includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Represents a title within MediaWiki.
  25  * Optionally may contain an interwiki designation or namespace.
  26  * @note This class can fetch various kinds of data from the database;
  27  *       however, it does so inefficiently.
  28  *
  29  * @internal documentation reviewed 15 Mar 2010
  30  */
  31 class Title {
  32         /** @name Static cache variables */
  33         // @{
  34         static private $titleCache = array();
  35         // @}
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  58         var $mUrlform = '';               // /< URL-encoded form of the main part
  59         var $mDbkeyform = '';             // /< Main part with underscores
  60         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  61         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  62         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  63         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  64         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  65         var $mLatestID = false;           // /< ID of most recent revision
  66         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  67         var $mOldRestrictions = false;
  68         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  69         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  70         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  71         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  72         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  73         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  74         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  75         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  76         # Don't change the following default, NS_MAIN is hardcoded in several
  77         # places.  See bug 696.
  78         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  79                                                                           # Zero except in {{transclusion}} tags
  80         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  81         var $mLength = -1;                // /< The page length, 0 for special pages
  82         var $mRedirect = null;            // /< Is the article at this title a redirect?
  83         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  84         var $mBacklinkCache = null;       // /< Cache of links to this title
  85         // @}
  86
  87
  88         /**
  89          * Constructor
  90          */
  91         /*protected*/ function __construct() { }
  92
  93         /**
  94          * Create a new Title from a prefixed DB key
  95          *
  96          * @param $key String the database key, which has underscores
  97          *      instead of spaces, possibly including namespace and
  98          *      interwiki prefixes
  99          * @return Title, or NULL on an error
 100          */
 101         public static function newFromDBkey( $key ) {
 102                 $t = new Title();
 103                 $t->mDbkeyform = $key;
 104                 if ( $t->secureAndSplit() ) {
 105                         return $t;
 106                 } else {
 107                         return null;
 108                 }
 109         }
 110
 111         /**
 112          * Create a new Title from text, such as what one would find in a link. De-
 113          * codes any HTML entities in the text.
 114          *
 115          * @param $text String the link text; spaces, prefixes, and an
 116          *   initial ':' indicating the main namespace are accepted.
 117          * @param $defaultNamespace Int the namespace to use if none is speci-
 118          *   fied by a prefix.  If you want to force a specific namespace even if
 119          *   $text might begin with a namespace prefix, use makeTitle() or
 120          *   makeTitleSafe().
 121          * @return Title, or null on an error.
 122          */
 123         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 124                 if ( is_object( $text ) ) {
 125                         throw new MWException( 'Title::newFromText given an object' );
 126                 }
 127
 128                 /**
 129                  * Wiki pages often contain multiple links to the same page.
 130                  * Title normalization and parsing can become expensive on
 131                  * pages with many links, so we can save a little time by
 132                  * caching them.
 133                  *
 134                  * In theory these are value objects and won't get changed...
 135                  */
 136                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 137                         return Title::$titleCache[$text];
 138                 }
 139
 140                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 141                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 142
 143                 $t = new Title();
 144                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 145                 $t->mDefaultNamespace = $defaultNamespace;
 146
 147                 static $cachedcount = 0 ;
 148                 if ( $t->secureAndSplit() ) {
 149                         if ( $defaultNamespace == NS_MAIN ) {
 150                                 if ( $cachedcount >= self::CACHE_MAX ) {
 151                                         # Avoid memory leaks on mass operations...
 152                                         Title::$titleCache = array();
 153                                         $cachedcount = 0;
 154                                 }
 155                                 $cachedcount++;
 156                                 Title::$titleCache[$text] =& $t;
 157                         }
 158                         return $t;
 159                 } else {
 160                         $ret = null;
 161                         return $ret;
 162                 }
 163         }
 164
 165         /**
 166          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 167          *
 168          * Example of wrong and broken code:
 169          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 170          *
 171          * Example of right code:
 172          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 173          *
 174          * Create a new Title from URL-encoded text. Ensures that
 175          * the given title's length does not exceed the maximum.
 176          *
 177          * @param $url String the title, as might be taken from a URL
 178          * @return Title the new object, or NULL on an error
 179          */
 180         public static function newFromURL( $url ) {
 181                 global $wgLegalTitleChars;
 182                 $t = new Title();
 183
 184                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 185                 # but some URLs used it as a space replacement and they still come
 186                 # from some external search tools.
 187                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 188                         $url = str_replace( '+', ' ', $url );
 189                 }
 190
 191                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 192                 if ( $t->secureAndSplit() ) {
 193                         return $t;
 194                 } else {
 195                         return null;
 196                 }
 197         }
 198
 199         /**
 200          * Create a new Title from an article ID
 201          *
 202          * @param $id Int the page_id corresponding to the Title to create
 203          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 204          * @return Title the new object, or NULL on an error
 205          */
 206         public static function newFromID( $id, $flags = 0 ) {
 207                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 208                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 209                 if ( $row !== false ) {
 210                         $title = Title::newFromRow( $row );
 211                 } else {
 212                         $title = null;
 213                 }
 214                 return $title;
 215         }
 216
 217         /**
 218          * Make an array of titles from an array of IDs
 219          *
 220          * @param $ids Array of Int Array of IDs
 221          * @return Array of Titles
 222          */
 223         public static function newFromIDs( $ids ) {
 224                 if ( !count( $ids ) ) {
 225                         return array();
 226                 }
 227                 $dbr = wfGetDB( DB_SLAVE );
 228
 229                 $res = $dbr->select(
 230                         'page',
 231                         array(
 232                                 'page_namespace', 'page_title', 'page_id',
 233                                 'page_len', 'page_is_redirect', 'page_latest',
 234                         ),
 235                         array( 'page_id' => $ids ),
 236                         __METHOD__
 237                 );
 238
 239                 $titles = array();
 240                 foreach ( $res as $row ) {
 241                         $titles[] = Title::newFromRow( $row );
 242                 }
 243                 return $titles;
 244         }
 245
 246         /**
 247          * Make a Title object from a DB row
 248          *
 249          * @param $row Object database row (needs at least page_title,page_namespace)
 250          * @return Title corresponding Title
 251          */
 252         public static function newFromRow( $row ) {
 253                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 254                 $t->loadFromRow( $row );
 255                 return $t;
 256         }
 257
 258         /**
 259          * Load Title object fields from a DB row.
 260          * If false is given, the title will be treated as non-existing.
 261          *
 262          * @param $row Object|false database row
 263          * @return void
 264          */
 265         public function loadFromRow( $row ) {
 266                 if ( $row ) { // page found
 267                         if ( isset( $row->page_id ) )
 268                                 $this->mArticleID = (int)$row->page_id;
 269                         if ( isset( $row->page_len ) )
 270                                 $this->mLength = (int)$row->page_len;
 271                         if ( isset( $row->page_is_redirect ) )
 272                                 $this->mRedirect = (bool)$row->page_is_redirect;
 273                         if ( isset( $row->page_latest ) )
 274                                 $this->mLatestID = (int)$row->page_latest;
 275                 } else { // page not found
 276                         $this->mArticleID = 0;
 277                         $this->mLength = 0;
 278                         $this->mRedirect = false;
 279                         $this->mLatestID = 0;
 280                 }
 281         }
 282
 283         /**
 284          * Create a new Title from a namespace index and a DB key.
 285          * It's assumed that $ns and $title are *valid*, for instance when
 286          * they came directly from the database or a special page name.
 287          * For convenience, spaces are converted to underscores so that
 288          * eg user_text fields can be used directly.
 289          *
 290          * @param $ns Int the namespace of the article
 291          * @param $title String the unprefixed database key form
 292          * @param $fragment String the link fragment (after the "#")
 293          * @param $interwiki String the interwiki prefix
 294          * @return Title the new object
 295          */
 296         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 297                 $t = new Title();
 298                 $t->mInterwiki = $interwiki;
 299                 $t->mFragment = $fragment;
 300                 $t->mNamespace = $ns = intval( $ns );
 301                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 302                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 303                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 304                 $t->mTextform = str_replace( '_', ' ', $title );
 305                 return $t;
 306         }
 307
 308         /**
 309          * Create a new Title from a namespace index and a DB key.
 310          * The parameters will be checked for validity, which is a bit slower
 311          * than makeTitle() but safer for user-provided data.
 312          *
 313          * @param $ns Int the namespace of the article
 314          * @param $title String database key form
 315          * @param $fragment String the link fragment (after the "#")
 316          * @param $interwiki String interwiki prefix
 317          * @return Title the new object, or NULL on an error
 318          */
 319         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 320                 $t = new Title();
 321                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 322                 if ( $t->secureAndSplit() ) {
 323                         return $t;
 324                 } else {
 325                         return null;
 326                 }
 327         }
 328
 329         /**
 330          * Create a new Title for the Main Page
 331          *
 332          * @return Title the new object
 333          */
 334         public static function newMainPage() {
 335                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 336                 // Don't give fatal errors if the message is broken
 337                 if ( !$title ) {
 338                         $title = Title::newFromText( 'Main Page' );
 339                 }
 340                 return $title;
 341         }
 342
 343         /**
 344          * Extract a redirect destination from a string and return the
 345          * Title, or null if the text doesn't contain a valid redirect
 346          * This will only return the very next target, useful for
 347          * the redirect table and other checks that don't need full recursion
 348          *
 349          * @param $text String: Text with possible redirect
 350          * @return Title: The corresponding Title
 351          */
 352         public static function newFromRedirect( $text ) {
 353                 return self::newFromRedirectInternal( $text );
 354         }
 355
 356         /**
 357          * Extract a redirect destination from a string and return the
 358          * Title, or null if the text doesn't contain a valid redirect
 359          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 360          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 361          *
 362          * @param $text String Text with possible redirect
 363          * @return Title
 364          */
 365         public static function newFromRedirectRecurse( $text ) {
 366                 $titles = self::newFromRedirectArray( $text );
 367                 return $titles ? array_pop( $titles ) : null;
 368         }
 369
 370         /**
 371          * Extract a redirect destination from a string and return an
 372          * array of Titles, or null if the text doesn't contain a valid redirect
 373          * The last element in the array is the final destination after all redirects
 374          * have been resolved (up to $wgMaxRedirects times)
 375          *
 376          * @param $text String Text with possible redirect
 377          * @return Array of Titles, with the destination last
 378          */
 379         public static function newFromRedirectArray( $text ) {
 380                 global $wgMaxRedirects;
 381                 $title = self::newFromRedirectInternal( $text );
 382                 if ( is_null( $title ) ) {
 383                         return null;
 384                 }
 385                 // recursive check to follow double redirects
 386                 $recurse = $wgMaxRedirects;
 387                 $titles = array( $title );
 388                 while ( --$recurse > 0 ) {
 389                         if ( $title->isRedirect() ) {
 390                                 $article = new Article( $title, 0 );
 391                                 $newtitle = $article->getRedirectTarget();
 392                         } else {
 393                                 break;
 394                         }
 395                         // Redirects to some special pages are not permitted
 396                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 397                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 398                                 $title = $newtitle;
 399                                 $titles[] = $newtitle;
 400                         } else {
 401                                 break;
 402                         }
 403                 }
 404                 return $titles;
 405         }
 406
 407         /**
 408          * Really extract the redirect destination
 409          * Do not call this function directly, use one of the newFromRedirect* functions above
 410          *
 411          * @param $text String Text with possible redirect
 412          * @return Title
 413          */
 414         protected static function newFromRedirectInternal( $text ) {
 415                 global $wgMaxRedirects;
 416                 if ( $wgMaxRedirects < 1 ) {
 417                         //redirects are disabled, so quit early
 418                         return null;
 419                 }
 420                 $redir = MagicWord::get( 'redirect' );
 421                 $text = trim( $text );
 422                 if ( $redir->matchStartAndRemove( $text ) ) {
 423                         // Extract the first link and see if it's usable
 424                         // Ensure that it really does come directly after #REDIRECT
 425                         // Some older redirects included a colon, so don't freak about that!
 426                         $m = array();
 427                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 428                                 // Strip preceding colon used to "escape" categories, etc.
 429                                 // and URL-decode links
 430                                 if ( strpos( $m[1], '%' ) !== false ) {
 431                                         // Match behavior of inline link parsing here;
 432                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 433                                 }
 434                                 $title = Title::newFromText( $m[1] );
 435                                 // If the title is a redirect to bad special pages or is invalid, return null
 436                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 437                                         return null;
 438                                 }
 439                                 return $title;
 440                         }
 441                 }
 442                 return null;
 443         }
 444
 445 # ----------------------------------------------------------------------------
 446 #       Static functions
 447 # ----------------------------------------------------------------------------
 448
 449         /**
 450          * Get the prefixed DB key associated with an ID
 451          *
 452          * @param $id Int the page_id of the article
 453          * @return Title an object representing the article, or NULL if no such article was found
 454          */
 455         public static function nameOf( $id ) {
 456                 $dbr = wfGetDB( DB_SLAVE );
 457
 458                 $s = $dbr->selectRow(
 459                         'page',
 460                         array( 'page_namespace', 'page_title' ),
 461                         array( 'page_id' => $id ),
 462                         __METHOD__
 463                 );
 464                 if ( $s === false ) {
 465                         return null;
 466                 }
 467
 468                 $n = self::makeName( $s->page_namespace, $s->page_title );
 469                 return $n;
 470         }
 471
 472         /**
 473          * Get a regex character class describing the legal characters in a link
 474          *
 475          * @return String the list of characters, not delimited
 476          */
 477         public static function legalChars() {
 478                 global $wgLegalTitleChars;
 479                 return $wgLegalTitleChars;
 480         }
 481
 482         /**
 483          * Get a string representation of a title suitable for
 484          * including in a search index
 485          *
 486          * @param $ns Int a namespace index
 487          * @param $title String text-form main part
 488          * @return String a stripped-down title string ready for the search index
 489          */
 490         public static function indexTitle( $ns, $title ) {
 491                 global $wgContLang;
 492
 493                 $lc = SearchEngine::legalSearchChars() . '&#;';
 494                 $t = $wgContLang->normalizeForSearch( $title );
 495                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 496                 $t = $wgContLang->lc( $t );
 497
 498                 # Handle 's, s'
 499                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 500                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 501
 502                 $t = preg_replace( "/\\s+/", ' ', $t );
 503
 504                 if ( $ns == NS_FILE ) {
 505                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 506                 }
 507                 return trim( $t );
 508         }
 509
 510         /**
 511          * Make a prefixed DB key from a DB key and a namespace index
 512          *
 513          * @param $ns Int numerical representation of the namespace
 514          * @param $title String the DB key form the title
 515          * @param $fragment String The link fragment (after the "#")
 516          * @param $interwiki String The interwiki prefix
 517          * @return String the prefixed form of the title
 518          */
 519         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 520                 global $wgContLang;
 521
 522                 $namespace = $wgContLang->getNsText( $ns );
 523                 $name = $namespace == '' ? $title : "$namespace:$title";
 524                 if ( strval( $interwiki ) != '' ) {
 525                         $name = "$interwiki:$name";
 526                 }
 527                 if ( strval( $fragment ) != '' ) {
 528                         $name .= '#' . $fragment;
 529                 }
 530                 return $name;
 531         }
 532
 533         /**
 534          * Determine whether the object refers to a page within
 535          * this project.
 536          *
 537          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 538          */
 539         public function isLocal() {
 540                 if ( $this->mInterwiki != '' ) {
 541                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 542                 } else {
 543                         return true;
 544                 }
 545         }
 546
 547         /**
 548          * Determine whether the object refers to a page within
 549          * this project and is transcludable.
 550          *
 551          * @return Bool TRUE if this is transcludable
 552          */
 553         public function isTrans() {
 554                 if ( $this->mInterwiki == '' ) {
 555                         return false;
 556                 }
 557
 558                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 559         }
 560
 561         /**
 562          * Returns the DB name of the distant wiki which owns the object.
 563          *
 564          * @return String the DB name
 565          */
 566         public function getTransWikiID() {
 567                 if ( $this->mInterwiki == '' ) {
 568                         return false;
 569                 }
 570
 571                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 572         }
 573
 574         /**
 575          * Escape a text fragment, say from a link, for a URL
 576          *
 577          * @param $fragment string containing a URL or link fragment (after the "#")
 578          * @return String: escaped string
 579          */
 580         static function escapeFragmentForURL( $fragment ) {
 581                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 582                 # fragments appear not to work in IE (at least up to 7) or in at least
 583                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 584                 # to care if they aren't encoded.
 585                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 586         }
 587
 588 # ----------------------------------------------------------------------------
 589 #       Other stuff
 590 # ----------------------------------------------------------------------------
 591
 592         /** Simple accessors */
 593         /**
 594          * Get the text form (spaces not underscores) of the main part
 595          *
 596          * @return String Main part of the title
 597          */
 598         public function getText() { return $this->mTextform; }
 599
 600         /**
 601          * Get the URL-encoded form of the main part
 602          *
 603          * @return String Main part of the title, URL-encoded
 604          */
 605         public function getPartialURL() { return $this->mUrlform; }
 606
 607         /**
 608          * Get the main part with underscores
 609          *
 610          * @return String: Main part of the title, with underscores
 611          */
 612         public function getDBkey() { return $this->mDbkeyform; }
 613
 614         /**
 615          * Get the namespace index, i.e. one of the NS_xxxx constants.
 616          *
 617          * @return Integer: Namespace index
 618          */
 619         public function getNamespace() { return $this->mNamespace; }
 620
 621         /**
 622          * Get the namespace text
 623          *
 624          * @return String: Namespace text
 625          */
 626         public function getNsText() {
 627                 global $wgContLang;
 628
 629                 if ( $this->mInterwiki != '' ) {
 630                         // This probably shouldn't even happen. ohh man, oh yuck.
 631                         // But for interwiki transclusion it sometimes does.
 632                         // Shit. Shit shit shit.
 633                         //
 634                         // Use the canonical namespaces if possible to try to
 635                         // resolve a foreign namespace.
 636                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 637                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 638                         }
 639                 }
 640
 641                 // Strip off subpages
 642                 $pagename = $this->getText();
 643                 if ( strpos( $pagename, '/' ) !== false ) {
 644                         list( $username , ) = explode( '/', $pagename, 2 );
 645                 } else {
 646                         $username = $pagename;
 647                 }
 648
 649                 if ( $wgContLang->needsGenderDistinction() &&
 650                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 651                         $gender = GenderCache::singleton()->getGenderOf( $username, __METHOD__ );
 652                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 653                 }
 654
 655                 return $wgContLang->getNsText( $this->mNamespace );
 656         }
 657
 658         /**
 659          * Get the DB key with the initial letter case as specified by the user
 660          *
 661          * @return String DB key
 662          */
 663         function getUserCaseDBKey() {
 664                 return $this->mUserCaseDBKey;
 665         }
 666
 667         /**
 668          * Get the namespace text of the subject (rather than talk) page
 669          *
 670          * @return String Namespace text
 671          */
 672         public function getSubjectNsText() {
 673                 global $wgContLang;
 674                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 675         }
 676
 677         /**
 678          * Get the namespace text of the talk page
 679          *
 680          * @return String Namespace text
 681          */
 682         public function getTalkNsText() {
 683                 global $wgContLang;
 684                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 685         }
 686
 687         /**
 688          * Could this title have a corresponding talk page?
 689          *
 690          * @return Bool TRUE or FALSE
 691          */
 692         public function canTalk() {
 693                 return( MWNamespace::canTalk( $this->mNamespace ) );
 694         }
 695
 696         /**
 697          * Get the interwiki prefix (or null string)
 698          *
 699          * @return String Interwiki prefix
 700          */
 701         public function getInterwiki() { return $this->mInterwiki; }
 702
 703         /**
 704          * Get the Title fragment (i.e.\ the bit after the #) in text form
 705          *
 706          * @return String Title fragment
 707          */
 708         public function getFragment() { return $this->mFragment; }
 709
 710         /**
 711          * Get the fragment in URL form, including the "#" character if there is one
 712          * @return String Fragment in URL form
 713          */
 714         public function getFragmentForURL() {
 715                 if ( $this->mFragment == '' ) {
 716                         return '';
 717                 } else {
 718                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 719                 }
 720         }
 721
 722         /**
 723          * Get the default namespace index, for when there is no namespace
 724          *
 725          * @return Int Default namespace index
 726          */
 727         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 728
 729         /**
 730          * Get title for search index
 731          *
 732          * @return String a stripped-down title string ready for the
 733          *  search index
 734          */
 735         public function getIndexTitle() {
 736                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 737         }
 738
 739         /**
 740          * Get the prefixed database key form
 741          *
 742          * @return String the prefixed title, with underscores and
 743          *  any interwiki and namespace prefixes
 744          */
 745         public function getPrefixedDBkey() {
 746                 $s = $this->prefix( $this->mDbkeyform );
 747                 $s = str_replace( ' ', '_', $s );
 748                 return $s;
 749         }
 750
 751         /**
 752          * Get the prefixed title with spaces.
 753          * This is the form usually used for display
 754          *
 755          * @return String the prefixed title, with spaces
 756          */
 757         public function getPrefixedText() {
 758                 // @todo FIXME: Bad usage of empty() ?
 759                 if ( empty( $this->mPrefixedText ) ) {
 760                         $s = $this->prefix( $this->mTextform );
 761                         $s = str_replace( '_', ' ', $s );
 762                         $this->mPrefixedText = $s;
 763                 }
 764                 return $this->mPrefixedText;
 765         }
 766
 767         /**
 768         /**
 769          * Get the prefixed title with spaces, plus any fragment
 770          * (part beginning with '#')
 771          *
 772          * @return String the prefixed title, with spaces and the fragment, including '#'
 773          */
 774         public function getFullText() {
 775                 $text = $this->getPrefixedText();
 776                 if ( $this->mFragment != '' ) {
 777                         $text .= '#' . $this->mFragment;
 778                 }
 779                 return $text;
 780         }
 781
 782         /**
 783          * Get the base page name, i.e. the leftmost part before any slashes
 784          *
 785          * @return String Base name
 786          */
 787         public function getBaseText() {
 788                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 789                         return $this->getText();
 790                 }
 791
 792                 $parts = explode( '/', $this->getText() );
 793                 # Don't discard the real title if there's no subpage involved
 794                 if ( count( $parts ) > 1 ) {
 795                         unset( $parts[count( $parts ) - 1] );
 796                 }
 797                 return implode( '/', $parts );
 798         }
 799
 800         /**
 801          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
 802          *
 803          * @return String Subpage name
 804          */
 805         public function getSubpageText() {
 806                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 807                         return( $this->mTextform );
 808                 }
 809                 $parts = explode( '/', $this->mTextform );
 810                 return( $parts[count( $parts ) - 1] );
 811         }
 812
 813         /**
 814          * Get a URL-encoded form of the subpage text
 815          *
 816          * @return String URL-encoded subpage name
 817          */
 818         public function getSubpageUrlForm() {
 819                 $text = $this->getSubpageText();
 820                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 821                 return( $text );
 822         }
 823
 824         /**
 825          * Get a URL-encoded title (not an actual URL) including interwiki
 826          *
 827          * @return String the URL-encoded form
 828          */
 829         public function getPrefixedURL() {
 830                 $s = $this->prefix( $this->mDbkeyform );
 831                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 832                 return $s;
 833         }
 834
 835         /**
 836          * Get a real URL referring to this title, with interwiki link and
 837          * fragment
 838          *
 839          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 840          *   links. Can be specified as an associative array as well, e.g.,
 841          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 842          * @param $variant String language variant of url (for sr, zh..)
 843          * @return String the URL
 844          */
 845         public function getFullURL( $query = '', $variant = false ) {
 846                 global $wgServer, $wgRequest;
 847
 848                 # Hand off all the decisions on urls to getLocalURL
 849                 $url = $this->getLocalURL( $query, $variant );
 850
 851                 # Expand the url to make it a full url. Note that getLocalURL has the
 852                 # potential to output full urls for a variety of reasons, so we use
 853                 # wfExpandUrl instead of simply prepending $wgServer
 854                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
 855
 856                 # Finally, add the fragment.
 857                 $url .= $this->getFragmentForURL();
 858
 859                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query, $variant ) );
 860                 return $url;
 861         }
 862
 863         /**
 864          * Get a URL with no fragment or server name.  If this page is generated
 865          * with action=render, $wgServer is prepended.
 866          *
 867          * @param $query Mixed: an optional query string; if not specified,
 868          *   $wgArticlePath will be used.  Can be specified as an associative array
 869          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 870          *   URL-escaped).
 871          * @param $variant String language variant of url (for sr, zh..)
 872          * @return String the URL
 873          */
 874         public function getLocalURL( $query = '', $variant = false ) {
 875                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 876                 global $wgVariantArticlePath;
 877
 878                 if ( is_array( $query ) ) {
 879                         $query = wfArrayToCGI( $query );
 880                 }
 881
 882                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 883                 if ( $interwiki ) {
 884                         $namespace = $this->getNsText();
 885                         if ( $namespace != '' ) {
 886                                 # Can this actually happen? Interwikis shouldn't be parsed.
 887                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 888                                 $namespace .= ':';
 889                         }
 890                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 891                         $url = wfAppendQuery( $url, $query );
 892                 } else {
 893                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 894                         if ( $query == '' ) {
 895                                 if ( $variant != false && $this->getPageLanguage()->hasVariants() ) {
 896                                         if ( !$wgVariantArticlePath ) {
 897                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 898                                         } else {
 899                                                 $variantArticlePath = $wgVariantArticlePath;
 900                                         }
 901                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 902                                         $url = str_replace( '$1', $dbkey, $url  );
 903                                 } else {
 904                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 905                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
 906                                 }
 907                         } else {
 908                                 global $wgActionPaths;
 909                                 $url = false;
 910                                 $matches = array();
 911                                 if ( !empty( $wgActionPaths ) &&
 912                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 913                                 {
 914                                         $action = urldecode( $matches[2] );
 915                                         if ( isset( $wgActionPaths[$action] ) ) {
 916                                                 $query = $matches[1];
 917                                                 if ( isset( $matches[4] ) ) {
 918                                                         $query .= $matches[4];
 919                                                 }
 920                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 921                                                 if ( $query != '' ) {
 922                                                         $url = wfAppendQuery( $url, $query );
 923                                                 }
 924                                         }
 925                                 }
 926
 927                                 if ( $url === false ) {
 928                                         if ( $query == '-' ) {
 929                                                 $query = '';
 930                                         }
 931                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 932                                 }
 933                         }
 934
 935                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
 936
 937                         // @todo FIXME: This causes breakage in various places when we
 938                         // actually expected a local URL and end up with dupe prefixes.
 939                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 940                                 $url = $wgServer . $url;
 941                         }
 942                 }
 943                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
 944                 return $url;
 945         }
 946
 947         /**
 948          * Get a URL that's the simplest URL that will be valid to link, locally,
 949          * to the current Title.  It includes the fragment, but does not include
 950          * the server unless action=render is used (or the link is external).  If
 951          * there's a fragment but the prefixed text is empty, we just return a link
 952          * to the fragment.
 953          *
 954          * The result obviously should not be URL-escaped, but does need to be
 955          * HTML-escaped if it's being output in HTML.
 956          *
 957          * @param $query Array of Strings An associative array of key => value pairs for the
 958          *   query string.  Keys and values will be escaped.
 959          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 960          *   for external links.  Default is "false" (same variant as current page,
 961          *   for anonymous users).
 962          * @return String the URL
 963          */
 964         public function getLinkUrl( $query = array(), $variant = false ) {
 965                 wfProfileIn( __METHOD__ );
 966                 if ( $this->isExternal() ) {
 967                         $ret = $this->getFullURL( $query );
 968                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 969                         $ret = $this->getFragmentForURL();
 970                 } else {
 971                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 972                 }
 973                 wfProfileOut( __METHOD__ );
 974                 return $ret;
 975         }
 976
 977         /**
 978          * Get an HTML-escaped version of the URL form, suitable for
 979          * using in a link, without a server name or fragment
 980          *
 981          * @param $query String an optional query string
 982          * @return String the URL
 983          */
 984         public function escapeLocalURL( $query = '' ) {
 985                 return htmlspecialchars( $this->getLocalURL( $query ) );
 986         }
 987
 988         /**
 989          * Get an HTML-escaped version of the URL form, suitable for
 990          * using in a link, including the server name and fragment
 991          *
 992          * @param $query String an optional query string
 993          * @return String the URL
 994          */
 995         public function escapeFullURL( $query = '' ) {
 996                 return htmlspecialchars( $this->getFullURL( $query ) );
 997         }
 998
 999         /**
1000          * HTML-escaped version of getCanonicalURL()
1001          */
1002         public function escapeCanonicalURL( $query = '', $variant = false ) {
1003                 return htmlspecialchars( $this->getCanonicalURL( $query, $variant ) );
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          * This uses $wgInternalServer to qualify the path, or $wgServer
1012          * if $wgInternalServer is not set. If the server variable used is
1013          * protocol-relative, the URL will be expanded to http://
1014          *
1015          * @param $query String an optional query string
1016          * @param $variant String language variant of url (for sr, zh..)
1017          * @return String the URL
1018          */
1019         public function getInternalURL( $query = '', $variant = false ) {
1020                 global $wgInternalServer, $wgServer;
1021                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1022                 $url = wfExpandUrl( $server . $this->getLocalURL( $query, $variant ), PROTO_HTTP );
1023                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query, $variant ) );
1024                 return $url;
1025         }
1026
1027         /**
1028          * Get the URL for a canonical link, for use in things like IRC and
1029          * e-mail notifications. Uses $wgCanonicalServer and the
1030          * GetCanonicalURL hook.
1031          *
1032          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1033          *
1034          * @param $query string An optional query string
1035          * @param $variant string Language variant of URL (for sr, zh, ...)
1036          * @return string The URL
1037          */
1038         public function getCanonicalURL( $query = '', $variant = false ) {
1039                 $url = wfExpandUrl( $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1040                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query, $variant ) );
1041                 return $url;
1042         }
1043
1044         /**
1045          * Get the edit URL for this Title
1046          *
1047          * @return String the URL, or a null string if this is an
1048          *  interwiki link
1049          */
1050         public function getEditURL() {
1051                 if ( $this->mInterwiki != '' ) {
1052                         return '';
1053                 }
1054                 $s = $this->getLocalURL( 'action=edit' );
1055
1056                 return $s;
1057         }
1058
1059         /**
1060          * Get the HTML-escaped displayable text form.
1061          * Used for the title field in <a> tags.
1062          *
1063          * @return String the text, including any prefixes
1064          */
1065         public function getEscapedText() {
1066                 return htmlspecialchars( $this->getPrefixedText() );
1067         }
1068
1069         /**
1070          * Is this Title interwiki?
1071          *
1072          * @return Bool
1073          */
1074         public function isExternal() {
1075                 return ( $this->mInterwiki != '' );
1076         }
1077
1078         /**
1079          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1080          *
1081          * @param $action String Action to check (default: edit)
1082          * @return Bool
1083          */
1084         public function isSemiProtected( $action = 'edit' ) {
1085                 if ( $this->exists() ) {
1086                         $restrictions = $this->getRestrictions( $action );
1087                         if ( count( $restrictions ) > 0 ) {
1088                                 foreach ( $restrictions as $restriction ) {
1089                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1090                                                 return false;
1091                                         }
1092                                 }
1093                         } else {
1094                                 # Not protected
1095                                 return false;
1096                         }
1097                         return true;
1098                 } else {
1099                         # If it doesn't exist, it can't be protected
1100                         return false;
1101                 }
1102         }
1103
1104         /**
1105          * Does the title correspond to a protected article?
1106          *
1107          * @param $action String the action the page is protected from,
1108          * by default checks all actions.
1109          * @return Bool
1110          */
1111         public function isProtected( $action = '' ) {
1112                 global $wgRestrictionLevels;
1113
1114                 $restrictionTypes = $this->getRestrictionTypes();
1115
1116                 # Special pages have inherent protection
1117                 if( $this->getNamespace() == NS_SPECIAL ) {
1118                         return true;
1119                 }
1120
1121                 # Check regular protection levels
1122                 foreach ( $restrictionTypes as $type ) {
1123                         if ( $action == $type || $action == '' ) {
1124                                 $r = $this->getRestrictions( $type );
1125                                 foreach ( $wgRestrictionLevels as $level ) {
1126                                         if ( in_array( $level, $r ) && $level != '' ) {
1127                                                 return true;
1128                                         }
1129                                 }
1130                         }
1131                 }
1132
1133                 return false;
1134         }
1135
1136         /**
1137          * Is this a conversion table for the LanguageConverter?
1138          *
1139          * @return Bool
1140          */
1141         public function isConversionTable() {
1142                 if(
1143                         $this->getNamespace() == NS_MEDIAWIKI &&
1144                         strpos( $this->getText(), 'Conversiontable' ) !== false
1145                 )
1146                 {
1147                         return true;
1148                 }
1149
1150                 return false;
1151         }
1152
1153         /**
1154          * Is $wgUser watching this page?
1155          *
1156          * @return Bool
1157          */
1158         public function userIsWatching() {
1159                 global $wgUser;
1160
1161                 if ( is_null( $this->mWatched ) ) {
1162                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1163                                 $this->mWatched = false;
1164                         } else {
1165                                 $this->mWatched = $wgUser->isWatched( $this );
1166                         }
1167                 }
1168                 return $this->mWatched;
1169         }
1170
1171         /**
1172          * Can $wgUser perform $action on this page?
1173          * This skips potentially expensive cascading permission checks
1174          * as well as avoids expensive error formatting
1175          *
1176          * Suitable for use for nonessential UI controls in common cases, but
1177          * _not_ for functional access control.
1178          *
1179          * May provide false positives, but should never provide a false negative.
1180          *
1181          * @param $action String action that permission needs to be checked for
1182          * @return Bool
1183          */
1184         public function quickUserCan( $action ) {
1185                 return $this->userCan( $action, false );
1186         }
1187
1188         /**
1189          * Determines if $user is unable to edit this page because it has been protected
1190          * by $wgNamespaceProtection.
1191          *
1192          * @param $user User object to check permissions
1193          * @return Bool
1194          */
1195         public function isNamespaceProtected( User $user ) {
1196                 global $wgNamespaceProtection;
1197
1198                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1199                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1200                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1201                                         return true;
1202                                 }
1203                         }
1204                 }
1205                 return false;
1206         }
1207
1208         /**
1209          * Can $wgUser perform $action on this page?
1210          *
1211          * @param $action String action that permission needs to be checked for
1212          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1213          * @return Bool
1214          */
1215         public function userCan( $action, $doExpensiveQueries = true ) {
1216                 global $wgUser;
1217                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1218         }
1219
1220         /**
1221          * Can $user perform $action on this page?
1222          *
1223          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1224          *
1225          * @param $action String action that permission needs to be checked for
1226          * @param $user User to check
1227          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1228          *   skipping checks for cascading protections and user blocks.
1229          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1230          * @return Array of arguments to wfMsg to explain permissions problems.
1231          */
1232         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1233                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1234
1235                 // Remove the errors being ignored.
1236                 foreach ( $errors as $index => $error ) {
1237                         $error_key = is_array( $error ) ? $error[0] : $error;
1238
1239                         if ( in_array( $error_key, $ignoreErrors ) ) {
1240                                 unset( $errors[$index] );
1241                         }
1242                 }
1243
1244                 return $errors;
1245         }
1246
1247         /**
1248          * Permissions checks that fail most often, and which are easiest to test.
1249          *
1250          * @param $action String the action to check
1251          * @param $user User user to check
1252          * @param $errors Array list of current errors
1253          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1254          * @param $short Boolean short circuit on first error
1255          *
1256          * @return Array list of errors
1257          */
1258         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1259                 $ns = $this->getNamespace();
1260
1261                 if ( $action == 'create' ) {
1262                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1263                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1264                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1265                         }
1266                 } elseif ( $action == 'move' ) {
1267                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1268                                         && $ns == NS_USER && !$this->isSubpage() ) {
1269                                 // Show user page-specific message only if the user can move other pages
1270                                 $errors[] = array( 'cant-move-user-page' );
1271                         }
1272
1273                         // Check if user is allowed to move files if it's a file
1274                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1275                                 $errors[] = array( 'movenotallowedfile' );
1276                         }
1277
1278                         if ( !$user->isAllowed( 'move', $ns) ) {
1279                                 // User can't move anything
1280
1281                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1282                                         array( 'user' ), $ns ), true );
1283                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1284                                         array( 'autoconfirmed' ), $ns ), true );
1285
1286                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1287                                         // custom message if logged-in users without any special rights can move
1288                                         $errors[] = array( 'movenologintext' );
1289                                 } else {
1290                                         $errors[] = array( 'movenotallowed' );
1291                                 }
1292                         }
1293                 } elseif ( $action == 'move-target' ) {
1294                         if ( !$user->isAllowed( 'move', $ns ) ) {
1295                                 // User can't move anything
1296                                 $errors[] = array( 'movenotallowed' );
1297                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1298                                         && $ns == NS_USER && !$this->isSubpage() ) {
1299                                 // Show user page-specific message only if the user can move other pages
1300                                 $errors[] = array( 'cant-move-to-user-page' );
1301                         }
1302                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1303                         // We avoid expensive display logic for quickUserCan's and such
1304                         $groups = false;
1305                         if ( !$short ) {
1306                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1307                                         User::getGroupsWithPermission( $action, $ns ) );
1308                         }
1309
1310                         if ( $groups ) {
1311                                 global $wgLang;
1312                                 $return = array(
1313                                         'badaccess-groups',
1314                                         $wgLang->commaList( $groups ),
1315                                         count( $groups )
1316                                 );
1317                         } else {
1318                                 $return = array( 'badaccess-group0' );
1319                         }
1320                         $errors[] = $return;
1321                 }
1322
1323                 return $errors;
1324         }
1325
1326         /**
1327          * Add the resulting error code to the errors array
1328          *
1329          * @param $errors Array list of current errors
1330          * @param $result Mixed result of errors
1331          *
1332          * @return Array list of errors
1333          */
1334         private function resultToError( $errors, $result ) {
1335                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1336                         // A single array representing an error
1337                         $errors[] = $result;
1338                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1339                         // A nested array representing multiple errors
1340                         $errors = array_merge( $errors, $result );
1341                 } elseif ( $result !== '' && is_string( $result ) ) {
1342                         // A string representing a message-id
1343                         $errors[] = array( $result );
1344                 } elseif ( $result === false ) {
1345                         // a generic "We don't want them to do that"
1346                         $errors[] = array( 'badaccess-group0' );
1347                 }
1348                 return $errors;
1349         }
1350
1351         /**
1352          * Check various permission hooks
1353          *
1354          * @param $action String the action to check
1355          * @param $user User user to check
1356          * @param $errors Array list of current errors
1357          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1358          * @param $short Boolean short circuit on first error
1359          *
1360          * @return Array list of errors
1361          */
1362         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1363                 // Use getUserPermissionsErrors instead
1364                 $result = '';
1365                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1366                         return $result ? array() : array( array( 'badaccess-group0' ) );
1367                 }
1368                 // Check getUserPermissionsErrors hook
1369                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1370                         $errors = $this->resultToError( $errors, $result );
1371                 }
1372                 // Check getUserPermissionsErrorsExpensive hook
1373                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1374                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1375                         $errors = $this->resultToError( $errors, $result );
1376                 }
1377
1378                 return $errors;
1379         }
1380
1381         /**
1382          * Check permissions on special pages & namespaces
1383          *
1384          * @param $action String the action to check
1385          * @param $user User user to check
1386          * @param $errors Array list of current errors
1387          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1388          * @param $short Boolean short circuit on first error
1389          *
1390          * @return Array list of errors
1391          */
1392         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1393                 # Only 'createaccount' and 'execute' can be performed on
1394                 # special pages, which don't actually exist in the DB.
1395                 $specialOKActions = array( 'createaccount', 'execute' );
1396                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1397                         $errors[] = array( 'ns-specialprotected' );
1398                 }
1399
1400                 # Check $wgNamespaceProtection for restricted namespaces
1401                 if ( $this->isNamespaceProtected( $user ) ) {
1402                         $ns = $this->mNamespace == NS_MAIN ?
1403                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1404                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1405                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1406                 }
1407
1408                 return $errors;
1409         }
1410
1411         /**
1412          * Check CSS/JS sub-page permissions
1413          *
1414          * @param $action String the action to check
1415          * @param $user User user to check
1416          * @param $errors Array list of current errors
1417          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1418          * @param $short Boolean short circuit on first error
1419          *
1420          * @return Array list of errors
1421          */
1422         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1423                 # Protect css/js subpages of user pages
1424                 # XXX: this might be better using restrictions
1425                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1426                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1427                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1428                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1429                                 $errors[] = array( 'customcssprotected' );
1430                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1431                                 $errors[] = array( 'customjsprotected' );
1432                         }
1433                 }
1434
1435                 return $errors;
1436         }
1437
1438         /**
1439          * Check against page_restrictions table requirements on this
1440          * page. The user must possess all required rights for this
1441          * action.
1442          *
1443          * @param $action String the action to check
1444          * @param $user User user to check
1445          * @param $errors Array list of current errors
1446          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1447          * @param $short Boolean short circuit on first error
1448          *
1449          * @return Array list of errors
1450          */
1451         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1452                 foreach ( $this->getRestrictions( $action ) as $right ) {
1453                         // Backwards compatibility, rewrite sysop -> protect
1454                         if ( $right == 'sysop' ) {
1455                                 $right = 'protect';
1456                         }
1457                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1458                                 // Users with 'editprotected' permission can edit protected pages
1459                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected', $this->mNamespace ) ) {
1460                                         // Users with 'editprotected' permission cannot edit protected pages
1461                                         // with cascading option turned on.
1462                                         if ( $this->mCascadeRestriction ) {
1463                                                 $errors[] = array( 'protectedpagetext', $right );
1464                                         }
1465                                 } else {
1466                                         $errors[] = array( 'protectedpagetext', $right );
1467                                 }
1468                         }
1469                 }
1470
1471                 return $errors;
1472         }
1473
1474         /**
1475          * Check restrictions on cascading pages.
1476          *
1477          * @param $action String the action to check
1478          * @param $user User to check
1479          * @param $errors Array list of current errors
1480          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1481          * @param $short Boolean short circuit on first error
1482          *
1483          * @return Array list of errors
1484          */
1485         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1486                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1487                         # We /could/ use the protection level on the source page, but it's
1488                         # fairly ugly as we have to establish a precedence hierarchy for pages
1489                         # included by multiple cascade-protected pages. So just restrict
1490                         # it to people with 'protect' permission, as they could remove the
1491                         # protection anyway.
1492                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1493                         # Cascading protection depends on more than this page...
1494                         # Several cascading protected pages may include this page...
1495                         # Check each cascading level
1496                         # This is only for protection restrictions, not for all actions
1497                         if ( isset( $restrictions[$action] ) ) {
1498                                 foreach ( $restrictions[$action] as $right ) {
1499                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1500                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1501                                                 $pages = '';
1502                                                 foreach ( $cascadingSources as $page )
1503                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1504                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1505                                         }
1506                                 }
1507                         }
1508                 }
1509
1510                 return $errors;
1511         }
1512
1513         /**
1514          * Check action permissions not already checked in checkQuickPermissions
1515          *
1516          * @param $action String the action to check
1517          * @param $user User to check
1518          * @param $errors Array list of current errors
1519          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1520          * @param $short Boolean short circuit on first error
1521          *
1522          * @return Array list of errors
1523          */
1524         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1525                 if ( $action == 'protect' ) {
1526                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1527                                 // If they can't edit, they shouldn't protect.
1528                                 $errors[] = array( 'protect-cantedit' );
1529                         }
1530                 } elseif ( $action == 'create' ) {
1531                         $title_protection = $this->getTitleProtection();
1532                         if( $title_protection ) {
1533                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1534                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1535                                 }
1536                                 if( $title_protection['pt_create_perm'] == '' ||
1537                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1538                                                 $this->mNamespace ) ) {
1539                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1540                                 }
1541                         }
1542                 } elseif ( $action == 'move' ) {
1543                         // Check for immobile pages
1544                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1545                                 // Specific message for this case
1546                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1547                         } elseif ( !$this->isMovable() ) {
1548                                 // Less specific message for rarer cases
1549                                 $errors[] = array( 'immobile-source-page' );
1550                         }
1551                 } elseif ( $action == 'move-target' ) {
1552                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1553                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1554                         } elseif ( !$this->isMovable() ) {
1555                                 $errors[] = array( 'immobile-target-page' );
1556                         }
1557                 }
1558                 return $errors;
1559         }
1560
1561         /**
1562          * Check that the user isn't blocked from editting.
1563          *
1564          * @param $action String the action to check
1565          * @param $user User to check
1566          * @param $errors Array list of current errors
1567          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1568          * @param $short Boolean short circuit on first error
1569          *
1570          * @return Array list of errors
1571          */
1572         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1573                 if( !$doExpensiveQueries ) {
1574                         return $errors;
1575                 }
1576
1577                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1578
1579                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1580                         $errors[] = array( 'confirmedittext' );
1581                 }
1582
1583                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1584                         // Edit blocks should not affect reading.
1585                         // Account creation blocks handled at userlogin.
1586                         // Unblocking handled in SpecialUnblock
1587                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1588                         // Don't block the user from editing their own talk page unless they've been
1589                         // explicitly blocked from that too.
1590                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1591                         $block = $user->mBlock;
1592
1593                         // This is from OutputPage::blockedPage
1594                         // Copied at r23888 by werdna
1595
1596                         $id = $user->blockedBy();
1597                         $reason = $user->blockedFor();
1598                         if ( $reason == '' ) {
1599                                 $reason = wfMsg( 'blockednoreason' );
1600                         }
1601                         $ip = $user->getRequest()->getIP();
1602
1603                         if ( is_numeric( $id ) ) {
1604                                 $name = User::whoIs( $id );
1605                         } else {
1606                                 $name = $id;
1607                         }
1608
1609                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1610                         $blockid = $block->getId();
1611                         $blockExpiry = $user->mBlock->mExpiry;
1612                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1613                         if ( $blockExpiry == 'infinity' ) {
1614                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1615                         } else {
1616                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1617                         }
1618
1619                         $intended = strval( $user->mBlock->getTarget() );
1620
1621                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1622                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1623                 }
1624
1625                 return $errors;
1626         }
1627
1628         /**
1629          * Can $user perform $action on this page? This is an internal function,
1630          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1631          * checks on wfReadOnly() and blocks)
1632          *
1633          * @param $action String action that permission needs to be checked for
1634          * @param $user User to check
1635          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1636          * @param $short Bool Set this to true to stop after the first permission error.
1637          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1638          */
1639         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1640                 wfProfileIn( __METHOD__ );
1641
1642                 $errors = array();
1643                 $checks = array(
1644                         'checkQuickPermissions',
1645                         'checkPermissionHooks',
1646                         'checkSpecialsAndNSPermissions',
1647                         'checkCSSandJSPermissions',
1648                         'checkPageRestrictions',
1649                         'checkCascadingSourcesRestrictions',
1650                         'checkActionPermissions',
1651                         'checkUserBlock'
1652                 );
1653
1654                 while( count( $checks ) > 0 &&
1655                            !( $short && count( $errors ) > 0 ) ) {
1656                         $method = array_shift( $checks );
1657                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1658                 }
1659
1660                 wfProfileOut( __METHOD__ );
1661                 return $errors;
1662         }
1663
1664         /**
1665          * Is this title subject to title protection?
1666          * Title protection is the one applied against creation of such title.
1667          *
1668          * @return Mixed An associative array representing any existent title
1669          *   protection, or false if there's none.
1670          */
1671         private function getTitleProtection() {
1672                 // Can't protect pages in special namespaces
1673                 if ( $this->getNamespace() < 0 ) {
1674                         return false;
1675                 }
1676
1677                 // Can't protect pages that exist.
1678                 if ( $this->exists() ) {
1679                         return false;
1680                 }
1681
1682                 if ( !isset( $this->mTitleProtection ) ) {
1683                         $dbr = wfGetDB( DB_SLAVE );
1684                         $res = $dbr->select( 'protected_titles', '*',
1685                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1686                                 __METHOD__ );
1687
1688                         // fetchRow returns false if there are no rows.
1689                         $this->mTitleProtection = $dbr->fetchRow( $res );
1690                 }
1691                 return $this->mTitleProtection;
1692         }
1693
1694         /**
1695          * Update the title protection status
1696          *
1697          * @param $create_perm String Permission required for creation
1698          * @param $reason String Reason for protection
1699          * @param $expiry String Expiry timestamp
1700          * @return boolean true
1701          */
1702         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1703                 global $wgUser, $wgContLang;
1704
1705                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1706                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1707                         // No change
1708                         return true;
1709                 }
1710
1711                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1712
1713                 $dbw = wfGetDB( DB_MASTER );
1714
1715                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1716
1717                 $expiry_description = '';
1718                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1719                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1720                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1721                 } else {
1722                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1723                 }
1724
1725                 # Update protection table
1726                 if ( $create_perm != '' ) {
1727                         $this->mTitleProtection = array(
1728                                         'pt_namespace' => $namespace,
1729                                         'pt_title' => $title,
1730                                         'pt_create_perm' => $create_perm,
1731                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1732                                         'pt_expiry' => $encodedExpiry,
1733                                         'pt_user' => $wgUser->getId(),
1734                                         'pt_reason' => $reason,
1735                                 );
1736                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1737                                 $this->mTitleProtection, __METHOD__     );
1738                 } else {
1739                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1740                                 'pt_title' => $title ), __METHOD__ );
1741                         $this->mTitleProtection = false;
1742                 }
1743
1744                 # Update the protection log
1745                 if ( $dbw->affectedRows() ) {
1746                         $log = new LogPage( 'protect' );
1747
1748                         if ( $create_perm ) {
1749                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1750                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1751                         } else {
1752                                 $log->addEntry( 'unprotect', $this, $reason );
1753                         }
1754                 }
1755
1756                 return true;
1757         }
1758
1759         /**
1760          * Remove any title protection due to page existing
1761          */
1762         public function deleteTitleProtection() {
1763                 $dbw = wfGetDB( DB_MASTER );
1764
1765                 $dbw->delete(
1766                         'protected_titles',
1767                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1768                         __METHOD__
1769                 );
1770                 $this->mTitleProtection = false;
1771         }
1772
1773         /**
1774          * Would anybody with sufficient privileges be able to move this page?
1775          * Some pages just aren't movable.
1776          *
1777          * @return Bool TRUE or FALSE
1778          */
1779         public function isMovable() {
1780                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
1781                         // Interwiki title or immovable namespace. Hooks don't get to override here
1782                         return false;
1783                 }
1784
1785                 $result = true;
1786                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1787                 return $result;
1788         }
1789
1790         /**
1791          * Can $wgUser read this page?
1792          *
1793          * @return Bool
1794          * @todo fold these checks into userCan()
1795          */
1796         public function userCanRead() {
1797                 global $wgUser, $wgGroupPermissions;
1798
1799                 static $useShortcut = null;
1800
1801                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1802                 if ( is_null( $useShortcut ) ) {
1803                         global $wgRevokePermissions;
1804                         $useShortcut = true;
1805                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1806                                 # Not a public wiki, so no shortcut
1807                                 $useShortcut = false;
1808                         } elseif ( !empty( $wgRevokePermissions ) ) {
1809                                 /**
1810                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1811                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1812                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1813                                  * reading is allowed.
1814                                  */
1815                                 foreach ( $wgRevokePermissions as $perms ) {
1816                                         if ( !empty( $perms['read'] ) ) {
1817                                                 # We might be removing the read right from the user, so no shortcut
1818                                                 $useShortcut = false;
1819                                                 break;
1820                                         }
1821                                 }
1822                         }
1823                 }
1824
1825                 $result = null;
1826                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1827                 if ( $result !== null ) {
1828                         return $result;
1829                 }
1830
1831                 # Shortcut for public wikis, allows skipping quite a bit of code
1832                 if ( $useShortcut ) {
1833                         return true;
1834                 }
1835
1836                 if ( $wgUser->isAllowed( 'read' ) ) {
1837                         return true;
1838                 } else {
1839                         global $wgWhitelistRead;
1840
1841                         # Always grant access to the login page.
1842                         # Even anons need to be able to log in.
1843                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1844                                 return true;
1845                         }
1846
1847                         # Bail out if there isn't whitelist
1848                         if ( !is_array( $wgWhitelistRead ) ) {
1849                                 return false;
1850                         }
1851
1852                         # Check for explicit whitelisting
1853                         $name = $this->getPrefixedText();
1854                         $dbName = $this->getPrefixedDBKey();
1855                         // Check with and without underscores
1856                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1857                                 return true;
1858
1859                         # Old settings might have the title prefixed with
1860                         # a colon for main-namespace pages
1861                         if ( $this->getNamespace() == NS_MAIN ) {
1862                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1863                                         return true;
1864                                 }
1865                         }
1866
1867                         # If it's a special page, ditch the subpage bit and check again
1868                         if ( $this->getNamespace() == NS_SPECIAL ) {
1869                                 $name = $this->getDBkey();
1870                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1871                                 if ( $name === false ) {
1872                                         # Invalid special page, but we show standard login required message
1873                                         return false;
1874                                 }
1875
1876                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1877                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1878                                         return true;
1879                                 }
1880                         }
1881
1882                 }
1883                 return false;
1884         }
1885
1886         /**
1887          * Is this the mainpage?
1888          * @note Title::newFromText seams to be sufficiently optimized by the title
1889          * cache that we don't need to over-optimize by doing direct comparisons and
1890          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1891          * ends up reporting something differently than $title->isMainPage();
1892          *
1893          * @since 1.18
1894          * @return Bool
1895          */
1896         public function isMainPage() {
1897                 return $this->equals( Title::newMainPage() );
1898         }
1899
1900         /**
1901          * Is this a talk page of some sort?
1902          *
1903          * @return Bool
1904          */
1905         public function isTalkPage() {
1906                 return MWNamespace::isTalk( $this->getNamespace() );
1907         }
1908
1909         /**
1910          * Is this a subpage?
1911          *
1912          * @return Bool
1913          */
1914         public function isSubpage() {
1915                 return MWNamespace::hasSubpages( $this->mNamespace )
1916                         ? strpos( $this->getText(), '/' ) !== false
1917                         : false;
1918         }
1919
1920         /**
1921          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1922          *
1923          * @return Bool
1924          */
1925         public function hasSubpages() {
1926                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1927                         # Duh
1928                         return false;
1929                 }
1930
1931                 # We dynamically add a member variable for the purpose of this method
1932                 # alone to cache the result.  There's no point in having it hanging
1933                 # around uninitialized in every Title object; therefore we only add it
1934                 # if needed and don't declare it statically.
1935                 if ( isset( $this->mHasSubpages ) ) {
1936                         return $this->mHasSubpages;
1937                 }
1938
1939                 $subpages = $this->getSubpages( 1 );
1940                 if ( $subpages instanceof TitleArray ) {
1941                         return $this->mHasSubpages = (bool)$subpages->count();
1942                 }
1943                 return $this->mHasSubpages = false;
1944         }
1945
1946         /**
1947          * Get all subpages of this page.
1948          *
1949          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1950          * @return mixed TitleArray, or empty array if this page's namespace
1951          *  doesn't allow subpages
1952          */
1953         public function getSubpages( $limit = -1 ) {
1954                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1955                         return array();
1956                 }
1957
1958                 $dbr = wfGetDB( DB_SLAVE );
1959                 $conds['page_namespace'] = $this->getNamespace();
1960                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1961                 $options = array();
1962                 if ( $limit > -1 ) {
1963                         $options['LIMIT'] = $limit;
1964                 }
1965                 return $this->mSubpages = TitleArray::newFromResult(
1966                         $dbr->select( 'page',
1967                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1968                                 $conds,
1969                                 __METHOD__,
1970                                 $options
1971                         )
1972                 );
1973         }
1974
1975         /**
1976          * Does that page contain wikitext, or it is JS, CSS or whatever?
1977          *
1978          * @return Bool
1979          */
1980         public function isWikitextPage() {
1981                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
1982                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
1983                 return $retval;
1984         }
1985
1986         /**
1987          * Could this page contain custom CSS or JavaScript, based
1988          * on the title?
1989          *
1990          * @return Bool
1991          */
1992         public function isCssOrJsPage() {
1993                 $retval = $this->mNamespace == NS_MEDIAWIKI
1994                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1995                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
1996                 return $retval;
1997         }
1998
1999         /**
2000          * Is this a .css or .js subpage of a user page?
2001          * @return Bool
2002          */
2003         public function isCssJsSubpage() {
2004                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
2005         }
2006
2007         /**
2008          * Is this a *valid* .css or .js subpage of a user page?
2009          *
2010          * @return Bool
2011          * @deprecated since 1.17
2012          */
2013         public function isValidCssJsSubpage() {
2014                 return $this->isCssJsSubpage();
2015         }
2016
2017         /**
2018          * Trim down a .css or .js subpage title to get the corresponding skin name
2019          *
2020          * @return string containing skin name from .css or .js subpage title
2021          */
2022         public function getSkinFromCssJsSubpage() {
2023                 $subpage = explode( '/', $this->mTextform );
2024                 $subpage = $subpage[ count( $subpage ) - 1 ];
2025                 // FIXME: Should only match endings
2026                 // Consider 'Foo/.js.monobook' or 'Foo/mon.js.obook.css'
2027                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
2028         }
2029
2030         /**
2031          * Is this a .css subpage of a user page?
2032          *
2033          * @return Bool
2034          */
2035         public function isCssSubpage() {
2036                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2037         }
2038
2039         /**
2040          * Is this a .js subpage of a user page?
2041          *
2042          * @return Bool
2043          */
2044         public function isJsSubpage() {
2045                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2046         }
2047
2048         /**
2049          * Protect css subpages of user pages: can $wgUser edit
2050          * this page?
2051          *
2052          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2053          * @return Bool
2054          */
2055         public function userCanEditCssSubpage() {
2056                 global $wgUser;
2057                 wfDeprecated( __METHOD__ );
2058                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2059                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2060         }
2061
2062         /**
2063          * Protect js subpages of user pages: can $wgUser edit
2064          * this page?
2065          *
2066          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2067          * @return Bool
2068          */
2069         public function userCanEditJsSubpage() {
2070                 global $wgUser;
2071                 wfDeprecated( __METHOD__ );
2072                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2073                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2074         }
2075
2076         /**
2077          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2078          *
2079          * @return Bool If the page is subject to cascading restrictions.
2080          */
2081         public function isCascadeProtected() {
2082                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2083                 return ( $sources > 0 );
2084         }
2085
2086         /**
2087          * Cascading protection: Get the source of any cascading restrictions on this page.
2088          *
2089          * @param $getPages Bool Whether or not to retrieve the actual pages
2090          *        that the restrictions have come from.
2091          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2092          *     have come, false for none, or true if such restrictions exist, but $getPages
2093          *     was not set.  The restriction array is an array of each type, each of which
2094          *     contains a array of unique groups.
2095          */
2096         public function getCascadeProtectionSources( $getPages = true ) {
2097                 global $wgContLang;
2098                 $pagerestrictions = array();
2099
2100                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2101                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2102                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2103                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2104                 }
2105
2106                 wfProfileIn( __METHOD__ );
2107
2108                 $dbr = wfGetDB( DB_SLAVE );
2109
2110                 if ( $this->getNamespace() == NS_FILE ) {
2111                         $tables = array( 'imagelinks', 'page_restrictions' );
2112                         $where_clauses = array(
2113                                 'il_to' => $this->getDBkey(),
2114                                 'il_from=pr_page',
2115                                 'pr_cascade' => 1
2116                         );
2117                 } else {
2118                         $tables = array( 'templatelinks', 'page_restrictions' );
2119                         $where_clauses = array(
2120                                 'tl_namespace' => $this->getNamespace(),
2121                                 'tl_title' => $this->getDBkey(),
2122                                 'tl_from=pr_page',
2123                                 'pr_cascade' => 1
2124                         );
2125                 }
2126
2127                 if ( $getPages ) {
2128                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2129                                                    'pr_expiry', 'pr_type', 'pr_level' );
2130                         $where_clauses[] = 'page_id=pr_page';
2131                         $tables[] = 'page';
2132                 } else {
2133                         $cols = array( 'pr_expiry' );
2134                 }
2135
2136                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2137
2138                 $sources = $getPages ? array() : false;
2139                 $now = wfTimestampNow();
2140                 $purgeExpired = false;
2141
2142                 foreach ( $res as $row ) {
2143                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2144                         if ( $expiry > $now ) {
2145                                 if ( $getPages ) {
2146                                         $page_id = $row->pr_page;
2147                                         $page_ns = $row->page_namespace;
2148                                         $page_title = $row->page_title;
2149                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2150                                         # Add groups needed for each restriction type if its not already there
2151                                         # Make sure this restriction type still exists
2152
2153                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2154                                                 $pagerestrictions[$row->pr_type] = array();
2155                                         }
2156
2157                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2158                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2159                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2160                                         }
2161                                 } else {
2162                                         $sources = true;
2163                                 }
2164                         } else {
2165                                 // Trigger lazy purge of expired restrictions from the db
2166                                 $purgeExpired = true;
2167                         }
2168                 }
2169                 if ( $purgeExpired ) {
2170                         Title::purgeExpiredRestrictions();
2171                 }
2172
2173                 if ( $getPages ) {
2174                         $this->mCascadeSources = $sources;
2175                         $this->mCascadingRestrictions = $pagerestrictions;
2176                 } else {
2177                         $this->mHasCascadingRestrictions = $sources;
2178                 }
2179
2180                 wfProfileOut( __METHOD__ );
2181                 return array( $sources, $pagerestrictions );
2182         }
2183
2184         /**
2185          * Returns cascading restrictions for the current article
2186          *
2187          * @return Boolean
2188          */
2189         function areRestrictionsCascading() {
2190                 if ( !$this->mRestrictionsLoaded ) {
2191                         $this->loadRestrictions();
2192                 }
2193
2194                 return $this->mCascadeRestriction;
2195         }
2196
2197         /**
2198          * Loads a string into mRestrictions array
2199          *
2200          * @param $res Resource restrictions as an SQL result.
2201          * @param $oldFashionedRestrictions String comma-separated list of page
2202          *        restrictions from page table (pre 1.10)
2203          */
2204         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2205                 $rows = array();
2206
2207                 foreach ( $res as $row ) {
2208                         $rows[] = $row;
2209                 }
2210
2211                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2212         }
2213
2214         /**
2215          * Compiles list of active page restrictions from both page table (pre 1.10)
2216          * and page_restrictions table for this existing page.
2217          * Public for usage by LiquidThreads.
2218          *
2219          * @param $rows array of db result objects
2220          * @param $oldFashionedRestrictions string comma-separated list of page
2221          *        restrictions from page table (pre 1.10)
2222          */
2223         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2224                 global $wgContLang;
2225                 $dbr = wfGetDB( DB_SLAVE );
2226
2227                 $restrictionTypes = $this->getRestrictionTypes();
2228
2229                 foreach ( $restrictionTypes as $type ) {
2230                         $this->mRestrictions[$type] = array();
2231                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2232                 }
2233
2234                 $this->mCascadeRestriction = false;
2235
2236                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2237
2238                 if ( $oldFashionedRestrictions === null ) {
2239                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2240                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2241                 }
2242
2243                 if ( $oldFashionedRestrictions != '' ) {
2244
2245                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2246                                 $temp = explode( '=', trim( $restrict ) );
2247                                 if ( count( $temp ) == 1 ) {
2248                                         // old old format should be treated as edit/move restriction
2249                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2250                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2251                                 } else {
2252                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2253                                 }
2254                         }
2255
2256                         $this->mOldRestrictions = true;
2257
2258                 }
2259
2260                 if ( count( $rows ) ) {
2261                         # Current system - load second to make them override.
2262                         $now = wfTimestampNow();
2263                         $purgeExpired = false;
2264
2265                         # Cycle through all the restrictions.
2266                         foreach ( $rows as $row ) {
2267
2268                                 // Don't take care of restrictions types that aren't allowed
2269                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2270                                         continue;
2271
2272                                 // This code should be refactored, now that it's being used more generally,
2273                                 // But I don't really see any harm in leaving it in Block for now -werdna
2274                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2275
2276                                 // Only apply the restrictions if they haven't expired!
2277                                 if ( !$expiry || $expiry > $now ) {
2278                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2279                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2280
2281                                         $this->mCascadeRestriction |= $row->pr_cascade;
2282                                 } else {
2283                                         // Trigger a lazy purge of expired restrictions
2284                                         $purgeExpired = true;
2285                                 }
2286                         }
2287
2288                         if ( $purgeExpired ) {
2289                                 Title::purgeExpiredRestrictions();
2290                         }
2291                 }
2292
2293                 $this->mRestrictionsLoaded = true;
2294         }
2295
2296         /**
2297          * Load restrictions from the page_restrictions table
2298          *
2299          * @param $oldFashionedRestrictions String comma-separated list of page
2300          *        restrictions from page table (pre 1.10)
2301          */
2302         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2303                 global $wgContLang;
2304                 if ( !$this->mRestrictionsLoaded ) {
2305                         if ( $this->exists() ) {
2306                                 $dbr = wfGetDB( DB_SLAVE );
2307
2308                                 $res = $dbr->select(
2309                                         'page_restrictions',
2310                                         '*',
2311                                         array( 'pr_page' => $this->getArticleId() ),
2312                                         __METHOD__
2313                                 );
2314
2315                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2316                         } else {
2317                                 $title_protection = $this->getTitleProtection();
2318
2319                                 if ( $title_protection ) {
2320                                         $now = wfTimestampNow();
2321                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2322
2323                                         if ( !$expiry || $expiry > $now ) {
2324                                                 // Apply the restrictions
2325                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2326                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2327                                         } else { // Get rid of the old restrictions
2328                                                 Title::purgeExpiredRestrictions();
2329                                                 $this->mTitleProtection = false;
2330                                         }
2331                                 } else {
2332                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2333                                 }
2334                                 $this->mRestrictionsLoaded = true;
2335                         }
2336                 }
2337         }
2338
2339         /**
2340          * Purge expired restrictions from the page_restrictions table
2341          */
2342         static function purgeExpiredRestrictions() {
2343                 $dbw = wfGetDB( DB_MASTER );
2344                 $dbw->delete(
2345                         'page_restrictions',
2346                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2347                         __METHOD__
2348                 );
2349
2350                 $dbw->delete(
2351                         'protected_titles',
2352                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2353                         __METHOD__
2354                 );
2355         }
2356
2357         /**
2358          * Accessor/initialisation for mRestrictions
2359          *
2360          * @param $action String action that permission needs to be checked for
2361          * @return Array of Strings the array of groups allowed to edit this article
2362          */
2363         public function getRestrictions( $action ) {
2364                 if ( !$this->mRestrictionsLoaded ) {
2365                         $this->loadRestrictions();
2366                 }
2367                 return isset( $this->mRestrictions[$action] )
2368                                 ? $this->mRestrictions[$action]
2369                                 : array();
2370         }
2371
2372         /**
2373          * Get the expiry time for the restriction against a given action
2374          *
2375          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2376          *      or not protected at all, or false if the action is not recognised.
2377          */
2378         public function getRestrictionExpiry( $action ) {
2379                 if ( !$this->mRestrictionsLoaded ) {
2380                         $this->loadRestrictions();
2381                 }
2382                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2383         }
2384
2385         /**
2386          * Is there a version of this page in the deletion archive?
2387          *
2388          * @return Int the number of archived revisions
2389          */
2390         public function isDeleted() {
2391                 if ( $this->getNamespace() < 0 ) {
2392                         $n = 0;
2393                 } else {
2394                         $dbr = wfGetDB( DB_SLAVE );
2395
2396                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2397                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2398                                 __METHOD__
2399                         );
2400                         if ( $this->getNamespace() == NS_FILE ) {
2401                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2402                                         array( 'fa_name' => $this->getDBkey() ),
2403                                         __METHOD__
2404                                 );
2405                         }
2406                 }
2407                 return (int)$n;
2408         }
2409
2410         /**
2411          * Is there a version of this page in the deletion archive?
2412          *
2413          * @return Boolean
2414          */
2415         public function isDeletedQuick() {
2416                 if ( $this->getNamespace() < 0 ) {
2417                         return false;
2418                 }
2419                 $dbr = wfGetDB( DB_SLAVE );
2420                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2421                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2422                         __METHOD__
2423                 );
2424                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2425                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2426                                 array( 'fa_name' => $this->getDBkey() ),
2427                                 __METHOD__
2428                         );
2429                 }
2430                 return $deleted;
2431         }
2432
2433         /**
2434          * Get the article ID for this Title from the link cache,
2435          * adding it if necessary
2436          *
2437          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2438          *  for update
2439          * @return Int the ID
2440          */
2441         public function getArticleID( $flags = 0 ) {
2442                 if ( $this->getNamespace() < 0 ) {
2443                         return $this->mArticleID = 0;
2444                 }
2445                 $linkCache = LinkCache::singleton();
2446                 if ( $flags & self::GAID_FOR_UPDATE ) {
2447                         $oldUpdate = $linkCache->forUpdate( true );
2448                         $linkCache->clearLink( $this );
2449                         $this->mArticleID = $linkCache->addLinkObj( $this );
2450                         $linkCache->forUpdate( $oldUpdate );
2451                 } else {
2452                         if ( -1 == $this->mArticleID ) {
2453                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2454                         }
2455                 }
2456                 return $this->mArticleID;
2457         }
2458
2459         /**
2460          * Is this an article that is a redirect page?
2461          * Uses link cache, adding it if necessary
2462          *
2463          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2464          * @return Bool
2465          */
2466         public function isRedirect( $flags = 0 ) {
2467                 if ( !is_null( $this->mRedirect ) ) {
2468                         return $this->mRedirect;
2469                 }
2470                 # Calling getArticleID() loads the field from cache as needed
2471                 if ( !$this->getArticleID( $flags ) ) {
2472                         return $this->mRedirect = false;
2473                 }
2474                 $linkCache = LinkCache::singleton();
2475                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2476
2477                 return $this->mRedirect;
2478         }
2479
2480         /**
2481          * What is the length of this page?
2482          * Uses link cache, adding it if necessary
2483          *
2484          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2485          * @return Int
2486          */
2487         public function getLength( $flags = 0 ) {
2488                 if ( $this->mLength != -1 ) {
2489                         return $this->mLength;
2490                 }
2491                 # Calling getArticleID() loads the field from cache as needed
2492                 if ( !$this->getArticleID( $flags ) ) {
2493                         return $this->mLength = 0;
2494                 }
2495                 $linkCache = LinkCache::singleton();
2496                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2497
2498                 return $this->mLength;
2499         }
2500
2501         /**
2502          * What is the page_latest field for this page?
2503          *
2504          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2505          * @return Int or 0 if the page doesn't exist
2506          */
2507         public function getLatestRevID( $flags = 0 ) {
2508                 if ( $this->mLatestID !== false ) {
2509                         return intval( $this->mLatestID );
2510                 }
2511                 # Calling getArticleID() loads the field from cache as needed
2512                 if ( !$this->getArticleID( $flags ) ) {
2513                         return $this->mLatestID = 0;
2514                 }
2515                 $linkCache = LinkCache::singleton();
2516                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2517
2518                 return $this->mLatestID;
2519         }
2520
2521         /**
2522          * This clears some fields in this object, and clears any associated
2523          * keys in the "bad links" section of the link cache.
2524          *
2525          * - This is called from Article::doEdit() and Article::insertOn() to allow
2526          * loading of the new page_id. It's also called from
2527          * Article::doDeleteArticle()
2528          *
2529          * @param $newid Int the new Article ID
2530          */
2531         public function resetArticleID( $newid ) {
2532                 $linkCache = LinkCache::singleton();
2533                 $linkCache->clearLink( $this );
2534
2535                 if ( $newid === false ) {
2536                         $this->mArticleID = -1;
2537                 } else {
2538                         $this->mArticleID = intval( $newid );
2539                 }
2540                 $this->mRestrictionsLoaded = false;
2541                 $this->mRestrictions = array();
2542                 $this->mRedirect = null;
2543                 $this->mLength = -1;
2544                 $this->mLatestID = false;
2545         }
2546
2547         /**
2548          * Updates page_touched for this page; called from LinksUpdate.php
2549          *
2550          * @return Bool true if the update succeded
2551          */
2552         public function invalidateCache() {
2553                 if ( wfReadOnly() ) {
2554                         return;
2555                 }
2556                 $dbw = wfGetDB( DB_MASTER );
2557                 $success = $dbw->update(
2558                         'page',
2559                         array( 'page_touched' => $dbw->timestamp() ),
2560                         $this->pageCond(),
2561                         __METHOD__
2562                 );
2563                 HTMLFileCache::clearFileCache( $this );
2564                 return $success;
2565         }
2566
2567         /**
2568          * Prefix some arbitrary text with the namespace or interwiki prefix
2569          * of this object
2570          *
2571          * @param $name String the text
2572          * @return String the prefixed text
2573          * @private
2574          */
2575         private function prefix( $name ) {
2576                 $p = '';
2577                 if ( $this->mInterwiki != '' ) {
2578                         $p = $this->mInterwiki . ':';
2579                 }
2580
2581                 if ( 0 != $this->mNamespace ) {
2582                         $p .= $this->getNsText() . ':';
2583                 }
2584                 return $p . $name;
2585         }
2586
2587         /**
2588          * Returns a simple regex that will match on characters and sequences invalid in titles.
2589          * Note that this doesn't pick up many things that could be wrong with titles, but that
2590          * replacing this regex with something valid will make many titles valid.
2591          *
2592          * @return String regex string
2593          */
2594         static function getTitleInvalidRegex() {
2595                 static $rxTc = false;
2596                 if ( !$rxTc ) {
2597                         # Matching titles will be held as illegal.
2598                         $rxTc = '/' .
2599                                 # Any character not allowed is forbidden...
2600                                 '[^' . Title::legalChars() . ']' .
2601                                 # URL percent encoding sequences interfere with the ability
2602                                 # to round-trip titles -- you can't link to them consistently.
2603                                 '|%[0-9A-Fa-f]{2}' .
2604                                 # XML/HTML character references produce similar issues.
2605                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2606                                 '|&#[0-9]+;' .
2607                                 '|&#x[0-9A-Fa-f]+;' .
2608                                 '/S';
2609                 }
2610
2611                 return $rxTc;
2612         }
2613
2614         /**
2615          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2616          *
2617          * @param $text String containing title to capitalize
2618          * @param $ns int namespace index, defaults to NS_MAIN
2619          * @return String containing capitalized title
2620          */
2621         public static function capitalize( $text, $ns = NS_MAIN ) {
2622                 global $wgContLang;
2623
2624                 if ( MWNamespace::isCapitalized( $ns ) ) {
2625                         return $wgContLang->ucfirst( $text );
2626                 } else {
2627                         return $text;
2628                 }
2629         }
2630
2631         /**
2632          * Secure and split - main initialisation function for this object
2633          *
2634          * Assumes that mDbkeyform has been set, and is urldecoded
2635          * and uses underscores, but not otherwise munged.  This function
2636          * removes illegal characters, splits off the interwiki and
2637          * namespace prefixes, sets the other forms, and canonicalizes
2638          * everything.
2639          *
2640          * @return Bool true on success
2641          */
2642         private function secureAndSplit() {
2643                 global $wgContLang, $wgLocalInterwiki;
2644
2645                 # Initialisation
2646                 $this->mInterwiki = $this->mFragment = '';
2647                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2648
2649                 $dbkey = $this->mDbkeyform;
2650
2651                 # Strip Unicode bidi override characters.
2652                 # Sometimes they slip into cut-n-pasted page titles, where the
2653                 # override chars get included in list displays.
2654                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2655
2656                 # Clean up whitespace
2657                 # Note: use of the /u option on preg_replace here will cause
2658                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2659                 # conveniently disabling them.
2660                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2661                 $dbkey = trim( $dbkey, '_' );
2662
2663                 if ( $dbkey == '' ) {
2664                         return false;
2665                 }
2666
2667                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2668                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2669                         return false;
2670                 }
2671
2672                 $this->mDbkeyform = $dbkey;
2673
2674                 # Initial colon indicates main namespace rather than specified default
2675                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2676                 if ( ':' == $dbkey[0] ) {
2677                         $this->mNamespace = NS_MAIN;
2678                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2679                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2680                 }
2681
2682                 # Namespace or interwiki prefix
2683                 $firstPass = true;
2684                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2685                 do {
2686                         $m = array();
2687                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2688                                 $p = $m[1];
2689                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2690                                         # Ordinary namespace
2691                                         $dbkey = $m[2];
2692                                         $this->mNamespace = $ns;
2693                                         # For Talk:X pages, check if X has a "namespace" prefix
2694                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2695                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2696                                                         # Disallow Talk:File:x type titles...
2697                                                         return false;
2698                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2699                                                         # Disallow Talk:Interwiki:x type titles...
2700                                                         return false;
2701                                                 }
2702                                         }
2703                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2704                                         if ( !$firstPass ) {
2705                                                 # Can't make a local interwiki link to an interwiki link.
2706                                                 # That's just crazy!
2707                                                 return false;
2708                                         }
2709
2710                                         # Interwiki link
2711                                         $dbkey = $m[2];
2712                                         $this->mInterwiki = $wgContLang->lc( $p );
2713
2714                                         # Redundant interwiki prefix to the local wiki
2715                                         if ( $wgLocalInterwiki !== false
2716                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2717                                         {
2718                                                 if ( $dbkey == '' ) {
2719                                                         # Can't have an empty self-link
2720                                                         return false;
2721                                                 }
2722                                                 $this->mInterwiki = '';
2723                                                 $firstPass = false;
2724                                                 # Do another namespace split...
2725                                                 continue;
2726                                         }
2727
2728                                         # If there's an initial colon after the interwiki, that also
2729                                         # resets the default namespace
2730                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2731                                                 $this->mNamespace = NS_MAIN;
2732                                                 $dbkey = substr( $dbkey, 1 );
2733                                         }
2734                                 }
2735                                 # If there's no recognized interwiki or namespace,
2736                                 # then let the colon expression be part of the title.
2737                         }
2738                         break;
2739                 } while ( true );
2740
2741                 # We already know that some pages won't be in the database!
2742                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2743                         $this->mArticleID = 0;
2744                 }
2745                 $fragment = strstr( $dbkey, '#' );
2746                 if ( false !== $fragment ) {
2747                         $this->setFragment( $fragment );
2748                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2749                         # remove whitespace again: prevents "Foo_bar_#"
2750                         # becoming "Foo_bar_"
2751                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2752                 }
2753
2754                 # Reject illegal characters.
2755                 $rxTc = self::getTitleInvalidRegex();
2756                 if ( preg_match( $rxTc, $dbkey ) ) {
2757                         return false;
2758                 }
2759
2760                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2761                 # reachable due to the way web browsers deal with 'relative' URLs.
2762                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2763                 if ( strpos( $dbkey, '.' ) !== false &&
2764                          ( $dbkey === '.' || $dbkey === '..' ||
2765                            strpos( $dbkey, './' ) === 0  ||
2766                            strpos( $dbkey, '../' ) === 0 ||
2767                            strpos( $dbkey, '/./' ) !== false ||
2768                            strpos( $dbkey, '/../' ) !== false  ||
2769                            substr( $dbkey, -2 ) == '/.' ||
2770                            substr( $dbkey, -3 ) == '/..' ) )
2771                 {
2772                         return false;
2773                 }
2774
2775                 # Magic tilde sequences? Nu-uh!
2776                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2777                         return false;
2778                 }
2779
2780                 # Limit the size of titles to 255 bytes. This is typically the size of the
2781                 # underlying database field. We make an exception for special pages, which
2782                 # don't need to be stored in the database, and may edge over 255 bytes due
2783                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2784                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2785                   strlen( $dbkey ) > 512 )
2786                 {
2787                         return false;
2788                 }
2789
2790                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2791                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2792                 # other site might be case-sensitive.
2793                 $this->mUserCaseDBKey = $dbkey;
2794                 if ( $this->mInterwiki == '' ) {
2795                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2796                 }
2797
2798                 # Can't make a link to a namespace alone... "empty" local links can only be
2799                 # self-links with a fragment identifier.
2800                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2801                         return false;
2802                 }
2803
2804                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2805                 // IP names are not allowed for accounts, and can only be referring to
2806                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2807                 // there are numerous ways to present the same IP. Having sp:contribs scan
2808                 // them all is silly and having some show the edits and others not is
2809                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2810                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2811                         ? IP::sanitizeIP( $dbkey )
2812                         : $dbkey;
2813
2814                 // Any remaining initial :s are illegal.
2815                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
2816                         return false;
2817                 }
2818
2819                 # Fill fields
2820                 $this->mDbkeyform = $dbkey;
2821                 $this->mUrlform = wfUrlencode( $dbkey );
2822
2823                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2824
2825                 return true;
2826         }
2827
2828         /**
2829          * Set the fragment for this title. Removes the first character from the
2830          * specified fragment before setting, so it assumes you're passing it with
2831          * an initial "#".
2832          *
2833          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2834          * Still in active use privately.
2835          *
2836          * @param $fragment String text
2837          */
2838         public function setFragment( $fragment ) {
2839                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2840         }
2841
2842         /**
2843          * Get a Title object associated with the talk page of this article
2844          *
2845          * @return Title the object for the talk page
2846          */
2847         public function getTalkPage() {
2848                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2849         }
2850
2851         /**
2852          * Get a title object associated with the subject page of this
2853          * talk page
2854          *
2855          * @return Title the object for the subject page
2856          */
2857         public function getSubjectPage() {
2858                 // Is this the same title?
2859                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2860                 if ( $this->getNamespace() == $subjectNS ) {
2861                         return $this;
2862                 }
2863                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2864         }
2865
2866         /**
2867          * Get an array of Title objects linking to this Title
2868          * Also stores the IDs in the link cache.
2869          *
2870          * WARNING: do not use this function on arbitrary user-supplied titles!
2871          * On heavily-used templates it will max out the memory.
2872          *
2873          * @param $options Array: may be FOR UPDATE
2874          * @param $table String: table name
2875          * @param $prefix String: fields prefix
2876          * @return Array of Title objects linking here
2877          */
2878         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2879                 $linkCache = LinkCache::singleton();
2880
2881                 if ( count( $options ) > 0 ) {
2882                         $db = wfGetDB( DB_MASTER );
2883                 } else {
2884                         $db = wfGetDB( DB_SLAVE );
2885                 }
2886
2887                 $res = $db->select(
2888                         array( 'page', $table ),
2889                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2890                         array(
2891                                 "{$prefix}_from=page_id",
2892                                 "{$prefix}_namespace" => $this->getNamespace(),
2893                                 "{$prefix}_title"     => $this->getDBkey() ),
2894                         __METHOD__,
2895                         $options
2896                 );
2897
2898                 $retVal = array();
2899                 if ( $db->numRows( $res ) ) {
2900                         foreach ( $res as $row ) {
2901                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2902                                 if ( $titleObj ) {
2903                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
2904                                         $retVal[] = $titleObj;
2905                                 }
2906                         }
2907                 }
2908                 return $retVal;
2909         }
2910
2911         /**
2912          * Get an array of Title objects using this Title as a template
2913          * Also stores the IDs in the link cache.
2914          *
2915          * WARNING: do not use this function on arbitrary user-supplied titles!
2916          * On heavily-used templates it will max out the memory.
2917          *
2918          * @param $options Array: may be FOR UPDATE
2919          * @return Array of Title the Title objects linking here
2920          */
2921         public function getTemplateLinksTo( $options = array() ) {
2922                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2923         }
2924
2925         /**
2926          * Get an array of Title objects referring to non-existent articles linked from this page
2927          *
2928          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2929          * @return Array of Title the Title objects
2930          */
2931         public function getBrokenLinksFrom() {
2932                 if ( $this->getArticleId() == 0 ) {
2933                         # All links from article ID 0 are false positives
2934                         return array();
2935                 }
2936
2937                 $dbr = wfGetDB( DB_SLAVE );
2938                 $res = $dbr->select(
2939                         array( 'page', 'pagelinks' ),
2940                         array( 'pl_namespace', 'pl_title' ),
2941                         array(
2942                                 'pl_from' => $this->getArticleId(),
2943                                 'page_namespace IS NULL'
2944                         ),
2945                         __METHOD__, array(),
2946                         array(
2947                                 'page' => array(
2948                                         'LEFT JOIN',
2949                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2950                                 )
2951                         )
2952                 );
2953
2954                 $retVal = array();
2955                 foreach ( $res as $row ) {
2956                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2957                 }
2958                 return $retVal;
2959         }
2960
2961
2962         /**
2963          * Get a list of URLs to purge from the Squid cache when this
2964          * page changes
2965          *
2966          * @return Array of String the URLs
2967          */
2968         public function getSquidURLs() {
2969                 global $wgContLang;
2970
2971                 $urls = array(
2972                         $this->getInternalURL(),
2973                         $this->getInternalURL( 'action=history' )
2974                 );
2975
2976                 // purge variant urls as well
2977                 if ( $wgContLang->hasVariants() ) {
2978                         $variants = $wgContLang->getVariants();
2979                         foreach ( $variants as $vCode ) {
2980                                 $urls[] = $this->getInternalURL( '', $vCode );
2981                         }
2982                 }
2983
2984                 return $urls;
2985         }
2986
2987         /**
2988          * Purge all applicable Squid URLs
2989          */
2990         public function purgeSquid() {
2991                 global $wgUseSquid;
2992                 if ( $wgUseSquid ) {
2993                         $urls = $this->getSquidURLs();
2994                         $u = new SquidUpdate( $urls );
2995                         $u->doUpdate();
2996                 }
2997         }
2998
2999         /**
3000          * Move this page without authentication
3001          *
3002          * @param $nt Title the new page Title
3003          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3004          */
3005         public function moveNoAuth( &$nt ) {
3006                 return $this->moveTo( $nt, false );
3007         }
3008
3009         /**
3010          * Check whether a given move operation would be valid.
3011          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3012          *
3013          * @param $nt Title the new title
3014          * @param $auth Bool indicates whether $wgUser's permissions
3015          *  should be checked
3016          * @param $reason String is the log summary of the move, used for spam checking
3017          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3018          */
3019         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3020                 global $wgUser;
3021
3022                 $errors = array();
3023                 if ( !$nt ) {
3024                         // Normally we'd add this to $errors, but we'll get
3025                         // lots of syntax errors if $nt is not an object
3026                         return array( array( 'badtitletext' ) );
3027                 }
3028                 if ( $this->equals( $nt ) ) {
3029                         $errors[] = array( 'selfmove' );
3030                 }
3031                 if ( !$this->isMovable() ) {
3032                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3033                 }
3034                 if ( $nt->getInterwiki() != '' ) {
3035                         $errors[] = array( 'immobile-target-namespace-iw' );
3036                 }
3037                 if ( !$nt->isMovable() ) {
3038                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3039                 }
3040
3041                 $oldid = $this->getArticleID();
3042                 $newid = $nt->getArticleID();
3043
3044                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3045                         $errors[] = array( 'articleexists' );
3046                 }
3047                 if ( ( $this->getDBkey() == '' ) ||
3048                          ( !$oldid ) ||
3049                          ( $nt->getDBkey() == '' ) ) {
3050                         $errors[] = array( 'badarticleerror' );
3051                 }
3052
3053                 // Image-specific checks
3054                 if ( $this->getNamespace() == NS_FILE ) {
3055                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3056                 }
3057
3058                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3059                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3060                 }
3061
3062                 if ( $auth ) {
3063                         $errors = wfMergeErrorArrays( $errors,
3064                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3065                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3066                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3067                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3068                 }
3069
3070                 $match = EditPage::matchSummarySpamRegex( $reason );
3071                 if ( $match !== false ) {
3072                         // This is kind of lame, won't display nice
3073                         $errors[] = array( 'spamprotectiontext' );
3074                 }
3075
3076                 $err = null;
3077                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3078                         $errors[] = array( 'hookaborted', $err );
3079                 }
3080
3081                 # The move is allowed only if (1) the target doesn't exist, or
3082                 # (2) the target is a redirect to the source, and has no history
3083                 # (so we can undo bad moves right after they're done).
3084
3085                 if ( 0 != $newid ) { # Target exists; check for validity
3086                         if ( !$this->isValidMoveTarget( $nt ) ) {
3087                                 $errors[] = array( 'articleexists' );
3088                         }
3089                 } else {
3090                         $tp = $nt->getTitleProtection();
3091                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3092                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3093                                 $errors[] = array( 'cantmove-titleprotected' );
3094                         }
3095                 }
3096                 if ( empty( $errors ) ) {
3097                         return true;
3098                 }
3099                 return $errors;
3100         }
3101
3102         /**
3103          * Check if the requested move target is a valid file move target
3104          * @param Title $nt Target title
3105          * @return array List of errors
3106          */
3107         protected function validateFileMoveOperation( $nt ) {
3108                 global $wgUser;
3109
3110                 $errors = array();
3111
3112                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3113
3114                 $file = wfLocalFile( $this );
3115                 if ( $file->exists() ) {
3116                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3117                                 $errors[] = array( 'imageinvalidfilename' );
3118                         }
3119                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3120                                 $errors[] = array( 'imagetypemismatch' );
3121                         }
3122                 }
3123
3124                 if ( $nt->getNamespace() != NS_FILE ) {
3125                         $errors[] = array( 'imagenocrossnamespace' );
3126                         // From here we want to do checks on a file object, so if we can't
3127                         // create one, we must return.
3128                         return $errors;
3129                 }
3130
3131                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3132
3133                 $destFile = wfLocalFile( $nt );
3134                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3135                         $errors[] = array( 'file-exists-sharedrepo' );
3136                 }
3137
3138                 return $errors;
3139         }
3140
3141         /**
3142          * Move a title to a new location
3143          *
3144          * @param $nt Title the new title
3145          * @param $auth Bool indicates whether $wgUser's permissions
3146          *  should be checked
3147          * @param $reason String the reason for the move
3148          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3149          *  Ignored if the user doesn't have the suppressredirect right.
3150          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3151          */
3152         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3153                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3154                 if ( is_array( $err ) ) {
3155                         return $err;
3156                 }
3157
3158                 // If it is a file, move it first.
3159                 // It is done before all other moving stuff is done because it's hard to revert.
3160                 $dbw = wfGetDB( DB_MASTER );
3161                 if ( $this->getNamespace() == NS_FILE ) {
3162                         $file = wfLocalFile( $this );
3163                         if ( $file->exists() ) {
3164                                 $status = $file->move( $nt );
3165                                 if ( !$status->isOk() ) {
3166                                         return $status->getErrorsArray();
3167                                 }
3168                         }
3169                 }
3170                 // Clear RepoGroup process cache
3171                 RepoGroup::singleton()->clearCache( $this );
3172                 RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3173
3174                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3175                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3176                 $protected = $this->isProtected();
3177                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3178
3179                 // Do the actual move
3180                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3181                 if ( is_array( $err ) ) {
3182                         # @todo FIXME: What about the File we have already moved?
3183                         $dbw->rollback();
3184                         return $err;
3185                 }
3186
3187                 $redirid = $this->getArticleID();
3188
3189                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3190                 // cl_timestamp, which may disturb time-based lists on some sites.
3191                 $prefixes = $dbw->select(
3192                         'categorylinks',
3193                         array( 'cl_sortkey_prefix', 'cl_to' ),
3194                         array( 'cl_from' => $pageid ),
3195                         __METHOD__
3196                 );
3197                 foreach ( $prefixes as $prefixRow ) {
3198                         $prefix = $prefixRow->cl_sortkey_prefix;
3199                         $catTo = $prefixRow->cl_to;
3200                         $dbw->update( 'categorylinks',
3201                                 array(
3202                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3203                                                 $nt->getCategorySortkey( $prefix ) ),
3204                                         'cl_timestamp=cl_timestamp' ),
3205                                 array(
3206                                         'cl_from' => $pageid,
3207                                         'cl_to' => $catTo ),
3208                                 __METHOD__
3209                         );
3210                 }
3211
3212                 if ( $protected ) {
3213                         # Protect the redirect title as the title used to be...
3214                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3215                                 array(
3216                                         'pr_page'    => $redirid,
3217                                         'pr_type'    => 'pr_type',
3218                                         'pr_level'   => 'pr_level',
3219                                         'pr_cascade' => 'pr_cascade',
3220                                         'pr_user'    => 'pr_user',
3221                                         'pr_expiry'  => 'pr_expiry'
3222                                 ),
3223                                 array( 'pr_page' => $pageid ),
3224                                 __METHOD__,
3225                                 array( 'IGNORE' )
3226                         );
3227                         # Update the protection log
3228                         $log = new LogPage( 'protect' );
3229                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3230                         if ( $reason ) {
3231                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3232                         }
3233                         // @todo FIXME: $params?
3234                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3235                 }
3236
3237                 # Update watchlists
3238                 $oldnamespace = $this->getNamespace() & ~1;
3239                 $newnamespace = $nt->getNamespace() & ~1;
3240                 $oldtitle = $this->getDBkey();
3241                 $newtitle = $nt->getDBkey();
3242
3243                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3244                         WatchedItem::duplicateEntries( $this, $nt );
3245                 }
3246
3247                 # Update search engine
3248                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3249                 $u->doUpdate();
3250                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3251                 $u->doUpdate();
3252
3253                 $dbw->commit();
3254
3255                 # Update site_stats
3256                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3257                         # No longer a content page
3258                         # Not viewed, edited, removing
3259                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3260                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3261                         # Now a content page
3262                         # Not viewed, edited, adding
3263                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3264                 } elseif ( $pageCountChange ) {
3265                         # Redirect added
3266                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3267                 } else {
3268                         # Nothing special
3269                         $u = false;
3270                 }
3271                 if ( $u ) {
3272                         $u->doUpdate();
3273                 }
3274
3275                 # Update message cache for interface messages
3276                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3277                         # @bug 17860: old article can be deleted, if this the case,
3278                         # delete it from message cache
3279                         if ( $this->getArticleID() === 0 ) {
3280                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3281                         } else {
3282                                 $oldarticle = new Article( $this );
3283                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3284                         }
3285                 }
3286                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3287                         $newarticle = new Article( $nt );
3288                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3289                 }
3290
3291                 global $wgUser;
3292                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3293                 return true;
3294         }
3295
3296         /**
3297          * Move page to a title which is either a redirect to the
3298          * source page or nonexistent
3299          *
3300          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3301          * @param $reason String The reason for the move
3302          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3303          *   if the user doesn't have the suppressredirect right
3304          */
3305         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3306                 global $wgUser, $wgContLang;
3307
3308                 if ( $nt->exists() ) {
3309                         $moveOverRedirect = true;
3310                         $logType = 'move_redir';
3311                 } else {
3312                         $moveOverRedirect = false;
3313                         $logType = 'move';
3314                 }
3315
3316                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3317
3318                 $logEntry = new ManualLogEntry( 'move', $logType );
3319                 $logEntry->setPerformer( $wgUser );
3320                 $logEntry->setTarget( $this );
3321                 $logEntry->setComment( $reason );
3322                 $logEntry->setParameters( array(
3323                         '4::target' => $nt->getPrefixedText(),
3324                         '5::noredir' => $redirectSuppressed ? '1': '0',
3325                 ) );
3326
3327                 $formatter = LogFormatter::newFromEntry( $logEntry );
3328                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3329                 $comment = $formatter->getPlainActionText();
3330                 if ( $reason ) {
3331                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3332                 }
3333                 # Truncate for whole multibyte characters.
3334                 $comment = $wgContLang->truncate( $comment, 255 );
3335
3336                 $oldid = $this->getArticleID();
3337                 $latest = $this->getLatestRevID();
3338
3339                 $dbw = wfGetDB( DB_MASTER );
3340
3341                 if ( $moveOverRedirect ) {
3342                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3343
3344                         $newid = $nt->getArticleID();
3345                         $newns = $nt->getNamespace();
3346                         $newdbk = $nt->getDBkey();
3347
3348                         # Delete the old redirect. We don't save it to history since
3349                         # by definition if we've got here it's rather uninteresting.
3350                         # We have to remove it so that the next step doesn't trigger
3351                         # a conflict on the unique namespace+title index...
3352                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3353                         if ( !$dbw->cascadingDeletes() ) {
3354                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3355                                 global $wgUseTrackbacks;
3356                                 if ( $wgUseTrackbacks ) {
3357                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3358                                 }
3359                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3360                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3361                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3362                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3363                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3364                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3365                                 $dbw->delete( 'iwlinks', array( 'iwl_from' => $newid ), __METHOD__ );
3366                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3367                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3368                         }
3369                         // If the target page was recently created, it may have an entry in recentchanges still
3370                         $dbw->delete( 'recentchanges',
3371                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3372                                 __METHOD__
3373                         );
3374                 }
3375
3376                 # Save a null revision in the page's history notifying of the move
3377                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3378                 if ( !is_object( $nullRevision ) ) {
3379                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3380                 }
3381                 $nullRevId = $nullRevision->insertOn( $dbw );
3382
3383                 $now = wfTimestampNow();
3384                 # Change the name of the target page:
3385                 $dbw->update( 'page',
3386                         /* SET */ array(
3387                                 'page_touched'   => $dbw->timestamp( $now ),
3388                                 'page_namespace' => $nt->getNamespace(),
3389                                 'page_title'     => $nt->getDBkey(),
3390                                 'page_latest'    => $nullRevId,
3391                         ),
3392                         /* WHERE */ array( 'page_id' => $oldid ),
3393                         __METHOD__
3394                 );
3395                 $nt->resetArticleID( $oldid );
3396
3397                 $article = new Article( $nt );
3398                 wfRunHooks( 'NewRevisionFromEditComplete',
3399                         array( $article, $nullRevision, $latest, $wgUser ) );
3400                 $article->setCachedLastEditTime( $now );
3401
3402                 # Recreate the redirect, this time in the other direction.
3403                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3404                         $mwRedir = MagicWord::get( 'redirect' );
3405                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3406                         $redirectArticle = new Article( $this );
3407                         $newid = $redirectArticle->insertOn( $dbw );
3408                         if ( $newid ) { // sanity
3409                                 $redirectRevision = new Revision( array(
3410                                         'page'    => $newid,
3411                                         'comment' => $comment,
3412                                         'text'    => $redirectText ) );
3413                                 $redirectRevision->insertOn( $dbw );
3414                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3415
3416                                 wfRunHooks( 'NewRevisionFromEditComplete',
3417                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3418
3419                                 # Now, we record the link from the redirect to the new title.
3420                                 # It should have no other outgoing links...
3421                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3422                                 $dbw->insert( 'pagelinks',
3423                                         array(
3424                                                 'pl_from'      => $newid,
3425                                                 'pl_namespace' => $nt->getNamespace(),
3426                                                 'pl_title'     => $nt->getDBkey() ),
3427                                         __METHOD__ );
3428                         }
3429                 } else {
3430                         $this->resetArticleID( 0 );
3431                 }
3432
3433                 # Log the move
3434                 $logid = $logEntry->insert();
3435                 $logEntry->publish( $logid );
3436
3437                 # Purge caches for old and new titles
3438                 if ( $moveOverRedirect ) {
3439                         # A simple purge is enough when moving over a redirect
3440                         $nt->purgeSquid();
3441                 } else {
3442                         # Purge caches as per article creation, including any pages that link to this title
3443                         Article::onArticleCreate( $nt );
3444                 }
3445                 $this->purgeSquid();
3446         }
3447
3448         /**
3449          * Move this page's subpages to be subpages of $nt
3450          *
3451          * @param $nt Title Move target
3452          * @param $auth bool Whether $wgUser's permissions should be checked
3453          * @param $reason string The reason for the move
3454          * @param $createRedirect bool Whether to create redirects from the old subpages to
3455          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3456          * @return mixed array with old page titles as keys, and strings (new page titles) or
3457          *     arrays (errors) as values, or an error array with numeric indices if no pages
3458          *     were moved
3459          */
3460         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3461                 global $wgMaximumMovedPages;
3462                 // Check permissions
3463                 if ( !$this->userCan( 'move-subpages' ) ) {
3464                         return array( 'cant-move-subpages' );
3465                 }
3466                 // Do the source and target namespaces support subpages?
3467                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3468                         return array( 'namespace-nosubpages',
3469                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3470                 }
3471                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3472                         return array( 'namespace-nosubpages',
3473                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3474                 }
3475
3476                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3477                 $retval = array();
3478                 $count = 0;
3479                 foreach ( $subpages as $oldSubpage ) {
3480                         $count++;
3481                         if ( $count > $wgMaximumMovedPages ) {
3482                                 $retval[$oldSubpage->getPrefixedTitle()] =
3483                                                 array( 'movepage-max-pages',
3484                                                         $wgMaximumMovedPages );
3485                                 break;
3486                         }
3487
3488                         // We don't know whether this function was called before
3489                         // or after moving the root page, so check both
3490                         // $this and $nt
3491                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3492                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3493                         {
3494                                 // When moving a page to a subpage of itself,
3495                                 // don't move it twice
3496                                 continue;
3497                         }
3498                         $newPageName = preg_replace(
3499                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3500                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3501                                         $oldSubpage->getDBkey() );
3502                         if ( $oldSubpage->isTalkPage() ) {
3503                                 $newNs = $nt->getTalkPage()->getNamespace();
3504                         } else {
3505                                 $newNs = $nt->getSubjectPage()->getNamespace();
3506                         }
3507                         # Bug 14385: we need makeTitleSafe because the new page names may
3508                         # be longer than 255 characters.
3509                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3510
3511                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3512                         if ( $success === true ) {
3513                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3514                         } else {
3515                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3516                         }
3517                 }
3518                 return $retval;
3519         }
3520
3521         /**
3522          * Checks if this page is just a one-rev redirect.
3523          * Adds lock, so don't use just for light purposes.
3524          *
3525          * @return Bool
3526          */
3527         public function isSingleRevRedirect() {
3528                 $dbw = wfGetDB( DB_MASTER );
3529                 # Is it a redirect?
3530                 $row = $dbw->selectRow( 'page',
3531                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3532                         $this->pageCond(),
3533                         __METHOD__,
3534                         array( 'FOR UPDATE' )
3535                 );
3536                 # Cache some fields we may want
3537                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3538                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3539                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3540                 if ( !$this->mRedirect ) {
3541                         return false;
3542                 }
3543                 # Does the article have a history?
3544                 $row = $dbw->selectField( array( 'page', 'revision' ),
3545                         'rev_id',
3546                         array( 'page_namespace' => $this->getNamespace(),
3547                                 'page_title' => $this->getDBkey(),
3548                                 'page_id=rev_page',
3549                                 'page_latest != rev_id'
3550                         ),
3551                         __METHOD__,
3552                         array( 'FOR UPDATE' )
3553                 );
3554                 # Return true if there was no history
3555                 return ( $row === false );
3556         }
3557
3558         /**
3559          * Checks if $this can be moved to a given Title
3560          * - Selects for update, so don't call it unless you mean business
3561          *
3562          * @param $nt Title the new title to check
3563          * @return Bool
3564          */
3565         public function isValidMoveTarget( $nt ) {
3566                 # Is it an existing file?
3567                 if ( $nt->getNamespace() == NS_FILE ) {
3568                         $file = wfLocalFile( $nt );
3569                         if ( $file->exists() ) {
3570                                 wfDebug( __METHOD__ . ": file exists\n" );
3571                                 return false;
3572                         }
3573                 }
3574                 # Is it a redirect with no history?
3575                 if ( !$nt->isSingleRevRedirect() ) {
3576                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3577                         return false;
3578                 }
3579                 # Get the article text
3580                 $rev = Revision::newFromTitle( $nt );
3581                 if( !is_object( $rev ) ){
3582                         return false;
3583                 }
3584                 $text = $rev->getText();
3585                 # Does the redirect point to the source?
3586                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3587                 $m = array();
3588                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3589                         $redirTitle = Title::newFromText( $m[1] );
3590                         if ( !is_object( $redirTitle ) ||
3591                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3592                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3593                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3594                                 return false;
3595                         }
3596                 } else {
3597                         # Fail safe
3598                         wfDebug( __METHOD__ . ": failsafe\n" );
3599                         return false;
3600                 }
3601                 return true;
3602         }
3603
3604         /**
3605          * Can this title be added to a user's watchlist?
3606          *
3607          * @return Bool TRUE or FALSE
3608          */
3609         public function isWatchable() {
3610                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3611         }
3612
3613         /**
3614          * Get categories to which this Title belongs and return an array of
3615          * categories' names.
3616          *
3617          * @return Array of parents in the form:
3618          *        $parent => $currentarticle
3619          */
3620         public function getParentCategories() {
3621                 global $wgContLang;
3622
3623                 $data = array();
3624
3625                 $titleKey = $this->getArticleId();
3626
3627                 if ( $titleKey === 0 ) {
3628                         return $data;
3629                 }
3630
3631                 $dbr = wfGetDB( DB_SLAVE );
3632
3633                 $res = $dbr->select( 'categorylinks', '*',
3634                         array(
3635                                 'cl_from' => $titleKey,
3636                         ),
3637                         __METHOD__,
3638                         array()
3639                 );
3640
3641                 if ( $dbr->numRows( $res ) > 0 ) {
3642                         foreach ( $res as $row ) {
3643                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3644                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3645                         }
3646                 }
3647                 return $data;
3648         }
3649
3650         /**
3651          * Get a tree of parent categories
3652          *
3653          * @param $children Array with the children in the keys, to check for circular refs
3654          * @return Array Tree of parent categories
3655          */
3656         public function getParentCategoryTree( $children = array() ) {
3657                 $stack = array();
3658                 $parents = $this->getParentCategories();
3659
3660                 if ( $parents ) {
3661                         foreach ( $parents as $parent => $current ) {
3662                                 if ( array_key_exists( $parent, $children ) ) {
3663                                         # Circular reference
3664                                         $stack[$parent] = array();
3665                                 } else {
3666                                         $nt = Title::newFromText( $parent );
3667                                         if ( $nt ) {
3668                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3669                                         }
3670                                 }
3671                         }
3672                 }
3673
3674                 return $stack;
3675         }
3676
3677         /**
3678          * Get an associative array for selecting this title from
3679          * the "page" table
3680          *
3681          * @return Array suitable for the $where parameter of DB::select()
3682          */
3683         public function pageCond() {
3684                 if ( $this->mArticleID > 0 ) {
3685                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3686                         return array( 'page_id' => $this->mArticleID );
3687                 } else {
3688                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3689                 }
3690         }
3691
3692         /**
3693          * Get the revision ID of the previous revision
3694          *
3695          * @param $revId Int Revision ID. Get the revision that was before this one.
3696          * @param $flags Int Title::GAID_FOR_UPDATE
3697          * @return Int|Bool Old revision ID, or FALSE if none exists
3698          */
3699         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3700                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3701                 return $db->selectField( 'revision', 'rev_id',
3702                         array(
3703                                 'rev_page' => $this->getArticleId( $flags ),
3704                                 'rev_id < ' . intval( $revId )
3705                         ),
3706                         __METHOD__,
3707                         array( 'ORDER BY' => 'rev_id DESC' )
3708                 );
3709         }
3710
3711         /**
3712          * Get the revision ID of the next revision
3713          *
3714          * @param $revId Int Revision ID. Get the revision that was after this one.
3715          * @param $flags Int Title::GAID_FOR_UPDATE
3716          * @return Int|Bool Next revision ID, or FALSE if none exists
3717          */
3718         public function getNextRevisionID( $revId, $flags = 0 ) {
3719                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3720                 return $db->selectField( 'revision', 'rev_id',
3721                         array(
3722                                 'rev_page' => $this->getArticleId( $flags ),
3723                                 'rev_id > ' . intval( $revId )
3724                         ),
3725                         __METHOD__,
3726                         array( 'ORDER BY' => 'rev_id' )
3727                 );
3728         }
3729
3730         /**
3731          * Get the first revision of the page
3732          *
3733          * @param $flags Int Title::GAID_FOR_UPDATE
3734          * @return Revision|Null if page doesn't exist
3735          */
3736         public function getFirstRevision( $flags = 0 ) {
3737                 $pageId = $this->getArticleId( $flags );
3738                 if ( $pageId ) {
3739                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3740                         $row = $db->selectRow( 'revision', '*',
3741                                 array( 'rev_page' => $pageId ),
3742                                 __METHOD__,
3743                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3744                         );
3745                         if ( $row ) {
3746                                 return new Revision( $row );
3747                         }
3748                 }
3749                 return null;
3750         }
3751
3752         /**
3753          * Get the oldest revision timestamp of this page
3754          *
3755          * @param $flags Int Title::GAID_FOR_UPDATE
3756          * @return String: MW timestamp
3757          */
3758         public function getEarliestRevTime( $flags = 0 ) {
3759                 $rev = $this->getFirstRevision( $flags );
3760                 return $rev ? $rev->getTimestamp() : null;
3761         }
3762
3763         /**
3764          * Check if this is a new page
3765          *
3766          * @return bool
3767          */
3768         public function isNewPage() {
3769                 $dbr = wfGetDB( DB_SLAVE );
3770                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3771         }
3772
3773         /**
3774          * Get the number of revisions between the given revision.
3775          * Used for diffs and other things that really need it.
3776          *
3777          * @param $old int|Revision Old revision or rev ID (first before range)
3778          * @param $new int|Revision New revision or rev ID (first after range)
3779          * @return Int Number of revisions between these revisions.
3780          */
3781         public function countRevisionsBetween( $old, $new ) {
3782                 if ( !( $old instanceof Revision ) ) {
3783                         $old = Revision::newFromTitle( $this, (int)$old );
3784                 }
3785                 if ( !( $new instanceof Revision ) ) {
3786                         $new = Revision::newFromTitle( $this, (int)$new );
3787                 }
3788                 if ( !$old || !$new ) {
3789                         return 0; // nothing to compare
3790                 }
3791                 $dbr = wfGetDB( DB_SLAVE );
3792                 return (int)$dbr->selectField( 'revision', 'count(*)',
3793                         array(
3794                                 'rev_page' => $this->getArticleId(),
3795                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3796                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3797                         ),
3798                         __METHOD__
3799                 );
3800         }
3801
3802         /**
3803          * Get the number of authors between the given revision IDs.
3804          * Used for diffs and other things that really need it.
3805          *
3806          * @param $old int|Revision Old revision or rev ID (first before range)
3807          * @param $new int|Revision New revision or rev ID (first after range)
3808          * @param $limit Int Maximum number of authors
3809          * @return Int Number of revision authors between these revisions.
3810          */
3811         public function countAuthorsBetween( $old, $new, $limit ) {
3812                 if ( !( $old instanceof Revision ) ) {
3813                         $old = Revision::newFromTitle( $this, (int)$old );
3814                 }
3815                 if ( !( $new instanceof Revision ) ) {
3816                         $new = Revision::newFromTitle( $this, (int)$new );
3817                 }
3818                 if ( !$old || !$new ) {
3819                         return 0; // nothing to compare
3820                 }
3821                 $dbr = wfGetDB( DB_SLAVE );
3822                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3823                         array(
3824                                 'rev_page' => $this->getArticleID(),
3825                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3826                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3827                         ), __METHOD__,
3828                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3829                 );
3830                 return (int)$dbr->numRows( $res );
3831         }
3832
3833         /**
3834          * Compare with another title.
3835          *
3836          * @param $title Title
3837          * @return Bool
3838          */
3839         public function equals( Title $title ) {
3840                 // Note: === is necessary for proper matching of number-like titles.
3841                 return $this->getInterwiki() === $title->getInterwiki()
3842                         && $this->getNamespace() == $title->getNamespace()
3843                         && $this->getDBkey() === $title->getDBkey();
3844         }
3845
3846         /**
3847          * Check if this title is a subpage of another title
3848          *
3849          * @param $title Title
3850          * @return Bool
3851          */
3852         public function isSubpageOf( Title $title ) {
3853                 return $this->getInterwiki() === $title->getInterwiki()
3854                         && $this->getNamespace() == $title->getNamespace()
3855                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
3856         }
3857
3858         /**
3859          * Callback for usort() to do title sorts by (namespace, title)
3860          *
3861          * @param $a Title
3862          * @param $b Title
3863          *
3864          * @return Integer: result of string comparison, or namespace comparison
3865          */
3866         public static function compare( $a, $b ) {
3867                 if ( $a->getNamespace() == $b->getNamespace() ) {
3868                         return strcmp( $a->getText(), $b->getText() );
3869                 } else {
3870                         return $a->getNamespace() - $b->getNamespace();
3871                 }
3872         }
3873
3874         /**
3875          * Return a string representation of this title
3876          *
3877          * @return String representation of this title
3878          */
3879         public function __toString() {
3880                 return $this->getPrefixedText();
3881         }
3882
3883         /**
3884          * Check if page exists.  For historical reasons, this function simply
3885          * checks for the existence of the title in the page table, and will
3886          * thus return false for interwiki links, special pages and the like.
3887          * If you want to know if a title can be meaningfully viewed, you should
3888          * probably call the isKnown() method instead.
3889          *
3890          * @return Bool
3891          */
3892         public function exists() {
3893                 return $this->getArticleId() != 0;
3894         }
3895
3896         /**
3897          * Should links to this title be shown as potentially viewable (i.e. as
3898          * "bluelinks"), even if there's no record by this title in the page
3899          * table?
3900          *
3901          * This function is semi-deprecated for public use, as well as somewhat
3902          * misleadingly named.  You probably just want to call isKnown(), which
3903          * calls this function internally.
3904          *
3905          * (ISSUE: Most of these checks are cheap, but the file existence check
3906          * can potentially be quite expensive.  Including it here fixes a lot of
3907          * existing code, but we might want to add an optional parameter to skip
3908          * it and any other expensive checks.)
3909          *
3910          * @return Bool
3911          */
3912         public function isAlwaysKnown() {
3913                 if ( $this->mInterwiki != '' ) {
3914                         return true;  // any interwiki link might be viewable, for all we know
3915                 }
3916                 switch( $this->mNamespace ) {
3917                         case NS_MEDIA:
3918                         case NS_FILE:
3919                                 // file exists, possibly in a foreign repo
3920                                 return (bool)wfFindFile( $this );
3921                         case NS_SPECIAL:
3922                                 // valid special page
3923                                 return SpecialPageFactory::exists( $this->getDBkey() );
3924                         case NS_MAIN:
3925                                 // selflink, possibly with fragment
3926                                 return $this->mDbkeyform == '';
3927                         case NS_MEDIAWIKI:
3928                                 // known system message
3929                                 return $this->hasSourceText() !== false;
3930                         default:
3931                                 return false;
3932                 }
3933         }
3934
3935         /**
3936          * Does this title refer to a page that can (or might) be meaningfully
3937          * viewed?  In particular, this function may be used to determine if
3938          * links to the title should be rendered as "bluelinks" (as opposed to
3939          * "redlinks" to non-existent pages).
3940          *
3941          * @return Bool
3942          */
3943         public function isKnown() {
3944                 return $this->isAlwaysKnown() || $this->exists();
3945         }
3946
3947         /**
3948          * Does this page have source text?
3949          *
3950          * @return Boolean
3951          */
3952         public function hasSourceText() {
3953                 if ( $this->exists() ) {
3954                         return true;
3955                 }
3956
3957                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3958                         // If the page doesn't exist but is a known system message, default
3959                         // message content will be displayed, same for language subpages-
3960                         // Use always content language to avoid loading hundreds of languages
3961                         // to get the link color.
3962                         global $wgContLang;
3963                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3964                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
3965                         return $message->exists();
3966                 }
3967
3968                 return false;
3969         }
3970
3971         /**
3972          * Get the default message text or false if the message doesn't exist
3973          *
3974          * @return String or false
3975          */
3976         public function getDefaultMessageText() {
3977                 global $wgContLang;
3978
3979                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3980                         return false;
3981                 }
3982
3983                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3984                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3985
3986                 if ( $message->exists() ) {
3987                         return $message->plain();
3988                 } else {
3989                         return false;
3990                 }
3991         }
3992
3993         /**
3994          * Is this in a namespace that allows actual pages?
3995          *
3996          * @return Bool
3997          * @internal note -- uses hardcoded namespace index instead of constants
3998          */
3999         public function canExist() {
4000                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
4001         }
4002
4003         /**
4004          * Update page_touched timestamps and send squid purge messages for
4005          * pages linking to this title. May be sent to the job queue depending
4006          * on the number of links. Typically called on create and delete.
4007          */
4008         public function touchLinks() {
4009                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4010                 $u->doUpdate();
4011
4012                 if ( $this->getNamespace() == NS_CATEGORY ) {
4013                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4014                         $u->doUpdate();
4015                 }
4016         }
4017
4018         /**
4019          * Get the last touched timestamp
4020          *
4021          * @param $db DatabaseBase: optional db
4022          * @return String last-touched timestamp
4023          */
4024         public function getTouched( $db = null ) {
4025                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4026                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4027                 return $touched;
4028         }
4029
4030         /**
4031          * Get the timestamp when this page was updated since the user last saw it.
4032          *
4033          * @param $user User
4034          * @return String|Null
4035          */
4036         public function getNotificationTimestamp( $user = null ) {
4037                 global $wgUser, $wgShowUpdatedMarker;
4038                 // Assume current user if none given
4039                 if ( !$user ) {
4040                         $user = $wgUser;
4041                 }
4042                 // Check cache first
4043                 $uid = $user->getId();
4044                 // avoid isset here, as it'll return false for null entries
4045                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4046                         return $this->mNotificationTimestamp[$uid];
4047                 }
4048                 if ( !$uid || !$wgShowUpdatedMarker ) {
4049                         return $this->mNotificationTimestamp[$uid] = false;
4050                 }
4051                 // Don't cache too much!
4052                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4053                         $this->mNotificationTimestamp = array();
4054                 }
4055                 $dbr = wfGetDB( DB_SLAVE );
4056                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4057                         'wl_notificationtimestamp',
4058                         array( 'wl_namespace' => $this->getNamespace(),
4059                                 'wl_title' => $this->getDBkey(),
4060                                 'wl_user' => $user->getId()
4061                         ),
4062                         __METHOD__
4063                 );
4064                 return $this->mNotificationTimestamp[$uid];
4065         }
4066
4067         /**
4068          * Get the trackback URL for this page
4069          *
4070          * @return String Trackback URL
4071          */
4072         public function trackbackURL() {
4073                 global $wgScriptPath, $wgServer, $wgScriptExtension;
4074
4075                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
4076                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
4077         }
4078
4079         /**
4080          * Get the trackback RDF for this page
4081          *
4082          * @return String Trackback RDF
4083          */
4084         public function trackbackRDF() {
4085                 $url = htmlspecialchars( $this->getFullURL() );
4086                 $title = htmlspecialchars( $this->getText() );
4087                 $tburl = $this->trackbackURL();
4088
4089                 // Autodiscovery RDF is placed in comments so HTML validator
4090                 // won't barf. This is a rather icky workaround, but seems
4091                 // frequently used by this kind of RDF thingy.
4092                 //
4093                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4094                 return "<!--
4095 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4096                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4097                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4098 <rdf:Description
4099    rdf:about=\"$url\"
4100    dc:identifier=\"$url\"
4101    dc:title=\"$title\"
4102    trackback:ping=\"$tburl\" />
4103 </rdf:RDF>
4104 -->";
4105         }
4106
4107         /**
4108          * Generate strings used for xml 'id' names in monobook tabs
4109          *
4110          * @param $prepend string defaults to 'nstab-'
4111          * @return String XML 'id' name
4112          */
4113         public function getNamespaceKey( $prepend = 'nstab-' ) {
4114                 global $wgContLang;
4115                 // Gets the subject namespace if this title
4116                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4117                 // Checks if cononical namespace name exists for namespace
4118                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4119                         // Uses canonical namespace name
4120                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4121                 } else {
4122                         // Uses text of namespace
4123                         $namespaceKey = $this->getSubjectNsText();
4124                 }
4125                 // Makes namespace key lowercase
4126                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4127                 // Uses main
4128                 if ( $namespaceKey == '' ) {
4129                         $namespaceKey = 'main';
4130                 }
4131                 // Changes file to image for backwards compatibility
4132                 if ( $namespaceKey == 'file' ) {
4133                         $namespaceKey = 'image';
4134                 }
4135                 return $prepend . $namespaceKey;
4136         }
4137
4138         /**
4139          * Returns true if this is a special page.
4140          *
4141          * @return boolean
4142          */
4143         public function isSpecialPage() {
4144                 return $this->getNamespace() == NS_SPECIAL;
4145         }
4146
4147         /**
4148          * Returns true if this title resolves to the named special page
4149          *
4150          * @param $name String The special page name
4151          * @return boolean
4152          */
4153         public function isSpecial( $name ) {
4154                 if ( $this->getNamespace() == NS_SPECIAL ) {
4155                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4156                         if ( $name == $thisName ) {
4157                                 return true;
4158                         }
4159                 }
4160                 return false;
4161         }
4162
4163         /**
4164          * If the Title refers to a special page alias which is not the local default, resolve
4165          * the alias, and localise the name as necessary.  Otherwise, return $this
4166          *
4167          * @return Title
4168          */
4169         public function fixSpecialName() {
4170                 if ( $this->getNamespace() == NS_SPECIAL ) {
4171                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4172                         if ( $canonicalName ) {
4173                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
4174                                 if ( $localName != $this->mDbkeyform ) {
4175                                         return Title::makeTitle( NS_SPECIAL, $localName );
4176                                 }
4177                         }
4178                 }
4179                 return $this;
4180         }
4181
4182         /**
4183          * Is this Title in a namespace which contains content?
4184          * In other words, is this a content page, for the purposes of calculating
4185          * statistics, etc?
4186          *
4187          * @return Boolean
4188          */
4189         public function isContentPage() {
4190                 return MWNamespace::isContent( $this->getNamespace() );
4191         }
4192
4193         /**
4194          * Get all extant redirects to this Title
4195          *
4196          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4197          * @return Array of Title redirects to this title
4198          */
4199         public function getRedirectsHere( $ns = null ) {
4200                 $redirs = array();
4201
4202                 $dbr = wfGetDB( DB_SLAVE );
4203                 $where = array(
4204                         'rd_namespace' => $this->getNamespace(),
4205                         'rd_title' => $this->getDBkey(),
4206                         'rd_from = page_id'
4207                 );
4208                 if ( !is_null( $ns ) ) {
4209                         $where['page_namespace'] = $ns;
4210                 }
4211
4212                 $res = $dbr->select(
4213                         array( 'redirect', 'page' ),
4214                         array( 'page_namespace', 'page_title' ),
4215                         $where,
4216                         __METHOD__
4217                 );
4218
4219                 foreach ( $res as $row ) {
4220                         $redirs[] = self::newFromRow( $row );
4221                 }
4222                 return $redirs;
4223         }
4224
4225         /**
4226          * Check if this Title is a valid redirect target
4227          *
4228          * @return Bool
4229          */
4230         public function isValidRedirectTarget() {
4231                 global $wgInvalidRedirectTargets;
4232
4233                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4234                 if ( $this->isSpecial( 'Userlogout' ) ) {
4235                         return false;
4236                 }
4237
4238                 foreach ( $wgInvalidRedirectTargets as $target ) {
4239                         if ( $this->isSpecial( $target ) ) {
4240                                 return false;
4241                         }
4242                 }
4243
4244                 return true;
4245         }
4246
4247         /**
4248          * Get a backlink cache object
4249          *
4250          * @return object BacklinkCache
4251          */
4252         function getBacklinkCache() {
4253                 if ( is_null( $this->mBacklinkCache ) ) {
4254                         $this->mBacklinkCache = new BacklinkCache( $this );
4255                 }
4256                 return $this->mBacklinkCache;
4257         }
4258
4259         /**
4260          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4261          *
4262          * @return Boolean
4263          */
4264         public function canUseNoindex() {
4265                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4266
4267                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4268                         ? $wgContentNamespaces
4269                         : $wgExemptFromUserRobotsControl;
4270
4271                 return !in_array( $this->mNamespace, $bannedNamespaces );
4272
4273         }
4274
4275         /**
4276          * Returns restriction types for the current Title
4277          *
4278          * @return array applicable restriction types
4279          */
4280         public function getRestrictionTypes() {
4281                 if ( $this->getNamespace() == NS_SPECIAL ) {
4282                         return array();
4283                 }
4284
4285                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4286
4287                 if ( $this->getNamespace() != NS_FILE ) {
4288                         # Remove the upload restriction for non-file titles
4289                         $types = array_diff( $types, array( 'upload' ) );
4290                 }
4291
4292                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4293
4294                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4295                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4296
4297                 return $types;
4298         }
4299         /**
4300          * Get a filtered list of all restriction types supported by this wiki.
4301          * @param bool $exists True to get all restriction types that apply to
4302          * titles that do exist, False for all restriction types that apply to
4303          * titles that do not exist
4304          * @return array
4305          */
4306         public static function getFilteredRestrictionTypes( $exists = true ) {
4307                 global $wgRestrictionTypes;
4308                 $types = $wgRestrictionTypes;
4309                 if ( $exists ) {
4310                         # Remove the create restriction for existing titles
4311                         $types = array_diff( $types, array( 'create' ) );
4312                 } else {
4313                         # Only the create and upload restrictions apply to non-existing titles
4314                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4315                 }
4316                 return $types;
4317         }
4318
4319         /**
4320          * Returns the raw sort key to be used for categories, with the specified
4321          * prefix.  This will be fed to Collation::getSortKey() to get a
4322          * binary sortkey that can be used for actual sorting.
4323          *
4324          * @param $prefix string The prefix to be used, specified using
4325          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4326          *   prefix.
4327          * @return string
4328          */
4329         public function getCategorySortkey( $prefix = '' ) {
4330                 $unprefixed = $this->getText();
4331
4332                 // Anything that uses this hook should only depend
4333                 // on the Title object passed in, and should probably
4334                 // tell the users to run updateCollations.php --force
4335                 // in order to re-sort existing category relations.
4336                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4337                 if ( $prefix !== '' ) {
4338                         # Separate with a line feed, so the unprefixed part is only used as
4339                         # a tiebreaker when two pages have the exact same prefix.
4340                         # In UCA, tab is the only character that can sort above LF
4341                         # so we strip both of them from the original prefix.
4342                         $prefix = strtr( $prefix, "\n\t", '  ' );
4343                         return "$prefix\n$unprefixed";
4344                 }
4345                 return $unprefixed;
4346         }
4347
4348         /**
4349          * Get the language in which the content of this page is written.
4350          * Defaults to $wgContLang, but in certain cases it can be e.g.
4351          * $wgLang (such as special pages, which are in the user language).
4352          *
4353          * @since 1.18
4354          * @return object Language
4355          */
4356         public function getPageLanguage() {
4357                 global $wgLang;
4358                 if ( $this->getNamespace() == NS_SPECIAL ) {
4359                         // special pages are in the user language
4360                         return $wgLang;
4361                 } elseif ( $this->isCssOrJsPage() ) {
4362                         // css/js should always be LTR and is, in fact, English
4363                         return wfGetLangObj( 'en' );
4364                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4365                         // Parse mediawiki messages with correct target language
4366                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4367                         return wfGetLangObj( $lang );
4368                 }
4369                 global $wgContLang;
4370                 // If nothing special, it should be in the wiki content language
4371                 $pageLang = $wgContLang;
4372                 // Hook at the end because we don't want to override the above stuff
4373                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4374                 return wfGetLangObj( $pageLang );
4375         }
4376 }