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         /**
  52          * @name Private member variables
  53          * Please use the accessor functions instead.
  54          * @private
  55          */
  56         // @{
  57
  58         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  59         var $mUrlform = '';               // /< URL-encoded form of the main part
  60         var $mDbkeyform = '';             // /< Main part with underscores
  61         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  62         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  63         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  64         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  65         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  66         var $mLatestID = false;           // /< ID of most recent revision
  67         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  68         var $mOldRestrictions = false;
  69         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  70         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  71         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  72         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  73         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  74         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  75         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  76         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  77         # Don't change the following default, NS_MAIN is hardcoded in several
  78         # places.  See bug 696.
  79         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  80                                                                           # Zero except in {{transclusion}} tags
  81         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  82         var $mLength = -1;                // /< The page length, 0 for special pages
  83         var $mRedirect = null;            // /< Is the article at this title a redirect?
  84         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  85         var $mBacklinkCache = null;       // /< Cache of links to this title
  86         // @}
  87
  88
  89         /**
  90          * Constructor
  91          */
  92         /*protected*/ function __construct() { }
  93
  94         /**
  95          * Create a new Title from a prefixed DB key
  96          *
  97          * @param $key String the database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return Title, or NULL on an error
 101          */
 102         public static function newFromDBkey( $key ) {
 103                 $t = new Title();
 104                 $t->mDbkeyform = $key;
 105                 if ( $t->secureAndSplit() ) {
 106                         return $t;
 107                 } else {
 108                         return null;
 109                 }
 110         }
 111
 112         /**
 113          * Create a new Title from text, such as what one would find in a link. De-
 114          * codes any HTML entities in the text.
 115          *
 116          * @param $text String the link text; spaces, prefixes, and an
 117          *   initial ':' indicating the main namespace are accepted.
 118          * @param $defaultNamespace Int the namespace to use if none is speci-
 119          *   fied by a prefix.  If you want to force a specific namespace even if
 120          *   $text might begin with a namespace prefix, use makeTitle() or
 121          *   makeTitleSafe().
 122          * @return Title, or null on an error.
 123          */
 124         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 125                 if ( is_object( $text ) ) {
 126                         throw new MWException( 'Title::newFromText given an object' );
 127                 }
 128
 129                 /**
 130                  * Wiki pages often contain multiple links to the same page.
 131                  * Title normalization and parsing can become expensive on
 132                  * pages with many links, so we can save a little time by
 133                  * caching them.
 134                  *
 135                  * In theory these are value objects and won't get changed...
 136                  */
 137                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 138                         return Title::$titleCache[$text];
 139                 }
 140
 141                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 142                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 143
 144                 $t = new Title();
 145                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 146                 $t->mDefaultNamespace = $defaultNamespace;
 147
 148                 static $cachedcount = 0 ;
 149                 if ( $t->secureAndSplit() ) {
 150                         if ( $defaultNamespace == NS_MAIN ) {
 151                                 if ( $cachedcount >= self::CACHE_MAX ) {
 152                                         # Avoid memory leaks on mass operations...
 153                                         Title::$titleCache = array();
 154                                         $cachedcount = 0;
 155                                 }
 156                                 $cachedcount++;
 157                                 Title::$titleCache[$text] =& $t;
 158                         }
 159                         return $t;
 160                 } else {
 161                         $ret = null;
 162                         return $ret;
 163                 }
 164         }
 165
 166         /**
 167          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 168          *
 169          * Example of wrong and broken code:
 170          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 171          *
 172          * Example of right code:
 173          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Create a new Title from URL-encoded text. Ensures that
 176          * the given title's length does not exceed the maximum.
 177          *
 178          * @param $url String the title, as might be taken from a URL
 179          * @return Title the new object, or NULL on an error
 180          */
 181         public static function newFromURL( $url ) {
 182                 global $wgLegalTitleChars;
 183                 $t = new Title();
 184
 185                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 186                 # but some URLs used it as a space replacement and they still come
 187                 # from some external search tools.
 188                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 189                         $url = str_replace( '+', ' ', $url );
 190                 }
 191
 192                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 193                 if ( $t->secureAndSplit() ) {
 194                         return $t;
 195                 } else {
 196                         return null;
 197                 }
 198         }
 199
 200         /**
 201          * Create a new Title from an article ID
 202          *
 203          * @param $id Int the page_id corresponding to the Title to create
 204          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 205          * @return Title the new object, or NULL on an error
 206          */
 207         public static function newFromID( $id, $flags = 0 ) {
 208                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 209                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 210                 if ( $row !== false ) {
 211                         $title = Title::newFromRow( $row );
 212                 } else {
 213                         $title = null;
 214                 }
 215                 return $title;
 216         }
 217
 218         /**
 219          * Make an array of titles from an array of IDs
 220          *
 221          * @param $ids Array of Int Array of IDs
 222          * @return Array of Titles
 223          */
 224         public static function newFromIDs( $ids ) {
 225                 if ( !count( $ids ) ) {
 226                         return array();
 227                 }
 228                 $dbr = wfGetDB( DB_SLAVE );
 229
 230                 $res = $dbr->select(
 231                         'page',
 232                         array(
 233                                 'page_namespace', 'page_title', 'page_id',
 234                                 'page_len', 'page_is_redirect', 'page_latest',
 235                         ),
 236                         array( 'page_id' => $ids ),
 237                         __METHOD__
 238                 );
 239
 240                 $titles = array();
 241                 foreach ( $res as $row ) {
 242                         $titles[] = Title::newFromRow( $row );
 243                 }
 244                 return $titles;
 245         }
 246
 247         /**
 248          * Make a Title object from a DB row
 249          *
 250          * @param $row Object database row (needs at least page_title,page_namespace)
 251          * @return Title corresponding Title
 252          */
 253         public static function newFromRow( $row ) {
 254                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 255                 $t->loadFromRow( $row );
 256                 return $t;
 257         }
 258
 259         /**
 260          * Load Title object fields from a DB row.
 261          * If false is given, the title will be treated as non-existing.
 262          *
 263          * @param $row Object|false database row
 264          * @return void
 265          */
 266         public function loadFromRow( $row ) {
 267                 if ( $row ) { // page found
 268                         if ( isset( $row->page_id ) )
 269                                 $this->mArticleID = (int)$row->page_id;
 270                         if ( isset( $row->page_len ) )
 271                                 $this->mLength = (int)$row->page_len;
 272                         if ( isset( $row->page_is_redirect ) )
 273                                 $this->mRedirect = (bool)$row->page_is_redirect;
 274                         if ( isset( $row->page_latest ) )
 275                                 $this->mLatestID = (int)$row->page_latest;
 276                 } else { // page not found
 277                         $this->mArticleID = 0;
 278                         $this->mLength = 0;
 279                         $this->mRedirect = false;
 280                         $this->mLatestID = 0;
 281                 }
 282         }
 283
 284         /**
 285          * Create a new Title from a namespace index and a DB key.
 286          * It's assumed that $ns and $title are *valid*, for instance when
 287          * they came directly from the database or a special page name.
 288          * For convenience, spaces are converted to underscores so that
 289          * eg user_text fields can be used directly.
 290          *
 291          * @param $ns Int the namespace of the article
 292          * @param $title String the unprefixed database key form
 293          * @param $fragment String the link fragment (after the "#")
 294          * @param $interwiki String the interwiki prefix
 295          * @return Title the new object
 296          */
 297         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 298                 $t = new Title();
 299                 $t->mInterwiki = $interwiki;
 300                 $t->mFragment = $fragment;
 301                 $t->mNamespace = $ns = intval( $ns );
 302                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 303                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 304                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 305                 $t->mTextform = str_replace( '_', ' ', $title );
 306                 return $t;
 307         }
 308
 309         /**
 310          * Create a new Title from a namespace index and a DB key.
 311          * The parameters will be checked for validity, which is a bit slower
 312          * than makeTitle() but safer for user-provided data.
 313          *
 314          * @param $ns Int the namespace of the article
 315          * @param $title String database key form
 316          * @param $fragment String the link fragment (after the "#")
 317          * @param $interwiki String interwiki prefix
 318          * @return Title the new object, or NULL on an error
 319          */
 320         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 321                 $t = new Title();
 322                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 323                 if ( $t->secureAndSplit() ) {
 324                         return $t;
 325                 } else {
 326                         return null;
 327                 }
 328         }
 329
 330         /**
 331          * Create a new Title for the Main Page
 332          *
 333          * @return Title the new object
 334          */
 335         public static function newMainPage() {
 336                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 337                 // Don't give fatal errors if the message is broken
 338                 if ( !$title ) {
 339                         $title = Title::newFromText( 'Main Page' );
 340                 }
 341                 return $title;
 342         }
 343
 344         /**
 345          * Extract a redirect destination from a string and return the
 346          * Title, or null if the text doesn't contain a valid redirect
 347          * This will only return the very next target, useful for
 348          * the redirect table and other checks that don't need full recursion
 349          *
 350          * @param $text String: Text with possible redirect
 351          * @return Title: The corresponding Title
 352          */
 353         public static function newFromRedirect( $text ) {
 354                 return self::newFromRedirectInternal( $text );
 355         }
 356
 357         /**
 358          * Extract a redirect destination from a string and return the
 359          * Title, or null if the text doesn't contain a valid redirect
 360          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 361          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 362          *
 363          * @param $text String Text with possible redirect
 364          * @return Title
 365          */
 366         public static function newFromRedirectRecurse( $text ) {
 367                 $titles = self::newFromRedirectArray( $text );
 368                 return $titles ? array_pop( $titles ) : null;
 369         }
 370
 371         /**
 372          * Extract a redirect destination from a string and return an
 373          * array of Titles, or null if the text doesn't contain a valid redirect
 374          * The last element in the array is the final destination after all redirects
 375          * have been resolved (up to $wgMaxRedirects times)
 376          *
 377          * @param $text String Text with possible redirect
 378          * @return Array of Titles, with the destination last
 379          */
 380         public static function newFromRedirectArray( $text ) {
 381                 global $wgMaxRedirects;
 382                 $title = self::newFromRedirectInternal( $text );
 383                 if ( is_null( $title ) ) {
 384                         return null;
 385                 }
 386                 // recursive check to follow double redirects
 387                 $recurse = $wgMaxRedirects;
 388                 $titles = array( $title );
 389                 while ( --$recurse > 0 ) {
 390                         if ( $title->isRedirect() ) {
 391                                 $article = new Article( $title, 0 );
 392                                 $newtitle = $article->getRedirectTarget();
 393                         } else {
 394                                 break;
 395                         }
 396                         // Redirects to some special pages are not permitted
 397                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 398                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 399                                 $title = $newtitle;
 400                                 $titles[] = $newtitle;
 401                         } else {
 402                                 break;
 403                         }
 404                 }
 405                 return $titles;
 406         }
 407
 408         /**
 409          * Really extract the redirect destination
 410          * Do not call this function directly, use one of the newFromRedirect* functions above
 411          *
 412          * @param $text String Text with possible redirect
 413          * @return Title
 414          */
 415         protected static function newFromRedirectInternal( $text ) {
 416                 global $wgMaxRedirects;
 417                 if ( $wgMaxRedirects < 1 ) {
 418                         //redirects are disabled, so quit early
 419                         return null;
 420                 }
 421                 $redir = MagicWord::get( 'redirect' );
 422                 $text = trim( $text );
 423                 if ( $redir->matchStartAndRemove( $text ) ) {
 424                         // Extract the first link and see if it's usable
 425                         // Ensure that it really does come directly after #REDIRECT
 426                         // Some older redirects included a colon, so don't freak about that!
 427                         $m = array();
 428                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 429                                 // Strip preceding colon used to "escape" categories, etc.
 430                                 // and URL-decode links
 431                                 if ( strpos( $m[1], '%' ) !== false ) {
 432                                         // Match behavior of inline link parsing here;
 433                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 434                                 }
 435                                 $title = Title::newFromText( $m[1] );
 436                                 // If the title is a redirect to bad special pages or is invalid, return null
 437                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 438                                         return null;
 439                                 }
 440                                 return $title;
 441                         }
 442                 }
 443                 return null;
 444         }
 445
 446 # ----------------------------------------------------------------------------
 447 #       Static functions
 448 # ----------------------------------------------------------------------------
 449
 450         /**
 451          * Get the prefixed DB key associated with an ID
 452          *
 453          * @param $id Int the page_id of the article
 454          * @return Title an object representing the article, or NULL if no such article was found
 455          */
 456         public static function nameOf( $id ) {
 457                 $dbr = wfGetDB( DB_SLAVE );
 458
 459                 $s = $dbr->selectRow(
 460                         'page',
 461                         array( 'page_namespace', 'page_title' ),
 462                         array( 'page_id' => $id ),
 463                         __METHOD__
 464                 );
 465                 if ( $s === false ) {
 466                         return null;
 467                 }
 468
 469                 $n = self::makeName( $s->page_namespace, $s->page_title );
 470                 return $n;
 471         }
 472
 473         /**
 474          * Get a regex character class describing the legal characters in a link
 475          *
 476          * @return String the list of characters, not delimited
 477          */
 478         public static function legalChars() {
 479                 global $wgLegalTitleChars;
 480                 return $wgLegalTitleChars;
 481         }
 482
 483         /**
 484          * Get a string representation of a title suitable for
 485          * including in a search index
 486          *
 487          * @param $ns Int a namespace index
 488          * @param $title String text-form main part
 489          * @return String a stripped-down title string ready for the search index
 490          */
 491         public static function indexTitle( $ns, $title ) {
 492                 global $wgContLang;
 493
 494                 $lc = SearchEngine::legalSearchChars() . '&#;';
 495                 $t = $wgContLang->normalizeForSearch( $title );
 496                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 497                 $t = $wgContLang->lc( $t );
 498
 499                 # Handle 's, s'
 500                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 501                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 502
 503                 $t = preg_replace( "/\\s+/", ' ', $t );
 504
 505                 if ( $ns == NS_FILE ) {
 506                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 507                 }
 508                 return trim( $t );
 509         }
 510
 511         /**
 512          * Make a prefixed DB key from a DB key and a namespace index
 513          *
 514          * @param $ns Int numerical representation of the namespace
 515          * @param $title String the DB key form the title
 516          * @param $fragment String The link fragment (after the "#")
 517          * @param $interwiki String The interwiki prefix
 518          * @return String the prefixed form of the title
 519          */
 520         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 521                 global $wgContLang;
 522
 523                 $namespace = $wgContLang->getNsText( $ns );
 524                 $name = $namespace == '' ? $title : "$namespace:$title";
 525                 if ( strval( $interwiki ) != '' ) {
 526                         $name = "$interwiki:$name";
 527                 }
 528                 if ( strval( $fragment ) != '' ) {
 529                         $name .= '#' . $fragment;
 530                 }
 531                 return $name;
 532         }
 533
 534         /**
 535          * Determine whether the object refers to a page within
 536          * this project.
 537          *
 538          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 539          */
 540         public function isLocal() {
 541                 if ( $this->mInterwiki != '' ) {
 542                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 543                 } else {
 544                         return true;
 545                 }
 546         }
 547
 548         /**
 549          * Determine whether the object refers to a page within
 550          * this project and is transcludable.
 551          *
 552          * @return Bool TRUE if this is transcludable
 553          */
 554         public function isTrans() {
 555                 if ( $this->mInterwiki == '' ) {
 556                         return false;
 557                 }
 558
 559                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 560         }
 561
 562         /**
 563          * Returns the DB name of the distant wiki which owns the object.
 564          *
 565          * @return String the DB name
 566          */
 567         public function getTransWikiID() {
 568                 if ( $this->mInterwiki == '' ) {
 569                         return false;
 570                 }
 571
 572                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 573         }
 574
 575         /**
 576          * Escape a text fragment, say from a link, for a URL
 577          *
 578          * @param $fragment string containing a URL or link fragment (after the "#")
 579          * @return String: escaped string
 580          */
 581         static function escapeFragmentForURL( $fragment ) {
 582                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 583                 # fragments appear not to work in IE (at least up to 7) or in at least
 584                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 585                 # to care if they aren't encoded.
 586                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 587         }
 588
 589 # ----------------------------------------------------------------------------
 590 #       Other stuff
 591 # ----------------------------------------------------------------------------
 592
 593         /** Simple accessors */
 594         /**
 595          * Get the text form (spaces not underscores) of the main part
 596          *
 597          * @return String Main part of the title
 598          */
 599         public function getText() { return $this->mTextform; }
 600
 601         /**
 602          * Get the URL-encoded form of the main part
 603          *
 604          * @return String Main part of the title, URL-encoded
 605          */
 606         public function getPartialURL() { return $this->mUrlform; }
 607
 608         /**
 609          * Get the main part with underscores
 610          *
 611          * @return String: Main part of the title, with underscores
 612          */
 613         public function getDBkey() { return $this->mDbkeyform; }
 614
 615         /**
 616          * Get the namespace index, i.e. one of the NS_xxxx constants.
 617          *
 618          * @return Integer: Namespace index
 619          */
 620         public function getNamespace() { return $this->mNamespace; }
 621
 622         /**
 623          * Get the namespace text
 624          *
 625          * @return String: Namespace text
 626          */
 627         public function getNsText() {
 628                 global $wgContLang;
 629
 630                 if ( $this->mInterwiki != '' ) {
 631                         // This probably shouldn't even happen. ohh man, oh yuck.
 632                         // But for interwiki transclusion it sometimes does.
 633                         // Shit. Shit shit shit.
 634                         //
 635                         // Use the canonical namespaces if possible to try to
 636                         // resolve a foreign namespace.
 637                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 638                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 639                         }
 640                 }
 641
 642                 if ( $wgContLang->needsGenderDistinction() &&
 643                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 644                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 645                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 646                 }
 647
 648                 return $wgContLang->getNsText( $this->mNamespace );
 649         }
 650
 651         /**
 652          * Get the DB key with the initial letter case as specified by the user
 653          *
 654          * @return String DB key
 655          */
 656         function getUserCaseDBKey() {
 657                 return $this->mUserCaseDBKey;
 658         }
 659
 660         /**
 661          * Get the namespace text of the subject (rather than talk) page
 662          *
 663          * @return String Namespace text
 664          */
 665         public function getSubjectNsText() {
 666                 global $wgContLang;
 667                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 668         }
 669
 670         /**
 671          * Get the namespace text of the talk page
 672          *
 673          * @return String Namespace text
 674          */
 675         public function getTalkNsText() {
 676                 global $wgContLang;
 677                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 678         }
 679
 680         /**
 681          * Could this title have a corresponding talk page?
 682          *
 683          * @return Bool TRUE or FALSE
 684          */
 685         public function canTalk() {
 686                 return( MWNamespace::canTalk( $this->mNamespace ) );
 687         }
 688
 689         /**
 690          * Get the interwiki prefix (or null string)
 691          *
 692          * @return String Interwiki prefix
 693          */
 694         public function getInterwiki() { return $this->mInterwiki; }
 695
 696         /**
 697          * Get the Title fragment (i.e.\ the bit after the #) in text form
 698          *
 699          * @return String Title fragment
 700          */
 701         public function getFragment() { return $this->mFragment; }
 702
 703         /**
 704          * Get the fragment in URL form, including the "#" character if there is one
 705          * @return String Fragment in URL form
 706          */
 707         public function getFragmentForURL() {
 708                 if ( $this->mFragment == '' ) {
 709                         return '';
 710                 } else {
 711                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 712                 }
 713         }
 714
 715         /**
 716          * Get the default namespace index, for when there is no namespace
 717          *
 718          * @return Int Default namespace index
 719          */
 720         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 721
 722         /**
 723          * Get title for search index
 724          *
 725          * @return String a stripped-down title string ready for the
 726          *  search index
 727          */
 728         public function getIndexTitle() {
 729                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 730         }
 731
 732         /**
 733          * Get the prefixed database key form
 734          *
 735          * @return String the prefixed title, with underscores and
 736          *  any interwiki and namespace prefixes
 737          */
 738         public function getPrefixedDBkey() {
 739                 $s = $this->prefix( $this->mDbkeyform );
 740                 $s = str_replace( ' ', '_', $s );
 741                 return $s;
 742         }
 743
 744         /**
 745          * Get the prefixed title with spaces.
 746          * This is the form usually used for display
 747          *
 748          * @return String the prefixed title, with spaces
 749          */
 750         public function getPrefixedText() {
 751                 // @todo FIXME: Bad usage of empty() ?
 752                 if ( empty( $this->mPrefixedText ) ) {
 753                         $s = $this->prefix( $this->mTextform );
 754                         $s = str_replace( '_', ' ', $s );
 755                         $this->mPrefixedText = $s;
 756                 }
 757                 return $this->mPrefixedText;
 758         }
 759
 760         /**
 761          * Return the prefixed title with spaces _without_ the interwiki prefix
 762          *
 763          * @return \type{\string} the title, prefixed by the namespace but not by the interwiki prefix, with spaces
 764          */
 765         public function getSemiPrefixedText() {
 766                 if ( !isset( $this->mSemiPrefixedText ) ){
 767                         $s = ( $this->mNamespace === NS_MAIN ? '' : $this->getNsText() . ':' ) . $this->mTextform;
 768                         $s = str_replace( '_', ' ', $s );
 769                         $this->mSemiPrefixedText = $s;
 770                 }
 771                 return $this->mSemiPrefixedText;
 772         }
 773
 774         /**
 775          * Get the prefixed title with spaces, plus any fragment
 776          * (part beginning with '#')
 777          *
 778          * @return String the prefixed title, with spaces and the fragment, including '#'
 779          */
 780         public function getFullText() {
 781                 $text = $this->getPrefixedText();
 782                 if ( $this->mFragment != '' ) {
 783                         $text .= '#' . $this->mFragment;
 784                 }
 785                 return $text;
 786         }
 787
 788         /**
 789          * Get the base page name, i.e. the leftmost part before any slashes
 790          *
 791          * @return String Base name
 792          */
 793         public function getBaseText() {
 794                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 795                         return $this->getText();
 796                 }
 797
 798                 $parts = explode( '/', $this->getText() );
 799                 # Don't discard the real title if there's no subpage involved
 800                 if ( count( $parts ) > 1 ) {
 801                         unset( $parts[count( $parts ) - 1] );
 802                 }
 803                 return implode( '/', $parts );
 804         }
 805
 806         /**
 807          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
 808          *
 809          * @return String Subpage name
 810          */
 811         public function getSubpageText() {
 812                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 813                         return( $this->mTextform );
 814                 }
 815                 $parts = explode( '/', $this->mTextform );
 816                 return( $parts[count( $parts ) - 1] );
 817         }
 818
 819         /**
 820          * Get a URL-encoded form of the subpage text
 821          *
 822          * @return String URL-encoded subpage name
 823          */
 824         public function getSubpageUrlForm() {
 825                 $text = $this->getSubpageText();
 826                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 827                 return( $text );
 828         }
 829
 830         /**
 831          * Get a URL-encoded title (not an actual URL) including interwiki
 832          *
 833          * @return String the URL-encoded form
 834          */
 835         public function getPrefixedURL() {
 836                 $s = $this->prefix( $this->mDbkeyform );
 837                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 838                 return $s;
 839         }
 840
 841         /**
 842          * Get a real URL referring to this title, with interwiki link and
 843          * fragment
 844          *
 845          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 846          *   links. Can be specified as an associative array as well, e.g.,
 847          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 848          * @param $variant String language variant of url (for sr, zh..)
 849          * @return String the URL
 850          */
 851         public function getFullURL( $query = '', $variant = false ) {
 852                 # Hand off all the decisions on urls to getLocalURL
 853                 $url = $this->getLocalURL( $query, $variant );
 854
 855                 # Expand the url to make it a full url. Note that getLocalURL has the
 856                 # potential to output full urls for a variety of reasons, so we use
 857                 # wfExpandUrl instead of simply prepending $wgServer
 858                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
 859
 860                 # Finally, add the fragment.
 861                 $url .= $this->getFragmentForURL();
 862
 863                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 864                 return $url;
 865         }
 866
 867         /**
 868          * Get a URL with no fragment or server name.  If this page is generated
 869          * with action=render, $wgServer is prepended.
 870          *
 871          * @param $query Mixed: an optional query string; if not specified,
 872          *   $wgArticlePath will be used.  Can be specified as an associative array
 873          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 874          *   URL-escaped).
 875          * @param $variant String language variant of url (for sr, zh..)
 876          * @return String the URL
 877          */
 878         public function getLocalURL( $query = '', $variant = false ) {
 879                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 880                 global $wgVariantArticlePath, $wgContLang;
 881
 882                 if ( is_array( $query ) ) {
 883                         $query = wfArrayToCGI( $query );
 884                 }
 885
 886                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 887                 if ( $interwiki ) {
 888                         $namespace = $this->getNsText();
 889                         if ( $namespace != '' ) {
 890                                 # Can this actually happen? Interwikis shouldn't be parsed.
 891                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 892                                 $namespace .= ':';
 893                         }
 894                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 895                         $url = wfAppendQuery( $url, $query );
 896                 } else {
 897                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 898                         if ( $query == '' ) {
 899                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 900                                         if ( !$wgVariantArticlePath ) {
 901                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 902                                         } else {
 903                                                 $variantArticlePath = $wgVariantArticlePath;
 904                                         }
 905                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 906                                         $url = str_replace( '$1', $dbkey, $url  );
 907                                 } else {
 908                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 909                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
 910                                 }
 911                         } else {
 912                                 global $wgActionPaths;
 913                                 $url = false;
 914                                 $matches = array();
 915                                 if ( !empty( $wgActionPaths ) &&
 916                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 917                                 {
 918                                         $action = urldecode( $matches[2] );
 919                                         if ( isset( $wgActionPaths[$action] ) ) {
 920                                                 $query = $matches[1];
 921                                                 if ( isset( $matches[4] ) ) {
 922                                                         $query .= $matches[4];
 923                                                 }
 924                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 925                                                 if ( $query != '' ) {
 926                                                         $url = wfAppendQuery( $url, $query );
 927                                                 }
 928                                         }
 929                                 }
 930
 931                                 if ( $url === false ) {
 932                                         if ( $query == '-' ) {
 933                                                 $query = '';
 934                                         }
 935                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 936                                 }
 937                         }
 938
 939                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
 940
 941                         // @todo FIXME: This causes breakage in various places when we
 942                         // actually expected a local URL and end up with dupe prefixes.
 943                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 944                                 $url = $wgServer . $url;
 945                         }
 946                 }
 947                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
 948                 return $url;
 949         }
 950
 951         /**
 952          * Get a URL that's the simplest URL that will be valid to link, locally,
 953          * to the current Title.  It includes the fragment, but does not include
 954          * the server unless action=render is used (or the link is external).  If
 955          * there's a fragment but the prefixed text is empty, we just return a link
 956          * to the fragment.
 957          *
 958          * The result obviously should not be URL-escaped, but does need to be
 959          * HTML-escaped if it's being output in HTML.
 960          *
 961          * @param $query Array of Strings An associative array of key => value pairs for the
 962          *   query string.  Keys and values will be escaped.
 963          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 964          *   for external links.  Default is "false" (same variant as current page,
 965          *   for anonymous users).
 966          * @return String the URL
 967          */
 968         public function getLinkUrl( $query = array(), $variant = false ) {
 969                 wfProfileIn( __METHOD__ );
 970                 if ( $this->isExternal() ) {
 971                         $ret = $this->getFullURL( $query );
 972                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 973                         $ret = $this->getFragmentForURL();
 974                 } else {
 975                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 976                 }
 977                 wfProfileOut( __METHOD__ );
 978                 return $ret;
 979         }
 980
 981         /**
 982          * Get an HTML-escaped version of the URL form, suitable for
 983          * using in a link, without a server name or fragment
 984          *
 985          * @param $query String an optional query string
 986          * @return String the URL
 987          */
 988         public function escapeLocalURL( $query = '' ) {
 989                 return htmlspecialchars( $this->getLocalURL( $query ) );
 990         }
 991
 992         /**
 993          * Get an HTML-escaped version of the URL form, suitable for
 994          * using in a link, including the server name and fragment
 995          *
 996          * @param $query String an optional query string
 997          * @return String the URL
 998          */
 999         public function escapeFullURL( $query = '' ) {
1000                 return htmlspecialchars( $this->getFullURL( $query ) );
1001         }
1002
1003         /**
1004          * HTML-escaped version of getCanonicalURL()
1005          */
1006         public function escapeCanonicalURL( $query = '', $variant = false ) {
1007                 return htmlspecialchars( $this->getCanonicalURL( $query, $variant ) );
1008         }
1009
1010         /**
1011          * Get the URL form for an internal link.
1012          * - Used in various Squid-related code, in case we have a different
1013          * internal hostname for the server from the exposed one.
1014          *
1015          * This uses $wgInternalServer to qualify the path, or $wgServer
1016          * if $wgInternalServer is not set. If the server variable used is
1017          * protocol-relative, the URL will be expanded to http://
1018          *
1019          * @param $query String an optional query string
1020          * @param $variant String language variant of url (for sr, zh..)
1021          * @return String the URL
1022          */
1023         public function getInternalURL( $query = '', $variant = false ) {
1024                 if ( $this->isExternal( ) ) {
1025                         $server = '';
1026                 } else {
1027                         global $wgInternalServer, $wgServer;
1028                         $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1029                 }
1030                 $url = wfExpandUrl( $server . $this->getLocalURL( $query, $variant ), PROTO_HTTP );
1031                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1032                 return $url;
1033         }
1034
1035         /**
1036          * Get the URL for a canonical link, for use in things like IRC and
1037          * e-mail notifications. Uses $wgCanonicalServer and the
1038          * GetCanonicalURL hook.
1039          *
1040          * @param $query string An optional query string
1041          * @param $variant string Language variant of URL (for sr, zh, ...)
1042          * @return string The URL
1043          */
1044         public function getCanonicalURL( $query = '', $variant = false ) {
1045                 global $wgCanonicalServer;
1046                 $url = $wgCanonicalServer . $this->getLocalURL( $query, $variant );
1047                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1048                 return $url;
1049         }
1050
1051         /**
1052          * Get the edit URL for this Title
1053          *
1054          * @return String the URL, or a null string if this is an
1055          *  interwiki link
1056          */
1057         public function getEditURL() {
1058                 if ( $this->mInterwiki != '' ) {
1059                         return '';
1060                 }
1061                 $s = $this->getLocalURL( 'action=edit' );
1062
1063                 return $s;
1064         }
1065
1066         /**
1067          * Get the HTML-escaped displayable text form.
1068          * Used for the title field in <a> tags.
1069          *
1070          * @return String the text, including any prefixes
1071          */
1072         public function getEscapedText() {
1073                 return htmlspecialchars( $this->getPrefixedText() );
1074         }
1075
1076         /**
1077          * Is this Title interwiki?
1078          *
1079          * @return Bool
1080          */
1081         public function isExternal() {
1082                 return ( $this->mInterwiki != '' );
1083         }
1084
1085         /**
1086          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1087          *
1088          * @param $action String Action to check (default: edit)
1089          * @return Bool
1090          */
1091         public function isSemiProtected( $action = 'edit' ) {
1092                 if ( $this->exists() ) {
1093                         $restrictions = $this->getRestrictions( $action );
1094                         if ( count( $restrictions ) > 0 ) {
1095                                 foreach ( $restrictions as $restriction ) {
1096                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1097                                                 return false;
1098                                         }
1099                                 }
1100                         } else {
1101                                 # Not protected
1102                                 return false;
1103                         }
1104                         return true;
1105                 } else {
1106                         # If it doesn't exist, it can't be protected
1107                         return false;
1108                 }
1109         }
1110
1111         /**
1112          * Does the title correspond to a protected article?
1113          *
1114          * @param $action String the action the page is protected from,
1115          * by default checks all actions.
1116          * @return Bool
1117          */
1118         public function isProtected( $action = '' ) {
1119                 global $wgRestrictionLevels;
1120
1121                 $restrictionTypes = $this->getRestrictionTypes();
1122
1123                 # Special pages have inherent protection
1124                 if( $this->getNamespace() == NS_SPECIAL ) {
1125                         return true;
1126                 }
1127
1128                 # Check regular protection levels
1129                 foreach ( $restrictionTypes as $type ) {
1130                         if ( $action == $type || $action == '' ) {
1131                                 $r = $this->getRestrictions( $type );
1132                                 foreach ( $wgRestrictionLevels as $level ) {
1133                                         if ( in_array( $level, $r ) && $level != '' ) {
1134                                                 return true;
1135                                         }
1136                                 }
1137                         }
1138                 }
1139
1140                 return false;
1141         }
1142
1143         /**
1144          * Is this a conversion table for the LanguageConverter?
1145          *
1146          * @return Bool
1147          */
1148         public function isConversionTable() {
1149                 if(
1150                         $this->getNamespace() == NS_MEDIAWIKI &&
1151                         strpos( $this->getText(), 'Conversiontable' ) !== false
1152                 )
1153                 {
1154                         return true;
1155                 }
1156
1157                 return false;
1158         }
1159
1160         /**
1161          * Is $wgUser watching this page?
1162          *
1163          * @return Bool
1164          */
1165         public function userIsWatching() {
1166                 global $wgUser;
1167
1168                 if ( is_null( $this->mWatched ) ) {
1169                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1170                                 $this->mWatched = false;
1171                         } else {
1172                                 $this->mWatched = $wgUser->isWatched( $this );
1173                         }
1174                 }
1175                 return $this->mWatched;
1176         }
1177
1178         /**
1179          * Can $wgUser perform $action on this page?
1180          * This skips potentially expensive cascading permission checks
1181          * as well as avoids expensive error formatting
1182          *
1183          * Suitable for use for nonessential UI controls in common cases, but
1184          * _not_ for functional access control.
1185          *
1186          * May provide false positives, but should never provide a false negative.
1187          *
1188          * @param $action String action that permission needs to be checked for
1189          * @return Bool
1190          */
1191         public function quickUserCan( $action ) {
1192                 return $this->userCan( $action, false );
1193         }
1194
1195         /**
1196          * Determines if $user is unable to edit this page because it has been protected
1197          * by $wgNamespaceProtection.
1198          *
1199          * @param $user User object to check permissions
1200          * @return Bool
1201          */
1202         public function isNamespaceProtected( User $user ) {
1203                 global $wgNamespaceProtection;
1204
1205                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1206                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1207                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1208                                         return true;
1209                                 }
1210                         }
1211                 }
1212                 return false;
1213         }
1214
1215         /**
1216          * Can $wgUser perform $action on this page?
1217          *
1218          * @param $action String action that permission needs to be checked for
1219          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1220          * @return Bool
1221          */
1222         public function userCan( $action, $doExpensiveQueries = true ) {
1223                 global $wgUser;
1224                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1225         }
1226
1227         /**
1228          * Can $user perform $action on this page?
1229          *
1230          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1231          *
1232          * @param $action String action that permission needs to be checked for
1233          * @param $user User to check
1234          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1235          *   skipping checks for cascading protections and user blocks.
1236          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1237          * @return Array of arguments to wfMsg to explain permissions problems.
1238          */
1239         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1240                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1241
1242                 // Remove the errors being ignored.
1243                 foreach ( $errors as $index => $error ) {
1244                         $error_key = is_array( $error ) ? $error[0] : $error;
1245
1246                         if ( in_array( $error_key, $ignoreErrors ) ) {
1247                                 unset( $errors[$index] );
1248                         }
1249                 }
1250
1251                 return $errors;
1252         }
1253
1254         /**
1255          * Permissions checks that fail most often, and which are easiest to test.
1256          *
1257          * @param $action String the action to check
1258          * @param $user User user to check
1259          * @param $errors Array list of current errors
1260          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1261          * @param $short Boolean short circuit on first error
1262          *
1263          * @return Array list of errors
1264          */
1265         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1266                 $ns = $this->getNamespace();
1267
1268                 if ( $action == 'create' ) {
1269                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1270                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1271                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1272                         }
1273                 } elseif ( $action == 'move' ) {
1274                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1275                                         && $ns == NS_USER && !$this->isSubpage() ) {
1276                                 // Show user page-specific message only if the user can move other pages
1277                                 $errors[] = array( 'cant-move-user-page' );
1278                         }
1279
1280                         // Check if user is allowed to move files if it's a file
1281                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1282                                 $errors[] = array( 'movenotallowedfile' );
1283                         }
1284
1285                         if ( !$user->isAllowed( 'move', $ns) ) {
1286                                 // User can't move anything
1287
1288                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1289                                         array( 'user' ), $ns ), true );
1290                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1291                                         array( 'autoconfirmed' ), $ns ), true );
1292
1293                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1294                                         // custom message if logged-in users without any special rights can move
1295                                         $errors[] = array( 'movenologintext' );
1296                                 } else {
1297                                         $errors[] = array( 'movenotallowed' );
1298                                 }
1299                         }
1300                 } elseif ( $action == 'move-target' ) {
1301                         if ( !$user->isAllowed( 'move', $ns ) ) {
1302                                 // User can't move anything
1303                                 $errors[] = array( 'movenotallowed' );
1304                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1305                                         && $ns == NS_USER && !$this->isSubpage() ) {
1306                                 // Show user page-specific message only if the user can move other pages
1307                                 $errors[] = array( 'cant-move-to-user-page' );
1308                         }
1309                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1310                         // We avoid expensive display logic for quickUserCan's and such
1311                         $groups = false;
1312                         if ( !$short ) {
1313                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1314                                         User::getGroupsWithPermission( $action, $ns ) );
1315                         }
1316
1317                         if ( $groups ) {
1318                                 global $wgLang;
1319                                 $return = array(
1320                                         'badaccess-groups',
1321                                         $wgLang->commaList( $groups ),
1322                                         count( $groups )
1323                                 );
1324                         } else {
1325                                 $return = array( 'badaccess-group0' );
1326                         }
1327                         $errors[] = $return;
1328                 }
1329
1330                 return $errors;
1331         }
1332
1333         /**
1334          * Add the resulting error code to the errors array
1335          *
1336          * @param $errors Array list of current errors
1337          * @param $result Mixed result of errors
1338          *
1339          * @return Array list of errors
1340          */
1341         private function resultToError( $errors, $result ) {
1342                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1343                         // A single array representing an error
1344                         $errors[] = $result;
1345                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1346                         // A nested array representing multiple errors
1347                         $errors = array_merge( $errors, $result );
1348                 } elseif ( $result !== '' && is_string( $result ) ) {
1349                         // A string representing a message-id
1350                         $errors[] = array( $result );
1351                 } elseif ( $result === false ) {
1352                         // a generic "We don't want them to do that"
1353                         $errors[] = array( 'badaccess-group0' );
1354                 }
1355                 return $errors;
1356         }
1357
1358         /**
1359          * Check various permission hooks
1360          *
1361          * @param $action String the action to check
1362          * @param $user User user to check
1363          * @param $errors Array list of current errors
1364          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1365          * @param $short Boolean short circuit on first error
1366          *
1367          * @return Array list of errors
1368          */
1369         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1370                 // Use getUserPermissionsErrors instead
1371                 $result = '';
1372                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1373                         return $result ? array() : array( array( 'badaccess-group0' ) );
1374                 }
1375                 // Check getUserPermissionsErrors hook
1376                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1377                         $errors = $this->resultToError( $errors, $result );
1378                 }
1379                 // Check getUserPermissionsErrorsExpensive hook
1380                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1381                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1382                         $errors = $this->resultToError( $errors, $result );
1383                 }
1384
1385                 return $errors;
1386         }
1387
1388         /**
1389          * Check permissions on special pages & namespaces
1390          *
1391          * @param $action String the action to check
1392          * @param $user User user to check
1393          * @param $errors Array list of current errors
1394          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1395          * @param $short Boolean short circuit on first error
1396          *
1397          * @return Array list of errors
1398          */
1399         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1400                 # Only 'createaccount' and 'execute' can be performed on
1401                 # special pages, which don't actually exist in the DB.
1402                 $specialOKActions = array( 'createaccount', 'execute' );
1403                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1404                         $errors[] = array( 'ns-specialprotected' );
1405                 }
1406
1407                 # Check $wgNamespaceProtection for restricted namespaces
1408                 if ( $this->isNamespaceProtected( $user ) ) {
1409                         $ns = $this->mNamespace == NS_MAIN ?
1410                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1411                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1412                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1413                 }
1414
1415                 return $errors;
1416         }
1417
1418         /**
1419          * Check CSS/JS sub-page permissions
1420          *
1421          * @param $action String the action to check
1422          * @param $user User user to check
1423          * @param $errors Array list of current errors
1424          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1425          * @param $short Boolean short circuit on first error
1426          *
1427          * @return Array list of errors
1428          */
1429         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1430                 # Protect css/js subpages of user pages
1431                 # XXX: this might be better using restrictions
1432                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1433                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1434                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1435                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1436                                 $errors[] = array( 'customcssprotected' );
1437                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1438                                 $errors[] = array( 'customjsprotected' );
1439                         }
1440                 }
1441
1442                 return $errors;
1443         }
1444
1445         /**
1446          * Check against page_restrictions table requirements on this
1447          * page. The user must possess all required rights for this
1448          * action.
1449          *
1450          * @param $action String the action to check
1451          * @param $user User user to check
1452          * @param $errors Array list of current errors
1453          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1454          * @param $short Boolean short circuit on first error
1455          *
1456          * @return Array list of errors
1457          */
1458         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1459                 foreach ( $this->getRestrictions( $action ) as $right ) {
1460                         // Backwards compatibility, rewrite sysop -> protect
1461                         if ( $right == 'sysop' ) {
1462                                 $right = 'protect';
1463                         }
1464                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1465                                 // Users with 'editprotected' permission can edit protected pages
1466                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected', $this->mNamespace ) ) {
1467                                         // Users with 'editprotected' permission cannot edit protected pages
1468                                         // with cascading option turned on.
1469                                         if ( $this->mCascadeRestriction ) {
1470                                                 $errors[] = array( 'protectedpagetext', $right );
1471                                         }
1472                                 } else {
1473                                         $errors[] = array( 'protectedpagetext', $right );
1474                                 }
1475                         }
1476                 }
1477
1478                 return $errors;
1479         }
1480
1481         /**
1482          * Check restrictions on cascading pages.
1483          *
1484          * @param $action String the action to check
1485          * @param $user User to check
1486          * @param $errors Array list of current errors
1487          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1488          * @param $short Boolean short circuit on first error
1489          *
1490          * @return Array list of errors
1491          */
1492         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1493                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1494                         # We /could/ use the protection level on the source page, but it's
1495                         # fairly ugly as we have to establish a precedence hierarchy for pages
1496                         # included by multiple cascade-protected pages. So just restrict
1497                         # it to people with 'protect' permission, as they could remove the
1498                         # protection anyway.
1499                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1500                         # Cascading protection depends on more than this page...
1501                         # Several cascading protected pages may include this page...
1502                         # Check each cascading level
1503                         # This is only for protection restrictions, not for all actions
1504                         if ( isset( $restrictions[$action] ) ) {
1505                                 foreach ( $restrictions[$action] as $right ) {
1506                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1507                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1508                                                 $pages = '';
1509                                                 foreach ( $cascadingSources as $page )
1510                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1511                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1512                                         }
1513                                 }
1514                         }
1515                 }
1516
1517                 return $errors;
1518         }
1519
1520         /**
1521          * Check action permissions not already checked in checkQuickPermissions
1522          *
1523          * @param $action String the action to check
1524          * @param $user User to check
1525          * @param $errors Array list of current errors
1526          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1527          * @param $short Boolean short circuit on first error
1528          *
1529          * @return Array list of errors
1530          */
1531         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1532                 if ( $action == 'protect' ) {
1533                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1534                                 // If they can't edit, they shouldn't protect.
1535                                 $errors[] = array( 'protect-cantedit' );
1536                         }
1537                 } elseif ( $action == 'create' ) {
1538                         $title_protection = $this->getTitleProtection();
1539                         if( $title_protection ) {
1540                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1541                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1542                                 }
1543                                 if( $title_protection['pt_create_perm'] == '' ||
1544                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1545                                                 $this->mNamespace ) ) {
1546                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1547                                 }
1548                         }
1549                 } elseif ( $action == 'move' ) {
1550                         // Check for immobile pages
1551                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1552                                 // Specific message for this case
1553                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1554                         } elseif ( !$this->isMovable() ) {
1555                                 // Less specific message for rarer cases
1556                                 $errors[] = array( 'immobile-page' );
1557                         }
1558                 } elseif ( $action == 'move-target' ) {
1559                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1560                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1561                         } elseif ( !$this->isMovable() ) {
1562                                 $errors[] = array( 'immobile-target-page' );
1563                         }
1564                 }
1565                 return $errors;
1566         }
1567
1568         /**
1569          * Check that the user isn't blocked from editting.
1570          *
1571          * @param $action String the action to check
1572          * @param $user User to check
1573          * @param $errors Array list of current errors
1574          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1575          * @param $short Boolean short circuit on first error
1576          *
1577          * @return Array list of errors
1578          */
1579         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1580                 if( !$doExpensiveQueries ) {
1581                         return $errors;
1582                 }
1583
1584                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1585
1586                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1587                         $errors[] = array( 'confirmedittext' );
1588                 }
1589
1590                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1591                         // Edit blocks should not affect reading.
1592                         // Account creation blocks handled at userlogin.
1593                         // Unblocking handled in SpecialUnblock
1594                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1595                         // Don't block the user from editing their own talk page unless they've been
1596                         // explicitly blocked from that too.
1597                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1598                         $block = $user->mBlock;
1599
1600                         // This is from OutputPage::blockedPage
1601                         // Copied at r23888 by werdna
1602
1603                         $id = $user->blockedBy();
1604                         $reason = $user->blockedFor();
1605                         if ( $reason == '' ) {
1606                                 $reason = wfMsg( 'blockednoreason' );
1607                         }
1608                         $ip = $user->getRequest()->getIP();
1609
1610                         if ( is_numeric( $id ) ) {
1611                                 $name = User::whoIs( $id );
1612                         } else {
1613                                 $name = $id;
1614                         }
1615
1616                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1617                         $blockid = $block->getId();
1618                         $blockExpiry = $user->mBlock->mExpiry;
1619                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1620                         if ( $blockExpiry == 'infinity' ) {
1621                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1622                         } else {
1623                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1624                         }
1625
1626                         $intended = strval( $user->mBlock->getTarget() );
1627
1628                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1629                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1630                 }
1631
1632                 return $errors;
1633         }
1634
1635         /**
1636          * Can $user perform $action on this page? This is an internal function,
1637          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1638          * checks on wfReadOnly() and blocks)
1639          *
1640          * @param $action String action that permission needs to be checked for
1641          * @param $user User to check
1642          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1643          * @param $short Bool Set this to true to stop after the first permission error.
1644          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1645          */
1646         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1647                 wfProfileIn( __METHOD__ );
1648
1649                 $errors = array();
1650                 $checks = array(
1651                         'checkQuickPermissions',
1652                         'checkPermissionHooks',
1653                         'checkSpecialsAndNSPermissions',
1654                         'checkCSSandJSPermissions',
1655                         'checkPageRestrictions',
1656                         'checkCascadingSourcesRestrictions',
1657                         'checkActionPermissions',
1658                         'checkUserBlock'
1659                 );
1660
1661                 while( count( $checks ) > 0 &&
1662                            !( $short && count( $errors ) > 0 ) ) {
1663                         $method = array_shift( $checks );
1664                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1665                 }
1666
1667                 wfProfileOut( __METHOD__ );
1668                 return $errors;
1669         }
1670
1671         /**
1672          * Is this title subject to title protection?
1673          * Title protection is the one applied against creation of such title.
1674          *
1675          * @return Mixed An associative array representing any existent title
1676          *   protection, or false if there's none.
1677          */
1678         private function getTitleProtection() {
1679                 // Can't protect pages in special namespaces
1680                 if ( $this->getNamespace() < 0 ) {
1681                         return false;
1682                 }
1683
1684                 // Can't protect pages that exist.
1685                 if ( $this->exists() ) {
1686                         return false;
1687                 }
1688
1689                 if ( !isset( $this->mTitleProtection ) ) {
1690                         $dbr = wfGetDB( DB_SLAVE );
1691                         $res = $dbr->select( 'protected_titles', '*',
1692                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1693                                 __METHOD__ );
1694
1695                         // fetchRow returns false if there are no rows.
1696                         $this->mTitleProtection = $dbr->fetchRow( $res );
1697                 }
1698                 return $this->mTitleProtection;
1699         }
1700
1701         /**
1702          * Update the title protection status
1703          *
1704          * @param $create_perm String Permission required for creation
1705          * @param $reason String Reason for protection
1706          * @param $expiry String Expiry timestamp
1707          * @return boolean true
1708          */
1709         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1710                 global $wgUser, $wgContLang;
1711
1712                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1713                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1714                         // No change
1715                         return true;
1716                 }
1717
1718                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1719
1720                 $dbw = wfGetDB( DB_MASTER );
1721
1722                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1723
1724                 $expiry_description = '';
1725                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1726                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1727                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1728                 } else {
1729                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1730                 }
1731
1732                 # Update protection table
1733                 if ( $create_perm != '' ) {
1734                         $this->mTitleProtection = array(
1735                                         'pt_namespace' => $namespace,
1736                                         'pt_title' => $title,
1737                                         'pt_create_perm' => $create_perm,
1738                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1739                                         'pt_expiry' => $encodedExpiry,
1740                                         'pt_user' => $wgUser->getId(),
1741                                         'pt_reason' => $reason,
1742                                 );
1743                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1744                                 $this->mTitleProtection, __METHOD__     );
1745                 } else {
1746                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1747                                 'pt_title' => $title ), __METHOD__ );
1748                         $this->mTitleProtection = false;
1749                 }
1750
1751                 # Update the protection log
1752                 if ( $dbw->affectedRows() ) {
1753                         $log = new LogPage( 'protect' );
1754
1755                         if ( $create_perm ) {
1756                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1757                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1758                         } else {
1759                                 $log->addEntry( 'unprotect', $this, $reason );
1760                         }
1761                 }
1762
1763                 return true;
1764         }
1765
1766         /**
1767          * Remove any title protection due to page existing
1768          */
1769         public function deleteTitleProtection() {
1770                 $dbw = wfGetDB( DB_MASTER );
1771
1772                 $dbw->delete(
1773                         'protected_titles',
1774                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1775                         __METHOD__
1776                 );
1777                 $this->mTitleProtection = false;
1778         }
1779
1780         /**
1781          * Would anybody with sufficient privileges be able to move this page?
1782          * Some pages just aren't movable.
1783          *
1784          * @return Bool TRUE or FALSE
1785          */
1786         public function isMovable() {
1787                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1788         }
1789
1790         /**
1791          * Can $wgUser read this page?
1792          *
1793          * @return Bool
1794          * @todo fold these checks into userCan()
1795          */
1796         public function userCanRead() {
1797                 global $wgUser, $wgGroupPermissions;
1798
1799                 static $useShortcut = null;
1800
1801                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1802                 if ( is_null( $useShortcut ) ) {
1803                         global $wgRevokePermissions;
1804                         $useShortcut = true;
1805                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1806                                 # Not a public wiki, so no shortcut
1807                                 $useShortcut = false;
1808                         } elseif ( !empty( $wgRevokePermissions ) ) {
1809                                 /**
1810                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1811                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1812                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1813                                  * reading is allowed.
1814                                  */
1815                                 foreach ( $wgRevokePermissions as $perms ) {
1816                                         if ( !empty( $perms['read'] ) ) {
1817                                                 # We might be removing the read right from the user, so no shortcut
1818                                                 $useShortcut = false;
1819                                                 break;
1820                                         }
1821                                 }
1822                         }
1823                 }
1824
1825                 $result = null;
1826                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1827                 if ( $result !== null ) {
1828                         return $result;
1829                 }
1830
1831                 # Shortcut for public wikis, allows skipping quite a bit of code
1832                 if ( $useShortcut ) {
1833                         return true;
1834                 }
1835
1836                 if ( $wgUser->isAllowed( 'read' ) ) {
1837                         return true;
1838                 } else {
1839                         global $wgWhitelistRead;
1840
1841                         # Always grant access to the login page.
1842                         # Even anons need to be able to log in.
1843                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1844                                 return true;
1845                         }
1846
1847                         # Bail out if there isn't whitelist
1848                         if ( !is_array( $wgWhitelistRead ) ) {
1849                                 return false;
1850                         }
1851
1852                         # Check for explicit whitelisting
1853                         $name = $this->getPrefixedText();
1854                         $dbName = $this->getPrefixedDBKey();
1855                         // Check with and without underscores
1856                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1857                                 return true;
1858
1859                         # Old settings might have the title prefixed with
1860                         # a colon for main-namespace pages
1861                         if ( $this->getNamespace() == NS_MAIN ) {
1862                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1863                                         return true;
1864                                 }
1865                         }
1866
1867                         # If it's a special page, ditch the subpage bit and check again
1868                         if ( $this->getNamespace() == NS_SPECIAL ) {
1869                                 $name = $this->getDBkey();
1870                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1871                                 if ( $name === false ) {
1872                                         # Invalid special page, but we show standard login required message
1873                                         return false;
1874                                 }
1875
1876                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1877                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1878                                         return true;
1879                                 }
1880                         }
1881
1882                 }
1883                 return false;
1884         }
1885
1886         /**
1887          * Is this the mainpage?
1888          * @note Title::newFromText seams to be sufficiently optimized by the title
1889          * cache that we don't need to over-optimize by doing direct comparisons and
1890          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1891          * ends up reporting something differently than $title->isMainPage();
1892          *
1893          * @return Bool
1894          */
1895         public function isMainPage() {
1896                 return $this->equals( Title::newMainPage() );
1897         }
1898
1899         /**
1900          * Is this a talk page of some sort?
1901          *
1902          * @return Bool
1903          */
1904         public function isTalkPage() {
1905                 return MWNamespace::isTalk( $this->getNamespace() );
1906         }
1907
1908         /**
1909          * Is this a subpage?
1910          *
1911          * @return Bool
1912          */
1913         public function isSubpage() {
1914                 return MWNamespace::hasSubpages( $this->mNamespace )
1915                         ? strpos( $this->getText(), '/' ) !== false
1916                         : false;
1917         }
1918
1919         /**
1920          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1921          *
1922          * @return Bool
1923          */
1924         public function hasSubpages() {
1925                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1926                         # Duh
1927                         return false;
1928                 }
1929
1930                 # We dynamically add a member variable for the purpose of this method
1931                 # alone to cache the result.  There's no point in having it hanging
1932                 # around uninitialized in every Title object; therefore we only add it
1933                 # if needed and don't declare it statically.
1934                 if ( isset( $this->mHasSubpages ) ) {
1935                         return $this->mHasSubpages;
1936                 }
1937
1938                 $subpages = $this->getSubpages( 1 );
1939                 if ( $subpages instanceof TitleArray ) {
1940                         return $this->mHasSubpages = (bool)$subpages->count();
1941                 }
1942                 return $this->mHasSubpages = false;
1943         }
1944
1945         /**
1946          * Get all subpages of this page.
1947          *
1948          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1949          * @return mixed TitleArray, or empty array if this page's namespace
1950          *  doesn't allow subpages
1951          */
1952         public function getSubpages( $limit = -1 ) {
1953                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1954                         return array();
1955                 }
1956
1957                 $dbr = wfGetDB( DB_SLAVE );
1958                 $conds['page_namespace'] = $this->getNamespace();
1959                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1960                 $options = array();
1961                 if ( $limit > -1 ) {
1962                         $options['LIMIT'] = $limit;
1963                 }
1964                 return $this->mSubpages = TitleArray::newFromResult(
1965                         $dbr->select( 'page',
1966                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1967                                 $conds,
1968                                 __METHOD__,
1969                                 $options
1970                         )
1971                 );
1972         }
1973
1974         /**
1975          * Does that page contain wikitext, or it is JS, CSS or whatever?
1976          *
1977          * @return Bool
1978          */
1979         public function isWikitextPage() {
1980                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
1981                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
1982                 return $retval;
1983         }
1984
1985         /**
1986          * Could this page contain custom CSS or JavaScript, based
1987          * on the title?
1988          *
1989          * @return Bool
1990          */
1991         public function isCssOrJsPage() {
1992                 $retval = $this->mNamespace == NS_MEDIAWIKI
1993                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1994                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
1995                 return $retval;
1996         }
1997
1998         /**
1999          * Is this a .css or .js subpage of a user page?
2000          * @return Bool
2001          */
2002         public function isCssJsSubpage() {
2003                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
2004         }
2005
2006         /**
2007          * Is this a *valid* .css or .js subpage of a user page?
2008          *
2009          * @return Bool
2010          * @deprecated since 1.17
2011          */
2012         public function isValidCssJsSubpage() {
2013                 return $this->isCssJsSubpage();
2014         }
2015
2016         /**
2017          * Trim down a .css or .js subpage title to get the corresponding skin name
2018          *
2019          * @return string containing skin name from .css or .js subpage title
2020          */
2021         public function getSkinFromCssJsSubpage() {
2022                 $subpage = explode( '/', $this->mTextform );
2023                 $subpage = $subpage[ count( $subpage ) - 1 ];
2024                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
2025         }
2026
2027         /**
2028          * Is this a .css subpage of a user page?
2029          *
2030          * @return Bool
2031          */
2032         public function isCssSubpage() {
2033                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2034         }
2035
2036         /**
2037          * Is this a .js subpage of a user page?
2038          *
2039          * @return Bool
2040          */
2041         public function isJsSubpage() {
2042                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2043         }
2044
2045         /**
2046          * Protect css subpages of user pages: can $wgUser edit
2047          * this page?
2048          *
2049          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2050          * @return Bool
2051          */
2052         public function userCanEditCssSubpage() {
2053                 global $wgUser;
2054                 wfDeprecated( __METHOD__ );
2055                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2056                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2057         }
2058
2059         /**
2060          * Protect js subpages of user pages: can $wgUser edit
2061          * this page?
2062          *
2063          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2064          * @return Bool
2065          */
2066         public function userCanEditJsSubpage() {
2067                 global $wgUser;
2068                 wfDeprecated( __METHOD__ );
2069                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2070                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2071         }
2072
2073         /**
2074          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2075          *
2076          * @return Bool If the page is subject to cascading restrictions.
2077          */
2078         public function isCascadeProtected() {
2079                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2080                 return ( $sources > 0 );
2081         }
2082
2083         /**
2084          * Cascading protection: Get the source of any cascading restrictions on this page.
2085          *
2086          * @param $getPages Bool Whether or not to retrieve the actual pages
2087          *        that the restrictions have come from.
2088          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2089          *     have come, false for none, or true if such restrictions exist, but $getPages
2090          *     was not set.  The restriction array is an array of each type, each of which
2091          *     contains a array of unique groups.
2092          */
2093         public function getCascadeProtectionSources( $getPages = true ) {
2094                 global $wgContLang;
2095                 $pagerestrictions = array();
2096
2097                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2098                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2099                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2100                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2101                 }
2102
2103                 wfProfileIn( __METHOD__ );
2104
2105                 $dbr = wfGetDB( DB_SLAVE );
2106
2107                 if ( $this->getNamespace() == NS_FILE ) {
2108                         $tables = array( 'imagelinks', 'page_restrictions' );
2109                         $where_clauses = array(
2110                                 'il_to' => $this->getDBkey(),
2111                                 'il_from=pr_page',
2112                                 'pr_cascade' => 1
2113                         );
2114                 } else {
2115                         $tables = array( 'templatelinks', 'page_restrictions' );
2116                         $where_clauses = array(
2117                                 'tl_namespace' => $this->getNamespace(),
2118                                 'tl_title' => $this->getDBkey(),
2119                                 'tl_from=pr_page',
2120                                 'pr_cascade' => 1
2121                         );
2122                 }
2123
2124                 if ( $getPages ) {
2125                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2126                                                    'pr_expiry', 'pr_type', 'pr_level' );
2127                         $where_clauses[] = 'page_id=pr_page';
2128                         $tables[] = 'page';
2129                 } else {
2130                         $cols = array( 'pr_expiry' );
2131                 }
2132
2133                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2134
2135                 $sources = $getPages ? array() : false;
2136                 $now = wfTimestampNow();
2137                 $purgeExpired = false;
2138
2139                 foreach ( $res as $row ) {
2140                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2141                         if ( $expiry > $now ) {
2142                                 if ( $getPages ) {
2143                                         $page_id = $row->pr_page;
2144                                         $page_ns = $row->page_namespace;
2145                                         $page_title = $row->page_title;
2146                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2147                                         # Add groups needed for each restriction type if its not already there
2148                                         # Make sure this restriction type still exists
2149
2150                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2151                                                 $pagerestrictions[$row->pr_type] = array();
2152                                         }
2153
2154                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2155                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2156                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2157                                         }
2158                                 } else {
2159                                         $sources = true;
2160                                 }
2161                         } else {
2162                                 // Trigger lazy purge of expired restrictions from the db
2163                                 $purgeExpired = true;
2164                         }
2165                 }
2166                 if ( $purgeExpired ) {
2167                         Title::purgeExpiredRestrictions();
2168                 }
2169
2170                 if ( $getPages ) {
2171                         $this->mCascadeSources = $sources;
2172                         $this->mCascadingRestrictions = $pagerestrictions;
2173                 } else {
2174                         $this->mHasCascadingRestrictions = $sources;
2175                 }
2176
2177                 wfProfileOut( __METHOD__ );
2178                 return array( $sources, $pagerestrictions );
2179         }
2180
2181         /**
2182          * Returns cascading restrictions for the current article
2183          *
2184          * @return Boolean
2185          */
2186         function areRestrictionsCascading() {
2187                 if ( !$this->mRestrictionsLoaded ) {
2188                         $this->loadRestrictions();
2189                 }
2190
2191                 return $this->mCascadeRestriction;
2192         }
2193
2194         /**
2195          * Loads a string into mRestrictions array
2196          *
2197          * @param $res Resource restrictions as an SQL result.
2198          * @param $oldFashionedRestrictions String comma-separated list of page
2199          *        restrictions from page table (pre 1.10)
2200          */
2201         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2202                 $rows = array();
2203
2204                 foreach ( $res as $row ) {
2205                         $rows[] = $row;
2206                 }
2207
2208                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2209         }
2210
2211         /**
2212          * Compiles list of active page restrictions from both page table (pre 1.10)
2213          * and page_restrictions table for this existing page.
2214          * Public for usage by LiquidThreads.
2215          *
2216          * @param $rows array of db result objects
2217          * @param $oldFashionedRestrictions string comma-separated list of page
2218          *        restrictions from page table (pre 1.10)
2219          */
2220         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2221                 global $wgContLang;
2222                 $dbr = wfGetDB( DB_SLAVE );
2223
2224                 $restrictionTypes = $this->getRestrictionTypes();
2225
2226                 foreach ( $restrictionTypes as $type ) {
2227                         $this->mRestrictions[$type] = array();
2228                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2229                 }
2230
2231                 $this->mCascadeRestriction = false;
2232
2233                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2234
2235                 if ( $oldFashionedRestrictions === null ) {
2236                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2237                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2238                 }
2239
2240                 if ( $oldFashionedRestrictions != '' ) {
2241
2242                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2243                                 $temp = explode( '=', trim( $restrict ) );
2244                                 if ( count( $temp ) == 1 ) {
2245                                         // old old format should be treated as edit/move restriction
2246                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2247                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2248                                 } else {
2249                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2250                                 }
2251                         }
2252
2253                         $this->mOldRestrictions = true;
2254
2255                 }
2256
2257                 if ( count( $rows ) ) {
2258                         # Current system - load second to make them override.
2259                         $now = wfTimestampNow();
2260                         $purgeExpired = false;
2261
2262                         # Cycle through all the restrictions.
2263                         foreach ( $rows as $row ) {
2264
2265                                 // Don't take care of restrictions types that aren't allowed
2266                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2267                                         continue;
2268
2269                                 // This code should be refactored, now that it's being used more generally,
2270                                 // But I don't really see any harm in leaving it in Block for now -werdna
2271                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2272
2273                                 // Only apply the restrictions if they haven't expired!
2274                                 if ( !$expiry || $expiry > $now ) {
2275                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2276                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2277
2278                                         $this->mCascadeRestriction |= $row->pr_cascade;
2279                                 } else {
2280                                         // Trigger a lazy purge of expired restrictions
2281                                         $purgeExpired = true;
2282                                 }
2283                         }
2284
2285                         if ( $purgeExpired ) {
2286                                 Title::purgeExpiredRestrictions();
2287                         }
2288                 }
2289
2290                 $this->mRestrictionsLoaded = true;
2291         }
2292
2293         /**
2294          * Load restrictions from the page_restrictions table
2295          *
2296          * @param $oldFashionedRestrictions String comma-separated list of page
2297          *        restrictions from page table (pre 1.10)
2298          */
2299         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2300                 global $wgContLang;
2301                 if ( !$this->mRestrictionsLoaded ) {
2302                         if ( $this->exists() ) {
2303                                 $dbr = wfGetDB( DB_SLAVE );
2304
2305                                 $res = $dbr->select(
2306                                         'page_restrictions',
2307                                         '*',
2308                                         array( 'pr_page' => $this->getArticleId() ),
2309                                         __METHOD__
2310                                 );
2311
2312                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2313                         } else {
2314                                 $title_protection = $this->getTitleProtection();
2315
2316                                 if ( $title_protection ) {
2317                                         $now = wfTimestampNow();
2318                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2319
2320                                         if ( !$expiry || $expiry > $now ) {
2321                                                 // Apply the restrictions
2322                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2323                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2324                                         } else { // Get rid of the old restrictions
2325                                                 Title::purgeExpiredRestrictions();
2326                                                 $this->mTitleProtection = false;
2327                                         }
2328                                 } else {
2329                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2330                                 }
2331                                 $this->mRestrictionsLoaded = true;
2332                         }
2333                 }
2334         }
2335
2336         /**
2337          * Purge expired restrictions from the page_restrictions table
2338          */
2339         static function purgeExpiredRestrictions() {
2340                 $dbw = wfGetDB( DB_MASTER );
2341                 $dbw->delete(
2342                         'page_restrictions',
2343                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2344                         __METHOD__
2345                 );
2346
2347                 $dbw->delete(
2348                         'protected_titles',
2349                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2350                         __METHOD__
2351                 );
2352         }
2353
2354         /**
2355          * Accessor/initialisation for mRestrictions
2356          *
2357          * @param $action String action that permission needs to be checked for
2358          * @return Array of Strings the array of groups allowed to edit this article
2359          */
2360         public function getRestrictions( $action ) {
2361                 if ( !$this->mRestrictionsLoaded ) {
2362                         $this->loadRestrictions();
2363                 }
2364                 return isset( $this->mRestrictions[$action] )
2365                                 ? $this->mRestrictions[$action]
2366                                 : array();
2367         }
2368
2369         /**
2370          * Get the expiry time for the restriction against a given action
2371          *
2372          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2373          *      or not protected at all, or false if the action is not recognised.
2374          */
2375         public function getRestrictionExpiry( $action ) {
2376                 if ( !$this->mRestrictionsLoaded ) {
2377                         $this->loadRestrictions();
2378                 }
2379                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2380         }
2381
2382         /**
2383          * Is there a version of this page in the deletion archive?
2384          *
2385          * @param $includeSuppressed Boolean Include suppressed revisions?
2386          * @return Int the number of archived revisions
2387          */
2388         public function isDeleted( $includeSuppressed = false ) {
2389                 if ( $this->getNamespace() < 0 ) {
2390                         $n = 0;
2391                 } else {
2392                         $dbr = wfGetDB( DB_SLAVE );
2393                         $conditions = array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() );
2394
2395                         if( !$includeSuppressed ) {
2396                                 $suppressedTextBits = Revision::DELETED_TEXT | Revision::DELETED_RESTRICTED;
2397                                 $conditions[] = $dbr->bitAnd('ar_deleted', $suppressedTextBits ) .
2398                                 ' != ' . $suppressedTextBits;
2399                         }
2400
2401                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2402                                 $conditions,
2403                                 __METHOD__
2404                         );
2405                         if ( $this->getNamespace() == NS_FILE ) {
2406                                 $fconditions = array( 'fa_name' => $this->getDBkey() );
2407                                 if( !$includeSuppressed ) {
2408                                         $suppressedTextBits = File::DELETED_FILE | File::DELETED_RESTRICTED;
2409                                         $fconditions[] = $dbr->bitAnd('fa_deleted', $suppressedTextBits ) .
2410                                         ' != ' . $suppressedTextBits;
2411                                 }
2412
2413                                 $n += $dbr->selectField( 'filearchive',
2414                                         'COUNT(*)',
2415                                         $fconditions,
2416                                         __METHOD__
2417                                 );
2418                         }
2419                 }
2420                 return (int)$n;
2421         }
2422
2423         /**
2424          * Is there a version of this page in the deletion archive?
2425          *
2426          * @return Boolean
2427          */
2428         public function isDeletedQuick() {
2429                 if ( $this->getNamespace() < 0 ) {
2430                         return false;
2431                 }
2432                 $dbr = wfGetDB( DB_SLAVE );
2433                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2434                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2435                         __METHOD__
2436                 );
2437                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2438                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2439                                 array( 'fa_name' => $this->getDBkey() ),
2440                                 __METHOD__
2441                         );
2442                 }
2443                 return $deleted;
2444         }
2445
2446         /**
2447          * Get the article ID for this Title from the link cache,
2448          * adding it if necessary
2449          *
2450          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2451          *  for update
2452          * @return Int the ID
2453          */
2454         public function getArticleID( $flags = 0 ) {
2455                 if ( $this->getNamespace() < 0 ) {
2456                         return $this->mArticleID = 0;
2457                 }
2458                 $linkCache = LinkCache::singleton();
2459                 if ( $flags & self::GAID_FOR_UPDATE ) {
2460                         $oldUpdate = $linkCache->forUpdate( true );
2461                         $linkCache->clearLink( $this );
2462                         $this->mArticleID = $linkCache->addLinkObj( $this );
2463                         $linkCache->forUpdate( $oldUpdate );
2464                 } else {
2465                         if ( -1 == $this->mArticleID ) {
2466                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2467                         }
2468                 }
2469                 return $this->mArticleID;
2470         }
2471
2472         /**
2473          * Is this an article that is a redirect page?
2474          * Uses link cache, adding it if necessary
2475          *
2476          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2477          * @return Bool
2478          */
2479         public function isRedirect( $flags = 0 ) {
2480                 if ( !is_null( $this->mRedirect ) ) {
2481                         return $this->mRedirect;
2482                 }
2483                 # Calling getArticleID() loads the field from cache as needed
2484                 if ( !$this->getArticleID( $flags ) ) {
2485                         return $this->mRedirect = false;
2486                 }
2487                 $linkCache = LinkCache::singleton();
2488                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2489
2490                 return $this->mRedirect;
2491         }
2492
2493         /**
2494          * What is the length of this page?
2495          * Uses link cache, adding it if necessary
2496          *
2497          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2498          * @return Int
2499          */
2500         public function getLength( $flags = 0 ) {
2501                 if ( $this->mLength != -1 ) {
2502                         return $this->mLength;
2503                 }
2504                 # Calling getArticleID() loads the field from cache as needed
2505                 if ( !$this->getArticleID( $flags ) ) {
2506                         return $this->mLength = 0;
2507                 }
2508                 $linkCache = LinkCache::singleton();
2509                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2510
2511                 return $this->mLength;
2512         }
2513
2514         /**
2515          * What is the page_latest field for this page?
2516          *
2517          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2518          * @return Int or 0 if the page doesn't exist
2519          */
2520         public function getLatestRevID( $flags = 0 ) {
2521                 if ( $this->mLatestID !== false ) {
2522                         return intval( $this->mLatestID );
2523                 }
2524                 # Calling getArticleID() loads the field from cache as needed
2525                 if ( !$this->getArticleID( $flags ) ) {
2526                         return $this->mLatestID = 0;
2527                 }
2528                 $linkCache = LinkCache::singleton();
2529                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2530
2531                 return $this->mLatestID;
2532         }
2533
2534         /**
2535          * This clears some fields in this object, and clears any associated
2536          * keys in the "bad links" section of the link cache.
2537          *
2538          * - This is called from Article::doEdit() and Article::insertOn() to allow
2539          * loading of the new page_id. It's also called from
2540          * Article::doDeleteArticle()
2541          *
2542          * @param $newid Int the new Article ID
2543          */
2544         public function resetArticleID( $newid ) {
2545                 $linkCache = LinkCache::singleton();
2546                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2547
2548                 if ( $newid === false ) {
2549                         $this->mArticleID = -1;
2550                 } else {
2551                         $this->mArticleID = intval( $newid );
2552                 }
2553                 $this->mRestrictionsLoaded = false;
2554                 $this->mRestrictions = array();
2555                 $this->mRedirect = null;
2556                 $this->mLength = -1;
2557                 $this->mLatestID = false;
2558         }
2559
2560         /**
2561          * Updates page_touched for this page; called from LinksUpdate.php
2562          *
2563          * @return Bool true if the update succeded
2564          */
2565         public function invalidateCache() {
2566                 if ( wfReadOnly() ) {
2567                         return;
2568                 }
2569                 $dbw = wfGetDB( DB_MASTER );
2570                 $success = $dbw->update(
2571                         'page',
2572                         array( 'page_touched' => $dbw->timestamp() ),
2573                         $this->pageCond(),
2574                         __METHOD__
2575                 );
2576                 HTMLFileCache::clearFileCache( $this );
2577                 return $success;
2578         }
2579
2580         /**
2581          * Prefix some arbitrary text with the namespace or interwiki prefix
2582          * of this object
2583          *
2584          * @param $name String the text
2585          * @return String the prefixed text
2586          * @private
2587          */
2588         private function prefix( $name ) {
2589                 $p = '';
2590                 if ( $this->mInterwiki != '' ) {
2591                         $p = $this->mInterwiki . ':';
2592                 }
2593
2594                 if ( 0 != $this->mNamespace ) {
2595                         $p .= $this->getNsText() . ':';
2596                 }
2597                 return $p . $name;
2598         }
2599
2600         /**
2601          * Returns a simple regex that will match on characters and sequences invalid in titles.
2602          * Note that this doesn't pick up many things that could be wrong with titles, but that
2603          * replacing this regex with something valid will make many titles valid.
2604          *
2605          * @return String regex string
2606          */
2607         static function getTitleInvalidRegex() {
2608                 static $rxTc = false;
2609                 if ( !$rxTc ) {
2610                         # Matching titles will be held as illegal.
2611                         $rxTc = '/' .
2612                                 # Any character not allowed is forbidden...
2613                                 '[^' . Title::legalChars() . ']' .
2614                                 # URL percent encoding sequences interfere with the ability
2615                                 # to round-trip titles -- you can't link to them consistently.
2616                                 '|%[0-9A-Fa-f]{2}' .
2617                                 # XML/HTML character references produce similar issues.
2618                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2619                                 '|&#[0-9]+;' .
2620                                 '|&#x[0-9A-Fa-f]+;' .
2621                                 '/S';
2622                 }
2623
2624                 return $rxTc;
2625         }
2626
2627         /**
2628          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2629          *
2630          * @param $text String containing title to capitalize
2631          * @param $ns int namespace index, defaults to NS_MAIN
2632          * @return String containing capitalized title
2633          */
2634         public static function capitalize( $text, $ns = NS_MAIN ) {
2635                 global $wgContLang;
2636
2637                 if ( MWNamespace::isCapitalized( $ns ) ) {
2638                         return $wgContLang->ucfirst( $text );
2639                 } else {
2640                         return $text;
2641                 }
2642         }
2643
2644         /**
2645          * Secure and split - main initialisation function for this object
2646          *
2647          * Assumes that mDbkeyform has been set, and is urldecoded
2648          * and uses underscores, but not otherwise munged.  This function
2649          * removes illegal characters, splits off the interwiki and
2650          * namespace prefixes, sets the other forms, and canonicalizes
2651          * everything.
2652          *
2653          * @return Bool true on success
2654          */
2655         private function secureAndSplit() {
2656                 global $wgContLang, $wgLocalInterwiki;
2657
2658                 # Initialisation
2659                 $this->mInterwiki = $this->mFragment = '';
2660                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2661
2662                 $dbkey = $this->mDbkeyform;
2663
2664                 # Strip Unicode bidi override characters.
2665                 # Sometimes they slip into cut-n-pasted page titles, where the
2666                 # override chars get included in list displays.
2667                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2668
2669                 # Clean up whitespace
2670                 # Note: use of the /u option on preg_replace here will cause
2671                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2672                 # conveniently disabling them.
2673                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2674                 $dbkey = trim( $dbkey, '_' );
2675
2676                 if ( $dbkey == '' ) {
2677                         return false;
2678                 }
2679
2680                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2681                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2682                         return false;
2683                 }
2684
2685                 $this->mDbkeyform = $dbkey;
2686
2687                 # Initial colon indicates main namespace rather than specified default
2688                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2689                 if ( ':' == $dbkey[0] ) {
2690                         $this->mNamespace = NS_MAIN;
2691                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2692                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2693                 }
2694
2695                 # Namespace or interwiki prefix
2696                 $firstPass = true;
2697                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2698                 do {
2699                         $m = array();
2700                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2701                                 $p = $m[1];
2702                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2703                                         # Ordinary namespace
2704                                         $dbkey = $m[2];
2705                                         $this->mNamespace = $ns;
2706                                         # For Talk:X pages, check if X has a "namespace" prefix
2707                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2708                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2709                                                         # Disallow Talk:File:x type titles...
2710                                                         return false;
2711                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2712                                                         # Disallow Talk:Interwiki:x type titles...
2713                                                         return false;
2714                                                 }
2715                                         }
2716                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2717                                         if ( !$firstPass ) {
2718                                                 # Can't make a local interwiki link to an interwiki link.
2719                                                 # That's just crazy!
2720                                                 return false;
2721                                         }
2722
2723                                         # Interwiki link
2724                                         $dbkey = $m[2];
2725                                         $this->mInterwiki = $wgContLang->lc( $p );
2726
2727                                         # Redundant interwiki prefix to the local wiki
2728                                         if ( $wgLocalInterwiki !== false
2729                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2730                                         {
2731                                                 if ( $dbkey == '' ) {
2732                                                         # Can't have an empty self-link
2733                                                         return false;
2734                                                 }
2735                                                 $this->mInterwiki = '';
2736                                                 $firstPass = false;
2737                                                 # Do another namespace split...
2738                                                 continue;
2739                                         }
2740
2741                                         # If there's an initial colon after the interwiki, that also
2742                                         # resets the default namespace
2743                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2744                                                 $this->mNamespace = NS_MAIN;
2745                                                 $dbkey = substr( $dbkey, 1 );
2746                                         }
2747                                 }
2748                                 # If there's no recognized interwiki or namespace,
2749                                 # then let the colon expression be part of the title.
2750                         }
2751                         break;
2752                 } while ( true );
2753
2754                 # We already know that some pages won't be in the database!
2755                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2756                         $this->mArticleID = 0;
2757                 }
2758                 $fragment = strstr( $dbkey, '#' );
2759                 if ( false !== $fragment ) {
2760                         $this->setFragment( $fragment );
2761                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2762                         # remove whitespace again: prevents "Foo_bar_#"
2763                         # becoming "Foo_bar_"
2764                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2765                 }
2766
2767                 # Reject illegal characters.
2768                 $rxTc = self::getTitleInvalidRegex();
2769                 if ( preg_match( $rxTc, $dbkey ) ) {
2770                         return false;
2771                 }
2772
2773                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2774                 # reachable due to the way web browsers deal with 'relative' URLs.
2775                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2776                 if ( strpos( $dbkey, '.' ) !== false &&
2777                          ( $dbkey === '.' || $dbkey === '..' ||
2778                            strpos( $dbkey, './' ) === 0  ||
2779                            strpos( $dbkey, '../' ) === 0 ||
2780                            strpos( $dbkey, '/./' ) !== false ||
2781                            strpos( $dbkey, '/../' ) !== false  ||
2782                            substr( $dbkey, -2 ) == '/.' ||
2783                            substr( $dbkey, -3 ) == '/..' ) )
2784                 {
2785                         return false;
2786                 }
2787
2788                 # Magic tilde sequences? Nu-uh!
2789                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2790                         return false;
2791                 }
2792
2793                 # Limit the size of titles to 255 bytes. This is typically the size of the
2794                 # underlying database field. We make an exception for special pages, which
2795                 # don't need to be stored in the database, and may edge over 255 bytes due
2796                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2797                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2798                   strlen( $dbkey ) > 512 )
2799                 {
2800                         return false;
2801                 }
2802
2803                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2804                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2805                 # other site might be case-sensitive.
2806                 $this->mUserCaseDBKey = $dbkey;
2807                 if ( $this->mInterwiki == '' ) {
2808                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2809                 }
2810
2811                 # Can't make a link to a namespace alone... "empty" local links can only be
2812                 # self-links with a fragment identifier.
2813                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2814                         return false;
2815                 }
2816
2817                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2818                 // IP names are not allowed for accounts, and can only be referring to
2819                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2820                 // there are numerous ways to present the same IP. Having sp:contribs scan
2821                 // them all is silly and having some show the edits and others not is
2822                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2823                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2824                         ? IP::sanitizeIP( $dbkey )
2825                         : $dbkey;
2826
2827                 // Any remaining initial :s are illegal.
2828                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2829                         return false;
2830                 }
2831
2832                 # Fill fields
2833                 $this->mDbkeyform = $dbkey;
2834                 $this->mUrlform = wfUrlencode( $dbkey );
2835
2836                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2837
2838                 return true;
2839         }
2840
2841         /**
2842          * Set the fragment for this title. Removes the first character from the
2843          * specified fragment before setting, so it assumes you're passing it with
2844          * an initial "#".
2845          *
2846          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2847          * Still in active use privately.
2848          *
2849          * @param $fragment String text
2850          */
2851         public function setFragment( $fragment ) {
2852                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2853         }
2854
2855         public function setInterwiki( $interwiki ) {
2856                 $this->mInterwiki = $interwiki;
2857         }
2858
2859         /**
2860          * Get a Title object associated with the talk page of this article
2861          *
2862          * @return Title the object for the talk page
2863          */
2864         public function getTalkPage() {
2865                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2866         }
2867
2868         /**
2869          * Get a title object associated with the subject page of this
2870          * talk page
2871          *
2872          * @return Title the object for the subject page
2873          */
2874         public function getSubjectPage() {
2875                 // Is this the same title?
2876                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2877                 if ( $this->getNamespace() == $subjectNS ) {
2878                         return $this;
2879                 }
2880                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2881         }
2882
2883         /**
2884          * Get an array of Title objects linking to this Title
2885          * Also stores the IDs in the link cache.
2886          *
2887          * WARNING: do not use this function on arbitrary user-supplied titles!
2888          * On heavily-used templates it will max out the memory.
2889          *
2890          * @param $options Array: may be FOR UPDATE
2891          * @param $table String: table name
2892          * @param $prefix String: fields prefix
2893          * @return Array of Title objects linking here
2894          */
2895         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2896                 $linkCache = LinkCache::singleton();
2897
2898                 if ( count( $options ) > 0 ) {
2899                         $db = wfGetDB( DB_MASTER );
2900                 } else {
2901                         $db = wfGetDB( DB_SLAVE );
2902                 }
2903
2904                 $res = $db->select(
2905                         array( 'page', $table ),
2906                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2907                         array(
2908                                 "{$prefix}_from=page_id",
2909                                 "{$prefix}_namespace" => $this->getNamespace(),
2910                                 "{$prefix}_title"     => $this->getDBkey() ),
2911                         __METHOD__,
2912                         $options
2913                 );
2914
2915                 $retVal = array();
2916                 if ( $db->numRows( $res ) ) {
2917                         foreach ( $res as $row ) {
2918                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2919                                 if ( $titleObj ) {
2920                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2921                                         $retVal[] = $titleObj;
2922                                 }
2923                         }
2924                 }
2925                 return $retVal;
2926         }
2927
2928         /**
2929          * Get an array of Title objects using this Title as a template
2930          * Also stores the IDs in the link cache.
2931          *
2932          * WARNING: do not use this function on arbitrary user-supplied titles!
2933          * On heavily-used templates it will max out the memory.
2934          *
2935          * @param $options Array: may be FOR UPDATE
2936          * @return Array of Title the Title objects linking here
2937          */
2938         public function getTemplateLinksTo( $options = array() ) {
2939                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2940         }
2941
2942         /**
2943          * Get an array of Title objects referring to non-existent articles linked from this page
2944          *
2945          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2946          * @return Array of Title the Title objects
2947          */
2948         public function getBrokenLinksFrom() {
2949                 if ( $this->getArticleId() == 0 ) {
2950                         # All links from article ID 0 are false positives
2951                         return array();
2952                 }
2953
2954                 $dbr = wfGetDB( DB_SLAVE );
2955                 $res = $dbr->select(
2956                         array( 'page', 'pagelinks' ),
2957                         array( 'pl_namespace', 'pl_title' ),
2958                         array(
2959                                 'pl_from' => $this->getArticleId(),
2960                                 'page_namespace IS NULL'
2961                         ),
2962                         __METHOD__, array(),
2963                         array(
2964                                 'page' => array(
2965                                         'LEFT JOIN',
2966                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2967                                 )
2968                         )
2969                 );
2970
2971                 $retVal = array();
2972                 foreach ( $res as $row ) {
2973                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2974                 }
2975                 return $retVal;
2976         }
2977
2978
2979         /**
2980          * Get a list of URLs to purge from the Squid cache when this
2981          * page changes
2982          *
2983          * @return Array of String the URLs
2984          */
2985         public function getSquidURLs() {
2986                 global $wgContLang;
2987
2988                 $urls = array(
2989                         $this->getInternalURL(),
2990                         $this->getInternalURL( 'action=history' )
2991                 );
2992
2993                 // purge variant urls as well
2994                 if ( $wgContLang->hasVariants() ) {
2995                         $variants = $wgContLang->getVariants();
2996                         foreach ( $variants as $vCode ) {
2997                                 $urls[] = $this->getInternalURL( '', $vCode );
2998                         }
2999                 }
3000
3001                 return $urls;
3002         }
3003
3004         /**
3005          * Purge all applicable Squid URLs
3006          */
3007         public function purgeSquid() {
3008                 global $wgUseSquid;
3009                 if ( $wgUseSquid ) {
3010                         $urls = $this->getSquidURLs();
3011                         $u = new SquidUpdate( $urls );
3012                         $u->doUpdate();
3013                 }
3014         }
3015
3016         /**
3017          * Move this page without authentication
3018          *
3019          * @param $nt Title the new page Title
3020          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3021          */
3022         public function moveNoAuth( &$nt ) {
3023                 return $this->moveTo( $nt, false );
3024         }
3025
3026         /**
3027          * Check whether a given move operation would be valid.
3028          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3029          *
3030          * @param $nt Title the new title
3031          * @param $auth Bool indicates whether $wgUser's permissions
3032          *  should be checked
3033          * @param $reason String is the log summary of the move, used for spam checking
3034          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3035          */
3036         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3037                 global $wgUser;
3038
3039                 $errors = array();
3040                 if ( !$nt ) {
3041                         // Normally we'd add this to $errors, but we'll get
3042                         // lots of syntax errors if $nt is not an object
3043                         return array( array( 'badtitletext' ) );
3044                 }
3045                 if ( $this->equals( $nt ) ) {
3046                         $errors[] = array( 'selfmove' );
3047                 }
3048                 if ( !$this->isMovable() ) {
3049                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3050                 }
3051                 if ( $nt->getInterwiki() != '' ) {
3052                         $errors[] = array( 'immobile-target-namespace-iw' );
3053                 }
3054                 if ( !$nt->isMovable() ) {
3055                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3056                 }
3057
3058                 $oldid = $this->getArticleID();
3059                 $newid = $nt->getArticleID();
3060
3061                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3062                         $errors[] = array( 'articleexists' );
3063                 }
3064                 if ( ( $this->getDBkey() == '' ) ||
3065                          ( !$oldid ) ||
3066                          ( $nt->getDBkey() == '' ) ) {
3067                         $errors[] = array( 'badarticleerror' );
3068                 }
3069
3070                 // Image-specific checks
3071                 if ( $this->getNamespace() == NS_FILE ) {
3072                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3073                 }
3074
3075                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3076                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3077                 }
3078
3079                 if ( $auth ) {
3080                         $errors = wfMergeErrorArrays( $errors,
3081                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3082                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3083                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3084                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3085                 }
3086
3087                 $match = EditPage::matchSummarySpamRegex( $reason );
3088                 if ( $match !== false ) {
3089                         // This is kind of lame, won't display nice
3090                         $errors[] = array( 'spamprotectiontext' );
3091                 }
3092
3093                 $err = null;
3094                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3095                         $errors[] = array( 'hookaborted', $err );
3096                 }
3097
3098                 # The move is allowed only if (1) the target doesn't exist, or
3099                 # (2) the target is a redirect to the source, and has no history
3100                 # (so we can undo bad moves right after they're done).
3101
3102                 if ( 0 != $newid ) { # Target exists; check for validity
3103                         if ( !$this->isValidMoveTarget( $nt ) ) {
3104                                 $errors[] = array( 'articleexists' );
3105                         }
3106                 } else {
3107                         $tp = $nt->getTitleProtection();
3108                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3109                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3110                                 $errors[] = array( 'cantmove-titleprotected' );
3111                         }
3112                 }
3113                 if ( empty( $errors ) ) {
3114                         return true;
3115                 }
3116                 return $errors;
3117         }
3118
3119         /**
3120          * Check if the requested move target is a valid file move target
3121          * @param Title $nt Target title
3122          * @return array List of errors
3123          */
3124         protected function validateFileMoveOperation( $nt ) {
3125                 global $wgUser;
3126
3127                 $errors = array();
3128
3129                 if ( $nt->getNamespace() != NS_FILE ) {
3130                         $errors[] = array( 'imagenocrossnamespace' );
3131                 }
3132
3133                 $file = wfLocalFile( $this );
3134                 if ( $file->exists() ) {
3135                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3136                                 $errors[] = array( 'imageinvalidfilename' );
3137                         }
3138                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3139                                 $errors[] = array( 'imagetypemismatch' );
3140                         }
3141                 }
3142
3143                 $destFile = wfLocalFile( $nt );
3144                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3145                         $errors[] = array( 'file-exists-sharedrepo' );
3146                 }
3147
3148                 return $errors;
3149         }
3150
3151         /**
3152          * Move a title to a new location
3153          *
3154          * @param $nt Title the new title
3155          * @param $auth Bool indicates whether $wgUser's permissions
3156          *  should be checked
3157          * @param $reason String the reason for the move
3158          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3159          *  Ignored if the user doesn't have the suppressredirect right.
3160          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3161          */
3162         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3163                 global $wgEnableInterwikiTemplatesTracking, $wgGlobalDatabase;
3164
3165                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3166                 if ( is_array( $err ) ) {
3167                         return $err;
3168                 }
3169
3170                 // If it is a file, move it first. It is done before all other moving stuff is
3171                 // done because it's hard to revert
3172                 $dbw = wfGetDB( DB_MASTER );
3173                 if ( $this->getNamespace() == NS_FILE ) {
3174                         $file = wfLocalFile( $this );
3175                         if ( $file->exists() ) {
3176                                 $status = $file->move( $nt );
3177                                 if ( !$status->isOk() ) {
3178                                         return $status->getErrorsArray();
3179                                 }
3180                         }
3181                 }
3182
3183                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3184                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3185                 $protected = $this->isProtected();
3186                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3187
3188                 // Do the actual move
3189                 $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3190                 if ( is_array( $err ) ) {
3191                         # @todo FIXME: What about the File we have already moved?
3192                         $dbw->rollback();
3193                         return $err;
3194                 }
3195
3196                 $redirid = $this->getArticleID();
3197
3198                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3199                 // cl_timestamp, which may disturb time-based lists on some sites.
3200                 $prefixes = $dbw->select(
3201                         'categorylinks',
3202                         array( 'cl_sortkey_prefix', 'cl_to' ),
3203                         array( 'cl_from' => $pageid ),
3204                         __METHOD__
3205                 );
3206                 foreach ( $prefixes as $prefixRow ) {
3207                         $prefix = $prefixRow->cl_sortkey_prefix;
3208                         $catTo = $prefixRow->cl_to;
3209                         $dbw->update( 'categorylinks',
3210                                 array(
3211                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3212                                                 $nt->getCategorySortkey( $prefix ) ),
3213                                         'cl_timestamp=cl_timestamp' ),
3214                                 array(
3215                                         'cl_from' => $pageid,
3216                                         'cl_to' => $catTo ),
3217                                 __METHOD__
3218                         );
3219                 }
3220
3221                 if ( $wgEnableInterwikiTemplatesTracking && $wgGlobalDatabase ) {
3222                         $dbw2 = wfGetDB( DB_MASTER, array(), $wgGlobalDatabase );
3223                         $dbw2->update( 'globaltemplatelinks',
3224                                                 array(  'gtl_from_namespace' => $nt->getNamespace(),
3225                                                                 'gtl_from_title' => $nt->getText() ),
3226                                                 array ( 'gtl_from_page' => $pageid ),
3227                                                 __METHOD__ );
3228                 }
3229
3230                 if ( $protected ) {
3231                         # Protect the redirect title as the title used to be...
3232                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3233                                 array(
3234                                         'pr_page'    => $redirid,
3235                                         'pr_type'    => 'pr_type',
3236                                         'pr_level'   => 'pr_level',
3237                                         'pr_cascade' => 'pr_cascade',
3238                                         'pr_user'    => 'pr_user',
3239                                         'pr_expiry'  => 'pr_expiry'
3240                                 ),
3241                                 array( 'pr_page' => $pageid ),
3242                                 __METHOD__,
3243                                 array( 'IGNORE' )
3244                         );
3245                         # Update the protection log
3246                         $log = new LogPage( 'protect' );
3247                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3248                         if ( $reason ) {
3249                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3250                         }
3251                         // @todo FIXME: $params?
3252                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3253                 }
3254
3255                 # Update watchlists
3256                 $oldnamespace = $this->getNamespace() & ~1;
3257                 $newnamespace = $nt->getNamespace() & ~1;
3258                 $oldtitle = $this->getDBkey();
3259                 $newtitle = $nt->getDBkey();
3260
3261                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3262                         WatchedItem::duplicateEntries( $this, $nt );
3263                 }
3264
3265                 # Update search engine
3266                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3267                 $u->doUpdate();
3268                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3269                 $u->doUpdate();
3270
3271                 $dbw->commit();
3272
3273                 # Update site_stats
3274                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3275                         # No longer a content page
3276                         # Not viewed, edited, removing
3277                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3278                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3279                         # Now a content page
3280                         # Not viewed, edited, adding
3281                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3282                 } elseif ( $pageCountChange ) {
3283                         # Redirect added
3284                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3285                 } else {
3286                         # Nothing special
3287                         $u = false;
3288                 }
3289                 if ( $u ) {
3290                         $u->doUpdate();
3291                 }
3292
3293                 # Update message cache for interface messages
3294                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3295                         # @bug 17860: old article can be deleted, if this the case,
3296                         # delete it from message cache
3297                         if ( $this->getArticleID() === 0 ) {
3298                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3299                         } else {
3300                                 $oldarticle = new Article( $this );
3301                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3302                         }
3303                 }
3304                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3305                         $newarticle = new Article( $nt );
3306                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3307                 }
3308
3309                 global $wgUser;
3310                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3311                 return true;
3312         }
3313
3314         /**
3315          * Move page to a title which is either a redirect to the
3316          * source page or nonexistent
3317          *
3318          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3319          * @param $reason String The reason for the move
3320          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3321          *   if the user doesn't have the suppressredirect right
3322          */
3323         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3324                 global $wgUser, $wgContLang, $wgEnableInterwikiTemplatesTracking, $wgGlobalDatabase;
3325
3326                 $moveOverRedirect = $nt->exists();
3327
3328                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3329                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3330
3331                 if ( $reason ) {
3332                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3333                 }
3334                 # Truncate for whole multibyte characters.
3335                 $comment = $wgContLang->truncate( $comment, 255 );
3336
3337                 $oldid = $this->getArticleID();
3338                 $latest = $this->getLatestRevID();
3339
3340                 $dbw = wfGetDB( DB_MASTER );
3341
3342                 if ( $moveOverRedirect ) {
3343                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3344
3345                         $newid = $nt->getArticleID();
3346                         $newns = $nt->getNamespace();
3347                         $newdbk = $nt->getDBkey();
3348
3349                         # Delete the old redirect. We don't save it to history since
3350                         # by definition if we've got here it's rather uninteresting.
3351                         # We have to remove it so that the next step doesn't trigger
3352                         # a conflict on the unique namespace+title index...
3353                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3354                         if ( !$dbw->cascadingDeletes() ) {
3355                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3356                                 global $wgUseTrackbacks;
3357                                 if ( $wgUseTrackbacks ) {
3358                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3359                                 }
3360                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3361                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3362                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3363                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3364                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3365                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3366                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3367                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3368                         }
3369                         // If the target page was recently created, it may have an entry in recentchanges still
3370                         $dbw->delete( 'recentchanges',
3371                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3372                                 __METHOD__
3373                         );
3374
3375                          if ( $wgEnableInterwikiTemplatesTracking && $wgGlobalDatabase ) {
3376                                 $dbw2 = wfGetDB( DB_MASTER, array(), $wgGlobalDatabase );
3377                                 $dbw2->delete( 'globaltemplatelinks',
3378                                                         array(  'gtl_from_wiki' => wfGetID(),
3379                                                                         'gtl_from_page' => $newid ),
3380                                                         __METHOD__ );
3381                 }
3382                 }
3383
3384                 # Save a null revision in the page's history notifying of the move
3385                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3386                 if ( !is_object( $nullRevision ) ) {
3387                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3388                 }
3389                 $nullRevId = $nullRevision->insertOn( $dbw );
3390
3391                 $now = wfTimestampNow();
3392                 # Change the name of the target page:
3393                 $dbw->update( 'page',
3394                         /* SET */ array(
3395                                 'page_touched'   => $dbw->timestamp( $now ),
3396                                 'page_namespace' => $nt->getNamespace(),
3397                                 'page_title'     => $nt->getDBkey(),
3398                                 'page_latest'    => $nullRevId,
3399                         ),
3400                         /* WHERE */ array( 'page_id' => $oldid ),
3401                         __METHOD__
3402                 );
3403                 $nt->resetArticleID( $oldid );
3404
3405                 $article = new Article( $nt );
3406                 wfRunHooks( 'NewRevisionFromEditComplete',
3407                         array( $article, $nullRevision, $latest, $wgUser ) );
3408                 $article->setCachedLastEditTime( $now );
3409
3410                 # Recreate the redirect, this time in the other direction.
3411                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3412                         $mwRedir = MagicWord::get( 'redirect' );
3413                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3414                         $redirectArticle = new Article( $this );
3415                         $newid = $redirectArticle->insertOn( $dbw );
3416                         if ( $newid ) { // sanity
3417                                 $redirectRevision = new Revision( array(
3418                                         'page'    => $newid,
3419                                         'comment' => $comment,
3420                                         'text'    => $redirectText ) );
3421                                 $redirectRevision->insertOn( $dbw );
3422                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3423
3424                                 wfRunHooks( 'NewRevisionFromEditComplete',
3425                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3426
3427                                 # Now, we record the link from the redirect to the new title.
3428                                 # It should have no other outgoing links...
3429                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3430                                 $dbw->insert( 'pagelinks',
3431                                         array(
3432                                                 'pl_from'      => $newid,
3433                                                 'pl_namespace' => $nt->getNamespace(),
3434                                                 'pl_title'     => $nt->getDBkey() ),
3435                                         __METHOD__ );
3436                         }
3437                         $redirectSuppressed = false;
3438                 } else {
3439                         $this->resetArticleID( 0 );
3440                         $redirectSuppressed = true;
3441                 }
3442
3443                 # Log the move
3444                 $log = new LogPage( 'move' );
3445                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3446                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3447
3448                 # Purge caches for old and new titles
3449                 if ( $moveOverRedirect ) {
3450                         # A simple purge is enough when moving over a redirect
3451                         $nt->purgeSquid();
3452                 } else {
3453                         # Purge caches as per article creation, including any pages that link to this title
3454                         Article::onArticleCreate( $nt );
3455                 }
3456                 $this->purgeSquid();
3457         }
3458
3459         /**
3460          * Move this page's subpages to be subpages of $nt
3461          *
3462          * @param $nt Title Move target
3463          * @param $auth bool Whether $wgUser's permissions should be checked
3464          * @param $reason string The reason for the move
3465          * @param $createRedirect bool Whether to create redirects from the old subpages to
3466          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3467          * @return mixed array with old page titles as keys, and strings (new page titles) or
3468          *     arrays (errors) as values, or an error array with numeric indices if no pages
3469          *     were moved
3470          */
3471         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3472                 global $wgMaximumMovedPages;
3473                 // Check permissions
3474                 if ( !$this->userCan( 'move-subpages' ) ) {
3475                         return array( 'cant-move-subpages' );
3476                 }
3477                 // Do the source and target namespaces support subpages?
3478                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3479                         return array( 'namespace-nosubpages',
3480                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3481                 }
3482                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3483                         return array( 'namespace-nosubpages',
3484                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3485                 }
3486
3487                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3488                 $retval = array();
3489                 $count = 0;
3490                 foreach ( $subpages as $oldSubpage ) {
3491                         $count++;
3492                         if ( $count > $wgMaximumMovedPages ) {
3493                                 $retval[$oldSubpage->getPrefixedTitle()] =
3494                                                 array( 'movepage-max-pages',
3495                                                         $wgMaximumMovedPages );
3496                                 break;
3497                         }
3498
3499                         // We don't know whether this function was called before
3500                         // or after moving the root page, so check both
3501                         // $this and $nt
3502                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3503                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3504                         {
3505                                 // When moving a page to a subpage of itself,
3506                                 // don't move it twice
3507                                 continue;
3508                         }
3509                         $newPageName = preg_replace(
3510                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3511                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3512                                         $oldSubpage->getDBkey() );
3513                         if ( $oldSubpage->isTalkPage() ) {
3514                                 $newNs = $nt->getTalkPage()->getNamespace();
3515                         } else {
3516                                 $newNs = $nt->getSubjectPage()->getNamespace();
3517                         }
3518                         # Bug 14385: we need makeTitleSafe because the new page names may
3519                         # be longer than 255 characters.
3520                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3521
3522                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3523                         if ( $success === true ) {
3524                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3525                         } else {
3526                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3527                         }
3528                 }
3529                 return $retval;
3530         }
3531
3532         /**
3533          * Checks if this page is just a one-rev redirect.
3534          * Adds lock, so don't use just for light purposes.
3535          *
3536          * @return Bool
3537          */
3538         public function isSingleRevRedirect() {
3539                 $dbw = wfGetDB( DB_MASTER );
3540                 # Is it a redirect?
3541                 $row = $dbw->selectRow( 'page',
3542                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3543                         $this->pageCond(),
3544                         __METHOD__,
3545                         array( 'FOR UPDATE' )
3546                 );
3547                 # Cache some fields we may want
3548                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3549                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3550                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3551                 if ( !$this->mRedirect ) {
3552                         return false;
3553                 }
3554                 # Does the article have a history?
3555                 $row = $dbw->selectField( array( 'page', 'revision' ),
3556                         'rev_id',
3557                         array( 'page_namespace' => $this->getNamespace(),
3558                                 'page_title' => $this->getDBkey(),
3559                                 'page_id=rev_page',
3560                                 'page_latest != rev_id'
3561                         ),
3562                         __METHOD__,
3563                         array( 'FOR UPDATE' )
3564                 );
3565                 # Return true if there was no history
3566                 return ( $row === false );
3567         }
3568
3569         /**
3570          * Checks if $this can be moved to a given Title
3571          * - Selects for update, so don't call it unless you mean business
3572          *
3573          * @param $nt Title the new title to check
3574          * @return Bool
3575          */
3576         public function isValidMoveTarget( $nt ) {
3577                 # Is it an existing file?
3578                 if ( $nt->getNamespace() == NS_FILE ) {
3579                         $file = wfLocalFile( $nt );
3580                         if ( $file->exists() ) {
3581                                 wfDebug( __METHOD__ . ": file exists\n" );
3582                                 return false;
3583                         }
3584                 }
3585                 # Is it a redirect with no history?
3586                 if ( !$nt->isSingleRevRedirect() ) {
3587                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3588                         return false;
3589                 }
3590                 # Get the article text
3591                 $rev = Revision::newFromTitle( $nt );
3592                 $text = $rev->getText();
3593                 # Does the redirect point to the source?
3594                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3595                 $m = array();
3596                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3597                         $redirTitle = Title::newFromText( $m[1] );
3598                         if ( !is_object( $redirTitle ) ||
3599                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3600                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3601                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3602                                 return false;
3603                         }
3604                 } else {
3605                         # Fail safe
3606                         wfDebug( __METHOD__ . ": failsafe\n" );
3607                         return false;
3608                 }
3609                 return true;
3610         }
3611
3612         /**
3613          * Can this title be added to a user's watchlist?
3614          *
3615          * @return Bool TRUE or FALSE
3616          */
3617         public function isWatchable() {
3618                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3619         }
3620
3621         /**
3622          * Get categories to which this Title belongs and return an array of
3623          * categories' names.
3624          *
3625          * @return Array of parents in the form:
3626          *        $parent => $currentarticle
3627          */
3628         public function getParentCategories() {
3629                 global $wgContLang;
3630
3631                 $data = array();
3632
3633                 $titleKey = $this->getArticleId();
3634
3635                 if ( $titleKey === 0 ) {
3636                         return $data;
3637                 }
3638
3639                 $dbr = wfGetDB( DB_SLAVE );
3640
3641                 $res = $dbr->select( 'categorylinks', '*',
3642                         array(
3643                                 'cl_from' => $titleKey,
3644                         ),
3645                         __METHOD__,
3646                         array()
3647                 );
3648
3649                 if ( $dbr->numRows( $res ) > 0 ) {
3650                         foreach ( $res as $row ) {
3651                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3652                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3653                         }
3654                 }
3655                 return $data;
3656         }
3657
3658         /**
3659          * Get a tree of parent categories
3660          *
3661          * @param $children Array with the children in the keys, to check for circular refs
3662          * @return Array Tree of parent categories
3663          */
3664         public function getParentCategoryTree( $children = array() ) {
3665                 $stack = array();
3666                 $parents = $this->getParentCategories();
3667
3668                 if ( $parents ) {
3669                         foreach ( $parents as $parent => $current ) {
3670                                 if ( array_key_exists( $parent, $children ) ) {
3671                                         # Circular reference
3672                                         $stack[$parent] = array();
3673                                 } else {
3674                                         $nt = Title::newFromText( $parent );
3675                                         if ( $nt ) {
3676                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3677                                         }
3678                                 }
3679                         }
3680                 }
3681
3682                 return $stack;
3683         }
3684
3685         /**
3686          * Get an associative array for selecting this title from
3687          * the "page" table
3688          *
3689          * @return Array suitable for the $where parameter of DB::select()
3690          */
3691         public function pageCond() {
3692                 if ( $this->mArticleID > 0 ) {
3693                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3694                         return array( 'page_id' => $this->mArticleID );
3695                 } else {
3696                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3697                 }
3698         }
3699
3700         /**
3701          * Get the revision ID of the previous revision
3702          *
3703          * @param $revId Int Revision ID. Get the revision that was before this one.
3704          * @param $flags Int Title::GAID_FOR_UPDATE
3705          * @return Int|Bool Old revision ID, or FALSE if none exists
3706          */
3707         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3708                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3709                 return $db->selectField( 'revision', 'rev_id',
3710                         array(
3711                                 'rev_page' => $this->getArticleId( $flags ),
3712                                 'rev_id < ' . intval( $revId )
3713                         ),
3714                         __METHOD__,
3715                         array( 'ORDER BY' => 'rev_id DESC' )
3716                 );
3717         }
3718
3719         /**
3720          * Get the revision ID of the next revision
3721          *
3722          * @param $revId Int Revision ID. Get the revision that was after this one.
3723          * @param $flags Int Title::GAID_FOR_UPDATE
3724          * @return Int|Bool Next revision ID, or FALSE if none exists
3725          */
3726         public function getNextRevisionID( $revId, $flags = 0 ) {
3727                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3728                 return $db->selectField( 'revision', 'rev_id',
3729                         array(
3730                                 'rev_page' => $this->getArticleId( $flags ),
3731                                 'rev_id > ' . intval( $revId )
3732                         ),
3733                         __METHOD__,
3734                         array( 'ORDER BY' => 'rev_id' )
3735                 );
3736         }
3737
3738         /**
3739          * Get the first revision of the page
3740          *
3741          * @param $flags Int Title::GAID_FOR_UPDATE
3742          * @return Revision|Null if page doesn't exist
3743          */
3744         public function getFirstRevision( $flags = 0 ) {
3745                 $pageId = $this->getArticleId( $flags );
3746                 if ( $pageId ) {
3747                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3748                         $row = $db->selectRow( 'revision', '*',
3749                                 array( 'rev_page' => $pageId ),
3750                                 __METHOD__,
3751                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3752                         );
3753                         if ( $row ) {
3754                                 return new Revision( $row );
3755                         }
3756                 }
3757                 return null;
3758         }
3759
3760         /**
3761          * Get the oldest revision timestamp of this page
3762          *
3763          * @param $flags Int Title::GAID_FOR_UPDATE
3764          * @return String: MW timestamp
3765          */
3766         public function getEarliestRevTime( $flags = 0 ) {
3767                 $rev = $this->getFirstRevision( $flags );
3768                 return $rev ? $rev->getTimestamp() : null;
3769         }
3770
3771         /**
3772          * Check if this is a new page
3773          *
3774          * @return bool
3775          */
3776         public function isNewPage() {
3777                 $dbr = wfGetDB( DB_SLAVE );
3778                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3779         }
3780
3781         /**
3782          * Get the number of revisions between the given revision.
3783          * Used for diffs and other things that really need it.
3784          *
3785          * @param $old int|Revision Old revision or rev ID (first before range)
3786          * @param $new int|Revision New revision or rev ID (first after range)
3787          * @return Int Number of revisions between these revisions.
3788          */
3789         public function countRevisionsBetween( $old, $new ) {
3790                 if ( !( $old instanceof Revision ) ) {
3791                         $old = Revision::newFromTitle( $this, (int)$old );
3792                 }
3793                 if ( !( $new instanceof Revision ) ) {
3794                         $new = Revision::newFromTitle( $this, (int)$new );
3795                 }
3796                 if ( !$old || !$new ) {
3797                         return 0; // nothing to compare
3798                 }
3799                 $dbr = wfGetDB( DB_SLAVE );
3800                 return (int)$dbr->selectField( 'revision', 'count(*)',
3801                         array(
3802                                 'rev_page' => $this->getArticleId(),
3803                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3804                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3805                         ),
3806                         __METHOD__
3807                 );
3808         }
3809
3810         /**
3811          * Get the number of authors between the given revision IDs.
3812          * Used for diffs and other things that really need it.
3813          *
3814          * @param $old int|Revision Old revision or rev ID (first before range)
3815          * @param $new int|Revision New revision or rev ID (first after range)
3816          * @param $limit Int Maximum number of authors
3817          * @return Int Number of revision authors between these revisions.
3818          */
3819         public function countAuthorsBetween( $old, $new, $limit ) {
3820                 if ( !( $old instanceof Revision ) ) {
3821                         $old = Revision::newFromTitle( $this, (int)$old );
3822                 }
3823                 if ( !( $new instanceof Revision ) ) {
3824                         $new = Revision::newFromTitle( $this, (int)$new );
3825                 }
3826                 if ( !$old || !$new ) {
3827                         return 0; // nothing to compare
3828                 }
3829                 $dbr = wfGetDB( DB_SLAVE );
3830                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3831                         array(
3832                                 'rev_page' => $this->getArticleID(),
3833                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3834                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3835                         ), __METHOD__,
3836                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3837                 );
3838                 return (int)$dbr->numRows( $res );
3839         }
3840
3841         /**
3842          * Compare with another title.
3843          *
3844          * @param $title Title
3845          * @return Bool
3846          */
3847         public function equals( Title $title ) {
3848                 // Note: === is necessary for proper matching of number-like titles.
3849                 return $this->getInterwiki() === $title->getInterwiki()
3850                         && $this->getNamespace() == $title->getNamespace()
3851                         && $this->getDBkey() === $title->getDBkey();
3852         }
3853
3854         /**
3855          * Callback for usort() to do title sorts by (namespace, title)
3856          *
3857          * @param $a Title
3858          * @param $b Title
3859          *
3860          * @return Integer: result of string comparison, or namespace comparison
3861          */
3862         public static function compare( $a, $b ) {
3863                 if ( $a->getNamespace() == $b->getNamespace() ) {
3864                         return strcmp( $a->getText(), $b->getText() );
3865                 } else {
3866                         return $a->getNamespace() - $b->getNamespace();
3867                 }
3868         }
3869
3870         /**
3871          * Return a string representation of this title
3872          *
3873          * @return String representation of this title
3874          */
3875         public function __toString() {
3876                 return $this->getPrefixedText();
3877         }
3878
3879         /**
3880          * Check if page exists.  For historical reasons, this function simply
3881          * checks for the existence of the title in the page table, and will
3882          * thus return false for interwiki links, special pages and the like.
3883          * If you want to know if a title can be meaningfully viewed, you should
3884          * probably call the isKnown() method instead.
3885          *
3886          * @return Bool
3887          */
3888         public function exists() {
3889                 return $this->getArticleId() != 0;
3890         }
3891
3892         /**
3893          * Should links to this title be shown as potentially viewable (i.e. as
3894          * "bluelinks"), even if there's no record by this title in the page
3895          * table?
3896          *
3897          * This function is semi-deprecated for public use, as well as somewhat
3898          * misleadingly named.  You probably just want to call isKnown(), which
3899          * calls this function internally.
3900          *
3901          * (ISSUE: Most of these checks are cheap, but the file existence check
3902          * can potentially be quite expensive.  Including it here fixes a lot of
3903          * existing code, but we might want to add an optional parameter to skip
3904          * it and any other expensive checks.)
3905          *
3906          * @return Bool
3907          */
3908         public function isAlwaysKnown() {
3909                 if ( $this->mInterwiki != '' ) {
3910                         return true;  // any interwiki link might be viewable, for all we know
3911                 }
3912                 switch( $this->mNamespace ) {
3913                         case NS_MEDIA:
3914                         case NS_FILE:
3915                                 // file exists, possibly in a foreign repo
3916                                 return (bool)wfFindFile( $this );
3917                         case NS_SPECIAL:
3918                                 // valid special page
3919                                 return SpecialPageFactory::exists( $this->getDBkey() );
3920                         case NS_MAIN:
3921                                 // selflink, possibly with fragment
3922                                 return $this->mDbkeyform == '';
3923                         case NS_MEDIAWIKI:
3924                                 // known system message
3925                                 return $this->getDefaultMessageText() !== false;
3926                         default:
3927                                 return false;
3928                 }
3929         }
3930
3931         /**
3932          * Does this title refer to a page that can (or might) be meaningfully
3933          * viewed?  In particular, this function may be used to determine if
3934          * links to the title should be rendered as "bluelinks" (as opposed to
3935          * "redlinks" to non-existent pages).
3936          *
3937          * @return Bool
3938          */
3939         public function isKnown() {
3940                 return $this->isAlwaysKnown() || $this->exists();
3941         }
3942
3943         /**
3944          * Does this page have source text?
3945          *
3946          * @return Boolean
3947          */
3948         public function hasSourceText() {
3949                 if ( $this->exists() ) {
3950                         return true;
3951                 }
3952
3953                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3954                         // If the page doesn't exist but is a known system message, default
3955                         // message content will be displayed, same for language subpages
3956                         return $this->getDefaultMessageText() !== false;
3957                 }
3958
3959                 return false;
3960         }
3961
3962         /**
3963          * Get the default message text or false if the message doesn't exist
3964          *
3965          * @return String or false
3966          */
3967         public function getDefaultMessageText() {
3968                 global $wgContLang;
3969
3970                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3971                         return false;
3972                 }
3973
3974                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3975                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3976
3977                 if ( $message->exists() ) {
3978                         return $message->plain();
3979                 } else {
3980                         return false;
3981                 }
3982         }
3983
3984         /**
3985          * Is this in a namespace that allows actual pages?
3986          *
3987          * @return Bool
3988          * @internal note -- uses hardcoded namespace index instead of constants
3989          */
3990         public function canExist() {
3991                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3992         }
3993
3994         /**
3995          * Update page_touched timestamps and send squid purge messages for
3996          * pages linking to this title. May be sent to the job queue depending
3997          * on the number of links. Typically called on create and delete.
3998          */
3999         public function touchLinks() {
4000                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4001                 $u->doUpdate();
4002
4003                 if ( $this->getNamespace() == NS_CATEGORY ) {
4004                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4005                         $u->doUpdate();
4006                 }
4007         }
4008
4009         /**
4010          * Get the last touched timestamp
4011          *
4012          * @param $db DatabaseBase: optional db
4013          * @return String last-touched timestamp
4014          */
4015         public function getTouched( $db = null ) {
4016                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4017                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4018                 return $touched;
4019         }
4020
4021         /**
4022          * Get the timestamp when this page was updated since the user last saw it.
4023          *
4024          * @param $user User
4025          * @return String|Null
4026          */
4027         public function getNotificationTimestamp( $user = null ) {
4028                 global $wgUser, $wgShowUpdatedMarker;
4029                 // Assume current user if none given
4030                 if ( !$user ) {
4031                         $user = $wgUser;
4032                 }
4033                 // Check cache first
4034                 $uid = $user->getId();
4035                 // avoid isset here, as it'll return false for null entries
4036                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4037                         return $this->mNotificationTimestamp[$uid];
4038                 }
4039                 if ( !$uid || !$wgShowUpdatedMarker ) {
4040                         return $this->mNotificationTimestamp[$uid] = false;
4041                 }
4042                 // Don't cache too much!
4043                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4044                         $this->mNotificationTimestamp = array();
4045                 }
4046                 $dbr = wfGetDB( DB_SLAVE );
4047                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4048                         'wl_notificationtimestamp',
4049                         array( 'wl_namespace' => $this->getNamespace(),
4050                                 'wl_title' => $this->getDBkey(),
4051                                 'wl_user' => $user->getId()
4052                         ),
4053                         __METHOD__
4054                 );
4055                 return $this->mNotificationTimestamp[$uid];
4056         }
4057
4058         /**
4059          * Get the trackback URL for this page
4060          *
4061          * @return String Trackback URL
4062          */
4063         public function trackbackURL() {
4064                 global $wgScriptPath, $wgServer, $wgScriptExtension;
4065
4066                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
4067                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
4068         }
4069
4070         /**
4071          * Get the trackback RDF for this page
4072          *
4073          * @return String Trackback RDF
4074          */
4075         public function trackbackRDF() {
4076                 $url = htmlspecialchars( $this->getFullURL() );
4077                 $title = htmlspecialchars( $this->getText() );
4078                 $tburl = $this->trackbackURL();
4079
4080                 // Autodiscovery RDF is placed in comments so HTML validator
4081                 // won't barf. This is a rather icky workaround, but seems
4082                 // frequently used by this kind of RDF thingy.
4083                 //
4084                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4085                 return "<!--
4086 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4087                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4088                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4089 <rdf:Description
4090    rdf:about=\"$url\"
4091    dc:identifier=\"$url\"
4092    dc:title=\"$title\"
4093    trackback:ping=\"$tburl\" />
4094 </rdf:RDF>
4095 -->";
4096         }
4097
4098         /**
4099          * Generate strings used for xml 'id' names in monobook tabs
4100          *
4101          * @param $prepend string defaults to 'nstab-'
4102          * @return String XML 'id' name
4103          */
4104         public function getNamespaceKey( $prepend = 'nstab-' ) {
4105                 global $wgContLang;
4106                 // Gets the subject namespace if this title
4107                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4108                 // Checks if cononical namespace name exists for namespace
4109                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4110                         // Uses canonical namespace name
4111                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4112                 } else {
4113                         // Uses text of namespace
4114                         $namespaceKey = $this->getSubjectNsText();
4115                 }
4116                 // Makes namespace key lowercase
4117                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4118                 // Uses main
4119                 if ( $namespaceKey == '' ) {
4120                         $namespaceKey = 'main';
4121                 }
4122                 // Changes file to image for backwards compatibility
4123                 if ( $namespaceKey == 'file' ) {
4124                         $namespaceKey = 'image';
4125                 }
4126                 return $prepend . $namespaceKey;
4127         }
4128
4129         /**
4130          * Returns true if this is a special page.
4131          *
4132          * @return boolean
4133          */
4134         public function isSpecialPage() {
4135                 return $this->getNamespace() == NS_SPECIAL;
4136         }
4137
4138         /**
4139          * Returns true if this title resolves to the named special page
4140          *
4141          * @param $name String The special page name
4142          * @return boolean
4143          */
4144         public function isSpecial( $name ) {
4145                 if ( $this->getNamespace() == NS_SPECIAL ) {
4146                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4147                         if ( $name == $thisName ) {
4148                                 return true;
4149                         }
4150                 }
4151                 return false;
4152         }
4153
4154         /**
4155          * If the Title refers to a special page alias which is not the local default, resolve
4156          * the alias, and localise the name as necessary.  Otherwise, return $this
4157          *
4158          * @return Title
4159          */
4160         public function fixSpecialName() {
4161                 if ( $this->getNamespace() == NS_SPECIAL ) {
4162                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4163                         if ( $canonicalName ) {
4164                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4165                                 if ( $localName != $this->mDbkeyform ) {
4166                                         return Title::makeTitle( NS_SPECIAL, $localName );
4167                                 }
4168                         }
4169                 }
4170                 return $this;
4171         }
4172
4173         /**
4174          * Is this Title in a namespace which contains content?
4175          * In other words, is this a content page, for the purposes of calculating
4176          * statistics, etc?
4177          *
4178          * @return Boolean
4179          */
4180         public function isContentPage() {
4181                 return MWNamespace::isContent( $this->getNamespace() );
4182         }
4183
4184         /**
4185          * Get all extant redirects to this Title
4186          *
4187          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4188          * @return Array of Title redirects to this title
4189          */
4190         public function getRedirectsHere( $ns = null ) {
4191                 $redirs = array();
4192
4193                 $dbr = wfGetDB( DB_SLAVE );
4194                 $where = array(
4195                         'rd_namespace' => $this->getNamespace(),
4196                         'rd_title' => $this->getDBkey(),
4197                         'rd_from = page_id'
4198                 );
4199                 if ( !is_null( $ns ) ) {
4200                         $where['page_namespace'] = $ns;
4201                 }
4202
4203                 $res = $dbr->select(
4204                         array( 'redirect', 'page' ),
4205                         array( 'page_namespace', 'page_title' ),
4206                         $where,
4207                         __METHOD__
4208                 );
4209
4210                 foreach ( $res as $row ) {
4211                         $redirs[] = self::newFromRow( $row );
4212                 }
4213                 return $redirs;
4214         }
4215
4216         /**
4217          * Check if this Title is a valid redirect target
4218          *
4219          * @return Bool
4220          */
4221         public function isValidRedirectTarget() {
4222                 global $wgInvalidRedirectTargets;
4223
4224                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4225                 if ( $this->isSpecial( 'Userlogout' ) ) {
4226                         return false;
4227                 }
4228
4229                 foreach ( $wgInvalidRedirectTargets as $target ) {
4230                         if ( $this->isSpecial( $target ) ) {
4231                                 return false;
4232                         }
4233                 }
4234
4235                 return true;
4236         }
4237
4238         /**
4239          * Get a backlink cache object
4240          *
4241          * @return object BacklinkCache
4242          */
4243         function getBacklinkCache() {
4244                 if ( is_null( $this->mBacklinkCache ) ) {
4245                         $this->mBacklinkCache = new BacklinkCache( $this );
4246                 }
4247                 return $this->mBacklinkCache;
4248         }
4249
4250         /**
4251          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4252          *
4253          * @return Boolean
4254          */
4255         public function canUseNoindex() {
4256                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4257
4258                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4259                         ? $wgContentNamespaces
4260                         : $wgExemptFromUserRobotsControl;
4261
4262                 return !in_array( $this->mNamespace, $bannedNamespaces );
4263
4264         }
4265
4266         /**
4267          * Returns restriction types for the current Title
4268          *
4269          * @return array applicable restriction types
4270          */
4271         public function getRestrictionTypes() {
4272                 if ( $this->getNamespace() == NS_SPECIAL ) {
4273                         return array();
4274                 }
4275
4276                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4277
4278                 if ( $this->getNamespace() != NS_FILE ) {
4279                         # Remove the upload restriction for non-file titles
4280                         $types = array_diff( $types, array( 'upload' ) );
4281                 }
4282
4283                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4284
4285                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4286                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4287
4288                 return $types;
4289         }
4290         /**
4291          * Get a filtered list of all restriction types supported by this wiki.
4292          * @param bool $exists True to get all restriction types that apply to
4293          * titles that do exist, False for all restriction types that apply to
4294          * titles that do not exist
4295          * @return array
4296          */
4297         public static function getFilteredRestrictionTypes( $exists = true ) {
4298                 global $wgRestrictionTypes;
4299                 $types = $wgRestrictionTypes;
4300                 if ( $exists ) {
4301                         # Remove the create restriction for existing titles
4302                         $types = array_diff( $types, array( 'create' ) );
4303                 } else {
4304                         # Only the create and upload restrictions apply to non-existing titles
4305                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4306                 }
4307                 return $types;
4308         }
4309
4310         /**
4311          * Returns the raw sort key to be used for categories, with the specified
4312          * prefix.  This will be fed to Collation::getSortKey() to get a
4313          * binary sortkey that can be used for actual sorting.
4314          *
4315          * @param $prefix string The prefix to be used, specified using
4316          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4317          *   prefix.
4318          * @return string
4319          */
4320         public function getCategorySortkey( $prefix = '' ) {
4321                 $unprefixed = $this->getText();
4322
4323                 // Anything that uses this hook should only depend
4324                 // on the Title object passed in, and should probably
4325                 // tell the users to run updateCollations.php --force
4326                 // in order to re-sort existing category relations.
4327                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4328                 if ( $prefix !== '' ) {
4329                         # Separate with a line feed, so the unprefixed part is only used as
4330                         # a tiebreaker when two pages have the exact same prefix.
4331                         # In UCA, tab is the only character that can sort above LF
4332                         # so we strip both of them from the original prefix.
4333                         $prefix = strtr( $prefix, "\n\t", '  ' );
4334                         return "$prefix\n$unprefixed";
4335                 }
4336                 return $unprefixed;
4337         }
4338
4339         /**
4340          * Get the language in which the content of this page is written.
4341          * Defaults to $wgContLang, but in certain cases it can be e.g.
4342          * $wgLang (such as special pages, which are in the user language).
4343          *
4344          * @since 1.18
4345          * @return object Language
4346          */
4347         public function getPageLanguage() {
4348                 global $wgLang;
4349                 if ( $this->getNamespace() == NS_SPECIAL ) {
4350                         // special pages are in the user language
4351                         return $wgLang;
4352                 } elseif ( $this->isRedirect() ) {
4353                         // the arrow on a redirect page is aligned according to the user language
4354                         return $wgLang;
4355                 } elseif ( $this->isCssOrJsPage() ) {
4356                         // css/js should always be LTR and is, in fact, English
4357                         return wfGetLangObj( 'en' );
4358                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4359                         // Parse mediawiki messages with correct target language
4360                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4361                         return wfGetLangObj( $lang );
4362                 }
4363                 global $wgContLang;
4364                 // If nothing special, it should be in the wiki content language
4365                 $pageLang = $wgContLang;
4366                 // Hook at the end because we don't want to override the above stuff
4367                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4368                 return wfGetLangObj( $pageLang );
4369         }
4370 }