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          * Get the prefixed title with spaces, plus any fragment
 762          * (part beginning with '#')
 763          *
 764          * @return String the prefixed title, with spaces and the fragment, including '#'
 765          */
 766         public function getFullText() {
 767                 $text = $this->getPrefixedText();
 768                 if ( $this->mFragment != '' ) {
 769                         $text .= '#' . $this->mFragment;
 770                 }
 771                 return $text;
 772         }
 773
 774         /**
 775          * Get the base page name, i.e. the leftmost part before any slashes
 776          *
 777          * @return String Base name
 778          */
 779         public function getBaseText() {
 780                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 781                         return $this->getText();
 782                 }
 783
 784                 $parts = explode( '/', $this->getText() );
 785                 # Don't discard the real title if there's no subpage involved
 786                 if ( count( $parts ) > 1 ) {
 787                         unset( $parts[count( $parts ) - 1] );
 788                 }
 789                 return implode( '/', $parts );
 790         }
 791
 792         /**
 793          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
 794          *
 795          * @return String Subpage name
 796          */
 797         public function getSubpageText() {
 798                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 799                         return( $this->mTextform );
 800                 }
 801                 $parts = explode( '/', $this->mTextform );
 802                 return( $parts[count( $parts ) - 1] );
 803         }
 804
 805         /**
 806          * Get a URL-encoded form of the subpage text
 807          *
 808          * @return String URL-encoded subpage name
 809          */
 810         public function getSubpageUrlForm() {
 811                 $text = $this->getSubpageText();
 812                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 813                 return( $text );
 814         }
 815
 816         /**
 817          * Get a URL-encoded title (not an actual URL) including interwiki
 818          *
 819          * @return String the URL-encoded form
 820          */
 821         public function getPrefixedURL() {
 822                 $s = $this->prefix( $this->mDbkeyform );
 823                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 824                 return $s;
 825         }
 826
 827         /**
 828          * Get a real URL referring to this title, with interwiki link and
 829          * fragment
 830          *
 831          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 832          *   links. Can be specified as an associative array as well, e.g.,
 833          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 834          * @param $variant String language variant of url (for sr, zh..)
 835          * @return String the URL
 836          */
 837         public function getFullURL( $query = '', $variant = false ) {
 838                 global $wgServer, $wgRequest;
 839
 840                 if ( is_array( $query ) ) {
 841                         $query = wfArrayToCGI( $query );
 842                 }
 843
 844                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 845                 if ( !$interwiki ) {
 846                         $url = $this->getLocalURL( $query, $variant );
 847
 848                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 849                         // Correct fix would be to move the prepending elsewhere.
 850                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 851                                 $url = $wgServer . $url;
 852                         }
 853                 } else {
 854                         $namespace = $this->getNsText();
 855                         if ( $namespace != '' ) {
 856                                 # Can this actually happen? Interwikis shouldn't be parsed.
 857                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 858                                 $namespace .= ':';
 859                         }
 860                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 861                         $url = wfAppendQuery( $url, $query );
 862                 }
 863
 864                 # Finally, add the fragment.
 865                 $url .= $this->getFragmentForURL();
 866
 867                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 868                 return $url;
 869         }
 870
 871         /**
 872          * Get a URL with no fragment or server name.  If this page is generated
 873          * with action=render, $wgServer is prepended.
 874          *
 875          * @param $query Mixed: an optional query string; if not specified,
 876          *   $wgArticlePath will be used.  Can be specified as an associative array
 877          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 878          *   URL-escaped).
 879          * @param $variant String language variant of url (for sr, zh..)
 880          * @return String the URL
 881          */
 882         public function getLocalURL( $query = '', $variant = false ) {
 883                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 884                 global $wgVariantArticlePath, $wgContLang;
 885
 886                 if ( is_array( $query ) ) {
 887                         $query = wfArrayToCGI( $query );
 888                 }
 889
 890                 if ( $this->isExternal() ) {
 891                         $url = $this->getFullURL();
 892                         if ( $query ) {
 893                                 // This is currently only used for edit section links in the
 894                                 // context of interwiki transclusion. In theory we should
 895                                 // append the query to the end of any existing query string,
 896                                 // but interwiki transclusion is already broken in that case.
 897                                 $url .= "?$query";
 898                         }
 899                 } else {
 900                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 901                         if ( $query == '' ) {
 902                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 903                                         if ( !$wgVariantArticlePath ) {
 904                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 905                                         } else {
 906                                                 $variantArticlePath = $wgVariantArticlePath;
 907                                         }
 908                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 909                                         $url = str_replace( '$1', $dbkey, $url  );
 910                                 } else {
 911                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 912                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
 913                                 }
 914                         } else {
 915                                 global $wgActionPaths;
 916                                 $url = false;
 917                                 $matches = array();
 918                                 if ( !empty( $wgActionPaths ) &&
 919                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 920                                 {
 921                                         $action = urldecode( $matches[2] );
 922                                         if ( isset( $wgActionPaths[$action] ) ) {
 923                                                 $query = $matches[1];
 924                                                 if ( isset( $matches[4] ) ) {
 925                                                         $query .= $matches[4];
 926                                                 }
 927                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 928                                                 if ( $query != '' ) {
 929                                                         $url = wfAppendQuery( $url, $query );
 930                                                 }
 931                                         }
 932                                 }
 933
 934                                 if ( $url === false ) {
 935                                         if ( $query == '-' ) {
 936                                                 $query = '';
 937                                         }
 938                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 939                                 }
 940                         }
 941
 942                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
 943
 944                         // @todo FIXME: This causes breakage in various places when we
 945                         // actually expected a local URL and end up with dupe prefixes.
 946                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 947                                 $url = $wgServer . $url;
 948                         }
 949                 }
 950                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
 951                 return $url;
 952         }
 953
 954         /**
 955          * Get a URL that's the simplest URL that will be valid to link, locally,
 956          * to the current Title.  It includes the fragment, but does not include
 957          * the server unless action=render is used (or the link is external).  If
 958          * there's a fragment but the prefixed text is empty, we just return a link
 959          * to the fragment.
 960          *
 961          * The result obviously should not be URL-escaped, but does need to be
 962          * HTML-escaped if it's being output in HTML.
 963          *
 964          * @param $query Array of Strings An associative array of key => value pairs for the
 965          *   query string.  Keys and values will be escaped.
 966          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 967          *   for external links.  Default is "false" (same variant as current page,
 968          *   for anonymous users).
 969          * @return String the URL
 970          */
 971         public function getLinkUrl( $query = array(), $variant = false ) {
 972                 wfProfileIn( __METHOD__ );
 973                 if ( $this->isExternal() ) {
 974                         $ret = $this->getFullURL( $query );
 975                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 976                         $ret = $this->getFragmentForURL();
 977                 } else {
 978                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 979                 }
 980                 wfProfileOut( __METHOD__ );
 981                 return $ret;
 982         }
 983
 984         /**
 985          * Get an HTML-escaped version of the URL form, suitable for
 986          * using in a link, without a server name or fragment
 987          *
 988          * @param $query String an optional query string
 989          * @return String the URL
 990          */
 991         public function escapeLocalURL( $query = '' ) {
 992                 return htmlspecialchars( $this->getLocalURL( $query ) );
 993         }
 994
 995         /**
 996          * Get an HTML-escaped version of the URL form, suitable for
 997          * using in a link, including the server name and fragment
 998          *
 999          * @param $query String an optional query string
1000          * @return String the URL
1001          */
1002         public function escapeFullURL( $query = '' ) {
1003                 return htmlspecialchars( $this->getFullURL( $query ) );
1004         }
1005
1006         /**
1007          * Get the URL form for an internal link.
1008          * - Used in various Squid-related code, in case we have a different
1009          * internal hostname for the server from the exposed one.
1010          *
1011          * @param $query String an optional query string
1012          * @param $variant String language variant of url (for sr, zh..)
1013          * @return String the URL
1014          */
1015         public function getInternalURL( $query = '', $variant = false ) {
1016                 global $wgInternalServer, $wgServer;
1017                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1018                 $url = $server . $this->getLocalURL( $query, $variant );
1019                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1020                 return $url;
1021         }
1022
1023         /**
1024          * Get the edit URL for this Title
1025          *
1026          * @return String the URL, or a null string if this is an
1027          *  interwiki link
1028          */
1029         public function getEditURL() {
1030                 if ( $this->mInterwiki != '' ) {
1031                         return '';
1032                 }
1033                 $s = $this->getLocalURL( 'action=edit' );
1034
1035                 return $s;
1036         }
1037
1038         /**
1039          * Get the HTML-escaped displayable text form.
1040          * Used for the title field in <a> tags.
1041          *
1042          * @return String the text, including any prefixes
1043          */
1044         public function getEscapedText() {
1045                 return htmlspecialchars( $this->getPrefixedText() );
1046         }
1047
1048         /**
1049          * Is this Title interwiki?
1050          *
1051          * @return Bool
1052          */
1053         public function isExternal() {
1054                 return ( $this->mInterwiki != '' );
1055         }
1056
1057         /**
1058          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1059          *
1060          * @param $action String Action to check (default: edit)
1061          * @return Bool
1062          */
1063         public function isSemiProtected( $action = 'edit' ) {
1064                 if ( $this->exists() ) {
1065                         $restrictions = $this->getRestrictions( $action );
1066                         if ( count( $restrictions ) > 0 ) {
1067                                 foreach ( $restrictions as $restriction ) {
1068                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1069                                                 return false;
1070                                         }
1071                                 }
1072                         } else {
1073                                 # Not protected
1074                                 return false;
1075                         }
1076                         return true;
1077                 } else {
1078                         # If it doesn't exist, it can't be protected
1079                         return false;
1080                 }
1081         }
1082
1083         /**
1084          * Does the title correspond to a protected article?
1085          *
1086          * @param $action String the action the page is protected from,
1087          * by default checks all actions.
1088          * @return Bool
1089          */
1090         public function isProtected( $action = '' ) {
1091                 global $wgRestrictionLevels;
1092
1093                 $restrictionTypes = $this->getRestrictionTypes();
1094
1095                 # Special pages have inherent protection
1096                 if( $this->getNamespace() == NS_SPECIAL ) {
1097                         return true;
1098                 }
1099
1100                 # Check regular protection levels
1101                 foreach ( $restrictionTypes as $type ) {
1102                         if ( $action == $type || $action == '' ) {
1103                                 $r = $this->getRestrictions( $type );
1104                                 foreach ( $wgRestrictionLevels as $level ) {
1105                                         if ( in_array( $level, $r ) && $level != '' ) {
1106                                                 return true;
1107                                         }
1108                                 }
1109                         }
1110                 }
1111
1112                 return false;
1113         }
1114
1115         /**
1116          * Is this a conversion table for the LanguageConverter?
1117          *
1118          * @return Bool
1119          */
1120         public function isConversionTable() {
1121                 if(
1122                         $this->getNamespace() == NS_MEDIAWIKI &&
1123                         strpos( $this->getText(), 'Conversiontable' ) !== false
1124                 )
1125                 {
1126                         return true;
1127                 }
1128
1129                 return false;
1130         }
1131
1132         /**
1133          * Is $wgUser watching this page?
1134          *
1135          * @return Bool
1136          */
1137         public function userIsWatching() {
1138                 global $wgUser;
1139
1140                 if ( is_null( $this->mWatched ) ) {
1141                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1142                                 $this->mWatched = false;
1143                         } else {
1144                                 $this->mWatched = $wgUser->isWatched( $this );
1145                         }
1146                 }
1147                 return $this->mWatched;
1148         }
1149
1150         /**
1151          * Can $wgUser perform $action on this page?
1152          * This skips potentially expensive cascading permission checks
1153          * as well as avoids expensive error formatting
1154          *
1155          * Suitable for use for nonessential UI controls in common cases, but
1156          * _not_ for functional access control.
1157          *
1158          * May provide false positives, but should never provide a false negative.
1159          *
1160          * @param $action String action that permission needs to be checked for
1161          * @return Bool
1162          */
1163         public function quickUserCan( $action ) {
1164                 return $this->userCan( $action, false );
1165         }
1166
1167         /**
1168          * Determines if $user is unable to edit this page because it has been protected
1169          * by $wgNamespaceProtection.
1170          *
1171          * @param $user User object to check permissions
1172          * @return Bool
1173          */
1174         public function isNamespaceProtected( User $user ) {
1175                 global $wgNamespaceProtection;
1176
1177                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1178                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1179                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1180                                         return true;
1181                                 }
1182                         }
1183                 }
1184                 return false;
1185         }
1186
1187         /**
1188          * Can $wgUser perform $action on this page?
1189          *
1190          * @param $action String action that permission needs to be checked for
1191          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1192          * @return Bool
1193          */
1194         public function userCan( $action, $doExpensiveQueries = true ) {
1195                 global $wgUser;
1196                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1197         }
1198
1199         /**
1200          * Can $user perform $action on this page?
1201          *
1202          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1203          *
1204          * @param $action String action that permission needs to be checked for
1205          * @param $user User to check
1206          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1207          *   skipping checks for cascading protections and user blocks.
1208          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1209          * @return Array of arguments to wfMsg to explain permissions problems.
1210          */
1211         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1212                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1213
1214                 // Remove the errors being ignored.
1215                 foreach ( $errors as $index => $error ) {
1216                         $error_key = is_array( $error ) ? $error[0] : $error;
1217
1218                         if ( in_array( $error_key, $ignoreErrors ) ) {
1219                                 unset( $errors[$index] );
1220                         }
1221                 }
1222
1223                 return $errors;
1224         }
1225
1226         /**
1227          * Permissions checks that fail most often, and which are easiest to test.
1228          *
1229          * @param $action String the action to check
1230          * @param $user User user to check
1231          * @param $errors Array list of current errors
1232          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1233          * @param $short Boolean short circuit on first error
1234          *
1235          * @return Array list of errors
1236          */
1237         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1238                 $ns = $this->getNamespace();
1239
1240                 if ( $action == 'create' ) {
1241                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1242                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1243                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1244                         }
1245                 } elseif ( $action == 'move' ) {
1246                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1247                                         && $ns == NS_USER && !$this->isSubpage() ) {
1248                                 // Show user page-specific message only if the user can move other pages
1249                                 $errors[] = array( 'cant-move-user-page' );
1250                         }
1251
1252                         // Check if user is allowed to move files if it's a file
1253                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1254                                 $errors[] = array( 'movenotallowedfile' );
1255                         }
1256
1257                         if ( !$user->isAllowed( 'move', $ns) ) {
1258                                 // User can't move anything
1259
1260                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1261                                         array( 'user' ), $ns ), true );
1262                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1263                                         array( 'autoconfirmed' ), $ns ), true );
1264
1265                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1266                                         // custom message if logged-in users without any special rights can move
1267                                         $errors[] = array( 'movenologintext' );
1268                                 } else {
1269                                         $errors[] = array( 'movenotallowed' );
1270                                 }
1271                         }
1272                 } elseif ( $action == 'move-target' ) {
1273                         if ( !$user->isAllowed( 'move', $ns ) ) {
1274                                 // User can't move anything
1275                                 $errors[] = array( 'movenotallowed' );
1276                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1277                                         && $ns == NS_USER && !$this->isSubpage() ) {
1278                                 // Show user page-specific message only if the user can move other pages
1279                                 $errors[] = array( 'cant-move-to-user-page' );
1280                         }
1281                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1282                         // We avoid expensive display logic for quickUserCan's and such
1283                         $groups = false;
1284                         if ( !$short ) {
1285                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1286                                         User::getGroupsWithPermission( $action, $ns ) );
1287                         }
1288
1289                         if ( $groups ) {
1290                                 global $wgLang;
1291                                 $return = array(
1292                                         'badaccess-groups',
1293                                         $wgLang->commaList( $groups ),
1294                                         count( $groups )
1295                                 );
1296                         } else {
1297                                 $return = array( 'badaccess-group0' );
1298                         }
1299                         $errors[] = $return;
1300                 }
1301
1302                 return $errors;
1303         }
1304
1305         /**
1306          * Add the resulting error code to the errors array
1307          *
1308          * @param $errors Array list of current errors
1309          * @param $result Mixed result of errors
1310          *
1311          * @return Array list of errors
1312          */
1313         private function resultToError( $errors, $result ) {
1314                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1315                         // A single array representing an error
1316                         $errors[] = $result;
1317                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1318                         // A nested array representing multiple errors
1319                         $errors = array_merge( $errors, $result );
1320                 } elseif ( $result !== '' && is_string( $result ) ) {
1321                         // A string representing a message-id
1322                         $errors[] = array( $result );
1323                 } elseif ( $result === false ) {
1324                         // a generic "We don't want them to do that"
1325                         $errors[] = array( 'badaccess-group0' );
1326                 }
1327                 return $errors;
1328         }
1329
1330         /**
1331          * Check various permission hooks
1332          *
1333          * @param $action String the action to check
1334          * @param $user User user to check
1335          * @param $errors Array list of current errors
1336          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1337          * @param $short Boolean short circuit on first error
1338          *
1339          * @return Array list of errors
1340          */
1341         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1342                 // Use getUserPermissionsErrors instead
1343                 $result = '';
1344                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1345                         return $result ? array() : array( array( 'badaccess-group0' ) );
1346                 }
1347                 // Check getUserPermissionsErrors hook
1348                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1349                         $errors = $this->resultToError( $errors, $result );
1350                 }
1351                 // Check getUserPermissionsErrorsExpensive hook
1352                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1353                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1354                         $errors = $this->resultToError( $errors, $result );
1355                 }
1356
1357                 return $errors;
1358         }
1359
1360         /**
1361          * Check permissions on special pages & namespaces
1362          *
1363          * @param $action String the action to check
1364          * @param $user User user to check
1365          * @param $errors Array list of current errors
1366          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1367          * @param $short Boolean short circuit on first error
1368          *
1369          * @return Array list of errors
1370          */
1371         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1372                 # Only 'createaccount' and 'execute' can be performed on
1373                 # special pages, which don't actually exist in the DB.
1374                 $specialOKActions = array( 'createaccount', 'execute' );
1375                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1376                         $errors[] = array( 'ns-specialprotected' );
1377                 }
1378
1379                 # Check $wgNamespaceProtection for restricted namespaces
1380                 if ( $this->isNamespaceProtected( $user ) ) {
1381                         $ns = $this->mNamespace == NS_MAIN ?
1382                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1383                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1384                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1385                 }
1386
1387                 return $errors;
1388         }
1389
1390         /**
1391          * Check CSS/JS sub-page permissions
1392          *
1393          * @param $action String the action to check
1394          * @param $user User user to check
1395          * @param $errors Array list of current errors
1396          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1397          * @param $short Boolean short circuit on first error
1398          *
1399          * @return Array list of errors
1400          */
1401         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1402                 # Protect css/js subpages of user pages
1403                 # XXX: this might be better using restrictions
1404                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1405                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1406                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1407                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1408                                 $errors[] = array( 'customcssprotected' );
1409                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1410                                 $errors[] = array( 'customjsprotected' );
1411                         }
1412                 }
1413
1414                 return $errors;
1415         }
1416
1417         /**
1418          * Check against page_restrictions table requirements on this
1419          * page. The user must possess all required rights for this
1420          * action.
1421          *
1422          * @param $action String the action to check
1423          * @param $user User user to check
1424          * @param $errors Array list of current errors
1425          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1426          * @param $short Boolean short circuit on first error
1427          *
1428          * @return Array list of errors
1429          */
1430         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1431                 foreach ( $this->getRestrictions( $action ) as $right ) {
1432                         // Backwards compatibility, rewrite sysop -> protect
1433                         if ( $right == 'sysop' ) {
1434                                 $right = 'protect';
1435                         }
1436                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1437                                 // Users with 'editprotected' permission can edit protected pages
1438                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected', $this->mNamespace ) ) {
1439                                         // Users with 'editprotected' permission cannot edit protected pages
1440                                         // with cascading option turned on.
1441                                         if ( $this->mCascadeRestriction ) {
1442                                                 $errors[] = array( 'protectedpagetext', $right );
1443                                         }
1444                                 } else {
1445                                         $errors[] = array( 'protectedpagetext', $right );
1446                                 }
1447                         }
1448                 }
1449
1450                 return $errors;
1451         }
1452
1453         /**
1454          * Check restrictions on cascading pages.
1455          *
1456          * @param $action String the action to check
1457          * @param $user User to check
1458          * @param $errors Array list of current errors
1459          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1460          * @param $short Boolean short circuit on first error
1461          *
1462          * @return Array list of errors
1463          */
1464         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1465                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1466                         # We /could/ use the protection level on the source page, but it's
1467                         # fairly ugly as we have to establish a precedence hierarchy for pages
1468                         # included by multiple cascade-protected pages. So just restrict
1469                         # it to people with 'protect' permission, as they could remove the
1470                         # protection anyway.
1471                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1472                         # Cascading protection depends on more than this page...
1473                         # Several cascading protected pages may include this page...
1474                         # Check each cascading level
1475                         # This is only for protection restrictions, not for all actions
1476                         if ( isset( $restrictions[$action] ) ) {
1477                                 foreach ( $restrictions[$action] as $right ) {
1478                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1479                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1480                                                 $pages = '';
1481                                                 foreach ( $cascadingSources as $page )
1482                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1483                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1484                                         }
1485                                 }
1486                         }
1487                 }
1488
1489                 return $errors;
1490         }
1491
1492         /**
1493          * Check action permissions not already checked in checkQuickPermissions
1494          *
1495          * @param $action String the action to check
1496          * @param $user User to check
1497          * @param $errors Array list of current errors
1498          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1499          * @param $short Boolean short circuit on first error
1500          *
1501          * @return Array list of errors
1502          */
1503         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1504                 if ( $action == 'protect' ) {
1505                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1506                                 // If they can't edit, they shouldn't protect.
1507                                 $errors[] = array( 'protect-cantedit' );
1508                         }
1509                 } elseif ( $action == 'create' ) {
1510                         $title_protection = $this->getTitleProtection();
1511                         if( $title_protection ) {
1512                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1513                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1514                                 }
1515                                 if( $title_protection['pt_create_perm'] == '' ||
1516                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1517                                                 $this->mNamespace ) ) {
1518                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1519                                 }
1520                         }
1521                 } elseif ( $action == 'move' ) {
1522                         // Check for immobile pages
1523                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1524                                 // Specific message for this case
1525                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1526                         } elseif ( !$this->isMovable() ) {
1527                                 // Less specific message for rarer cases
1528                                 $errors[] = array( 'immobile-page' );
1529                         }
1530                 } elseif ( $action == 'move-target' ) {
1531                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1532                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1533                         } elseif ( !$this->isMovable() ) {
1534                                 $errors[] = array( 'immobile-target-page' );
1535                         }
1536                 }
1537                 return $errors;
1538         }
1539
1540         /**
1541          * Check that the user isn't blocked from editting.
1542          *
1543          * @param $action String the action to check
1544          * @param $user User to check
1545          * @param $errors Array list of current errors
1546          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1547          * @param $short Boolean short circuit on first error
1548          *
1549          * @return Array list of errors
1550          */
1551         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1552                 if( !$doExpensiveQueries ) {
1553                         return $errors;
1554                 }
1555
1556                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1557
1558                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1559                         $errors[] = array( 'confirmedittext' );
1560                 }
1561
1562                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1563                         // Edit blocks should not affect reading.
1564                         // Account creation blocks handled at userlogin.
1565                         // Unblocking handled in SpecialUnblock
1566                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1567                         // Don't block the user from editing their own talk page unless they've been
1568                         // explicitly blocked from that too.
1569                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1570                         $block = $user->mBlock;
1571
1572                         // This is from OutputPage::blockedPage
1573                         // Copied at r23888 by werdna
1574
1575                         $id = $user->blockedBy();
1576                         $reason = $user->blockedFor();
1577                         if ( $reason == '' ) {
1578                                 $reason = wfMsg( 'blockednoreason' );
1579                         }
1580                         $ip = wfGetIP();
1581
1582                         if ( is_numeric( $id ) ) {
1583                                 $name = User::whoIs( $id );
1584                         } else {
1585                                 $name = $id;
1586                         }
1587
1588                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1589                         $blockid = $block->getId();
1590                         $blockExpiry = $user->mBlock->mExpiry;
1591                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1592                         if ( $blockExpiry == 'infinity' ) {
1593                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1594                         } else {
1595                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1596                         }
1597
1598                         $intended = strval( $user->mBlock->getTarget() );
1599
1600                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1601                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1602                 }
1603
1604                 return $errors;
1605         }
1606
1607         /**
1608          * Can $user perform $action on this page? This is an internal function,
1609          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1610          * checks on wfReadOnly() and blocks)
1611          *
1612          * @param $action String action that permission needs to be checked for
1613          * @param $user User to check
1614          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1615          * @param $short Bool Set this to true to stop after the first permission error.
1616          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1617          */
1618         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1619                 wfProfileIn( __METHOD__ );
1620
1621                 $errors = array();
1622                 $checks = array(
1623                         'checkQuickPermissions',
1624                         'checkPermissionHooks',
1625                         'checkSpecialsAndNSPermissions',
1626                         'checkCSSandJSPermissions',
1627                         'checkPageRestrictions',
1628                         'checkCascadingSourcesRestrictions',
1629                         'checkActionPermissions',
1630                         'checkUserBlock'
1631                 );
1632
1633                 while( count( $checks ) > 0 &&
1634                            !( $short && count( $errors ) > 0 ) ) {
1635                         $method = array_shift( $checks );
1636                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1637                 }
1638
1639                 wfProfileOut( __METHOD__ );
1640                 return $errors;
1641         }
1642
1643         /**
1644          * Is this title subject to title protection?
1645          * Title protection is the one applied against creation of such title.
1646          *
1647          * @return Mixed An associative array representing any existent title
1648          *   protection, or false if there's none.
1649          */
1650         private function getTitleProtection() {
1651                 // Can't protect pages in special namespaces
1652                 if ( $this->getNamespace() < 0 ) {
1653                         return false;
1654                 }
1655
1656                 // Can't protect pages that exist.
1657                 if ( $this->exists() ) {
1658                         return false;
1659                 }
1660
1661                 if ( !isset( $this->mTitleProtection ) ) {
1662                         $dbr = wfGetDB( DB_SLAVE );
1663                         $res = $dbr->select( 'protected_titles', '*',
1664                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1665                                 __METHOD__ );
1666
1667                         // fetchRow returns false if there are no rows.
1668                         $this->mTitleProtection = $dbr->fetchRow( $res );
1669                 }
1670                 return $this->mTitleProtection;
1671         }
1672
1673         /**
1674          * Update the title protection status
1675          *
1676          * @param $create_perm String Permission required for creation
1677          * @param $reason String Reason for protection
1678          * @param $expiry String Expiry timestamp
1679          * @return boolean true
1680          */
1681         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1682                 global $wgUser, $wgContLang;
1683
1684                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1685                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1686                         // No change
1687                         return true;
1688                 }
1689
1690                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1691
1692                 $dbw = wfGetDB( DB_MASTER );
1693
1694                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1695
1696                 $expiry_description = '';
1697                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1698                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1699                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1700                 } else {
1701                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1702                 }
1703
1704                 # Update protection table
1705                 if ( $create_perm != '' ) {
1706                         $this->mTitleProtection = array(
1707                                         'pt_namespace' => $namespace,
1708                                         'pt_title' => $title,
1709                                         'pt_create_perm' => $create_perm,
1710                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1711                                         'pt_expiry' => $encodedExpiry,
1712                                         'pt_user' => $wgUser->getId(),
1713                                         'pt_reason' => $reason,
1714                                 );
1715                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1716                                 $this->mTitleProtection, __METHOD__     );
1717                 } else {
1718                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1719                                 'pt_title' => $title ), __METHOD__ );
1720                         $this->mTitleProtection = false;
1721                 }
1722
1723                 # Update the protection log
1724                 if ( $dbw->affectedRows() ) {
1725                         $log = new LogPage( 'protect' );
1726
1727                         if ( $create_perm ) {
1728                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1729                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1730                         } else {
1731                                 $log->addEntry( 'unprotect', $this, $reason );
1732                         }
1733                 }
1734
1735                 return true;
1736         }
1737
1738         /**
1739          * Remove any title protection due to page existing
1740          */
1741         public function deleteTitleProtection() {
1742                 $dbw = wfGetDB( DB_MASTER );
1743
1744                 $dbw->delete(
1745                         'protected_titles',
1746                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1747                         __METHOD__
1748                 );
1749                 $this->mTitleProtection = false;
1750         }
1751
1752         /**
1753          * Would anybody with sufficient privileges be able to move this page?
1754          * Some pages just aren't movable.
1755          *
1756          * @return Bool TRUE or FALSE
1757          */
1758         public function isMovable() {
1759                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1760         }
1761
1762         /**
1763          * Can $wgUser read this page?
1764          *
1765          * @return Bool
1766          * @todo fold these checks into userCan()
1767          */
1768         public function userCanRead() {
1769                 global $wgUser, $wgGroupPermissions;
1770
1771                 static $useShortcut = null;
1772
1773                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1774                 if ( is_null( $useShortcut ) ) {
1775                         global $wgRevokePermissions;
1776                         $useShortcut = true;
1777                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1778                                 # Not a public wiki, so no shortcut
1779                                 $useShortcut = false;
1780                         } elseif ( !empty( $wgRevokePermissions ) ) {
1781                                 /**
1782                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1783                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1784                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1785                                  * reading is allowed.
1786                                  */
1787                                 foreach ( $wgRevokePermissions as $perms ) {
1788                                         if ( !empty( $perms['read'] ) ) {
1789                                                 # We might be removing the read right from the user, so no shortcut
1790                                                 $useShortcut = false;
1791                                                 break;
1792                                         }
1793                                 }
1794                         }
1795                 }
1796
1797                 $result = null;
1798                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1799                 if ( $result !== null ) {
1800                         return $result;
1801                 }
1802
1803                 # Shortcut for public wikis, allows skipping quite a bit of code
1804                 if ( $useShortcut ) {
1805                         return true;
1806                 }
1807
1808                 if ( $wgUser->isAllowed( 'read' ) ) {
1809                         return true;
1810                 } else {
1811                         global $wgWhitelistRead;
1812
1813                         # Always grant access to the login page.
1814                         # Even anons need to be able to log in.
1815                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1816                                 return true;
1817                         }
1818
1819                         # Bail out if there isn't whitelist
1820                         if ( !is_array( $wgWhitelistRead ) ) {
1821                                 return false;
1822                         }
1823
1824                         # Check for explicit whitelisting
1825                         $name = $this->getPrefixedText();
1826                         $dbName = $this->getPrefixedDBKey();
1827                         // Check with and without underscores
1828                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1829                                 return true;
1830
1831                         # Old settings might have the title prefixed with
1832                         # a colon for main-namespace pages
1833                         if ( $this->getNamespace() == NS_MAIN ) {
1834                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1835                                         return true;
1836                                 }
1837                         }
1838
1839                         # If it's a special page, ditch the subpage bit and check again
1840                         if ( $this->getNamespace() == NS_SPECIAL ) {
1841                                 $name = $this->getDBkey();
1842                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1843                                 if ( $name === false ) {
1844                                         # Invalid special page, but we show standard login required message
1845                                         return false;
1846                                 }
1847
1848                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1849                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1850                                         return true;
1851                                 }
1852                         }
1853
1854                 }
1855                 return false;
1856         }
1857
1858         /**
1859          * Is this the mainpage?
1860          * @note Title::newFromText seams to be sufficiently optimized by the title
1861          * cache that we don't need to over-optimize by doing direct comparisons and
1862          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1863          * ends up reporting something differently than $title->isMainPage();
1864          *
1865          * @return Bool
1866          */
1867         public function isMainPage() {
1868                 return $this->equals( Title::newMainPage() );
1869         }
1870
1871         /**
1872          * Is this a talk page of some sort?
1873          *
1874          * @return Bool
1875          */
1876         public function isTalkPage() {
1877                 return MWNamespace::isTalk( $this->getNamespace() );
1878         }
1879
1880         /**
1881          * Is this a subpage?
1882          *
1883          * @return Bool
1884          */
1885         public function isSubpage() {
1886                 return MWNamespace::hasSubpages( $this->mNamespace )
1887                         ? strpos( $this->getText(), '/' ) !== false
1888                         : false;
1889         }
1890
1891         /**
1892          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1893          *
1894          * @return Bool
1895          */
1896         public function hasSubpages() {
1897                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1898                         # Duh
1899                         return false;
1900                 }
1901
1902                 # We dynamically add a member variable for the purpose of this method
1903                 # alone to cache the result.  There's no point in having it hanging
1904                 # around uninitialized in every Title object; therefore we only add it
1905                 # if needed and don't declare it statically.
1906                 if ( isset( $this->mHasSubpages ) ) {
1907                         return $this->mHasSubpages;
1908                 }
1909
1910                 $subpages = $this->getSubpages( 1 );
1911                 if ( $subpages instanceof TitleArray ) {
1912                         return $this->mHasSubpages = (bool)$subpages->count();
1913                 }
1914                 return $this->mHasSubpages = false;
1915         }
1916
1917         /**
1918          * Get all subpages of this page.
1919          *
1920          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1921          * @return mixed TitleArray, or empty array if this page's namespace
1922          *  doesn't allow subpages
1923          */
1924         public function getSubpages( $limit = -1 ) {
1925                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1926                         return array();
1927                 }
1928
1929                 $dbr = wfGetDB( DB_SLAVE );
1930                 $conds['page_namespace'] = $this->getNamespace();
1931                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1932                 $options = array();
1933                 if ( $limit > -1 ) {
1934                         $options['LIMIT'] = $limit;
1935                 }
1936                 return $this->mSubpages = TitleArray::newFromResult(
1937                         $dbr->select( 'page',
1938                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1939                                 $conds,
1940                                 __METHOD__,
1941                                 $options
1942                         )
1943                 );
1944         }
1945
1946         /**
1947          * Does that page contain wikitext, or it is JS, CSS or whatever?
1948          *
1949          * @return Bool
1950          */
1951         public function isWikitextPage() {
1952                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
1953                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
1954                 return $retval;
1955         }
1956
1957         /**
1958          * Could this page contain custom CSS or JavaScript, based
1959          * on the title?
1960          *
1961          * @return Bool
1962          */
1963         public function isCssOrJsPage() {
1964                 $retval = $this->mNamespace == NS_MEDIAWIKI
1965                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1966                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
1967                 return $retval;
1968         }
1969
1970         /**
1971          * Is this a .css or .js subpage of a user page?
1972          * @return Bool
1973          */
1974         public function isCssJsSubpage() {
1975                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1976         }
1977
1978         /**
1979          * Is this a *valid* .css or .js subpage of a user page?
1980          *
1981          * @return Bool
1982          * @deprecated since 1.17
1983          */
1984         public function isValidCssJsSubpage() {
1985                 return $this->isCssJsSubpage();
1986         }
1987
1988         /**
1989          * Trim down a .css or .js subpage title to get the corresponding skin name
1990          *
1991          * @return string containing skin name from .css or .js subpage title
1992          */
1993         public function getSkinFromCssJsSubpage() {
1994                 $subpage = explode( '/', $this->mTextform );
1995                 $subpage = $subpage[ count( $subpage ) - 1 ];
1996                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1997         }
1998
1999         /**
2000          * Is this a .css subpage of a user page?
2001          *
2002          * @return Bool
2003          */
2004         public function isCssSubpage() {
2005                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2006         }
2007
2008         /**
2009          * Is this a .js subpage of a user page?
2010          *
2011          * @return Bool
2012          */
2013         public function isJsSubpage() {
2014                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2015         }
2016
2017         /**
2018          * Protect css subpages of user pages: can $wgUser edit
2019          * this page?
2020          *
2021          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2022          * @return Bool
2023          */
2024         public function userCanEditCssSubpage() {
2025                 global $wgUser;
2026                 wfDeprecated( __METHOD__ );
2027                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2028                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2029         }
2030
2031         /**
2032          * Protect js subpages of user pages: can $wgUser edit
2033          * this page?
2034          *
2035          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2036          * @return Bool
2037          */
2038         public function userCanEditJsSubpage() {
2039                 global $wgUser;
2040                 wfDeprecated( __METHOD__ );
2041                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2042                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2043         }
2044
2045         /**
2046          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2047          *
2048          * @return Bool If the page is subject to cascading restrictions.
2049          */
2050         public function isCascadeProtected() {
2051                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2052                 return ( $sources > 0 );
2053         }
2054
2055         /**
2056          * Cascading protection: Get the source of any cascading restrictions on this page.
2057          *
2058          * @param $getPages Bool Whether or not to retrieve the actual pages
2059          *        that the restrictions have come from.
2060          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2061          *     have come, false for none, or true if such restrictions exist, but $getPages
2062          *     was not set.  The restriction array is an array of each type, each of which
2063          *     contains a array of unique groups.
2064          */
2065         public function getCascadeProtectionSources( $getPages = true ) {
2066                 global $wgContLang;
2067                 $pagerestrictions = array();
2068
2069                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2070                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2071                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2072                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2073                 }
2074
2075                 wfProfileIn( __METHOD__ );
2076
2077                 $dbr = wfGetDB( DB_SLAVE );
2078
2079                 if ( $this->getNamespace() == NS_FILE ) {
2080                         $tables = array( 'imagelinks', 'page_restrictions' );
2081                         $where_clauses = array(
2082                                 'il_to' => $this->getDBkey(),
2083                                 'il_from=pr_page',
2084                                 'pr_cascade' => 1
2085                         );
2086                 } else {
2087                         $tables = array( 'templatelinks', 'page_restrictions' );
2088                         $where_clauses = array(
2089                                 'tl_namespace' => $this->getNamespace(),
2090                                 'tl_title' => $this->getDBkey(),
2091                                 'tl_from=pr_page',
2092                                 'pr_cascade' => 1
2093                         );
2094                 }
2095
2096                 if ( $getPages ) {
2097                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2098                                                    'pr_expiry', 'pr_type', 'pr_level' );
2099                         $where_clauses[] = 'page_id=pr_page';
2100                         $tables[] = 'page';
2101                 } else {
2102                         $cols = array( 'pr_expiry' );
2103                 }
2104
2105                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2106
2107                 $sources = $getPages ? array() : false;
2108                 $now = wfTimestampNow();
2109                 $purgeExpired = false;
2110
2111                 foreach ( $res as $row ) {
2112                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2113                         if ( $expiry > $now ) {
2114                                 if ( $getPages ) {
2115                                         $page_id = $row->pr_page;
2116                                         $page_ns = $row->page_namespace;
2117                                         $page_title = $row->page_title;
2118                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2119                                         # Add groups needed for each restriction type if its not already there
2120                                         # Make sure this restriction type still exists
2121
2122                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2123                                                 $pagerestrictions[$row->pr_type] = array();
2124                                         }
2125
2126                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2127                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2128                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2129                                         }
2130                                 } else {
2131                                         $sources = true;
2132                                 }
2133                         } else {
2134                                 // Trigger lazy purge of expired restrictions from the db
2135                                 $purgeExpired = true;
2136                         }
2137                 }
2138                 if ( $purgeExpired ) {
2139                         Title::purgeExpiredRestrictions();
2140                 }
2141
2142                 if ( $getPages ) {
2143                         $this->mCascadeSources = $sources;
2144                         $this->mCascadingRestrictions = $pagerestrictions;
2145                 } else {
2146                         $this->mHasCascadingRestrictions = $sources;
2147                 }
2148
2149                 wfProfileOut( __METHOD__ );
2150                 return array( $sources, $pagerestrictions );
2151         }
2152
2153         /**
2154          * Returns cascading restrictions for the current article
2155          *
2156          * @return Boolean
2157          */
2158         function areRestrictionsCascading() {
2159                 if ( !$this->mRestrictionsLoaded ) {
2160                         $this->loadRestrictions();
2161                 }
2162
2163                 return $this->mCascadeRestriction;
2164         }
2165
2166         /**
2167          * Loads a string into mRestrictions array
2168          *
2169          * @param $res Resource restrictions as an SQL result.
2170          * @param $oldFashionedRestrictions String comma-separated list of page
2171          *        restrictions from page table (pre 1.10)
2172          */
2173         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2174                 $rows = array();
2175
2176                 foreach ( $res as $row ) {
2177                         $rows[] = $row;
2178                 }
2179
2180                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2181         }
2182
2183         /**
2184          * Compiles list of active page restrictions from both page table (pre 1.10)
2185          * and page_restrictions table for this existing page.
2186          * Public for usage by LiquidThreads.
2187          *
2188          * @param $rows array of db result objects
2189          * @param $oldFashionedRestrictions string comma-separated list of page
2190          *        restrictions from page table (pre 1.10)
2191          */
2192         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2193                 global $wgContLang;
2194                 $dbr = wfGetDB( DB_SLAVE );
2195
2196                 $restrictionTypes = $this->getRestrictionTypes();
2197
2198                 foreach ( $restrictionTypes as $type ) {
2199                         $this->mRestrictions[$type] = array();
2200                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2201                 }
2202
2203                 $this->mCascadeRestriction = false;
2204
2205                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2206
2207                 if ( $oldFashionedRestrictions === null ) {
2208                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2209                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2210                 }
2211
2212                 if ( $oldFashionedRestrictions != '' ) {
2213
2214                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2215                                 $temp = explode( '=', trim( $restrict ) );
2216                                 if ( count( $temp ) == 1 ) {
2217                                         // old old format should be treated as edit/move restriction
2218                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2219                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2220                                 } else {
2221                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2222                                 }
2223                         }
2224
2225                         $this->mOldRestrictions = true;
2226
2227                 }
2228
2229                 if ( count( $rows ) ) {
2230                         # Current system - load second to make them override.
2231                         $now = wfTimestampNow();
2232                         $purgeExpired = false;
2233
2234                         # Cycle through all the restrictions.
2235                         foreach ( $rows as $row ) {
2236
2237                                 // Don't take care of restrictions types that aren't allowed
2238                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2239                                         continue;
2240
2241                                 // This code should be refactored, now that it's being used more generally,
2242                                 // But I don't really see any harm in leaving it in Block for now -werdna
2243                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2244
2245                                 // Only apply the restrictions if they haven't expired!
2246                                 if ( !$expiry || $expiry > $now ) {
2247                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2248                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2249
2250                                         $this->mCascadeRestriction |= $row->pr_cascade;
2251                                 } else {
2252                                         // Trigger a lazy purge of expired restrictions
2253                                         $purgeExpired = true;
2254                                 }
2255                         }
2256
2257                         if ( $purgeExpired ) {
2258                                 Title::purgeExpiredRestrictions();
2259                         }
2260                 }
2261
2262                 $this->mRestrictionsLoaded = true;
2263         }
2264
2265         /**
2266          * Load restrictions from the page_restrictions table
2267          *
2268          * @param $oldFashionedRestrictions String comma-separated list of page
2269          *        restrictions from page table (pre 1.10)
2270          */
2271         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2272                 global $wgContLang;
2273                 if ( !$this->mRestrictionsLoaded ) {
2274                         if ( $this->exists() ) {
2275                                 $dbr = wfGetDB( DB_SLAVE );
2276
2277                                 $res = $dbr->select(
2278                                         'page_restrictions',
2279                                         '*',
2280                                         array( 'pr_page' => $this->getArticleId() ),
2281                                         __METHOD__
2282                                 );
2283
2284                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2285                         } else {
2286                                 $title_protection = $this->getTitleProtection();
2287
2288                                 if ( $title_protection ) {
2289                                         $now = wfTimestampNow();
2290                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2291
2292                                         if ( !$expiry || $expiry > $now ) {
2293                                                 // Apply the restrictions
2294                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2295                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2296                                         } else { // Get rid of the old restrictions
2297                                                 Title::purgeExpiredRestrictions();
2298                                                 $this->mTitleProtection = false;
2299                                         }
2300                                 } else {
2301                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2302                                 }
2303                                 $this->mRestrictionsLoaded = true;
2304                         }
2305                 }
2306         }
2307
2308         /**
2309          * Purge expired restrictions from the page_restrictions table
2310          */
2311         static function purgeExpiredRestrictions() {
2312                 $dbw = wfGetDB( DB_MASTER );
2313                 $dbw->delete(
2314                         'page_restrictions',
2315                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2316                         __METHOD__
2317                 );
2318
2319                 $dbw->delete(
2320                         'protected_titles',
2321                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2322                         __METHOD__
2323                 );
2324         }
2325
2326         /**
2327          * Accessor/initialisation for mRestrictions
2328          *
2329          * @param $action String action that permission needs to be checked for
2330          * @return Array of Strings the array of groups allowed to edit this article
2331          */
2332         public function getRestrictions( $action ) {
2333                 if ( !$this->mRestrictionsLoaded ) {
2334                         $this->loadRestrictions();
2335                 }
2336                 return isset( $this->mRestrictions[$action] )
2337                                 ? $this->mRestrictions[$action]
2338                                 : array();
2339         }
2340
2341         /**
2342          * Get the expiry time for the restriction against a given action
2343          *
2344          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2345          *      or not protected at all, or false if the action is not recognised.
2346          */
2347         public function getRestrictionExpiry( $action ) {
2348                 if ( !$this->mRestrictionsLoaded ) {
2349                         $this->loadRestrictions();
2350                 }
2351                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2352         }
2353
2354         /**
2355          * Is there a version of this page in the deletion archive?
2356          *
2357          * @param $includeSuppressed Boolean Include suppressed revisions?
2358          * @return Int the number of archived revisions
2359          */
2360         public function isDeleted( $includeSuppressed = false ) {
2361                 if ( $this->getNamespace() < 0 ) {
2362                         $n = 0;
2363                 } else {
2364                         $dbr = wfGetDB( DB_SLAVE );
2365                         $conditions = array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() );
2366
2367                         if( !$includeSuppressed ) {
2368                                 $suppressedTextBits = Revision::DELETED_TEXT | Revision::DELETED_RESTRICTED;
2369                                 $conditions[] = $dbr->bitAnd('ar_deleted', $suppressedTextBits ) .
2370                                 ' != ' . $suppressedTextBits;
2371                         }
2372
2373                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2374                                 $conditions,
2375                                 __METHOD__
2376                         );
2377                         if ( $this->getNamespace() == NS_FILE ) {
2378                                 $fconditions = array( 'fa_name' => $this->getDBkey() );
2379                                 if( !$includeSuppressed ) {
2380                                         $suppressedTextBits = File::DELETED_FILE | File::DELETED_RESTRICTED;
2381                                         $fconditions[] = $dbr->bitAnd('fa_deleted', $suppressedTextBits ) .
2382                                         ' != ' . $suppressedTextBits;
2383                                 }
2384
2385                                 $n += $dbr->selectField( 'filearchive',
2386                                         'COUNT(*)',
2387                                         $fconditions,
2388                                         __METHOD__
2389                                 );
2390                         }
2391                 }
2392                 return (int)$n;
2393         }
2394
2395         /**
2396          * Is there a version of this page in the deletion archive?
2397          *
2398          * @return Boolean
2399          */
2400         public function isDeletedQuick() {
2401                 if ( $this->getNamespace() < 0 ) {
2402                         return false;
2403                 }
2404                 $dbr = wfGetDB( DB_SLAVE );
2405                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2406                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2407                         __METHOD__
2408                 );
2409                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2410                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2411                                 array( 'fa_name' => $this->getDBkey() ),
2412                                 __METHOD__
2413                         );
2414                 }
2415                 return $deleted;
2416         }
2417
2418         /**
2419          * Get the article ID for this Title from the link cache,
2420          * adding it if necessary
2421          *
2422          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2423          *  for update
2424          * @return Int the ID
2425          */
2426         public function getArticleID( $flags = 0 ) {
2427                 if ( $this->getNamespace() < 0 ) {
2428                         return $this->mArticleID = 0;
2429                 }
2430                 $linkCache = LinkCache::singleton();
2431                 if ( $flags & self::GAID_FOR_UPDATE ) {
2432                         $oldUpdate = $linkCache->forUpdate( true );
2433                         $linkCache->clearLink( $this );
2434                         $this->mArticleID = $linkCache->addLinkObj( $this );
2435                         $linkCache->forUpdate( $oldUpdate );
2436                 } else {
2437                         if ( -1 == $this->mArticleID ) {
2438                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2439                         }
2440                 }
2441                 return $this->mArticleID;
2442         }
2443
2444         /**
2445          * Is this an article that is a redirect page?
2446          * Uses link cache, adding it if necessary
2447          *
2448          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2449          * @return Bool
2450          */
2451         public function isRedirect( $flags = 0 ) {
2452                 if ( !is_null( $this->mRedirect ) ) {
2453                         return $this->mRedirect;
2454                 }
2455                 # Calling getArticleID() loads the field from cache as needed
2456                 if ( !$this->getArticleID( $flags ) ) {
2457                         return $this->mRedirect = false;
2458                 }
2459                 $linkCache = LinkCache::singleton();
2460                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2461
2462                 return $this->mRedirect;
2463         }
2464
2465         /**
2466          * What is the length of this page?
2467          * Uses link cache, adding it if necessary
2468          *
2469          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2470          * @return Int
2471          */
2472         public function getLength( $flags = 0 ) {
2473                 if ( $this->mLength != -1 ) {
2474                         return $this->mLength;
2475                 }
2476                 # Calling getArticleID() loads the field from cache as needed
2477                 if ( !$this->getArticleID( $flags ) ) {
2478                         return $this->mLength = 0;
2479                 }
2480                 $linkCache = LinkCache::singleton();
2481                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2482
2483                 return $this->mLength;
2484         }
2485
2486         /**
2487          * What is the page_latest field for this page?
2488          *
2489          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2490          * @return Int or 0 if the page doesn't exist
2491          */
2492         public function getLatestRevID( $flags = 0 ) {
2493                 if ( $this->mLatestID !== false ) {
2494                         return intval( $this->mLatestID );
2495                 }
2496                 # Calling getArticleID() loads the field from cache as needed
2497                 if ( !$this->getArticleID( $flags ) ) {
2498                         return $this->mLatestID = 0;
2499                 }
2500                 $linkCache = LinkCache::singleton();
2501                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2502
2503                 return $this->mLatestID;
2504         }
2505
2506         /**
2507          * This clears some fields in this object, and clears any associated
2508          * keys in the "bad links" section of the link cache.
2509          *
2510          * - This is called from Article::doEdit() and Article::insertOn() to allow
2511          * loading of the new page_id. It's also called from
2512          * Article::doDeleteArticle()
2513          *
2514          * @param $newid Int the new Article ID
2515          */
2516         public function resetArticleID( $newid ) {
2517                 $linkCache = LinkCache::singleton();
2518                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2519
2520                 if ( $newid === false ) {
2521                         $this->mArticleID = -1;
2522                 } else {
2523                         $this->mArticleID = intval( $newid );
2524                 }
2525                 $this->mRestrictionsLoaded = false;
2526                 $this->mRestrictions = array();
2527                 $this->mRedirect = null;
2528                 $this->mLength = -1;
2529                 $this->mLatestID = false;
2530         }
2531
2532         /**
2533          * Updates page_touched for this page; called from LinksUpdate.php
2534          *
2535          * @return Bool true if the update succeded
2536          */
2537         public function invalidateCache() {
2538                 if ( wfReadOnly() ) {
2539                         return;
2540                 }
2541                 $dbw = wfGetDB( DB_MASTER );
2542                 $success = $dbw->update(
2543                         'page',
2544                         array( 'page_touched' => $dbw->timestamp() ),
2545                         $this->pageCond(),
2546                         __METHOD__
2547                 );
2548                 HTMLFileCache::clearFileCache( $this );
2549                 return $success;
2550         }
2551
2552         /**
2553          * Prefix some arbitrary text with the namespace or interwiki prefix
2554          * of this object
2555          *
2556          * @param $name String the text
2557          * @return String the prefixed text
2558          * @private
2559          */
2560         private function prefix( $name ) {
2561                 $p = '';
2562                 if ( $this->mInterwiki != '' ) {
2563                         $p = $this->mInterwiki . ':';
2564                 }
2565
2566                 if ( 0 != $this->mNamespace ) {
2567                         $p .= $this->getNsText() . ':';
2568                 }
2569                 return $p . $name;
2570         }
2571
2572         /**
2573          * Returns a simple regex that will match on characters and sequences invalid in titles.
2574          * Note that this doesn't pick up many things that could be wrong with titles, but that
2575          * replacing this regex with something valid will make many titles valid.
2576          *
2577          * @return String regex string
2578          */
2579         static function getTitleInvalidRegex() {
2580                 static $rxTc = false;
2581                 if ( !$rxTc ) {
2582                         # Matching titles will be held as illegal.
2583                         $rxTc = '/' .
2584                                 # Any character not allowed is forbidden...
2585                                 '[^' . Title::legalChars() . ']' .
2586                                 # URL percent encoding sequences interfere with the ability
2587                                 # to round-trip titles -- you can't link to them consistently.
2588                                 '|%[0-9A-Fa-f]{2}' .
2589                                 # XML/HTML character references produce similar issues.
2590                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2591                                 '|&#[0-9]+;' .
2592                                 '|&#x[0-9A-Fa-f]+;' .
2593                                 '/S';
2594                 }
2595
2596                 return $rxTc;
2597         }
2598
2599         /**
2600          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2601          *
2602          * @param $text String containing title to capitalize
2603          * @param $ns int namespace index, defaults to NS_MAIN
2604          * @return String containing capitalized title
2605          */
2606         public static function capitalize( $text, $ns = NS_MAIN ) {
2607                 global $wgContLang;
2608
2609                 if ( MWNamespace::isCapitalized( $ns ) ) {
2610                         return $wgContLang->ucfirst( $text );
2611                 } else {
2612                         return $text;
2613                 }
2614         }
2615
2616         /**
2617          * Secure and split - main initialisation function for this object
2618          *
2619          * Assumes that mDbkeyform has been set, and is urldecoded
2620          * and uses underscores, but not otherwise munged.  This function
2621          * removes illegal characters, splits off the interwiki and
2622          * namespace prefixes, sets the other forms, and canonicalizes
2623          * everything.
2624          *
2625          * @return Bool true on success
2626          */
2627         private function secureAndSplit() {
2628                 global $wgContLang, $wgLocalInterwiki;
2629
2630                 # Initialisation
2631                 $this->mInterwiki = $this->mFragment = '';
2632                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2633
2634                 $dbkey = $this->mDbkeyform;
2635
2636                 # Strip Unicode bidi override characters.
2637                 # Sometimes they slip into cut-n-pasted page titles, where the
2638                 # override chars get included in list displays.
2639                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2640
2641                 # Clean up whitespace
2642                 # Note: use of the /u option on preg_replace here will cause
2643                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2644                 # conveniently disabling them.
2645                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2646                 $dbkey = trim( $dbkey, '_' );
2647
2648                 if ( $dbkey == '' ) {
2649                         return false;
2650                 }
2651
2652                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2653                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2654                         return false;
2655                 }
2656
2657                 $this->mDbkeyform = $dbkey;
2658
2659                 # Initial colon indicates main namespace rather than specified default
2660                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2661                 if ( ':' == $dbkey[0] ) {
2662                         $this->mNamespace = NS_MAIN;
2663                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2664                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2665                 }
2666
2667                 # Namespace or interwiki prefix
2668                 $firstPass = true;
2669                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2670                 do {
2671                         $m = array();
2672                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2673                                 $p = $m[1];
2674                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2675                                         # Ordinary namespace
2676                                         $dbkey = $m[2];
2677                                         $this->mNamespace = $ns;
2678                                         # For Talk:X pages, check if X has a "namespace" prefix
2679                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2680                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2681                                                         # Disallow Talk:File:x type titles...
2682                                                         return false;
2683                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2684                                                         # Disallow Talk:Interwiki:x type titles...
2685                                                         return false;
2686                                                 }
2687                                         }
2688                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2689                                         if ( !$firstPass ) {
2690                                                 # Can't make a local interwiki link to an interwiki link.
2691                                                 # That's just crazy!
2692                                                 return false;
2693                                         }
2694
2695                                         # Interwiki link
2696                                         $dbkey = $m[2];
2697                                         $this->mInterwiki = $wgContLang->lc( $p );
2698
2699                                         # Redundant interwiki prefix to the local wiki
2700                                         if ( $wgLocalInterwiki !== false
2701                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2702                                         {
2703                                                 if ( $dbkey == '' ) {
2704                                                         # Can't have an empty self-link
2705                                                         return false;
2706                                                 }
2707                                                 $this->mInterwiki = '';
2708                                                 $firstPass = false;
2709                                                 # Do another namespace split...
2710                                                 continue;
2711                                         }
2712
2713                                         # If there's an initial colon after the interwiki, that also
2714                                         # resets the default namespace
2715                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2716                                                 $this->mNamespace = NS_MAIN;
2717                                                 $dbkey = substr( $dbkey, 1 );
2718                                         }
2719                                 }
2720                                 # If there's no recognized interwiki or namespace,
2721                                 # then let the colon expression be part of the title.
2722                         }
2723                         break;
2724                 } while ( true );
2725
2726                 # We already know that some pages won't be in the database!
2727                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2728                         $this->mArticleID = 0;
2729                 }
2730                 $fragment = strstr( $dbkey, '#' );
2731                 if ( false !== $fragment ) {
2732                         $this->setFragment( $fragment );
2733                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2734                         # remove whitespace again: prevents "Foo_bar_#"
2735                         # becoming "Foo_bar_"
2736                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2737                 }
2738
2739                 # Reject illegal characters.
2740                 $rxTc = self::getTitleInvalidRegex();
2741                 if ( preg_match( $rxTc, $dbkey ) ) {
2742                         return false;
2743                 }
2744
2745                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2746                 # reachable due to the way web browsers deal with 'relative' URLs.
2747                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2748                 if ( strpos( $dbkey, '.' ) !== false &&
2749                          ( $dbkey === '.' || $dbkey === '..' ||
2750                            strpos( $dbkey, './' ) === 0  ||
2751                            strpos( $dbkey, '../' ) === 0 ||
2752                            strpos( $dbkey, '/./' ) !== false ||
2753                            strpos( $dbkey, '/../' ) !== false  ||
2754                            substr( $dbkey, -2 ) == '/.' ||
2755                            substr( $dbkey, -3 ) == '/..' ) )
2756                 {
2757                         return false;
2758                 }
2759
2760                 # Magic tilde sequences? Nu-uh!
2761                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2762                         return false;
2763                 }
2764
2765                 # Limit the size of titles to 255 bytes. This is typically the size of the
2766                 # underlying database field. We make an exception for special pages, which
2767                 # don't need to be stored in the database, and may edge over 255 bytes due
2768                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2769                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2770                   strlen( $dbkey ) > 512 )
2771                 {
2772                         return false;
2773                 }
2774
2775                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2776                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2777                 # other site might be case-sensitive.
2778                 $this->mUserCaseDBKey = $dbkey;
2779                 if ( $this->mInterwiki == '' ) {
2780                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2781                 }
2782
2783                 # Can't make a link to a namespace alone... "empty" local links can only be
2784                 # self-links with a fragment identifier.
2785                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2786                         return false;
2787                 }
2788
2789                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2790                 // IP names are not allowed for accounts, and can only be referring to
2791                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2792                 // there are numerous ways to present the same IP. Having sp:contribs scan
2793                 // them all is silly and having some show the edits and others not is
2794                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2795                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2796                         ? IP::sanitizeIP( $dbkey )
2797                         : $dbkey;
2798
2799                 // Any remaining initial :s are illegal.
2800                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2801                         return false;
2802                 }
2803
2804                 # Fill fields
2805                 $this->mDbkeyform = $dbkey;
2806                 $this->mUrlform = wfUrlencode( $dbkey );
2807
2808                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2809
2810                 return true;
2811         }
2812
2813         /**
2814          * Set the fragment for this title. Removes the first character from the
2815          * specified fragment before setting, so it assumes you're passing it with
2816          * an initial "#".
2817          *
2818          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2819          * Still in active use privately.
2820          *
2821          * @param $fragment String text
2822          */
2823         public function setFragment( $fragment ) {
2824                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2825         }
2826
2827         /**
2828          * Get a Title object associated with the talk page of this article
2829          *
2830          * @return Title the object for the talk page
2831          */
2832         public function getTalkPage() {
2833                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2834         }
2835
2836         /**
2837          * Get a title object associated with the subject page of this
2838          * talk page
2839          *
2840          * @return Title the object for the subject page
2841          */
2842         public function getSubjectPage() {
2843                 // Is this the same title?
2844                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2845                 if ( $this->getNamespace() == $subjectNS ) {
2846                         return $this;
2847                 }
2848                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2849         }
2850
2851         /**
2852          * Get an array of Title objects linking to this Title
2853          * Also stores the IDs in the link cache.
2854          *
2855          * WARNING: do not use this function on arbitrary user-supplied titles!
2856          * On heavily-used templates it will max out the memory.
2857          *
2858          * @param $options Array: may be FOR UPDATE
2859          * @param $table String: table name
2860          * @param $prefix String: fields prefix
2861          * @return Array of Title objects linking here
2862          */
2863         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2864                 $linkCache = LinkCache::singleton();
2865
2866                 if ( count( $options ) > 0 ) {
2867                         $db = wfGetDB( DB_MASTER );
2868                 } else {
2869                         $db = wfGetDB( DB_SLAVE );
2870                 }
2871
2872                 $res = $db->select(
2873                         array( 'page', $table ),
2874                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2875                         array(
2876                                 "{$prefix}_from=page_id",
2877                                 "{$prefix}_namespace" => $this->getNamespace(),
2878                                 "{$prefix}_title"     => $this->getDBkey() ),
2879                         __METHOD__,
2880                         $options
2881                 );
2882
2883                 $retVal = array();
2884                 if ( $db->numRows( $res ) ) {
2885                         foreach ( $res as $row ) {
2886                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2887                                 if ( $titleObj ) {
2888                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2889                                         $retVal[] = $titleObj;
2890                                 }
2891                         }
2892                 }
2893                 return $retVal;
2894         }
2895
2896         /**
2897          * Get an array of Title objects using this Title as a template
2898          * Also stores the IDs in the link cache.
2899          *
2900          * WARNING: do not use this function on arbitrary user-supplied titles!
2901          * On heavily-used templates it will max out the memory.
2902          *
2903          * @param $options Array: may be FOR UPDATE
2904          * @return Array of Title the Title objects linking here
2905          */
2906         public function getTemplateLinksTo( $options = array() ) {
2907                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2908         }
2909
2910         /**
2911          * Get an array of Title objects referring to non-existent articles linked from this page
2912          *
2913          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2914          * @return Array of Title the Title objects
2915          */
2916         public function getBrokenLinksFrom() {
2917                 if ( $this->getArticleId() == 0 ) {
2918                         # All links from article ID 0 are false positives
2919                         return array();
2920                 }
2921
2922                 $dbr = wfGetDB( DB_SLAVE );
2923                 $res = $dbr->select(
2924                         array( 'page', 'pagelinks' ),
2925                         array( 'pl_namespace', 'pl_title' ),
2926                         array(
2927                                 'pl_from' => $this->getArticleId(),
2928                                 'page_namespace IS NULL'
2929                         ),
2930                         __METHOD__, array(),
2931                         array(
2932                                 'page' => array(
2933                                         'LEFT JOIN',
2934                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2935                                 )
2936                         )
2937                 );
2938
2939                 $retVal = array();
2940                 foreach ( $res as $row ) {
2941                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2942                 }
2943                 return $retVal;
2944         }
2945
2946
2947         /**
2948          * Get a list of URLs to purge from the Squid cache when this
2949          * page changes
2950          *
2951          * @return Array of String the URLs
2952          */
2953         public function getSquidURLs() {
2954                 global $wgContLang;
2955
2956                 $urls = array(
2957                         $this->getInternalURL(),
2958                         $this->getInternalURL( 'action=history' )
2959                 );
2960
2961                 // purge variant urls as well
2962                 if ( $wgContLang->hasVariants() ) {
2963                         $variants = $wgContLang->getVariants();
2964                         foreach ( $variants as $vCode ) {
2965                                 $urls[] = $this->getInternalURL( '', $vCode );
2966                         }
2967                 }
2968
2969                 return $urls;
2970         }
2971
2972         /**
2973          * Purge all applicable Squid URLs
2974          */
2975         public function purgeSquid() {
2976                 global $wgUseSquid;
2977                 if ( $wgUseSquid ) {
2978                         $urls = $this->getSquidURLs();
2979                         $u = new SquidUpdate( $urls );
2980                         $u->doUpdate();
2981                 }
2982         }
2983
2984         /**
2985          * Move this page without authentication
2986          *
2987          * @param $nt Title the new page Title
2988          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2989          */
2990         public function moveNoAuth( &$nt ) {
2991                 return $this->moveTo( $nt, false );
2992         }
2993
2994         /**
2995          * Check whether a given move operation would be valid.
2996          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2997          *
2998          * @param $nt Title the new title
2999          * @param $auth Bool indicates whether $wgUser's permissions
3000          *  should be checked
3001          * @param $reason String is the log summary of the move, used for spam checking
3002          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3003          */
3004         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3005                 global $wgUser;
3006
3007                 $errors = array();
3008                 if ( !$nt ) {
3009                         // Normally we'd add this to $errors, but we'll get
3010                         // lots of syntax errors if $nt is not an object
3011                         return array( array( 'badtitletext' ) );
3012                 }
3013                 if ( $this->equals( $nt ) ) {
3014                         $errors[] = array( 'selfmove' );
3015                 }
3016                 if ( !$this->isMovable() ) {
3017                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3018                 }
3019                 if ( $nt->getInterwiki() != '' ) {
3020                         $errors[] = array( 'immobile-target-namespace-iw' );
3021                 }
3022                 if ( !$nt->isMovable() ) {
3023                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3024                 }
3025
3026                 $oldid = $this->getArticleID();
3027                 $newid = $nt->getArticleID();
3028
3029                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3030                         $errors[] = array( 'articleexists' );
3031                 }
3032                 if ( ( $this->getDBkey() == '' ) ||
3033                          ( !$oldid ) ||
3034                          ( $nt->getDBkey() == '' ) ) {
3035                         $errors[] = array( 'badarticleerror' );
3036                 }
3037
3038                 // Image-specific checks
3039                 if ( $this->getNamespace() == NS_FILE ) {
3040                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3041                 }
3042
3043                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3044                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3045                 }
3046
3047                 if ( $auth ) {
3048                         $errors = wfMergeErrorArrays( $errors,
3049                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3050                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3051                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3052                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3053                 }
3054
3055                 $match = EditPage::matchSummarySpamRegex( $reason );
3056                 if ( $match !== false ) {
3057                         // This is kind of lame, won't display nice
3058                         $errors[] = array( 'spamprotectiontext' );
3059                 }
3060
3061                 $err = null;
3062                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3063                         $errors[] = array( 'hookaborted', $err );
3064                 }
3065
3066                 # The move is allowed only if (1) the target doesn't exist, or
3067                 # (2) the target is a redirect to the source, and has no history
3068                 # (so we can undo bad moves right after they're done).
3069
3070                 if ( 0 != $newid ) { # Target exists; check for validity
3071                         if ( !$this->isValidMoveTarget( $nt ) ) {
3072                                 $errors[] = array( 'articleexists' );
3073                         }
3074                 } else {
3075                         $tp = $nt->getTitleProtection();
3076                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3077                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3078                                 $errors[] = array( 'cantmove-titleprotected' );
3079                         }
3080                 }
3081                 if ( empty( $errors ) ) {
3082                         return true;
3083                 }
3084                 return $errors;
3085         }
3086
3087         /**
3088          * Check if the requested move target is a valid file move target
3089          * @param Title $nt Target title
3090          * @return array List of errors
3091          */
3092         protected function validateFileMoveOperation( $nt ) {
3093                 global $wgUser;
3094
3095                 $errors = array();
3096
3097                 if ( $nt->getNamespace() != NS_FILE ) {
3098                         $errors[] = array( 'imagenocrossnamespace' );
3099                 }
3100
3101                 $file = wfLocalFile( $this );
3102                 if ( $file->exists() ) {
3103                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3104                                 $errors[] = array( 'imageinvalidfilename' );
3105                         }
3106                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3107                                 $errors[] = array( 'imagetypemismatch' );
3108                         }
3109                 }
3110
3111                 $destFile = wfLocalFile( $nt );
3112                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3113                         $errors[] = array( 'file-exists-sharedrepo' );
3114                 }
3115
3116                 return $errors;
3117         }
3118
3119         /**
3120          * Move a title to a new location
3121          *
3122          * @param $nt Title the new title
3123          * @param $auth Bool indicates whether $wgUser's permissions
3124          *  should be checked
3125          * @param $reason String the reason for the move
3126          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3127          *  Ignored if the user doesn't have the suppressredirect right.
3128          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3129          */
3130         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3131                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3132                 if ( is_array( $err ) ) {
3133                         return $err;
3134                 }
3135
3136                 // If it is a file, move it first. It is done before all other moving stuff is
3137                 // done because it's hard to revert
3138                 $dbw = wfGetDB( DB_MASTER );
3139                 if ( $this->getNamespace() == NS_FILE ) {
3140                         $file = wfLocalFile( $this );
3141                         if ( $file->exists() ) {
3142                                 $status = $file->move( $nt );
3143                                 if ( !$status->isOk() ) {
3144                                         return $status->getErrorsArray();
3145                                 }
3146                         }
3147                 }
3148
3149                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3150                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3151                 $protected = $this->isProtected();
3152                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3153
3154                 // Do the actual move
3155                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3156                 if ( is_array( $err ) ) {
3157                         # @todo FIXME: What about the File we have already moved?
3158                         $dbw->rollback();
3159                         return $err;
3160                 }
3161
3162                 $redirid = $this->getArticleID();
3163
3164                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3165                 // cl_timestamp, which may disturb time-based lists on some sites.
3166                 $prefixes = $dbw->select(
3167                         'categorylinks',
3168                         array( 'cl_sortkey_prefix', 'cl_to' ),
3169                         array( 'cl_from' => $pageid ),
3170                         __METHOD__
3171                 );
3172                 foreach ( $prefixes as $prefixRow ) {
3173                         $prefix = $prefixRow->cl_sortkey_prefix;
3174                         $catTo = $prefixRow->cl_to;
3175                         $dbw->update( 'categorylinks',
3176                                 array(
3177                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3178                                                 $nt->getCategorySortkey( $prefix ) ),
3179                                         'cl_timestamp=cl_timestamp' ),
3180                                 array(
3181                                         'cl_from' => $pageid,
3182                                         'cl_to' => $catTo ),
3183                                 __METHOD__
3184                         );
3185                 }
3186
3187                 if ( $protected ) {
3188                         # Protect the redirect title as the title used to be...
3189                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3190                                 array(
3191                                         'pr_page'    => $redirid,
3192                                         'pr_type'    => 'pr_type',
3193                                         'pr_level'   => 'pr_level',
3194                                         'pr_cascade' => 'pr_cascade',
3195                                         'pr_user'    => 'pr_user',
3196                                         'pr_expiry'  => 'pr_expiry'
3197                                 ),
3198                                 array( 'pr_page' => $pageid ),
3199                                 __METHOD__,
3200                                 array( 'IGNORE' )
3201                         );
3202                         # Update the protection log
3203                         $log = new LogPage( 'protect' );
3204                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3205                         if ( $reason ) {
3206                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3207                         }
3208                         // @todo FIXME: $params?
3209                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3210                 }
3211
3212                 # Update watchlists
3213                 $oldnamespace = $this->getNamespace() & ~1;
3214                 $newnamespace = $nt->getNamespace() & ~1;
3215                 $oldtitle = $this->getDBkey();
3216                 $newtitle = $nt->getDBkey();
3217
3218                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3219                         WatchedItem::duplicateEntries( $this, $nt );
3220                 }
3221
3222                 # Update search engine
3223                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3224                 $u->doUpdate();
3225                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3226                 $u->doUpdate();
3227
3228                 $dbw->commit();
3229
3230                 # Update site_stats
3231                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3232                         # No longer a content page
3233                         # Not viewed, edited, removing
3234                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3235                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3236                         # Now a content page
3237                         # Not viewed, edited, adding
3238                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3239                 } elseif ( $pageCountChange ) {
3240                         # Redirect added
3241                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3242                 } else {
3243                         # Nothing special
3244                         $u = false;
3245                 }
3246                 if ( $u ) {
3247                         $u->doUpdate();
3248                 }
3249
3250                 # Update message cache for interface messages
3251                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3252                         # @bug 17860: old article can be deleted, if this the case,
3253                         # delete it from message cache
3254                         if ( $this->getArticleID() === 0 ) {
3255                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3256                         } else {
3257                                 $oldarticle = new Article( $this );
3258                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3259                         }
3260                 }
3261                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3262                         $newarticle = new Article( $nt );
3263                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3264                 }
3265
3266                 global $wgUser;
3267                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3268                 return true;
3269         }
3270
3271         /**
3272          * Move page to a title which is either a redirect to the
3273          * source page or nonexistent
3274          *
3275          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3276          * @param $reason String The reason for the move
3277          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3278          *   if the user doesn't have the suppressredirect right
3279          */
3280         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3281                 global $wgUser, $wgContLang;
3282
3283                 $moveOverRedirect = $nt->exists();
3284
3285                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3286                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3287
3288                 if ( $reason ) {
3289                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3290                 }
3291                 # Truncate for whole multibyte characters.
3292                 $comment = $wgContLang->truncate( $comment, 255 );
3293
3294                 $oldid = $this->getArticleID();
3295                 $latest = $this->getLatestRevID();
3296
3297                 $dbw = wfGetDB( DB_MASTER );
3298
3299                 if ( $moveOverRedirect ) {
3300                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3301
3302                         $newid = $nt->getArticleID();
3303                         $newns = $nt->getNamespace();
3304                         $newdbk = $nt->getDBkey();
3305
3306                         # Delete the old redirect. We don't save it to history since
3307                         # by definition if we've got here it's rather uninteresting.
3308                         # We have to remove it so that the next step doesn't trigger
3309                         # a conflict on the unique namespace+title index...
3310                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3311                         if ( !$dbw->cascadingDeletes() ) {
3312                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3313                                 global $wgUseTrackbacks;
3314                                 if ( $wgUseTrackbacks ) {
3315                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3316                                 }
3317                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3318                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3319                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3320                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3321                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3322                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3323                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3324                         }
3325                         // If the target page was recently created, it may have an entry in recentchanges still
3326                         $dbw->delete( 'recentchanges',
3327                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3328                                 __METHOD__
3329                         );
3330                 }
3331
3332                 # Save a null revision in the page's history notifying of the move
3333                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3334                 if ( !is_object( $nullRevision ) ) {
3335                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3336                 }
3337                 $nullRevId = $nullRevision->insertOn( $dbw );
3338
3339                 $now = wfTimestampNow();
3340                 # Change the name of the target page:
3341                 $dbw->update( 'page',
3342                         /* SET */ array(
3343                                 'page_touched'   => $dbw->timestamp( $now ),
3344                                 'page_namespace' => $nt->getNamespace(),
3345                                 'page_title'     => $nt->getDBkey(),
3346                                 'page_latest'    => $nullRevId,
3347                         ),
3348                         /* WHERE */ array( 'page_id' => $oldid ),
3349                         __METHOD__
3350                 );
3351                 $nt->resetArticleID( $oldid );
3352
3353                 $article = new Article( $nt );
3354                 wfRunHooks( 'NewRevisionFromEditComplete',
3355                         array( $article, $nullRevision, $latest, $wgUser ) );
3356                 $article->setCachedLastEditTime( $now );
3357
3358                 # Recreate the redirect, this time in the other direction.
3359                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3360                         $mwRedir = MagicWord::get( 'redirect' );
3361                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3362                         $redirectArticle = new Article( $this );
3363                         $newid = $redirectArticle->insertOn( $dbw );
3364                         if ( $newid ) { // sanity
3365                                 $redirectRevision = new Revision( array(
3366                                         'page'    => $newid,
3367                                         'comment' => $comment,
3368                                         'text'    => $redirectText ) );
3369                                 $redirectRevision->insertOn( $dbw );
3370                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3371
3372                                 wfRunHooks( 'NewRevisionFromEditComplete',
3373                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3374
3375                                 # Now, we record the link from the redirect to the new title.
3376                                 # It should have no other outgoing links...
3377                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3378                                 $dbw->insert( 'pagelinks',
3379                                         array(
3380                                                 'pl_from'      => $newid,
3381                                                 'pl_namespace' => $nt->getNamespace(),
3382                                                 'pl_title'     => $nt->getDBkey() ),
3383                                         __METHOD__ );
3384                         }
3385                         $redirectSuppressed = false;
3386                 } else {
3387                         $this->resetArticleID( 0 );
3388                         $redirectSuppressed = true;
3389                 }
3390
3391                 # Log the move
3392                 $log = new LogPage( 'move' );
3393                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3394                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3395
3396                 # Purge caches for old and new titles
3397                 if ( $moveOverRedirect ) {
3398                         # A simple purge is enough when moving over a redirect
3399                         $nt->purgeSquid();
3400                 } else {
3401                         # Purge caches as per article creation, including any pages that link to this title
3402                         Article::onArticleCreate( $nt );
3403                 }
3404                 $this->purgeSquid();
3405         }
3406
3407         /**
3408          * Move this page's subpages to be subpages of $nt
3409          *
3410          * @param $nt Title Move target
3411          * @param $auth bool Whether $wgUser's permissions should be checked
3412          * @param $reason string The reason for the move
3413          * @param $createRedirect bool Whether to create redirects from the old subpages to
3414          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3415          * @return mixed array with old page titles as keys, and strings (new page titles) or
3416          *     arrays (errors) as values, or an error array with numeric indices if no pages
3417          *     were moved
3418          */
3419         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3420                 global $wgMaximumMovedPages;
3421                 // Check permissions
3422                 if ( !$this->userCan( 'move-subpages' ) ) {
3423                         return array( 'cant-move-subpages' );
3424                 }
3425                 // Do the source and target namespaces support subpages?
3426                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3427                         return array( 'namespace-nosubpages',
3428                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3429                 }
3430                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3431                         return array( 'namespace-nosubpages',
3432                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3433                 }
3434
3435                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3436                 $retval = array();
3437                 $count = 0;
3438                 foreach ( $subpages as $oldSubpage ) {
3439                         $count++;
3440                         if ( $count > $wgMaximumMovedPages ) {
3441                                 $retval[$oldSubpage->getPrefixedTitle()] =
3442                                                 array( 'movepage-max-pages',
3443                                                         $wgMaximumMovedPages );
3444                                 break;
3445                         }
3446
3447                         // We don't know whether this function was called before
3448                         // or after moving the root page, so check both
3449                         // $this and $nt
3450                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3451                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3452                         {
3453                                 // When moving a page to a subpage of itself,
3454                                 // don't move it twice
3455                                 continue;
3456                         }
3457                         $newPageName = preg_replace(
3458                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3459                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3460                                         $oldSubpage->getDBkey() );
3461                         if ( $oldSubpage->isTalkPage() ) {
3462                                 $newNs = $nt->getTalkPage()->getNamespace();
3463                         } else {
3464                                 $newNs = $nt->getSubjectPage()->getNamespace();
3465                         }
3466                         # Bug 14385: we need makeTitleSafe because the new page names may
3467                         # be longer than 255 characters.
3468                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3469
3470                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3471                         if ( $success === true ) {
3472                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3473                         } else {
3474                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3475                         }
3476                 }
3477                 return $retval;
3478         }
3479
3480         /**
3481          * Checks if this page is just a one-rev redirect.
3482          * Adds lock, so don't use just for light purposes.
3483          *
3484          * @return Bool
3485          */
3486         public function isSingleRevRedirect() {
3487                 $dbw = wfGetDB( DB_MASTER );
3488                 # Is it a redirect?
3489                 $row = $dbw->selectRow( 'page',
3490                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3491                         $this->pageCond(),
3492                         __METHOD__,
3493                         array( 'FOR UPDATE' )
3494                 );
3495                 # Cache some fields we may want
3496                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3497                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3498                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3499                 if ( !$this->mRedirect ) {
3500                         return false;
3501                 }
3502                 # Does the article have a history?
3503                 $row = $dbw->selectField( array( 'page', 'revision' ),
3504                         'rev_id',
3505                         array( 'page_namespace' => $this->getNamespace(),
3506                                 'page_title' => $this->getDBkey(),
3507                                 'page_id=rev_page',
3508                                 'page_latest != rev_id'
3509                         ),
3510                         __METHOD__,
3511                         array( 'FOR UPDATE' )
3512                 );
3513                 # Return true if there was no history
3514                 return ( $row === false );
3515         }
3516
3517         /**
3518          * Checks if $this can be moved to a given Title
3519          * - Selects for update, so don't call it unless you mean business
3520          *
3521          * @param $nt Title the new title to check
3522          * @return Bool
3523          */
3524         public function isValidMoveTarget( $nt ) {
3525                 # Is it an existing file?
3526                 if ( $nt->getNamespace() == NS_FILE ) {
3527                         $file = wfLocalFile( $nt );
3528                         if ( $file->exists() ) {
3529                                 wfDebug( __METHOD__ . ": file exists\n" );
3530                                 return false;
3531                         }
3532                 }
3533                 # Is it a redirect with no history?
3534                 if ( !$nt->isSingleRevRedirect() ) {
3535                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3536                         return false;
3537                 }
3538                 # Get the article text
3539                 $rev = Revision::newFromTitle( $nt );
3540                 $text = $rev->getText();
3541                 # Does the redirect point to the source?
3542                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3543                 $m = array();
3544                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3545                         $redirTitle = Title::newFromText( $m[1] );
3546                         if ( !is_object( $redirTitle ) ||
3547                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3548                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3549                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3550                                 return false;
3551                         }
3552                 } else {
3553                         # Fail safe
3554                         wfDebug( __METHOD__ . ": failsafe\n" );
3555                         return false;
3556                 }
3557                 return true;
3558         }
3559
3560         /**
3561          * Can this title be added to a user's watchlist?
3562          *
3563          * @return Bool TRUE or FALSE
3564          */
3565         public function isWatchable() {
3566                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3567         }
3568
3569         /**
3570          * Get categories to which this Title belongs and return an array of
3571          * categories' names.
3572          *
3573          * @return Array of parents in the form:
3574          *        $parent => $currentarticle
3575          */
3576         public function getParentCategories() {
3577                 global $wgContLang;
3578
3579                 $data = array();
3580
3581                 $titleKey = $this->getArticleId();
3582
3583                 if ( $titleKey === 0 ) {
3584                         return $data;
3585                 }
3586
3587                 $dbr = wfGetDB( DB_SLAVE );
3588
3589                 $res = $dbr->select( 'categorylinks', '*',
3590                         array(
3591                                 'cl_from' => $titleKey,
3592                         ),
3593                         __METHOD__,
3594                         array()
3595                 );
3596
3597                 if ( $dbr->numRows( $res ) > 0 ) {
3598                         foreach ( $res as $row ) {
3599                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3600                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3601                         }
3602                 }
3603                 return $data;
3604         }
3605
3606         /**
3607          * Get a tree of parent categories
3608          *
3609          * @param $children Array with the children in the keys, to check for circular refs
3610          * @return Array Tree of parent categories
3611          */
3612         public function getParentCategoryTree( $children = array() ) {
3613                 $stack = array();
3614                 $parents = $this->getParentCategories();
3615
3616                 if ( $parents ) {
3617                         foreach ( $parents as $parent => $current ) {
3618                                 if ( array_key_exists( $parent, $children ) ) {
3619                                         # Circular reference
3620                                         $stack[$parent] = array();
3621                                 } else {
3622                                         $nt = Title::newFromText( $parent );
3623                                         if ( $nt ) {
3624                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3625                                         }
3626                                 }
3627                         }
3628                 }
3629
3630                 return $stack;
3631         }
3632
3633         /**
3634          * Get an associative array for selecting this title from
3635          * the "page" table
3636          *
3637          * @return Array suitable for the $where parameter of DB::select()
3638          */
3639         public function pageCond() {
3640                 if ( $this->mArticleID > 0 ) {
3641                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3642                         return array( 'page_id' => $this->mArticleID );
3643                 } else {
3644                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3645                 }
3646         }
3647
3648         /**
3649          * Get the revision ID of the previous revision
3650          *
3651          * @param $revId Int Revision ID. Get the revision that was before this one.
3652          * @param $flags Int Title::GAID_FOR_UPDATE
3653          * @return Int|Bool Old revision ID, or FALSE if none exists
3654          */
3655         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3656                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3657                 return $db->selectField( 'revision', 'rev_id',
3658                         array(
3659                                 'rev_page' => $this->getArticleId( $flags ),
3660                                 'rev_id < ' . intval( $revId )
3661                         ),
3662                         __METHOD__,
3663                         array( 'ORDER BY' => 'rev_id DESC' )
3664                 );
3665         }
3666
3667         /**
3668          * Get the revision ID of the next revision
3669          *
3670          * @param $revId Int Revision ID. Get the revision that was after this one.
3671          * @param $flags Int Title::GAID_FOR_UPDATE
3672          * @return Int|Bool Next revision ID, or FALSE if none exists
3673          */
3674         public function getNextRevisionID( $revId, $flags = 0 ) {
3675                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3676                 return $db->selectField( 'revision', 'rev_id',
3677                         array(
3678                                 'rev_page' => $this->getArticleId( $flags ),
3679                                 'rev_id > ' . intval( $revId )
3680                         ),
3681                         __METHOD__,
3682                         array( 'ORDER BY' => 'rev_id' )
3683                 );
3684         }
3685
3686         /**
3687          * Get the first revision of the page
3688          *
3689          * @param $flags Int Title::GAID_FOR_UPDATE
3690          * @return Revision|Null if page doesn't exist
3691          */
3692         public function getFirstRevision( $flags = 0 ) {
3693                 $pageId = $this->getArticleId( $flags );
3694                 if ( $pageId ) {
3695                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3696                         $row = $db->selectRow( 'revision', '*',
3697                                 array( 'rev_page' => $pageId ),
3698                                 __METHOD__,
3699                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3700                         );
3701                         if ( $row ) {
3702                                 return new Revision( $row );
3703                         }
3704                 }
3705                 return null;
3706         }
3707
3708         /**
3709          * Get the oldest revision timestamp of this page
3710          *
3711          * @param $flags Int Title::GAID_FOR_UPDATE
3712          * @return String: MW timestamp
3713          */
3714         public function getEarliestRevTime( $flags = 0 ) {
3715                 $rev = $this->getFirstRevision( $flags );
3716                 return $rev ? $rev->getTimestamp() : null;
3717         }
3718
3719         /**
3720          * Check if this is a new page
3721          *
3722          * @return bool
3723          */
3724         public function isNewPage() {
3725                 $dbr = wfGetDB( DB_SLAVE );
3726                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3727         }
3728
3729         /**
3730          * Get the number of revisions between the given revision.
3731          * Used for diffs and other things that really need it.
3732          *
3733          * @param $old int|Revision Old revision or rev ID (first before range)
3734          * @param $new int|Revision New revision or rev ID (first after range)
3735          * @return Int Number of revisions between these revisions.
3736          */
3737         public function countRevisionsBetween( $old, $new ) {
3738                 if ( !( $old instanceof Revision ) ) {
3739                         $old = Revision::newFromTitle( $this, (int)$old );
3740                 }
3741                 if ( !( $new instanceof Revision ) ) {
3742                         $new = Revision::newFromTitle( $this, (int)$new );
3743                 }
3744                 if ( !$old || !$new ) {
3745                         return 0; // nothing to compare
3746                 }
3747                 $dbr = wfGetDB( DB_SLAVE );
3748                 return (int)$dbr->selectField( 'revision', 'count(*)',
3749                         array(
3750                                 'rev_page' => $this->getArticleId(),
3751                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3752                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3753                         ),
3754                         __METHOD__
3755                 );
3756         }
3757
3758         /**
3759          * Get the number of authors between the given revision IDs.
3760          * Used for diffs and other things that really need it.
3761          *
3762          * @param $old int|Revision Old revision or rev ID (first before range)
3763          * @param $new int|Revision New revision or rev ID (first after range)
3764          * @param $limit Int Maximum number of authors
3765          * @return Int Number of revision authors between these revisions.
3766          */
3767         public function countAuthorsBetween( $old, $new, $limit ) {
3768                 if ( !( $old instanceof Revision ) ) {
3769                         $old = Revision::newFromTitle( $this, (int)$old );
3770                 }
3771                 if ( !( $new instanceof Revision ) ) {
3772                         $new = Revision::newFromTitle( $this, (int)$new );
3773                 }
3774                 if ( !$old || !$new ) {
3775                         return 0; // nothing to compare
3776                 }
3777                 $dbr = wfGetDB( DB_SLAVE );
3778                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3779                         array(
3780                                 'rev_page' => $this->getArticleID(),
3781                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3782                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3783                         ), __METHOD__,
3784                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3785                 );
3786                 return (int)$dbr->numRows( $res );
3787         }
3788
3789         /**
3790          * Compare with another title.
3791          *
3792          * @param $title Title
3793          * @return Bool
3794          */
3795         public function equals( Title $title ) {
3796                 // Note: === is necessary for proper matching of number-like titles.
3797                 return $this->getInterwiki() === $title->getInterwiki()
3798                         && $this->getNamespace() == $title->getNamespace()
3799                         && $this->getDBkey() === $title->getDBkey();
3800         }
3801
3802         /**
3803          * Callback for usort() to do title sorts by (namespace, title)
3804          *
3805          * @param $a Title
3806          * @param $b Title
3807          *
3808          * @return Integer: result of string comparison, or namespace comparison
3809          */
3810         public static function compare( $a, $b ) {
3811                 if ( $a->getNamespace() == $b->getNamespace() ) {
3812                         return strcmp( $a->getText(), $b->getText() );
3813                 } else {
3814                         return $a->getNamespace() - $b->getNamespace();
3815                 }
3816         }
3817
3818         /**
3819          * Return a string representation of this title
3820          *
3821          * @return String representation of this title
3822          */
3823         public function __toString() {
3824                 return $this->getPrefixedText();
3825         }
3826
3827         /**
3828          * Check if page exists.  For historical reasons, this function simply
3829          * checks for the existence of the title in the page table, and will
3830          * thus return false for interwiki links, special pages and the like.
3831          * If you want to know if a title can be meaningfully viewed, you should
3832          * probably call the isKnown() method instead.
3833          *
3834          * @return Bool
3835          */
3836         public function exists() {
3837                 return $this->getArticleId() != 0;
3838         }
3839
3840         /**
3841          * Should links to this title be shown as potentially viewable (i.e. as
3842          * "bluelinks"), even if there's no record by this title in the page
3843          * table?
3844          *
3845          * This function is semi-deprecated for public use, as well as somewhat
3846          * misleadingly named.  You probably just want to call isKnown(), which
3847          * calls this function internally.
3848          *
3849          * (ISSUE: Most of these checks are cheap, but the file existence check
3850          * can potentially be quite expensive.  Including it here fixes a lot of
3851          * existing code, but we might want to add an optional parameter to skip
3852          * it and any other expensive checks.)
3853          *
3854          * @return Bool
3855          */
3856         public function isAlwaysKnown() {
3857                 if ( $this->mInterwiki != '' ) {
3858                         return true;  // any interwiki link might be viewable, for all we know
3859                 }
3860                 switch( $this->mNamespace ) {
3861                         case NS_MEDIA:
3862                         case NS_FILE:
3863                                 // file exists, possibly in a foreign repo
3864                                 return (bool)wfFindFile( $this );
3865                         case NS_SPECIAL:
3866                                 // valid special page
3867                                 return SpecialPageFactory::exists( $this->getDBkey() );
3868                         case NS_MAIN:
3869                                 // selflink, possibly with fragment
3870                                 return $this->mDbkeyform == '';
3871                         case NS_MEDIAWIKI:
3872                                 // known system message
3873                                 return $this->getDefaultMessageText() !== false;
3874                         default:
3875                                 return false;
3876                 }
3877         }
3878
3879         /**
3880          * Does this title refer to a page that can (or might) be meaningfully
3881          * viewed?  In particular, this function may be used to determine if
3882          * links to the title should be rendered as "bluelinks" (as opposed to
3883          * "redlinks" to non-existent pages).
3884          *
3885          * @return Bool
3886          */
3887         public function isKnown() {
3888                 return $this->isAlwaysKnown() || $this->exists();
3889         }
3890
3891         /**
3892          * Does this page have source text?
3893          *
3894          * @return Boolean
3895          */
3896         public function hasSourceText() {
3897                 if ( $this->exists() ) {
3898                         return true;
3899                 }
3900
3901                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3902                         // If the page doesn't exist but is a known system message, default
3903                         // message content will be displayed, same for language subpages
3904                         return $this->getDefaultMessageText() !== false;
3905                 }
3906
3907                 return false;
3908         }
3909
3910         /**
3911          * Get the default message text or false if the message doesn't exist
3912          *
3913          * @return String or false
3914          */
3915         public function getDefaultMessageText() {
3916                 global $wgContLang;
3917
3918                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3919                         return false;
3920                 }
3921
3922                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3923                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3924
3925                 if ( $message->exists() ) {
3926                         return $message->plain();
3927                 } else {
3928                         return false;
3929                 }
3930         }
3931
3932         /**
3933          * Is this in a namespace that allows actual pages?
3934          *
3935          * @return Bool
3936          * @internal note -- uses hardcoded namespace index instead of constants
3937          */
3938         public function canExist() {
3939                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3940         }
3941
3942         /**
3943          * Update page_touched timestamps and send squid purge messages for
3944          * pages linking to this title. May be sent to the job queue depending
3945          * on the number of links. Typically called on create and delete.
3946          */
3947         public function touchLinks() {
3948                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3949                 $u->doUpdate();
3950
3951                 if ( $this->getNamespace() == NS_CATEGORY ) {
3952                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3953                         $u->doUpdate();
3954                 }
3955         }
3956
3957         /**
3958          * Get the last touched timestamp
3959          *
3960          * @param $db DatabaseBase: optional db
3961          * @return String last-touched timestamp
3962          */
3963         public function getTouched( $db = null ) {
3964                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3965                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3966                 return $touched;
3967         }
3968
3969         /**
3970          * Get the timestamp when this page was updated since the user last saw it.
3971          *
3972          * @param $user User
3973          * @return String|Null
3974          */
3975         public function getNotificationTimestamp( $user = null ) {
3976                 global $wgUser, $wgShowUpdatedMarker;
3977                 // Assume current user if none given
3978                 if ( !$user ) {
3979                         $user = $wgUser;
3980                 }
3981                 // Check cache first
3982                 $uid = $user->getId();
3983                 // avoid isset here, as it'll return false for null entries
3984                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
3985                         return $this->mNotificationTimestamp[$uid];
3986                 }
3987                 if ( !$uid || !$wgShowUpdatedMarker ) {
3988                         return $this->mNotificationTimestamp[$uid] = false;
3989                 }
3990                 // Don't cache too much!
3991                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3992                         $this->mNotificationTimestamp = array();
3993                 }
3994                 $dbr = wfGetDB( DB_SLAVE );
3995                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3996                         'wl_notificationtimestamp',
3997                         array( 'wl_namespace' => $this->getNamespace(),
3998                                 'wl_title' => $this->getDBkey(),
3999                                 'wl_user' => $user->getId()
4000                         ),
4001                         __METHOD__
4002                 );
4003                 return $this->mNotificationTimestamp[$uid];
4004         }
4005
4006         /**
4007          * Get the trackback URL for this page
4008          *
4009          * @return String Trackback URL
4010          */
4011         public function trackbackURL() {
4012                 global $wgScriptPath, $wgServer, $wgScriptExtension;
4013
4014                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
4015                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
4016         }
4017
4018         /**
4019          * Get the trackback RDF for this page
4020          *
4021          * @return String Trackback RDF
4022          */
4023         public function trackbackRDF() {
4024                 $url = htmlspecialchars( $this->getFullURL() );
4025                 $title = htmlspecialchars( $this->getText() );
4026                 $tburl = $this->trackbackURL();
4027
4028                 // Autodiscovery RDF is placed in comments so HTML validator
4029                 // won't barf. This is a rather icky workaround, but seems
4030                 // frequently used by this kind of RDF thingy.
4031                 //
4032                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4033                 return "<!--
4034 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4035                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4036                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4037 <rdf:Description
4038    rdf:about=\"$url\"
4039    dc:identifier=\"$url\"
4040    dc:title=\"$title\"
4041    trackback:ping=\"$tburl\" />
4042 </rdf:RDF>
4043 -->";
4044         }
4045
4046         /**
4047          * Generate strings used for xml 'id' names in monobook tabs
4048          *
4049          * @param $prepend string defaults to 'nstab-'
4050          * @return String XML 'id' name
4051          */
4052         public function getNamespaceKey( $prepend = 'nstab-' ) {
4053                 global $wgContLang;
4054                 // Gets the subject namespace if this title
4055                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4056                 // Checks if cononical namespace name exists for namespace
4057                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4058                         // Uses canonical namespace name
4059                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4060                 } else {
4061                         // Uses text of namespace
4062                         $namespaceKey = $this->getSubjectNsText();
4063                 }
4064                 // Makes namespace key lowercase
4065                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4066                 // Uses main
4067                 if ( $namespaceKey == '' ) {
4068                         $namespaceKey = 'main';
4069                 }
4070                 // Changes file to image for backwards compatibility
4071                 if ( $namespaceKey == 'file' ) {
4072                         $namespaceKey = 'image';
4073                 }
4074                 return $prepend . $namespaceKey;
4075         }
4076
4077         /**
4078          * Returns true if this is a special page.
4079          *
4080          * @return boolean
4081          */
4082         public function isSpecialPage() {
4083                 return $this->getNamespace() == NS_SPECIAL;
4084         }
4085
4086         /**
4087          * Returns true if this title resolves to the named special page
4088          *
4089          * @param $name String The special page name
4090          * @return boolean
4091          */
4092         public function isSpecial( $name ) {
4093                 if ( $this->getNamespace() == NS_SPECIAL ) {
4094                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4095                         if ( $name == $thisName ) {
4096                                 return true;
4097                         }
4098                 }
4099                 return false;
4100         }
4101
4102         /**
4103          * If the Title refers to a special page alias which is not the local default, resolve
4104          * the alias, and localise the name as necessary.  Otherwise, return $this
4105          *
4106          * @return Title
4107          */
4108         public function fixSpecialName() {
4109                 if ( $this->getNamespace() == NS_SPECIAL ) {
4110                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4111                         if ( $canonicalName ) {
4112                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4113                                 if ( $localName != $this->mDbkeyform ) {
4114                                         return Title::makeTitle( NS_SPECIAL, $localName );
4115                                 }
4116                         }
4117                 }
4118                 return $this;
4119         }
4120
4121         /**
4122          * Is this Title in a namespace which contains content?
4123          * In other words, is this a content page, for the purposes of calculating
4124          * statistics, etc?
4125          *
4126          * @return Boolean
4127          */
4128         public function isContentPage() {
4129                 return MWNamespace::isContent( $this->getNamespace() );
4130         }
4131
4132         /**
4133          * Get all extant redirects to this Title
4134          *
4135          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4136          * @return Array of Title redirects to this title
4137          */
4138         public function getRedirectsHere( $ns = null ) {
4139                 $redirs = array();
4140
4141                 $dbr = wfGetDB( DB_SLAVE );
4142                 $where = array(
4143                         'rd_namespace' => $this->getNamespace(),
4144                         'rd_title' => $this->getDBkey(),
4145                         'rd_from = page_id'
4146                 );
4147                 if ( !is_null( $ns ) ) {
4148                         $where['page_namespace'] = $ns;
4149                 }
4150
4151                 $res = $dbr->select(
4152                         array( 'redirect', 'page' ),
4153                         array( 'page_namespace', 'page_title' ),
4154                         $where,
4155                         __METHOD__
4156                 );
4157
4158                 foreach ( $res as $row ) {
4159                         $redirs[] = self::newFromRow( $row );
4160                 }
4161                 return $redirs;
4162         }
4163
4164         /**
4165          * Check if this Title is a valid redirect target
4166          *
4167          * @return Bool
4168          */
4169         public function isValidRedirectTarget() {
4170                 global $wgInvalidRedirectTargets;
4171
4172                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4173                 if ( $this->isSpecial( 'Userlogout' ) ) {
4174                         return false;
4175                 }
4176
4177                 foreach ( $wgInvalidRedirectTargets as $target ) {
4178                         if ( $this->isSpecial( $target ) ) {
4179                                 return false;
4180                         }
4181                 }
4182
4183                 return true;
4184         }
4185
4186         /**
4187          * Get a backlink cache object
4188          *
4189          * @return object BacklinkCache
4190          */
4191         function getBacklinkCache() {
4192                 if ( is_null( $this->mBacklinkCache ) ) {
4193                         $this->mBacklinkCache = new BacklinkCache( $this );
4194                 }
4195                 return $this->mBacklinkCache;
4196         }
4197
4198         /**
4199          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4200          *
4201          * @return Boolean
4202          */
4203         public function canUseNoindex() {
4204                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4205
4206                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4207                         ? $wgContentNamespaces
4208                         : $wgExemptFromUserRobotsControl;
4209
4210                 return !in_array( $this->mNamespace, $bannedNamespaces );
4211
4212         }
4213
4214         /**
4215          * Returns restriction types for the current Title
4216          *
4217          * @return array applicable restriction types
4218          */
4219         public function getRestrictionTypes() {
4220                 if ( $this->getNamespace() == NS_SPECIAL ) {
4221                         return array();
4222                 }
4223
4224                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4225
4226                 if ( $this->getNamespace() != NS_FILE ) {
4227                         # Remove the upload restriction for non-file titles
4228                         $types = array_diff( $types, array( 'upload' ) );
4229                 }
4230
4231                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4232
4233                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4234                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4235
4236                 return $types;
4237         }
4238         /**
4239          * Get a filtered list of all restriction types supported by this wiki.
4240          * @param bool $exists True to get all restriction types that apply to
4241          * titles that do exist, False for all restriction types that apply to
4242          * titles that do not exist
4243          * @return array
4244          */
4245         public static function getFilteredRestrictionTypes( $exists = true ) {
4246                 global $wgRestrictionTypes;
4247                 $types = $wgRestrictionTypes;
4248                 if ( $exists ) {
4249                         # Remove the create restriction for existing titles
4250                         $types = array_diff( $types, array( 'create' ) );
4251                 } else {
4252                         # Only the create and upload restrictions apply to non-existing titles
4253                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4254                 }
4255                 return $types;
4256         }
4257
4258         /**
4259          * Returns the raw sort key to be used for categories, with the specified
4260          * prefix.  This will be fed to Collation::getSortKey() to get a
4261          * binary sortkey that can be used for actual sorting.
4262          *
4263          * @param $prefix string The prefix to be used, specified using
4264          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4265          *   prefix.
4266          * @return string
4267          */
4268         public function getCategorySortkey( $prefix = '' ) {
4269                 $unprefixed = $this->getText();
4270
4271                 // Anything that uses this hook should only depend
4272                 // on the Title object passed in, and should probably
4273                 // tell the users to run updateCollations.php --force
4274                 // in order to re-sort existing category relations.
4275                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4276                 if ( $prefix !== '' ) {
4277                         # Separate with a line feed, so the unprefixed part is only used as
4278                         # a tiebreaker when two pages have the exact same prefix.
4279                         # In UCA, tab is the only character that can sort above LF
4280                         # so we strip both of them from the original prefix.
4281                         $prefix = strtr( $prefix, "\n\t", '  ' );
4282                         return "$prefix\n$unprefixed";
4283                 }
4284                 return $unprefixed;
4285         }
4286
4287         /**
4288          * Get the language in which the content of this page is written.
4289          * Defaults to $wgContLang, but in certain cases it can be e.g.
4290          * $wgLang (such as special pages, which are in the user language).
4291          *
4292          * @since 1.18
4293          * @return object Language
4294          */
4295         public function getPageLanguage() {
4296                 global $wgLang;
4297                 if ( $this->getNamespace() == NS_SPECIAL ) {
4298                         // special pages are in the user language
4299                         return $wgLang;
4300                 } elseif ( $this->isRedirect() ) {
4301                         // the arrow on a redirect page is aligned according to the user language
4302                         return $wgLang;
4303                 } elseif ( $this->isCssOrJsPage() ) {
4304                         // css/js should always be LTR and is, in fact, English
4305                         return wfGetLangObj( 'en' );
4306                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4307                         // Parse mediawiki messages with correct target language
4308                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4309                         return wfGetLangObj( $lang );
4310                 }
4311                 global $wgContLang;
4312                 // If nothing special, it should be in the wiki content language
4313                 $pageLang = $wgContLang;
4314                 // Hook at the end because we don't want to override the above stuff
4315                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4316                 return wfGetLangObj( $pageLang );
4317         }
4318 }
4319
4320 /**
4321  * A BadTitle is generated in MediaWiki::parseTitle() if the title is invalid; the
4322  * software uses this to display an error page.  Internally it's basically a Title
4323  * for an empty special page
4324  */
4325 class BadTitle extends Title {
4326         public function __construct(){
4327                 $this->mTextform = '';
4328                 $this->mUrlform = '';
4329                 $this->mDbkeyform = '';
4330                 $this->mNamespace = NS_SPECIAL; // Stops talk page link, etc, being shown
4331         }
4332
4333         public function exists(){
4334                 return false;
4335         }
4336
4337         public function getPrefixedText(){
4338                 return '';
4339         }
4340
4341         public function getText(){
4342                 return '';
4343         }
4344
4345         public function getPrefixedURL(){
4346                 return '';
4347         }
4348
4349         public function getPrefixedDBKey(){
4350                 return '';
4351         }
4352 }