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|bool database row
 264          */
 265         public function loadFromRow( $row ) {
 266                 if ( $row ) { // page found
 267                         if ( isset( $row->page_id ) )
 268                                 $this->mArticleID = (int)$row->page_id;
 269                         if ( isset( $row->page_len ) )
 270                                 $this->mLength = (int)$row->page_len;
 271                         if ( isset( $row->page_is_redirect ) )
 272                                 $this->mRedirect = (bool)$row->page_is_redirect;
 273                         if ( isset( $row->page_latest ) )
 274                                 $this->mLatestID = (int)$row->page_latest;
 275                 } else { // page not found
 276                         $this->mArticleID = 0;
 277                         $this->mLength = 0;
 278                         $this->mRedirect = false;
 279                         $this->mLatestID = 0;
 280                 }
 281         }
 282
 283         /**
 284          * Create a new Title from a namespace index and a DB key.
 285          * It's assumed that $ns and $title are *valid*, for instance when
 286          * they came directly from the database or a special page name.
 287          * For convenience, spaces are converted to underscores so that
 288          * eg user_text fields can be used directly.
 289          *
 290          * @param $ns Int the namespace of the article
 291          * @param $title String the unprefixed database key form
 292          * @param $fragment String the link fragment (after the "#")
 293          * @param $interwiki String the interwiki prefix
 294          * @return Title the new object
 295          */
 296         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 297                 $t = new Title();
 298                 $t->mInterwiki = $interwiki;
 299                 $t->mFragment = $fragment;
 300                 $t->mNamespace = $ns = intval( $ns );
 301                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 302                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 303                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 304                 $t->mTextform = str_replace( '_', ' ', $title );
 305                 return $t;
 306         }
 307
 308         /**
 309          * Create a new Title from a namespace index and a DB key.
 310          * The parameters will be checked for validity, which is a bit slower
 311          * than makeTitle() but safer for user-provided data.
 312          *
 313          * @param $ns Int the namespace of the article
 314          * @param $title String database key form
 315          * @param $fragment String the link fragment (after the "#")
 316          * @param $interwiki String interwiki prefix
 317          * @return Title the new object, or NULL on an error
 318          */
 319         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 320                 if ( !MWNamespace::exists( $ns ) ) {
 321                         return null;
 322                 }
 323
 324                 $t = new Title();
 325                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 326                 if ( $t->secureAndSplit() ) {
 327                         return $t;
 328                 } else {
 329                         return null;
 330                 }
 331         }
 332
 333         /**
 334          * Create a new Title for the Main Page
 335          *
 336          * @return Title the new object
 337          */
 338         public static function newMainPage() {
 339                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 340                 // Don't give fatal errors if the message is broken
 341                 if ( !$title ) {
 342                         $title = Title::newFromText( 'Main Page' );
 343                 }
 344                 return $title;
 345         }
 346
 347         /**
 348          * Extract a redirect destination from a string and return the
 349          * Title, or null if the text doesn't contain a valid redirect
 350          * This will only return the very next target, useful for
 351          * the redirect table and other checks that don't need full recursion
 352          *
 353          * @param $text String: Text with possible redirect
 354          * @return Title: The corresponding Title
 355          */
 356         public static function newFromRedirect( $text ) {
 357                 return self::newFromRedirectInternal( $text );
 358         }
 359
 360         /**
 361          * Extract a redirect destination from a string and return the
 362          * Title, or null if the text doesn't contain a valid redirect
 363          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 364          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 365          *
 366          * @param $text String Text with possible redirect
 367          * @return Title
 368          */
 369         public static function newFromRedirectRecurse( $text ) {
 370                 $titles = self::newFromRedirectArray( $text );
 371                 return $titles ? array_pop( $titles ) : null;
 372         }
 373
 374         /**
 375          * Extract a redirect destination from a string and return an
 376          * array of Titles, or null if the text doesn't contain a valid redirect
 377          * The last element in the array is the final destination after all redirects
 378          * have been resolved (up to $wgMaxRedirects times)
 379          *
 380          * @param $text String Text with possible redirect
 381          * @return Array of Titles, with the destination last
 382          */
 383         public static function newFromRedirectArray( $text ) {
 384                 global $wgMaxRedirects;
 385                 $title = self::newFromRedirectInternal( $text );
 386                 if ( is_null( $title ) ) {
 387                         return null;
 388                 }
 389                 // recursive check to follow double redirects
 390                 $recurse = $wgMaxRedirects;
 391                 $titles = array( $title );
 392                 while ( --$recurse > 0 ) {
 393                         if ( $title->isRedirect() ) {
 394                                 $page = WikiPage::factory( $title );
 395                                 $newtitle = $page->getRedirectTarget();
 396                         } else {
 397                                 break;
 398                         }
 399                         // Redirects to some special pages are not permitted
 400                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 401                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 402                                 $title = $newtitle;
 403                                 $titles[] = $newtitle;
 404                         } else {
 405                                 break;
 406                         }
 407                 }
 408                 return $titles;
 409         }
 410
 411         /**
 412          * Really extract the redirect destination
 413          * Do not call this function directly, use one of the newFromRedirect* functions above
 414          *
 415          * @param $text String Text with possible redirect
 416          * @return Title
 417          */
 418         protected static function newFromRedirectInternal( $text ) {
 419                 global $wgMaxRedirects;
 420                 if ( $wgMaxRedirects < 1 ) {
 421                         //redirects are disabled, so quit early
 422                         return null;
 423                 }
 424                 $redir = MagicWord::get( 'redirect' );
 425                 $text = trim( $text );
 426                 if ( $redir->matchStartAndRemove( $text ) ) {
 427                         // Extract the first link and see if it's usable
 428                         // Ensure that it really does come directly after #REDIRECT
 429                         // Some older redirects included a colon, so don't freak about that!
 430                         $m = array();
 431                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 432                                 // Strip preceding colon used to "escape" categories, etc.
 433                                 // and URL-decode links
 434                                 if ( strpos( $m[1], '%' ) !== false ) {
 435                                         // Match behavior of inline link parsing here;
 436                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 437                                 }
 438                                 $title = Title::newFromText( $m[1] );
 439                                 // If the title is a redirect to bad special pages or is invalid, return null
 440                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 441                                         return null;
 442                                 }
 443                                 return $title;
 444                         }
 445                 }
 446                 return null;
 447         }
 448
 449         /**
 450          * Get the prefixed DB key associated with an ID
 451          *
 452          * @param $id Int the page_id of the article
 453          * @return Title an object representing the article, or NULL if no such article was found
 454          */
 455         public static function nameOf( $id ) {
 456                 $dbr = wfGetDB( DB_SLAVE );
 457
 458                 $s = $dbr->selectRow(
 459                         'page',
 460                         array( 'page_namespace', 'page_title' ),
 461                         array( 'page_id' => $id ),
 462                         __METHOD__
 463                 );
 464                 if ( $s === false ) {
 465                         return null;
 466                 }
 467
 468                 $n = self::makeName( $s->page_namespace, $s->page_title );
 469                 return $n;
 470         }
 471
 472         /**
 473          * Get a regex character class describing the legal characters in a link
 474          *
 475          * @return String the list of characters, not delimited
 476          */
 477         public static function legalChars() {
 478                 global $wgLegalTitleChars;
 479                 return $wgLegalTitleChars;
 480         }
 481
 482         /**
 483          * Returns a simple regex that will match on characters and sequences invalid in titles.
 484          * Note that this doesn't pick up many things that could be wrong with titles, but that
 485          * replacing this regex with something valid will make many titles valid.
 486          *
 487          * @return String regex string
 488          */
 489         static function getTitleInvalidRegex() {
 490                 static $rxTc = false;
 491                 if ( !$rxTc ) {
 492                         # Matching titles will be held as illegal.
 493                         $rxTc = '/' .
 494                                 # Any character not allowed is forbidden...
 495                                 '[^' . self::legalChars() . ']' .
 496                                 # URL percent encoding sequences interfere with the ability
 497                                 # to round-trip titles -- you can't link to them consistently.
 498                                 '|%[0-9A-Fa-f]{2}' .
 499                                 # XML/HTML character references produce similar issues.
 500                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 501                                 '|&#[0-9]+;' .
 502                                 '|&#x[0-9A-Fa-f]+;' .
 503                                 '/S';
 504                 }
 505
 506                 return $rxTc;
 507         }
 508
 509         /**
 510          * Get a string representation of a title suitable for
 511          * including in a search index
 512          *
 513          * @param $ns Int a namespace index
 514          * @param $title String text-form main part
 515          * @return String a stripped-down title string ready for the search index
 516          */
 517         public static function indexTitle( $ns, $title ) {
 518                 global $wgContLang;
 519
 520                 $lc = SearchEngine::legalSearchChars() . '&#;';
 521                 $t = $wgContLang->normalizeForSearch( $title );
 522                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 523                 $t = $wgContLang->lc( $t );
 524
 525                 # Handle 's, s'
 526                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 527                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 528
 529                 $t = preg_replace( "/\\s+/", ' ', $t );
 530
 531                 if ( $ns == NS_FILE ) {
 532                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 533                 }
 534                 return trim( $t );
 535         }
 536
 537         /**
 538          * Make a prefixed DB key from a DB key and a namespace index
 539          *
 540          * @param $ns Int numerical representation of the namespace
 541          * @param $title String the DB key form the title
 542          * @param $fragment String The link fragment (after the "#")
 543          * @param $interwiki String The interwiki prefix
 544          * @return String the prefixed form of the title
 545          */
 546         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 547                 global $wgContLang;
 548
 549                 $namespace = $wgContLang->getNsText( $ns );
 550                 $name = $namespace == '' ? $title : "$namespace:$title";
 551                 if ( strval( $interwiki ) != '' ) {
 552                         $name = "$interwiki:$name";
 553                 }
 554                 if ( strval( $fragment ) != '' ) {
 555                         $name .= '#' . $fragment;
 556                 }
 557                 return $name;
 558         }
 559
 560         /**
 561          * Escape a text fragment, say from a link, for a URL
 562          *
 563          * @param $fragment string containing a URL or link fragment (after the "#")
 564          * @return String: escaped string
 565          */
 566         static function escapeFragmentForURL( $fragment ) {
 567                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 568                 # fragments appear not to work in IE (at least up to 7) or in at least
 569                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 570                 # to care if they aren't encoded.
 571                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 572         }
 573
 574         /**
 575          * Callback for usort() to do title sorts by (namespace, title)
 576          *
 577          * @param $a Title
 578          * @param $b Title
 579          *
 580          * @return Integer: result of string comparison, or namespace comparison
 581          */
 582         public static function compare( $a, $b ) {
 583                 if ( $a->getNamespace() == $b->getNamespace() ) {
 584                         return strcmp( $a->getText(), $b->getText() );
 585                 } else {
 586                         return $a->getNamespace() - $b->getNamespace();
 587                 }
 588         }
 589
 590         /**
 591          * Determine whether the object refers to a page within
 592          * this project.
 593          *
 594          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 595          */
 596         public function isLocal() {
 597                 if ( $this->mInterwiki != '' ) {
 598                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 599                 } else {
 600                         return true;
 601                 }
 602         }
 603
 604         /**
 605          * Is this Title interwiki?
 606          *
 607          * @return Bool
 608          */
 609         public function isExternal() {
 610                 return ( $this->mInterwiki != '' );
 611         }
 612
 613         /**
 614          * Get the interwiki prefix (or null string)
 615          *
 616          * @return String Interwiki prefix
 617          */
 618         public function getInterwiki() {
 619                 return $this->mInterwiki;
 620         }
 621
 622         /**
 623          * Determine whether the object refers to a page within
 624          * this project and is transcludable.
 625          *
 626          * @return Bool TRUE if this is transcludable
 627          */
 628         public function isTrans() {
 629                 if ( $this->mInterwiki == '' ) {
 630                         return false;
 631                 }
 632
 633                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 634         }
 635
 636         /**
 637          * Returns the DB name of the distant wiki which owns the object.
 638          *
 639          * @return String the DB name
 640          */
 641         public function getTransWikiID() {
 642                 if ( $this->mInterwiki == '' ) {
 643                         return false;
 644                 }
 645
 646                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 647         }
 648
 649         /**
 650          * Get the text form (spaces not underscores) of the main part
 651          *
 652          * @return String Main part of the title
 653          */
 654         public function getText() {
 655                 return $this->mTextform;
 656         }
 657
 658         /**
 659          * Get the URL-encoded form of the main part
 660          *
 661          * @return String Main part of the title, URL-encoded
 662          */
 663         public function getPartialURL() {
 664                 return $this->mUrlform;
 665         }
 666
 667         /**
 668          * Get the main part with underscores
 669          *
 670          * @return String: Main part of the title, with underscores
 671          */
 672         public function getDBkey() {
 673                 return $this->mDbkeyform;
 674         }
 675
 676         /**
 677          * Get the DB key with the initial letter case as specified by the user
 678          *
 679          * @return String DB key
 680          */
 681         function getUserCaseDBKey() {
 682                 return $this->mUserCaseDBKey;
 683         }
 684
 685         /**
 686          * Get the namespace index, i.e. one of the NS_xxxx constants.
 687          *
 688          * @return Integer: Namespace index
 689          */
 690         public function getNamespace() {
 691                 return $this->mNamespace;
 692         }
 693
 694         /**
 695          * Get the namespace text
 696          *
 697          * @return String: Namespace text
 698          */
 699         public function getNsText() {
 700                 global $wgContLang;
 701
 702                 if ( $this->mInterwiki != '' ) {
 703                         // This probably shouldn't even happen. ohh man, oh yuck.
 704                         // But for interwiki transclusion it sometimes does.
 705                         // Shit. Shit shit shit.
 706                         //
 707                         // Use the canonical namespaces if possible to try to
 708                         // resolve a foreign namespace.
 709                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 710                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 711                         }
 712                 }
 713
 714                 if ( $wgContLang->needsGenderDistinction() &&
 715                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 716                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 717                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 718                 }
 719
 720                 return $wgContLang->getNsText( $this->mNamespace );
 721         }
 722
 723         /**
 724          * Get the namespace text of the subject (rather than talk) page
 725          *
 726          * @return String Namespace text
 727          */
 728         public function getSubjectNsText() {
 729                 global $wgContLang;
 730                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 731         }
 732
 733         /**
 734          * Get the namespace text of the talk page
 735          *
 736          * @return String Namespace text
 737          */
 738         public function getTalkNsText() {
 739                 global $wgContLang;
 740                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 741         }
 742
 743         /**
 744          * Could this title have a corresponding talk page?
 745          *
 746          * @return Bool TRUE or FALSE
 747          */
 748         public function canTalk() {
 749                 return( MWNamespace::canTalk( $this->mNamespace ) );
 750         }
 751
 752         /**
 753          * Is this in a namespace that allows actual pages?
 754          *
 755          * @return Bool
 756          * @internal note -- uses hardcoded namespace index instead of constants
 757          */
 758         public function canExist() {
 759                 return $this->mNamespace >= NS_MAIN;
 760         }
 761
 762         /**
 763          * Can this title be added to a user's watchlist?
 764          *
 765          * @return Bool TRUE or FALSE
 766          */
 767         public function isWatchable() {
 768                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 769         }
 770
 771         /**
 772          * Returns true if this is a special page.
 773          *
 774          * @return boolean
 775          */
 776         public function isSpecialPage() {
 777                 return $this->getNamespace() == NS_SPECIAL;
 778         }
 779
 780         /**
 781          * Returns true if this title resolves to the named special page
 782          *
 783          * @param $name String The special page name
 784          * @return boolean
 785          */
 786         public function isSpecial( $name ) {
 787                 if ( $this->isSpecialPage() ) {
 788                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 789                         if ( $name == $thisName ) {
 790                                 return true;
 791                         }
 792                 }
 793                 return false;
 794         }
 795
 796         /**
 797          * If the Title refers to a special page alias which is not the local default, resolve
 798          * the alias, and localise the name as necessary.  Otherwise, return $this
 799          *
 800          * @return Title
 801          */
 802         public function fixSpecialName() {
 803                 if ( $this->isSpecialPage() ) {
 804                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 805                         if ( $canonicalName ) {
 806                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 807                                 if ( $localName != $this->mDbkeyform ) {
 808                                         return Title::makeTitle( NS_SPECIAL, $localName );
 809                                 }
 810                         }
 811                 }
 812                 return $this;
 813         }
 814
 815         /**
 816          * Returns true if the title is inside the specified namespace.
 817          *
 818          * Please make use of this instead of comparing to getNamespace()
 819          * This function is much more resistant to changes we may make
 820          * to namespaces than code that makes direct comparisons.
 821          * @param $ns int The namespace
 822          * @return bool
 823          * @since 1.19
 824          */
 825         public function inNamespace( $ns ) {
 826                 return MWNamespace::equals( $this->getNamespace(), $ns );
 827         }
 828
 829         /**
 830          * Returns true if the title is inside one of the specified namespaces.
 831          *
 832          * @param ...$namespaces The namespaces to check for
 833          * @return bool
 834          * @since 1.19
 835          */
 836         public function inNamespaces( /* ... */ ) {
 837                 $namespaces = func_get_args();
 838                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 839                         $namespaces = $namespaces[0];
 840                 }
 841
 842                 foreach ( $namespaces as $ns ) {
 843                         if ( $this->inNamespace( $ns ) ) {
 844                                 return true;
 845                         }
 846                 }
 847
 848                 return false;
 849         }
 850
 851         /**
 852          * Returns true if the title has the same subject namespace as the
 853          * namespace specified.
 854          * For example this method will take NS_USER and return true if namespace
 855          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 856          * as their subject namespace.
 857          *
 858          * This is MUCH simpler than individually testing for equivilance
 859          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 860          * @since 1.19
 861          * @return bool
 862          */
 863         public function hasSubjectNamespace( $ns ) {
 864                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 865         }
 866
 867         /**
 868          * Is this Title in a namespace which contains content?
 869          * In other words, is this a content page, for the purposes of calculating
 870          * statistics, etc?
 871          *
 872          * @return Boolean
 873          */
 874         public function isContentPage() {
 875                 return MWNamespace::isContent( $this->getNamespace() );
 876         }
 877
 878         /**
 879          * Would anybody with sufficient privileges be able to move this page?
 880          * Some pages just aren't movable.
 881          *
 882          * @return Bool TRUE or FALSE
 883          */
 884         public function isMovable() {
 885                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 886                         // Interwiki title or immovable namespace. Hooks don't get to override here
 887                         return false;
 888                 }
 889
 890                 $result = true;
 891                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 892                 return $result;
 893         }
 894
 895         /**
 896          * Is this the mainpage?
 897          * @note Title::newFromText seams to be sufficiently optimized by the title
 898          * cache that we don't need to over-optimize by doing direct comparisons and
 899          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 900          * ends up reporting something differently than $title->isMainPage();
 901          *
 902          * @since 1.18
 903          * @return Bool
 904          */
 905         public function isMainPage() {
 906                 return $this->equals( Title::newMainPage() );
 907         }
 908
 909         /**
 910          * Is this a subpage?
 911          *
 912          * @return Bool
 913          */
 914         public function isSubpage() {
 915                 return MWNamespace::hasSubpages( $this->mNamespace )
 916                         ? strpos( $this->getText(), '/' ) !== false
 917                         : false;
 918         }
 919
 920         /**
 921          * Is this a conversion table for the LanguageConverter?
 922          *
 923          * @return Bool
 924          */
 925         public function isConversionTable() {
 926                 return $this->getNamespace() == NS_MEDIAWIKI &&
 927                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 928         }
 929
 930         /**
 931          * Does that page contain wikitext, or it is JS, CSS or whatever?
 932          *
 933          * @return Bool
 934          */
 935         public function isWikitextPage() {
 936                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
 937                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
 938                 return $retval;
 939         }
 940
 941         /**
 942          * Could this page contain custom CSS or JavaScript, based
 943          * on the title?
 944          *
 945          * @return Bool
 946          */
 947         public function isCssOrJsPage() {
 948                 $retval = $this->mNamespace == NS_MEDIAWIKI
 949                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
 950                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
 951                 return $retval;
 952         }
 953
 954         /**
 955          * Is this a .css or .js subpage of a user page?
 956          * @return Bool
 957          */
 958         public function isCssJsSubpage() {
 959                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
 960         }
 961
 962         /**
 963          * Trim down a .css or .js subpage title to get the corresponding skin name
 964          *
 965          * @return string containing skin name from .css or .js subpage title
 966          */
 967         public function getSkinFromCssJsSubpage() {
 968                 $subpage = explode( '/', $this->mTextform );
 969                 $subpage = $subpage[ count( $subpage ) - 1 ];
 970                 $lastdot = strrpos( $subpage, '.' );
 971                 if ( $lastdot === false )
 972                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 973                 return substr( $subpage, 0, $lastdot );
 974         }
 975
 976         /**
 977          * Is this a .css subpage of a user page?
 978          *
 979          * @return Bool
 980          */
 981         public function isCssSubpage() {
 982                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
 983         }
 984
 985         /**
 986          * Is this a .js subpage of a user page?
 987          *
 988          * @return Bool
 989          */
 990         public function isJsSubpage() {
 991                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
 992         }
 993
 994         /**
 995          * Is this a talk page of some sort?
 996          *
 997          * @return Bool
 998          */
 999         public function isTalkPage() {
1000                 return MWNamespace::isTalk( $this->getNamespace() );
1001         }
1002
1003         /**
1004          * Get a Title object associated with the talk page of this article
1005          *
1006          * @return Title the object for the talk page
1007          */
1008         public function getTalkPage() {
1009                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1010         }
1011
1012         /**
1013          * Get a title object associated with the subject page of this
1014          * talk page
1015          *
1016          * @return Title the object for the subject page
1017          */
1018         public function getSubjectPage() {
1019                 // Is this the same title?
1020                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1021                 if ( $this->getNamespace() == $subjectNS ) {
1022                         return $this;
1023                 }
1024                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1025         }
1026
1027         /**
1028          * Get the default namespace index, for when there is no namespace
1029          *
1030          * @return Int Default namespace index
1031          */
1032         public function getDefaultNamespace() {
1033                 return $this->mDefaultNamespace;
1034         }
1035
1036         /**
1037          * Get title for search index
1038          *
1039          * @return String a stripped-down title string ready for the
1040          *  search index
1041          */
1042         public function getIndexTitle() {
1043                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1044         }
1045
1046         /**
1047          * Get the Title fragment (i.e.\ the bit after the #) in text form
1048          *
1049          * @return String Title fragment
1050          */
1051         public function getFragment() {
1052                 return $this->mFragment;
1053         }
1054
1055         /**
1056          * Get the fragment in URL form, including the "#" character if there is one
1057          * @return String Fragment in URL form
1058          */
1059         public function getFragmentForURL() {
1060                 if ( $this->mFragment == '' ) {
1061                         return '';
1062                 } else {
1063                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1064                 }
1065         }
1066
1067         /**
1068          * Set the fragment for this title. Removes the first character from the
1069          * specified fragment before setting, so it assumes you're passing it with
1070          * an initial "#".
1071          *
1072          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1073          * Still in active use privately.
1074          *
1075          * @param $fragment String text
1076          */
1077         public function setFragment( $fragment ) {
1078                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1079         }
1080
1081         /**
1082          * Prefix some arbitrary text with the namespace or interwiki prefix
1083          * of this object
1084          *
1085          * @param $name String the text
1086          * @return String the prefixed text
1087          * @private
1088          */
1089         private function prefix( $name ) {
1090                 $p = '';
1091                 if ( $this->mInterwiki != '' ) {
1092                         $p = $this->mInterwiki . ':';
1093                 }
1094
1095                 if ( 0 != $this->mNamespace ) {
1096                         $p .= $this->getNsText() . ':';
1097                 }
1098                 return $p . $name;
1099         }
1100
1101         /**
1102          * Get the prefixed database key form
1103          *
1104          * @return String the prefixed title, with underscores and
1105          *  any interwiki and namespace prefixes
1106          */
1107         public function getPrefixedDBkey() {
1108                 $s = $this->prefix( $this->mDbkeyform );
1109                 $s = str_replace( ' ', '_', $s );
1110                 return $s;
1111         }
1112
1113         /**
1114          * Get the prefixed title with spaces.
1115          * This is the form usually used for display
1116          *
1117          * @return String the prefixed title, with spaces
1118          */
1119         public function getPrefixedText() {
1120                 // @todo FIXME: Bad usage of empty() ?
1121                 if ( empty( $this->mPrefixedText ) ) {
1122                         $s = $this->prefix( $this->mTextform );
1123                         $s = str_replace( '_', ' ', $s );
1124                         $this->mPrefixedText = $s;
1125                 }
1126                 return $this->mPrefixedText;
1127         }
1128
1129         /**
1130          * Return a string representation of this title
1131          *
1132          * @return String representation of this title
1133          */
1134         public function __toString() {
1135                 return $this->getPrefixedText();
1136         }
1137
1138         /**
1139          * Get the prefixed title with spaces, plus any fragment
1140          * (part beginning with '#')
1141          *
1142          * @return String the prefixed title, with spaces and the fragment, including '#'
1143          */
1144         public function getFullText() {
1145                 $text = $this->getPrefixedText();
1146                 if ( $this->mFragment != '' ) {
1147                         $text .= '#' . $this->mFragment;
1148                 }
1149                 return $text;
1150         }
1151
1152         /**
1153          * Get the base page name, i.e. the leftmost part before any slashes
1154          *
1155          * @return String Base name
1156          */
1157         public function getBaseText() {
1158                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1159                         return $this->getText();
1160                 }
1161
1162                 $parts = explode( '/', $this->getText() );
1163                 # Don't discard the real title if there's no subpage involved
1164                 if ( count( $parts ) > 1 ) {
1165                         unset( $parts[count( $parts ) - 1] );
1166                 }
1167                 return implode( '/', $parts );
1168         }
1169
1170         /**
1171          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1172          *
1173          * @return String Subpage name
1174          */
1175         public function getSubpageText() {
1176                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1177                         return( $this->mTextform );
1178                 }
1179                 $parts = explode( '/', $this->mTextform );
1180                 return( $parts[count( $parts ) - 1] );
1181         }
1182
1183         /**
1184          * Get the HTML-escaped displayable text form.
1185          * Used for the title field in <a> tags.
1186          *
1187          * @return String the text, including any prefixes
1188          */
1189         public function getEscapedText() {
1190                 wfDeprecated( __METHOD__, '1.19' );
1191                 return htmlspecialchars( $this->getPrefixedText() );
1192         }
1193
1194         /**
1195          * Get a URL-encoded form of the subpage text
1196          *
1197          * @return String URL-encoded subpage name
1198          */
1199         public function getSubpageUrlForm() {
1200                 $text = $this->getSubpageText();
1201                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1202                 return( $text );
1203         }
1204
1205         /**
1206          * Get a URL-encoded title (not an actual URL) including interwiki
1207          *
1208          * @return String the URL-encoded form
1209          */
1210         public function getPrefixedURL() {
1211                 $s = $this->prefix( $this->mDbkeyform );
1212                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1213                 return $s;
1214         }
1215
1216         /**
1217          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1218          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1219          * second argument named variant. This was deprecated in favor
1220          * of passing an array of option with a "variant" key
1221          * Once $query2 is removed for good, this helper can be dropped
1222          * andthe wfArrayToCGI moved to getLocalURL();
1223          *
1224          * @since 1.19 (r105919)
1225          * @return String
1226          */
1227         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1228                 if( $query2 !== false ) {
1229                         wfDeprecated( "Title::get{Canonical,Full,Link,Local} method called with a second parameter is deprecated. Add your parameter to an array passed as the first parameter.", "1.19" );
1230                 }
1231                 if ( is_array( $query ) ) {
1232                         $query = wfArrayToCGI( $query );
1233                 }
1234                 if ( $query2 ) {
1235                         if ( is_string( $query2 ) ) {
1236                                 // $query2 is a string, we will consider this to be
1237                                 // a deprecated $variant argument and add it to the query
1238                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1239                         } else {
1240                                 $query2 = wfArrayToCGI( $query2 );
1241                         }
1242                         // If we have $query content add a & to it first
1243                         if ( $query ) {
1244                                 $query .= '&';
1245                         }
1246                         // Now append the queries together
1247                         $query .= $query2;
1248                 }
1249                 return $query;
1250         }
1251
1252         /**
1253          * Get a real URL referring to this title, with interwiki link and
1254          * fragment
1255          *
1256          * See getLocalURL for the arguments.
1257          *
1258          * @see self::getLocalURL
1259          * @return String the URL
1260          */
1261         public function getFullURL( $query = '', $query2 = false ) {
1262                 $query = self::fixUrlQueryArgs( $query, $query2 );
1263
1264                 # Hand off all the decisions on urls to getLocalURL
1265                 $url = $this->getLocalURL( $query );
1266
1267                 # Expand the url to make it a full url. Note that getLocalURL has the
1268                 # potential to output full urls for a variety of reasons, so we use
1269                 # wfExpandUrl instead of simply prepending $wgServer
1270                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1271
1272                 # Finally, add the fragment.
1273                 $url .= $this->getFragmentForURL();
1274
1275                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1276                 return $url;
1277         }
1278
1279         /**
1280          * Get a URL with no fragment or server name.  If this page is generated
1281          * with action=render, $wgServer is prepended.
1282          *
1283
1284          * @param $query string|array an optional query string,
1285          *   not used for interwiki     links. Can be specified as an associative array as well,
1286          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1287          *   Some query patterns will trigger various shorturl path replacements.
1288          * @param $query2 Mixed: An optional secondary query array. This one MUST
1289          *   be an array. If a string is passed it will be interpreted as a deprecated
1290          *   variant argument and urlencoded into a variant= argument.
1291          *   This second query argument will be added to the $query
1292          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1293          *   pair in the first parameter array instead.
1294          *
1295          * @return String the URL
1296          */
1297         public function getLocalURL( $query = '', $query2 = false ) {
1298                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1299
1300                 $query = self::fixUrlQueryArgs( $query, $query2 );
1301
1302                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1303                 if ( $interwiki ) {
1304                         $namespace = $this->getNsText();
1305                         if ( $namespace != '' ) {
1306                                 # Can this actually happen? Interwikis shouldn't be parsed.
1307                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1308                                 $namespace .= ':';
1309                         }
1310                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1311                         $url = wfAppendQuery( $url, $query );
1312                 } else {
1313                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1314                         if ( $query == '' ) {
1315                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1316                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1317                         } else {
1318                                 global $wgVariantArticlePath, $wgActionPaths;
1319                                 $url = false;
1320                                 $matches = array();
1321
1322                                 if ( !empty( $wgActionPaths ) &&
1323                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1324                                 {
1325                                         $action = urldecode( $matches[2] );
1326                                         if ( isset( $wgActionPaths[$action] ) ) {
1327                                                 $query = $matches[1];
1328                                                 if ( isset( $matches[4] ) ) {
1329                                                         $query .= $matches[4];
1330                                                 }
1331                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1332                                                 if ( $query != '' ) {
1333                                                         $url = wfAppendQuery( $url, $query );
1334                                                 }
1335                                         }
1336                                 }
1337
1338                                 if ( $url === false &&
1339                                         $wgVariantArticlePath &&
1340                                         $this->getPageLanguage()->hasVariants() &&
1341                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1342                                 {
1343                                         $variant = urldecode( $matches[1] );
1344                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1345                                                 // Only do the variant replacement if the given variant is a valid
1346                                                 // variant for the page's language.
1347                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1348                                                 $url = str_replace( '$1', $dbkey, $url );
1349                                         }
1350                                 }
1351
1352                                 if ( $url === false ) {
1353                                         if ( $query == '-' ) {
1354                                                 $query = '';
1355                                         }
1356                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1357                                 }
1358                         }
1359
1360                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1361
1362                         // @todo FIXME: This causes breakage in various places when we
1363                         // actually expected a local URL and end up with dupe prefixes.
1364                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1365                                 $url = $wgServer . $url;
1366                         }
1367                 }
1368                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1369                 return $url;
1370         }
1371
1372         /**
1373          * Get a URL that's the simplest URL that will be valid to link, locally,
1374          * to the current Title.  It includes the fragment, but does not include
1375          * the server unless action=render is used (or the link is external).  If
1376          * there's a fragment but the prefixed text is empty, we just return a link
1377          * to the fragment.
1378          *
1379          * The result obviously should not be URL-escaped, but does need to be
1380          * HTML-escaped if it's being output in HTML.
1381          *
1382          * See getLocalURL for the arguments.
1383          *
1384          * @see self::getLocalURL
1385          * @return String the URL
1386          */
1387         public function getLinkURL( $query = '', $query2 = false ) {
1388                 wfProfileIn( __METHOD__ );
1389                 if ( $this->isExternal() ) {
1390                         $ret = $this->getFullURL( $query, $query2 );
1391                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1392                         $ret = $this->getFragmentForURL();
1393                 } else {
1394                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1395                 }
1396                 wfProfileOut( __METHOD__ );
1397                 return $ret;
1398         }
1399
1400         /**
1401          * Get an HTML-escaped version of the URL form, suitable for
1402          * using in a link, without a server name or fragment
1403          *
1404          * See getLocalURL for the arguments.
1405          *
1406          * @see self::getLocalURL
1407          * @return String the URL
1408          */
1409         public function escapeLocalURL( $query = '', $query2 = false ) {
1410                 wfDeprecated( __METHOD__, '1.19' );
1411                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1412         }
1413
1414         /**
1415          * Get an HTML-escaped version of the URL form, suitable for
1416          * using in a link, including the server name and fragment
1417          *
1418          * See getLocalURL for the arguments.
1419          *
1420          * @see self::getLocalURL
1421          * @return String the URL
1422          */
1423         public function escapeFullURL( $query = '', $query2 = false ) {
1424                 wfDeprecated( __METHOD__, '1.19' );
1425                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1426         }
1427
1428         /**
1429          * Get the URL form for an internal link.
1430          * - Used in various Squid-related code, in case we have a different
1431          * internal hostname for the server from the exposed one.
1432          *
1433          * This uses $wgInternalServer to qualify the path, or $wgServer
1434          * if $wgInternalServer is not set. If the server variable used is
1435          * protocol-relative, the URL will be expanded to http://
1436          *
1437          * See getLocalURL for the arguments.
1438          *
1439          * @see self::getLocalURL
1440          * @return String the URL
1441          */
1442         public function getInternalURL( $query = '', $query2 = false ) {
1443                 global $wgInternalServer, $wgServer;
1444                 $query = self::fixUrlQueryArgs( $query, $query2 );
1445                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1446                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1447                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1448                 return $url;
1449         }
1450
1451         /**
1452          * Get the URL for a canonical link, for use in things like IRC and
1453          * e-mail notifications. Uses $wgCanonicalServer and the
1454          * GetCanonicalURL hook.
1455          *
1456          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1457          *
1458          * See getLocalURL for the arguments.
1459          *
1460          * @see self::getLocalURL
1461          * @return string The URL
1462          * @since 1.18
1463          */
1464         public function getCanonicalURL( $query = '', $query2 = false ) {
1465                 $query = self::fixUrlQueryArgs( $query, $query2 );
1466                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1467                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1468                 return $url;
1469         }
1470
1471         /**
1472          * HTML-escaped version of getCanonicalURL()
1473          *
1474          * See getLocalURL for the arguments.
1475          *
1476          * @see self::getLocalURL
1477          * @since 1.18
1478          * @return string
1479          */
1480         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1481                 wfDeprecated( __METHOD__, '1.19' );
1482                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1483         }
1484
1485         /**
1486          * Get the edit URL for this Title
1487          *
1488          * @return String the URL, or a null string if this is an
1489          *  interwiki link
1490          */
1491         public function getEditURL() {
1492                 if ( $this->mInterwiki != '' ) {
1493                         return '';
1494                 }
1495                 $s = $this->getLocalURL( 'action=edit' );
1496
1497                 return $s;
1498         }
1499
1500         /**
1501          * Is $wgUser watching this page?
1502          *
1503          * @return Bool
1504          */
1505         public function userIsWatching() {
1506                 global $wgUser;
1507
1508                 if ( is_null( $this->mWatched ) ) {
1509                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1510                                 $this->mWatched = false;
1511                         } else {
1512                                 $this->mWatched = $wgUser->isWatched( $this );
1513                         }
1514                 }
1515                 return $this->mWatched;
1516         }
1517
1518         /**
1519          * Can $wgUser read this page?
1520          *
1521          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1522          * @return Bool
1523          * @todo fold these checks into userCan()
1524          */
1525         public function userCanRead() {
1526                 wfDeprecated( __METHOD__, '1.19' );
1527                 return $this->userCan( 'read' );
1528         }
1529
1530         /**
1531          * Can $user perform $action on this page?
1532          * This skips potentially expensive cascading permission checks
1533          * as well as avoids expensive error formatting
1534          *
1535          * Suitable for use for nonessential UI controls in common cases, but
1536          * _not_ for functional access control.
1537          *
1538          * May provide false positives, but should never provide a false negative.
1539          *
1540          * @param $action String action that permission needs to be checked for
1541          * @param $user User to check (since 1.19); $wgUser will be used if not
1542          *              provided.
1543          * @return Bool
1544          */
1545         public function quickUserCan( $action, $user = null ) {
1546                 return $this->userCan( $action, $user, false );
1547         }
1548
1549         /**
1550          * Can $user perform $action on this page?
1551          *
1552          * @param $action String action that permission needs to be checked for
1553          * @param $user User to check (since 1.19); $wgUser will be used if not
1554          *   provided.
1555          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1556          *   unnecessary queries.
1557          * @return Bool
1558          */
1559         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1560                 if ( !$user instanceof User ) {
1561                         global $wgUser;
1562                         $user = $wgUser;
1563                 }
1564                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1565         }
1566
1567         /**
1568          * Can $user perform $action on this page?
1569          *
1570          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1571          *
1572          * @param $action String action that permission needs to be checked for
1573          * @param $user User to check
1574          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1575          *   queries by skipping checks for cascading protections and user blocks.
1576          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1577          *   whose corresponding errors may be ignored.
1578          * @return Array of arguments to wfMsg to explain permissions problems.
1579          */
1580         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1581                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1582
1583                 // Remove the errors being ignored.
1584                 foreach ( $errors as $index => $error ) {
1585                         $error_key = is_array( $error ) ? $error[0] : $error;
1586
1587                         if ( in_array( $error_key, $ignoreErrors ) ) {
1588                                 unset( $errors[$index] );
1589                         }
1590                 }
1591
1592                 return $errors;
1593         }
1594
1595         /**
1596          * Permissions checks that fail most often, and which are easiest to test.
1597          *
1598          * @param $action String the action to check
1599          * @param $user User user to check
1600          * @param $errors Array list of current errors
1601          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1602          * @param $short Boolean short circuit on first error
1603          *
1604          * @return Array list of errors
1605          */
1606         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1607                 if ( $action == 'create' ) {
1608                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1609                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1610                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1611                         }
1612                 } elseif ( $action == 'move' ) {
1613                         if ( !$user->isAllowed( 'move-rootuserpages' )
1614                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1615                                 // Show user page-specific message only if the user can move other pages
1616                                 $errors[] = array( 'cant-move-user-page' );
1617                         }
1618
1619                         // Check if user is allowed to move files if it's a file
1620                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1621                                 $errors[] = array( 'movenotallowedfile' );
1622                         }
1623
1624                         if ( !$user->isAllowed( 'move' ) ) {
1625                                 // User can't move anything
1626                                 global $wgGroupPermissions;
1627                                 $userCanMove = false;
1628                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1629                                         $userCanMove = $wgGroupPermissions['user']['move'];
1630                                 }
1631                                 $autoconfirmedCanMove = false;
1632                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1633                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1634                                 }
1635                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1636                                         // custom message if logged-in users without any special rights can move
1637                                         $errors[] = array( 'movenologintext' );
1638                                 } else {
1639                                         $errors[] = array( 'movenotallowed' );
1640                                 }
1641                         }
1642                 } elseif ( $action == 'move-target' ) {
1643                         if ( !$user->isAllowed( 'move' ) ) {
1644                                 // User can't move anything
1645                                 $errors[] = array( 'movenotallowed' );
1646                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1647                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1648                                 // Show user page-specific message only if the user can move other pages
1649                                 $errors[] = array( 'cant-move-to-user-page' );
1650                         }
1651                 } elseif ( !$user->isAllowed( $action ) ) {
1652                         $errors[] = $this->missingPermissionError( $action, $short );
1653                 }
1654
1655                 return $errors;
1656         }
1657
1658         /**
1659          * Add the resulting error code to the errors array
1660          *
1661          * @param $errors Array list of current errors
1662          * @param $result Mixed result of errors
1663          *
1664          * @return Array list of errors
1665          */
1666         private function resultToError( $errors, $result ) {
1667                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1668                         // A single array representing an error
1669                         $errors[] = $result;
1670                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1671                         // A nested array representing multiple errors
1672                         $errors = array_merge( $errors, $result );
1673                 } elseif ( $result !== '' && is_string( $result ) ) {
1674                         // A string representing a message-id
1675                         $errors[] = array( $result );
1676                 } elseif ( $result === false ) {
1677                         // a generic "We don't want them to do that"
1678                         $errors[] = array( 'badaccess-group0' );
1679                 }
1680                 return $errors;
1681         }
1682
1683         /**
1684          * Check various permission hooks
1685          *
1686          * @param $action String the action to check
1687          * @param $user User user to check
1688          * @param $errors Array list of current errors
1689          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1690          * @param $short Boolean short circuit on first error
1691          *
1692          * @return Array list of errors
1693          */
1694         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1695                 // Use getUserPermissionsErrors instead
1696                 $result = '';
1697                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1698                         return $result ? array() : array( array( 'badaccess-group0' ) );
1699                 }
1700                 // Check getUserPermissionsErrors hook
1701                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1702                         $errors = $this->resultToError( $errors, $result );
1703                 }
1704                 // Check getUserPermissionsErrorsExpensive hook
1705                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1706                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1707                         $errors = $this->resultToError( $errors, $result );
1708                 }
1709
1710                 return $errors;
1711         }
1712
1713         /**
1714          * Check permissions on special pages & namespaces
1715          *
1716          * @param $action String the action to check
1717          * @param $user User user to check
1718          * @param $errors Array list of current errors
1719          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1720          * @param $short Boolean short circuit on first error
1721          *
1722          * @return Array list of errors
1723          */
1724         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1725                 # Only 'createaccount' and 'execute' can be performed on
1726                 # special pages, which don't actually exist in the DB.
1727                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1728                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1729                         $errors[] = array( 'ns-specialprotected' );
1730                 }
1731
1732                 # Check $wgNamespaceProtection for restricted namespaces
1733                 if ( $this->isNamespaceProtected( $user ) ) {
1734                         $ns = $this->mNamespace == NS_MAIN ?
1735                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1736                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1737                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1738                 }
1739
1740                 return $errors;
1741         }
1742
1743         /**
1744          * Check CSS/JS sub-page permissions
1745          *
1746          * @param $action String the action to check
1747          * @param $user User user to check
1748          * @param $errors Array list of current errors
1749          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1750          * @param $short Boolean short circuit on first error
1751          *
1752          * @return Array list of errors
1753          */
1754         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1755                 # Protect css/js subpages of user pages
1756                 # XXX: this might be better using restrictions
1757                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1758                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1759                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1760                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1761                                 $errors[] = array( 'customcssprotected' );
1762                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1763                                 $errors[] = array( 'customjsprotected' );
1764                         }
1765                 }
1766
1767                 return $errors;
1768         }
1769
1770         /**
1771          * Check against page_restrictions table requirements on this
1772          * page. The user must possess all required rights for this
1773          * action.
1774          *
1775          * @param $action String the action to check
1776          * @param $user User user to check
1777          * @param $errors Array list of current errors
1778          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1779          * @param $short Boolean short circuit on first error
1780          *
1781          * @return Array list of errors
1782          */
1783         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1784                 foreach ( $this->getRestrictions( $action ) as $right ) {
1785                         // Backwards compatibility, rewrite sysop -> protect
1786                         if ( $right == 'sysop' ) {
1787                                 $right = 'protect';
1788                         }
1789                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1790                                 // Users with 'editprotected' permission can edit protected pages
1791                                 // without cascading option turned on.
1792                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1793                                         || $this->mCascadeRestriction )
1794                                 {
1795                                         $errors[] = array( 'protectedpagetext', $right );
1796                                 }
1797                         }
1798                 }
1799
1800                 return $errors;
1801         }
1802
1803         /**
1804          * Check restrictions on cascading pages.
1805          *
1806          * @param $action String the action to check
1807          * @param $user User to check
1808          * @param $errors Array list of current errors
1809          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1810          * @param $short Boolean short circuit on first error
1811          *
1812          * @return Array list of errors
1813          */
1814         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1815                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1816                         # We /could/ use the protection level on the source page, but it's
1817                         # fairly ugly as we have to establish a precedence hierarchy for pages
1818                         # included by multiple cascade-protected pages. So just restrict
1819                         # it to people with 'protect' permission, as they could remove the
1820                         # protection anyway.
1821                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1822                         # Cascading protection depends on more than this page...
1823                         # Several cascading protected pages may include this page...
1824                         # Check each cascading level
1825                         # This is only for protection restrictions, not for all actions
1826                         if ( isset( $restrictions[$action] ) ) {
1827                                 foreach ( $restrictions[$action] as $right ) {
1828                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1829                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1830                                                 $pages = '';
1831                                                 foreach ( $cascadingSources as $page )
1832                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1833                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1834                                         }
1835                                 }
1836                         }
1837                 }
1838
1839                 return $errors;
1840         }
1841
1842         /**
1843          * Check action permissions not already checked in checkQuickPermissions
1844          *
1845          * @param $action String the action to check
1846          * @param $user User to check
1847          * @param $errors Array list of current errors
1848          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1849          * @param $short Boolean short circuit on first error
1850          *
1851          * @return Array list of errors
1852          */
1853         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1854                 global $wgDeleteRevisionsLimit, $wgLang;
1855
1856                 if ( $action == 'protect' ) {
1857                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1858                                 // If they can't edit, they shouldn't protect.
1859                                 $errors[] = array( 'protect-cantedit' );
1860                         }
1861                 } elseif ( $action == 'create' ) {
1862                         $title_protection = $this->getTitleProtection();
1863                         if( $title_protection ) {
1864                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1865                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1866                                 }
1867                                 if( $title_protection['pt_create_perm'] == '' ||
1868                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1869                                 {
1870                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1871                                 }
1872                         }
1873                 } elseif ( $action == 'move' ) {
1874                         // Check for immobile pages
1875                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1876                                 // Specific message for this case
1877                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1878                         } elseif ( !$this->isMovable() ) {
1879                                 // Less specific message for rarer cases
1880                                 $errors[] = array( 'immobile-source-page' );
1881                         }
1882                 } elseif ( $action == 'move-target' ) {
1883                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1884                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1885                         } elseif ( !$this->isMovable() ) {
1886                                 $errors[] = array( 'immobile-target-page' );
1887                         }
1888                 } elseif ( $action == 'delete' ) {
1889                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1890                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1891                         {
1892                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1893                         }
1894                 }
1895                 return $errors;
1896         }
1897
1898         /**
1899          * Check that the user isn't blocked from editting.
1900          *
1901          * @param $action String the action to check
1902          * @param $user User to check
1903          * @param $errors Array list of current errors
1904          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1905          * @param $short Boolean short circuit on first error
1906          *
1907          * @return Array list of errors
1908          */
1909         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1910                 // Account creation blocks handled at userlogin.
1911                 // Unblocking handled in SpecialUnblock
1912                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1913                         return $errors;
1914                 }
1915
1916                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1917
1918                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1919                         $errors[] = array( 'confirmedittext' );
1920                 }
1921
1922                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1923                         // Don't block the user from editing their own talk page unless they've been
1924                         // explicitly blocked from that too.
1925                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1926                         $block = $user->getBlock();
1927
1928                         // This is from OutputPage::blockedPage
1929                         // Copied at r23888 by werdna
1930
1931                         $id = $user->blockedBy();
1932                         $reason = $user->blockedFor();
1933                         if ( $reason == '' ) {
1934                                 $reason = wfMsg( 'blockednoreason' );
1935                         }
1936                         $ip = $user->getRequest()->getIP();
1937
1938                         if ( is_numeric( $id ) ) {
1939                                 $name = User::whoIs( $id );
1940                         } else {
1941                                 $name = $id;
1942                         }
1943
1944                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1945                         $blockid = $block->getId();
1946                         $blockExpiry = $block->getExpiry();
1947                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
1948                         if ( $blockExpiry == 'infinity' ) {
1949                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1950                         } else {
1951                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1952                         }
1953
1954                         $intended = strval( $block->getTarget() );
1955
1956                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1957                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1958                 }
1959
1960                 return $errors;
1961         }
1962
1963         /**
1964          * Check that the user is allowed to read this page.
1965          *
1966          * @param $action String the action to check
1967          * @param $user User to check
1968          * @param $errors Array list of current errors
1969          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1970          * @param $short Boolean short circuit on first error
1971          *
1972          * @return Array list of errors
1973          */
1974         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1975                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
1976                 static $useShortcut = null;
1977
1978                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1979                 if ( is_null( $useShortcut ) ) {
1980                         $useShortcut = true;
1981                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1982                                 # Not a public wiki, so no shortcut
1983                                 $useShortcut = false;
1984                         } elseif ( !empty( $wgRevokePermissions ) ) {
1985                                 /**
1986                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1987                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1988                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1989                                  * reading is allowed.
1990                                  */
1991                                 foreach ( $wgRevokePermissions as $perms ) {
1992                                         if ( !empty( $perms['read'] ) ) {
1993                                                 # We might be removing the read right from the user, so no shortcut
1994                                                 $useShortcut = false;
1995                                                 break;
1996                                         }
1997                                 }
1998                         }
1999                 }
2000
2001                 $whitelisted = false;
2002                 if ( $useShortcut ) {
2003                         # Shortcut for public wikis, allows skipping quite a bit of code
2004                         $whitelisted = true;
2005                 } elseif ( $user->isAllowed( 'read' ) ) {
2006                         # If the user is allowed to read pages, he is allowed to read all pages
2007                         $whitelisted = true;
2008                 } elseif ( $this->isSpecial( 'Userlogin' )
2009                         || $this->isSpecial( 'ChangePassword' )
2010                         || $this->isSpecial( 'PasswordReset' )
2011                 ) {
2012                         # Always grant access to the login page.
2013                         # Even anons need to be able to log in.
2014                         $whitelisted = true;
2015                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2016                         # Time to check the whitelist
2017                         # Only do these checks is there's something to check against
2018                         $name = $this->getPrefixedText();
2019                         $dbName = $this->getPrefixedDBKey();
2020
2021                         // Check for explicit whitelisting with and without underscores
2022                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2023                                 $whitelisted = true;
2024                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2025                                 # Old settings might have the title prefixed with
2026                                 # a colon for main-namespace pages
2027                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2028                                         $whitelisted = true;
2029                                 }
2030                         } elseif ( $this->isSpecialPage() ) {
2031                                 # If it's a special page, ditch the subpage bit and check again
2032                                 $name = $this->getDBkey();
2033                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2034                                 if ( $name !== false ) {
2035                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2036                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2037                                                 $whitelisted = true;
2038                                         }
2039                                 }
2040                         }
2041                 }
2042
2043                 if ( !$whitelisted ) {
2044                         # If the title is not whitelisted, give extensions a chance to do so...
2045                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2046                         if ( !$whitelisted ) {
2047                                 $errors[] = $this->missingPermissionError( $action, $short );
2048                         }
2049                 }
2050
2051                 return $errors;
2052         }
2053
2054         /**
2055          * Get a description array when the user doesn't have the right to perform
2056          * $action (i.e. when User::isAllowed() returns false)
2057          *
2058          * @param $action String the action to check
2059          * @param $short Boolean short circuit on first error
2060          * @return Array list of errors
2061          */
2062         private function missingPermissionError( $action, $short ) {
2063                 // We avoid expensive display logic for quickUserCan's and such
2064                 if ( $short ) {
2065                         return array( 'badaccess-group0' );
2066                 }
2067
2068                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2069                         User::getGroupsWithPermission( $action ) );
2070
2071                 if ( count( $groups ) ) {
2072                         global $wgLang;
2073                         return array(
2074                                 'badaccess-groups',
2075                                 $wgLang->commaList( $groups ),
2076                                 count( $groups )
2077                         );
2078                 } else {
2079                         return array( 'badaccess-group0' );
2080                 }
2081         }
2082
2083         /**
2084          * Can $user perform $action on this page? This is an internal function,
2085          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2086          * checks on wfReadOnly() and blocks)
2087          *
2088          * @param $action String action that permission needs to be checked for
2089          * @param $user User to check
2090          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2091          * @param $short Bool Set this to true to stop after the first permission error.
2092          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2093          */
2094         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2095                 wfProfileIn( __METHOD__ );
2096
2097                 # Read has special handling
2098                 if ( $action == 'read' ) {
2099                         $checks = array(
2100                                 'checkPermissionHooks',
2101                                 'checkReadPermissions',
2102                         );
2103                 } else {
2104                         $checks = array(
2105                                 'checkQuickPermissions',
2106                                 'checkPermissionHooks',
2107                                 'checkSpecialsAndNSPermissions',
2108                                 'checkCSSandJSPermissions',
2109                                 'checkPageRestrictions',
2110                                 'checkCascadingSourcesRestrictions',
2111                                 'checkActionPermissions',
2112                                 'checkUserBlock'
2113                         );
2114                 }
2115
2116                 $errors = array();
2117                 while( count( $checks ) > 0 &&
2118                                 !( $short && count( $errors ) > 0 ) ) {
2119                         $method = array_shift( $checks );
2120                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2121                 }
2122
2123                 wfProfileOut( __METHOD__ );
2124                 return $errors;
2125         }
2126
2127         /**
2128          * Protect css subpages of user pages: can $wgUser edit
2129          * this page?
2130          *
2131          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2132          * @return Bool
2133          */
2134         public function userCanEditCssSubpage() {
2135                 global $wgUser;
2136                 wfDeprecated( __METHOD__, '1.19' );
2137                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2138                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2139         }
2140
2141         /**
2142          * Protect js subpages of user pages: can $wgUser edit
2143          * this page?
2144          *
2145          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2146          * @return Bool
2147          */
2148         public function userCanEditJsSubpage() {
2149                 global $wgUser;
2150                 wfDeprecated( __METHOD__, '1.19' );
2151                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2152                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2153         }
2154
2155         /**
2156          * Get a filtered list of all restriction types supported by this wiki.
2157          * @param bool $exists True to get all restriction types that apply to
2158          * titles that do exist, False for all restriction types that apply to
2159          * titles that do not exist
2160          * @return array
2161          */
2162         public static function getFilteredRestrictionTypes( $exists = true ) {
2163                 global $wgRestrictionTypes;
2164                 $types = $wgRestrictionTypes;
2165                 if ( $exists ) {
2166                         # Remove the create restriction for existing titles
2167                         $types = array_diff( $types, array( 'create' ) );
2168                 } else {
2169                         # Only the create and upload restrictions apply to non-existing titles
2170                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2171                 }
2172                 return $types;
2173         }
2174
2175         /**
2176          * Returns restriction types for the current Title
2177          *
2178          * @return array applicable restriction types
2179          */
2180         public function getRestrictionTypes() {
2181                 if ( $this->isSpecialPage() ) {
2182                         return array();
2183                 }
2184
2185                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2186
2187                 if ( $this->getNamespace() != NS_FILE ) {
2188                         # Remove the upload restriction for non-file titles
2189                         $types = array_diff( $types, array( 'upload' ) );
2190                 }
2191
2192                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2193
2194                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2195                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2196
2197                 return $types;
2198         }
2199
2200         /**
2201          * Is this title subject to title protection?
2202          * Title protection is the one applied against creation of such title.
2203          *
2204          * @return Mixed An associative array representing any existent title
2205          *   protection, or false if there's none.
2206          */
2207         private function getTitleProtection() {
2208                 // Can't protect pages in special namespaces
2209                 if ( $this->getNamespace() < 0 ) {
2210                         return false;
2211                 }
2212
2213                 // Can't protect pages that exist.
2214                 if ( $this->exists() ) {
2215                         return false;
2216                 }
2217
2218                 if ( !isset( $this->mTitleProtection ) ) {
2219                         $dbr = wfGetDB( DB_SLAVE );
2220                         $res = $dbr->select( 'protected_titles', '*',
2221                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2222                                 __METHOD__ );
2223
2224                         // fetchRow returns false if there are no rows.
2225                         $this->mTitleProtection = $dbr->fetchRow( $res );
2226                 }
2227                 return $this->mTitleProtection;
2228         }
2229
2230         /**
2231          * Update the title protection status
2232          *
2233          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2234          * @param $create_perm String Permission required for creation
2235          * @param $reason String Reason for protection
2236          * @param $expiry String Expiry timestamp
2237          * @return boolean true
2238          */
2239         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2240                 wfDeprecated( __METHOD__, '1.19' );
2241
2242                 global $wgUser;
2243
2244                 $limit = array( 'create' => $create_perm );
2245                 $expiry = array( 'create' => $expiry );
2246
2247                 $page = WikiPage::factory( $this );
2248                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2249
2250                 return $status->isOK();
2251         }
2252
2253         /**
2254          * Remove any title protection due to page existing
2255          */
2256         public function deleteTitleProtection() {
2257                 $dbw = wfGetDB( DB_MASTER );
2258
2259                 $dbw->delete(
2260                         'protected_titles',
2261                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2262                         __METHOD__
2263                 );
2264                 $this->mTitleProtection = false;
2265         }
2266
2267         /**
2268          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2269          *
2270          * @param $action String Action to check (default: edit)
2271          * @return Bool
2272          */
2273         public function isSemiProtected( $action = 'edit' ) {
2274                 if ( $this->exists() ) {
2275                         $restrictions = $this->getRestrictions( $action );
2276                         if ( count( $restrictions ) > 0 ) {
2277                                 foreach ( $restrictions as $restriction ) {
2278                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2279                                                 return false;
2280                                         }
2281                                 }
2282                         } else {
2283                                 # Not protected
2284                                 return false;
2285                         }
2286                         return true;
2287                 } else {
2288                         # If it doesn't exist, it can't be protected
2289                         return false;
2290                 }
2291         }
2292
2293         /**
2294          * Does the title correspond to a protected article?
2295          *
2296          * @param $action String the action the page is protected from,
2297          * by default checks all actions.
2298          * @return Bool
2299          */
2300         public function isProtected( $action = '' ) {
2301                 global $wgRestrictionLevels;
2302
2303                 $restrictionTypes = $this->getRestrictionTypes();
2304
2305                 # Special pages have inherent protection
2306                 if( $this->isSpecialPage() ) {
2307                         return true;
2308                 }
2309
2310                 # Check regular protection levels
2311                 foreach ( $restrictionTypes as $type ) {
2312                         if ( $action == $type || $action == '' ) {
2313                                 $r = $this->getRestrictions( $type );
2314                                 foreach ( $wgRestrictionLevels as $level ) {
2315                                         if ( in_array( $level, $r ) && $level != '' ) {
2316                                                 return true;
2317                                         }
2318                                 }
2319                         }
2320                 }
2321
2322                 return false;
2323         }
2324
2325         /**
2326          * Determines if $user is unable to edit this page because it has been protected
2327          * by $wgNamespaceProtection.
2328          *
2329          * @param $user User object to check permissions
2330          * @return Bool
2331          */
2332         public function isNamespaceProtected( User $user ) {
2333                 global $wgNamespaceProtection;
2334
2335                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2336                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2337                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2338                                         return true;
2339                                 }
2340                         }
2341                 }
2342                 return false;
2343         }
2344
2345         /**
2346          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2347          *
2348          * @return Bool If the page is subject to cascading restrictions.
2349          */
2350         public function isCascadeProtected() {
2351                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2352                 return ( $sources > 0 );
2353         }
2354
2355         /**
2356          * Cascading protection: Get the source of any cascading restrictions on this page.
2357          *
2358          * @param $getPages Bool Whether or not to retrieve the actual pages
2359          *        that the restrictions have come from.
2360          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2361          *     have come, false for none, or true if such restrictions exist, but $getPages
2362          *     was not set.  The restriction array is an array of each type, each of which
2363          *     contains a array of unique groups.
2364          */
2365         public function getCascadeProtectionSources( $getPages = true ) {
2366                 global $wgContLang;
2367                 $pagerestrictions = array();
2368
2369                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2370                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2371                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2372                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2373                 }
2374
2375                 wfProfileIn( __METHOD__ );
2376
2377                 $dbr = wfGetDB( DB_SLAVE );
2378
2379                 if ( $this->getNamespace() == NS_FILE ) {
2380                         $tables = array( 'imagelinks', 'page_restrictions' );
2381                         $where_clauses = array(
2382                                 'il_to' => $this->getDBkey(),
2383                                 'il_from=pr_page',
2384                                 'pr_cascade' => 1
2385                         );
2386                 } else {
2387                         $tables = array( 'templatelinks', 'page_restrictions' );
2388                         $where_clauses = array(
2389                                 'tl_namespace' => $this->getNamespace(),
2390                                 'tl_title' => $this->getDBkey(),
2391                                 'tl_from=pr_page',
2392                                 'pr_cascade' => 1
2393                         );
2394                 }
2395
2396                 if ( $getPages ) {
2397                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2398                                                    'pr_expiry', 'pr_type', 'pr_level' );
2399                         $where_clauses[] = 'page_id=pr_page';
2400                         $tables[] = 'page';
2401                 } else {
2402                         $cols = array( 'pr_expiry' );
2403                 }
2404
2405                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2406
2407                 $sources = $getPages ? array() : false;
2408                 $now = wfTimestampNow();
2409                 $purgeExpired = false;
2410
2411                 foreach ( $res as $row ) {
2412                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2413                         if ( $expiry > $now ) {
2414                                 if ( $getPages ) {
2415                                         $page_id = $row->pr_page;
2416                                         $page_ns = $row->page_namespace;
2417                                         $page_title = $row->page_title;
2418                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2419                                         # Add groups needed for each restriction type if its not already there
2420                                         # Make sure this restriction type still exists
2421
2422                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2423                                                 $pagerestrictions[$row->pr_type] = array();
2424                                         }
2425
2426                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2427                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2428                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2429                                         }
2430                                 } else {
2431                                         $sources = true;
2432                                 }
2433                         } else {
2434                                 // Trigger lazy purge of expired restrictions from the db
2435                                 $purgeExpired = true;
2436                         }
2437                 }
2438                 if ( $purgeExpired ) {
2439                         Title::purgeExpiredRestrictions();
2440                 }
2441
2442                 if ( $getPages ) {
2443                         $this->mCascadeSources = $sources;
2444                         $this->mCascadingRestrictions = $pagerestrictions;
2445                 } else {
2446                         $this->mHasCascadingRestrictions = $sources;
2447                 }
2448
2449                 wfProfileOut( __METHOD__ );
2450                 return array( $sources, $pagerestrictions );
2451         }
2452
2453         /**
2454          * Accessor/initialisation for mRestrictions
2455          *
2456          * @param $action String action that permission needs to be checked for
2457          * @return Array of Strings the array of groups allowed to edit this article
2458          */
2459         public function getRestrictions( $action ) {
2460                 if ( !$this->mRestrictionsLoaded ) {
2461                         $this->loadRestrictions();
2462                 }
2463                 return isset( $this->mRestrictions[$action] )
2464                                 ? $this->mRestrictions[$action]
2465                                 : array();
2466         }
2467
2468         /**
2469          * Get the expiry time for the restriction against a given action
2470          *
2471          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2472          *      or not protected at all, or false if the action is not recognised.
2473          */
2474         public function getRestrictionExpiry( $action ) {
2475                 if ( !$this->mRestrictionsLoaded ) {
2476                         $this->loadRestrictions();
2477                 }
2478                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2479         }
2480
2481         /**
2482          * Returns cascading restrictions for the current article
2483          *
2484          * @return Boolean
2485          */
2486         function areRestrictionsCascading() {
2487                 if ( !$this->mRestrictionsLoaded ) {
2488                         $this->loadRestrictions();
2489                 }
2490
2491                 return $this->mCascadeRestriction;
2492         }
2493
2494         /**
2495          * Loads a string into mRestrictions array
2496          *
2497          * @param $res Resource restrictions as an SQL result.
2498          * @param $oldFashionedRestrictions String comma-separated list of page
2499          *        restrictions from page table (pre 1.10)
2500          */
2501         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2502                 $rows = array();
2503
2504                 foreach ( $res as $row ) {
2505                         $rows[] = $row;
2506                 }
2507
2508                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2509         }
2510
2511         /**
2512          * Compiles list of active page restrictions from both page table (pre 1.10)
2513          * and page_restrictions table for this existing page.
2514          * Public for usage by LiquidThreads.
2515          *
2516          * @param $rows array of db result objects
2517          * @param $oldFashionedRestrictions string comma-separated list of page
2518          *        restrictions from page table (pre 1.10)
2519          */
2520         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2521                 global $wgContLang;
2522                 $dbr = wfGetDB( DB_SLAVE );
2523
2524                 $restrictionTypes = $this->getRestrictionTypes();
2525
2526                 foreach ( $restrictionTypes as $type ) {
2527                         $this->mRestrictions[$type] = array();
2528                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2529                 }
2530
2531                 $this->mCascadeRestriction = false;
2532
2533                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2534
2535                 if ( $oldFashionedRestrictions === null ) {
2536                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2537                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2538                 }
2539
2540                 if ( $oldFashionedRestrictions != '' ) {
2541
2542                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2543                                 $temp = explode( '=', trim( $restrict ) );
2544                                 if ( count( $temp ) == 1 ) {
2545                                         // old old format should be treated as edit/move restriction
2546                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2547                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2548                                 } else {
2549                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2550                                 }
2551                         }
2552
2553                         $this->mOldRestrictions = true;
2554
2555                 }
2556
2557                 if ( count( $rows ) ) {
2558                         # Current system - load second to make them override.
2559                         $now = wfTimestampNow();
2560                         $purgeExpired = false;
2561
2562                         # Cycle through all the restrictions.
2563                         foreach ( $rows as $row ) {
2564
2565                                 // Don't take care of restrictions types that aren't allowed
2566                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2567                                         continue;
2568
2569                                 // This code should be refactored, now that it's being used more generally,
2570                                 // But I don't really see any harm in leaving it in Block for now -werdna
2571                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2572
2573                                 // Only apply the restrictions if they haven't expired!
2574                                 if ( !$expiry || $expiry > $now ) {
2575                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2576                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2577
2578                                         $this->mCascadeRestriction |= $row->pr_cascade;
2579                                 } else {
2580                                         // Trigger a lazy purge of expired restrictions
2581                                         $purgeExpired = true;
2582                                 }
2583                         }
2584
2585                         if ( $purgeExpired ) {
2586                                 Title::purgeExpiredRestrictions();
2587                         }
2588                 }
2589
2590                 $this->mRestrictionsLoaded = true;
2591         }
2592
2593         /**
2594          * Load restrictions from the page_restrictions table
2595          *
2596          * @param $oldFashionedRestrictions String comma-separated list of page
2597          *        restrictions from page table (pre 1.10)
2598          */
2599         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2600                 global $wgContLang;
2601                 if ( !$this->mRestrictionsLoaded ) {
2602                         if ( $this->exists() ) {
2603                                 $dbr = wfGetDB( DB_SLAVE );
2604
2605                                 $res = $dbr->select(
2606                                         'page_restrictions',
2607                                         '*',
2608                                         array( 'pr_page' => $this->getArticleID() ),
2609                                         __METHOD__
2610                                 );
2611
2612                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2613                         } else {
2614                                 $title_protection = $this->getTitleProtection();
2615
2616                                 if ( $title_protection ) {
2617                                         $now = wfTimestampNow();
2618                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2619
2620                                         if ( !$expiry || $expiry > $now ) {
2621                                                 // Apply the restrictions
2622                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2623                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2624                                         } else { // Get rid of the old restrictions
2625                                                 Title::purgeExpiredRestrictions();
2626                                                 $this->mTitleProtection = false;
2627                                         }
2628                                 } else {
2629                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2630                                 }
2631                                 $this->mRestrictionsLoaded = true;
2632                         }
2633                 }
2634         }
2635
2636         /**
2637          * Flush the protection cache in this object and force reload from the database.
2638          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2639          */
2640         public function flushRestrictions() {
2641                 $this->mRestrictionsLoaded = false;
2642                 $this->mTitleProtection = null;
2643         }
2644
2645         /**
2646          * Purge expired restrictions from the page_restrictions table
2647          */
2648         static function purgeExpiredRestrictions() {
2649                 $dbw = wfGetDB( DB_MASTER );
2650                 $dbw->delete(
2651                         'page_restrictions',
2652                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2653                         __METHOD__
2654                 );
2655
2656                 $dbw->delete(
2657                         'protected_titles',
2658                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2659                         __METHOD__
2660                 );
2661         }
2662
2663         /**
2664          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2665          *
2666          * @return Bool
2667          */
2668         public function hasSubpages() {
2669                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2670                         # Duh
2671                         return false;
2672                 }
2673
2674                 # We dynamically add a member variable for the purpose of this method
2675                 # alone to cache the result.  There's no point in having it hanging
2676                 # around uninitialized in every Title object; therefore we only add it
2677                 # if needed and don't declare it statically.
2678                 if ( isset( $this->mHasSubpages ) ) {
2679                         return $this->mHasSubpages;
2680                 }
2681
2682                 $subpages = $this->getSubpages( 1 );
2683                 if ( $subpages instanceof TitleArray ) {
2684                         return $this->mHasSubpages = (bool)$subpages->count();
2685                 }
2686                 return $this->mHasSubpages = false;
2687         }
2688
2689         /**
2690          * Get all subpages of this page.
2691          *
2692          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2693          * @return mixed TitleArray, or empty array if this page's namespace
2694          *  doesn't allow subpages
2695          */
2696         public function getSubpages( $limit = -1 ) {
2697                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2698                         return array();
2699                 }
2700
2701                 $dbr = wfGetDB( DB_SLAVE );
2702                 $conds['page_namespace'] = $this->getNamespace();
2703                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2704                 $options = array();
2705                 if ( $limit > -1 ) {
2706                         $options['LIMIT'] = $limit;
2707                 }
2708                 return $this->mSubpages = TitleArray::newFromResult(
2709                         $dbr->select( 'page',
2710                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2711                                 $conds,
2712                                 __METHOD__,
2713                                 $options
2714                         )
2715                 );
2716         }
2717
2718         /**
2719          * Is there a version of this page in the deletion archive?
2720          *
2721          * @return Int the number of archived revisions
2722          */
2723         public function isDeleted() {
2724                 if ( $this->getNamespace() < 0 ) {
2725                         $n = 0;
2726                 } else {
2727                         $dbr = wfGetDB( DB_SLAVE );
2728
2729                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2730                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2731                                 __METHOD__
2732                         );
2733                         if ( $this->getNamespace() == NS_FILE ) {
2734                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2735                                         array( 'fa_name' => $this->getDBkey() ),
2736                                         __METHOD__
2737                                 );
2738                         }
2739                 }
2740                 return (int)$n;
2741         }
2742
2743         /**
2744          * Is there a version of this page in the deletion archive?
2745          *
2746          * @return Boolean
2747          */
2748         public function isDeletedQuick() {
2749                 if ( $this->getNamespace() < 0 ) {
2750                         return false;
2751                 }
2752                 $dbr = wfGetDB( DB_SLAVE );
2753                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2754                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2755                         __METHOD__
2756                 );
2757                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2758                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2759                                 array( 'fa_name' => $this->getDBkey() ),
2760                                 __METHOD__
2761                         );
2762                 }
2763                 return $deleted;
2764         }
2765
2766         /**
2767          * Get the article ID for this Title from the link cache,
2768          * adding it if necessary
2769          *
2770          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2771          *  for update
2772          * @return Int the ID
2773          */
2774         public function getArticleID( $flags = 0 ) {
2775                 if ( $this->getNamespace() < 0 ) {
2776                         return $this->mArticleID = 0;
2777                 }
2778                 $linkCache = LinkCache::singleton();
2779                 if ( $flags & self::GAID_FOR_UPDATE ) {
2780                         $oldUpdate = $linkCache->forUpdate( true );
2781                         $linkCache->clearLink( $this );
2782                         $this->mArticleID = $linkCache->addLinkObj( $this );
2783                         $linkCache->forUpdate( $oldUpdate );
2784                 } else {
2785                         if ( -1 == $this->mArticleID ) {
2786                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2787                         }
2788                 }
2789                 return $this->mArticleID;
2790         }
2791
2792         /**
2793          * Is this an article that is a redirect page?
2794          * Uses link cache, adding it if necessary
2795          *
2796          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2797          * @return Bool
2798          */
2799         public function isRedirect( $flags = 0 ) {
2800                 if ( !is_null( $this->mRedirect ) ) {
2801                         return $this->mRedirect;
2802                 }
2803                 # Calling getArticleID() loads the field from cache as needed
2804                 if ( !$this->getArticleID( $flags ) ) {
2805                         return $this->mRedirect = false;
2806                 }
2807                 $linkCache = LinkCache::singleton();
2808                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2809
2810                 return $this->mRedirect;
2811         }
2812
2813         /**
2814          * What is the length of this page?
2815          * Uses link cache, adding it if necessary
2816          *
2817          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2818          * @return Int
2819          */
2820         public function getLength( $flags = 0 ) {
2821                 if ( $this->mLength != -1 ) {
2822                         return $this->mLength;
2823                 }
2824                 # Calling getArticleID() loads the field from cache as needed
2825                 if ( !$this->getArticleID( $flags ) ) {
2826                         return $this->mLength = 0;
2827                 }
2828                 $linkCache = LinkCache::singleton();
2829                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2830
2831                 return $this->mLength;
2832         }
2833
2834         /**
2835          * What is the page_latest field for this page?
2836          *
2837          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2838          * @return Int or 0 if the page doesn't exist
2839          */
2840         public function getLatestRevID( $flags = 0 ) {
2841                 if ( $this->mLatestID !== false ) {
2842                         return intval( $this->mLatestID );
2843                 }
2844                 # Calling getArticleID() loads the field from cache as needed
2845                 if ( !$this->getArticleID( $flags ) ) {
2846                         return $this->mLatestID = 0;
2847                 }
2848                 $linkCache = LinkCache::singleton();
2849                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2850
2851                 return $this->mLatestID;
2852         }
2853
2854         /**
2855          * This clears some fields in this object, and clears any associated
2856          * keys in the "bad links" section of the link cache.
2857          *
2858          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2859          * loading of the new page_id. It's also called from
2860          * WikiPage::doDeleteArticle()
2861          *
2862          * @param $newid Int the new Article ID
2863          */
2864         public function resetArticleID( $newid ) {
2865                 $linkCache = LinkCache::singleton();
2866                 $linkCache->clearLink( $this );
2867
2868                 if ( $newid === false ) {
2869                         $this->mArticleID = -1;
2870                 } else {
2871                         $this->mArticleID = intval( $newid );
2872                 }
2873                 $this->mRestrictionsLoaded = false;
2874                 $this->mRestrictions = array();
2875                 $this->mRedirect = null;
2876                 $this->mLength = -1;
2877                 $this->mLatestID = false;
2878                 $this->mEstimateRevisions = null;
2879         }
2880
2881         /**
2882          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2883          *
2884          * @param $text String containing title to capitalize
2885          * @param $ns int namespace index, defaults to NS_MAIN
2886          * @return String containing capitalized title
2887          */
2888         public static function capitalize( $text, $ns = NS_MAIN ) {
2889                 global $wgContLang;
2890
2891                 if ( MWNamespace::isCapitalized( $ns ) ) {
2892                         return $wgContLang->ucfirst( $text );
2893                 } else {
2894                         return $text;
2895                 }
2896         }
2897
2898         /**
2899          * Secure and split - main initialisation function for this object
2900          *
2901          * Assumes that mDbkeyform has been set, and is urldecoded
2902          * and uses underscores, but not otherwise munged.  This function
2903          * removes illegal characters, splits off the interwiki and
2904          * namespace prefixes, sets the other forms, and canonicalizes
2905          * everything.
2906          *
2907          * @return Bool true on success
2908          */
2909         private function secureAndSplit() {
2910                 global $wgContLang, $wgLocalInterwiki;
2911
2912                 # Initialisation
2913                 $this->mInterwiki = $this->mFragment = '';
2914                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2915
2916                 $dbkey = $this->mDbkeyform;
2917
2918                 # Strip Unicode bidi override characters.
2919                 # Sometimes they slip into cut-n-pasted page titles, where the
2920                 # override chars get included in list displays.
2921                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2922
2923                 # Clean up whitespace
2924                 # Note: use of the /u option on preg_replace here will cause
2925                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2926                 # conveniently disabling them.
2927                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2928                 $dbkey = trim( $dbkey, '_' );
2929
2930                 if ( $dbkey == '' ) {
2931                         return false;
2932                 }
2933
2934                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2935                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2936                         return false;
2937                 }
2938
2939                 $this->mDbkeyform = $dbkey;
2940
2941                 # Initial colon indicates main namespace rather than specified default
2942                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2943                 if ( ':' == $dbkey[0] ) {
2944                         $this->mNamespace = NS_MAIN;
2945                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2946                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2947                 }
2948
2949                 # Namespace or interwiki prefix
2950                 $firstPass = true;
2951                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2952                 do {
2953                         $m = array();
2954                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2955                                 $p = $m[1];
2956                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2957                                         # Ordinary namespace
2958                                         $dbkey = $m[2];
2959                                         $this->mNamespace = $ns;
2960                                         # For Talk:X pages, check if X has a "namespace" prefix
2961                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2962                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2963                                                         # Disallow Talk:File:x type titles...
2964                                                         return false;
2965                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2966                                                         # Disallow Talk:Interwiki:x type titles...
2967                                                         return false;
2968                                                 }
2969                                         }
2970                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2971                                         if ( !$firstPass ) {
2972                                                 # Can't make a local interwiki link to an interwiki link.
2973                                                 # That's just crazy!
2974                                                 return false;
2975                                         }
2976
2977                                         # Interwiki link
2978                                         $dbkey = $m[2];
2979                                         $this->mInterwiki = $wgContLang->lc( $p );
2980
2981                                         # Redundant interwiki prefix to the local wiki
2982                                         if ( $wgLocalInterwiki !== false
2983                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2984                                         {
2985                                                 if ( $dbkey == '' ) {
2986                                                         # Can't have an empty self-link
2987                                                         return false;
2988                                                 }
2989                                                 $this->mInterwiki = '';
2990                                                 $firstPass = false;
2991                                                 # Do another namespace split...
2992                                                 continue;
2993                                         }
2994
2995                                         # If there's an initial colon after the interwiki, that also
2996                                         # resets the default namespace
2997                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2998                                                 $this->mNamespace = NS_MAIN;
2999                                                 $dbkey = substr( $dbkey, 1 );
3000                                         }
3001                                 }
3002                                 # If there's no recognized interwiki or namespace,
3003                                 # then let the colon expression be part of the title.
3004                         }
3005                         break;
3006                 } while ( true );
3007
3008                 # We already know that some pages won't be in the database!
3009                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3010                         $this->mArticleID = 0;
3011                 }
3012                 $fragment = strstr( $dbkey, '#' );
3013                 if ( false !== $fragment ) {
3014                         $this->setFragment( $fragment );
3015                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3016                         # remove whitespace again: prevents "Foo_bar_#"
3017                         # becoming "Foo_bar_"
3018                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3019                 }
3020
3021                 # Reject illegal characters.
3022                 $rxTc = self::getTitleInvalidRegex();
3023                 if ( preg_match( $rxTc, $dbkey ) ) {
3024                         return false;
3025                 }
3026
3027                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3028                 # reachable due to the way web browsers deal with 'relative' URLs.
3029                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3030                 if ( strpos( $dbkey, '.' ) !== false &&
3031                          ( $dbkey === '.' || $dbkey === '..' ||
3032                            strpos( $dbkey, './' ) === 0  ||
3033                            strpos( $dbkey, '../' ) === 0 ||
3034                            strpos( $dbkey, '/./' ) !== false ||
3035                            strpos( $dbkey, '/../' ) !== false  ||
3036                            substr( $dbkey, -2 ) == '/.' ||
3037                            substr( $dbkey, -3 ) == '/..' ) )
3038                 {
3039                         return false;
3040                 }
3041
3042                 # Magic tilde sequences? Nu-uh!
3043                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3044                         return false;
3045                 }
3046
3047                 # Limit the size of titles to 255 bytes. This is typically the size of the
3048                 # underlying database field. We make an exception for special pages, which
3049                 # don't need to be stored in the database, and may edge over 255 bytes due
3050                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3051                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3052                   strlen( $dbkey ) > 512 )
3053                 {
3054                         return false;
3055                 }
3056
3057                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3058                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3059                 # other site might be case-sensitive.
3060                 $this->mUserCaseDBKey = $dbkey;
3061                 if ( $this->mInterwiki == '' ) {
3062                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3063                 }
3064
3065                 # Can't make a link to a namespace alone... "empty" local links can only be
3066                 # self-links with a fragment identifier.
3067                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3068                         return false;
3069                 }
3070
3071                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3072                 // IP names are not allowed for accounts, and can only be referring to
3073                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3074                 // there are numerous ways to present the same IP. Having sp:contribs scan
3075                 // them all is silly and having some show the edits and others not is
3076                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3077                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3078                         ? IP::sanitizeIP( $dbkey )
3079                         : $dbkey;
3080
3081                 // Any remaining initial :s are illegal.
3082                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3083                         return false;
3084                 }
3085
3086                 # Fill fields
3087                 $this->mDbkeyform = $dbkey;
3088                 $this->mUrlform = wfUrlencode( $dbkey );
3089
3090                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3091
3092                 return true;
3093         }
3094
3095         /**
3096          * Get an array of Title objects linking to this Title
3097          * Also stores the IDs in the link cache.
3098          *
3099          * WARNING: do not use this function on arbitrary user-supplied titles!
3100          * On heavily-used templates it will max out the memory.
3101          *
3102          * @param $options Array: may be FOR UPDATE
3103          * @param $table String: table name
3104          * @param $prefix String: fields prefix
3105          * @return Array of Title objects linking here
3106          */
3107         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3108                 if ( count( $options ) > 0 ) {
3109                         $db = wfGetDB( DB_MASTER );
3110                 } else {
3111                         $db = wfGetDB( DB_SLAVE );
3112                 }
3113
3114                 $res = $db->select(
3115                         array( 'page', $table ),
3116                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3117                         array(
3118                                 "{$prefix}_from=page_id",
3119                                 "{$prefix}_namespace" => $this->getNamespace(),
3120                                 "{$prefix}_title"     => $this->getDBkey() ),
3121                         __METHOD__,
3122                         $options
3123                 );
3124
3125                 $retVal = array();
3126                 if ( $res->numRows() ) {
3127                         $linkCache = LinkCache::singleton();
3128                         foreach ( $res as $row ) {
3129                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3130                                 if ( $titleObj ) {
3131                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3132                                         $retVal[] = $titleObj;
3133                                 }
3134                         }
3135                 }
3136                 return $retVal;
3137         }
3138
3139         /**
3140          * Get an array of Title objects using this Title as a template
3141          * Also stores the IDs in the link cache.
3142          *
3143          * WARNING: do not use this function on arbitrary user-supplied titles!
3144          * On heavily-used templates it will max out the memory.
3145          *
3146          * @param $options Array: may be FOR UPDATE
3147          * @return Array of Title the Title objects linking here
3148          */
3149         public function getTemplateLinksTo( $options = array() ) {
3150                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3151         }
3152
3153         /**
3154          * Get an array of Title objects linked from this Title
3155          * Also stores the IDs in the link cache.
3156          *
3157          * WARNING: do not use this function on arbitrary user-supplied titles!
3158          * On heavily-used templates it will max out the memory.
3159          *
3160          * @param $options Array: may be FOR UPDATE
3161          * @param $table String: table name
3162          * @param $prefix String: fields prefix
3163          * @return Array of Title objects linking here
3164          */
3165         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3166                 $id = $this->getArticleID();
3167
3168                 # If the page doesn't exist; there can't be any link from this page
3169                 if ( !$id ) {
3170                         return array();
3171                 }
3172
3173                 if ( count( $options ) > 0 ) {
3174                         $db = wfGetDB( DB_MASTER );
3175                 } else {
3176                         $db = wfGetDB( DB_SLAVE );
3177                 }
3178
3179                 $namespaceFiled = "{$prefix}_namespace";
3180                 $titleField = "{$prefix}_title";
3181
3182                 $res = $db->select(
3183                         array( $table, 'page' ),
3184                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3185                         array( "{$prefix}_from" => $id ),
3186                         __METHOD__,
3187                         $options,
3188                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3189                 );
3190
3191                 $retVal = array();
3192                 if ( $res->numRows() ) {
3193                         $linkCache = LinkCache::singleton();
3194                         foreach ( $res as $row ) {
3195                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3196                                 if ( $titleObj ) {
3197                                         if ( $row->page_id ) {
3198                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3199                                         } else {
3200                                                 $linkCache->addBadLinkObj( $titleObj );
3201                                         }
3202                                         $retVal[] = $titleObj;
3203                                 }
3204                         }
3205                 }
3206                 return $retVal;
3207         }
3208
3209         /**
3210          * Get an array of Title objects used on this Title as a template
3211          * Also stores the IDs in the link cache.
3212          *
3213          * WARNING: do not use this function on arbitrary user-supplied titles!
3214          * On heavily-used templates it will max out the memory.
3215          *
3216          * @param $options Array: may be FOR UPDATE
3217          * @return Array of Title the Title objects used here
3218          */
3219         public function getTemplateLinksFrom( $options = array() ) {
3220                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3221         }
3222
3223         /**
3224          * Get an array of Title objects referring to non-existent articles linked from this page
3225          *
3226          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3227          * @return Array of Title the Title objects
3228          */
3229         public function getBrokenLinksFrom() {
3230                 if ( $this->getArticleID() == 0 ) {
3231                         # All links from article ID 0 are false positives
3232                         return array();
3233                 }
3234
3235                 $dbr = wfGetDB( DB_SLAVE );
3236                 $res = $dbr->select(
3237                         array( 'page', 'pagelinks' ),
3238                         array( 'pl_namespace', 'pl_title' ),
3239                         array(
3240                                 'pl_from' => $this->getArticleID(),
3241                                 'page_namespace IS NULL'
3242                         ),
3243                         __METHOD__, array(),
3244                         array(
3245                                 'page' => array(
3246                                         'LEFT JOIN',
3247                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3248                                 )
3249                         )
3250                 );
3251
3252                 $retVal = array();
3253                 foreach ( $res as $row ) {
3254                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3255                 }
3256                 return $retVal;
3257         }
3258
3259
3260         /**
3261          * Get a list of URLs to purge from the Squid cache when this
3262          * page changes
3263          *
3264          * @return Array of String the URLs
3265          */
3266         public function getSquidURLs() {
3267                 global $wgContLang;
3268
3269                 $urls = array(
3270                         $this->getInternalURL(),
3271                         $this->getInternalURL( 'action=history' )
3272                 );
3273
3274                 // purge variant urls as well
3275                 if ( $wgContLang->hasVariants() ) {
3276                         $variants = $wgContLang->getVariants();
3277                         foreach ( $variants as $vCode ) {
3278                                 $urls[] = $this->getInternalURL( '', $vCode );
3279                         }
3280                 }
3281
3282                 return $urls;
3283         }
3284
3285         /**
3286          * Purge all applicable Squid URLs
3287          */
3288         public function purgeSquid() {
3289                 global $wgUseSquid;
3290                 if ( $wgUseSquid ) {
3291                         $urls = $this->getSquidURLs();
3292                         $u = new SquidUpdate( $urls );
3293                         $u->doUpdate();
3294                 }
3295         }
3296
3297         /**
3298          * Move this page without authentication
3299          *
3300          * @param $nt Title the new page Title
3301          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3302          */
3303         public function moveNoAuth( &$nt ) {
3304                 return $this->moveTo( $nt, false );
3305         }
3306
3307         /**
3308          * Check whether a given move operation would be valid.
3309          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3310          *
3311          * @param $nt Title the new title
3312          * @param $auth Bool indicates whether $wgUser's permissions
3313          *  should be checked
3314          * @param $reason String is the log summary of the move, used for spam checking
3315          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3316          */
3317         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3318                 global $wgUser;
3319
3320                 $errors = array();
3321                 if ( !$nt ) {
3322                         // Normally we'd add this to $errors, but we'll get
3323                         // lots of syntax errors if $nt is not an object
3324                         return array( array( 'badtitletext' ) );
3325                 }
3326                 if ( $this->equals( $nt ) ) {
3327                         $errors[] = array( 'selfmove' );
3328                 }
3329                 if ( !$this->isMovable() ) {
3330                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3331                 }
3332                 if ( $nt->getInterwiki() != '' ) {
3333                         $errors[] = array( 'immobile-target-namespace-iw' );
3334                 }
3335                 if ( !$nt->isMovable() ) {
3336                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3337                 }
3338
3339                 $oldid = $this->getArticleID();
3340                 $newid = $nt->getArticleID();
3341
3342                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3343                         $errors[] = array( 'articleexists' );
3344                 }
3345                 if ( ( $this->getDBkey() == '' ) ||
3346                          ( !$oldid ) ||
3347                          ( $nt->getDBkey() == '' ) ) {
3348                         $errors[] = array( 'badarticleerror' );
3349                 }
3350
3351                 // Image-specific checks
3352                 if ( $this->getNamespace() == NS_FILE ) {
3353                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3354                 }
3355
3356                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3357                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3358                 }
3359
3360                 if ( $auth ) {
3361                         $errors = wfMergeErrorArrays( $errors,
3362                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3363                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3364                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3365                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3366                 }
3367
3368                 $match = EditPage::matchSummarySpamRegex( $reason );
3369                 if ( $match !== false ) {
3370                         // This is kind of lame, won't display nice
3371                         $errors[] = array( 'spamprotectiontext' );
3372                 }
3373
3374                 $err = null;
3375                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3376                         $errors[] = array( 'hookaborted', $err );
3377                 }
3378
3379                 # The move is allowed only if (1) the target doesn't exist, or
3380                 # (2) the target is a redirect to the source, and has no history
3381                 # (so we can undo bad moves right after they're done).
3382
3383                 if ( 0 != $newid ) { # Target exists; check for validity
3384                         if ( !$this->isValidMoveTarget( $nt ) ) {
3385                                 $errors[] = array( 'articleexists' );
3386                         }
3387                 } else {
3388                         $tp = $nt->getTitleProtection();
3389                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3390                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3391                                 $errors[] = array( 'cantmove-titleprotected' );
3392                         }
3393                 }
3394                 if ( empty( $errors ) ) {
3395                         return true;
3396                 }
3397                 return $errors;
3398         }
3399
3400         /**
3401          * Check if the requested move target is a valid file move target
3402          * @param Title $nt Target title
3403          * @return array List of errors
3404          */
3405         protected function validateFileMoveOperation( $nt ) {
3406                 global $wgUser;
3407
3408                 $errors = array();
3409
3410                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3411
3412                 $file = wfLocalFile( $this );
3413                 if ( $file->exists() ) {
3414                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3415                                 $errors[] = array( 'imageinvalidfilename' );
3416                         }
3417                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3418                                 $errors[] = array( 'imagetypemismatch' );
3419                         }
3420                 }
3421
3422                 if ( $nt->getNamespace() != NS_FILE ) {
3423                         $errors[] = array( 'imagenocrossnamespace' );
3424                         // From here we want to do checks on a file object, so if we can't
3425                         // create one, we must return.
3426                         return $errors;
3427                 }
3428
3429                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3430
3431                 $destFile = wfLocalFile( $nt );
3432                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3433                         $errors[] = array( 'file-exists-sharedrepo' );
3434                 }
3435
3436                 return $errors;
3437         }
3438
3439         /**
3440          * Move a title to a new location
3441          *
3442          * @param $nt Title the new title
3443          * @param $auth Bool indicates whether $wgUser's permissions
3444          *  should be checked
3445          * @param $reason String the reason for the move
3446          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3447          *  Ignored if the user doesn't have the suppressredirect right.
3448          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3449          */
3450         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3451                 global $wgUser;
3452                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3453                 if ( is_array( $err ) ) {
3454                         // Auto-block user's IP if the account was "hard" blocked
3455                         $wgUser->spreadAnyEditBlock();
3456                         return $err;
3457                 }
3458
3459                 // If it is a file, move it first.
3460                 // It is done before all other moving stuff is done because it's hard to revert.
3461                 $dbw = wfGetDB( DB_MASTER );
3462                 if ( $this->getNamespace() == NS_FILE ) {
3463                         $file = wfLocalFile( $this );
3464                         if ( $file->exists() ) {
3465                                 $status = $file->move( $nt );
3466                                 if ( !$status->isOk() ) {
3467                                         return $status->getErrorsArray();
3468                                 }
3469                         }
3470                         // Clear RepoGroup process cache
3471                         RepoGroup::singleton()->clearCache( $this );
3472                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3473                 }
3474
3475                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3476                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3477                 $protected = $this->isProtected();
3478
3479                 // Do the actual move
3480                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3481                 if ( is_array( $err ) ) {
3482                         # @todo FIXME: What about the File we have already moved?
3483                         $dbw->rollback( __METHOD__ );
3484                         return $err;
3485                 }
3486
3487                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3488                 // cl_timestamp, which may disturb time-based lists on some sites.
3489                 $prefixes = $dbw->select(
3490                         'categorylinks',
3491                         array( 'cl_sortkey_prefix', 'cl_to' ),
3492                         array( 'cl_from' => $pageid ),
3493                         __METHOD__
3494                 );
3495                 foreach ( $prefixes as $prefixRow ) {
3496                         $prefix = $prefixRow->cl_sortkey_prefix;
3497                         $catTo = $prefixRow->cl_to;
3498                         $dbw->update( 'categorylinks',
3499                                 array(
3500                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3501                                                 $nt->getCategorySortkey( $prefix ) ),
3502                                         'cl_timestamp=cl_timestamp' ),
3503                                 array(
3504                                         'cl_from' => $pageid,
3505                                         'cl_to' => $catTo ),
3506                                 __METHOD__
3507                         );
3508                 }
3509
3510                 $redirid = $this->getArticleID();
3511
3512                 if ( $protected ) {
3513                         # Protect the redirect title as the title used to be...
3514                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3515                                 array(
3516                                         'pr_page'    => $redirid,
3517                                         'pr_type'    => 'pr_type',
3518                                         'pr_level'   => 'pr_level',
3519                                         'pr_cascade' => 'pr_cascade',
3520                                         'pr_user'    => 'pr_user',
3521                                         'pr_expiry'  => 'pr_expiry'
3522                                 ),
3523                                 array( 'pr_page' => $pageid ),
3524                                 __METHOD__,
3525                                 array( 'IGNORE' )
3526                         );
3527                         # Update the protection log
3528                         $log = new LogPage( 'protect' );
3529                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3530                         if ( $reason ) {
3531                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3532                         }
3533                         // @todo FIXME: $params?
3534                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3535                 }
3536
3537                 # Update watchlists
3538                 $oldnamespace = $this->getNamespace() & ~1;
3539                 $newnamespace = $nt->getNamespace() & ~1;
3540                 $oldtitle = $this->getDBkey();
3541                 $newtitle = $nt->getDBkey();
3542
3543                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3544                         WatchedItem::duplicateEntries( $this, $nt );
3545                 }
3546
3547                 $dbw->commit( __METHOD__ );
3548
3549                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3550                 return true;
3551         }
3552
3553         /**
3554          * Move page to a title which is either a redirect to the
3555          * source page or nonexistent
3556          *
3557          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3558          * @param $reason String The reason for the move
3559          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3560          *   if the user doesn't have the suppressredirect right
3561          */
3562         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3563                 global $wgUser, $wgContLang;
3564
3565                 if ( $nt->exists() ) {
3566                         $moveOverRedirect = true;
3567                         $logType = 'move_redir';
3568                 } else {
3569                         $moveOverRedirect = false;
3570                         $logType = 'move';
3571                 }
3572
3573                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3574
3575                 $logEntry = new ManualLogEntry( 'move', $logType );
3576                 $logEntry->setPerformer( $wgUser );
3577                 $logEntry->setTarget( $this );
3578                 $logEntry->setComment( $reason );
3579                 $logEntry->setParameters( array(
3580                         '4::target' => $nt->getPrefixedText(),
3581                         '5::noredir' => $redirectSuppressed ? '1': '0',
3582                 ) );
3583
3584                 $formatter = LogFormatter::newFromEntry( $logEntry );
3585                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3586                 $comment = $formatter->getPlainActionText();
3587                 if ( $reason ) {
3588                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3589                 }
3590                 # Truncate for whole multibyte characters.
3591                 $comment = $wgContLang->truncate( $comment, 255 );
3592
3593                 $oldid = $this->getArticleID();
3594
3595                 $dbw = wfGetDB( DB_MASTER );
3596
3597                 $newpage = WikiPage::factory( $nt );
3598
3599                 if ( $moveOverRedirect ) {
3600                         $newid = $nt->getArticleID();
3601
3602                         # Delete the old redirect. We don't save it to history since
3603                         # by definition if we've got here it's rather uninteresting.
3604                         # We have to remove it so that the next step doesn't trigger
3605                         # a conflict on the unique namespace+title index...
3606                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3607
3608                         $newpage->doDeleteUpdates( $newid );
3609                 }
3610
3611                 # Save a null revision in the page's history notifying of the move
3612                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3613                 if ( !is_object( $nullRevision ) ) {
3614                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3615                 }
3616                 $nullRevId = $nullRevision->insertOn( $dbw );
3617
3618                 # Change the name of the target page:
3619                 $dbw->update( 'page',
3620                         /* SET */ array(
3621                                 'page_namespace' => $nt->getNamespace(),
3622                                 'page_title'     => $nt->getDBkey(),
3623                         ),
3624                         /* WHERE */ array( 'page_id' => $oldid ),
3625                         __METHOD__
3626                 );
3627
3628                 $this->resetArticleID( 0 );
3629                 $nt->resetArticleID( $oldid );
3630
3631                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3632
3633                 wfRunHooks( 'NewRevisionFromEditComplete',
3634                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3635
3636                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3637
3638                 if ( !$moveOverRedirect ) {
3639                         WikiPage::onArticleCreate( $nt );
3640                 }
3641
3642                 # Recreate the redirect, this time in the other direction.
3643                 if ( $redirectSuppressed ) {
3644                         WikiPage::onArticleDelete( $this );
3645                 } else {
3646                         $mwRedir = MagicWord::get( 'redirect' );
3647                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3648                         $redirectArticle = WikiPage::factory( $this );
3649                         $newid = $redirectArticle->insertOn( $dbw );
3650                         if ( $newid ) { // sanity
3651                                 $redirectRevision = new Revision( array(
3652                                         'page'    => $newid,
3653                                         'comment' => $comment,
3654                                         'text'    => $redirectText ) );
3655                                 $redirectRevision->insertOn( $dbw );
3656                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3657
3658                                 wfRunHooks( 'NewRevisionFromEditComplete',
3659                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3660
3661                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3662                         }
3663                 }
3664
3665                 # Log the move
3666                 $logid = $logEntry->insert();
3667                 $logEntry->publish( $logid );
3668         }
3669
3670         /**
3671          * Move this page's subpages to be subpages of $nt
3672          *
3673          * @param $nt Title Move target
3674          * @param $auth bool Whether $wgUser's permissions should be checked
3675          * @param $reason string The reason for the move
3676          * @param $createRedirect bool Whether to create redirects from the old subpages to
3677          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3678          * @return mixed array with old page titles as keys, and strings (new page titles) or
3679          *     arrays (errors) as values, or an error array with numeric indices if no pages
3680          *     were moved
3681          */
3682         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3683                 global $wgMaximumMovedPages;
3684                 // Check permissions
3685                 if ( !$this->userCan( 'move-subpages' ) ) {
3686                         return array( 'cant-move-subpages' );
3687                 }
3688                 // Do the source and target namespaces support subpages?
3689                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3690                         return array( 'namespace-nosubpages',
3691                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3692                 }
3693                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3694                         return array( 'namespace-nosubpages',
3695                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3696                 }
3697
3698                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3699                 $retval = array();
3700                 $count = 0;
3701                 foreach ( $subpages as $oldSubpage ) {
3702                         $count++;
3703                         if ( $count > $wgMaximumMovedPages ) {
3704                                 $retval[$oldSubpage->getPrefixedTitle()] =
3705                                                 array( 'movepage-max-pages',
3706                                                         $wgMaximumMovedPages );
3707                                 break;
3708                         }
3709
3710                         // We don't know whether this function was called before
3711                         // or after moving the root page, so check both
3712                         // $this and $nt
3713                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3714                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3715                         {
3716                                 // When moving a page to a subpage of itself,
3717                                 // don't move it twice
3718                                 continue;
3719                         }
3720                         $newPageName = preg_replace(
3721                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3722                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3723                                         $oldSubpage->getDBkey() );
3724                         if ( $oldSubpage->isTalkPage() ) {
3725                                 $newNs = $nt->getTalkPage()->getNamespace();
3726                         } else {
3727                                 $newNs = $nt->getSubjectPage()->getNamespace();
3728                         }
3729                         # Bug 14385: we need makeTitleSafe because the new page names may
3730                         # be longer than 255 characters.
3731                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3732
3733                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3734                         if ( $success === true ) {
3735                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3736                         } else {
3737                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3738                         }
3739                 }
3740                 return $retval;
3741         }
3742
3743         /**
3744          * Checks if this page is just a one-rev redirect.
3745          * Adds lock, so don't use just for light purposes.
3746          *
3747          * @return Bool
3748          */
3749         public function isSingleRevRedirect() {
3750                 $dbw = wfGetDB( DB_MASTER );
3751                 # Is it a redirect?
3752                 $row = $dbw->selectRow( 'page',
3753                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3754                         $this->pageCond(),
3755                         __METHOD__,
3756                         array( 'FOR UPDATE' )
3757                 );
3758                 # Cache some fields we may want
3759                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3760                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3761                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3762                 if ( !$this->mRedirect ) {
3763                         return false;
3764                 }
3765                 # Does the article have a history?
3766                 $row = $dbw->selectField( array( 'page', 'revision' ),
3767                         'rev_id',
3768                         array( 'page_namespace' => $this->getNamespace(),
3769                                 'page_title' => $this->getDBkey(),
3770                                 'page_id=rev_page',
3771                                 'page_latest != rev_id'
3772                         ),
3773                         __METHOD__,
3774                         array( 'FOR UPDATE' )
3775                 );
3776                 # Return true if there was no history
3777                 return ( $row === false );
3778         }
3779
3780         /**
3781          * Checks if $this can be moved to a given Title
3782          * - Selects for update, so don't call it unless you mean business
3783          *
3784          * @param $nt Title the new title to check
3785          * @return Bool
3786          */
3787         public function isValidMoveTarget( $nt ) {
3788                 # Is it an existing file?
3789                 if ( $nt->getNamespace() == NS_FILE ) {
3790                         $file = wfLocalFile( $nt );
3791                         if ( $file->exists() ) {
3792                                 wfDebug( __METHOD__ . ": file exists\n" );
3793                                 return false;
3794                         }
3795                 }
3796                 # Is it a redirect with no history?
3797                 if ( !$nt->isSingleRevRedirect() ) {
3798                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3799                         return false;
3800                 }
3801                 # Get the article text
3802                 $rev = Revision::newFromTitle( $nt );
3803                 if( !is_object( $rev ) ){
3804                         return false;
3805                 }
3806                 $text = $rev->getText();
3807                 # Does the redirect point to the source?
3808                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3809                 $m = array();
3810                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3811                         $redirTitle = Title::newFromText( $m[1] );
3812                         if ( !is_object( $redirTitle ) ||
3813                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3814                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3815                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3816                                 return false;
3817                         }
3818                 } else {
3819                         # Fail safe
3820                         wfDebug( __METHOD__ . ": failsafe\n" );
3821                         return false;
3822                 }
3823                 return true;
3824         }
3825
3826         /**
3827          * Get categories to which this Title belongs and return an array of
3828          * categories' names.
3829          *
3830          * @return Array of parents in the form:
3831          *        $parent => $currentarticle
3832          */
3833         public function getParentCategories() {
3834                 global $wgContLang;
3835
3836                 $data = array();
3837
3838                 $titleKey = $this->getArticleID();
3839
3840                 if ( $titleKey === 0 ) {
3841                         return $data;
3842                 }
3843
3844                 $dbr = wfGetDB( DB_SLAVE );
3845
3846                 $res = $dbr->select( 'categorylinks', '*',
3847                         array(
3848                                 'cl_from' => $titleKey,
3849                         ),
3850                         __METHOD__,
3851                         array()
3852                 );
3853
3854                 if ( $dbr->numRows( $res ) > 0 ) {
3855                         foreach ( $res as $row ) {
3856                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3857                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3858                         }
3859                 }
3860                 return $data;
3861         }
3862
3863         /**
3864          * Get a tree of parent categories
3865          *
3866          * @param $children Array with the children in the keys, to check for circular refs
3867          * @return Array Tree of parent categories
3868          */
3869         public function getParentCategoryTree( $children = array() ) {
3870                 $stack = array();
3871                 $parents = $this->getParentCategories();
3872
3873                 if ( $parents ) {
3874                         foreach ( $parents as $parent => $current ) {
3875                                 if ( array_key_exists( $parent, $children ) ) {
3876                                         # Circular reference
3877                                         $stack[$parent] = array();
3878                                 } else {
3879                                         $nt = Title::newFromText( $parent );
3880                                         if ( $nt ) {
3881                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3882                                         }
3883                                 }
3884                         }
3885                 }
3886
3887                 return $stack;
3888         }
3889
3890         /**
3891          * Get an associative array for selecting this title from
3892          * the "page" table
3893          *
3894          * @return Array suitable for the $where parameter of DB::select()
3895          */
3896         public function pageCond() {
3897                 if ( $this->mArticleID > 0 ) {
3898                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3899                         return array( 'page_id' => $this->mArticleID );
3900                 } else {
3901                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3902                 }
3903         }
3904
3905         /**
3906          * Get the revision ID of the previous revision
3907          *
3908          * @param $revId Int Revision ID. Get the revision that was before this one.
3909          * @param $flags Int Title::GAID_FOR_UPDATE
3910          * @return Int|Bool Old revision ID, or FALSE if none exists
3911          */
3912         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3913                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3914                 return $db->selectField( 'revision', 'rev_id',
3915                         array(
3916                                 'rev_page' => $this->getArticleID( $flags ),
3917                                 'rev_id < ' . intval( $revId )
3918                         ),
3919                         __METHOD__,
3920                         array( 'ORDER BY' => 'rev_id DESC' )
3921                 );
3922         }
3923
3924         /**
3925          * Get the revision ID of the next revision
3926          *
3927          * @param $revId Int Revision ID. Get the revision that was after this one.
3928          * @param $flags Int Title::GAID_FOR_UPDATE
3929          * @return Int|Bool Next revision ID, or FALSE if none exists
3930          */
3931         public function getNextRevisionID( $revId, $flags = 0 ) {
3932                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3933                 return $db->selectField( 'revision', 'rev_id',
3934                         array(
3935                                 'rev_page' => $this->getArticleID( $flags ),
3936                                 'rev_id > ' . intval( $revId )
3937                         ),
3938                         __METHOD__,
3939                         array( 'ORDER BY' => 'rev_id' )
3940                 );
3941         }
3942
3943         /**
3944          * Get the first revision of the page
3945          *
3946          * @param $flags Int Title::GAID_FOR_UPDATE
3947          * @return Revision|Null if page doesn't exist
3948          */
3949         public function getFirstRevision( $flags = 0 ) {
3950                 $pageId = $this->getArticleID( $flags );
3951                 if ( $pageId ) {
3952                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3953                         $row = $db->selectRow( 'revision', '*',
3954                                 array( 'rev_page' => $pageId ),
3955                                 __METHOD__,
3956                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3957                         );
3958                         if ( $row ) {
3959                                 return new Revision( $row );
3960                         }
3961                 }
3962                 return null;
3963         }
3964
3965         /**
3966          * Get the oldest revision timestamp of this page
3967          *
3968          * @param $flags Int Title::GAID_FOR_UPDATE
3969          * @return String: MW timestamp
3970          */
3971         public function getEarliestRevTime( $flags = 0 ) {
3972                 $rev = $this->getFirstRevision( $flags );
3973                 return $rev ? $rev->getTimestamp() : null;
3974         }
3975
3976         /**
3977          * Check if this is a new page
3978          *
3979          * @return bool
3980          */
3981         public function isNewPage() {
3982                 $dbr = wfGetDB( DB_SLAVE );
3983                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3984         }
3985
3986         /**
3987          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
3988          *
3989          * @return bool
3990          */
3991         public function isBigDeletion() {
3992                 global $wgDeleteRevisionsLimit;
3993
3994                 if ( !$wgDeleteRevisionsLimit ) {
3995                         return false;
3996                 }
3997
3998                 $revCount = $this->estimateRevisionCount();
3999                 return $revCount > $wgDeleteRevisionsLimit;
4000         }
4001
4002         /**
4003          * Get the  approximate revision count of this page.
4004          *
4005          * @return int
4006          */
4007         public function estimateRevisionCount() {
4008                 if ( !$this->exists() ) {
4009                         return 0;
4010                 }
4011
4012                 if ( $this->mEstimateRevisions === null ) {
4013                         $dbr = wfGetDB( DB_SLAVE );
4014                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4015                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4016                 }
4017
4018                 return $this->mEstimateRevisions;
4019         }
4020
4021         /**
4022          * Get the number of revisions between the given revision.
4023          * Used for diffs and other things that really need it.
4024          *
4025          * @param $old int|Revision Old revision or rev ID (first before range)
4026          * @param $new int|Revision New revision or rev ID (first after range)
4027          * @return Int Number of revisions between these revisions.
4028          */
4029         public function countRevisionsBetween( $old, $new ) {
4030                 if ( !( $old instanceof Revision ) ) {
4031                         $old = Revision::newFromTitle( $this, (int)$old );
4032                 }
4033                 if ( !( $new instanceof Revision ) ) {
4034                         $new = Revision::newFromTitle( $this, (int)$new );
4035                 }
4036                 if ( !$old || !$new ) {
4037                         return 0; // nothing to compare
4038                 }
4039                 $dbr = wfGetDB( DB_SLAVE );
4040                 return (int)$dbr->selectField( 'revision', 'count(*)',
4041                         array(
4042                                 'rev_page' => $this->getArticleID(),
4043                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4044                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4045                         ),
4046                         __METHOD__
4047                 );
4048         }
4049
4050         /**
4051          * Get the number of authors between the given revision IDs.
4052          * Used for diffs and other things that really need it.
4053          *
4054          * @param $old int|Revision Old revision or rev ID (first before range)
4055          * @param $new int|Revision New revision or rev ID (first after range)
4056          * @param $limit Int Maximum number of authors
4057          * @return Int Number of revision authors between these revisions.
4058          */
4059         public function countAuthorsBetween( $old, $new, $limit ) {
4060                 if ( !( $old instanceof Revision ) ) {
4061                         $old = Revision::newFromTitle( $this, (int)$old );
4062                 }
4063                 if ( !( $new instanceof Revision ) ) {
4064                         $new = Revision::newFromTitle( $this, (int)$new );
4065                 }
4066                 if ( !$old || !$new ) {
4067                         return 0; // nothing to compare
4068                 }
4069                 $dbr = wfGetDB( DB_SLAVE );
4070                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4071                         array(
4072                                 'rev_page' => $this->getArticleID(),
4073                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4074                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4075                         ), __METHOD__,
4076                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4077                 );
4078                 return (int)$dbr->numRows( $res );
4079         }
4080
4081         /**
4082          * Compare with another title.
4083          *
4084          * @param $title Title
4085          * @return Bool
4086          */
4087         public function equals( Title $title ) {
4088                 // Note: === is necessary for proper matching of number-like titles.
4089                 return $this->getInterwiki() === $title->getInterwiki()
4090                         && $this->getNamespace() == $title->getNamespace()
4091                         && $this->getDBkey() === $title->getDBkey();
4092         }
4093
4094         /**
4095          * Check if this title is a subpage of another title
4096          *
4097          * @param $title Title
4098          * @return Bool
4099          */
4100         public function isSubpageOf( Title $title ) {
4101                 return $this->getInterwiki() === $title->getInterwiki()
4102                         && $this->getNamespace() == $title->getNamespace()
4103                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4104         }
4105
4106         /**
4107          * Check if page exists.  For historical reasons, this function simply
4108          * checks for the existence of the title in the page table, and will
4109          * thus return false for interwiki links, special pages and the like.
4110          * If you want to know if a title can be meaningfully viewed, you should
4111          * probably call the isKnown() method instead.
4112          *
4113          * @return Bool
4114          */
4115         public function exists() {
4116                 return $this->getArticleID() != 0;
4117         }
4118
4119         /**
4120          * Should links to this title be shown as potentially viewable (i.e. as
4121          * "bluelinks"), even if there's no record by this title in the page
4122          * table?
4123          *
4124          * This function is semi-deprecated for public use, as well as somewhat
4125          * misleadingly named.  You probably just want to call isKnown(), which
4126          * calls this function internally.
4127          *
4128          * (ISSUE: Most of these checks are cheap, but the file existence check
4129          * can potentially be quite expensive.  Including it here fixes a lot of
4130          * existing code, but we might want to add an optional parameter to skip
4131          * it and any other expensive checks.)
4132          *
4133          * @return Bool
4134          */
4135         public function isAlwaysKnown() {
4136                 $isKnown = null;
4137
4138                 /**
4139                  * Allows overriding default behaviour for determining if a page exists.
4140                  * If $isKnown is kept as null, regular checks happen. If it's
4141                  * a boolean, this value is returned by the isKnown method.
4142                  *
4143                  * @since 1.20
4144                  *
4145                  * @param Title $title
4146                  * @param boolean|null $isKnown
4147                  */
4148                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4149
4150                 if ( !is_null( $isKnown ) ) {
4151                         return $isKnown;
4152                 }
4153
4154                 if ( $this->mInterwiki != '' ) {
4155                         return true;  // any interwiki link might be viewable, for all we know
4156                 }
4157
4158                 switch( $this->mNamespace ) {
4159                         case NS_MEDIA:
4160                         case NS_FILE:
4161                                 // file exists, possibly in a foreign repo
4162                                 return (bool)wfFindFile( $this );
4163                         case NS_SPECIAL:
4164                                 // valid special page
4165                                 return SpecialPageFactory::exists( $this->getDBkey() );
4166                         case NS_MAIN:
4167                                 // selflink, possibly with fragment
4168                                 return $this->mDbkeyform == '';
4169                         case NS_MEDIAWIKI:
4170                                 // known system message
4171                                 return $this->hasSourceText() !== false;
4172                         default:
4173                                 return false;
4174                 }
4175         }
4176
4177         /**
4178          * Does this title refer to a page that can (or might) be meaningfully
4179          * viewed?  In particular, this function may be used to determine if
4180          * links to the title should be rendered as "bluelinks" (as opposed to
4181          * "redlinks" to non-existent pages).
4182          * Adding something else to this function will cause inconsistency
4183          * since LinkHolderArray calls isAlwaysKnown() and does its own
4184          * page existence check.
4185          *
4186          * @return Bool
4187          */
4188         public function isKnown() {
4189                 return $this->isAlwaysKnown() || $this->exists();
4190         }
4191
4192         /**
4193          * Does this page have source text?
4194          *
4195          * @return Boolean
4196          */
4197         public function hasSourceText() {
4198                 if ( $this->exists() ) {
4199                         return true;
4200                 }
4201
4202                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4203                         // If the page doesn't exist but is a known system message, default
4204                         // message content will be displayed, same for language subpages-
4205                         // Use always content language to avoid loading hundreds of languages
4206                         // to get the link color.
4207                         global $wgContLang;
4208                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4209                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4210                         return $message->exists();
4211                 }
4212
4213                 return false;
4214         }
4215
4216         /**
4217          * Get the default message text or false if the message doesn't exist
4218          *
4219          * @return String or false
4220          */
4221         public function getDefaultMessageText() {
4222                 global $wgContLang;
4223
4224                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4225                         return false;
4226                 }
4227
4228                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4229                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4230
4231                 if ( $message->exists() ) {
4232                         return $message->plain();
4233                 } else {
4234                         return false;
4235                 }
4236         }
4237
4238         /**
4239          * Updates page_touched for this page; called from LinksUpdate.php
4240          *
4241          * @return Bool true if the update succeded
4242          */
4243         public function invalidateCache() {
4244                 if ( wfReadOnly() ) {
4245                         return false;
4246                 }
4247                 $dbw = wfGetDB( DB_MASTER );
4248                 $success = $dbw->update(
4249                         'page',
4250                         array( 'page_touched' => $dbw->timestamp() ),
4251                         $this->pageCond(),
4252                         __METHOD__
4253                 );
4254                 HTMLFileCache::clearFileCache( $this );
4255                 return $success;
4256         }
4257
4258         /**
4259          * Update page_touched timestamps and send squid purge messages for
4260          * pages linking to this title. May be sent to the job queue depending
4261          * on the number of links. Typically called on create and delete.
4262          */
4263         public function touchLinks() {
4264                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4265                 $u->doUpdate();
4266
4267                 if ( $this->getNamespace() == NS_CATEGORY ) {
4268                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4269                         $u->doUpdate();
4270                 }
4271         }
4272
4273         /**
4274          * Get the last touched timestamp
4275          *
4276          * @param $db DatabaseBase: optional db
4277          * @return String last-touched timestamp
4278          */
4279         public function getTouched( $db = null ) {
4280                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4281                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4282                 return $touched;
4283         }
4284
4285         /**
4286          * Get the timestamp when this page was updated since the user last saw it.
4287          *
4288          * @param $user User
4289          * @return String|Null
4290          */
4291         public function getNotificationTimestamp( $user = null ) {
4292                 global $wgUser, $wgShowUpdatedMarker;
4293                 // Assume current user if none given
4294                 if ( !$user ) {
4295                         $user = $wgUser;
4296                 }
4297                 // Check cache first
4298                 $uid = $user->getId();
4299                 // avoid isset here, as it'll return false for null entries
4300                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4301                         return $this->mNotificationTimestamp[$uid];
4302                 }
4303                 if ( !$uid || !$wgShowUpdatedMarker ) {
4304                         return $this->mNotificationTimestamp[$uid] = false;
4305                 }
4306                 // Don't cache too much!
4307                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4308                         $this->mNotificationTimestamp = array();
4309                 }
4310                 $dbr = wfGetDB( DB_SLAVE );
4311                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4312                         'wl_notificationtimestamp',
4313                         array( 'wl_namespace' => $this->getNamespace(),
4314                                 'wl_title' => $this->getDBkey(),
4315                                 'wl_user' => $user->getId()
4316                         ),
4317                         __METHOD__
4318                 );
4319                 return $this->mNotificationTimestamp[$uid];
4320         }
4321
4322         /**
4323          * Generate strings used for xml 'id' names in monobook tabs
4324          *
4325          * @param $prepend string defaults to 'nstab-'
4326          * @return String XML 'id' name
4327          */
4328         public function getNamespaceKey( $prepend = 'nstab-' ) {
4329                 global $wgContLang;
4330                 // Gets the subject namespace if this title
4331                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4332                 // Checks if cononical namespace name exists for namespace
4333                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4334                         // Uses canonical namespace name
4335                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4336                 } else {
4337                         // Uses text of namespace
4338                         $namespaceKey = $this->getSubjectNsText();
4339                 }
4340                 // Makes namespace key lowercase
4341                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4342                 // Uses main
4343                 if ( $namespaceKey == '' ) {
4344                         $namespaceKey = 'main';
4345                 }
4346                 // Changes file to image for backwards compatibility
4347                 if ( $namespaceKey == 'file' ) {
4348                         $namespaceKey = 'image';
4349                 }
4350                 return $prepend . $namespaceKey;
4351         }
4352
4353         /**
4354          * Get all extant redirects to this Title
4355          *
4356          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4357          * @return Array of Title redirects to this title
4358          */
4359         public function getRedirectsHere( $ns = null ) {
4360                 $redirs = array();
4361
4362                 $dbr = wfGetDB( DB_SLAVE );
4363                 $where = array(
4364                         'rd_namespace' => $this->getNamespace(),
4365                         'rd_title' => $this->getDBkey(),
4366                         'rd_from = page_id'
4367                 );
4368                 if ( !is_null( $ns ) ) {
4369                         $where['page_namespace'] = $ns;
4370                 }
4371
4372                 $res = $dbr->select(
4373                         array( 'redirect', 'page' ),
4374                         array( 'page_namespace', 'page_title' ),
4375                         $where,
4376                         __METHOD__
4377                 );
4378
4379                 foreach ( $res as $row ) {
4380                         $redirs[] = self::newFromRow( $row );
4381                 }
4382                 return $redirs;
4383         }
4384
4385         /**
4386          * Check if this Title is a valid redirect target
4387          *
4388          * @return Bool
4389          */
4390         public function isValidRedirectTarget() {
4391                 global $wgInvalidRedirectTargets;
4392
4393                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4394                 if ( $this->isSpecial( 'Userlogout' ) ) {
4395                         return false;
4396                 }
4397
4398                 foreach ( $wgInvalidRedirectTargets as $target ) {
4399                         if ( $this->isSpecial( $target ) ) {
4400                                 return false;
4401                         }
4402                 }
4403
4404                 return true;
4405         }
4406
4407         /**
4408          * Get a backlink cache object
4409          *
4410          * @return BacklinkCache
4411          */
4412         function getBacklinkCache() {
4413                 if ( is_null( $this->mBacklinkCache ) ) {
4414                         $this->mBacklinkCache = new BacklinkCache( $this );
4415                 }
4416                 return $this->mBacklinkCache;
4417         }
4418
4419         /**
4420          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4421          *
4422          * @return Boolean
4423          */
4424         public function canUseNoindex() {
4425                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4426
4427                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4428                         ? $wgContentNamespaces
4429                         : $wgExemptFromUserRobotsControl;
4430
4431                 return !in_array( $this->mNamespace, $bannedNamespaces );
4432
4433         }
4434
4435         /**
4436          * Returns the raw sort key to be used for categories, with the specified
4437          * prefix.  This will be fed to Collation::getSortKey() to get a
4438          * binary sortkey that can be used for actual sorting.
4439          *
4440          * @param $prefix string The prefix to be used, specified using
4441          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4442          *   prefix.
4443          * @return string
4444          */
4445         public function getCategorySortkey( $prefix = '' ) {
4446                 $unprefixed = $this->getText();
4447
4448                 // Anything that uses this hook should only depend
4449                 // on the Title object passed in, and should probably
4450                 // tell the users to run updateCollations.php --force
4451                 // in order to re-sort existing category relations.
4452                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4453                 if ( $prefix !== '' ) {
4454                         # Separate with a line feed, so the unprefixed part is only used as
4455                         # a tiebreaker when two pages have the exact same prefix.
4456                         # In UCA, tab is the only character that can sort above LF
4457                         # so we strip both of them from the original prefix.
4458                         $prefix = strtr( $prefix, "\n\t", '  ' );
4459                         return "$prefix\n$unprefixed";
4460                 }
4461                 return $unprefixed;
4462         }
4463
4464         /**
4465          * Get the language in which the content of this page is written.
4466          * Defaults to $wgContLang, but in certain cases it can be e.g.
4467          * $wgLang (such as special pages, which are in the user language).
4468          *
4469          * @since 1.18
4470          * @return object Language
4471          */
4472         public function getPageLanguage() {
4473                 global $wgLang;
4474                 if ( $this->isSpecialPage() ) {
4475                         // special pages are in the user language
4476                         return $wgLang;
4477                 } elseif ( $this->isCssOrJsPage() || $this->isCssJsSubpage() ) {
4478                         // css/js should always be LTR and is, in fact, English
4479                         return wfGetLangObj( 'en' );
4480                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4481                         // Parse mediawiki messages with correct target language
4482                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4483                         return wfGetLangObj( $lang );
4484                 }
4485                 global $wgContLang;
4486                 // If nothing special, it should be in the wiki content language
4487                 $pageLang = $wgContLang;
4488                 // Hook at the end because we don't want to override the above stuff
4489                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4490                 return wfGetLangObj( $pageLang );
4491         }
4492 }