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; # FIXME: whene3ver page_latest is updated, also update page_content_model
 275             if ( isset( $row->page_content_model ) )
 276                 $this->mContentModelName = $row->page_content_model;
 277             else
 278                 $this->mContentModelName = null; # initialized lazily in getContentModelName()
 279                 } else { // page not found
 280                         $this->mArticleID = 0;
 281                         $this->mLength = 0;
 282                         $this->mRedirect = false;
 283                         $this->mLatestID = 0;
 284             $this->mContentModelName = null; # initialized lazily in getContentModelName()
 285                 }
 286         }
 287
 288         /**
 289          * Create a new Title from a namespace index and a DB key.
 290          * It's assumed that $ns and $title are *valid*, for instance when
 291          * they came directly from the database or a special page name.
 292          * For convenience, spaces are converted to underscores so that
 293          * eg user_text fields can be used directly.
 294          *
 295          * @param $ns Int the namespace of the article
 296          * @param $title String the unprefixed database key form
 297          * @param $fragment String the link fragment (after the "#")
 298          * @param $interwiki String the interwiki prefix
 299          * @return Title the new object
 300          */
 301         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 302                 $t = new Title();
 303                 $t->mInterwiki = $interwiki;
 304                 $t->mFragment = $fragment;
 305                 $t->mNamespace = $ns = intval( $ns );
 306                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 307                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 308                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 309                 $t->mTextform = str_replace( '_', ' ', $title );
 310         $t->mContentModelName = null; # initialized lazily in getContentModelName()
 311                 return $t;
 312         }
 313
 314         /**
 315          * Create a new Title from a namespace index and a DB key.
 316          * The parameters will be checked for validity, which is a bit slower
 317          * than makeTitle() but safer for user-provided data.
 318          *
 319          * @param $ns Int the namespace of the article
 320          * @param $title String database key form
 321          * @param $fragment String the link fragment (after the "#")
 322          * @param $interwiki String interwiki prefix
 323          * @return Title the new object, or NULL on an error
 324          */
 325         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 326                 $t = new Title();
 327                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 328                 if ( $t->secureAndSplit() ) {
 329                         return $t;
 330                 } else {
 331                         return null;
 332                 }
 333         }
 334
 335         /**
 336          * Create a new Title for the Main Page
 337          *
 338          * @return Title the new object
 339          */
 340         public static function newMainPage() {
 341                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 342                 // Don't give fatal errors if the message is broken
 343                 if ( !$title ) {
 344                         $title = Title::newFromText( 'Main Page' );
 345                 }
 346                 return $title;
 347         }
 348
 349         /**
 350          * Extract a redirect destination from a string and return the
 351          * Title, or null if the text doesn't contain a valid redirect
 352          * This will only return the very next target, useful for
 353          * the redirect table and other checks that don't need full recursion
 354          *
 355          * @param $text String: Text with possible redirect
 356          * @return Title: The corresponding Title
 357          */
 358         public static function newFromRedirect( $text ) {
 359                 return self::newFromRedirectInternal( $text );
 360         }
 361
 362         /**
 363          * Extract a redirect destination from a string and return the
 364          * Title, or null if the text doesn't contain a valid redirect
 365          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 366          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 367          *
 368          * @param $text String Text with possible redirect
 369          * @return Title
 370          */
 371         public static function newFromRedirectRecurse( $text ) {
 372                 $titles = self::newFromRedirectArray( $text );
 373                 return $titles ? array_pop( $titles ) : null;
 374         }
 375
 376         /**
 377          * Extract a redirect destination from a string and return an
 378          * array of Titles, or null if the text doesn't contain a valid redirect
 379          * The last element in the array is the final destination after all redirects
 380          * have been resolved (up to $wgMaxRedirects times)
 381          *
 382          * @param $text String Text with possible redirect
 383          * @return Array of Titles, with the destination last
 384          */
 385         public static function newFromRedirectArray( $text ) {
 386                 global $wgMaxRedirects;
 387                 $title = self::newFromRedirectInternal( $text );
 388                 if ( is_null( $title ) ) {
 389                         return null;
 390                 }
 391                 // recursive check to follow double redirects
 392                 $recurse = $wgMaxRedirects;
 393                 $titles = array( $title );
 394                 while ( --$recurse > 0 ) {
 395                         if ( $title->isRedirect() ) {
 396                                 $page = WikiPage::factory( $title );
 397                                 $newtitle = $page->getRedirectTarget();
 398                         } else {
 399                                 break;
 400                         }
 401                         // Redirects to some special pages are not permitted
 402                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 403                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 404                                 $title = $newtitle;
 405                                 $titles[] = $newtitle;
 406                         } else {
 407                                 break;
 408                         }
 409                 }
 410                 return $titles;
 411         }
 412
 413         /**
 414          * Really extract the redirect destination
 415          * Do not call this function directly, use one of the newFromRedirect* functions above
 416          *
 417          * @param $text String Text with possible redirect
 418          * @return Title
 419          */
 420         protected static function newFromRedirectInternal( $text ) {
 421                 global $wgMaxRedirects;
 422                 if ( $wgMaxRedirects < 1 ) {
 423                         //redirects are disabled, so quit early
 424                         return null;
 425                 }
 426                 $redir = MagicWord::get( 'redirect' );
 427                 $text = trim( $text );
 428                 if ( $redir->matchStartAndRemove( $text ) ) {
 429                         // Extract the first link and see if it's usable
 430                         // Ensure that it really does come directly after #REDIRECT
 431                         // Some older redirects included a colon, so don't freak about that!
 432                         $m = array();
 433                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 434                                 // Strip preceding colon used to "escape" categories, etc.
 435                                 // and URL-decode links
 436                                 if ( strpos( $m[1], '%' ) !== false ) {
 437                                         // Match behavior of inline link parsing here;
 438                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 439                                 }
 440                                 $title = Title::newFromText( $m[1] );
 441                                 // If the title is a redirect to bad special pages or is invalid, return null
 442                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 443                                         return null;
 444                                 }
 445                                 return $title;
 446                         }
 447                 }
 448                 return null;
 449         }
 450
 451         /**
 452          * Get the prefixed DB key associated with an ID
 453          *
 454          * @param $id Int the page_id of the article
 455          * @return Title an object representing the article, or NULL if no such article was found
 456          */
 457         public static function nameOf( $id ) {
 458                 $dbr = wfGetDB( DB_SLAVE );
 459
 460                 $s = $dbr->selectRow(
 461                         'page',
 462                         array( 'page_namespace', 'page_title' ),
 463                         array( 'page_id' => $id ),
 464                         __METHOD__
 465                 );
 466                 if ( $s === false ) {
 467                         return null;
 468                 }
 469
 470                 $n = self::makeName( $s->page_namespace, $s->page_title );
 471                 return $n;
 472         }
 473
 474         /**
 475          * Get a regex character class describing the legal characters in a link
 476          *
 477          * @return String the list of characters, not delimited
 478          */
 479         public static function legalChars() {
 480                 global $wgLegalTitleChars;
 481                 return $wgLegalTitleChars;
 482         }
 483
 484         /**
 485          * Returns a simple regex that will match on characters and sequences invalid in titles.
 486          * Note that this doesn't pick up many things that could be wrong with titles, but that
 487          * replacing this regex with something valid will make many titles valid.
 488          *
 489          * @return String regex string
 490          */
 491         static function getTitleInvalidRegex() {
 492                 static $rxTc = false;
 493                 if ( !$rxTc ) {
 494                         # Matching titles will be held as illegal.
 495                         $rxTc = '/' .
 496                                 # Any character not allowed is forbidden...
 497                                 '[^' . self::legalChars() . ']' .
 498                                 # URL percent encoding sequences interfere with the ability
 499                                 # to round-trip titles -- you can't link to them consistently.
 500                                 '|%[0-9A-Fa-f]{2}' .
 501                                 # XML/HTML character references produce similar issues.
 502                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 503                                 '|&#[0-9]+;' .
 504                                 '|&#x[0-9A-Fa-f]+;' .
 505                                 '/S';
 506                 }
 507
 508                 return $rxTc;
 509         }
 510
 511         /**
 512          * Get a string representation of a title suitable for
 513          * including in a search index
 514          *
 515          * @param $ns Int a namespace index
 516          * @param $title String text-form main part
 517          * @return String a stripped-down title string ready for the search index
 518          */
 519         public static function indexTitle( $ns, $title ) {
 520                 global $wgContLang;
 521
 522                 $lc = SearchEngine::legalSearchChars() . '&#;';
 523                 $t = $wgContLang->normalizeForSearch( $title );
 524                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 525                 $t = $wgContLang->lc( $t );
 526
 527                 # Handle 's, s'
 528                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 529                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 530
 531                 $t = preg_replace( "/\\s+/", ' ', $t );
 532
 533                 if ( $ns == NS_FILE ) {
 534                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 535                 }
 536                 return trim( $t );
 537         }
 538
 539         /**
 540          * Make a prefixed DB key from a DB key and a namespace index
 541          *
 542          * @param $ns Int numerical representation of the namespace
 543          * @param $title String the DB key form the title
 544          * @param $fragment String The link fragment (after the "#")
 545          * @param $interwiki String The interwiki prefix
 546          * @return String the prefixed form of the title
 547          */
 548         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 549                 global $wgContLang;
 550
 551                 $namespace = $wgContLang->getNsText( $ns );
 552                 $name = $namespace == '' ? $title : "$namespace:$title";
 553                 if ( strval( $interwiki ) != '' ) {
 554                         $name = "$interwiki:$name";
 555                 }
 556                 if ( strval( $fragment ) != '' ) {
 557                         $name .= '#' . $fragment;
 558                 }
 559                 return $name;
 560         }
 561
 562         /**
 563          * Escape a text fragment, say from a link, for a URL
 564          *
 565          * @param $fragment string containing a URL or link fragment (after the "#")
 566          * @return String: escaped string
 567          */
 568         static function escapeFragmentForURL( $fragment ) {
 569                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 570                 # fragments appear not to work in IE (at least up to 7) or in at least
 571                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 572                 # to care if they aren't encoded.
 573                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 574         }
 575
 576         /**
 577          * Callback for usort() to do title sorts by (namespace, title)
 578          *
 579          * @param $a Title
 580          * @param $b Title
 581          *
 582          * @return Integer: result of string comparison, or namespace comparison
 583          */
 584         public static function compare( $a, $b ) {
 585                 if ( $a->getNamespace() == $b->getNamespace() ) {
 586                         return strcmp( $a->getText(), $b->getText() );
 587                 } else {
 588                         return $a->getNamespace() - $b->getNamespace();
 589                 }
 590         }
 591
 592         /**
 593          * Determine whether the object refers to a page within
 594          * this project.
 595          *
 596          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 597          */
 598         public function isLocal() {
 599                 if ( $this->mInterwiki != '' ) {
 600                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 601                 } else {
 602                         return true;
 603                 }
 604         }
 605
 606         /**
 607          * Is this Title interwiki?
 608          *
 609          * @return Bool
 610          */
 611         public function isExternal() {
 612                 return ( $this->mInterwiki != '' );
 613         }
 614
 615         /**
 616          * Get the interwiki prefix (or null string)
 617          *
 618          * @return String Interwiki prefix
 619          */
 620         public function getInterwiki() {
 621                 return $this->mInterwiki;
 622         }
 623
 624         /**
 625          * Determine whether the object refers to a page within
 626          * this project and is transcludable.
 627          *
 628          * @return Bool TRUE if this is transcludable
 629          */
 630         public function isTrans() {
 631                 if ( $this->mInterwiki == '' ) {
 632                         return false;
 633                 }
 634
 635                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 636         }
 637
 638         /**
 639          * Returns the DB name of the distant wiki which owns the object.
 640          *
 641          * @return String the DB name
 642          */
 643         public function getTransWikiID() {
 644                 if ( $this->mInterwiki == '' ) {
 645                         return false;
 646                 }
 647
 648                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 649         }
 650
 651         /**
 652          * Get the text form (spaces not underscores) of the main part
 653          *
 654          * @return String Main part of the title
 655          */
 656         public function getText() {
 657                 return $this->mTextform;
 658         }
 659
 660         /**
 661          * Get the URL-encoded form of the main part
 662          *
 663          * @return String Main part of the title, URL-encoded
 664          */
 665         public function getPartialURL() {
 666                 return $this->mUrlform;
 667         }
 668
 669         /**
 670          * Get the main part with underscores
 671          *
 672          * @return String: Main part of the title, with underscores
 673          */
 674         public function getDBkey() {
 675                 return $this->mDbkeyform;
 676         }
 677
 678         /**
 679          * Get the DB key with the initial letter case as specified by the user
 680          *
 681          * @return String DB key
 682          */
 683         function getUserCaseDBKey() {
 684                 return $this->mUserCaseDBKey;
 685         }
 686
 687         /**
 688          * Get the namespace index, i.e. one of the NS_xxxx constants.
 689          *
 690          * @return Integer: Namespace index
 691          */
 692         public function getNamespace() {
 693                 return $this->mNamespace;
 694         }
 695
 696     /**
 697      * Get the page's content model name
 698      *
 699      * @return Integer: Namespace index
 700      */
 701     public function getContentModelName() {
 702         if ( empty( $this->mContentModelName ) ) {
 703             $this->mContentModelName = ContentHandler::getDefaultModelFor( $this );
 704         }
 705
 706         return $this->mContentModelName;
 707     }
 708
 709     /**
 710      * Conveniance method for checking a title's content model name
 711      *
 712      * @param $name
 713      * @return true if $this->getContentModelName() == $name
 714      */
 715     public function hasContentModel( $name ) {
 716         return $this->getContentModelName() == $name;
 717     }
 718
 719         /**
 720          * Get the namespace text
 721          *
 722          * @return String: Namespace text
 723          */
 724         public function getNsText() {
 725                 global $wgContLang;
 726
 727                 if ( $this->mInterwiki != '' ) {
 728                         // This probably shouldn't even happen. ohh man, oh yuck.
 729                         // But for interwiki transclusion it sometimes does.
 730                         // Shit. Shit shit shit.
 731                         //
 732                         // Use the canonical namespaces if possible to try to
 733                         // resolve a foreign namespace.
 734                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 735                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 736                         }
 737                 }
 738
 739                 // Strip off subpages
 740                 $pagename = $this->getText();
 741                 if ( strpos( $pagename, '/' ) !== false ) {
 742                         list( $username , ) = explode( '/', $pagename, 2 );
 743                 } else {
 744                         $username = $pagename;
 745                 }
 746
 747                 if ( $wgContLang->needsGenderDistinction() &&
 748                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 749                         $gender = GenderCache::singleton()->getGenderOf( $username, __METHOD__ );
 750                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 751                 }
 752
 753                 return $wgContLang->getNsText( $this->mNamespace );
 754         }
 755
 756         /**
 757          * Get the namespace text of the subject (rather than talk) page
 758          *
 759          * @return String Namespace text
 760          */
 761         public function getSubjectNsText() {
 762                 global $wgContLang;
 763                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 764         }
 765
 766         /**
 767          * Get the namespace text of the talk page
 768          *
 769          * @return String Namespace text
 770          */
 771         public function getTalkNsText() {
 772                 global $wgContLang;
 773                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 774         }
 775
 776         /**
 777          * Could this title have a corresponding talk page?
 778          *
 779          * @return Bool TRUE or FALSE
 780          */
 781         public function canTalk() {
 782                 return( MWNamespace::canTalk( $this->mNamespace ) );
 783         }
 784
 785         /**
 786          * Is this in a namespace that allows actual pages?
 787          *
 788          * @return Bool
 789          * @internal note -- uses hardcoded namespace index instead of constants
 790          */
 791         public function canExist() {
 792                 return $this->mNamespace >= NS_MAIN;
 793         }
 794
 795         /**
 796          * Can this title be added to a user's watchlist?
 797          *
 798          * @return Bool TRUE or FALSE
 799          */
 800         public function isWatchable() {
 801                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 802         }
 803
 804         /**
 805          * Returns true if this is a special page.
 806          *
 807          * @return boolean
 808          */
 809         public function isSpecialPage() {
 810                 return $this->getNamespace() == NS_SPECIAL;
 811         }
 812
 813         /**
 814          * Returns true if this title resolves to the named special page
 815          *
 816          * @param $name String The special page name
 817          * @return boolean
 818          */
 819         public function isSpecial( $name ) {
 820                 if ( $this->isSpecialPage() ) {
 821                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 822                         if ( $name == $thisName ) {
 823                                 return true;
 824                         }
 825                 }
 826                 return false;
 827         }
 828
 829         /**
 830          * If the Title refers to a special page alias which is not the local default, resolve
 831          * the alias, and localise the name as necessary.  Otherwise, return $this
 832          *
 833          * @return Title
 834          */
 835         public function fixSpecialName() {
 836                 if ( $this->isSpecialPage() ) {
 837                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 838                         if ( $canonicalName ) {
 839                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 840                                 if ( $localName != $this->mDbkeyform ) {
 841                                         return Title::makeTitle( NS_SPECIAL, $localName );
 842                                 }
 843                         }
 844                 }
 845                 return $this;
 846         }
 847
 848         /**
 849          * Returns true if the title is inside the specified namespace.
 850          *
 851          * Please make use of this instead of comparing to getNamespace()
 852          * This function is much more resistant to changes we may make
 853          * to namespaces than code that makes direct comparisons.
 854          * @param $ns int The namespace
 855          * @return bool
 856          * @since 1.19
 857          */
 858         public function inNamespace( $ns ) {
 859                 return MWNamespace::equals( $this->getNamespace(), $ns );
 860         }
 861
 862         /**
 863          * Returns true if the title is inside one of the specified namespaces.
 864          *
 865          * @param ...$namespaces The namespaces to check for
 866          * @return bool
 867          * @since 1.19
 868          */
 869         public function inNamespaces( /* ... */ ) {
 870                 $namespaces = func_get_args();
 871                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 872                         $namespaces = $namespaces[0];
 873                 }
 874
 875                 foreach ( $namespaces as $ns ) {
 876                         if ( $this->inNamespace( $ns ) ) {
 877                                 return true;
 878                         }
 879                 }
 880
 881                 return false;
 882         }
 883
 884         /**
 885          * Returns true if the title has the same subject namespace as the
 886          * namespace specified.
 887          * For example this method will take NS_USER and return true if namespace
 888          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 889          * as their subject namespace.
 890          *
 891          * This is MUCH simpler than individually testing for equivilance
 892          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 893          * @since 1.19
 894          * @return bool
 895          */
 896         public function hasSubjectNamespace( $ns ) {
 897                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 898         }
 899
 900         /**
 901          * Is this Title in a namespace which contains content?
 902          * In other words, is this a content page, for the purposes of calculating
 903          * statistics, etc?
 904          *
 905          * @return Boolean
 906          */
 907         public function isContentPage() {
 908                 return MWNamespace::isContent( $this->getNamespace() );
 909         }
 910
 911         /**
 912          * Would anybody with sufficient privileges be able to move this page?
 913          * Some pages just aren't movable.
 914          *
 915          * @return Bool TRUE or FALSE
 916          */
 917         public function isMovable() {
 918                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 919                         // Interwiki title or immovable namespace. Hooks don't get to override here
 920                         return false;
 921                 }
 922
 923                 $result = true;
 924                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 925                 return $result;
 926         }
 927
 928         /**
 929          * Is this the mainpage?
 930          * @note Title::newFromText seams to be sufficiently optimized by the title
 931          * cache that we don't need to over-optimize by doing direct comparisons and
 932          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 933          * ends up reporting something differently than $title->isMainPage();
 934          *
 935          * @since 1.18
 936          * @return Bool
 937          */
 938         public function isMainPage() {
 939                 return $this->equals( Title::newMainPage() );
 940         }
 941
 942         /**
 943          * Is this a subpage?
 944          *
 945          * @return Bool
 946          */
 947         public function isSubpage() {
 948                 return MWNamespace::hasSubpages( $this->mNamespace )
 949                         ? strpos( $this->getText(), '/' ) !== false
 950                         : false;
 951         }
 952
 953         /**
 954          * Is this a conversion table for the LanguageConverter?
 955          *
 956          * @return Bool
 957          */
 958         public function isConversionTable() {
 959                 return $this->getNamespace() == NS_MEDIAWIKI &&
 960                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 961         }
 962
 963         /**
 964          * Does that page contain wikitext, or it is JS, CSS or whatever?
 965          *
 966          * @return Bool
 967          */
 968         public function isWikitextPage() {
 969                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 970         }
 971
 972         /**
 973          * Could this page contain custom CSS or JavaScript for the global UI.
 974      * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 975      * or CONTENT_MODEL_JAVASCRIPT.
 976      *
 977      * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 978          *
 979          * @return Bool
 980          */
 981         public function isCssOrJsPage() {
 982         $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 983             && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 984                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 985
 986         #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 987         #      hook funktions can force this method to return true even outside the mediawiki namespace.
 988
 989         wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
 990
 991         return $isCssOrJsPage;
 992         }
 993
 994         /**
 995          * Is this a .css or .js subpage of a user page?
 996          * @return Bool
 997          */
 998         public function isCssJsSubpage() {
 999                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1000             && $this->isCssOrJsPage() );
1001         }
1002
1003         /**
1004          * Trim down a .css or .js subpage title to get the corresponding skin name
1005          *
1006          * @return string containing skin name from .css or .js subpage title
1007          */
1008         public function getSkinFromCssJsSubpage() {
1009                 $subpage = explode( '/', $this->mTextform );
1010                 $subpage = $subpage[ count( $subpage ) - 1 ];
1011                 $lastdot = strrpos( $subpage, '.' );
1012                 if ( $lastdot === false )
1013                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1014                 return substr( $subpage, 0, $lastdot );
1015         }
1016
1017         /**
1018          * Is this a .css subpage of a user page?
1019          *
1020          * @return Bool
1021          */
1022         public function isCssSubpage() {
1023         return ( NS_USER == $this->mNamespace && $this->isSubpage()
1024             && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1025         }
1026
1027         /**
1028          * Is this a .js subpage of a user page?
1029          *
1030          * @return Bool
1031          */
1032         public function isJsSubpage() {
1033         return ( NS_USER == $this->mNamespace && $this->isSubpage()
1034             && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1035         }
1036
1037         /**
1038          * Is this a talk page of some sort?
1039          *
1040          * @return Bool
1041          */
1042         public function isTalkPage() {
1043                 return MWNamespace::isTalk( $this->getNamespace() );
1044         }
1045
1046         /**
1047          * Get a Title object associated with the talk page of this article
1048          *
1049          * @return Title the object for the talk page
1050          */
1051         public function getTalkPage() {
1052                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1053         }
1054
1055         /**
1056          * Get a title object associated with the subject page of this
1057          * talk page
1058          *
1059          * @return Title the object for the subject page
1060          */
1061         public function getSubjectPage() {
1062                 // Is this the same title?
1063                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1064                 if ( $this->getNamespace() == $subjectNS ) {
1065                         return $this;
1066                 }
1067                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1068         }
1069
1070         /**
1071          * Get the default namespace index, for when there is no namespace
1072          *
1073          * @return Int Default namespace index
1074          */
1075         public function getDefaultNamespace() {
1076                 return $this->mDefaultNamespace;
1077         }
1078
1079         /**
1080          * Get title for search index
1081          *
1082          * @return String a stripped-down title string ready for the
1083          *  search index
1084          */
1085         public function getIndexTitle() {
1086                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1087         }
1088
1089         /**
1090          * Get the Title fragment (i.e.\ the bit after the #) in text form
1091          *
1092          * @return String Title fragment
1093          */
1094         public function getFragment() {
1095                 return $this->mFragment;
1096         }
1097
1098         /**
1099          * Get the fragment in URL form, including the "#" character if there is one
1100          * @return String Fragment in URL form
1101          */
1102         public function getFragmentForURL() {
1103                 if ( $this->mFragment == '' ) {
1104                         return '';
1105                 } else {
1106                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1107                 }
1108         }
1109
1110         /**
1111          * Set the fragment for this title. Removes the first character from the
1112          * specified fragment before setting, so it assumes you're passing it with
1113          * an initial "#".
1114          *
1115          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1116          * Still in active use privately.
1117          *
1118          * @param $fragment String text
1119          */
1120         public function setFragment( $fragment ) {
1121                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1122         }
1123
1124         /**
1125          * Prefix some arbitrary text with the namespace or interwiki prefix
1126          * of this object
1127          *
1128          * @param $name String the text
1129          * @return String the prefixed text
1130          * @private
1131          */
1132         private function prefix( $name ) {
1133                 $p = '';
1134                 if ( $this->mInterwiki != '' ) {
1135                         $p = $this->mInterwiki . ':';
1136                 }
1137
1138                 if ( 0 != $this->mNamespace ) {
1139                         $p .= $this->getNsText() . ':';
1140                 }
1141                 return $p . $name;
1142         }
1143
1144         /**
1145          * Get the prefixed database key form
1146          *
1147          * @return String the prefixed title, with underscores and
1148          *  any interwiki and namespace prefixes
1149          */
1150         public function getPrefixedDBkey() {
1151                 $s = $this->prefix( $this->mDbkeyform );
1152                 $s = str_replace( ' ', '_', $s );
1153                 return $s;
1154         }
1155
1156         /**
1157          * Get the prefixed title with spaces.
1158          * This is the form usually used for display
1159          *
1160          * @return String the prefixed title, with spaces
1161          */
1162         public function getPrefixedText() {
1163                 // @todo FIXME: Bad usage of empty() ?
1164                 if ( empty( $this->mPrefixedText ) ) {
1165                         $s = $this->prefix( $this->mTextform );
1166                         $s = str_replace( '_', ' ', $s );
1167                         $this->mPrefixedText = $s;
1168                 }
1169                 return $this->mPrefixedText;
1170         }
1171
1172         /**
1173          * Return a string representation of this title
1174          *
1175          * @return String representation of this title
1176          */
1177         public function __toString() {
1178                 return $this->getPrefixedText();
1179         }
1180
1181         /**
1182          * Get the prefixed title with spaces, plus any fragment
1183          * (part beginning with '#')
1184          *
1185          * @return String the prefixed title, with spaces and the fragment, including '#'
1186          */
1187         public function getFullText() {
1188                 $text = $this->getPrefixedText();
1189                 if ( $this->mFragment != '' ) {
1190                         $text .= '#' . $this->mFragment;
1191                 }
1192                 return $text;
1193         }
1194
1195         /**
1196          * Get the base page name, i.e. the leftmost part before any slashes
1197          *
1198          * @return String Base name
1199          */
1200         public function getBaseText() {
1201                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1202                         return $this->getText();
1203                 }
1204
1205                 $parts = explode( '/', $this->getText() );
1206                 # Don't discard the real title if there's no subpage involved
1207                 if ( count( $parts ) > 1 ) {
1208                         unset( $parts[count( $parts ) - 1] );
1209                 }
1210                 return implode( '/', $parts );
1211         }
1212
1213         /**
1214          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1215          *
1216          * @return String Subpage name
1217          */
1218         public function getSubpageText() {
1219                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1220                         return( $this->mTextform );
1221                 }
1222                 $parts = explode( '/', $this->mTextform );
1223                 return( $parts[count( $parts ) - 1] );
1224         }
1225
1226         /**
1227          * Get the HTML-escaped displayable text form.
1228          * Used for the title field in <a> tags.
1229          *
1230          * @return String the text, including any prefixes
1231          */
1232         public function getEscapedText() {
1233                 wfDeprecated( __METHOD__, '1.19' );
1234                 return htmlspecialchars( $this->getPrefixedText() );
1235         }
1236
1237         /**
1238          * Get a URL-encoded form of the subpage text
1239          *
1240          * @return String URL-encoded subpage name
1241          */
1242         public function getSubpageUrlForm() {
1243                 $text = $this->getSubpageText();
1244                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1245                 return( $text );
1246         }
1247
1248         /**
1249          * Get a URL-encoded title (not an actual URL) including interwiki
1250          *
1251          * @return String the URL-encoded form
1252          */
1253         public function getPrefixedURL() {
1254                 $s = $this->prefix( $this->mDbkeyform );
1255                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1256                 return $s;
1257         }
1258
1259         /**
1260          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1261          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1262          * second argument named variant. This was deprecated in favor
1263          * of passing an array of option with a "variant" key
1264          * Once $query2 is removed for good, this helper can be dropped
1265          * andthe wfArrayToCGI moved to getLocalURL();
1266          *
1267          * @since 1.19 (r105919)
1268          * @return String
1269          */
1270         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1271                 if( $query2 !== false ) {
1272                         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" );
1273                 }
1274                 if ( is_array( $query ) ) {
1275                         $query = wfArrayToCGI( $query );
1276                 }
1277                 if ( $query2 ) {
1278                         if ( is_string( $query2 ) ) {
1279                                 // $query2 is a string, we will consider this to be
1280                                 // a deprecated $variant argument and add it to the query
1281                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1282                         } else {
1283                                 $query2 = wfArrayToCGI( $query2 );
1284                         }
1285                         // If we have $query content add a & to it first
1286                         if ( $query ) {
1287                                 $query .= '&';
1288                         }
1289                         // Now append the queries together
1290                         $query .= $query2;
1291                 }
1292                 return $query;
1293         }
1294
1295         /**
1296          * Get a real URL referring to this title, with interwiki link and
1297          * fragment
1298          *
1299          * See getLocalURL for the arguments.
1300          *
1301          * @see self::getLocalURL
1302          * @return String the URL
1303          */
1304         public function getFullURL( $query = '', $query2 = false ) {
1305                 $query = self::fixUrlQueryArgs( $query, $query2 );
1306
1307                 # Hand off all the decisions on urls to getLocalURL
1308                 $url = $this->getLocalURL( $query );
1309
1310                 # Expand the url to make it a full url. Note that getLocalURL has the
1311                 # potential to output full urls for a variety of reasons, so we use
1312                 # wfExpandUrl instead of simply prepending $wgServer
1313                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1314
1315                 # Finally, add the fragment.
1316                 $url .= $this->getFragmentForURL();
1317
1318                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1319                 return $url;
1320         }
1321
1322         /**
1323          * Get a URL with no fragment or server name.  If this page is generated
1324          * with action=render, $wgServer is prepended.
1325          *
1326
1327          * @param $query string|array an optional query string,
1328          *   not used for interwiki     links. Can be specified as an associative array as well,
1329          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1330          *   Some query patterns will trigger various shorturl path replacements.
1331          * @param $query2 Mixed: An optional secondary query array. This one MUST
1332          *   be an array. If a string is passed it will be interpreted as a deprecated
1333          *   variant argument and urlencoded into a variant= argument.
1334          *   This second query argument will be added to the $query
1335          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1336          *   pair in the first parameter array instead.
1337          *
1338          * @return String the URL
1339          */
1340         public function getLocalURL( $query = '', $query2 = false ) {
1341                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1342
1343                 $query = self::fixUrlQueryArgs( $query, $query2 );
1344
1345                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1346                 if ( $interwiki ) {
1347                         $namespace = $this->getNsText();
1348                         if ( $namespace != '' ) {
1349                                 # Can this actually happen? Interwikis shouldn't be parsed.
1350                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1351                                 $namespace .= ':';
1352                         }
1353                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1354                         $url = wfAppendQuery( $url, $query );
1355                 } else {
1356                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1357                         if ( $query == '' ) {
1358                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1359                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1360                         } else {
1361                                 global $wgVariantArticlePath, $wgActionPaths;
1362                                 $url = false;
1363                                 $matches = array();
1364
1365                                 if ( !empty( $wgActionPaths ) &&
1366                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1367                                 {
1368                                         $action = urldecode( $matches[2] );
1369                                         if ( isset( $wgActionPaths[$action] ) ) {
1370                                                 $query = $matches[1];
1371                                                 if ( isset( $matches[4] ) ) {
1372                                                         $query .= $matches[4];
1373                                                 }
1374                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1375                                                 if ( $query != '' ) {
1376                                                         $url = wfAppendQuery( $url, $query );
1377                                                 }
1378                                         }
1379                                 }
1380
1381                                 if ( $url === false &&
1382                                         $wgVariantArticlePath &&
1383                                         $this->getPageLanguage()->hasVariants() &&
1384                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1385                                 {
1386                                         $variant = urldecode( $matches[1] );
1387                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1388                                                 // Only do the variant replacement if the given variant is a valid
1389                                                 // variant for the page's language.
1390                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1391                                                 $url = str_replace( '$1', $dbkey, $url );
1392                                         }
1393                                 }
1394
1395                                 if ( $url === false ) {
1396                                         if ( $query == '-' ) {
1397                                                 $query = '';
1398                                         }
1399                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1400                                 }
1401                         }
1402
1403                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1404
1405                         // @todo FIXME: This causes breakage in various places when we
1406                         // actually expected a local URL and end up with dupe prefixes.
1407                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1408                                 $url = $wgServer . $url;
1409                         }
1410                 }
1411                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1412                 return $url;
1413         }
1414
1415         /**
1416          * Get a URL that's the simplest URL that will be valid to link, locally,
1417          * to the current Title.  It includes the fragment, but does not include
1418          * the server unless action=render is used (or the link is external).  If
1419          * there's a fragment but the prefixed text is empty, we just return a link
1420          * to the fragment.
1421          *
1422          * The result obviously should not be URL-escaped, but does need to be
1423          * HTML-escaped if it's being output in HTML.
1424          *
1425          * See getLocalURL for the arguments.
1426          *
1427          * @see self::getLocalURL
1428          * @return String the URL
1429          */
1430         public function getLinkURL( $query = '', $query2 = false ) {
1431                 wfProfileIn( __METHOD__ );
1432                 if ( $this->isExternal() ) {
1433                         $ret = $this->getFullURL( $query, $query2 );
1434                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1435                         $ret = $this->getFragmentForURL();
1436                 } else {
1437                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1438                 }
1439                 wfProfileOut( __METHOD__ );
1440                 return $ret;
1441         }
1442
1443         /**
1444          * Get an HTML-escaped version of the URL form, suitable for
1445          * using in a link, without a server name or fragment
1446          *
1447          * See getLocalURL for the arguments.
1448          *
1449          * @see self::getLocalURL
1450          * @return String the URL
1451          */
1452         public function escapeLocalURL( $query = '', $query2 = false ) {
1453                 wfDeprecated( __METHOD__, '1.19' );
1454                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1455         }
1456
1457         /**
1458          * Get an HTML-escaped version of the URL form, suitable for
1459          * using in a link, including the server name and fragment
1460          *
1461          * See getLocalURL for the arguments.
1462          *
1463          * @see self::getLocalURL
1464          * @return String the URL
1465          */
1466         public function escapeFullURL( $query = '', $query2 = false ) {
1467                 wfDeprecated( __METHOD__, '1.19' );
1468                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1469         }
1470
1471         /**
1472          * Get the URL form for an internal link.
1473          * - Used in various Squid-related code, in case we have a different
1474          * internal hostname for the server from the exposed one.
1475          *
1476          * This uses $wgInternalServer to qualify the path, or $wgServer
1477          * if $wgInternalServer is not set. If the server variable used is
1478          * protocol-relative, the URL will be expanded to http://
1479          *
1480          * See getLocalURL for the arguments.
1481          *
1482          * @see self::getLocalURL
1483          * @return String the URL
1484          */
1485         public function getInternalURL( $query = '', $query2 = false ) {
1486                 global $wgInternalServer, $wgServer;
1487                 $query = self::fixUrlQueryArgs( $query, $query2 );
1488                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1489                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1490                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1491                 return $url;
1492         }
1493
1494         /**
1495          * Get the URL for a canonical link, for use in things like IRC and
1496          * e-mail notifications. Uses $wgCanonicalServer and the
1497          * GetCanonicalURL hook.
1498          *
1499          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1500          *
1501          * See getLocalURL for the arguments.
1502          *
1503          * @see self::getLocalURL
1504          * @return string The URL
1505          * @since 1.18
1506          */
1507         public function getCanonicalURL( $query = '', $query2 = false ) {
1508                 $query = self::fixUrlQueryArgs( $query, $query2 );
1509                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1510                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1511                 return $url;
1512         }
1513
1514         /**
1515          * HTML-escaped version of getCanonicalURL()
1516          *
1517          * See getLocalURL for the arguments.
1518          *
1519          * @see self::getLocalURL
1520          * @since 1.18
1521          * @return string
1522          */
1523         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1524                 wfDeprecated( __METHOD__, '1.19' );
1525                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1526         }
1527
1528         /**
1529          * Get the edit URL for this Title
1530          *
1531          * @return String the URL, or a null string if this is an
1532          *  interwiki link
1533          */
1534         public function getEditURL() {
1535                 if ( $this->mInterwiki != '' ) {
1536                         return '';
1537                 }
1538                 $s = $this->getLocalURL( 'action=edit' );
1539
1540                 return $s;
1541         }
1542
1543         /**
1544          * Is $wgUser watching this page?
1545          *
1546          * @return Bool
1547          */
1548         public function userIsWatching() {
1549                 global $wgUser;
1550
1551                 if ( is_null( $this->mWatched ) ) {
1552                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1553                                 $this->mWatched = false;
1554                         } else {
1555                                 $this->mWatched = $wgUser->isWatched( $this );
1556                         }
1557                 }
1558                 return $this->mWatched;
1559         }
1560
1561         /**
1562          * Can $wgUser read this page?
1563          *
1564          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1565          * @return Bool
1566          * @todo fold these checks into userCan()
1567          */
1568         public function userCanRead() {
1569                 wfDeprecated( __METHOD__, '1.19' );
1570                 return $this->userCan( 'read' );
1571         }
1572
1573         /**
1574          * Can $user perform $action on this page?
1575          * This skips potentially expensive cascading permission checks
1576          * as well as avoids expensive error formatting
1577          *
1578          * Suitable for use for nonessential UI controls in common cases, but
1579          * _not_ for functional access control.
1580          *
1581          * May provide false positives, but should never provide a false negative.
1582          *
1583          * @param $action String action that permission needs to be checked for
1584          * @param $user User to check (since 1.19); $wgUser will be used if not
1585          *              provided.
1586          * @return Bool
1587          */
1588         public function quickUserCan( $action, $user = null ) {
1589                 return $this->userCan( $action, $user, false );
1590         }
1591
1592         /**
1593          * Can $user perform $action on this page?
1594          *
1595          * @param $action String action that permission needs to be checked for
1596          * @param $user User to check (since 1.19); $wgUser will be used if not
1597          *   provided.
1598          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1599          *   unnecessary queries.
1600          * @return Bool
1601          */
1602         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1603                 if ( !$user instanceof User ) {
1604                         global $wgUser;
1605                         $user = $wgUser;
1606                 }
1607                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1608         }
1609
1610         /**
1611          * Can $user perform $action on this page?
1612          *
1613          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1614          *
1615          * @param $action String action that permission needs to be checked for
1616          * @param $user User to check
1617          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1618          *   queries by skipping checks for cascading protections and user blocks.
1619          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1620          *   whose corresponding errors may be ignored.
1621          * @return Array of arguments to wfMsg to explain permissions problems.
1622          */
1623         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1624                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1625
1626                 // Remove the errors being ignored.
1627                 foreach ( $errors as $index => $error ) {
1628                         $error_key = is_array( $error ) ? $error[0] : $error;
1629
1630                         if ( in_array( $error_key, $ignoreErrors ) ) {
1631                                 unset( $errors[$index] );
1632                         }
1633                 }
1634
1635                 return $errors;
1636         }
1637
1638         /**
1639          * Permissions checks that fail most often, and which are easiest to test.
1640          *
1641          * @param $action String the action to check
1642          * @param $user User user to check
1643          * @param $errors Array list of current errors
1644          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1645          * @param $short Boolean short circuit on first error
1646          *
1647          * @return Array list of errors
1648          */
1649         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1650                 if ( $action == 'create' ) {
1651                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1652                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1653                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1654                         }
1655                 } elseif ( $action == 'move' ) {
1656                         if ( !$user->isAllowed( 'move-rootuserpages' )
1657                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1658                                 // Show user page-specific message only if the user can move other pages
1659                                 $errors[] = array( 'cant-move-user-page' );
1660                         }
1661
1662                         // Check if user is allowed to move files if it's a file
1663                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1664                                 $errors[] = array( 'movenotallowedfile' );
1665                         }
1666
1667                         if ( !$user->isAllowed( 'move' ) ) {
1668                                 // User can't move anything
1669                                 global $wgGroupPermissions;
1670                                 $userCanMove = false;
1671                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1672                                         $userCanMove = $wgGroupPermissions['user']['move'];
1673                                 }
1674                                 $autoconfirmedCanMove = false;
1675                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1676                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1677                                 }
1678                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1679                                         // custom message if logged-in users without any special rights can move
1680                                         $errors[] = array( 'movenologintext' );
1681                                 } else {
1682                                         $errors[] = array( 'movenotallowed' );
1683                                 }
1684                         }
1685                 } elseif ( $action == 'move-target' ) {
1686                         if ( !$user->isAllowed( 'move' ) ) {
1687                                 // User can't move anything
1688                                 $errors[] = array( 'movenotallowed' );
1689                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1690                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1691                                 // Show user page-specific message only if the user can move other pages
1692                                 $errors[] = array( 'cant-move-to-user-page' );
1693                         }
1694                 } elseif ( !$user->isAllowed( $action ) ) {
1695                         $errors[] = $this->missingPermissionError( $action, $short );
1696                 }
1697
1698                 return $errors;
1699         }
1700
1701         /**
1702          * Add the resulting error code to the errors array
1703          *
1704          * @param $errors Array list of current errors
1705          * @param $result Mixed result of errors
1706          *
1707          * @return Array list of errors
1708          */
1709         private function resultToError( $errors, $result ) {
1710                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1711                         // A single array representing an error
1712                         $errors[] = $result;
1713                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1714                         // A nested array representing multiple errors
1715                         $errors = array_merge( $errors, $result );
1716                 } elseif ( $result !== '' && is_string( $result ) ) {
1717                         // A string representing a message-id
1718                         $errors[] = array( $result );
1719                 } elseif ( $result === false ) {
1720                         // a generic "We don't want them to do that"
1721                         $errors[] = array( 'badaccess-group0' );
1722                 }
1723                 return $errors;
1724         }
1725
1726         /**
1727          * Check various permission hooks
1728          *
1729          * @param $action String the action to check
1730          * @param $user User user to check
1731          * @param $errors Array list of current errors
1732          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1733          * @param $short Boolean short circuit on first error
1734          *
1735          * @return Array list of errors
1736          */
1737         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1738                 // Use getUserPermissionsErrors instead
1739                 $result = '';
1740                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1741                         return $result ? array() : array( array( 'badaccess-group0' ) );
1742                 }
1743                 // Check getUserPermissionsErrors hook
1744                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1745                         $errors = $this->resultToError( $errors, $result );
1746                 }
1747                 // Check getUserPermissionsErrorsExpensive hook
1748                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1749                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1750                         $errors = $this->resultToError( $errors, $result );
1751                 }
1752
1753                 return $errors;
1754         }
1755
1756         /**
1757          * Check permissions on special pages & namespaces
1758          *
1759          * @param $action String the action to check
1760          * @param $user User user to check
1761          * @param $errors Array list of current errors
1762          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1763          * @param $short Boolean short circuit on first error
1764          *
1765          * @return Array list of errors
1766          */
1767         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1768                 # Only 'createaccount' and 'execute' can be performed on
1769                 # special pages, which don't actually exist in the DB.
1770                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1771                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1772                         $errors[] = array( 'ns-specialprotected' );
1773                 }
1774
1775                 # Check $wgNamespaceProtection for restricted namespaces
1776                 if ( $this->isNamespaceProtected( $user ) ) {
1777                         $ns = $this->mNamespace == NS_MAIN ?
1778                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1779                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1780                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1781                 }
1782
1783                 return $errors;
1784         }
1785
1786         /**
1787          * Check CSS/JS sub-page permissions
1788          *
1789          * @param $action String the action to check
1790          * @param $user User user to check
1791          * @param $errors Array list of current errors
1792          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1793          * @param $short Boolean short circuit on first error
1794          *
1795          * @return Array list of errors
1796          */
1797         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1798                 # Protect css/js subpages of user pages
1799                 # XXX: this might be better using restrictions
1800                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1801                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1802                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1803                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1804                                 $errors[] = array( 'customcssprotected' );
1805                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1806                                 $errors[] = array( 'customjsprotected' );
1807                         }
1808                 }
1809
1810                 return $errors;
1811         }
1812
1813         /**
1814          * Check against page_restrictions table requirements on this
1815          * page. The user must possess all required rights for this
1816          * action.
1817          *
1818          * @param $action String the action to check
1819          * @param $user User user to check
1820          * @param $errors Array list of current errors
1821          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1822          * @param $short Boolean short circuit on first error
1823          *
1824          * @return Array list of errors
1825          */
1826         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1827                 foreach ( $this->getRestrictions( $action ) as $right ) {
1828                         // Backwards compatibility, rewrite sysop -> protect
1829                         if ( $right == 'sysop' ) {
1830                                 $right = 'protect';
1831                         }
1832                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1833                                 // Users with 'editprotected' permission can edit protected pages
1834                                 // without cascading option turned on.
1835                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1836                                         || $this->mCascadeRestriction )
1837                                 {
1838                                         $errors[] = array( 'protectedpagetext', $right );
1839                                 }
1840                         }
1841                 }
1842
1843                 return $errors;
1844         }
1845
1846         /**
1847          * Check restrictions on cascading pages.
1848          *
1849          * @param $action String the action to check
1850          * @param $user User to check
1851          * @param $errors Array list of current errors
1852          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1853          * @param $short Boolean short circuit on first error
1854          *
1855          * @return Array list of errors
1856          */
1857         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1858                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1859                         # We /could/ use the protection level on the source page, but it's
1860                         # fairly ugly as we have to establish a precedence hierarchy for pages
1861                         # included by multiple cascade-protected pages. So just restrict
1862                         # it to people with 'protect' permission, as they could remove the
1863                         # protection anyway.
1864                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1865                         # Cascading protection depends on more than this page...
1866                         # Several cascading protected pages may include this page...
1867                         # Check each cascading level
1868                         # This is only for protection restrictions, not for all actions
1869                         if ( isset( $restrictions[$action] ) ) {
1870                                 foreach ( $restrictions[$action] as $right ) {
1871                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1872                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1873                                                 $pages = '';
1874                                                 foreach ( $cascadingSources as $page )
1875                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1876                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1877                                         }
1878                                 }
1879                         }
1880                 }
1881
1882                 return $errors;
1883         }
1884
1885         /**
1886          * Check action permissions not already checked in checkQuickPermissions
1887          *
1888          * @param $action String the action to check
1889          * @param $user User to check
1890          * @param $errors Array list of current errors
1891          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1892          * @param $short Boolean short circuit on first error
1893          *
1894          * @return Array list of errors
1895          */
1896         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1897                 global $wgDeleteRevisionsLimit, $wgLang;
1898
1899                 if ( $action == 'protect' ) {
1900                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1901                                 // If they can't edit, they shouldn't protect.
1902                                 $errors[] = array( 'protect-cantedit' );
1903                         }
1904                 } elseif ( $action == 'create' ) {
1905                         $title_protection = $this->getTitleProtection();
1906                         if( $title_protection ) {
1907                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1908                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1909                                 }
1910                                 if( $title_protection['pt_create_perm'] == '' ||
1911                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1912                                 {
1913                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1914                                 }
1915                         }
1916                 } elseif ( $action == 'move' ) {
1917                         // Check for immobile pages
1918                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1919                                 // Specific message for this case
1920                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1921                         } elseif ( !$this->isMovable() ) {
1922                                 // Less specific message for rarer cases
1923                                 $errors[] = array( 'immobile-source-page' );
1924                         }
1925                 } elseif ( $action == 'move-target' ) {
1926                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1927                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1928                         } elseif ( !$this->isMovable() ) {
1929                                 $errors[] = array( 'immobile-target-page' );
1930                         }
1931                 } elseif ( $action == 'delete' ) {
1932                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1933                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1934                         {
1935                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1936                         }
1937                 }
1938                 return $errors;
1939         }
1940
1941         /**
1942          * Check that the user isn't blocked from editting.
1943          *
1944          * @param $action String the action to check
1945          * @param $user User to check
1946          * @param $errors Array list of current errors
1947          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1948          * @param $short Boolean short circuit on first error
1949          *
1950          * @return Array list of errors
1951          */
1952         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1953                 // Account creation blocks handled at userlogin.
1954                 // Unblocking handled in SpecialUnblock
1955                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1956                         return $errors;
1957                 }
1958
1959                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1960
1961                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1962                         $errors[] = array( 'confirmedittext' );
1963                 }
1964
1965                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1966                         // Don't block the user from editing their own talk page unless they've been
1967                         // explicitly blocked from that too.
1968                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1969                         $block = $user->getBlock();
1970
1971                         // This is from OutputPage::blockedPage
1972                         // Copied at r23888 by werdna
1973
1974                         $id = $user->blockedBy();
1975                         $reason = $user->blockedFor();
1976                         if ( $reason == '' ) {
1977                                 $reason = wfMsg( 'blockednoreason' );
1978                         }
1979                         $ip = $user->getRequest()->getIP();
1980
1981                         if ( is_numeric( $id ) ) {
1982                                 $name = User::whoIs( $id );
1983                         } else {
1984                                 $name = $id;
1985                         }
1986
1987                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1988                         $blockid = $block->getId();
1989                         $blockExpiry = $block->getExpiry();
1990                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
1991                         if ( $blockExpiry == 'infinity' ) {
1992                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1993                         } else {
1994                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1995                         }
1996
1997                         $intended = strval( $block->getTarget() );
1998
1999                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
2000                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
2001                 }
2002
2003                 return $errors;
2004         }
2005
2006         /**
2007          * Check that the user is allowed to read this page.
2008          *
2009          * @param $action String the action to check
2010          * @param $user User to check
2011          * @param $errors Array list of current errors
2012          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2013          * @param $short Boolean short circuit on first error
2014          *
2015          * @return Array list of errors
2016          */
2017         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2018                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
2019                 static $useShortcut = null;
2020
2021                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2022                 if ( is_null( $useShortcut ) ) {
2023                         $useShortcut = true;
2024                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
2025                                 # Not a public wiki, so no shortcut
2026                                 $useShortcut = false;
2027                         } elseif ( !empty( $wgRevokePermissions ) ) {
2028                                 /**
2029                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2030                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2031                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2032                                  * reading is allowed.
2033                                  */
2034                                 foreach ( $wgRevokePermissions as $perms ) {
2035                                         if ( !empty( $perms['read'] ) ) {
2036                                                 # We might be removing the read right from the user, so no shortcut
2037                                                 $useShortcut = false;
2038                                                 break;
2039                                         }
2040                                 }
2041                         }
2042                 }
2043
2044                 $whitelisted = false;
2045                 if ( $useShortcut ) {
2046                         # Shortcut for public wikis, allows skipping quite a bit of code
2047                         $whitelisted = true;
2048                 } elseif ( $user->isAllowed( 'read' ) ) {
2049                         # If the user is allowed to read pages, he is allowed to read all pages
2050                         $whitelisted = true;
2051                 } elseif ( $this->isSpecial( 'Userlogin' )
2052                         || $this->isSpecial( 'ChangePassword' )
2053                         || $this->isSpecial( 'PasswordReset' )
2054                 ) {
2055                         # Always grant access to the login page.
2056                         # Even anons need to be able to log in.
2057                         $whitelisted = true;
2058                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2059                         # Time to check the whitelist
2060                         # Only do these checks is there's something to check against
2061                         $name = $this->getPrefixedText();
2062                         $dbName = $this->getPrefixedDBKey();
2063
2064                         // Check for explicit whitelisting with and without underscores
2065                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2066                                 $whitelisted = true;
2067                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2068                                 # Old settings might have the title prefixed with
2069                                 # a colon for main-namespace pages
2070                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2071                                         $whitelisted = true;
2072                                 }
2073                         } elseif ( $this->isSpecialPage() ) {
2074                                 # If it's a special page, ditch the subpage bit and check again
2075                                 $name = $this->getDBkey();
2076                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2077                                 if ( $name !== false ) {
2078                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2079                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2080                                                 $whitelisted = true;
2081                                         }
2082                                 }
2083                         }
2084                 }
2085
2086                 if ( !$whitelisted ) {
2087                         # If the title is not whitelisted, give extensions a chance to do so...
2088                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2089                         if ( !$whitelisted ) {
2090                                 $errors[] = $this->missingPermissionError( $action, $short );
2091                         }
2092                 }
2093
2094                 return $errors;
2095         }
2096
2097         /**
2098          * Get a description array when the user doesn't have the right to perform
2099          * $action (i.e. when User::isAllowed() returns false)
2100          *
2101          * @param $action String the action to check
2102          * @param $short Boolean short circuit on first error
2103          * @return Array list of errors
2104          */
2105         private function missingPermissionError( $action, $short ) {
2106                 // We avoid expensive display logic for quickUserCan's and such
2107                 if ( $short ) {
2108                         return array( 'badaccess-group0' );
2109                 }
2110
2111                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2112                         User::getGroupsWithPermission( $action ) );
2113
2114                 if ( count( $groups ) ) {
2115                         global $wgLang;
2116                         return array(
2117                                 'badaccess-groups',
2118                                 $wgLang->commaList( $groups ),
2119                                 count( $groups )
2120                         );
2121                 } else {
2122                         return array( 'badaccess-group0' );
2123                 }
2124         }
2125
2126         /**
2127          * Can $user perform $action on this page? This is an internal function,
2128          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2129          * checks on wfReadOnly() and blocks)
2130          *
2131          * @param $action String action that permission needs to be checked for
2132          * @param $user User to check
2133          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2134          * @param $short Bool Set this to true to stop after the first permission error.
2135          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2136          */
2137         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2138                 wfProfileIn( __METHOD__ );
2139
2140                 # Read has special handling
2141                 if ( $action == 'read' ) {
2142                         $checks = array(
2143                                 'checkPermissionHooks',
2144                                 'checkReadPermissions',
2145                         );
2146                 } else {
2147                         $checks = array(
2148                                 'checkQuickPermissions',
2149                                 'checkPermissionHooks',
2150                                 'checkSpecialsAndNSPermissions',
2151                                 'checkCSSandJSPermissions',
2152                                 'checkPageRestrictions',
2153                                 'checkCascadingSourcesRestrictions',
2154                                 'checkActionPermissions',
2155                                 'checkUserBlock'
2156                         );
2157                 }
2158
2159                 $errors = array();
2160                 while( count( $checks ) > 0 &&
2161                                 !( $short && count( $errors ) > 0 ) ) {
2162                         $method = array_shift( $checks );
2163                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2164                 }
2165
2166                 wfProfileOut( __METHOD__ );
2167                 return $errors;
2168         }
2169
2170         /**
2171          * Protect css subpages of user pages: can $wgUser edit
2172          * this page?
2173          *
2174          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2175          * @return Bool
2176          */
2177         public function userCanEditCssSubpage() {
2178                 global $wgUser;
2179                 wfDeprecated( __METHOD__, '1.19' );
2180                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2181                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2182         }
2183
2184         /**
2185          * Protect js subpages of user pages: can $wgUser edit
2186          * this page?
2187          *
2188          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2189          * @return Bool
2190          */
2191         public function userCanEditJsSubpage() {
2192                 global $wgUser;
2193                 wfDeprecated( __METHOD__, '1.19' );
2194                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2195                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2196         }
2197
2198         /**
2199          * Get a filtered list of all restriction types supported by this wiki.
2200          * @param bool $exists True to get all restriction types that apply to
2201          * titles that do exist, False for all restriction types that apply to
2202          * titles that do not exist
2203          * @return array
2204          */
2205         public static function getFilteredRestrictionTypes( $exists = true ) {
2206                 global $wgRestrictionTypes;
2207                 $types = $wgRestrictionTypes;
2208                 if ( $exists ) {
2209                         # Remove the create restriction for existing titles
2210                         $types = array_diff( $types, array( 'create' ) );
2211                 } else {
2212                         # Only the create and upload restrictions apply to non-existing titles
2213                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2214                 }
2215                 return $types;
2216         }
2217
2218         /**
2219          * Returns restriction types for the current Title
2220          *
2221          * @return array applicable restriction types
2222          */
2223         public function getRestrictionTypes() {
2224                 if ( $this->isSpecialPage() ) {
2225                         return array();
2226                 }
2227
2228                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2229
2230                 if ( $this->getNamespace() != NS_FILE ) {
2231                         # Remove the upload restriction for non-file titles
2232                         $types = array_diff( $types, array( 'upload' ) );
2233                 }
2234
2235                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2236
2237                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2238                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2239
2240                 return $types;
2241         }
2242
2243         /**
2244          * Is this title subject to title protection?
2245          * Title protection is the one applied against creation of such title.
2246          *
2247          * @return Mixed An associative array representing any existent title
2248          *   protection, or false if there's none.
2249          */
2250         private function getTitleProtection() {
2251                 // Can't protect pages in special namespaces
2252                 if ( $this->getNamespace() < 0 ) {
2253                         return false;
2254                 }
2255
2256                 // Can't protect pages that exist.
2257                 if ( $this->exists() ) {
2258                         return false;
2259                 }
2260
2261                 if ( !isset( $this->mTitleProtection ) ) {
2262                         $dbr = wfGetDB( DB_SLAVE );
2263                         $res = $dbr->select( 'protected_titles', '*',
2264                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2265                                 __METHOD__ );
2266
2267                         // fetchRow returns false if there are no rows.
2268                         $this->mTitleProtection = $dbr->fetchRow( $res );
2269                 }
2270                 return $this->mTitleProtection;
2271         }
2272
2273         /**
2274          * Update the title protection status
2275          *
2276          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2277          * @param $create_perm String Permission required for creation
2278          * @param $reason String Reason for protection
2279          * @param $expiry String Expiry timestamp
2280          * @return boolean true
2281          */
2282         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2283                 wfDeprecated( __METHOD__, '1.19' );
2284
2285                 global $wgUser;
2286
2287                 $limit = array( 'create' => $create_perm );
2288                 $expiry = array( 'create' => $expiry );
2289
2290                 $page = WikiPage::factory( $this );
2291                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2292
2293                 return $status->isOK();
2294         }
2295
2296         /**
2297          * Remove any title protection due to page existing
2298          */
2299         public function deleteTitleProtection() {
2300                 $dbw = wfGetDB( DB_MASTER );
2301
2302                 $dbw->delete(
2303                         'protected_titles',
2304                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2305                         __METHOD__
2306                 );
2307                 $this->mTitleProtection = false;
2308         }
2309
2310         /**
2311          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2312          *
2313          * @param $action String Action to check (default: edit)
2314          * @return Bool
2315          */
2316         public function isSemiProtected( $action = 'edit' ) {
2317                 if ( $this->exists() ) {
2318                         $restrictions = $this->getRestrictions( $action );
2319                         if ( count( $restrictions ) > 0 ) {
2320                                 foreach ( $restrictions as $restriction ) {
2321                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2322                                                 return false;
2323                                         }
2324                                 }
2325                         } else {
2326                                 # Not protected
2327                                 return false;
2328                         }
2329                         return true;
2330                 } else {
2331                         # If it doesn't exist, it can't be protected
2332                         return false;
2333                 }
2334         }
2335
2336         /**
2337          * Does the title correspond to a protected article?
2338          *
2339          * @param $action String the action the page is protected from,
2340          * by default checks all actions.
2341          * @return Bool
2342          */
2343         public function isProtected( $action = '' ) {
2344                 global $wgRestrictionLevels;
2345
2346                 $restrictionTypes = $this->getRestrictionTypes();
2347
2348                 # Special pages have inherent protection
2349                 if( $this->isSpecialPage() ) {
2350                         return true;
2351                 }
2352
2353                 # Check regular protection levels
2354                 foreach ( $restrictionTypes as $type ) {
2355                         if ( $action == $type || $action == '' ) {
2356                                 $r = $this->getRestrictions( $type );
2357                                 foreach ( $wgRestrictionLevels as $level ) {
2358                                         if ( in_array( $level, $r ) && $level != '' ) {
2359                                                 return true;
2360                                         }
2361                                 }
2362                         }
2363                 }
2364
2365                 return false;
2366         }
2367
2368         /**
2369          * Determines if $user is unable to edit this page because it has been protected
2370          * by $wgNamespaceProtection.
2371          *
2372          * @param $user User object to check permissions
2373          * @return Bool
2374          */
2375         public function isNamespaceProtected( User $user ) {
2376                 global $wgNamespaceProtection;
2377
2378                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2379                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2380                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2381                                         return true;
2382                                 }
2383                         }
2384                 }
2385                 return false;
2386         }
2387
2388         /**
2389          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2390          *
2391          * @return Bool If the page is subject to cascading restrictions.
2392          */
2393         public function isCascadeProtected() {
2394                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2395                 return ( $sources > 0 );
2396         }
2397
2398         /**
2399          * Cascading protection: Get the source of any cascading restrictions on this page.
2400          *
2401          * @param $getPages Bool Whether or not to retrieve the actual pages
2402          *        that the restrictions have come from.
2403          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2404          *     have come, false for none, or true if such restrictions exist, but $getPages
2405          *     was not set.  The restriction array is an array of each type, each of which
2406          *     contains a array of unique groups.
2407          */
2408         public function getCascadeProtectionSources( $getPages = true ) {
2409                 global $wgContLang;
2410                 $pagerestrictions = array();
2411
2412                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2413                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2414                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2415                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2416                 }
2417
2418                 wfProfileIn( __METHOD__ );
2419
2420                 $dbr = wfGetDB( DB_SLAVE );
2421
2422                 if ( $this->getNamespace() == NS_FILE ) {
2423                         $tables = array( 'imagelinks', 'page_restrictions' );
2424                         $where_clauses = array(
2425                                 'il_to' => $this->getDBkey(),
2426                                 'il_from=pr_page',
2427                                 'pr_cascade' => 1
2428                         );
2429                 } else {
2430                         $tables = array( 'templatelinks', 'page_restrictions' );
2431                         $where_clauses = array(
2432                                 'tl_namespace' => $this->getNamespace(),
2433                                 'tl_title' => $this->getDBkey(),
2434                                 'tl_from=pr_page',
2435                                 'pr_cascade' => 1
2436                         );
2437                 }
2438
2439                 if ( $getPages ) {
2440                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2441                                                    'pr_expiry', 'pr_type', 'pr_level' );
2442                         $where_clauses[] = 'page_id=pr_page';
2443                         $tables[] = 'page';
2444                 } else {
2445                         $cols = array( 'pr_expiry' );
2446                 }
2447
2448                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2449
2450                 $sources = $getPages ? array() : false;
2451                 $now = wfTimestampNow();
2452                 $purgeExpired = false;
2453
2454                 foreach ( $res as $row ) {
2455                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2456                         if ( $expiry > $now ) {
2457                                 if ( $getPages ) {
2458                                         $page_id = $row->pr_page;
2459                                         $page_ns = $row->page_namespace;
2460                                         $page_title = $row->page_title;
2461                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2462                                         # Add groups needed for each restriction type if its not already there
2463                                         # Make sure this restriction type still exists
2464
2465                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2466                                                 $pagerestrictions[$row->pr_type] = array();
2467                                         }
2468
2469                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2470                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2471                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2472                                         }
2473                                 } else {
2474                                         $sources = true;
2475                                 }
2476                         } else {
2477                                 // Trigger lazy purge of expired restrictions from the db
2478                                 $purgeExpired = true;
2479                         }
2480                 }
2481                 if ( $purgeExpired ) {
2482                         Title::purgeExpiredRestrictions();
2483                 }
2484
2485                 if ( $getPages ) {
2486                         $this->mCascadeSources = $sources;
2487                         $this->mCascadingRestrictions = $pagerestrictions;
2488                 } else {
2489                         $this->mHasCascadingRestrictions = $sources;
2490                 }
2491
2492                 wfProfileOut( __METHOD__ );
2493                 return array( $sources, $pagerestrictions );
2494         }
2495
2496         /**
2497          * Accessor/initialisation for mRestrictions
2498          *
2499          * @param $action String action that permission needs to be checked for
2500          * @return Array of Strings the array of groups allowed to edit this article
2501          */
2502         public function getRestrictions( $action ) {
2503                 if ( !$this->mRestrictionsLoaded ) {
2504                         $this->loadRestrictions();
2505                 }
2506                 return isset( $this->mRestrictions[$action] )
2507                                 ? $this->mRestrictions[$action]
2508                                 : array();
2509         }
2510
2511         /**
2512          * Get the expiry time for the restriction against a given action
2513          *
2514          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2515          *      or not protected at all, or false if the action is not recognised.
2516          */
2517         public function getRestrictionExpiry( $action ) {
2518                 if ( !$this->mRestrictionsLoaded ) {
2519                         $this->loadRestrictions();
2520                 }
2521                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2522         }
2523
2524         /**
2525          * Returns cascading restrictions for the current article
2526          *
2527          * @return Boolean
2528          */
2529         function areRestrictionsCascading() {
2530                 if ( !$this->mRestrictionsLoaded ) {
2531                         $this->loadRestrictions();
2532                 }
2533
2534                 return $this->mCascadeRestriction;
2535         }
2536
2537         /**
2538          * Loads a string into mRestrictions array
2539          *
2540          * @param $res Resource restrictions as an SQL result.
2541          * @param $oldFashionedRestrictions String comma-separated list of page
2542          *        restrictions from page table (pre 1.10)
2543          */
2544         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2545                 $rows = array();
2546
2547                 foreach ( $res as $row ) {
2548                         $rows[] = $row;
2549                 }
2550
2551                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2552         }
2553
2554         /**
2555          * Compiles list of active page restrictions from both page table (pre 1.10)
2556          * and page_restrictions table for this existing page.
2557          * Public for usage by LiquidThreads.
2558          *
2559          * @param $rows array of db result objects
2560          * @param $oldFashionedRestrictions string comma-separated list of page
2561          *        restrictions from page table (pre 1.10)
2562          */
2563         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2564                 global $wgContLang;
2565                 $dbr = wfGetDB( DB_SLAVE );
2566
2567                 $restrictionTypes = $this->getRestrictionTypes();
2568
2569                 foreach ( $restrictionTypes as $type ) {
2570                         $this->mRestrictions[$type] = array();
2571                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2572                 }
2573
2574                 $this->mCascadeRestriction = false;
2575
2576                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2577
2578                 if ( $oldFashionedRestrictions === null ) {
2579                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2580                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2581                 }
2582
2583                 if ( $oldFashionedRestrictions != '' ) {
2584
2585                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2586                                 $temp = explode( '=', trim( $restrict ) );
2587                                 if ( count( $temp ) == 1 ) {
2588                                         // old old format should be treated as edit/move restriction
2589                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2590                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2591                                 } else {
2592                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2593                                 }
2594                         }
2595
2596                         $this->mOldRestrictions = true;
2597
2598                 }
2599
2600                 if ( count( $rows ) ) {
2601                         # Current system - load second to make them override.
2602                         $now = wfTimestampNow();
2603                         $purgeExpired = false;
2604
2605                         # Cycle through all the restrictions.
2606                         foreach ( $rows as $row ) {
2607
2608                                 // Don't take care of restrictions types that aren't allowed
2609                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2610                                         continue;
2611
2612                                 // This code should be refactored, now that it's being used more generally,
2613                                 // But I don't really see any harm in leaving it in Block for now -werdna
2614                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2615
2616                                 // Only apply the restrictions if they haven't expired!
2617                                 if ( !$expiry || $expiry > $now ) {
2618                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2619                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2620
2621                                         $this->mCascadeRestriction |= $row->pr_cascade;
2622                                 } else {
2623                                         // Trigger a lazy purge of expired restrictions
2624                                         $purgeExpired = true;
2625                                 }
2626                         }
2627
2628                         if ( $purgeExpired ) {
2629                                 Title::purgeExpiredRestrictions();
2630                         }
2631                 }
2632
2633                 $this->mRestrictionsLoaded = true;
2634         }
2635
2636         /**
2637          * Load restrictions from the page_restrictions table
2638          *
2639          * @param $oldFashionedRestrictions String comma-separated list of page
2640          *        restrictions from page table (pre 1.10)
2641          */
2642         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2643                 global $wgContLang;
2644                 if ( !$this->mRestrictionsLoaded ) {
2645                         if ( $this->exists() ) {
2646                                 $dbr = wfGetDB( DB_SLAVE );
2647
2648                                 $res = $dbr->select(
2649                                         'page_restrictions',
2650                                         '*',
2651                                         array( 'pr_page' => $this->getArticleID() ),
2652                                         __METHOD__
2653                                 );
2654
2655                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2656                         } else {
2657                                 $title_protection = $this->getTitleProtection();
2658
2659                                 if ( $title_protection ) {
2660                                         $now = wfTimestampNow();
2661                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2662
2663                                         if ( !$expiry || $expiry > $now ) {
2664                                                 // Apply the restrictions
2665                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2666                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2667                                         } else { // Get rid of the old restrictions
2668                                                 Title::purgeExpiredRestrictions();
2669                                                 $this->mTitleProtection = false;
2670                                         }
2671                                 } else {
2672                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2673                                 }
2674                                 $this->mRestrictionsLoaded = true;
2675                         }
2676                 }
2677         }
2678
2679         /**
2680          * Flush the protection cache in this object and force reload from the database.
2681          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2682          */
2683         public function flushRestrictions() {
2684                 $this->mRestrictionsLoaded = false;
2685                 $this->mTitleProtection = null;
2686         }
2687
2688         /**
2689          * Purge expired restrictions from the page_restrictions table
2690          */
2691         static function purgeExpiredRestrictions() {
2692                 $dbw = wfGetDB( DB_MASTER );
2693                 $dbw->delete(
2694                         'page_restrictions',
2695                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2696                         __METHOD__
2697                 );
2698
2699                 $dbw->delete(
2700                         'protected_titles',
2701                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2702                         __METHOD__
2703                 );
2704         }
2705
2706         /**
2707          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2708          *
2709          * @return Bool
2710          */
2711         public function hasSubpages() {
2712                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2713                         # Duh
2714                         return false;
2715                 }
2716
2717                 # We dynamically add a member variable for the purpose of this method
2718                 # alone to cache the result.  There's no point in having it hanging
2719                 # around uninitialized in every Title object; therefore we only add it
2720                 # if needed and don't declare it statically.
2721                 if ( isset( $this->mHasSubpages ) ) {
2722                         return $this->mHasSubpages;
2723                 }
2724
2725                 $subpages = $this->getSubpages( 1 );
2726                 if ( $subpages instanceof TitleArray ) {
2727                         return $this->mHasSubpages = (bool)$subpages->count();
2728                 }
2729                 return $this->mHasSubpages = false;
2730         }
2731
2732         /**
2733          * Get all subpages of this page.
2734          *
2735          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2736          * @return mixed TitleArray, or empty array if this page's namespace
2737          *  doesn't allow subpages
2738          */
2739         public function getSubpages( $limit = -1 ) {
2740                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2741                         return array();
2742                 }
2743
2744                 $dbr = wfGetDB( DB_SLAVE );
2745                 $conds['page_namespace'] = $this->getNamespace();
2746                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2747                 $options = array();
2748                 if ( $limit > -1 ) {
2749                         $options['LIMIT'] = $limit;
2750                 }
2751                 return $this->mSubpages = TitleArray::newFromResult(
2752                         $dbr->select( 'page',
2753                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2754                                 $conds,
2755                                 __METHOD__,
2756                                 $options
2757                         )
2758                 );
2759         }
2760
2761         /**
2762          * Is there a version of this page in the deletion archive?
2763          *
2764          * @return Int the number of archived revisions
2765          */
2766         public function isDeleted() {
2767                 if ( $this->getNamespace() < 0 ) {
2768                         $n = 0;
2769                 } else {
2770                         $dbr = wfGetDB( DB_SLAVE );
2771
2772                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2773                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2774                                 __METHOD__
2775                         );
2776                         if ( $this->getNamespace() == NS_FILE ) {
2777                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2778                                         array( 'fa_name' => $this->getDBkey() ),
2779                                         __METHOD__
2780                                 );
2781                         }
2782                 }
2783                 return (int)$n;
2784         }
2785
2786         /**
2787          * Is there a version of this page in the deletion archive?
2788          *
2789          * @return Boolean
2790          */
2791         public function isDeletedQuick() {
2792                 if ( $this->getNamespace() < 0 ) {
2793                         return false;
2794                 }
2795                 $dbr = wfGetDB( DB_SLAVE );
2796                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2797                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2798                         __METHOD__
2799                 );
2800                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2801                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2802                                 array( 'fa_name' => $this->getDBkey() ),
2803                                 __METHOD__
2804                         );
2805                 }
2806                 return $deleted;
2807         }
2808
2809         /**
2810          * Get the article ID for this Title from the link cache,
2811          * adding it if necessary
2812          *
2813          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2814          *  for update
2815          * @return Int the ID
2816          */
2817         public function getArticleID( $flags = 0 ) {
2818                 if ( $this->getNamespace() < 0 ) {
2819                         return $this->mArticleID = 0;
2820                 }
2821                 $linkCache = LinkCache::singleton();
2822                 if ( $flags & self::GAID_FOR_UPDATE ) {
2823                         $oldUpdate = $linkCache->forUpdate( true );
2824                         $linkCache->clearLink( $this );
2825                         $this->mArticleID = $linkCache->addLinkObj( $this );
2826                         $linkCache->forUpdate( $oldUpdate );
2827                 } else {
2828                         if ( -1 == $this->mArticleID ) {
2829                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2830                         }
2831                 }
2832                 return $this->mArticleID;
2833         }
2834
2835         /**
2836          * Is this an article that is a redirect page?
2837          * Uses link cache, adding it if necessary
2838          *
2839          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2840          * @return Bool
2841          */
2842         public function isRedirect( $flags = 0 ) {
2843                 if ( !is_null( $this->mRedirect ) ) {
2844                         return $this->mRedirect;
2845                 }
2846                 # Calling getArticleID() loads the field from cache as needed
2847                 if ( !$this->getArticleID( $flags ) ) {
2848                         return $this->mRedirect = false;
2849                 }
2850                 $linkCache = LinkCache::singleton();
2851                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2852
2853                 return $this->mRedirect;
2854         }
2855
2856         /**
2857          * What is the length of this page?
2858          * Uses link cache, adding it if necessary
2859          *
2860          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2861          * @return Int
2862          */
2863         public function getLength( $flags = 0 ) {
2864                 if ( $this->mLength != -1 ) {
2865                         return $this->mLength;
2866                 }
2867                 # Calling getArticleID() loads the field from cache as needed
2868                 if ( !$this->getArticleID( $flags ) ) {
2869                         return $this->mLength = 0;
2870                 }
2871                 $linkCache = LinkCache::singleton();
2872                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2873
2874                 return $this->mLength;
2875         }
2876
2877         /**
2878          * What is the page_latest field for this page?
2879          *
2880          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2881          * @return Int or 0 if the page doesn't exist
2882          */
2883         public function getLatestRevID( $flags = 0 ) {
2884                 if ( $this->mLatestID !== false ) {
2885                         return intval( $this->mLatestID );
2886                 }
2887                 # Calling getArticleID() loads the field from cache as needed
2888                 if ( !$this->getArticleID( $flags ) ) {
2889                         return $this->mLatestID = 0;
2890                 }
2891                 $linkCache = LinkCache::singleton();
2892                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2893
2894                 return $this->mLatestID;
2895         }
2896
2897         /**
2898          * This clears some fields in this object, and clears any associated
2899          * keys in the "bad links" section of the link cache.
2900          *
2901          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2902          * loading of the new page_id. It's also called from
2903          * WikiPage::doDeleteArticle()
2904          *
2905          * @param $newid Int the new Article ID
2906          */
2907         public function resetArticleID( $newid ) {
2908                 $linkCache = LinkCache::singleton();
2909                 $linkCache->clearLink( $this );
2910
2911                 if ( $newid === false ) {
2912                         $this->mArticleID = -1;
2913                 } else {
2914                         $this->mArticleID = intval( $newid );
2915                 }
2916                 $this->mRestrictionsLoaded = false;
2917                 $this->mRestrictions = array();
2918                 $this->mRedirect = null;
2919                 $this->mLength = -1;
2920                 $this->mLatestID = false;
2921                 $this->mEstimateRevisions = null;
2922         }
2923
2924         /**
2925          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2926          *
2927          * @param $text String containing title to capitalize
2928          * @param $ns int namespace index, defaults to NS_MAIN
2929          * @return String containing capitalized title
2930          */
2931         public static function capitalize( $text, $ns = NS_MAIN ) {
2932                 global $wgContLang;
2933
2934                 if ( MWNamespace::isCapitalized( $ns ) ) {
2935                         return $wgContLang->ucfirst( $text );
2936                 } else {
2937                         return $text;
2938                 }
2939         }
2940
2941         /**
2942          * Secure and split - main initialisation function for this object
2943          *
2944          * Assumes that mDbkeyform has been set, and is urldecoded
2945          * and uses underscores, but not otherwise munged.  This function
2946          * removes illegal characters, splits off the interwiki and
2947          * namespace prefixes, sets the other forms, and canonicalizes
2948          * everything.
2949          *
2950          * @return Bool true on success
2951          */
2952         private function secureAndSplit() {
2953                 global $wgContLang, $wgLocalInterwiki;
2954
2955                 # Initialisation
2956                 $this->mInterwiki = $this->mFragment = '';
2957                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2958
2959                 $dbkey = $this->mDbkeyform;
2960
2961                 # Strip Unicode bidi override characters.
2962                 # Sometimes they slip into cut-n-pasted page titles, where the
2963                 # override chars get included in list displays.
2964                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2965
2966                 # Clean up whitespace
2967                 # Note: use of the /u option on preg_replace here will cause
2968                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2969                 # conveniently disabling them.
2970                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2971                 $dbkey = trim( $dbkey, '_' );
2972
2973                 if ( $dbkey == '' ) {
2974                         return false;
2975                 }
2976
2977                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2978                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2979                         return false;
2980                 }
2981
2982                 $this->mDbkeyform = $dbkey;
2983
2984                 # Initial colon indicates main namespace rather than specified default
2985                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2986                 if ( ':' == $dbkey[0] ) {
2987                         $this->mNamespace = NS_MAIN;
2988                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2989                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2990                 }
2991
2992                 # Namespace or interwiki prefix
2993                 $firstPass = true;
2994                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2995                 do {
2996                         $m = array();
2997                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2998                                 $p = $m[1];
2999                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3000                                         # Ordinary namespace
3001                                         $dbkey = $m[2];
3002                                         $this->mNamespace = $ns;
3003                                         # For Talk:X pages, check if X has a "namespace" prefix
3004                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3005                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3006                                                         # Disallow Talk:File:x type titles...
3007                                                         return false;
3008                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3009                                                         # Disallow Talk:Interwiki:x type titles...
3010                                                         return false;
3011                                                 }
3012                                         }
3013                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3014                                         if ( !$firstPass ) {
3015                                                 # Can't make a local interwiki link to an interwiki link.
3016                                                 # That's just crazy!
3017                                                 return false;
3018                                         }
3019
3020                                         # Interwiki link
3021                                         $dbkey = $m[2];
3022                                         $this->mInterwiki = $wgContLang->lc( $p );
3023
3024                                         # Redundant interwiki prefix to the local wiki
3025                                         if ( $wgLocalInterwiki !== false
3026                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3027                                         {
3028                                                 if ( $dbkey == '' ) {
3029                                                         # Can't have an empty self-link
3030                                                         return false;
3031                                                 }
3032                                                 $this->mInterwiki = '';
3033                                                 $firstPass = false;
3034                                                 # Do another namespace split...
3035                                                 continue;
3036                                         }
3037
3038                                         # If there's an initial colon after the interwiki, that also
3039                                         # resets the default namespace
3040                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3041                                                 $this->mNamespace = NS_MAIN;
3042                                                 $dbkey = substr( $dbkey, 1 );
3043                                         }
3044                                 }
3045                                 # If there's no recognized interwiki or namespace,
3046                                 # then let the colon expression be part of the title.
3047                         }
3048                         break;
3049                 } while ( true );
3050
3051                 # We already know that some pages won't be in the database!
3052                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3053                         $this->mArticleID = 0;
3054                 }
3055                 $fragment = strstr( $dbkey, '#' );
3056                 if ( false !== $fragment ) {
3057                         $this->setFragment( $fragment );
3058                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3059                         # remove whitespace again: prevents "Foo_bar_#"
3060                         # becoming "Foo_bar_"
3061                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3062                 }
3063
3064                 # Reject illegal characters.
3065                 $rxTc = self::getTitleInvalidRegex();
3066                 if ( preg_match( $rxTc, $dbkey ) ) {
3067                         return false;
3068                 }
3069
3070                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3071                 # reachable due to the way web browsers deal with 'relative' URLs.
3072                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3073                 if ( strpos( $dbkey, '.' ) !== false &&
3074                          ( $dbkey === '.' || $dbkey === '..' ||
3075                            strpos( $dbkey, './' ) === 0  ||
3076                            strpos( $dbkey, '../' ) === 0 ||
3077                            strpos( $dbkey, '/./' ) !== false ||
3078                            strpos( $dbkey, '/../' ) !== false  ||
3079                            substr( $dbkey, -2 ) == '/.' ||
3080                            substr( $dbkey, -3 ) == '/..' ) )
3081                 {
3082                         return false;
3083                 }
3084
3085                 # Magic tilde sequences? Nu-uh!
3086                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3087                         return false;
3088                 }
3089
3090                 # Limit the size of titles to 255 bytes. This is typically the size of the
3091                 # underlying database field. We make an exception for special pages, which
3092                 # don't need to be stored in the database, and may edge over 255 bytes due
3093                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3094                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3095                   strlen( $dbkey ) > 512 )
3096                 {
3097                         return false;
3098                 }
3099
3100                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3101                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3102                 # other site might be case-sensitive.
3103                 $this->mUserCaseDBKey = $dbkey;
3104                 if ( $this->mInterwiki == '' ) {
3105                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3106                 }
3107
3108                 # Can't make a link to a namespace alone... "empty" local links can only be
3109                 # self-links with a fragment identifier.
3110                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3111                         return false;
3112                 }
3113
3114                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3115                 // IP names are not allowed for accounts, and can only be referring to
3116                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3117                 // there are numerous ways to present the same IP. Having sp:contribs scan
3118                 // them all is silly and having some show the edits and others not is
3119                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3120                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3121                         ? IP::sanitizeIP( $dbkey )
3122                         : $dbkey;
3123
3124                 // Any remaining initial :s are illegal.
3125                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3126                         return false;
3127                 }
3128
3129                 # Fill fields
3130                 $this->mDbkeyform = $dbkey;
3131                 $this->mUrlform = wfUrlencode( $dbkey );
3132
3133                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3134
3135                 return true;
3136         }
3137
3138         /**
3139          * Get an array of Title objects linking to this Title
3140          * Also stores the IDs in the link cache.
3141          *
3142          * WARNING: do not use this function on arbitrary user-supplied titles!
3143          * On heavily-used templates it will max out the memory.
3144          *
3145          * @param $options Array: may be FOR UPDATE
3146          * @param $table String: table name
3147          * @param $prefix String: fields prefix
3148          * @return Array of Title objects linking here
3149          */
3150         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3151                 if ( count( $options ) > 0 ) {
3152                         $db = wfGetDB( DB_MASTER );
3153                 } else {
3154                         $db = wfGetDB( DB_SLAVE );
3155                 }
3156
3157                 $res = $db->select(
3158                         array( 'page', $table ),
3159                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3160                         array(
3161                                 "{$prefix}_from=page_id",
3162                                 "{$prefix}_namespace" => $this->getNamespace(),
3163                                 "{$prefix}_title"     => $this->getDBkey() ),
3164                         __METHOD__,
3165                         $options
3166                 );
3167
3168                 $retVal = array();
3169                 if ( $res->numRows() ) {
3170                         $linkCache = LinkCache::singleton();
3171                         foreach ( $res as $row ) {
3172                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3173                                 if ( $titleObj ) {
3174                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3175                                         $retVal[] = $titleObj;
3176                                 }
3177                         }
3178                 }
3179                 return $retVal;
3180         }
3181
3182         /**
3183          * Get an array of Title objects using this Title as a template
3184          * Also stores the IDs in the link cache.
3185          *
3186          * WARNING: do not use this function on arbitrary user-supplied titles!
3187          * On heavily-used templates it will max out the memory.
3188          *
3189          * @param $options Array: may be FOR UPDATE
3190          * @return Array of Title the Title objects linking here
3191          */
3192         public function getTemplateLinksTo( $options = array() ) {
3193                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3194         }
3195
3196         /**
3197          * Get an array of Title objects linked from this Title
3198          * Also stores the IDs in the link cache.
3199          *
3200          * WARNING: do not use this function on arbitrary user-supplied titles!
3201          * On heavily-used templates it will max out the memory.
3202          *
3203          * @param $options Array: may be FOR UPDATE
3204          * @param $table String: table name
3205          * @param $prefix String: fields prefix
3206          * @return Array of Title objects linking here
3207          */
3208         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3209                 $id = $this->getArticleID();
3210
3211                 # If the page doesn't exist; there can't be any link from this page
3212                 if ( !$id ) {
3213                         return array();
3214                 }
3215
3216                 if ( count( $options ) > 0 ) {
3217                         $db = wfGetDB( DB_MASTER );
3218                 } else {
3219                         $db = wfGetDB( DB_SLAVE );
3220                 }
3221
3222                 $namespaceFiled = "{$prefix}_namespace";
3223                 $titleField = "{$prefix}_title";
3224
3225                 $res = $db->select(
3226                         array( $table, 'page' ),
3227                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3228                         array( "{$prefix}_from" => $id ),
3229                         __METHOD__,
3230                         $options,
3231                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3232                 );
3233
3234                 $retVal = array();
3235                 if ( $res->numRows() ) {
3236                         $linkCache = LinkCache::singleton();
3237                         foreach ( $res as $row ) {
3238                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3239                                 if ( $titleObj ) {
3240                                         if ( $row->page_id ) {
3241                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3242                                         } else {
3243                                                 $linkCache->addBadLinkObj( $titleObj );
3244                                         }
3245                                         $retVal[] = $titleObj;
3246                                 }
3247                         }
3248                 }
3249                 return $retVal;
3250         }
3251
3252         /**
3253          * Get an array of Title objects used on this Title as a template
3254          * Also stores the IDs in the link cache.
3255          *
3256          * WARNING: do not use this function on arbitrary user-supplied titles!
3257          * On heavily-used templates it will max out the memory.
3258          *
3259          * @param $options Array: may be FOR UPDATE
3260          * @return Array of Title the Title objects used here
3261          */
3262         public function getTemplateLinksFrom( $options = array() ) {
3263                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3264         }
3265
3266         /**
3267          * Get an array of Title objects referring to non-existent articles linked from this page
3268          *
3269          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3270          * @return Array of Title the Title objects
3271          */
3272         public function getBrokenLinksFrom() {
3273                 if ( $this->getArticleID() == 0 ) {
3274                         # All links from article ID 0 are false positives
3275                         return array();
3276                 }
3277
3278                 $dbr = wfGetDB( DB_SLAVE );
3279                 $res = $dbr->select(
3280                         array( 'page', 'pagelinks' ),
3281                         array( 'pl_namespace', 'pl_title' ),
3282                         array(
3283                                 'pl_from' => $this->getArticleID(),
3284                                 'page_namespace IS NULL'
3285                         ),
3286                         __METHOD__, array(),
3287                         array(
3288                                 'page' => array(
3289                                         'LEFT JOIN',
3290                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3291                                 )
3292                         )
3293                 );
3294
3295                 $retVal = array();
3296                 foreach ( $res as $row ) {
3297                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3298                 }
3299                 return $retVal;
3300         }
3301
3302
3303         /**
3304          * Get a list of URLs to purge from the Squid cache when this
3305          * page changes
3306          *
3307          * @return Array of String the URLs
3308          */
3309         public function getSquidURLs() {
3310                 global $wgContLang;
3311
3312                 $urls = array(
3313                         $this->getInternalURL(),
3314                         $this->getInternalURL( 'action=history' )
3315                 );
3316
3317                 // purge variant urls as well
3318                 if ( $wgContLang->hasVariants() ) {
3319                         $variants = $wgContLang->getVariants();
3320                         foreach ( $variants as $vCode ) {
3321                                 $urls[] = $this->getInternalURL( '', $vCode );
3322                         }
3323                 }
3324
3325                 return $urls;
3326         }
3327
3328         /**
3329          * Purge all applicable Squid URLs
3330          */
3331         public function purgeSquid() {
3332                 global $wgUseSquid;
3333                 if ( $wgUseSquid ) {
3334                         $urls = $this->getSquidURLs();
3335                         $u = new SquidUpdate( $urls );
3336                         $u->doUpdate();
3337                 }
3338         }
3339
3340         /**
3341          * Move this page without authentication
3342          *
3343          * @param $nt Title the new page Title
3344          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3345          */
3346         public function moveNoAuth( &$nt ) {
3347                 return $this->moveTo( $nt, false );
3348         }
3349
3350         /**
3351          * Check whether a given move operation would be valid.
3352          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3353          *
3354          * @param $nt Title the new title
3355          * @param $auth Bool indicates whether $wgUser's permissions
3356          *  should be checked
3357          * @param $reason String is the log summary of the move, used for spam checking
3358          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3359          */
3360         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3361                 global $wgUser;
3362
3363                 $errors = array();
3364                 if ( !$nt ) {
3365                         // Normally we'd add this to $errors, but we'll get
3366                         // lots of syntax errors if $nt is not an object
3367                         return array( array( 'badtitletext' ) );
3368                 }
3369                 if ( $this->equals( $nt ) ) {
3370                         $errors[] = array( 'selfmove' );
3371                 }
3372                 if ( !$this->isMovable() ) {
3373                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3374                 }
3375                 if ( $nt->getInterwiki() != '' ) {
3376                         $errors[] = array( 'immobile-target-namespace-iw' );
3377                 }
3378                 if ( !$nt->isMovable() ) {
3379                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3380                 }
3381
3382                 $oldid = $this->getArticleID();
3383                 $newid = $nt->getArticleID();
3384
3385                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3386                         $errors[] = array( 'articleexists' );
3387                 }
3388                 if ( ( $this->getDBkey() == '' ) ||
3389                          ( !$oldid ) ||
3390                          ( $nt->getDBkey() == '' ) ) {
3391                         $errors[] = array( 'badarticleerror' );
3392                 }
3393
3394                 // Image-specific checks
3395                 if ( $this->getNamespace() == NS_FILE ) {
3396                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3397                 }
3398
3399                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3400                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3401                 }
3402
3403                 if ( $auth ) {
3404                         $errors = wfMergeErrorArrays( $errors,
3405                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3406                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3407                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3408                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3409                 }
3410
3411                 $match = EditPage::matchSummarySpamRegex( $reason );
3412                 if ( $match !== false ) {
3413                         // This is kind of lame, won't display nice
3414                         $errors[] = array( 'spamprotectiontext' );
3415                 }
3416
3417                 $err = null;
3418                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3419                         $errors[] = array( 'hookaborted', $err );
3420                 }
3421
3422                 # The move is allowed only if (1) the target doesn't exist, or
3423                 # (2) the target is a redirect to the source, and has no history
3424                 # (so we can undo bad moves right after they're done).
3425
3426                 if ( 0 != $newid ) { # Target exists; check for validity
3427                         if ( !$this->isValidMoveTarget( $nt ) ) {
3428                                 $errors[] = array( 'articleexists' );
3429                         }
3430                 } else {
3431                         $tp = $nt->getTitleProtection();
3432                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3433                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3434                                 $errors[] = array( 'cantmove-titleprotected' );
3435                         }
3436                 }
3437                 if ( empty( $errors ) ) {
3438                         return true;
3439                 }
3440                 return $errors;
3441         }
3442
3443         /**
3444          * Check if the requested move target is a valid file move target
3445          * @param Title $nt Target title
3446          * @return array List of errors
3447          */
3448         protected function validateFileMoveOperation( $nt ) {
3449                 global $wgUser;
3450
3451                 $errors = array();
3452
3453                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3454
3455                 $file = wfLocalFile( $this );
3456                 if ( $file->exists() ) {
3457                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3458                                 $errors[] = array( 'imageinvalidfilename' );
3459                         }
3460                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3461                                 $errors[] = array( 'imagetypemismatch' );
3462                         }
3463                 }
3464
3465                 if ( $nt->getNamespace() != NS_FILE ) {
3466                         $errors[] = array( 'imagenocrossnamespace' );
3467                         // From here we want to do checks on a file object, so if we can't
3468                         // create one, we must return.
3469                         return $errors;
3470                 }
3471
3472                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3473
3474                 $destFile = wfLocalFile( $nt );
3475                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3476                         $errors[] = array( 'file-exists-sharedrepo' );
3477                 }
3478
3479                 return $errors;
3480         }
3481
3482         /**
3483          * Move a title to a new location
3484          *
3485          * @param $nt Title the new title
3486          * @param $auth Bool indicates whether $wgUser's permissions
3487          *  should be checked
3488          * @param $reason String the reason for the move
3489          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3490          *  Ignored if the user doesn't have the suppressredirect right.
3491          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3492          */
3493         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3494                 global $wgUser;
3495                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3496                 if ( is_array( $err ) ) {
3497                         // Auto-block user's IP if the account was "hard" blocked
3498                         $wgUser->spreadAnyEditBlock();
3499                         return $err;
3500                 }
3501
3502                 // If it is a file, move it first.
3503                 // It is done before all other moving stuff is done because it's hard to revert.
3504                 $dbw = wfGetDB( DB_MASTER );
3505                 if ( $this->getNamespace() == NS_FILE ) {
3506                         $file = wfLocalFile( $this );
3507                         if ( $file->exists() ) {
3508                                 $status = $file->move( $nt );
3509                                 if ( !$status->isOk() ) {
3510                                         return $status->getErrorsArray();
3511                                 }
3512                         }
3513                         // Clear RepoGroup process cache
3514                         RepoGroup::singleton()->clearCache( $this );
3515                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3516                 }
3517
3518                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3519                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3520                 $protected = $this->isProtected();
3521
3522                 // Do the actual move
3523                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3524                 if ( is_array( $err ) ) {
3525                         # @todo FIXME: What about the File we have already moved?
3526                         $dbw->rollback( __METHOD__ );
3527                         return $err;
3528                 }
3529
3530                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3531                 // cl_timestamp, which may disturb time-based lists on some sites.
3532                 $prefixes = $dbw->select(
3533                         'categorylinks',
3534                         array( 'cl_sortkey_prefix', 'cl_to' ),
3535                         array( 'cl_from' => $pageid ),
3536                         __METHOD__
3537                 );
3538                 foreach ( $prefixes as $prefixRow ) {
3539                         $prefix = $prefixRow->cl_sortkey_prefix;
3540                         $catTo = $prefixRow->cl_to;
3541                         $dbw->update( 'categorylinks',
3542                                 array(
3543                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3544                                                 $nt->getCategorySortkey( $prefix ) ),
3545                                         'cl_timestamp=cl_timestamp' ),
3546                                 array(
3547                                         'cl_from' => $pageid,
3548                                         'cl_to' => $catTo ),
3549                                 __METHOD__
3550                         );
3551                 }
3552
3553                 $redirid = $this->getArticleID();
3554
3555                 if ( $protected ) {
3556                         # Protect the redirect title as the title used to be...
3557                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3558                                 array(
3559                                         'pr_page'    => $redirid,
3560                                         'pr_type'    => 'pr_type',
3561                                         'pr_level'   => 'pr_level',
3562                                         'pr_cascade' => 'pr_cascade',
3563                                         'pr_user'    => 'pr_user',
3564                                         'pr_expiry'  => 'pr_expiry'
3565                                 ),
3566                                 array( 'pr_page' => $pageid ),
3567                                 __METHOD__,
3568                                 array( 'IGNORE' )
3569                         );
3570                         # Update the protection log
3571                         $log = new LogPage( 'protect' );
3572                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3573                         if ( $reason ) {
3574                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3575                         }
3576                         // @todo FIXME: $params?
3577                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3578                 }
3579
3580                 # Update watchlists
3581                 $oldnamespace = $this->getNamespace() & ~1;
3582                 $newnamespace = $nt->getNamespace() & ~1;
3583                 $oldtitle = $this->getDBkey();
3584                 $newtitle = $nt->getDBkey();
3585
3586                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3587                         WatchedItem::duplicateEntries( $this, $nt );
3588                 }
3589
3590                 $dbw->commit( __METHOD__ );
3591
3592                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3593                 return true;
3594         }
3595
3596         /**
3597          * Move page to a title which is either a redirect to the
3598          * source page or nonexistent
3599          *
3600          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3601          * @param $reason String The reason for the move
3602          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3603          *   if the user doesn't have the suppressredirect right
3604          */
3605         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3606                 global $wgUser, $wgContLang;
3607
3608                 if ( $nt->exists() ) {
3609                         $moveOverRedirect = true;
3610                         $logType = 'move_redir';
3611                 } else {
3612                         $moveOverRedirect = false;
3613                         $logType = 'move';
3614                 }
3615
3616                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3617
3618                 $logEntry = new ManualLogEntry( 'move', $logType );
3619                 $logEntry->setPerformer( $wgUser );
3620                 $logEntry->setTarget( $this );
3621                 $logEntry->setComment( $reason );
3622                 $logEntry->setParameters( array(
3623                         '4::target' => $nt->getPrefixedText(),
3624                         '5::noredir' => $redirectSuppressed ? '1': '0',
3625                 ) );
3626
3627                 $formatter = LogFormatter::newFromEntry( $logEntry );
3628                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3629                 $comment = $formatter->getPlainActionText();
3630                 if ( $reason ) {
3631                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3632                 }
3633                 # Truncate for whole multibyte characters.
3634                 $comment = $wgContLang->truncate( $comment, 255 );
3635
3636                 $oldid = $this->getArticleID();
3637
3638                 $dbw = wfGetDB( DB_MASTER );
3639
3640                 $newpage = WikiPage::factory( $nt );
3641
3642                 if ( $moveOverRedirect ) {
3643                         $newid = $nt->getArticleID();
3644
3645                         # Delete the old redirect. We don't save it to history since
3646                         # by definition if we've got here it's rather uninteresting.
3647                         # We have to remove it so that the next step doesn't trigger
3648                         # a conflict on the unique namespace+title index...
3649                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3650
3651                         $newpage->doDeleteUpdates( $newid );
3652                 }
3653
3654                 # Save a null revision in the page's history notifying of the move
3655                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3656                 if ( !is_object( $nullRevision ) ) {
3657                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3658                 }
3659                 $nullRevId = $nullRevision->insertOn( $dbw );
3660
3661                 # Change the name of the target page:
3662                 $dbw->update( 'page',
3663                         /* SET */ array(
3664                                 'page_namespace' => $nt->getNamespace(),
3665                                 'page_title'     => $nt->getDBkey(),
3666                         ),
3667                         /* WHERE */ array( 'page_id' => $oldid ),
3668                         __METHOD__
3669                 );
3670
3671                 $this->resetArticleID( 0 );
3672                 $nt->resetArticleID( $oldid );
3673
3674                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3675
3676                 wfRunHooks( 'NewRevisionFromEditComplete',
3677                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3678
3679                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3680
3681                 if ( !$moveOverRedirect ) {
3682                         WikiPage::onArticleCreate( $nt );
3683                 }
3684
3685                 # Recreate the redirect, this time in the other direction.
3686                 if ( $redirectSuppressed ) {
3687                         WikiPage::onArticleDelete( $this );
3688                 } else {
3689                         $mwRedir = MagicWord::get( 'redirect' );
3690                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3691                         $redirectArticle = WikiPage::factory( $this );
3692                         $newid = $redirectArticle->insertOn( $dbw );
3693                         if ( $newid ) { // sanity
3694                                 $redirectRevision = new Revision( array(
3695                                         'page'    => $newid,
3696                                         'comment' => $comment,
3697                                         'text'    => $redirectText ) );
3698                                 $redirectRevision->insertOn( $dbw );
3699                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3700
3701                                 wfRunHooks( 'NewRevisionFromEditComplete',
3702                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3703
3704                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3705                         }
3706                 }
3707
3708                 # Log the move
3709                 $logid = $logEntry->insert();
3710                 $logEntry->publish( $logid );
3711         }
3712
3713         /**
3714          * Move this page's subpages to be subpages of $nt
3715          *
3716          * @param $nt Title Move target
3717          * @param $auth bool Whether $wgUser's permissions should be checked
3718          * @param $reason string The reason for the move
3719          * @param $createRedirect bool Whether to create redirects from the old subpages to
3720          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3721          * @return mixed array with old page titles as keys, and strings (new page titles) or
3722          *     arrays (errors) as values, or an error array with numeric indices if no pages
3723          *     were moved
3724          */
3725         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3726                 global $wgMaximumMovedPages;
3727                 // Check permissions
3728                 if ( !$this->userCan( 'move-subpages' ) ) {
3729                         return array( 'cant-move-subpages' );
3730                 }
3731                 // Do the source and target namespaces support subpages?
3732                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3733                         return array( 'namespace-nosubpages',
3734                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3735                 }
3736                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3737                         return array( 'namespace-nosubpages',
3738                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3739                 }
3740
3741                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3742                 $retval = array();
3743                 $count = 0;
3744                 foreach ( $subpages as $oldSubpage ) {
3745                         $count++;
3746                         if ( $count > $wgMaximumMovedPages ) {
3747                                 $retval[$oldSubpage->getPrefixedTitle()] =
3748                                                 array( 'movepage-max-pages',
3749                                                         $wgMaximumMovedPages );
3750                                 break;
3751                         }
3752
3753                         // We don't know whether this function was called before
3754                         // or after moving the root page, so check both
3755                         // $this and $nt
3756                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3757                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3758                         {
3759                                 // When moving a page to a subpage of itself,
3760                                 // don't move it twice
3761                                 continue;
3762                         }
3763                         $newPageName = preg_replace(
3764                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3765                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3766                                         $oldSubpage->getDBkey() );
3767                         if ( $oldSubpage->isTalkPage() ) {
3768                                 $newNs = $nt->getTalkPage()->getNamespace();
3769                         } else {
3770                                 $newNs = $nt->getSubjectPage()->getNamespace();
3771                         }
3772                         # Bug 14385: we need makeTitleSafe because the new page names may
3773                         # be longer than 255 characters.
3774                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3775
3776                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3777                         if ( $success === true ) {
3778                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3779                         } else {
3780                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3781                         }
3782                 }
3783                 return $retval;
3784         }
3785
3786         /**
3787          * Checks if this page is just a one-rev redirect.
3788          * Adds lock, so don't use just for light purposes.
3789          *
3790          * @return Bool
3791          */
3792         public function isSingleRevRedirect() {
3793                 $dbw = wfGetDB( DB_MASTER );
3794                 # Is it a redirect?
3795                 $row = $dbw->selectRow( 'page',
3796                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3797                         $this->pageCond(),
3798                         __METHOD__,
3799                         array( 'FOR UPDATE' )
3800                 );
3801                 # Cache some fields we may want
3802                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3803                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3804                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3805                 if ( !$this->mRedirect ) {
3806                         return false;
3807                 }
3808                 # Does the article have a history?
3809                 $row = $dbw->selectField( array( 'page', 'revision' ),
3810                         'rev_id',
3811                         array( 'page_namespace' => $this->getNamespace(),
3812                                 'page_title' => $this->getDBkey(),
3813                                 'page_id=rev_page',
3814                                 'page_latest != rev_id'
3815                         ),
3816                         __METHOD__,
3817                         array( 'FOR UPDATE' )
3818                 );
3819                 # Return true if there was no history
3820                 return ( $row === false );
3821         }
3822
3823         /**
3824          * Checks if $this can be moved to a given Title
3825          * - Selects for update, so don't call it unless you mean business
3826          *
3827          * @param $nt Title the new title to check
3828          * @return Bool
3829          */
3830         public function isValidMoveTarget( $nt ) {
3831                 # Is it an existing file?
3832                 if ( $nt->getNamespace() == NS_FILE ) {
3833                         $file = wfLocalFile( $nt );
3834                         if ( $file->exists() ) {
3835                                 wfDebug( __METHOD__ . ": file exists\n" );
3836                                 return false;
3837                         }
3838                 }
3839                 # Is it a redirect with no history?
3840                 if ( !$nt->isSingleRevRedirect() ) {
3841                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3842                         return false;
3843                 }
3844                 # Get the article text
3845                 $rev = Revision::newFromTitle( $nt );
3846                 if( !is_object( $rev ) ){
3847                         return false;
3848                 }
3849                 $text = $rev->getText();
3850                 # Does the redirect point to the source?
3851                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3852                 $m = array();
3853                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3854                         $redirTitle = Title::newFromText( $m[1] );
3855                         if ( !is_object( $redirTitle ) ||
3856                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3857                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3858                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3859                                 return false;
3860                         }
3861                 } else {
3862                         # Fail safe
3863                         wfDebug( __METHOD__ . ": failsafe\n" );
3864                         return false;
3865                 }
3866                 return true;
3867         }
3868
3869         /**
3870          * Get categories to which this Title belongs and return an array of
3871          * categories' names.
3872          *
3873          * @return Array of parents in the form:
3874          *        $parent => $currentarticle
3875          */
3876         public function getParentCategories() {
3877                 global $wgContLang;
3878
3879                 $data = array();
3880
3881                 $titleKey = $this->getArticleID();
3882
3883                 if ( $titleKey === 0 ) {
3884                         return $data;
3885                 }
3886
3887                 $dbr = wfGetDB( DB_SLAVE );
3888
3889                 $res = $dbr->select( 'categorylinks', '*',
3890                         array(
3891                                 'cl_from' => $titleKey,
3892                         ),
3893                         __METHOD__,
3894                         array()
3895                 );
3896
3897                 if ( $dbr->numRows( $res ) > 0 ) {
3898                         foreach ( $res as $row ) {
3899                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3900                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3901                         }
3902                 }
3903                 return $data;
3904         }
3905
3906         /**
3907          * Get a tree of parent categories
3908          *
3909          * @param $children Array with the children in the keys, to check for circular refs
3910          * @return Array Tree of parent categories
3911          */
3912         public function getParentCategoryTree( $children = array() ) {
3913                 $stack = array();
3914                 $parents = $this->getParentCategories();
3915
3916                 if ( $parents ) {
3917                         foreach ( $parents as $parent => $current ) {
3918                                 if ( array_key_exists( $parent, $children ) ) {
3919                                         # Circular reference
3920                                         $stack[$parent] = array();
3921                                 } else {
3922                                         $nt = Title::newFromText( $parent );
3923                                         if ( $nt ) {
3924                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3925                                         }
3926                                 }
3927                         }
3928                 }
3929
3930                 return $stack;
3931         }
3932
3933         /**
3934          * Get an associative array for selecting this title from
3935          * the "page" table
3936          *
3937          * @return Array suitable for the $where parameter of DB::select()
3938          */
3939         public function pageCond() {
3940                 if ( $this->mArticleID > 0 ) {
3941                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3942                         return array( 'page_id' => $this->mArticleID );
3943                 } else {
3944                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3945                 }
3946         }
3947
3948         /**
3949          * Get the revision ID of the previous revision
3950          *
3951          * @param $revId Int Revision ID. Get the revision that was before this one.
3952          * @param $flags Int Title::GAID_FOR_UPDATE
3953          * @return Int|Bool Old revision ID, or FALSE if none exists
3954          */
3955         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3956                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3957                 return $db->selectField( 'revision', 'rev_id',
3958                         array(
3959                                 'rev_page' => $this->getArticleID( $flags ),
3960                                 'rev_id < ' . intval( $revId )
3961                         ),
3962                         __METHOD__,
3963                         array( 'ORDER BY' => 'rev_id DESC' )
3964                 );
3965         }
3966
3967         /**
3968          * Get the revision ID of the next revision
3969          *
3970          * @param $revId Int Revision ID. Get the revision that was after this one.
3971          * @param $flags Int Title::GAID_FOR_UPDATE
3972          * @return Int|Bool Next revision ID, or FALSE if none exists
3973          */
3974         public function getNextRevisionID( $revId, $flags = 0 ) {
3975                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3976                 return $db->selectField( 'revision', 'rev_id',
3977                         array(
3978                                 'rev_page' => $this->getArticleID( $flags ),
3979                                 'rev_id > ' . intval( $revId )
3980                         ),
3981                         __METHOD__,
3982                         array( 'ORDER BY' => 'rev_id' )
3983                 );
3984         }
3985
3986         /**
3987          * Get the first revision of the page
3988          *
3989          * @param $flags Int Title::GAID_FOR_UPDATE
3990          * @return Revision|Null if page doesn't exist
3991          */
3992         public function getFirstRevision( $flags = 0 ) {
3993                 $pageId = $this->getArticleID( $flags );
3994                 if ( $pageId ) {
3995                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3996                         $row = $db->selectRow( 'revision', '*',
3997                                 array( 'rev_page' => $pageId ),
3998                                 __METHOD__,
3999                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4000                         );
4001                         if ( $row ) {
4002                                 return new Revision( $row );
4003                         }
4004                 }
4005                 return null;
4006         }
4007
4008         /**
4009          * Get the oldest revision timestamp of this page
4010          *
4011          * @param $flags Int Title::GAID_FOR_UPDATE
4012          * @return String: MW timestamp
4013          */
4014         public function getEarliestRevTime( $flags = 0 ) {
4015                 $rev = $this->getFirstRevision( $flags );
4016                 return $rev ? $rev->getTimestamp() : null;
4017         }
4018
4019         /**
4020          * Check if this is a new page
4021          *
4022          * @return bool
4023          */
4024         public function isNewPage() {
4025                 $dbr = wfGetDB( DB_SLAVE );
4026                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4027         }
4028
4029         /**
4030          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4031          *
4032          * @return bool
4033          */
4034         public function isBigDeletion() {
4035                 global $wgDeleteRevisionsLimit;
4036
4037                 if ( !$wgDeleteRevisionsLimit ) {
4038                         return false;
4039                 }
4040
4041                 $revCount = $this->estimateRevisionCount();
4042                 return $revCount > $wgDeleteRevisionsLimit;
4043         }
4044
4045         /**
4046          * Get the  approximate revision count of this page.
4047          *
4048          * @return int
4049          */
4050         public function estimateRevisionCount() {
4051                 if ( !$this->exists() ) {
4052                         return 0;
4053                 }
4054
4055                 if ( $this->mEstimateRevisions === null ) {
4056                         $dbr = wfGetDB( DB_SLAVE );
4057                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4058                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4059                 }
4060
4061                 return $this->mEstimateRevisions;
4062         }
4063
4064         /**
4065          * Get the number of revisions between the given revision.
4066          * Used for diffs and other things that really need it.
4067          *
4068          * @param $old int|Revision Old revision or rev ID (first before range)
4069          * @param $new int|Revision New revision or rev ID (first after range)
4070          * @return Int Number of revisions between these revisions.
4071          */
4072         public function countRevisionsBetween( $old, $new ) {
4073                 if ( !( $old instanceof Revision ) ) {
4074                         $old = Revision::newFromTitle( $this, (int)$old );
4075                 }
4076                 if ( !( $new instanceof Revision ) ) {
4077                         $new = Revision::newFromTitle( $this, (int)$new );
4078                 }
4079                 if ( !$old || !$new ) {
4080                         return 0; // nothing to compare
4081                 }
4082                 $dbr = wfGetDB( DB_SLAVE );
4083                 return (int)$dbr->selectField( 'revision', 'count(*)',
4084                         array(
4085                                 'rev_page' => $this->getArticleID(),
4086                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4087                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4088                         ),
4089                         __METHOD__
4090                 );
4091         }
4092
4093         /**
4094          * Get the number of authors between the given revision IDs.
4095          * Used for diffs and other things that really need it.
4096          *
4097          * @param $old int|Revision Old revision or rev ID (first before range)
4098          * @param $new int|Revision New revision or rev ID (first after range)
4099          * @param $limit Int Maximum number of authors
4100          * @return Int Number of revision authors between these revisions.
4101          */
4102         public function countAuthorsBetween( $old, $new, $limit ) {
4103                 if ( !( $old instanceof Revision ) ) {
4104                         $old = Revision::newFromTitle( $this, (int)$old );
4105                 }
4106                 if ( !( $new instanceof Revision ) ) {
4107                         $new = Revision::newFromTitle( $this, (int)$new );
4108                 }
4109                 if ( !$old || !$new ) {
4110                         return 0; // nothing to compare
4111                 }
4112                 $dbr = wfGetDB( DB_SLAVE );
4113                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4114                         array(
4115                                 'rev_page' => $this->getArticleID(),
4116                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4117                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4118                         ), __METHOD__,
4119                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4120                 );
4121                 return (int)$dbr->numRows( $res );
4122         }
4123
4124         /**
4125          * Compare with another title.
4126          *
4127          * @param $title Title
4128          * @return Bool
4129          */
4130         public function equals( Title $title ) {
4131                 // Note: === is necessary for proper matching of number-like titles.
4132                 return $this->getInterwiki() === $title->getInterwiki()
4133                         && $this->getNamespace() == $title->getNamespace()
4134                         && $this->getDBkey() === $title->getDBkey();
4135         }
4136
4137         /**
4138          * Check if this title is a subpage of another title
4139          *
4140          * @param $title Title
4141          * @return Bool
4142          */
4143         public function isSubpageOf( Title $title ) {
4144                 return $this->getInterwiki() === $title->getInterwiki()
4145                         && $this->getNamespace() == $title->getNamespace()
4146                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4147         }
4148
4149         /**
4150          * Check if page exists.  For historical reasons, this function simply
4151          * checks for the existence of the title in the page table, and will
4152          * thus return false for interwiki links, special pages and the like.
4153          * If you want to know if a title can be meaningfully viewed, you should
4154          * probably call the isKnown() method instead.
4155          *
4156          * @return Bool
4157          */
4158         public function exists() {
4159                 return $this->getArticleID() != 0;
4160         }
4161
4162         /**
4163          * Should links to this title be shown as potentially viewable (i.e. as
4164          * "bluelinks"), even if there's no record by this title in the page
4165          * table?
4166          *
4167          * This function is semi-deprecated for public use, as well as somewhat
4168          * misleadingly named.  You probably just want to call isKnown(), which
4169          * calls this function internally.
4170          *
4171          * (ISSUE: Most of these checks are cheap, but the file existence check
4172          * can potentially be quite expensive.  Including it here fixes a lot of
4173          * existing code, but we might want to add an optional parameter to skip
4174          * it and any other expensive checks.)
4175          *
4176          * @return Bool
4177          */
4178         public function isAlwaysKnown() {
4179                 $isKnown = null;
4180
4181                 /**
4182                  * Allows overriding default behaviour for determining if a page exists.
4183                  * If $isKnown is kept as null, regular checks happen. If it's
4184                  * a boolean, this value is returned by the isKnown method.
4185                  *
4186                  * @since 1.20
4187                  *
4188                  * @param Title $title
4189                  * @param boolean|null $isKnown
4190                  */
4191                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4192
4193                 if ( !is_null( $isKnown ) ) {
4194                         return $isKnown;
4195                 }
4196
4197                 if ( $this->mInterwiki != '' ) {
4198                         return true;  // any interwiki link might be viewable, for all we know
4199                 }
4200
4201                 switch( $this->mNamespace ) {
4202                         case NS_MEDIA:
4203                         case NS_FILE:
4204                                 // file exists, possibly in a foreign repo
4205                                 return (bool)wfFindFile( $this );
4206                         case NS_SPECIAL:
4207                                 // valid special page
4208                                 return SpecialPageFactory::exists( $this->getDBkey() );
4209                         case NS_MAIN:
4210                                 // selflink, possibly with fragment
4211                                 return $this->mDbkeyform == '';
4212                         case NS_MEDIAWIKI:
4213                                 // known system message
4214                                 return $this->hasSourceText() !== false;
4215                         default:
4216                                 return false;
4217                 }
4218         }
4219
4220         /**
4221          * Does this title refer to a page that can (or might) be meaningfully
4222          * viewed?  In particular, this function may be used to determine if
4223          * links to the title should be rendered as "bluelinks" (as opposed to
4224          * "redlinks" to non-existent pages).
4225          * Adding something else to this function will cause inconsistency
4226          * since LinkHolderArray calls isAlwaysKnown() and does its own
4227          * page existence check.
4228          *
4229          * @return Bool
4230          */
4231         public function isKnown() {
4232                 return $this->isAlwaysKnown() || $this->exists();
4233         }
4234
4235         /**
4236          * Does this page have source text?
4237          *
4238          * @return Boolean
4239          */
4240         public function hasSourceText() {
4241                 if ( $this->exists() ) {
4242                         return true;
4243                 }
4244
4245                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4246                         // If the page doesn't exist but is a known system message, default
4247                         // message content will be displayed, same for language subpages-
4248                         // Use always content language to avoid loading hundreds of languages
4249                         // to get the link color.
4250                         global $wgContLang;
4251                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4252                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4253                         return $message->exists();
4254                 }
4255
4256                 return false;
4257         }
4258
4259         /**
4260          * Get the default message text or false if the message doesn't exist
4261          *
4262          * @return String or false
4263          */
4264         public function getDefaultMessageText() {
4265                 global $wgContLang;
4266
4267                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4268                         return false;
4269                 }
4270
4271                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4272                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4273
4274                 if ( $message->exists() ) {
4275                         return $message->plain();
4276                 } else {
4277                         return false;
4278                 }
4279         }
4280
4281         /**
4282          * Updates page_touched for this page; called from LinksUpdate.php
4283          *
4284          * @return Bool true if the update succeded
4285          */
4286         public function invalidateCache() {
4287                 if ( wfReadOnly() ) {
4288                         return false;
4289                 }
4290                 $dbw = wfGetDB( DB_MASTER );
4291                 $success = $dbw->update(
4292                         'page',
4293                         array( 'page_touched' => $dbw->timestamp() ),
4294                         $this->pageCond(),
4295                         __METHOD__
4296                 );
4297                 HTMLFileCache::clearFileCache( $this );
4298                 return $success;
4299         }
4300
4301         /**
4302          * Update page_touched timestamps and send squid purge messages for
4303          * pages linking to this title. May be sent to the job queue depending
4304          * on the number of links. Typically called on create and delete.
4305          */
4306         public function touchLinks() {
4307                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4308                 $u->doUpdate();
4309
4310                 if ( $this->getNamespace() == NS_CATEGORY ) {
4311                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4312                         $u->doUpdate();
4313                 }
4314         }
4315
4316         /**
4317          * Get the last touched timestamp
4318          *
4319          * @param $db DatabaseBase: optional db
4320          * @return String last-touched timestamp
4321          */
4322         public function getTouched( $db = null ) {
4323                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4324                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4325                 return $touched;
4326         }
4327
4328         /**
4329          * Get the timestamp when this page was updated since the user last saw it.
4330          *
4331          * @param $user User
4332          * @return String|Null
4333          */
4334         public function getNotificationTimestamp( $user = null ) {
4335                 global $wgUser, $wgShowUpdatedMarker;
4336                 // Assume current user if none given
4337                 if ( !$user ) {
4338                         $user = $wgUser;
4339                 }
4340                 // Check cache first
4341                 $uid = $user->getId();
4342                 // avoid isset here, as it'll return false for null entries
4343                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4344                         return $this->mNotificationTimestamp[$uid];
4345                 }
4346                 if ( !$uid || !$wgShowUpdatedMarker ) {
4347                         return $this->mNotificationTimestamp[$uid] = false;
4348                 }
4349                 // Don't cache too much!
4350                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4351                         $this->mNotificationTimestamp = array();
4352                 }
4353                 $dbr = wfGetDB( DB_SLAVE );
4354                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4355                         'wl_notificationtimestamp',
4356                         array( 'wl_namespace' => $this->getNamespace(),
4357                                 'wl_title' => $this->getDBkey(),
4358                                 'wl_user' => $user->getId()
4359                         ),
4360                         __METHOD__
4361                 );
4362                 return $this->mNotificationTimestamp[$uid];
4363         }
4364
4365         /**
4366          * Generate strings used for xml 'id' names in monobook tabs
4367          *
4368          * @param $prepend string defaults to 'nstab-'
4369          * @return String XML 'id' name
4370          */
4371         public function getNamespaceKey( $prepend = 'nstab-' ) {
4372                 global $wgContLang;
4373                 // Gets the subject namespace if this title
4374                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4375                 // Checks if cononical namespace name exists for namespace
4376                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4377                         // Uses canonical namespace name
4378                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4379                 } else {
4380                         // Uses text of namespace
4381                         $namespaceKey = $this->getSubjectNsText();
4382                 }
4383                 // Makes namespace key lowercase
4384                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4385                 // Uses main
4386                 if ( $namespaceKey == '' ) {
4387                         $namespaceKey = 'main';
4388                 }
4389                 // Changes file to image for backwards compatibility
4390                 if ( $namespaceKey == 'file' ) {
4391                         $namespaceKey = 'image';
4392                 }
4393                 return $prepend . $namespaceKey;
4394         }
4395
4396         /**
4397          * Get all extant redirects to this Title
4398          *
4399          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4400          * @return Array of Title redirects to this title
4401          */
4402         public function getRedirectsHere( $ns = null ) {
4403                 $redirs = array();
4404
4405                 $dbr = wfGetDB( DB_SLAVE );
4406                 $where = array(
4407                         'rd_namespace' => $this->getNamespace(),
4408                         'rd_title' => $this->getDBkey(),
4409                         'rd_from = page_id'
4410                 );
4411                 if ( !is_null( $ns ) ) {
4412                         $where['page_namespace'] = $ns;
4413                 }
4414
4415                 $res = $dbr->select(
4416                         array( 'redirect', 'page' ),
4417                         array( 'page_namespace', 'page_title' ),
4418                         $where,
4419                         __METHOD__
4420                 );
4421
4422                 foreach ( $res as $row ) {
4423                         $redirs[] = self::newFromRow( $row );
4424                 }
4425                 return $redirs;
4426         }
4427
4428         /**
4429          * Check if this Title is a valid redirect target
4430          *
4431          * @return Bool
4432          */
4433         public function isValidRedirectTarget() {
4434                 global $wgInvalidRedirectTargets;
4435
4436                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4437                 if ( $this->isSpecial( 'Userlogout' ) ) {
4438                         return false;
4439                 }
4440
4441                 foreach ( $wgInvalidRedirectTargets as $target ) {
4442                         if ( $this->isSpecial( $target ) ) {
4443                                 return false;
4444                         }
4445                 }
4446
4447                 return true;
4448         }
4449
4450         /**
4451          * Get a backlink cache object
4452          *
4453          * @return BacklinkCache
4454          */
4455         function getBacklinkCache() {
4456                 if ( is_null( $this->mBacklinkCache ) ) {
4457                         $this->mBacklinkCache = new BacklinkCache( $this );
4458                 }
4459                 return $this->mBacklinkCache;
4460         }
4461
4462         /**
4463          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4464          *
4465          * @return Boolean
4466          */
4467         public function canUseNoindex() {
4468                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4469
4470                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4471                         ? $wgContentNamespaces
4472                         : $wgExemptFromUserRobotsControl;
4473
4474                 return !in_array( $this->mNamespace, $bannedNamespaces );
4475
4476         }
4477
4478         /**
4479          * Returns the raw sort key to be used for categories, with the specified
4480          * prefix.  This will be fed to Collation::getSortKey() to get a
4481          * binary sortkey that can be used for actual sorting.
4482          *
4483          * @param $prefix string The prefix to be used, specified using
4484          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4485          *   prefix.
4486          * @return string
4487          */
4488         public function getCategorySortkey( $prefix = '' ) {
4489                 $unprefixed = $this->getText();
4490
4491                 // Anything that uses this hook should only depend
4492                 // on the Title object passed in, and should probably
4493                 // tell the users to run updateCollations.php --force
4494                 // in order to re-sort existing category relations.
4495                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4496                 if ( $prefix !== '' ) {
4497                         # Separate with a line feed, so the unprefixed part is only used as
4498                         # a tiebreaker when two pages have the exact same prefix.
4499                         # In UCA, tab is the only character that can sort above LF
4500                         # so we strip both of them from the original prefix.
4501                         $prefix = strtr( $prefix, "\n\t", '  ' );
4502                         return "$prefix\n$unprefixed";
4503                 }
4504                 return $unprefixed;
4505         }
4506
4507         /**
4508          * Get the language in which the content of this page is written.
4509          * Defaults to $wgContLang, but in certain cases it can be e.g.
4510          * $wgLang (such as special pages, which are in the user language).
4511          *
4512          * @since 1.18
4513          * @return object Language
4514          */
4515         public function getPageLanguage() {
4516                 global $wgLang;
4517                 if ( $this->isSpecialPage() ) {
4518                         // special pages are in the user language
4519                         return $wgLang;
4520                 } elseif ( $this->isCssOrJsPage() || $this->isCssJsSubpage() ) {
4521                         // css/js should always be LTR and is, in fact, English
4522                         return wfGetLangObj( 'en' );
4523                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4524                         // Parse mediawiki messages with correct target language
4525                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4526                         return wfGetLangObj( $lang );
4527                 }
4528                 global $wgContLang;
4529                 // If nothing special, it should be in the wiki content language
4530                 $pageLang = $wgContLang;
4531                 // Hook at the end because we don't want to override the above stuff
4532                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4533                 return wfGetLangObj( $pageLang );
4534         }
4535 }