                 // Changes file to image for backwards compatibility
4312                 if ( $namespaceKey == 'file' ) {
4313                         $namespaceKey = 'image';
4314                 }
4315                 return $prepend . $namespaceKey;
4316         }
4317
4318         /**
4319          * Get all extant redirects to this Title
4320          *
4321          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4322          * @return Array of Title redirects to this title
4323          */
4324         public function getRedirectsHere( $ns = null ) {
4325                 $redirs = array();
4326
4327                 $dbr = wfGetDB( DB_SLAVE );
4328                 $where = array(
4329                         'rd_namespace' => $this->getNamespace(),
4330                         'rd_title' => $this->getDBkey(),
4331                         'rd_from = page_id'
4332                 );
4333                 if ( !is_null( $ns ) ) {
4334                         $where['page_namespace'] = $ns;
4335                 }
4336
4337                 $res = $dbr->select(
4338                         array( 'redirect', 'page' ),
4339                         array( 'page_namespace', 'page_title' ),
4340                         $where,
4341                         __METHOD__
4342                 );
4343
4344                 foreach ( $res as $row ) {
4345                         $redirs[] = self::newFromRow( $row );
4346                 }
4347                 return $redirs;
4348         }
4349
4350         /**
4351          * Check if this Title is a valid redirect target
4352          *
4353          * @return Bool
4354          */
4355         public function isValidRedirectTarget() {
4356                 global $wgInvalidRedirectTargets;
4357
4358                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4359                 if ( $this->isSpecial( 'Userlogout' ) ) {
4360                         return false;
4361                 }
4362
4363                 foreach ( $wgInvalidRedirectTargets as $target ) {
4364                         if ( $this->isSpecial( $target ) ) {
4365                                 return false;
4366                         }
4367                 }
4368
4369                 return true;
4370         }
4371
4372         /**
4373          * Get a backlink cache object
4374          *
4375          * @return BacklinkCache
4376          */
4377         function getBacklinkCache() {
4378                 if ( is_null( $this->mBacklinkCache ) ) {
4379                         $this->mBacklinkCache = new BacklinkCache( $this );
4380                 }
4381                 return $this->mBacklinkCache;
4382         }
4383
4384         /**
4385          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4386          *
4387          * @return Boolean
4388          */
4389         public function canUseNoindex() {
4390                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4391
4392                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4393                         ? $wgContentNamespaces
4394                         : $wgExemptFromUserRobotsControl;
4395
4396                 return !in_array( $this->mNamespace, $bannedNamespaces );
4397
4398         }
4399
4400         /**
4401          * Returns the raw sort key to be used for categories, with the specified
4402          * prefix.  This will be fed to Collation::getSortKey() to get a
4403          * binary sortkey that can be used for actual sorting.
4404          *
4405          * @param $prefix string The prefix to be used, specified using
4406          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4407          *   prefix.
4408          * @return string
4409          */
4410         public function getCategorySortkey( $prefix = '' ) {
4411                 $unprefixed = $this->getText();
4412
4413                 // Anything that uses this hook should only depend
4414                 // on the Title object passed in, and should probably
4415                 // tell the users to run updateCollations.php --force
4416                 // in order to re-sort existing category relations.
4417                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4418                 if ( $prefix !== '' ) {
4419                         # Separate with a line feed, so the unprefixed part is only used as
4420                         # a tiebreaker when two pages have the exact same prefix.
4421                         # In UCA, tab is the only character that can sort above LF
4422                         # so we strip both of them from the original prefix.
4423                         $prefix = strtr( $prefix, "\n\t", '  ' );
4424                         return "$prefix\n$unprefixed";
4425                 }
4426                 return $unprefixed;
4427         }
4428
4429         /**
4430          * Get the language in which the content of this page is written.
4431          * Defaults to $wgContLang, but in certain cases it can be e.g.
4432          * $wgLang (such as special pages, which are in the user language).
4433          *
4434          * @since 1.18
4435          * @return object Language
4436          */
4437         public function getPageLanguage() {
4438                 global $wgLang;
4439                 if ( $this->isSpecialPage() ) {
4440                         // special pages are in the user language
4441                         return $wgLang;
4442                 } elseif ( $this->isCssOrJsPage() ) {
4443                         // css/js should always be LTR and is, in fact, English
4444                         return wfGetLangObj( 'en' );
4445                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4446                         // Parse mediawiki messages with correct target language
4447                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4448                         return wfGetLangObj( $lang );
4449                 }
4450                 global $wgContLang;
4451                 // If nothing special, it should be in the wiki content language
4452                 $pageLang = $wgContLang;
4453                 // Hook at the end because we don't want to override the above stuff
4454                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4455                 return wfGetLangObj( $pageLang );
4456         }
4457 }