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                 global $wgServer, $wgRequest;
 853
 854                 if ( is_array( $query ) ) {
 855                         $query = wfArrayToCGI( $query );
 856                 }
 857
 858                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 859                 if ( !$interwiki ) {
 860                         $url = $this->getLocalURL( $query, $variant );
 861
 862                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 863                         // Correct fix would be to move the prepending elsewhere.
 864                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 865                                 $url = $wgServer . $url;
 866                         }
 867                 } else {
 868                         $baseUrl = $interwiki->getURL();
 869
 870                         $namespace = wfUrlencode( $this->getNsText() );
 871                         if ( $namespace != '' ) {
 872                                 # Can this actually happen? Interwikis shouldn't be parsed.
 873                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 874                                 $namespace .= ':';
 875                         }
 876                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 877                         $url = wfAppendQuery( $url, $query );
 878                 }
 879
 880                 # Finally, add the fragment.
 881                 $url .= $this->getFragmentForURL();
 882
 883                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 884                 return $url;
 885         }
 886
 887         /**
 888          * Get a URL with no fragment or server name.  If this page is generated
 889          * with action=render, $wgServer is prepended.
 890          *
 891          * @param $query Mixed: an optional query string; if not specified,
 892          *   $wgArticlePath will be used.  Can be specified as an associative array
 893          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 894          *   URL-escaped).
 895          * @param $variant String language variant of url (for sr, zh..)
 896          * @return String the URL
 897          */
 898         public function getLocalURL( $query = '', $variant = false ) {
 899                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 900                 global $wgVariantArticlePath, $wgContLang;
 901
 902                 if ( is_array( $query ) ) {
 903                         $query = wfArrayToCGI( $query );
 904                 }
 905
 906                 if ( $this->isExternal() ) {
 907                         $url = $this->getFullURL();
 908                         if ( $query ) {
 909                                 // This is currently only used for edit section links in the
 910                                 // context of interwiki transclusion. In theory we should
 911                                 // append the query to the end of any existing query string,
 912                                 // but interwiki transclusion is already broken in that case.
 913                                 $url .= "?$query";
 914                         }
 915                 } else {
 916                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 917                         if ( $query == '' ) {
 918                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 919                                         if ( !$wgVariantArticlePath ) {
 920                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 921                                         } else {
 922                                                 $variantArticlePath = $wgVariantArticlePath;
 923                                         }
 924                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 925                                         $url = str_replace( '$1', $dbkey, $url  );
 926                                 } else {
 927                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 928                                 }
 929                         } else {
 930                                 global $wgActionPaths;
 931                                 $url = false;
 932                                 $matches = array();
 933                                 if ( !empty( $wgActionPaths ) &&
 934                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 935                                 {
 936                                         $action = urldecode( $matches[2] );
 937                                         if ( isset( $wgActionPaths[$action] ) ) {
 938                                                 $query = $matches[1];
 939                                                 if ( isset( $matches[4] ) ) {
 940                                                         $query .= $matches[4];
 941                                                 }
 942                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 943                                                 if ( $query != '' ) {
 944                                                         $url = wfAppendQuery( $url, $query );
 945                                                 }
 946                                         }
 947                                 }
 948
 949                                 if ( $url === false ) {
 950                                         if ( $query == '-' ) {
 951                                                 $query = '';
 952                                         }
 953                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 954                                 }
 955                         }
 956
 957                         // @todo FIXME: This causes breakage in various places when we
 958                         // actually expected a local URL and end up with dupe prefixes.
 959                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 960                                 $url = $wgServer . $url;
 961                         }
 962                 }
 963                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 964                 return $url;
 965         }
 966
 967         /**
 968          * Get a URL that's the simplest URL that will be valid to link, locally,
 969          * to the current Title.  It includes the fragment, but does not include
 970          * the server unless action=render is used (or the link is external).  If
 971          * there's a fragment but the prefixed text is empty, we just return a link
 972          * to the fragment.
 973          *
 974          * The result obviously should not be URL-escaped, but does need to be
 975          * HTML-escaped if it's being output in HTML.
 976          *
 977          * @param $query Array of Strings An associative array of key => value pairs for the
 978          *   query string.  Keys and values will be escaped.
 979          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 980          *   for external links.  Default is "false" (same variant as current page,
 981          *   for anonymous users).
 982          * @return String the URL
 983          */
 984         public function getLinkUrl( $query = array(), $variant = false ) {
 985                 wfProfileIn( __METHOD__ );
 986                 if ( $this->isExternal() ) {
 987                         $ret = $this->getFullURL( $query );
 988                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 989                         $ret = $this->getFragmentForURL();
 990                 } else {
 991                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 992                 }
 993                 wfProfileOut( __METHOD__ );
 994                 return $ret;
 995         }
 996
 997         /**
 998          * Get an HTML-escaped version of the URL form, suitable for
 999          * using in a link, without a server name or fragment
1000          *
1001          * @param $query String an optional query string
1002          * @return String the URL
1003          */
1004         public function escapeLocalURL( $query = '' ) {
1005                 return htmlspecialchars( $this->getLocalURL( $query ) );
1006         }
1007
1008         /**
1009          * Get an HTML-escaped version of the URL form, suitable for
1010          * using in a link, including the server name and fragment
1011          *
1012          * @param $query String an optional query string
1013          * @return String the URL
1014          */
1015         public function escapeFullURL( $query = '' ) {
1016                 return htmlspecialchars( $this->getFullURL( $query ) );
1017         }
1018
1019         /**
1020          * Get the URL form for an internal link.
1021          * - Used in various Squid-related code, in case we have a different
1022          * internal hostname for the server from the exposed one.
1023          *
1024          * @param $query String an optional query string
1025          * @param $variant String language variant of url (for sr, zh..)
1026          * @return String the URL
1027          */
1028         public function getInternalURL( $query = '', $variant = false ) {
1029                 if ( $this->isExternal( ) ) {
1030                         $server = '';
1031                 } else {
1032                         global $wgInternalServer, $wgServer;
1033                         $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1034                 }
1035
1036                 $url = $server . $this->getLocalURL( $query, $variant );
1037                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1038                 return $url;
1039         }
1040
1041         /**
1042          * Get the edit URL for this Title
1043          *
1044          * @return String the URL, or a null string if this is an
1045          *  interwiki link
1046          */
1047         public function getEditURL() {
1048                 if ( $this->mInterwiki != '' ) {
1049                         return '';
1050                 }
1051                 $s = $this->getLocalURL( 'action=edit' );
1052
1053                 return $s;
1054         }
1055
1056         /**
1057          * Get the HTML-escaped displayable text form.
1058          * Used for the title field in <a> tags.
1059          *
1060          * @return String the text, including any prefixes
1061          */
1062         public function getEscapedText() {
1063                 return htmlspecialchars( $this->getPrefixedText() );
1064         }
1065
1066         /**
1067          * Is this Title interwiki?
1068          *
1069          * @return Bool
1070          */
1071         public function isExternal() {
1072                 return ( $this->mInterwiki != '' );
1073         }
1074
1075         /**
1076          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1077          *
1078          * @param $action String Action to check (default: edit)
1079          * @return Bool
1080          */
1081         public function isSemiProtected( $action = 'edit' ) {
1082                 if ( $this->exists() ) {
1083                         $restrictions = $this->getRestrictions( $action );
1084                         if ( count( $restrictions ) > 0 ) {
1085                                 foreach ( $restrictions as $restriction ) {
1086                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1087                                                 return false;
1088                                         }
1089                                 }
1090                         } else {
1091                                 # Not protected
1092                                 return false;
1093                         }
1094                         return true;
1095                 } else {
1096                         # If it doesn't exist, it can't be protected
1097                         return false;
1098                 }
1099         }
1100
1101         /**
1102          * Does the title correspond to a protected article?
1103          *
1104          * @param $action String the action the page is protected from,
1105          * by default checks all actions.
1106          * @return Bool
1107          */
1108         public function isProtected( $action = '' ) {
1109                 global $wgRestrictionLevels;
1110
1111                 $restrictionTypes = $this->getRestrictionTypes();
1112
1113                 # Special pages have inherent protection
1114                 if( $this->getNamespace() == NS_SPECIAL ) {
1115                         return true;
1116                 }
1117
1118                 # Check regular protection levels
1119                 foreach ( $restrictionTypes as $type ) {
1120                         if ( $action == $type || $action == '' ) {
1121                                 $r = $this->getRestrictions( $type );
1122                                 foreach ( $wgRestrictionLevels as $level ) {
1123                                         if ( in_array( $level, $r ) && $level != '' ) {
1124                                                 return true;
1125                                         }
1126                                 }
1127                         }
1128                 }
1129
1130                 return false;
1131         }
1132
1133         /**
1134          * Is this a conversion table for the LanguageConverter?
1135          *
1136          * @return Bool
1137          */
1138         public function isConversionTable() {
1139                 if(
1140                         $this->getNamespace() == NS_MEDIAWIKI &&
1141                         strpos( $this->getText(), 'Conversiontable' ) !== false
1142                 )
1143                 {
1144                         return true;
1145                 }
1146
1147                 return false;
1148         }
1149
1150         /**
1151          * Is $wgUser watching this page?
1152          *
1153          * @return Bool
1154          */
1155         public function userIsWatching() {
1156                 global $wgUser;
1157
1158                 if ( is_null( $this->mWatched ) ) {
1159                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1160                                 $this->mWatched = false;
1161                         } else {
1162                                 $this->mWatched = $wgUser->isWatched( $this );
1163                         }
1164                 }
1165                 return $this->mWatched;
1166         }
1167
1168         /**
1169          * Can $wgUser perform $action on this page?
1170          * This skips potentially expensive cascading permission checks
1171          * as well as avoids expensive error formatting
1172          *
1173          * Suitable for use for nonessential UI controls in common cases, but
1174          * _not_ for functional access control.
1175          *
1176          * May provide false positives, but should never provide a false negative.
1177          *
1178          * @param $action String action that permission needs to be checked for
1179          * @return Bool
1180          */
1181         public function quickUserCan( $action ) {
1182                 return $this->userCan( $action, false );
1183         }
1184
1185         /**
1186          * Determines if $user is unable to edit this page because it has been protected
1187          * by $wgNamespaceProtection.
1188          *
1189          * @param $user User object to check permissions
1190          * @return Bool
1191          */
1192         public function isNamespaceProtected( User $user ) {
1193                 global $wgNamespaceProtection;
1194
1195                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1196                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1197                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1198                                         return true;
1199                                 }
1200                         }
1201                 }
1202                 return false;
1203         }
1204
1205         /**
1206          * Can $wgUser perform $action on this page?
1207          *
1208          * @param $action String action that permission needs to be checked for
1209          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1210          * @return Bool
1211          */
1212         public function userCan( $action, $doExpensiveQueries = true ) {
1213                 global $wgUser;
1214                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1215         }
1216
1217         /**
1218          * Can $user perform $action on this page?
1219          *
1220          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1221          *
1222          * @param $action String action that permission needs to be checked for
1223          * @param $user User to check
1224          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1225          *   skipping checks for cascading protections and user blocks.
1226          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1227          * @return Array of arguments to wfMsg to explain permissions problems.
1228          */
1229         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1230                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1231
1232                 // Remove the errors being ignored.
1233                 foreach ( $errors as $index => $error ) {
1234                         $error_key = is_array( $error ) ? $error[0] : $error;
1235
1236                         if ( in_array( $error_key, $ignoreErrors ) ) {
1237                                 unset( $errors[$index] );
1238                         }
1239                 }
1240
1241                 return $errors;
1242         }
1243
1244         /**
1245          * Permissions checks that fail most often, and which are easiest to test.
1246          *
1247          * @param $action String the action to check
1248          * @param $user User user to check
1249          * @param $errors Array list of current errors
1250          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1251          * @param $short Boolean short circuit on first error
1252          *
1253          * @return Array list of errors
1254          */
1255         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1256                 $ns = $this->getNamespace();
1257
1258                 if ( $action == 'create' ) {
1259                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1260                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1261                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1262                         }
1263                 } elseif ( $action == 'move' ) {
1264                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1265                                         && $ns == NS_USER && !$this->isSubpage() ) {
1266                                 // Show user page-specific message only if the user can move other pages
1267                                 $errors[] = array( 'cant-move-user-page' );
1268                         }
1269
1270                         // Check if user is allowed to move files if it's a file
1271                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1272                                 $errors[] = array( 'movenotallowedfile' );
1273                         }
1274
1275                         if ( !$user->isAllowed( 'move', $ns) ) {
1276                                 // User can't move anything
1277
1278                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1279                                         array( 'user' ), $ns ), true );
1280                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1281                                         array( 'autoconfirmed' ), $ns ), true );
1282
1283                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1284                                         // custom message if logged-in users without any special rights can move
1285                                         $errors[] = array( 'movenologintext' );
1286                                 } else {
1287                                         $errors[] = array( 'movenotallowed' );
1288                                 }
1289                         }
1290                 } elseif ( $action == 'move-target' ) {
1291                         if ( !$user->isAllowed( 'move', $ns ) ) {
1292                                 // User can't move anything
1293                                 $errors[] = array( 'movenotallowed' );
1294                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1295                                         && $ns == NS_USER && !$this->isSubpage() ) {
1296                                 // Show user page-specific message only if the user can move other pages
1297                                 $errors[] = array( 'cant-move-to-user-page' );
1298                         }
1299                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1300                         // We avoid expensive display logic for quickUserCan's and such
1301                         $groups = false;
1302                         if ( !$short ) {
1303                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1304                                         User::getGroupsWithPermission( $action, $ns ) );
1305                         }
1306
1307                         if ( $groups ) {
1308                                 global $wgLang;
1309                                 $return = array(
1310                                         'badaccess-groups',
1311                                         $wgLang->commaList( $groups ),
1312                                         count( $groups )
1313                                 );
1314                         } else {
1315                                 $return = array( 'badaccess-group0' );
1316                         }
1317                         $errors[] = $return;
1318                 }
1319
1320                 return $errors;
1321         }
1322
1323         /**
1324          * Add the resulting error code to the errors array
1325          *
1326          * @param $errors Array list of current errors
1327          * @param $result Mixed result of errors
1328          *
1329          * @return Array list of errors
1330          */
1331         private function resultToError( $errors, $result ) {
1332                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1333                         // A single array representing an error
1334                         $errors[] = $result;
1335                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1336                         // A nested array representing multiple errors
1337                         $errors = array_merge( $errors, $result );
1338                 } elseif ( $result !== '' && is_string( $result ) ) {
1339                         // A string representing a message-id
1340                         $errors[] = array( $result );
1341                 } elseif ( $result === false ) {
1342                         // a generic "We don't want them to do that"
1343                         $errors[] = array( 'badaccess-group0' );
1344                 }
1345                 return $errors;
1346         }
1347
1348         /**
1349          * Check various permission hooks
1350          *
1351          * @param $action String the action to check
1352          * @param $user User user to check
1353          * @param $errors Array list of current errors
1354          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1355          * @param $short Boolean short circuit on first error
1356          *
1357          * @return Array list of errors
1358          */
1359         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1360                 // Use getUserPermissionsErrors instead
1361                 $result = '';
1362                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1363                         return $result ? array() : array( array( 'badaccess-group0' ) );
1364                 }
1365                 // Check getUserPermissionsErrors hook
1366                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1367                         $errors = $this->resultToError( $errors, $result );
1368                 }
1369                 // Check getUserPermissionsErrorsExpensive hook
1370                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1371                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1372                         $errors = $this->resultToError( $errors, $result );
1373                 }
1374
1375                 return $errors;
1376         }
1377
1378         /**
1379          * Check permissions on special pages & namespaces
1380          *
1381          * @param $action String the action to check
1382          * @param $user User user to check
1383          * @param $errors Array list of current errors
1384          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1385          * @param $short Boolean short circuit on first error
1386          *
1387          * @return Array list of errors
1388          */
1389         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1390                 # Only 'createaccount' and 'execute' can be performed on
1391                 # special pages, which don't actually exist in the DB.
1392                 $specialOKActions = array( 'createaccount', 'execute' );
1393                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1394                         $errors[] = array( 'ns-specialprotected' );
1395                 }
1396
1397                 # Check $wgNamespaceProtection for restricted namespaces
1398                 if ( $this->isNamespaceProtected( $user ) ) {
1399                         $ns = $this->mNamespace == NS_MAIN ?
1400                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1401                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1402                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1403                 }
1404
1405                 return $errors;
1406         }
1407
1408         /**
1409          * Check CSS/JS sub-page permissions
1410          *
1411          * @param $action String the action to check
1412          * @param $user User user to check
1413          * @param $errors Array list of current errors
1414          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1415          * @param $short Boolean short circuit on first error
1416          *
1417          * @return Array list of errors
1418          */
1419         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1420                 # Protect css/js subpages of user pages
1421                 # XXX: this might be better using restrictions
1422                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1423                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1424                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1425                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1426                                 $errors[] = array( 'customcssprotected' );
1427                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1428                                 $errors[] = array( 'customjsprotected' );
1429                         }
1430                 }
1431
1432                 return $errors;
1433         }
1434
1435         /**
1436          * Check against page_restrictions table requirements on this
1437          * page. The user must possess all required rights for this
1438          * action.
1439          *
1440          * @param $action String the action to check
1441          * @param $user User user to check
1442          * @param $errors Array list of current errors
1443          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1444          * @param $short Boolean short circuit on first error
1445          *
1446          * @return Array list of errors
1447          */
1448         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1449                 foreach ( $this->getRestrictions( $action ) as $right ) {
1450                         // Backwards compatibility, rewrite sysop -> protect
1451                         if ( $right == 'sysop' ) {
1452                                 $right = 'protect';
1453                         }
1454                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1455                                 // Users with 'editprotected' permission can edit protected pages
1456                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected', $this->mNamespace ) ) {
1457                                         // Users with 'editprotected' permission cannot edit protected pages
1458                                         // with cascading option turned on.
1459                                         if ( $this->mCascadeRestriction ) {
1460                                                 $errors[] = array( 'protectedpagetext', $right );
1461                                         }
1462                                 } else {
1463                                         $errors[] = array( 'protectedpagetext', $right );
1464                                 }
1465                         }
1466                 }
1467
1468                 return $errors;
1469         }
1470
1471         /**
1472          * Check restrictions on cascading pages.
1473          *
1474          * @param $action String the action to check
1475          * @param $user User to check
1476          * @param $errors Array list of current errors
1477          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1478          * @param $short Boolean short circuit on first error
1479          *
1480          * @return Array list of errors
1481          */
1482         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1483                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1484                         # We /could/ use the protection level on the source page, but it's
1485                         # fairly ugly as we have to establish a precedence hierarchy for pages
1486                         # included by multiple cascade-protected pages. So just restrict
1487                         # it to people with 'protect' permission, as they could remove the
1488                         # protection anyway.
1489                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1490                         # Cascading protection depends on more than this page...
1491                         # Several cascading protected pages may include this page...
1492                         # Check each cascading level
1493                         # This is only for protection restrictions, not for all actions
1494                         if ( isset( $restrictions[$action] ) ) {
1495                                 foreach ( $restrictions[$action] as $right ) {
1496                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1497                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1498                                                 $pages = '';
1499                                                 foreach ( $cascadingSources as $page )
1500                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1501                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1502                                         }
1503                                 }
1504                         }
1505                 }
1506
1507                 return $errors;
1508         }
1509
1510         /**
1511          * Check action permissions not already checked in checkQuickPermissions
1512          *
1513          * @param $action String the action to check
1514          * @param $user User to check
1515          * @param $errors Array list of current errors
1516          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1517          * @param $short Boolean short circuit on first error
1518          *
1519          * @return Array list of errors
1520          */
1521         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1522                 if ( $action == 'protect' ) {
1523                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1524                                 // If they can't edit, they shouldn't protect.
1525                                 $errors[] = array( 'protect-cantedit' );
1526                         }
1527                 } elseif ( $action == 'create' ) {
1528                         $title_protection = $this->getTitleProtection();
1529                         if( $title_protection ) {
1530                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1531                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1532                                 }
1533                                 if( $title_protection['pt_create_perm'] == '' ||
1534                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1535                                                 $this->mNamespace ) ) {
1536                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1537                                 }
1538                         }
1539                 } elseif ( $action == 'move' ) {
1540                         // Check for immobile pages
1541                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1542                                 // Specific message for this case
1543                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1544                         } elseif ( !$this->isMovable() ) {
1545                                 // Less specific message for rarer cases
1546                                 $errors[] = array( 'immobile-page' );
1547                         }
1548                 } elseif ( $action == 'move-target' ) {
1549                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1550                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1551                         } elseif ( !$this->isMovable() ) {
1552                                 $errors[] = array( 'immobile-target-page' );
1553                         }
1554                 }
1555                 return $errors;
1556         }
1557
1558         /**
1559          * Check that the user isn't blocked from editting.
1560          *
1561          * @param $action String the action to check
1562          * @param $user User to check
1563          * @param $errors Array list of current errors
1564          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1565          * @param $short Boolean short circuit on first error
1566          *
1567          * @return Array list of errors
1568          */
1569         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1570                 if( !$doExpensiveQueries ) {
1571                         return $errors;
1572                 }
1573
1574                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1575
1576                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1577                         $errors[] = array( 'confirmedittext' );
1578                 }
1579
1580                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1581                         // Edit blocks should not affect reading.
1582                         // Account creation blocks handled at userlogin.
1583                         // Unblocking handled in SpecialUnblock
1584                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1585                         // Don't block the user from editing their own talk page unless they've been
1586                         // explicitly blocked from that too.
1587                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1588                         $block = $user->mBlock;
1589
1590                         // This is from OutputPage::blockedPage
1591                         // Copied at r23888 by werdna
1592
1593                         $id = $user->blockedBy();
1594                         $reason = $user->blockedFor();
1595                         if ( $reason == '' ) {
1596                                 $reason = wfMsg( 'blockednoreason' );
1597                         }
1598                         $ip = wfGetIP();
1599
1600                         if ( is_numeric( $id ) ) {
1601                                 $name = User::whoIs( $id );
1602                         } else {
1603                                 $name = $id;
1604                         }
1605
1606                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1607                         $blockid = $block->getId();
1608                         $blockExpiry = $user->mBlock->mExpiry;
1609                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1610                         if ( $blockExpiry == 'infinity' ) {
1611                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1612                         } else {
1613                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1614                         }
1615
1616                         $intended = strval( $user->mBlock->getTarget() );
1617
1618                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1619                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1620                 }
1621
1622                 return $errors;
1623         }
1624
1625         /**
1626          * Can $user perform $action on this page? This is an internal function,
1627          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1628          * checks on wfReadOnly() and blocks)
1629          *
1630          * @param $action String action that permission needs to be checked for
1631          * @param $user User to check
1632          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1633          * @param $short Bool Set this to true to stop after the first permission error.
1634          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1635          */
1636         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1637                 wfProfileIn( __METHOD__ );
1638
1639                 $errors = array();
1640                 $checks = array(
1641                         'checkQuickPermissions',
1642                         'checkPermissionHooks',
1643                         'checkSpecialsAndNSPermissions',
1644                         'checkCSSandJSPermissions',
1645                         'checkPageRestrictions',
1646                         'checkCascadingSourcesRestrictions',
1647                         'checkActionPermissions',
1648                         'checkUserBlock'
1649                 );
1650
1651                 while( count( $checks ) > 0 &&
1652                            !( $short && count( $errors ) > 0 ) ) {
1653                         $method = array_shift( $checks );
1654                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1655                 }
1656
1657                 wfProfileOut( __METHOD__ );
1658                 return $errors;
1659         }
1660
1661         /**
1662          * Is this title subject to title protection?
1663          * Title protection is the one applied against creation of such title.
1664          *
1665          * @return Mixed An associative array representing any existent title
1666          *   protection, or false if there's none.
1667          */
1668         private function getTitleProtection() {
1669                 // Can't protect pages in special namespaces
1670                 if ( $this->getNamespace() < 0 ) {
1671                         return false;
1672                 }
1673
1674                 // Can't protect pages that exist.
1675                 if ( $this->exists() ) {
1676                         return false;
1677                 }
1678
1679                 if ( !isset( $this->mTitleProtection ) ) {
1680                         $dbr = wfGetDB( DB_SLAVE );
1681                         $res = $dbr->select( 'protected_titles', '*',
1682                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1683                                 __METHOD__ );
1684
1685                         // fetchRow returns false if there are no rows.
1686                         $this->mTitleProtection = $dbr->fetchRow( $res );
1687                 }
1688                 return $this->mTitleProtection;
1689         }
1690
1691         /**
1692          * Update the title protection status
1693          *
1694          * @param $create_perm String Permission required for creation
1695          * @param $reason String Reason for protection
1696          * @param $expiry String Expiry timestamp
1697          * @return boolean true
1698          */
1699         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1700                 global $wgUser, $wgContLang;
1701
1702                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1703                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1704                         // No change
1705                         return true;
1706                 }
1707
1708                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1709
1710                 $dbw = wfGetDB( DB_MASTER );
1711
1712                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1713
1714                 $expiry_description = '';
1715                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1716                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1717                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1718                 } else {
1719                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1720                 }
1721
1722                 # Update protection table
1723                 if ( $create_perm != '' ) {
1724                         $this->mTitleProtection = array(
1725                                         'pt_namespace' => $namespace,
1726                                         'pt_title' => $title,
1727                                         'pt_create_perm' => $create_perm,
1728                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1729                                         'pt_expiry' => $encodedExpiry,
1730                                         'pt_user' => $wgUser->getId(),
1731                                         'pt_reason' => $reason,
1732                                 );
1733                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1734                                 $this->mTitleProtection, __METHOD__     );
1735                 } else {
1736                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1737                                 'pt_title' => $title ), __METHOD__ );
1738                         $this->mTitleProtection = false;
1739                 }
1740
1741                 # Update the protection log
1742                 if ( $dbw->affectedRows() ) {
1743                         $log = new LogPage( 'protect' );
1744
1745                         if ( $create_perm ) {
1746                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1747                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1748                         } else {
1749                                 $log->addEntry( 'unprotect', $this, $reason );
1750                         }
1751                 }
1752
1753                 return true;
1754         }
1755
1756         /**
1757          * Remove any title protection due to page existing
1758          */
1759         public function deleteTitleProtection() {
1760                 $dbw = wfGetDB( DB_MASTER );
1761
1762                 $dbw->delete(
1763                         'protected_titles',
1764                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1765                         __METHOD__
1766                 );
1767                 $this->mTitleProtection = false;
1768         }
1769
1770         /**
1771          * Would anybody with sufficient privileges be able to move this page?
1772          * Some pages just aren't movable.
1773          *
1774          * @return Bool TRUE or FALSE
1775          */
1776         public function isMovable() {
1777                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1778         }
1779
1780         /**
1781          * Can $wgUser read this page?
1782          *
1783          * @return Bool
1784          * @todo fold these checks into userCan()
1785          */
1786         public function userCanRead() {
1787                 global $wgUser, $wgGroupPermissions;
1788
1789                 static $useShortcut = null;
1790
1791                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1792                 if ( is_null( $useShortcut ) ) {
1793                         global $wgRevokePermissions;
1794                         $useShortcut = true;
1795                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1796                                 # Not a public wiki, so no shortcut
1797                                 $useShortcut = false;
1798                         } elseif ( !empty( $wgRevokePermissions ) ) {
1799                                 /**
1800                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1801                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1802                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1803                                  * reading is allowed.
1804                                  */
1805                                 foreach ( $wgRevokePermissions as $perms ) {
1806                                         if ( !empty( $perms['read'] ) ) {
1807                                                 # We might be removing the read right from the user, so no shortcut
1808                                                 $useShortcut = false;
1809                                                 break;
1810                                         }
1811                                 }
1812                         }
1813                 }
1814
1815                 $result = null;
1816                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1817                 if ( $result !== null ) {
1818                         return $result;
1819                 }
1820
1821                 # Shortcut for public wikis, allows skipping quite a bit of code
1822                 if ( $useShortcut ) {
1823                         return true;
1824                 }
1825
1826                 if ( $wgUser->isAllowed( 'read' ) ) {
1827                         return true;
1828                 } else {
1829                         global $wgWhitelistRead;
1830
1831                         # Always grant access to the login page.
1832                         # Even anons need to be able to log in.
1833                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1834                                 return true;
1835                         }
1836
1837                         # Bail out if there isn't whitelist
1838                         if ( !is_array( $wgWhitelistRead ) ) {
1839                                 return false;
1840                         }
1841
1842                         # Check for explicit whitelisting
1843                         $name = $this->getPrefixedText();
1844                         $dbName = $this->getPrefixedDBKey();
1845                         // Check with and without underscores
1846                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1847                                 return true;
1848
1849                         # Old settings might have the title prefixed with
1850                         # a colon for main-namespace pages
1851                         if ( $this->getNamespace() == NS_MAIN ) {
1852                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1853                                         return true;
1854                                 }
1855                         }
1856
1857                         # If it's a special page, ditch the subpage bit and check again
1858                         if ( $this->getNamespace() == NS_SPECIAL ) {
1859                                 $name = $this->getDBkey();
1860                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1861                                 if ( $name === false ) {
1862                                         # Invalid special page, but we show standard login required message
1863                                         return false;
1864                                 }
1865
1866                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1867                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1868                                         return true;
1869                                 }
1870                         }
1871
1872                 }
1873                 return false;
1874         }
1875
1876         /**
1877          * Is this the mainpage?
1878          * @note Title::newFromText seams to be sufficiently optimized by the title
1879          * cache that we don't need to over-optimize by doing direct comparisons and
1880          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1881          * ends up reporting something differently than $title->isMainPage();
1882          *
1883          * @return Bool
1884          */
1885         public function isMainPage() {
1886                 return $this->equals( Title::newMainPage() );
1887         }
1888
1889         /**
1890          * Is this a talk page of some sort?
1891          *
1892          * @return Bool
1893          */
1894         public function isTalkPage() {
1895                 return MWNamespace::isTalk( $this->getNamespace() );
1896         }
1897
1898         /**
1899          * Is this a subpage?
1900          *
1901          * @return Bool
1902          */
1903         public function isSubpage() {
1904                 return MWNamespace::hasSubpages( $this->mNamespace )
1905                         ? strpos( $this->getText(), '/' ) !== false
1906                         : false;
1907         }
1908
1909         /**
1910          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1911          *
1912          * @return Bool
1913          */
1914         public function hasSubpages() {
1915                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1916                         # Duh
1917                         return false;
1918                 }
1919
1920                 # We dynamically add a member variable for the purpose of this method
1921                 # alone to cache the result.  There's no point in having it hanging
1922                 # around uninitialized in every Title object; therefore we only add it
1923                 # if needed and don't declare it statically.
1924                 if ( isset( $this->mHasSubpages ) ) {
1925                         return $this->mHasSubpages;
1926                 }
1927
1928                 $subpages = $this->getSubpages( 1 );
1929                 if ( $subpages instanceof TitleArray ) {
1930                         return $this->mHasSubpages = (bool)$subpages->count();
1931                 }
1932                 return $this->mHasSubpages = false;
1933         }
1934
1935         /**
1936          * Get all subpages of this page.
1937          *
1938          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1939          * @return mixed TitleArray, or empty array if this page's namespace
1940          *  doesn't allow subpages
1941          */
1942         public function getSubpages( $limit = -1 ) {
1943                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1944                         return array();
1945                 }
1946
1947                 $dbr = wfGetDB( DB_SLAVE );
1948                 $conds['page_namespace'] = $this->getNamespace();
1949                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1950                 $options = array();
1951                 if ( $limit > -1 ) {
1952                         $options['LIMIT'] = $limit;
1953                 }
1954                 return $this->mSubpages = TitleArray::newFromResult(
1955                         $dbr->select( 'page',
1956                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1957                                 $conds,
1958                                 __METHOD__,
1959                                 $options
1960                         )
1961                 );
1962         }
1963
1964         /**
1965          * Could this page contain custom CSS or JavaScript, based
1966          * on the title?
1967          *
1968          * @return Bool
1969          */
1970         public function isCssOrJsPage() {
1971                 return $this->mNamespace == NS_MEDIAWIKI
1972                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1973         }
1974
1975         /**
1976          * Is this a .css or .js subpage of a user page?
1977          * @return Bool
1978          */
1979         public function isCssJsSubpage() {
1980                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1981         }
1982
1983         /**
1984          * Is this a *valid* .css or .js subpage of a user page?
1985          *
1986          * @return Bool
1987          * @deprecated since 1.17
1988          */
1989         public function isValidCssJsSubpage() {
1990                 return $this->isCssJsSubpage();
1991         }
1992
1993         /**
1994          * Trim down a .css or .js subpage title to get the corresponding skin name
1995          *
1996          * @return string containing skin name from .css or .js subpage title
1997          */
1998         public function getSkinFromCssJsSubpage() {
1999                 $subpage = explode( '/', $this->mTextform );
2000                 $subpage = $subpage[ count( $subpage ) - 1 ];
2001                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
2002         }
2003
2004         /**
2005          * Is this a .css subpage of a user page?
2006          *
2007          * @return Bool
2008          */
2009         public function isCssSubpage() {
2010                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2011         }
2012
2013         /**
2014          * Is this a .js subpage of a user page?
2015          *
2016          * @return Bool
2017          */
2018         public function isJsSubpage() {
2019                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2020         }
2021
2022         /**
2023          * Protect css subpages of user pages: can $wgUser edit
2024          * this page?
2025          *
2026          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2027          * @return Bool
2028          */
2029         public function userCanEditCssSubpage() {
2030                 global $wgUser;
2031                 wfDeprecated( __METHOD__ );
2032                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2033                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2034         }
2035
2036         /**
2037          * Protect js subpages of user pages: can $wgUser edit
2038          * this page?
2039          *
2040          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2041          * @return Bool
2042          */
2043         public function userCanEditJsSubpage() {
2044                 global $wgUser;
2045                 wfDeprecated( __METHOD__ );
2046                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2047                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2048         }
2049
2050         /**
2051          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2052          *
2053          * @return Bool If the page is subject to cascading restrictions.
2054          */
2055         public function isCascadeProtected() {
2056                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2057                 return ( $sources > 0 );
2058         }
2059
2060         /**
2061          * Cascading protection: Get the source of any cascading restrictions on this page.
2062          *
2063          * @param $getPages Bool Whether or not to retrieve the actual pages
2064          *        that the restrictions have come from.
2065          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2066          *     have come, false for none, or true if such restrictions exist, but $getPages
2067          *     was not set.  The restriction array is an array of each type, each of which
2068          *     contains a array of unique groups.
2069          */
2070         public function getCascadeProtectionSources( $getPages = true ) {
2071                 global $wgContLang;
2072                 $pagerestrictions = array();
2073
2074                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2075                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2076                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2077                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2078                 }
2079
2080                 wfProfileIn( __METHOD__ );
2081
2082                 $dbr = wfGetDB( DB_SLAVE );
2083
2084                 if ( $this->getNamespace() == NS_FILE ) {
2085                         $tables = array( 'imagelinks', 'page_restrictions' );
2086                         $where_clauses = array(
2087                                 'il_to' => $this->getDBkey(),
2088                                 'il_from=pr_page',
2089                                 'pr_cascade' => 1
2090                         );
2091                 } else {
2092                         $tables = array( 'templatelinks', 'page_restrictions' );
2093                         $where_clauses = array(
2094                                 'tl_namespace' => $this->getNamespace(),
2095                                 'tl_title' => $this->getDBkey(),
2096                                 'tl_from=pr_page',
2097                                 'pr_cascade' => 1
2098                         );
2099                 }
2100
2101                 if ( $getPages ) {
2102                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2103                                                    'pr_expiry', 'pr_type', 'pr_level' );
2104                         $where_clauses[] = 'page_id=pr_page';
2105                         $tables[] = 'page';
2106                 } else {
2107                         $cols = array( 'pr_expiry' );
2108                 }
2109
2110                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2111
2112                 $sources = $getPages ? array() : false;
2113                 $now = wfTimestampNow();
2114                 $purgeExpired = false;
2115
2116                 foreach ( $res as $row ) {
2117                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2118                         if ( $expiry > $now ) {
2119                                 if ( $getPages ) {
2120                                         $page_id = $row->pr_page;
2121                                         $page_ns = $row->page_namespace;
2122                                         $page_title = $row->page_title;
2123                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2124                                         # Add groups needed for each restriction type if its not already there
2125                                         # Make sure this restriction type still exists
2126
2127                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2128                                                 $pagerestrictions[$row->pr_type] = array();
2129                                         }
2130
2131                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2132                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2133                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2134                                         }
2135                                 } else {
2136                                         $sources = true;
2137                                 }
2138                         } else {
2139                                 // Trigger lazy purge of expired restrictions from the db
2140                                 $purgeExpired = true;
2141                         }
2142                 }
2143                 if ( $purgeExpired ) {
2144                         Title::purgeExpiredRestrictions();
2145                 }
2146
2147                 if ( $getPages ) {
2148                         $this->mCascadeSources = $sources;
2149                         $this->mCascadingRestrictions = $pagerestrictions;
2150                 } else {
2151                         $this->mHasCascadingRestrictions = $sources;
2152                 }
2153
2154                 wfProfileOut( __METHOD__ );
2155                 return array( $sources, $pagerestrictions );
2156         }
2157
2158         /**
2159          * Returns cascading restrictions for the current article
2160          *
2161          * @return Boolean
2162          */
2163         function areRestrictionsCascading() {
2164                 if ( !$this->mRestrictionsLoaded ) {
2165                         $this->loadRestrictions();
2166                 }
2167
2168                 return $this->mCascadeRestriction;
2169         }
2170
2171         /**
2172          * Loads a string into mRestrictions array
2173          *
2174          * @param $res Resource restrictions as an SQL result.
2175          * @param $oldFashionedRestrictions String comma-separated list of page
2176          *        restrictions from page table (pre 1.10)
2177          */
2178         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2179                 $rows = array();
2180
2181                 foreach ( $res as $row ) {
2182                         $rows[] = $row;
2183                 }
2184
2185                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2186         }
2187
2188         /**
2189          * Compiles list of active page restrictions from both page table (pre 1.10)
2190          * and page_restrictions table for this existing page.
2191          * Public for usage by LiquidThreads.
2192          *
2193          * @param $rows array of db result objects
2194          * @param $oldFashionedRestrictions string comma-separated list of page
2195          *        restrictions from page table (pre 1.10)
2196          */
2197         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2198                 global $wgContLang;
2199                 $dbr = wfGetDB( DB_SLAVE );
2200
2201                 $restrictionTypes = $this->getRestrictionTypes();
2202
2203                 foreach ( $restrictionTypes as $type ) {
2204                         $this->mRestrictions[$type] = array();
2205                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2206                 }
2207
2208                 $this->mCascadeRestriction = false;
2209
2210                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2211
2212                 if ( $oldFashionedRestrictions === null ) {
2213                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2214                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2215                 }
2216
2217                 if ( $oldFashionedRestrictions != '' ) {
2218
2219                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2220                                 $temp = explode( '=', trim( $restrict ) );
2221                                 if ( count( $temp ) == 1 ) {
2222                                         // old old format should be treated as edit/move restriction
2223                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2224                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2225                                 } else {
2226                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2227                                 }
2228                         }
2229
2230                         $this->mOldRestrictions = true;
2231
2232                 }
2233
2234                 if ( count( $rows ) ) {
2235                         # Current system - load second to make them override.
2236                         $now = wfTimestampNow();
2237                         $purgeExpired = false;
2238
2239                         # Cycle through all the restrictions.
2240                         foreach ( $rows as $row ) {
2241
2242                                 // Don't take care of restrictions types that aren't allowed
2243                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2244                                         continue;
2245
2246                                 // This code should be refactored, now that it's being used more generally,
2247                                 // But I don't really see any harm in leaving it in Block for now -werdna
2248                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2249
2250                                 // Only apply the restrictions if they haven't expired!
2251                                 if ( !$expiry || $expiry > $now ) {
2252                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2253                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2254
2255                                         $this->mCascadeRestriction |= $row->pr_cascade;
2256                                 } else {
2257                                         // Trigger a lazy purge of expired restrictions
2258                                         $purgeExpired = true;
2259                                 }
2260                         }
2261
2262                         if ( $purgeExpired ) {
2263                                 Title::purgeExpiredRestrictions();
2264                         }
2265                 }
2266
2267                 $this->mRestrictionsLoaded = true;
2268         }
2269
2270         /**
2271          * Load restrictions from the page_restrictions table
2272          *
2273          * @param $oldFashionedRestrictions String comma-separated list of page
2274          *        restrictions from page table (pre 1.10)
2275          */
2276         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2277                 global $wgContLang;
2278                 if ( !$this->mRestrictionsLoaded ) {
2279                         if ( $this->exists() ) {
2280                                 $dbr = wfGetDB( DB_SLAVE );
2281
2282                                 $res = $dbr->select(
2283                                         'page_restrictions',
2284                                         '*',
2285                                         array( 'pr_page' => $this->getArticleId() ),
2286                                         __METHOD__
2287                                 );
2288
2289                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2290                         } else {
2291                                 $title_protection = $this->getTitleProtection();
2292
2293                                 if ( $title_protection ) {
2294                                         $now = wfTimestampNow();
2295                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2296
2297                                         if ( !$expiry || $expiry > $now ) {
2298                                                 // Apply the restrictions
2299                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2300                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2301                                         } else { // Get rid of the old restrictions
2302                                                 Title::purgeExpiredRestrictions();
2303                                                 $this->mTitleProtection = false;
2304                                         }
2305                                 } else {
2306                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2307                                 }
2308                                 $this->mRestrictionsLoaded = true;
2309                         }
2310                 }
2311         }
2312
2313         /**
2314          * Purge expired restrictions from the page_restrictions table
2315          */
2316         static function purgeExpiredRestrictions() {
2317                 $dbw = wfGetDB( DB_MASTER );
2318                 $dbw->delete(
2319                         'page_restrictions',
2320                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2321                         __METHOD__
2322                 );
2323
2324                 $dbw->delete(
2325                         'protected_titles',
2326                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2327                         __METHOD__
2328                 );
2329         }
2330
2331         /**
2332          * Accessor/initialisation for mRestrictions
2333          *
2334          * @param $action String action that permission needs to be checked for
2335          * @return Array of Strings the array of groups allowed to edit this article
2336          */
2337         public function getRestrictions( $action ) {
2338                 if ( !$this->mRestrictionsLoaded ) {
2339                         $this->loadRestrictions();
2340                 }
2341                 return isset( $this->mRestrictions[$action] )
2342                                 ? $this->mRestrictions[$action]
2343                                 : array();
2344         }
2345
2346         /**
2347          * Get the expiry time for the restriction against a given action
2348          *
2349          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2350          *      or not protected at all, or false if the action is not recognised.
2351          */
2352         public function getRestrictionExpiry( $action ) {
2353                 if ( !$this->mRestrictionsLoaded ) {
2354                         $this->loadRestrictions();
2355                 }
2356                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2357         }
2358
2359         /**
2360          * Is there a version of this page in the deletion archive?
2361          *
2362          * @param $includeSuppressed Boolean Include suppressed revisions?
2363          * @return Int the number of archived revisions
2364          */
2365         public function isDeleted( $includeSuppressed = false ) {
2366                 if ( $this->getNamespace() < 0 ) {
2367                         $n = 0;
2368                 } else {
2369                         $dbr = wfGetDB( DB_SLAVE );
2370                         $conditions = array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() );
2371
2372                         if( !$includeSuppressed ) {
2373                                 $suppressedTextBits = Revision::DELETED_TEXT | Revision::DELETED_RESTRICTED;
2374                                 $conditions[] = $dbr->bitAnd('ar_deleted', $suppressedTextBits ) .
2375                                 ' != ' . $suppressedTextBits;
2376                         }
2377
2378                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2379                                 $conditions,
2380                                 __METHOD__
2381                         );
2382                         if ( $this->getNamespace() == NS_FILE ) {
2383                                 $fconditions = array( 'fa_name' => $this->getDBkey() );
2384                                 if( !$includeSuppressed ) {
2385                                         $suppressedTextBits = File::DELETED_FILE | File::DELETED_RESTRICTED;
2386                                         $fconditions[] = $dbr->bitAnd('fa_deleted', $suppressedTextBits ) .
2387                                         ' != ' . $suppressedTextBits;
2388                                 }
2389
2390                                 $n += $dbr->selectField( 'filearchive',
2391                                         'COUNT(*)',
2392                                         $fconditions,
2393                                         __METHOD__
2394                                 );
2395                         }
2396                 }
2397                 return (int)$n;
2398         }
2399
2400         /**
2401          * Is there a version of this page in the deletion archive?
2402          *
2403          * @return Boolean
2404          */
2405         public function isDeletedQuick() {
2406                 if ( $this->getNamespace() < 0 ) {
2407                         return false;
2408                 }
2409                 $dbr = wfGetDB( DB_SLAVE );
2410                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2411                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2412                         __METHOD__
2413                 );
2414                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2415                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2416                                 array( 'fa_name' => $this->getDBkey() ),
2417                                 __METHOD__
2418                         );
2419                 }
2420                 return $deleted;
2421         }
2422
2423         /**
2424          * Get the article ID for this Title from the link cache,
2425          * adding it if necessary
2426          *
2427          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2428          *  for update
2429          * @return Int the ID
2430          */
2431         public function getArticleID( $flags = 0 ) {
2432                 if ( $this->getNamespace() < 0 ) {
2433                         return $this->mArticleID = 0;
2434                 }
2435                 $linkCache = LinkCache::singleton();
2436                 if ( $flags & self::GAID_FOR_UPDATE ) {
2437                         $oldUpdate = $linkCache->forUpdate( true );
2438                         $linkCache->clearLink( $this );
2439                         $this->mArticleID = $linkCache->addLinkObj( $this );
2440                         $linkCache->forUpdate( $oldUpdate );
2441                 } else {
2442                         if ( -1 == $this->mArticleID ) {
2443                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2444                         }
2445                 }
2446                 return $this->mArticleID;
2447         }
2448
2449         /**
2450          * Is this an article that is a redirect page?
2451          * Uses link cache, adding it if necessary
2452          *
2453          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2454          * @return Bool
2455          */
2456         public function isRedirect( $flags = 0 ) {
2457                 if ( !is_null( $this->mRedirect ) ) {
2458                         return $this->mRedirect;
2459                 }
2460                 # Calling getArticleID() loads the field from cache as needed
2461                 if ( !$this->getArticleID( $flags ) ) {
2462                         return $this->mRedirect = false;
2463                 }
2464                 $linkCache = LinkCache::singleton();
2465                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2466
2467                 return $this->mRedirect;
2468         }
2469
2470         /**
2471          * What is the length of this page?
2472          * Uses link cache, adding it if necessary
2473          *
2474          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2475          * @return Int
2476          */
2477         public function getLength( $flags = 0 ) {
2478                 if ( $this->mLength != -1 ) {
2479                         return $this->mLength;
2480                 }
2481                 # Calling getArticleID() loads the field from cache as needed
2482                 if ( !$this->getArticleID( $flags ) ) {
2483                         return $this->mLength = 0;
2484                 }
2485                 $linkCache = LinkCache::singleton();
2486                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2487
2488                 return $this->mLength;
2489         }
2490
2491         /**
2492          * What is the page_latest field for this page?
2493          *
2494          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2495          * @return Int or 0 if the page doesn't exist
2496          */
2497         public function getLatestRevID( $flags = 0 ) {
2498                 if ( $this->mLatestID !== false ) {
2499                         return intval( $this->mLatestID );
2500                 }
2501                 # Calling getArticleID() loads the field from cache as needed
2502                 if ( !$this->getArticleID( $flags ) ) {
2503                         return $this->mLatestID = 0;
2504                 }
2505                 $linkCache = LinkCache::singleton();
2506                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2507
2508                 return $this->mLatestID;
2509         }
2510
2511         /**
2512          * This clears some fields in this object, and clears any associated
2513          * keys in the "bad links" section of the link cache.
2514          *
2515          * - This is called from Article::doEdit() and Article::insertOn() to allow
2516          * loading of the new page_id. It's also called from
2517          * Article::doDeleteArticle()
2518          *
2519          * @param $newid Int the new Article ID
2520          */
2521         public function resetArticleID( $newid ) {
2522                 $linkCache = LinkCache::singleton();
2523                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2524
2525                 if ( $newid === false ) {
2526                         $this->mArticleID = -1;
2527                 } else {
2528                         $this->mArticleID = intval( $newid );
2529                 }
2530                 $this->mRestrictionsLoaded = false;
2531                 $this->mRestrictions = array();
2532                 $this->mRedirect = null;
2533                 $this->mLength = -1;
2534                 $this->mLatestID = false;
2535         }
2536
2537         /**
2538          * Updates page_touched for this page; called from LinksUpdate.php
2539          *
2540          * @return Bool true if the update succeded
2541          */
2542         public function invalidateCache() {
2543                 if ( wfReadOnly() ) {
2544                         return;
2545                 }
2546                 $dbw = wfGetDB( DB_MASTER );
2547                 $success = $dbw->update(
2548                         'page',
2549                         array( 'page_touched' => $dbw->timestamp() ),
2550                         $this->pageCond(),
2551                         __METHOD__
2552                 );
2553                 HTMLFileCache::clearFileCache( $this );
2554                 return $success;
2555         }
2556
2557         /**
2558          * Prefix some arbitrary text with the namespace or interwiki prefix
2559          * of this object
2560          *
2561          * @param $name String the text
2562          * @return String the prefixed text
2563          * @private
2564          */
2565         private function prefix( $name ) {
2566                 $p = '';
2567                 if ( $this->mInterwiki != '' ) {
2568                         $p = $this->mInterwiki . ':';
2569                 }
2570
2571                 if ( 0 != $this->mNamespace ) {
2572                         $p .= $this->getNsText() . ':';
2573                 }
2574                 return $p . $name;
2575         }
2576
2577         /**
2578          * Returns a simple regex that will match on characters and sequences invalid in titles.
2579          * Note that this doesn't pick up many things that could be wrong with titles, but that
2580          * replacing this regex with something valid will make many titles valid.
2581          *
2582          * @return String regex string
2583          */
2584         static function getTitleInvalidRegex() {
2585                 static $rxTc = false;
2586                 if ( !$rxTc ) {
2587                         # Matching titles will be held as illegal.
2588                         $rxTc = '/' .
2589                                 # Any character not allowed is forbidden...
2590                                 '[^' . Title::legalChars() . ']' .
2591                                 # URL percent encoding sequences interfere with the ability
2592                                 # to round-trip titles -- you can't link to them consistently.
2593                                 '|%[0-9A-Fa-f]{2}' .
2594                                 # XML/HTML character references produce similar issues.
2595                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2596                                 '|&#[0-9]+;' .
2597                                 '|&#x[0-9A-Fa-f]+;' .
2598                                 '/S';
2599                 }
2600
2601                 return $rxTc;
2602         }
2603
2604         /**
2605          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2606          *
2607          * @param $text String containing title to capitalize
2608          * @param $ns int namespace index, defaults to NS_MAIN
2609          * @return String containing capitalized title
2610          */
2611         public static function capitalize( $text, $ns = NS_MAIN ) {
2612                 global $wgContLang;
2613
2614                 if ( MWNamespace::isCapitalized( $ns ) ) {
2615                         return $wgContLang->ucfirst( $text );
2616                 } else {
2617                         return $text;
2618                 }
2619         }
2620
2621         /**
2622          * Secure and split - main initialisation function for this object
2623          *
2624          * Assumes that mDbkeyform has been set, and is urldecoded
2625          * and uses underscores, but not otherwise munged.  This function
2626          * removes illegal characters, splits off the interwiki and
2627          * namespace prefixes, sets the other forms, and canonicalizes
2628          * everything.
2629          *
2630          * @return Bool true on success
2631          */
2632         private function secureAndSplit() {
2633                 global $wgContLang, $wgLocalInterwiki;
2634
2635                 # Initialisation
2636                 $this->mInterwiki = $this->mFragment = '';
2637                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2638
2639                 $dbkey = $this->mDbkeyform;
2640
2641                 # Strip Unicode bidi override characters.
2642                 # Sometimes they slip into cut-n-pasted page titles, where the
2643                 # override chars get included in list displays.
2644                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2645
2646                 # Clean up whitespace
2647                 # Note: use of the /u option on preg_replace here will cause
2648                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2649                 # conveniently disabling them.
2650                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2651                 $dbkey = trim( $dbkey, '_' );
2652
2653                 if ( $dbkey == '' ) {
2654                         return false;
2655                 }
2656
2657                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2658                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2659                         return false;
2660                 }
2661
2662                 $this->mDbkeyform = $dbkey;
2663
2664                 # Initial colon indicates main namespace rather than specified default
2665                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2666                 if ( ':' == $dbkey[0] ) {
2667                         $this->mNamespace = NS_MAIN;
2668                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2669                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2670                 }
2671
2672                 # Namespace or interwiki prefix
2673                 $firstPass = true;
2674                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2675                 do {
2676                         $m = array();
2677                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2678                                 $p = $m[1];
2679                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2680                                         # Ordinary namespace
2681                                         $dbkey = $m[2];
2682                                         $this->mNamespace = $ns;
2683                                         # For Talk:X pages, check if X has a "namespace" prefix
2684                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2685                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2686                                                         # Disallow Talk:File:x type titles...
2687                                                         return false;
2688                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2689                                                         # Disallow Talk:Interwiki:x type titles...
2690                                                         return false;
2691                                                 }
2692                                         }
2693                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2694                                         if ( !$firstPass ) {
2695                                                 # Can't make a local interwiki link to an interwiki link.
2696                                                 # That's just crazy!
2697                                                 return false;
2698                                         }
2699
2700                                         # Interwiki link
2701                                         $dbkey = $m[2];
2702                                         $this->mInterwiki = $wgContLang->lc( $p );
2703
2704                                         # Redundant interwiki prefix to the local wiki
2705                                         if ( $wgLocalInterwiki !== false
2706                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2707                                         {
2708                                                 if ( $dbkey == '' ) {
2709                                                         # Can't have an empty self-link
2710                                                         return false;
2711                                                 }
2712                                                 $this->mInterwiki = '';
2713                                                 $firstPass = false;
2714                                                 # Do another namespace split...
2715                                                 continue;
2716                                         }
2717
2718                                         # If there's an initial colon after the interwiki, that also
2719                                         # resets the default namespace
2720                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2721                                                 $this->mNamespace = NS_MAIN;
2722                                                 $dbkey = substr( $dbkey, 1 );
2723                                         }
2724                                 }
2725                                 # If there's no recognized interwiki or namespace,
2726                                 # then let the colon expression be part of the title.
2727                         }
2728                         break;
2729                 } while ( true );
2730
2731                 # We already know that some pages won't be in the database!
2732                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2733                         $this->mArticleID = 0;
2734                 }
2735                 $fragment = strstr( $dbkey, '#' );
2736                 if ( false !== $fragment ) {
2737                         $this->setFragment( $fragment );
2738                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2739                         # remove whitespace again: prevents "Foo_bar_#"
2740                         # becoming "Foo_bar_"
2741                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2742                 }
2743
2744                 # Reject illegal characters.
2745                 $rxTc = self::getTitleInvalidRegex();
2746                 if ( preg_match( $rxTc, $dbkey ) ) {
2747                         return false;
2748                 }
2749
2750                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2751                 # reachable due to the way web browsers deal with 'relative' URLs.
2752                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2753                 if ( strpos( $dbkey, '.' ) !== false &&
2754                          ( $dbkey === '.' || $dbkey === '..' ||
2755                            strpos( $dbkey, './' ) === 0  ||
2756                            strpos( $dbkey, '../' ) === 0 ||
2757                            strpos( $dbkey, '/./' ) !== false ||
2758                            strpos( $dbkey, '/../' ) !== false  ||
2759                            substr( $dbkey, -2 ) == '/.' ||
2760                            substr( $dbkey, -3 ) == '/..' ) )
2761                 {
2762                         return false;
2763                 }
2764
2765                 # Magic tilde sequences? Nu-uh!
2766                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2767                         return false;
2768                 }
2769
2770                 # Limit the size of titles to 255 bytes. This is typically the size of the
2771                 # underlying database field. We make an exception for special pages, which
2772                 # don't need to be stored in the database, and may edge over 255 bytes due
2773                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2774                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2775                   strlen( $dbkey ) > 512 )
2776                 {
2777                         return false;
2778                 }
2779
2780                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2781                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2782                 # other site might be case-sensitive.
2783                 $this->mUserCaseDBKey = $dbkey;
2784                 if ( $this->mInterwiki == '' ) {
2785                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2786                 }
2787
2788                 # Can't make a link to a namespace alone... "empty" local links can only be
2789                 # self-links with a fragment identifier.
2790                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2791                         return false;
2792                 }
2793
2794                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2795                 // IP names are not allowed for accounts, and can only be referring to
2796                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2797                 // there are numerous ways to present the same IP. Having sp:contribs scan
2798                 // them all is silly and having some show the edits and others not is
2799                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2800                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2801                         ? IP::sanitizeIP( $dbkey )
2802                         : $dbkey;
2803
2804                 // Any remaining initial :s are illegal.
2805                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2806                         return false;
2807                 }
2808
2809                 # Fill fields
2810                 $this->mDbkeyform = $dbkey;
2811                 $this->mUrlform = wfUrlencode( $dbkey );
2812
2813                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2814
2815                 return true;
2816         }
2817
2818         /**
2819          * Set the fragment for this title. Removes the first character from the
2820          * specified fragment before setting, so it assumes you're passing it with
2821          * an initial "#".
2822          *
2823          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2824          * Still in active use privately.
2825          *
2826          * @param $fragment String text
2827          */
2828         public function setFragment( $fragment ) {
2829                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2830         }
2831
2832         public function setInterwiki( $interwiki ) {
2833                 $this->mInterwiki = $interwiki;
2834         }
2835
2836         /**
2837          * Get a Title object associated with the talk page of this article
2838          *
2839          * @return Title the object for the talk page
2840          */
2841         public function getTalkPage() {
2842                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2843         }
2844
2845         /**
2846          * Get a title object associated with the subject page of this
2847          * talk page
2848          *
2849          * @return Title the object for the subject page
2850          */
2851         public function getSubjectPage() {
2852                 // Is this the same title?
2853                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2854                 if ( $this->getNamespace() == $subjectNS ) {
2855                         return $this;
2856                 }
2857                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2858         }
2859
2860         /**
2861          * Get an array of Title objects linking to this Title
2862          * Also stores the IDs in the link cache.
2863          *
2864          * WARNING: do not use this function on arbitrary user-supplied titles!
2865          * On heavily-used templates it will max out the memory.
2866          *
2867          * @param $options Array: may be FOR UPDATE
2868          * @param $table String: table name
2869          * @param $prefix String: fields prefix
2870          * @return Array of Title objects linking here
2871          */
2872         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2873                 $linkCache = LinkCache::singleton();
2874
2875                 if ( count( $options ) > 0 ) {
2876                         $db = wfGetDB( DB_MASTER );
2877                 } else {
2878                         $db = wfGetDB( DB_SLAVE );
2879                 }
2880
2881                 $res = $db->select(
2882                         array( 'page', $table ),
2883                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2884                         array(
2885                                 "{$prefix}_from=page_id",
2886                                 "{$prefix}_namespace" => $this->getNamespace(),
2887                                 "{$prefix}_title"     => $this->getDBkey() ),
2888                         __METHOD__,
2889                         $options
2890                 );
2891
2892                 $retVal = array();
2893                 if ( $db->numRows( $res ) ) {
2894                         foreach ( $res as $row ) {
2895                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2896                                 if ( $titleObj ) {
2897                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2898                                         $retVal[] = $titleObj;
2899                                 }
2900                         }
2901                 }
2902                 return $retVal;
2903         }
2904
2905         /**
2906          * Get an array of Title objects using this Title as a template
2907          * Also stores the IDs in the link cache.
2908          *
2909          * WARNING: do not use this function on arbitrary user-supplied titles!
2910          * On heavily-used templates it will max out the memory.
2911          *
2912          * @param $options Array: may be FOR UPDATE
2913          * @return Array of Title the Title objects linking here
2914          */
2915         public function getTemplateLinksTo( $options = array() ) {
2916                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2917         }
2918
2919         /**
2920          * Get an array of Title objects referring to non-existent articles linked from this page
2921          *
2922          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2923          * @return Array of Title the Title objects
2924          */
2925         public function getBrokenLinksFrom() {
2926                 if ( $this->getArticleId() == 0 ) {
2927                         # All links from article ID 0 are false positives
2928                         return array();
2929                 }
2930
2931                 $dbr = wfGetDB( DB_SLAVE );
2932                 $res = $dbr->select(
2933                         array( 'page', 'pagelinks' ),
2934                         array( 'pl_namespace', 'pl_title' ),
2935                         array(
2936                                 'pl_from' => $this->getArticleId(),
2937                                 'page_namespace IS NULL'
2938                         ),
2939                         __METHOD__, array(),
2940                         array(
2941                                 'page' => array(
2942                                         'LEFT JOIN',
2943                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2944                                 )
2945                         )
2946                 );
2947
2948                 $retVal = array();
2949                 foreach ( $res as $row ) {
2950                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2951                 }
2952                 return $retVal;
2953         }
2954
2955
2956         /**
2957          * Get a list of URLs to purge from the Squid cache when this
2958          * page changes
2959          *
2960          * @return Array of String the URLs
2961          */
2962         public function getSquidURLs() {
2963                 global $wgContLang;
2964
2965                 $urls = array(
2966                         $this->getInternalURL(),
2967                         $this->getInternalURL( 'action=history' )
2968                 );
2969
2970                 // purge variant urls as well
2971                 if ( $wgContLang->hasVariants() ) {
2972                         $variants = $wgContLang->getVariants();
2973                         foreach ( $variants as $vCode ) {
2974                                 $urls[] = $this->getInternalURL( '', $vCode );
2975                         }
2976                 }
2977
2978                 return $urls;
2979         }
2980
2981         /**
2982          * Purge all applicable Squid URLs
2983          */
2984         public function purgeSquid() {
2985                 global $wgUseSquid;
2986                 if ( $wgUseSquid ) {
2987                         $urls = $this->getSquidURLs();
2988                         $u = new SquidUpdate( $urls );
2989                         $u->doUpdate();
2990                 }
2991         }
2992
2993         /**
2994          * Move this page without authentication
2995          *
2996          * @param $nt Title the new page Title
2997          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2998          */
2999         public function moveNoAuth( &$nt ) {
3000                 return $this->moveTo( $nt, false );
3001         }
3002
3003         /**
3004          * Check whether a given move operation would be valid.
3005          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3006          *
3007          * @param $nt Title the new title
3008          * @param $auth Bool indicates whether $wgUser's permissions
3009          *  should be checked
3010          * @param $reason String is the log summary of the move, used for spam checking
3011          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3012          */
3013         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3014                 global $wgUser;
3015
3016                 $errors = array();
3017                 if ( !$nt ) {
3018                         // Normally we'd add this to $errors, but we'll get
3019                         // lots of syntax errors if $nt is not an object
3020                         return array( array( 'badtitletext' ) );
3021                 }
3022                 if ( $this->equals( $nt ) ) {
3023                         $errors[] = array( 'selfmove' );
3024                 }
3025                 if ( !$this->isMovable() ) {
3026                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3027                 }
3028                 if ( $nt->getInterwiki() != '' ) {
3029                         $errors[] = array( 'immobile-target-namespace-iw' );
3030                 }
3031                 if ( !$nt->isMovable() ) {
3032                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3033                 }
3034
3035                 $oldid = $this->getArticleID();
3036                 $newid = $nt->getArticleID();
3037
3038                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3039                         $errors[] = array( 'articleexists' );
3040                 }
3041                 if ( ( $this->getDBkey() == '' ) ||
3042                          ( !$oldid ) ||
3043                          ( $nt->getDBkey() == '' ) ) {
3044                         $errors[] = array( 'badarticleerror' );
3045                 }
3046
3047                 // Image-specific checks
3048                 if ( $this->getNamespace() == NS_FILE ) {
3049                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3050                 }
3051
3052                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3053                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3054                 }
3055
3056                 if ( $auth ) {
3057                         $errors = wfMergeErrorArrays( $errors,
3058                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3059                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3060                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3061                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3062                 }
3063
3064                 $match = EditPage::matchSummarySpamRegex( $reason );
3065                 if ( $match !== false ) {
3066                         // This is kind of lame, won't display nice
3067                         $errors[] = array( 'spamprotectiontext' );
3068                 }
3069
3070                 $err = null;
3071                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3072                         $errors[] = array( 'hookaborted', $err );
3073                 }
3074
3075                 # The move is allowed only if (1) the target doesn't exist, or
3076                 # (2) the target is a redirect to the source, and has no history
3077                 # (so we can undo bad moves right after they're done).
3078
3079                 if ( 0 != $newid ) { # Target exists; check for validity
3080                         if ( !$this->isValidMoveTarget( $nt ) ) {
3081                                 $errors[] = array( 'articleexists' );
3082                         }
3083                 } else {
3084                         $tp = $nt->getTitleProtection();
3085                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3086                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3087                                 $errors[] = array( 'cantmove-titleprotected' );
3088                         }
3089                 }
3090                 if ( empty( $errors ) ) {
3091                         return true;
3092                 }
3093                 return $errors;
3094         }
3095
3096         /**
3097          * Check if the requested move target is a valid file move target
3098          * @param Title $nt Target title
3099          * @return array List of errors
3100          */
3101         protected function validateFileMoveOperation( $nt ) {
3102                 global $wgUser;
3103
3104                 $errors = array();
3105
3106                 if ( $nt->getNamespace() != NS_FILE ) {
3107                         $errors[] = array( 'imagenocrossnamespace' );
3108                 }
3109
3110                 $file = wfLocalFile( $this );
3111                 if ( $file->exists() ) {
3112                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3113                                 $errors[] = array( 'imageinvalidfilename' );
3114                         }
3115                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3116                                 $errors[] = array( 'imagetypemismatch' );
3117                         }
3118                 }
3119
3120                 $destFile = wfLocalFile( $nt );
3121                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3122                         $errors[] = array( 'file-exists-sharedrepo' );
3123                 }
3124
3125                 return $errors;
3126         }
3127
3128         /**
3129          * Move a title to a new location
3130          *
3131          * @param $nt Title the new title
3132          * @param $auth Bool indicates whether $wgUser's permissions
3133          *  should be checked
3134          * @param $reason String the reason for the move
3135          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3136          *  Ignored if the user doesn't have the suppressredirect right.
3137          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3138          */
3139         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3140                 global $wgContLang, $wgEnableInterwikiTemplatesTracking, $wgGlobalDatabase;
3141
3142                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3143                 if ( is_array( $err ) ) {
3144                         return $err;
3145                 }
3146
3147                 // If it is a file, move it first. It is done before all other moving stuff is
3148                 // done because it's hard to revert
3149                 $dbw = wfGetDB( DB_MASTER );
3150                 if ( $this->getNamespace() == NS_FILE ) {
3151                         $file = wfLocalFile( $this );
3152                         if ( $file->exists() ) {
3153                                 $status = $file->move( $nt );
3154                                 if ( !$status->isOk() ) {
3155                                         return $status->getErrorsArray();
3156                                 }
3157                         }
3158                 }
3159
3160                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3161                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3162                 $protected = $this->isProtected();
3163                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3164
3165                 // Do the actual move
3166                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3167                 if ( is_array( $err ) ) {
3168                         # @todo FIXME: What about the File we have already moved?
3169                         $dbw->rollback();
3170                         return $err;
3171                 }
3172
3173                 $redirid = $this->getArticleID();
3174
3175                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3176                 // cl_timestamp, which may disturb time-based lists on some sites.
3177                 $prefixes = $dbw->select(
3178                         'categorylinks',
3179                         array( 'cl_sortkey_prefix', 'cl_to' ),
3180                         array( 'cl_from' => $pageid ),
3181                         __METHOD__
3182                 );
3183                 foreach ( $prefixes as $prefixRow ) {
3184                         $prefix = $prefixRow->cl_sortkey_prefix;
3185                         $catTo = $prefixRow->cl_to;
3186                         $dbw->update( 'categorylinks',
3187                                 array(
3188                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3189                                                 $nt->getCategorySortkey( $prefix ) ),
3190                                         'cl_timestamp=cl_timestamp' ),
3191                                 array(
3192                                         'cl_from' => $pageid,
3193                                         'cl_to' => $catTo ),
3194                                 __METHOD__
3195                         );
3196                 }
3197
3198                 if ( $wgEnableInterwikiTemplatesTracking && $wgGlobalDatabase ) {
3199                         $dbw2 = wfGetDB( DB_MASTER, array(), $wgGlobalDatabase );
3200                         $dbw2->update( 'globaltemplatelinks',
3201                                                 array(  'gtl_from_namespace' => $nt->getNamespace(),
3202                                                                 'gtl_from_title' => $nt->getText() ),
3203                                                 array ( 'gtl_from_page' => $pageid ),
3204                                                 __METHOD__ );
3205                 }
3206
3207                 if ( $protected ) {
3208                         # Protect the redirect title as the title used to be...
3209                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3210                                 array(
3211                                         'pr_page'    => $redirid,
3212                                         'pr_type'    => 'pr_type',
3213                                         'pr_level'   => 'pr_level',
3214                                         'pr_cascade' => 'pr_cascade',
3215                                         'pr_user'    => 'pr_user',
3216                                         'pr_expiry'  => 'pr_expiry'
3217                                 ),
3218                                 array( 'pr_page' => $pageid ),
3219                                 __METHOD__,
3220                                 array( 'IGNORE' )
3221                         );
3222                         # Update the protection log
3223                         $log = new LogPage( 'protect' );
3224                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3225                         if ( $reason ) {
3226                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3227                         }
3228                         // @todo FIXME: $params?
3229                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3230                 }
3231
3232                 # Update watchlists
3233                 $oldnamespace = $this->getNamespace() & ~1;
3234                 $newnamespace = $nt->getNamespace() & ~1;
3235                 $oldtitle = $this->getDBkey();
3236                 $newtitle = $nt->getDBkey();
3237
3238                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3239                         WatchedItem::duplicateEntries( $this, $nt );
3240                 }
3241
3242                 # Update search engine
3243                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3244                 $u->doUpdate();
3245                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3246                 $u->doUpdate();
3247
3248                 $dbw->commit();
3249
3250                 # Update site_stats
3251                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3252                         # No longer a content page
3253                         # Not viewed, edited, removing
3254                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3255                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3256                         # Now a content page
3257                         # Not viewed, edited, adding
3258                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3259                 } elseif ( $pageCountChange ) {
3260                         # Redirect added
3261                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3262                 } else {
3263                         # Nothing special
3264                         $u = false;
3265                 }
3266                 if ( $u ) {
3267                         $u->doUpdate();
3268                 }
3269
3270                 # Update message cache for interface messages
3271                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3272                         # @bug 17860: old article can be deleted, if this the case,
3273                         # delete it from message cache
3274                         if ( $this->getArticleID() === 0 ) {
3275                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3276                         } else {
3277                                 $oldarticle = new Article( $this );
3278                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3279                         }
3280                 }
3281                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3282                         $newarticle = new Article( $nt );
3283                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3284                 }
3285
3286                 global $wgUser;
3287                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3288                 return true;
3289         }
3290
3291         /**
3292          * Move page to a title which is either a redirect to the
3293          * source page or nonexistent
3294          *
3295          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3296          * @param $reason String The reason for the move
3297          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3298          *   if the user doesn't have the suppressredirect right
3299          */
3300         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3301                 global $wgUseSquid, $wgUser, $wgContLang, $wgEnableInterwikiTemplatesTracking, $wgGlobalDatabase;
3302
3303                 $moveOverRedirect = $nt->exists();
3304
3305                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3306                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3307
3308                 if ( $reason ) {
3309                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3310                 }
3311                 # Truncate for whole multibyte characters.
3312                 $comment = $wgContLang->truncate( $comment, 255 );
3313
3314                 $oldid = $this->getArticleID();
3315                 $latest = $this->getLatestRevID();
3316
3317                 $oldns = $this->getNamespace();
3318                 $olddbk = $this->getDBkey();
3319
3320                 $dbw = wfGetDB( DB_MASTER );
3321
3322                 if ( $moveOverRedirect ) {
3323                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3324
3325                         $newid = $nt->getArticleID();
3326                         $newns = $nt->getNamespace();
3327                         $newdbk = $nt->getDBkey();
3328
3329                         # Delete the old redirect. We don't save it to history since
3330                         # by definition if we've got here it's rather uninteresting.
3331                         # We have to remove it so that the next step doesn't trigger
3332                         # a conflict on the unique namespace+title index...
3333                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3334                         if ( !$dbw->cascadingDeletes() ) {
3335                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3336                                 global $wgUseTrackbacks;
3337                                 if ( $wgUseTrackbacks ) {
3338                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3339                                 }
3340                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3341                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3342                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3343                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3344                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3345                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3346                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3347                         }
3348                         // If the target page was recently created, it may have an entry in recentchanges still
3349                         $dbw->delete( 'recentchanges',
3350                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3351                                 __METHOD__
3352                         );
3353
3354                          if ( $wgEnableInterwikiTemplatesTracking && $wgGlobalDatabase ) {
3355                                 $dbw2 = wfGetDB( DB_MASTER, array(), $wgGlobalDatabase );
3356                                 $dbw2->delete( 'globaltemplatelinks',
3357                                                         array(  'gtl_from_wiki' => wfGetID(),
3358                                                                         'gtl_from_page' => $newid ),
3359                                                         __METHOD__ );
3360                         }
3361                 }
3362
3363                 # Save a null revision in the page's history notifying of the move
3364                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3365                 if ( !is_object( $nullRevision ) ) {
3366                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3367                 }
3368                 $nullRevId = $nullRevision->insertOn( $dbw );
3369
3370                 $now = wfTimestampNow();
3371                 # Change the name of the target page:
3372                 $dbw->update( 'page',
3373                         /* SET */ array(
3374                                 'page_touched'   => $dbw->timestamp( $now ),
3375                                 'page_namespace' => $nt->getNamespace(),
3376                                 'page_title'     => $nt->getDBkey(),
3377                                 'page_latest'    => $nullRevId,
3378                         ),
3379                         /* WHERE */ array( 'page_id' => $oldid ),
3380                         __METHOD__
3381                 );
3382                 $nt->resetArticleID( $oldid );
3383
3384                 $article = new Article( $nt );
3385                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3386                 $article->setCachedLastEditTime( $now );
3387
3388                 # Recreate the redirect, this time in the other direction.
3389                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3390                         $mwRedir = MagicWord::get( 'redirect' );
3391                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3392                         $redirectArticle = new Article( $this );
3393                         $newid = $redirectArticle->insertOn( $dbw );
3394                         $redirectRevision = new Revision( array(
3395                                 'page'    => $newid,
3396                                 'comment' => $comment,
3397                                 'text'    => $redirectText ) );
3398                         $redirectRevision->insertOn( $dbw );
3399                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3400
3401                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3402
3403                         # Now, we record the link from the redirect to the new title.
3404                         # It should have no other outgoing links...
3405                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3406                         $dbw->insert( 'pagelinks',
3407                                 array(
3408                                         'pl_from'      => $newid,
3409                                         'pl_namespace' => $nt->getNamespace(),
3410                                         'pl_title'     => $nt->getDBkey() ),
3411                                 __METHOD__ );
3412                         $redirectSuppressed = false;
3413                 } else {
3414                         // Get rid of old new page entries in Special:NewPages and RC.
3415                         // Needs to be before $this->resetArticleID( 0 ).
3416                         $dbw->delete( 'recentchanges', array(
3417                                         'rc_timestamp' => $dbw->timestamp( $this->getEarliestRevTime() ),
3418                                         'rc_namespace' => $oldns,
3419                                         'rc_title' => $olddbk,
3420                                         'rc_new' => 1
3421                                 ),
3422                                 __METHOD__
3423                         );
3424
3425                         $this->resetArticleID( 0 );
3426                         $redirectSuppressed = true;
3427                 }
3428
3429                 # Log the move
3430                 $log = new LogPage( 'move' );
3431                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3432                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3433
3434                 # Purge caches for old and new titles
3435                 if ( $moveOverRedirect ) {
3436                         # A simple purge is enough when moving over a redirect
3437                         $nt->purgeSquid();
3438                 } else {
3439                         # Purge caches as per article creation, including any pages that link to this title
3440                         Article::onArticleCreate( $nt );
3441                 }
3442                 $this->purgeSquid();
3443         }
3444
3445         /**
3446          * Move this page's subpages to be subpages of $nt
3447          *
3448          * @param $nt Title Move target
3449          * @param $auth bool Whether $wgUser's permissions should be checked
3450          * @param $reason string The reason for the move
3451          * @param $createRedirect bool Whether to create redirects from the old subpages to
3452          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3453          * @return mixed array with old page titles as keys, and strings (new page titles) or
3454          *     arrays (errors) as values, or an error array with numeric indices if no pages
3455          *     were moved
3456          */
3457         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3458                 global $wgMaximumMovedPages;
3459                 // Check permissions
3460                 if ( !$this->userCan( 'move-subpages' ) ) {
3461                         return array( 'cant-move-subpages' );
3462                 }
3463                 // Do the source and target namespaces support subpages?
3464                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3465                         return array( 'namespace-nosubpages',
3466                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3467                 }
3468                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3469                         return array( 'namespace-nosubpages',
3470                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3471                 }
3472
3473                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3474                 $retval = array();
3475                 $count = 0;
3476                 foreach ( $subpages as $oldSubpage ) {
3477                         $count++;
3478                         if ( $count > $wgMaximumMovedPages ) {
3479                                 $retval[$oldSubpage->getPrefixedTitle()] =
3480                                                 array( 'movepage-max-pages',
3481                                                         $wgMaximumMovedPages );
3482                                 break;
3483                         }
3484
3485                         // We don't know whether this function was called before
3486                         // or after moving the root page, so check both
3487                         // $this and $nt
3488                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3489                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3490                         {
3491                                 // When moving a page to a subpage of itself,
3492                                 // don't move it twice
3493                                 continue;
3494                         }
3495                         $newPageName = preg_replace(
3496                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3497                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3498                                         $oldSubpage->getDBkey() );
3499                         if ( $oldSubpage->isTalkPage() ) {
3500                                 $newNs = $nt->getTalkPage()->getNamespace();
3501                         } else {
3502                                 $newNs = $nt->getSubjectPage()->getNamespace();
3503                         }
3504                         # Bug 14385: we need makeTitleSafe because the new page names may
3505                         # be longer than 255 characters.
3506                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3507
3508                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3509                         if ( $success === true ) {
3510                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3511                         } else {
3512                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3513                         }
3514                 }
3515                 return $retval;
3516         }
3517
3518         /**
3519          * Checks if this page is just a one-rev redirect.
3520          * Adds lock, so don't use just for light purposes.
3521          *
3522          * @return Bool
3523          */
3524         public function isSingleRevRedirect() {
3525                 $dbw = wfGetDB( DB_MASTER );
3526                 # Is it a redirect?
3527                 $row = $dbw->selectRow( 'page',
3528                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3529                         $this->pageCond(),
3530                         __METHOD__,
3531                         array( 'FOR UPDATE' )
3532                 );
3533                 # Cache some fields we may want
3534                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3535                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3536                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3537                 if ( !$this->mRedirect ) {
3538                         return false;
3539                 }
3540                 # Does the article have a history?
3541                 $row = $dbw->selectField( array( 'page', 'revision' ),
3542                         'rev_id',
3543                         array( 'page_namespace' => $this->getNamespace(),
3544                                 'page_title' => $this->getDBkey(),
3545                                 'page_id=rev_page',
3546                                 'page_latest != rev_id'
3547                         ),
3548                         __METHOD__,
3549                         array( 'FOR UPDATE' )
3550                 );
3551                 # Return true if there was no history
3552                 return ( $row === false );
3553         }
3554
3555         /**
3556          * Checks if $this can be moved to a given Title
3557          * - Selects for update, so don't call it unless you mean business
3558          *
3559          * @param $nt Title the new title to check
3560          * @return Bool
3561          */
3562         public function isValidMoveTarget( $nt ) {
3563                 # Is it an existing file?
3564                 if ( $nt->getNamespace() == NS_FILE ) {
3565                         $file = wfLocalFile( $nt );
3566                         if ( $file->exists() ) {
3567                                 wfDebug( __METHOD__ . ": file exists\n" );
3568                                 return false;
3569                         }
3570                 }
3571                 # Is it a redirect with no history?
3572                 if ( !$nt->isSingleRevRedirect() ) {
3573                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3574                         return false;
3575                 }
3576                 # Get the article text
3577                 $rev = Revision::newFromTitle( $nt );
3578                 $text = $rev->getText();
3579                 # Does the redirect point to the source?
3580                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3581                 $m = array();
3582                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3583                         $redirTitle = Title::newFromText( $m[1] );
3584                         if ( !is_object( $redirTitle ) ||
3585                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3586                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3587                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3588                                 return false;
3589                         }
3590                 } else {
3591                         # Fail safe
3592                         wfDebug( __METHOD__ . ": failsafe\n" );
3593                         return false;
3594                 }
3595                 return true;
3596         }
3597
3598         /**
3599          * Can this title be added to a user's watchlist?
3600          *
3601          * @return Bool TRUE or FALSE
3602          */
3603         public function isWatchable() {
3604                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3605         }
3606
3607         /**
3608          * Get categories to which this Title belongs and return an array of
3609          * categories' names.
3610          *
3611          * @return Array of parents in the form:
3612          *        $parent => $currentarticle
3613          */
3614         public function getParentCategories() {
3615                 global $wgContLang;
3616
3617                 $data = array();
3618
3619                 $titleKey = $this->getArticleId();
3620
3621                 if ( $titleKey === 0 ) {
3622                         return $data;
3623                 }
3624
3625                 $dbr = wfGetDB( DB_SLAVE );
3626
3627                 $res = $dbr->select( 'categorylinks', '*',
3628                         array(
3629                                 'cl_from' => $titleKey,
3630                         ),
3631                         __METHOD__,
3632                         array()
3633                 );
3634
3635                 if ( $dbr->numRows( $res ) > 0 ) {
3636                         foreach ( $res as $row ) {
3637                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3638                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3639                         }
3640                 }
3641                 return $data;
3642         }
3643
3644         /**
3645          * Get a tree of parent categories
3646          *
3647          * @param $children Array with the children in the keys, to check for circular refs
3648          * @return Array Tree of parent categories
3649          */
3650         public function getParentCategoryTree( $children = array() ) {
3651                 $stack = array();
3652                 $parents = $this->getParentCategories();
3653
3654                 if ( $parents ) {
3655                         foreach ( $parents as $parent => $current ) {
3656                                 if ( array_key_exists( $parent, $children ) ) {
3657                                         # Circular reference
3658                                         $stack[$parent] = array();
3659                                 } else {
3660                                         $nt = Title::newFromText( $parent );
3661                                         if ( $nt ) {
3662                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3663                                         }
3664                                 }
3665                         }
3666                 }
3667
3668                 return $stack;
3669         }
3670
3671         /**
3672          * Get an associative array for selecting this title from
3673          * the "page" table
3674          *
3675          * @return Array suitable for the $where parameter of DB::select()
3676          */
3677         public function pageCond() {
3678                 if ( $this->mArticleID > 0 ) {
3679                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3680                         return array( 'page_id' => $this->mArticleID );
3681                 } else {
3682                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3683                 }
3684         }
3685
3686         /**
3687          * Get the revision ID of the previous revision
3688          *
3689          * @param $revId Int Revision ID. Get the revision that was before this one.
3690          * @param $flags Int Title::GAID_FOR_UPDATE
3691          * @return Int|Bool Old revision ID, or FALSE if none exists
3692          */
3693         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3694                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3695                 return $db->selectField( 'revision', 'rev_id',
3696                         array(
3697                                 'rev_page' => $this->getArticleId( $flags ),
3698                                 'rev_id < ' . intval( $revId )
3699                         ),
3700                         __METHOD__,
3701                         array( 'ORDER BY' => 'rev_id DESC' )
3702                 );
3703         }
3704
3705         /**
3706          * Get the revision ID of the next revision
3707          *
3708          * @param $revId Int Revision ID. Get the revision that was after this one.
3709          * @param $flags Int Title::GAID_FOR_UPDATE
3710          * @return Int|Bool Next revision ID, or FALSE if none exists
3711          */
3712         public function getNextRevisionID( $revId, $flags = 0 ) {
3713                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3714                 return $db->selectField( 'revision', 'rev_id',
3715                         array(
3716                                 'rev_page' => $this->getArticleId( $flags ),
3717                                 'rev_id > ' . intval( $revId )
3718                         ),
3719                         __METHOD__,
3720                         array( 'ORDER BY' => 'rev_id' )
3721                 );
3722         }
3723
3724         /**
3725          * Get the first revision of the page
3726          *
3727          * @param $flags Int Title::GAID_FOR_UPDATE
3728          * @return Revision|Null if page doesn't exist
3729          */
3730         public function getFirstRevision( $flags = 0 ) {
3731                 $pageId = $this->getArticleId( $flags );
3732                 if ( $pageId ) {
3733                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3734                         $row = $db->selectRow( 'revision', '*',
3735                                 array( 'rev_page' => $pageId ),
3736                                 __METHOD__,
3737                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3738                         );
3739                         if ( $row ) {
3740                                 return new Revision( $row );
3741                         }
3742                 }
3743                 return null;
3744         }
3745
3746         /**
3747          * Get the oldest revision timestamp of this page
3748          *
3749          * @param $flags Int Title::GAID_FOR_UPDATE
3750          * @return String: MW timestamp
3751          */
3752         public function getEarliestRevTime( $flags = 0 ) {
3753                 $rev = $this->getFirstRevision( $flags );
3754                 return $rev ? $rev->getTimestamp() : null;
3755         }
3756
3757         /**
3758          * Check if this is a new page
3759          *
3760          * @return bool
3761          */
3762         public function isNewPage() {
3763                 $dbr = wfGetDB( DB_SLAVE );
3764                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3765         }
3766
3767         /**
3768          * Get the number of revisions between the given revision.
3769          * Used for diffs and other things that really need it.
3770          *
3771          * @param $old int|Revision Old revision or rev ID (first before range)
3772          * @param $new int|Revision New revision or rev ID (first after range)
3773          * @return Int Number of revisions between these revisions.
3774          */
3775         public function countRevisionsBetween( $old, $new ) {
3776                 if ( !( $old instanceof Revision ) ) {
3777                         $old = Revision::newFromTitle( $this, (int)$old );
3778                 }
3779                 if ( !( $new instanceof Revision ) ) {
3780                         $new = Revision::newFromTitle( $this, (int)$new );
3781                 }
3782                 if ( !$old || !$new ) {
3783                         return 0; // nothing to compare
3784                 }
3785                 $dbr = wfGetDB( DB_SLAVE );
3786                 return (int)$dbr->selectField( 'revision', 'count(*)',
3787                         array(
3788                                 'rev_page' => $this->getArticleId(),
3789                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3790                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3791                         ),
3792                         __METHOD__
3793                 );
3794         }
3795
3796         /**
3797          * Get the number of authors between the given revision IDs.
3798          * Used for diffs and other things that really need it.
3799          *
3800          * @param $old int|Revision Old revision or rev ID (first before range)
3801          * @param $new int|Revision New revision or rev ID (first after range)
3802          * @param $limit Int Maximum number of authors
3803          * @return Int Number of revision authors between these revisions.
3804          */
3805         public function countAuthorsBetween( $old, $new, $limit ) {
3806                 if ( !( $old instanceof Revision ) ) {
3807                         $old = Revision::newFromTitle( $this, (int)$old );
3808                 }
3809                 if ( !( $new instanceof Revision ) ) {
3810                         $new = Revision::newFromTitle( $this, (int)$new );
3811                 }
3812                 if ( !$old || !$new ) {
3813                         return 0; // nothing to compare
3814                 }
3815                 $dbr = wfGetDB( DB_SLAVE );
3816                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3817                         array(
3818                                 'rev_page' => $this->getArticleID(),
3819                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3820                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3821                         ), __METHOD__,
3822                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3823                 );
3824                 return (int)$dbr->numRows( $res );
3825         }
3826
3827         /**
3828          * Compare with another title.
3829          *
3830          * @param $title Title
3831          * @return Bool
3832          */
3833         public function equals( Title $title ) {
3834                 // Note: === is necessary for proper matching of number-like titles.
3835                 return $this->getInterwiki() === $title->getInterwiki()
3836                         && $this->getNamespace() == $title->getNamespace()
3837                         && $this->getDBkey() === $title->getDBkey();
3838         }
3839
3840         /**
3841          * Callback for usort() to do title sorts by (namespace, title)
3842          *
3843          * @param $a Title
3844          * @param $b Title
3845          *
3846          * @return Integer: result of string comparison, or namespace comparison
3847          */
3848         public static function compare( $a, $b ) {
3849                 if ( $a->getNamespace() == $b->getNamespace() ) {
3850                         return strcmp( $a->getText(), $b->getText() );
3851                 } else {
3852                         return $a->getNamespace() - $b->getNamespace();
3853                 }
3854         }
3855
3856         /**
3857          * Return a string representation of this title
3858          *
3859          * @return String representation of this title
3860          */
3861         public function __toString() {
3862                 return $this->getPrefixedText();
3863         }
3864
3865         /**
3866          * Check if page exists.  For historical reasons, this function simply
3867          * checks for the existence of the title in the page table, and will
3868          * thus return false for interwiki links, special pages and the like.
3869          * If you want to know if a title can be meaningfully viewed, you should
3870          * probably call the isKnown() method instead.
3871          *
3872          * @return Bool
3873          */
3874         public function exists() {
3875                 return $this->getArticleId() != 0;
3876         }
3877
3878         /**
3879          * Should links to this title be shown as potentially viewable (i.e. as
3880          * "bluelinks"), even if there's no record by this title in the page
3881          * table?
3882          *
3883          * This function is semi-deprecated for public use, as well as somewhat
3884          * misleadingly named.  You probably just want to call isKnown(), which
3885          * calls this function internally.
3886          *
3887          * (ISSUE: Most of these checks are cheap, but the file existence check
3888          * can potentially be quite expensive.  Including it here fixes a lot of
3889          * existing code, but we might want to add an optional parameter to skip
3890          * it and any other expensive checks.)
3891          *
3892          * @return Bool
3893          */
3894         public function isAlwaysKnown() {
3895                 if ( $this->mInterwiki != '' ) {
3896                         return true;  // any interwiki link might be viewable, for all we know
3897                 }
3898                 switch( $this->mNamespace ) {
3899                         case NS_MEDIA:
3900                         case NS_FILE:
3901                                 // file exists, possibly in a foreign repo
3902                                 return (bool)wfFindFile( $this );
3903                         case NS_SPECIAL:
3904                                 // valid special page
3905                                 return SpecialPageFactory::exists( $this->getDBkey() );
3906                         case NS_MAIN:
3907                                 // selflink, possibly with fragment
3908                                 return $this->mDbkeyform == '';
3909                         case NS_MEDIAWIKI:
3910                                 // known system message
3911                                 return $this->getDefaultMessageText() !== false;
3912                         default:
3913                                 return false;
3914                 }
3915         }
3916
3917         /**
3918          * Does this title refer to a page that can (or might) be meaningfully
3919          * viewed?  In particular, this function may be used to determine if
3920          * links to the title should be rendered as "bluelinks" (as opposed to
3921          * "redlinks" to non-existent pages).
3922          *
3923          * @return Bool
3924          */
3925         public function isKnown() {
3926                 return $this->isAlwaysKnown() || $this->exists();
3927         }
3928
3929         /**
3930          * Does this page have source text?
3931          *
3932          * @return Boolean
3933          */
3934         public function hasSourceText() {
3935                 if ( $this->exists() ) {
3936                         return true;
3937                 }
3938
3939                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3940                         // If the page doesn't exist but is a known system message, default
3941                         // message content will be displayed, same for language subpages
3942                         return $this->getDefaultMessageText() !== false;
3943                 }
3944
3945                 return false;
3946         }
3947
3948         /**
3949          * Get the default message text or false if the message doesn't exist
3950          *
3951          * @return String or false
3952          */
3953         public function getDefaultMessageText() {
3954                 global $wgContLang;
3955
3956                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3957                         return false;
3958                 }
3959
3960                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3961                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3962
3963                 if ( $message->exists() ) {
3964                         return $message->plain();
3965                 } else {
3966                         return false;
3967                 }
3968         }
3969
3970         /**
3971          * Is this in a namespace that allows actual pages?
3972          *
3973          * @return Bool
3974          * @internal note -- uses hardcoded namespace index instead of constants
3975          */
3976         public function canExist() {
3977                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3978         }
3979
3980         /**
3981          * Update page_touched timestamps and send squid purge messages for
3982          * pages linking to this title. May be sent to the job queue depending
3983          * on the number of links. Typically called on create and delete.
3984          */
3985         public function touchLinks() {
3986                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3987                 $u->doUpdate();
3988
3989                 if ( $this->getNamespace() == NS_CATEGORY ) {
3990                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3991                         $u->doUpdate();
3992                 }
3993         }
3994
3995         /**
3996          * Get the last touched timestamp
3997          *
3998          * @param $db DatabaseBase: optional db
3999          * @return String last-touched timestamp
4000          */
4001         public function getTouched( $db = null ) {
4002                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4003                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4004                 return $touched;
4005         }
4006
4007         /**
4008          * Get the timestamp when this page was updated since the user last saw it.
4009          *
4010          * @param $user User
4011          * @return String|Null
4012          */
4013         public function getNotificationTimestamp( $user = null ) {
4014                 global $wgUser, $wgShowUpdatedMarker;
4015                 // Assume current user if none given
4016                 if ( !$user ) {
4017                         $user = $wgUser;
4018                 }
4019                 // Check cache first
4020                 $uid = $user->getId();
4021                 // avoid isset here, as it'll return false for null entries
4022                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4023                         return $this->mNotificationTimestamp[$uid];
4024                 }
4025                 if ( !$uid || !$wgShowUpdatedMarker ) {
4026                         return $this->mNotificationTimestamp[$uid] = false;
4027                 }
4028                 // Don't cache too much!
4029                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4030                         $this->mNotificationTimestamp = array();
4031                 }
4032                 $dbr = wfGetDB( DB_SLAVE );
4033                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4034                         'wl_notificationtimestamp',
4035                         array( 'wl_namespace' => $this->getNamespace(),
4036                                 'wl_title' => $this->getDBkey(),
4037                                 'wl_user' => $user->getId()
4038                         ),
4039                         __METHOD__
4040                 );
4041                 return $this->mNotificationTimestamp[$uid];
4042         }
4043
4044         /**
4045          * Get the trackback URL for this page
4046          *
4047          * @return String Trackback URL
4048          */
4049         public function trackbackURL() {
4050                 global $wgScriptPath, $wgServer, $wgScriptExtension;
4051
4052                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
4053                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
4054         }
4055
4056         /**
4057          * Get the trackback RDF for this page
4058          *
4059          * @return String Trackback RDF
4060          */
4061         public function trackbackRDF() {
4062                 $url = htmlspecialchars( $this->getFullURL() );
4063                 $title = htmlspecialchars( $this->getText() );
4064                 $tburl = $this->trackbackURL();
4065
4066                 // Autodiscovery RDF is placed in comments so HTML validator
4067                 // won't barf. This is a rather icky workaround, but seems
4068                 // frequently used by this kind of RDF thingy.
4069                 //
4070                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4071                 return "<!--
4072 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4073                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4074                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4075 <rdf:Description
4076    rdf:about=\"$url\"
4077    dc:identifier=\"$url\"
4078    dc:title=\"$title\"
4079    trackback:ping=\"$tburl\" />
4080 </rdf:RDF>
4081 -->";
4082         }
4083
4084         /**
4085          * Generate strings used for xml 'id' names in monobook tabs
4086          *
4087          * @param $prepend string defaults to 'nstab-'
4088          * @return String XML 'id' name
4089          */
4090         public function getNamespaceKey( $prepend = 'nstab-' ) {
4091                 global $wgContLang;
4092                 // Gets the subject namespace if this title
4093                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4094                 // Checks if cononical namespace name exists for namespace
4095                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4096                         // Uses canonical namespace name
4097                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4098                 } else {
4099                         // Uses text of namespace
4100                         $namespaceKey = $this->getSubjectNsText();
4101                 }
4102                 // Makes namespace key lowercase
4103                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4104                 // Uses main
4105                 if ( $namespaceKey == '' ) {
4106                         $namespaceKey = 'main';
4107                 }
4108                 // Changes file to image for backwards compatibility
4109                 if ( $namespaceKey == 'file' ) {
4110                         $namespaceKey = 'image';
4111                 }
4112                 return $prepend . $namespaceKey;
4113         }
4114
4115         /**
4116          * Returns true if this is a special page.
4117          *
4118          * @return boolean
4119          */
4120         public function isSpecialPage() {
4121                 return $this->getNamespace() == NS_SPECIAL;
4122         }
4123
4124         /**
4125          * Returns true if this title resolves to the named special page
4126          *
4127          * @param $name String The special page name
4128          * @return boolean
4129          */
4130         public function isSpecial( $name ) {
4131                 if ( $this->getNamespace() == NS_SPECIAL ) {
4132                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4133                         if ( $name == $thisName ) {
4134                                 return true;
4135                         }
4136                 }
4137                 return false;
4138         }
4139
4140         /**
4141          * If the Title refers to a special page alias which is not the local default, resolve
4142          * the alias, and localise the name as necessary.  Otherwise, return $this
4143          *
4144          * @return Title
4145          */
4146         public function fixSpecialName() {
4147                 if ( $this->getNamespace() == NS_SPECIAL ) {
4148                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4149                         if ( $canonicalName ) {
4150                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4151                                 if ( $localName != $this->mDbkeyform ) {
4152                                         return Title::makeTitle( NS_SPECIAL, $localName );
4153                                 }
4154                         }
4155                 }
4156                 return $this;
4157         }
4158
4159         /**
4160          * Is this Title in a namespace which contains content?
4161          * In other words, is this a content page, for the purposes of calculating
4162          * statistics, etc?
4163          *
4164          * @return Boolean
4165          */
4166         public function isContentPage() {
4167                 return MWNamespace::isContent( $this->getNamespace() );
4168         }
4169
4170         /**
4171          * Get all extant redirects to this Title
4172          *
4173          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4174          * @return Array of Title redirects to this title
4175          */
4176         public function getRedirectsHere( $ns = null ) {
4177                 $redirs = array();
4178
4179                 $dbr = wfGetDB( DB_SLAVE );
4180                 $where = array(
4181                         'rd_namespace' => $this->getNamespace(),
4182                         'rd_title' => $this->getDBkey(),
4183                         'rd_from = page_id'
4184                 );
4185                 if ( !is_null( $ns ) ) {
4186                         $where['page_namespace'] = $ns;
4187                 }
4188
4189                 $res = $dbr->select(
4190                         array( 'redirect', 'page' ),
4191                         array( 'page_namespace', 'page_title' ),
4192                         $where,
4193                         __METHOD__
4194                 );
4195
4196                 foreach ( $res as $row ) {
4197                         $redirs[] = self::newFromRow( $row );
4198                 }
4199                 return $redirs;
4200         }
4201
4202         /**
4203          * Check if this Title is a valid redirect target
4204          *
4205          * @return Bool
4206          */
4207         public function isValidRedirectTarget() {
4208                 global $wgInvalidRedirectTargets;
4209
4210                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4211                 if ( $this->isSpecial( 'Userlogout' ) ) {
4212                         return false;
4213                 }
4214
4215                 foreach ( $wgInvalidRedirectTargets as $target ) {
4216                         if ( $this->isSpecial( $target ) ) {
4217                                 return false;
4218                         }
4219                 }
4220
4221                 return true;
4222         }
4223
4224         /**
4225          * Get a backlink cache object
4226          *
4227          * @return object BacklinkCache
4228          */
4229         function getBacklinkCache() {
4230                 if ( is_null( $this->mBacklinkCache ) ) {
4231                         $this->mBacklinkCache = new BacklinkCache( $this );
4232                 }
4233                 return $this->mBacklinkCache;
4234         }
4235
4236         /**
4237          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4238          *
4239          * @return Boolean
4240          */
4241         public function canUseNoindex() {
4242                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4243
4244                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4245                         ? $wgContentNamespaces
4246                         : $wgExemptFromUserRobotsControl;
4247
4248                 return !in_array( $this->mNamespace, $bannedNamespaces );
4249
4250         }
4251
4252         /**
4253          * Returns restriction types for the current Title
4254          *
4255          * @return array applicable restriction types
4256          */
4257         public function getRestrictionTypes() {
4258                 if ( $this->getNamespace() == NS_SPECIAL ) {
4259                         return array();
4260                 }
4261
4262                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4263
4264                 if ( $this->getNamespace() != NS_FILE ) {
4265                         # Remove the upload restriction for non-file titles
4266                         $types = array_diff( $types, array( 'upload' ) );
4267                 }
4268
4269                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4270
4271                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4272                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4273
4274                 return $types;
4275         }
4276         /**
4277          * Get a filtered list of all restriction types supported by this wiki.
4278          * @param bool $exists True to get all restriction types that apply to
4279          * titles that do exist, False for all restriction types that apply to
4280          * titles that do not exist
4281          * @return array
4282          */
4283         public static function getFilteredRestrictionTypes( $exists = true ) {
4284                 global $wgRestrictionTypes;
4285                 $types = $wgRestrictionTypes;
4286                 if ( $exists ) {
4287                         # Remove the create restriction for existing titles
4288                         $types = array_diff( $types, array( 'create' ) );
4289                 } else {
4290                         # Only the create and upload restrictions apply to non-existing titles
4291                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4292                 }
4293                 return $types;
4294         }
4295
4296         /**
4297          * Returns the raw sort key to be used for categories, with the specified
4298          * prefix.  This will be fed to Collation::getSortKey() to get a
4299          * binary sortkey that can be used for actual sorting.
4300          *
4301          * @param $prefix string The prefix to be used, specified using
4302          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4303          *   prefix.
4304          * @return string
4305          */
4306         public function getCategorySortkey( $prefix = '' ) {
4307                 $unprefixed = $this->getText();
4308
4309                 // Anything that uses this hook should only depend
4310                 // on the Title object passed in, and should probably
4311                 // tell the users to run updateCollations.php --force
4312                 // in order to re-sort existing category relations.
4313                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4314                 if ( $prefix !== '' ) {
4315                         # Separate with a line feed, so the unprefixed part is only used as
4316                         # a tiebreaker when two pages have the exact same prefix.
4317                         # In UCA, tab is the only character that can sort above LF
4318                         # so we strip both of them from the original prefix.
4319                         $prefix = strtr( $prefix, "\n\t", '  ' );
4320                         return "$prefix\n$unprefixed";
4321                 }
4322                 return $unprefixed;
4323         }
4324
4325         /**
4326          * Get the language in which the content of this page is written.
4327          * Defaults to $wgContLang, but in certain cases it can be e.g.
4328          * $wgLang (such as special pages, which are in the user language).
4329          *
4330          * @return object Language
4331          */
4332         public function getPageLanguage() {
4333                 global $wgLang;
4334                 if ( $this->getNamespace() == NS_SPECIAL ) {
4335                         // special pages are in the user language
4336                         return $wgLang;
4337                 } elseif ( $this->isRedirect() ) {
4338                         // the arrow on a redirect page is aligned according to the user language
4339                         return $wgLang;
4340                 } elseif ( $this->isCssOrJsPage() ) {
4341                         // css/js should always be LTR and is, in fact, English
4342                         return wfGetLangObj( 'en' );
4343                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4344                         // Parse mediawiki messages with correct target language
4345                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4346                         return wfGetLangObj( $lang );
4347                 }
4348                 global $wgContLang;
4349                 // If nothing special, it should be in the wiki content language
4350                 $pageLang = $wgContLang;
4351                 // Hook at the end because we don't want to override the above stuff
4352                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4353                 return wfGetLangObj( $pageLang );
4354         }
4355 }
4356
4357 /**
4358  * A BadTitle is generated in MediaWiki::parseTitle() if the title is invalid; the
4359  * software uses this to display an error page.  Internally it's basically a Title
4360  * for an empty special page
4361  */
4362 class BadTitle extends Title {
4363         public function __construct(){
4364                 $this->mTextform = '';
4365                 $this->mUrlform = '';
4366                 $this->mDbkeyform = '';
4367                 $this->mNamespace = NS_SPECIAL; // Stops talk page link, etc, being shown
4368         }
4369
4370         public function exists(){
4371                 return false;
4372         }
4373
4374         public function getPrefixedText(){
4375                 return '';
4376         }
4377
4378         public function getText(){
4379                 return '';
4380         }
4381
4382         public function getPrefixedURL(){
4383                 return '';
4384         }
4385
4386         public function getPrefixedDBKey(){
4387                 return '';
4388         }
4389 }