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                                 $page = WikiPage::factory( $title );
 391                                 $newtitle = $page->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                 # Hand off all the decisions on urls to getLocalURL
 847                 $url = $this->getLocalURL( $query, $variant );
 848
 849                 # Expand the url to make it a full url. Note that getLocalURL has the
 850                 # potential to output full urls for a variety of reasons, so we use
 851                 # wfExpandUrl instead of simply prepending $wgServer
 852                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
 853
 854                 # Finally, add the fragment.
 855                 $url .= $this->getFragmentForURL();
 856
 857                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query, $variant ) );
 858                 return $url;
 859         }
 860
 861         /**
 862          * Get a URL with no fragment or server name.  If this page is generated
 863          * with action=render, $wgServer is prepended.
 864          *
 865          * @param $query Mixed: an optional query string; if not specified,
 866          *   $wgArticlePath will be used.  Can be specified as an associative array
 867          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 868          *   URL-escaped).
 869          * @param $variant String language variant of url (for sr, zh..)
 870          * @return String the URL
 871          */
 872         public function getLocalURL( $query = '', $variant = false ) {
 873                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 874                 global $wgVariantArticlePath;
 875
 876                 if ( is_array( $query ) ) {
 877                         $query = wfArrayToCGI( $query );
 878                 }
 879
 880                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 881                 if ( $interwiki ) {
 882                         $namespace = $this->getNsText();
 883                         if ( $namespace != '' ) {
 884                                 # Can this actually happen? Interwikis shouldn't be parsed.
 885                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 886                                 $namespace .= ':';
 887                         }
 888                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 889                         $url = wfAppendQuery( $url, $query );
 890                 } else {
 891                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 892                         if ( $query == '' ) {
 893                                 if ( $variant != false && $this->getPageLanguage()->hasVariants() ) {
 894                                         if ( !$wgVariantArticlePath ) {
 895                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 896                                         } else {
 897                                                 $variantArticlePath = $wgVariantArticlePath;
 898                                         }
 899                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 900                                         $url = str_replace( '$1', $dbkey, $url  );
 901                                 } else {
 902                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 903                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
 904                                 }
 905                         } else {
 906                                 global $wgActionPaths;
 907                                 $url = false;
 908                                 $matches = array();
 909                                 if ( !empty( $wgActionPaths ) &&
 910                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 911                                 {
 912                                         $action = urldecode( $matches[2] );
 913                                         if ( isset( $wgActionPaths[$action] ) ) {
 914                                                 $query = $matches[1];
 915                                                 if ( isset( $matches[4] ) ) {
 916                                                         $query .= $matches[4];
 917                                                 }
 918                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 919                                                 if ( $query != '' ) {
 920                                                         $url = wfAppendQuery( $url, $query );
 921                                                 }
 922                                         }
 923                                 }
 924
 925                                 if ( $url === false ) {
 926                                         if ( $query == '-' ) {
 927                                                 $query = '';
 928                                         }
 929                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 930                                 }
 931                         }
 932
 933                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
 934
 935                         // @todo FIXME: This causes breakage in various places when we
 936                         // actually expected a local URL and end up with dupe prefixes.
 937                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 938                                 $url = $wgServer . $url;
 939                         }
 940                 }
 941                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
 942                 return $url;
 943         }
 944
 945         /**
 946          * Get a URL that's the simplest URL that will be valid to link, locally,
 947          * to the current Title.  It includes the fragment, but does not include
 948          * the server unless action=render is used (or the link is external).  If
 949          * there's a fragment but the prefixed text is empty, we just return a link
 950          * to the fragment.
 951          *
 952          * The result obviously should not be URL-escaped, but does need to be
 953          * HTML-escaped if it's being output in HTML.
 954          *
 955          * @param $query Array of Strings An associative array of key => value pairs for the
 956          *   query string.  Keys and values will be escaped.
 957          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 958          *   for external links.  Default is "false" (same variant as current page,
 959          *   for anonymous users).
 960          * @return String the URL
 961          */
 962         public function getLinkUrl( $query = array(), $variant = false ) {
 963                 wfProfileIn( __METHOD__ );
 964                 if ( $this->isExternal() ) {
 965                         $ret = $this->getFullURL( $query );
 966                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 967                         $ret = $this->getFragmentForURL();
 968                 } else {
 969                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 970                 }
 971                 wfProfileOut( __METHOD__ );
 972                 return $ret;
 973         }
 974
 975         /**
 976          * Get an HTML-escaped version of the URL form, suitable for
 977          * using in a link, without a server name or fragment
 978          *
 979          * @param $query String an optional query string
 980          * @return String the URL
 981          */
 982         public function escapeLocalURL( $query = '' ) {
 983                 return htmlspecialchars( $this->getLocalURL( $query ) );
 984         }
 985
 986         /**
 987          * Get an HTML-escaped version of the URL form, suitable for
 988          * using in a link, including the server name and fragment
 989          *
 990          * @param $query String an optional query string
 991          * @return String the URL
 992          */
 993         public function escapeFullURL( $query = '' ) {
 994                 return htmlspecialchars( $this->getFullURL( $query ) );
 995         }
 996
 997         /**
 998          * HTML-escaped version of getCanonicalURL()
 999          */
1000         public function escapeCanonicalURL( $query = '', $variant = false ) {
1001                 return htmlspecialchars( $this->getCanonicalURL( $query, $variant ) );
1002         }
1003
1004         /**
1005          * Get the URL form for an internal link.
1006          * - Used in various Squid-related code, in case we have a different
1007          * internal hostname for the server from the exposed one.
1008          *
1009          * This uses $wgInternalServer to qualify the path, or $wgServer
1010          * if $wgInternalServer is not set. If the server variable used is
1011          * protocol-relative, the URL will be expanded to http://
1012          *
1013          * @param $query String an optional query string
1014          * @param $variant String language variant of url (for sr, zh..)
1015          * @return String the URL
1016          */
1017         public function getInternalURL( $query = '', $variant = false ) {
1018                 global $wgInternalServer, $wgServer;
1019                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1020                 $url = wfExpandUrl( $server . $this->getLocalURL( $query, $variant ), PROTO_HTTP );
1021                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query, $variant ) );
1022                 return $url;
1023         }
1024
1025         /**
1026          * Get the URL for a canonical link, for use in things like IRC and
1027          * e-mail notifications. Uses $wgCanonicalServer and the
1028          * GetCanonicalURL hook.
1029          *
1030          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1031          *
1032          * @param $query string An optional query string
1033          * @param $variant string Language variant of URL (for sr, zh, ...)
1034          * @return string The URL
1035          */
1036         public function getCanonicalURL( $query = '', $variant = false ) {
1037                 $url = wfExpandUrl( $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1038                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query, $variant ) );
1039                 return $url;
1040         }
1041
1042         /**
1043          * Get the edit URL for this Title
1044          *
1045          * @return String the URL, or a null string if this is an
1046          *  interwiki link
1047          */
1048         public function getEditURL() {
1049                 if ( $this->mInterwiki != '' ) {
1050                         return '';
1051                 }
1052                 $s = $this->getLocalURL( 'action=edit' );
1053
1054                 return $s;
1055         }
1056
1057         /**
1058          * Get the HTML-escaped displayable text form.
1059          * Used for the title field in <a> tags.
1060          *
1061          * @return String the text, including any prefixes
1062          */
1063         public function getEscapedText() {
1064                 return htmlspecialchars( $this->getPrefixedText() );
1065         }
1066
1067         /**
1068          * Is this Title interwiki?
1069          *
1070          * @return Bool
1071          */
1072         public function isExternal() {
1073                 return ( $this->mInterwiki != '' );
1074         }
1075
1076         /**
1077          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1078          *
1079          * @param $action String Action to check (default: edit)
1080          * @return Bool
1081          */
1082         public function isSemiProtected( $action = 'edit' ) {
1083                 if ( $this->exists() ) {
1084                         $restrictions = $this->getRestrictions( $action );
1085                         if ( count( $restrictions ) > 0 ) {
1086                                 foreach ( $restrictions as $restriction ) {
1087                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1088                                                 return false;
1089                                         }
1090                                 }
1091                         } else {
1092                                 # Not protected
1093                                 return false;
1094                         }
1095                         return true;
1096                 } else {
1097                         # If it doesn't exist, it can't be protected
1098                         return false;
1099                 }
1100         }
1101
1102         /**
1103          * Does the title correspond to a protected article?
1104          *
1105          * @param $action String the action the page is protected from,
1106          * by default checks all actions.
1107          * @return Bool
1108          */
1109         public function isProtected( $action = '' ) {
1110                 global $wgRestrictionLevels;
1111
1112                 $restrictionTypes = $this->getRestrictionTypes();
1113
1114                 # Special pages have inherent protection
1115                 if( $this->getNamespace() == NS_SPECIAL ) {
1116                         return true;
1117                 }
1118
1119                 # Check regular protection levels
1120                 foreach ( $restrictionTypes as $type ) {
1121                         if ( $action == $type || $action == '' ) {
1122                                 $r = $this->getRestrictions( $type );
1123                                 foreach ( $wgRestrictionLevels as $level ) {
1124                                         if ( in_array( $level, $r ) && $level != '' ) {
1125                                                 return true;
1126                                         }
1127                                 }
1128                         }
1129                 }
1130
1131                 return false;
1132         }
1133
1134         /**
1135          * Is this a conversion table for the LanguageConverter?
1136          *
1137          * @return Bool
1138          */
1139         public function isConversionTable() {
1140                 if(
1141                         $this->getNamespace() == NS_MEDIAWIKI &&
1142                         strpos( $this->getText(), 'Conversiontable' ) !== false
1143                 )
1144                 {
1145                         return true;
1146                 }
1147
1148                 return false;
1149         }
1150
1151         /**
1152          * Is $wgUser watching this page?
1153          *
1154          * @return Bool
1155          */
1156         public function userIsWatching() {
1157                 global $wgUser;
1158
1159                 if ( is_null( $this->mWatched ) ) {
1160                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1161                                 $this->mWatched = false;
1162                         } else {
1163                                 $this->mWatched = $wgUser->isWatched( $this );
1164                         }
1165                 }
1166                 return $this->mWatched;
1167         }
1168
1169         /**
1170          * Can $wgUser perform $action on this page?
1171          * This skips potentially expensive cascading permission checks
1172          * as well as avoids expensive error formatting
1173          *
1174          * Suitable for use for nonessential UI controls in common cases, but
1175          * _not_ for functional access control.
1176          *
1177          * May provide false positives, but should never provide a false negative.
1178          *
1179          * @param $action String action that permission needs to be checked for
1180          * @return Bool
1181          */
1182         public function quickUserCan( $action ) {
1183                 return $this->userCan( $action, false );
1184         }
1185
1186         /**
1187          * Determines if $user is unable to edit this page because it has been protected
1188          * by $wgNamespaceProtection.
1189          *
1190          * @param $user User object to check permissions
1191          * @return Bool
1192          */
1193         public function isNamespaceProtected( User $user ) {
1194                 global $wgNamespaceProtection;
1195
1196                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1197                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1198                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1199                                         return true;
1200                                 }
1201                         }
1202                 }
1203                 return false;
1204         }
1205
1206         /**
1207          * Can $wgUser perform $action on this page?
1208          *
1209          * @param $action String action that permission needs to be checked for
1210          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1211          * @return Bool
1212          */
1213         public function userCan( $action, $doExpensiveQueries = true ) {
1214                 global $wgUser;
1215                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1216         }
1217
1218         /**
1219          * Can $user perform $action on this page?
1220          *
1221          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1222          *
1223          * @param $action String action that permission needs to be checked for
1224          * @param $user User to check
1225          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1226          *   skipping checks for cascading protections and user blocks.
1227          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1228          * @return Array of arguments to wfMsg to explain permissions problems.
1229          */
1230         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1231                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1232
1233                 // Remove the errors being ignored.
1234                 foreach ( $errors as $index => $error ) {
1235                         $error_key = is_array( $error ) ? $error[0] : $error;
1236
1237                         if ( in_array( $error_key, $ignoreErrors ) ) {
1238                                 unset( $errors[$index] );
1239                         }
1240                 }
1241
1242                 return $errors;
1243         }
1244
1245         /**
1246          * Permissions checks that fail most often, and which are easiest to test.
1247          *
1248          * @param $action String the action to check
1249          * @param $user User user to check
1250          * @param $errors Array list of current errors
1251          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1252          * @param $short Boolean short circuit on first error
1253          *
1254          * @return Array list of errors
1255          */
1256         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1257                 $ns = $this->getNamespace();
1258
1259                 if ( $action == 'create' ) {
1260                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1261                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1262                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1263                         }
1264                 } elseif ( $action == 'move' ) {
1265                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1266                                         && $ns == NS_USER && !$this->isSubpage() ) {
1267                                 // Show user page-specific message only if the user can move other pages
1268                                 $errors[] = array( 'cant-move-user-page' );
1269                         }
1270
1271                         // Check if user is allowed to move files if it's a file
1272                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1273                                 $errors[] = array( 'movenotallowedfile' );
1274                         }
1275
1276                         if ( !$user->isAllowed( 'move', $ns) ) {
1277                                 // User can't move anything
1278
1279                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1280                                         array( 'user' ), $ns ), true );
1281                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1282                                         array( 'autoconfirmed' ), $ns ), true );
1283
1284                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1285                                         // custom message if logged-in users without any special rights can move
1286                                         $errors[] = array( 'movenologintext' );
1287                                 } else {
1288                                         $errors[] = array( 'movenotallowed' );
1289                                 }
1290                         }
1291                 } elseif ( $action == 'move-target' ) {
1292                         if ( !$user->isAllowed( 'move', $ns ) ) {
1293                                 // User can't move anything
1294                                 $errors[] = array( 'movenotallowed' );
1295                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1296                                         && $ns == NS_USER && !$this->isSubpage() ) {
1297                                 // Show user page-specific message only if the user can move other pages
1298                                 $errors[] = array( 'cant-move-to-user-page' );
1299                         }
1300                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1301                         // We avoid expensive display logic for quickUserCan's and such
1302                         $groups = false;
1303                         if ( !$short ) {
1304                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1305                                         User::getGroupsWithPermission( $action, $ns ) );
1306                         }
1307
1308                         if ( $groups ) {
1309                                 global $wgLang;
1310                                 $return = array(
1311                                         'badaccess-groups',
1312                                         $wgLang->commaList( $groups ),
1313                                         count( $groups )
1314                                 );
1315                         } else {
1316                                 $return = array( 'badaccess-group0' );
1317                         }
1318                         $errors[] = $return;
1319                 }
1320
1321                 return $errors;
1322         }
1323
1324         /**
1325          * Add the resulting error code to the errors array
1326          *
1327          * @param $errors Array list of current errors
1328          * @param $result Mixed result of errors
1329          *
1330          * @return Array list of errors
1331          */
1332         private function resultToError( $errors, $result ) {
1333                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1334                         // A single array representing an error
1335                         $errors[] = $result;
1336                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1337                         // A nested array representing multiple errors
1338                         $errors = array_merge( $errors, $result );
1339                 } elseif ( $result !== '' && is_string( $result ) ) {
1340                         // A string representing a message-id
1341                         $errors[] = array( $result );
1342                 } elseif ( $result === false ) {
1343                         // a generic "We don't want them to do that"
1344                         $errors[] = array( 'badaccess-group0' );
1345                 }
1346                 return $errors;
1347         }
1348
1349         /**
1350          * Check various permission hooks
1351          *
1352          * @param $action String the action to check
1353          * @param $user User user to check
1354          * @param $errors Array list of current errors
1355          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1356          * @param $short Boolean short circuit on first error
1357          *
1358          * @return Array list of errors
1359          */
1360         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1361                 // Use getUserPermissionsErrors instead
1362                 $result = '';
1363                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1364                         return $result ? array() : array( array( 'badaccess-group0' ) );
1365                 }
1366                 // Check getUserPermissionsErrors hook
1367                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1368                         $errors = $this->resultToError( $errors, $result );
1369                 }
1370                 // Check getUserPermissionsErrorsExpensive hook
1371                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1372                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1373                         $errors = $this->resultToError( $errors, $result );
1374                 }
1375
1376                 return $errors;
1377         }
1378
1379         /**
1380          * Check permissions on special pages & namespaces
1381          *
1382          * @param $action String the action to check
1383          * @param $user User user to check
1384          * @param $errors Array list of current errors
1385          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1386          * @param $short Boolean short circuit on first error
1387          *
1388          * @return Array list of errors
1389          */
1390         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1391                 # Only 'createaccount' and 'execute' can be performed on
1392                 # special pages, which don't actually exist in the DB.
1393                 $specialOKActions = array( 'createaccount', 'execute' );
1394                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1395                         $errors[] = array( 'ns-specialprotected' );
1396                 }
1397
1398                 # Check $wgNamespaceProtection for restricted namespaces
1399                 if ( $this->isNamespaceProtected( $user ) ) {
1400                         $ns = $this->mNamespace == NS_MAIN ?
1401                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1402                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1403                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1404                 }
1405
1406                 return $errors;
1407         }
1408
1409         /**
1410          * Check CSS/JS sub-page permissions
1411          *
1412          * @param $action String the action to check
1413          * @param $user User user to check
1414          * @param $errors Array list of current errors
1415          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1416          * @param $short Boolean short circuit on first error
1417          *
1418          * @return Array list of errors
1419          */
1420         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1421                 # Protect css/js subpages of user pages
1422                 # XXX: this might be better using restrictions
1423                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1424                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1425                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1426                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1427                                 $errors[] = array( 'customcssprotected' );
1428                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1429                                 $errors[] = array( 'customjsprotected' );
1430                         }
1431                 }
1432
1433                 return $errors;
1434         }
1435
1436         /**
1437          * Check against page_restrictions table requirements on this
1438          * page. The user must possess all required rights for this
1439          * action.
1440          *
1441          * @param $action String the action to check
1442          * @param $user User user to check
1443          * @param $errors Array list of current errors
1444          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1445          * @param $short Boolean short circuit on first error
1446          *
1447          * @return Array list of errors
1448          */
1449         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1450                 foreach ( $this->getRestrictions( $action ) as $right ) {
1451                         // Backwards compatibility, rewrite sysop -> protect
1452                         if ( $right == 'sysop' ) {
1453                                 $right = 'protect';
1454                         }
1455                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1456                                 // Users with 'editprotected' permission can edit protected pages
1457                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected', $this->mNamespace ) ) {
1458                                         // Users with 'editprotected' permission cannot edit protected pages
1459                                         // with cascading option turned on.
1460                                         if ( $this->mCascadeRestriction ) {
1461                                                 $errors[] = array( 'protectedpagetext', $right );
1462                                         }
1463                                 } else {
1464                                         $errors[] = array( 'protectedpagetext', $right );
1465                                 }
1466                         }
1467                 }
1468
1469                 return $errors;
1470         }
1471
1472         /**
1473          * Check restrictions on cascading pages.
1474          *
1475          * @param $action String the action to check
1476          * @param $user User to check
1477          * @param $errors Array list of current errors
1478          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1479          * @param $short Boolean short circuit on first error
1480          *
1481          * @return Array list of errors
1482          */
1483         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1484                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1485                         # We /could/ use the protection level on the source page, but it's
1486                         # fairly ugly as we have to establish a precedence hierarchy for pages
1487                         # included by multiple cascade-protected pages. So just restrict
1488                         # it to people with 'protect' permission, as they could remove the
1489                         # protection anyway.
1490                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1491                         # Cascading protection depends on more than this page...
1492                         # Several cascading protected pages may include this page...
1493                         # Check each cascading level
1494                         # This is only for protection restrictions, not for all actions
1495                         if ( isset( $restrictions[$action] ) ) {
1496                                 foreach ( $restrictions[$action] as $right ) {
1497                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1498                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1499                                                 $pages = '';
1500                                                 foreach ( $cascadingSources as $page )
1501                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1502                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1503                                         }
1504                                 }
1505                         }
1506                 }
1507
1508                 return $errors;
1509         }
1510
1511         /**
1512          * Check action permissions not already checked in checkQuickPermissions
1513          *
1514          * @param $action String the action to check
1515          * @param $user User to check
1516          * @param $errors Array list of current errors
1517          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1518          * @param $short Boolean short circuit on first error
1519          *
1520          * @return Array list of errors
1521          */
1522         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1523                 if ( $action == 'protect' ) {
1524                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1525                                 // If they can't edit, they shouldn't protect.
1526                                 $errors[] = array( 'protect-cantedit' );
1527                         }
1528                 } elseif ( $action == 'create' ) {
1529                         $title_protection = $this->getTitleProtection();
1530                         if( $title_protection ) {
1531                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1532                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1533                                 }
1534                                 if( $title_protection['pt_create_perm'] == '' ||
1535                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1536                                                 $this->mNamespace ) ) {
1537                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1538                                 }
1539                         }
1540                 } elseif ( $action == 'move' ) {
1541                         // Check for immobile pages
1542                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1543                                 // Specific message for this case
1544                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1545                         } elseif ( !$this->isMovable() ) {
1546                                 // Less specific message for rarer cases
1547                                 $errors[] = array( 'immobile-source-page' );
1548                         }
1549                 } elseif ( $action == 'move-target' ) {
1550                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1551                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1552                         } elseif ( !$this->isMovable() ) {
1553                                 $errors[] = array( 'immobile-target-page' );
1554                         }
1555                 }
1556                 return $errors;
1557         }
1558
1559         /**
1560          * Check that the user isn't blocked from editting.
1561          *
1562          * @param $action String the action to check
1563          * @param $user User to check
1564          * @param $errors Array list of current errors
1565          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1566          * @param $short Boolean short circuit on first error
1567          *
1568          * @return Array list of errors
1569          */
1570         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1571                 if( !$doExpensiveQueries ) {
1572                         return $errors;
1573                 }
1574
1575                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1576
1577                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1578                         $errors[] = array( 'confirmedittext' );
1579                 }
1580
1581                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1582                         // Edit blocks should not affect reading.
1583                         // Account creation blocks handled at userlogin.
1584                         // Unblocking handled in SpecialUnblock
1585                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1586                         // Don't block the user from editing their own talk page unless they've been
1587                         // explicitly blocked from that too.
1588                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1589                         $block = $user->mBlock;
1590
1591                         // This is from OutputPage::blockedPage
1592                         // Copied at r23888 by werdna
1593
1594                         $id = $user->blockedBy();
1595                         $reason = $user->blockedFor();
1596                         if ( $reason == '' ) {
1597                                 $reason = wfMsg( 'blockednoreason' );
1598                         }
1599                         $ip = $user->getRequest()->getIP();
1600
1601                         if ( is_numeric( $id ) ) {
1602                                 $name = User::whoIs( $id );
1603                         } else {
1604                                 $name = $id;
1605                         }
1606
1607                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1608                         $blockid = $block->getId();
1609                         $blockExpiry = $user->mBlock->mExpiry;
1610                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1611                         if ( $blockExpiry == 'infinity' ) {
1612                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1613                         } else {
1614                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1615                         }
1616
1617                         $intended = strval( $user->mBlock->getTarget() );
1618
1619                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1620                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1621                 }
1622
1623                 return $errors;
1624         }
1625
1626         /**
1627          * Can $user perform $action on this page? This is an internal function,
1628          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1629          * checks on wfReadOnly() and blocks)
1630          *
1631          * @param $action String action that permission needs to be checked for
1632          * @param $user User to check
1633          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1634          * @param $short Bool Set this to true to stop after the first permission error.
1635          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1636          */
1637         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1638                 wfProfileIn( __METHOD__ );
1639
1640                 $errors = array();
1641                 $checks = array(
1642                         'checkQuickPermissions',
1643                         'checkPermissionHooks',
1644                         'checkSpecialsAndNSPermissions',
1645                         'checkCSSandJSPermissions',
1646                         'checkPageRestrictions',
1647                         'checkCascadingSourcesRestrictions',
1648                         'checkActionPermissions',
1649                         'checkUserBlock'
1650                 );
1651
1652                 while( count( $checks ) > 0 &&
1653                            !( $short && count( $errors ) > 0 ) ) {
1654                         $method = array_shift( $checks );
1655                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1656                 }
1657
1658                 wfProfileOut( __METHOD__ );
1659                 return $errors;
1660         }
1661
1662         /**
1663          * Is this title subject to title protection?
1664          * Title protection is the one applied against creation of such title.
1665          *
1666          * @return Mixed An associative array representing any existent title
1667          *   protection, or false if there's none.
1668          */
1669         private function getTitleProtection() {
1670                 // Can't protect pages in special namespaces
1671                 if ( $this->getNamespace() < 0 ) {
1672                         return false;
1673                 }
1674
1675                 // Can't protect pages that exist.
1676                 if ( $this->exists() ) {
1677                         return false;
1678                 }
1679
1680                 if ( !isset( $this->mTitleProtection ) ) {
1681                         $dbr = wfGetDB( DB_SLAVE );
1682                         $res = $dbr->select( 'protected_titles', '*',
1683                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1684                                 __METHOD__ );
1685
1686                         // fetchRow returns false if there are no rows.
1687                         $this->mTitleProtection = $dbr->fetchRow( $res );
1688                 }
1689                 return $this->mTitleProtection;
1690         }
1691
1692         /**
1693          * Update the title protection status
1694          *
1695          * @param $create_perm String Permission required for creation
1696          * @param $reason String Reason for protection
1697          * @param $expiry String Expiry timestamp
1698          * @return boolean true
1699          */
1700         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1701                 global $wgUser, $wgContLang;
1702
1703                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1704                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1705                         // No change
1706                         return true;
1707                 }
1708
1709                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1710
1711                 $dbw = wfGetDB( DB_MASTER );
1712
1713                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1714
1715                 $expiry_description = '';
1716                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1717                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1718                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1719                 } else {
1720                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1721                 }
1722
1723                 # Update protection table
1724                 if ( $create_perm != '' ) {
1725                         $this->mTitleProtection = array(
1726                                         'pt_namespace' => $namespace,
1727                                         'pt_title' => $title,
1728                                         'pt_create_perm' => $create_perm,
1729                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1730                                         'pt_expiry' => $encodedExpiry,
1731                                         'pt_user' => $wgUser->getId(),
1732                                         'pt_reason' => $reason,
1733                                 );
1734                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1735                                 $this->mTitleProtection, __METHOD__     );
1736                 } else {
1737                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1738                                 'pt_title' => $title ), __METHOD__ );
1739                         $this->mTitleProtection = false;
1740                 }
1741
1742                 # Update the protection log
1743                 if ( $dbw->affectedRows() ) {
1744                         $log = new LogPage( 'protect' );
1745
1746                         if ( $create_perm ) {
1747                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1748                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1749                         } else {
1750                                 $log->addEntry( 'unprotect', $this, $reason );
1751                         }
1752                 }
1753
1754                 return true;
1755         }
1756
1757         /**
1758          * Remove any title protection due to page existing
1759          */
1760         public function deleteTitleProtection() {
1761                 $dbw = wfGetDB( DB_MASTER );
1762
1763                 $dbw->delete(
1764                         'protected_titles',
1765                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1766                         __METHOD__
1767                 );
1768                 $this->mTitleProtection = false;
1769         }
1770
1771         /**
1772          * Would anybody with sufficient privileges be able to move this page?
1773          * Some pages just aren't movable.
1774          *
1775          * @return Bool TRUE or FALSE
1776          */
1777         public function isMovable() {
1778                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
1779                         // Interwiki title or immovable namespace. Hooks don't get to override here
1780                         return false;
1781                 }
1782
1783                 $result = true;
1784                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1785                 return $result;
1786         }
1787
1788         /**
1789          * Can $wgUser read this page?
1790          *
1791          * @return Bool
1792          * @todo fold these checks into userCan()
1793          */
1794         public function userCanRead() {
1795                 global $wgUser, $wgGroupPermissions;
1796
1797                 static $useShortcut = null;
1798
1799                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1800                 if ( is_null( $useShortcut ) ) {
1801                         global $wgRevokePermissions;
1802                         $useShortcut = true;
1803                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1804                                 # Not a public wiki, so no shortcut
1805                                 $useShortcut = false;
1806                         } elseif ( !empty( $wgRevokePermissions ) ) {
1807                                 /**
1808                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1809                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1810                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1811                                  * reading is allowed.
1812                                  */
1813                                 foreach ( $wgRevokePermissions as $perms ) {
1814                                         if ( !empty( $perms['read'] ) ) {
1815                                                 # We might be removing the read right from the user, so no shortcut
1816                                                 $useShortcut = false;
1817                                                 break;
1818                                         }
1819                                 }
1820                         }
1821                 }
1822
1823                 $result = null;
1824                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1825                 if ( $result !== null ) {
1826                         return $result;
1827                 }
1828
1829                 # Shortcut for public wikis, allows skipping quite a bit of code
1830                 if ( $useShortcut ) {
1831                         return true;
1832                 }
1833
1834                 if ( $wgUser->isAllowed( 'read' ) ) {
1835                         return true;
1836                 } else {
1837                         global $wgWhitelistRead;
1838
1839                         # Always grant access to the login page.
1840                         # Even anons need to be able to log in.
1841                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1842                                 return true;
1843                         }
1844
1845                         # Bail out if there isn't whitelist
1846                         if ( !is_array( $wgWhitelistRead ) ) {
1847                                 return false;
1848                         }
1849
1850                         # Check for explicit whitelisting
1851                         $name = $this->getPrefixedText();
1852                         $dbName = $this->getPrefixedDBKey();
1853                         // Check with and without underscores
1854                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1855                                 return true;
1856
1857                         # Old settings might have the title prefixed with
1858                         # a colon for main-namespace pages
1859                         if ( $this->getNamespace() == NS_MAIN ) {
1860                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1861                                         return true;
1862                                 }
1863                         }
1864
1865                         # If it's a special page, ditch the subpage bit and check again
1866                         if ( $this->getNamespace() == NS_SPECIAL ) {
1867                                 $name = $this->getDBkey();
1868                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1869                                 if ( $name === false ) {
1870                                         # Invalid special page, but we show standard login required message
1871                                         return false;
1872                                 }
1873
1874                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1875                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1876                                         return true;
1877                                 }
1878                         }
1879
1880                 }
1881                 return false;
1882         }
1883
1884         /**
1885          * Is this the mainpage?
1886          * @note Title::newFromText seams to be sufficiently optimized by the title
1887          * cache that we don't need to over-optimize by doing direct comparisons and
1888          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1889          * ends up reporting something differently than $title->isMainPage();
1890          *
1891          * @since 1.18
1892          * @return Bool
1893          */
1894         public function isMainPage() {
1895                 return $this->equals( Title::newMainPage() );
1896         }
1897
1898         /**
1899          * Is this a talk page of some sort?
1900          *
1901          * @return Bool
1902          */
1903         public function isTalkPage() {
1904                 return MWNamespace::isTalk( $this->getNamespace() );
1905         }
1906
1907         /**
1908          * Is this a subpage?
1909          *
1910          * @return Bool
1911          */
1912         public function isSubpage() {
1913                 return MWNamespace::hasSubpages( $this->mNamespace )
1914                         ? strpos( $this->getText(), '/' ) !== false
1915                         : false;
1916         }
1917
1918         /**
1919          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1920          *
1921          * @return Bool
1922          */
1923         public function hasSubpages() {
1924                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1925                         # Duh
1926                         return false;
1927                 }
1928
1929                 # We dynamically add a member variable for the purpose of this method
1930                 # alone to cache the result.  There's no point in having it hanging
1931                 # around uninitialized in every Title object; therefore we only add it
1932                 # if needed and don't declare it statically.
1933                 if ( isset( $this->mHasSubpages ) ) {
1934                         return $this->mHasSubpages;
1935                 }
1936
1937                 $subpages = $this->getSubpages( 1 );
1938                 if ( $subpages instanceof TitleArray ) {
1939                         return $this->mHasSubpages = (bool)$subpages->count();
1940                 }
1941                 return $this->mHasSubpages = false;
1942         }
1943
1944         /**
1945          * Get all subpages of this page.
1946          *
1947          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1948          * @return mixed TitleArray, or empty array if this page's namespace
1949          *  doesn't allow subpages
1950          */
1951         public function getSubpages( $limit = -1 ) {
1952                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1953                         return array();
1954                 }
1955
1956                 $dbr = wfGetDB( DB_SLAVE );
1957                 $conds['page_namespace'] = $this->getNamespace();
1958                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1959                 $options = array();
1960                 if ( $limit > -1 ) {
1961                         $options['LIMIT'] = $limit;
1962                 }
1963                 return $this->mSubpages = TitleArray::newFromResult(
1964                         $dbr->select( 'page',
1965                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1966                                 $conds,
1967                                 __METHOD__,
1968                                 $options
1969                         )
1970                 );
1971         }
1972
1973         /**
1974          * Does that page contain wikitext, or it is JS, CSS or whatever?
1975          *
1976          * @return Bool
1977          */
1978         public function isWikitextPage() {
1979                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
1980                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
1981                 return $retval;
1982         }
1983
1984         /**
1985          * Could this page contain custom CSS or JavaScript, based
1986          * on the title?
1987          *
1988          * @return Bool
1989          */
1990         public function isCssOrJsPage() {
1991                 $retval = $this->mNamespace == NS_MEDIAWIKI
1992                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1993                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
1994                 return $retval;
1995         }
1996
1997         /**
1998          * Is this a .css or .js subpage of a user page?
1999          * @return Bool
2000          */
2001         public function isCssJsSubpage() {
2002                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
2003         }
2004
2005         /**
2006          * Is this a *valid* .css or .js subpage of a user page?
2007          *
2008          * @return Bool
2009          * @deprecated since 1.17
2010          */
2011         public function isValidCssJsSubpage() {
2012                 return $this->isCssJsSubpage();
2013         }
2014
2015         /**
2016          * Trim down a .css or .js subpage title to get the corresponding skin name
2017          *
2018          * @return string containing skin name from .css or .js subpage title
2019          */
2020         public function getSkinFromCssJsSubpage() {
2021                 $subpage = explode( '/', $this->mTextform );
2022                 $subpage = $subpage[ count( $subpage ) - 1 ];
2023                 $lastdot = strrpos( $subpage, '.' );
2024                 if ( $lastdot === false )
2025                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
2026                 return substr( $subpage, 0, $lastdot );
2027         }
2028
2029         /**
2030          * Is this a .css subpage of a user page?
2031          *
2032          * @return Bool
2033          */
2034         public function isCssSubpage() {
2035                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2036         }
2037
2038         /**
2039          * Is this a .js subpage of a user page?
2040          *
2041          * @return Bool
2042          */
2043         public function isJsSubpage() {
2044                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2045         }
2046
2047         /**
2048          * Protect css subpages of user pages: can $wgUser edit
2049          * this page?
2050          *
2051          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2052          * @return Bool
2053          */
2054         public function userCanEditCssSubpage() {
2055                 global $wgUser;
2056                 wfDeprecated( __METHOD__ );
2057                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2058                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2059         }
2060
2061         /**
2062          * Protect js subpages of user pages: can $wgUser edit
2063          * this page?
2064          *
2065          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2066          * @return Bool
2067          */
2068         public function userCanEditJsSubpage() {
2069                 global $wgUser;
2070                 wfDeprecated( __METHOD__ );
2071                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2072                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2073         }
2074
2075         /**
2076          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2077          *
2078          * @return Bool If the page is subject to cascading restrictions.
2079          */
2080         public function isCascadeProtected() {
2081                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2082                 return ( $sources > 0 );
2083         }
2084
2085         /**
2086          * Cascading protection: Get the source of any cascading restrictions on this page.
2087          *
2088          * @param $getPages Bool Whether or not to retrieve the actual pages
2089          *        that the restrictions have come from.
2090          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2091          *     have come, false for none, or true if such restrictions exist, but $getPages
2092          *     was not set.  The restriction array is an array of each type, each of which
2093          *     contains a array of unique groups.
2094          */
2095         public function getCascadeProtectionSources( $getPages = true ) {
2096                 global $wgContLang;
2097                 $pagerestrictions = array();
2098
2099                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2100                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2101                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2102                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2103                 }
2104
2105                 wfProfileIn( __METHOD__ );
2106
2107                 $dbr = wfGetDB( DB_SLAVE );
2108
2109                 if ( $this->getNamespace() == NS_FILE ) {
2110                         $tables = array( 'imagelinks', 'page_restrictions' );
2111                         $where_clauses = array(
2112                                 'il_to' => $this->getDBkey(),
2113                                 'il_from=pr_page',
2114                                 'pr_cascade' => 1
2115                         );
2116                 } else {
2117                         $tables = array( 'templatelinks', 'page_restrictions' );
2118                         $where_clauses = array(
2119                                 'tl_namespace' => $this->getNamespace(),
2120                                 'tl_title' => $this->getDBkey(),
2121                                 'tl_from=pr_page',
2122                                 'pr_cascade' => 1
2123                         );
2124                 }
2125
2126                 if ( $getPages ) {
2127                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2128                                                    'pr_expiry', 'pr_type', 'pr_level' );
2129                         $where_clauses[] = 'page_id=pr_page';
2130                         $tables[] = 'page';
2131                 } else {
2132                         $cols = array( 'pr_expiry' );
2133                 }
2134
2135                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2136
2137                 $sources = $getPages ? array() : false;
2138                 $now = wfTimestampNow();
2139                 $purgeExpired = false;
2140
2141                 foreach ( $res as $row ) {
2142                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2143                         if ( $expiry > $now ) {
2144                                 if ( $getPages ) {
2145                                         $page_id = $row->pr_page;
2146                                         $page_ns = $row->page_namespace;
2147                                         $page_title = $row->page_title;
2148                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2149                                         # Add groups needed for each restriction type if its not already there
2150                                         # Make sure this restriction type still exists
2151
2152                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2153                                                 $pagerestrictions[$row->pr_type] = array();
2154                                         }
2155
2156                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2157                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2158                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2159                                         }
2160                                 } else {
2161                                         $sources = true;
2162                                 }
2163                         } else {
2164                                 // Trigger lazy purge of expired restrictions from the db
2165                                 $purgeExpired = true;
2166                         }
2167                 }
2168                 if ( $purgeExpired ) {
2169                         Title::purgeExpiredRestrictions();
2170                 }
2171
2172                 if ( $getPages ) {
2173                         $this->mCascadeSources = $sources;
2174                         $this->mCascadingRestrictions = $pagerestrictions;
2175                 } else {
2176                         $this->mHasCascadingRestrictions = $sources;
2177                 }
2178
2179                 wfProfileOut( __METHOD__ );
2180                 return array( $sources, $pagerestrictions );
2181         }
2182
2183         /**
2184          * Returns cascading restrictions for the current article
2185          *
2186          * @return Boolean
2187          */
2188         function areRestrictionsCascading() {
2189                 if ( !$this->mRestrictionsLoaded ) {
2190                         $this->loadRestrictions();
2191                 }
2192
2193                 return $this->mCascadeRestriction;
2194         }
2195
2196         /**
2197          * Loads a string into mRestrictions array
2198          *
2199          * @param $res Resource restrictions as an SQL result.
2200          * @param $oldFashionedRestrictions String comma-separated list of page
2201          *        restrictions from page table (pre 1.10)
2202          */
2203         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2204                 $rows = array();
2205
2206                 foreach ( $res as $row ) {
2207                         $rows[] = $row;
2208                 }
2209
2210                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2211         }
2212
2213         /**
2214          * Compiles list of active page restrictions from both page table (pre 1.10)
2215          * and page_restrictions table for this existing page.
2216          * Public for usage by LiquidThreads.
2217          *
2218          * @param $rows array of db result objects
2219          * @param $oldFashionedRestrictions string comma-separated list of page
2220          *        restrictions from page table (pre 1.10)
2221          */
2222         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2223                 global $wgContLang;
2224                 $dbr = wfGetDB( DB_SLAVE );
2225
2226                 $restrictionTypes = $this->getRestrictionTypes();
2227
2228                 foreach ( $restrictionTypes as $type ) {
2229                         $this->mRestrictions[$type] = array();
2230                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2231                 }
2232
2233                 $this->mCascadeRestriction = false;
2234
2235                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2236
2237                 if ( $oldFashionedRestrictions === null ) {
2238                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2239                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2240                 }
2241
2242                 if ( $oldFashionedRestrictions != '' ) {
2243
2244                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2245                                 $temp = explode( '=', trim( $restrict ) );
2246                                 if ( count( $temp ) == 1 ) {
2247                                         // old old format should be treated as edit/move restriction
2248                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2249                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2250                                 } else {
2251                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2252                                 }
2253                         }
2254
2255                         $this->mOldRestrictions = true;
2256
2257                 }
2258
2259                 if ( count( $rows ) ) {
2260                         # Current system - load second to make them override.
2261                         $now = wfTimestampNow();
2262                         $purgeExpired = false;
2263
2264                         # Cycle through all the restrictions.
2265                         foreach ( $rows as $row ) {
2266
2267                                 // Don't take care of restrictions types that aren't allowed
2268                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2269                                         continue;
2270
2271                                 // This code should be refactored, now that it's being used more generally,
2272                                 // But I don't really see any harm in leaving it in Block for now -werdna
2273                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2274
2275                                 // Only apply the restrictions if they haven't expired!
2276                                 if ( !$expiry || $expiry > $now ) {
2277                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2278                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2279
2280                                         $this->mCascadeRestriction |= $row->pr_cascade;
2281                                 } else {
2282                                         // Trigger a lazy purge of expired restrictions
2283                                         $purgeExpired = true;
2284                                 }
2285                         }
2286
2287                         if ( $purgeExpired ) {
2288                                 Title::purgeExpiredRestrictions();
2289                         }
2290                 }
2291
2292                 $this->mRestrictionsLoaded = true;
2293         }
2294
2295         /**
2296          * Load restrictions from the page_restrictions table
2297          *
2298          * @param $oldFashionedRestrictions String comma-separated list of page
2299          *        restrictions from page table (pre 1.10)
2300          */
2301         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2302                 global $wgContLang;
2303                 if ( !$this->mRestrictionsLoaded ) {
2304                         if ( $this->exists() ) {
2305                                 $dbr = wfGetDB( DB_SLAVE );
2306
2307                                 $res = $dbr->select(
2308                                         'page_restrictions',
2309                                         '*',
2310                                         array( 'pr_page' => $this->getArticleId() ),
2311                                         __METHOD__
2312                                 );
2313
2314                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2315                         } else {
2316                                 $title_protection = $this->getTitleProtection();
2317
2318                                 if ( $title_protection ) {
2319                                         $now = wfTimestampNow();
2320                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2321
2322                                         if ( !$expiry || $expiry > $now ) {
2323                                                 // Apply the restrictions
2324                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2325                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2326                                         } else { // Get rid of the old restrictions
2327                                                 Title::purgeExpiredRestrictions();
2328                                                 $this->mTitleProtection = false;
2329                                         }
2330                                 } else {
2331                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2332                                 }
2333                                 $this->mRestrictionsLoaded = true;
2334                         }
2335                 }
2336         }
2337
2338         /**
2339          * Purge expired restrictions from the page_restrictions table
2340          */
2341         static function purgeExpiredRestrictions() {
2342                 $dbw = wfGetDB( DB_MASTER );
2343                 $dbw->delete(
2344                         'page_restrictions',
2345                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2346                         __METHOD__
2347                 );
2348
2349                 $dbw->delete(
2350                         'protected_titles',
2351                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2352                         __METHOD__
2353                 );
2354         }
2355
2356         /**
2357          * Accessor/initialisation for mRestrictions
2358          *
2359          * @param $action String action that permission needs to be checked for
2360          * @return Array of Strings the array of groups allowed to edit this article
2361          */
2362         public function getRestrictions( $action ) {
2363                 if ( !$this->mRestrictionsLoaded ) {
2364                         $this->loadRestrictions();
2365                 }
2366                 return isset( $this->mRestrictions[$action] )
2367                                 ? $this->mRestrictions[$action]
2368                                 : array();
2369         }
2370
2371         /**
2372          * Get the expiry time for the restriction against a given action
2373          *
2374          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2375          *      or not protected at all, or false if the action is not recognised.
2376          */
2377         public function getRestrictionExpiry( $action ) {
2378                 if ( !$this->mRestrictionsLoaded ) {
2379                         $this->loadRestrictions();
2380                 }
2381                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2382         }
2383
2384         /**
2385          * Is there a version of this page in the deletion archive?
2386          *
2387          * @return Int the number of archived revisions
2388          */
2389         public function isDeleted() {
2390                 if ( $this->getNamespace() < 0 ) {
2391                         $n = 0;
2392                 } else {
2393                         $dbr = wfGetDB( DB_SLAVE );
2394
2395                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2396                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2397                                 __METHOD__
2398                         );
2399                         if ( $this->getNamespace() == NS_FILE ) {
2400                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2401                                         array( 'fa_name' => $this->getDBkey() ),
2402                                         __METHOD__
2403                                 );
2404                         }
2405                 }
2406                 return (int)$n;
2407         }
2408
2409         /**
2410          * Is there a version of this page in the deletion archive?
2411          *
2412          * @return Boolean
2413          */
2414         public function isDeletedQuick() {
2415                 if ( $this->getNamespace() < 0 ) {
2416                         return false;
2417                 }
2418                 $dbr = wfGetDB( DB_SLAVE );
2419                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2420                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2421                         __METHOD__
2422                 );
2423                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2424                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2425                                 array( 'fa_name' => $this->getDBkey() ),
2426                                 __METHOD__
2427                         );
2428                 }
2429                 return $deleted;
2430         }
2431
2432         /**
2433          * Get the article ID for this Title from the link cache,
2434          * adding it if necessary
2435          *
2436          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2437          *  for update
2438          * @return Int the ID
2439          */
2440         public function getArticleID( $flags = 0 ) {
2441                 if ( $this->getNamespace() < 0 ) {
2442                         return $this->mArticleID = 0;
2443                 }
2444                 $linkCache = LinkCache::singleton();
2445                 if ( $flags & self::GAID_FOR_UPDATE ) {
2446                         $oldUpdate = $linkCache->forUpdate( true );
2447                         $linkCache->clearLink( $this );
2448                         $this->mArticleID = $linkCache->addLinkObj( $this );
2449                         $linkCache->forUpdate( $oldUpdate );
2450                 } else {
2451                         if ( -1 == $this->mArticleID ) {
2452                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2453                         }
2454                 }
2455                 return $this->mArticleID;
2456         }
2457
2458         /**
2459          * Is this an article that is a redirect page?
2460          * Uses link cache, adding it if necessary
2461          *
2462          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2463          * @return Bool
2464          */
2465         public function isRedirect( $flags = 0 ) {
2466                 if ( !is_null( $this->mRedirect ) ) {
2467                         return $this->mRedirect;
2468                 }
2469                 # Calling getArticleID() loads the field from cache as needed
2470                 if ( !$this->getArticleID( $flags ) ) {
2471                         return $this->mRedirect = false;
2472                 }
2473                 $linkCache = LinkCache::singleton();
2474                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2475
2476                 return $this->mRedirect;
2477         }
2478
2479         /**
2480          * What is the length of this page?
2481          * Uses link cache, adding it if necessary
2482          *
2483          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2484          * @return Int
2485          */
2486         public function getLength( $flags = 0 ) {
2487                 if ( $this->mLength != -1 ) {
2488                         return $this->mLength;
2489                 }
2490                 # Calling getArticleID() loads the field from cache as needed
2491                 if ( !$this->getArticleID( $flags ) ) {
2492                         return $this->mLength = 0;
2493                 }
2494                 $linkCache = LinkCache::singleton();
2495                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2496
2497                 return $this->mLength;
2498         }
2499
2500         /**
2501          * What is the page_latest field for this page?
2502          *
2503          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2504          * @return Int or 0 if the page doesn't exist
2505          */
2506         public function getLatestRevID( $flags = 0 ) {
2507                 if ( $this->mLatestID !== false ) {
2508                         return intval( $this->mLatestID );
2509                 }
2510                 # Calling getArticleID() loads the field from cache as needed
2511                 if ( !$this->getArticleID( $flags ) ) {
2512                         return $this->mLatestID = 0;
2513                 }
2514                 $linkCache = LinkCache::singleton();
2515                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2516
2517                 return $this->mLatestID;
2518         }
2519
2520         /**
2521          * This clears some fields in this object, and clears any associated
2522          * keys in the "bad links" section of the link cache.
2523          *
2524          * - This is called from Article::doEdit() and Article::insertOn() to allow
2525          * loading of the new page_id. It's also called from
2526          * Article::doDeleteArticle()
2527          *
2528          * @param $newid Int the new Article ID
2529          */
2530         public function resetArticleID( $newid ) {
2531                 $linkCache = LinkCache::singleton();
2532                 $linkCache->clearLink( $this );
2533
2534                 if ( $newid === false ) {
2535                         $this->mArticleID = -1;
2536                 } else {
2537                         $this->mArticleID = intval( $newid );
2538                 }
2539                 $this->mRestrictionsLoaded = false;
2540                 $this->mRestrictions = array();
2541                 $this->mRedirect = null;
2542                 $this->mLength = -1;
2543                 $this->mLatestID = false;
2544         }
2545
2546         /**
2547          * Updates page_touched for this page; called from LinksUpdate.php
2548          *
2549          * @return Bool true if the update succeded
2550          */
2551         public function invalidateCache() {
2552                 if ( wfReadOnly() ) {
2553                         return false;
2554                 }
2555                 $dbw = wfGetDB( DB_MASTER );
2556                 $success = $dbw->update(
2557                         'page',
2558                         array( 'page_touched' => $dbw->timestamp() ),
2559                         $this->pageCond(),
2560                         __METHOD__
2561                 );
2562                 HTMLFileCache::clearFileCache( $this );
2563                 return $success;
2564         }
2565
2566         /**
2567          * Prefix some arbitrary text with the namespace or interwiki prefix
2568          * of this object
2569          *
2570          * @param $name String the text
2571          * @return String the prefixed text
2572          * @private
2573          */
2574         private function prefix( $name ) {
2575                 $p = '';
2576                 if ( $this->mInterwiki != '' ) {
2577                         $p = $this->mInterwiki . ':';
2578                 }
2579
2580                 if ( 0 != $this->mNamespace ) {
2581                         $p .= $this->getNsText() . ':';
2582                 }
2583                 return $p . $name;
2584         }
2585
2586         /**
2587          * Returns a simple regex that will match on characters and sequences invalid in titles.
2588          * Note that this doesn't pick up many things that could be wrong with titles, but that
2589          * replacing this regex with something valid will make many titles valid.
2590          *
2591          * @return String regex string
2592          */
2593         static function getTitleInvalidRegex() {
2594                 static $rxTc = false;
2595                 if ( !$rxTc ) {
2596                         # Matching titles will be held as illegal.
2597                         $rxTc = '/' .
2598                                 # Any character not allowed is forbidden...
2599                                 '[^' . Title::legalChars() . ']' .
2600                                 # URL percent encoding sequences interfere with the ability
2601                                 # to round-trip titles -- you can't link to them consistently.
2602                                 '|%[0-9A-Fa-f]{2}' .
2603                                 # XML/HTML character references produce similar issues.
2604                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2605                                 '|&#[0-9]+;' .
2606                                 '|&#x[0-9A-Fa-f]+;' .
2607                                 '/S';
2608                 }
2609
2610                 return $rxTc;
2611         }
2612
2613         /**
2614          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2615          *
2616          * @param $text String containing title to capitalize
2617          * @param $ns int namespace index, defaults to NS_MAIN
2618          * @return String containing capitalized title
2619          */
2620         public static function capitalize( $text, $ns = NS_MAIN ) {
2621                 global $wgContLang;
2622
2623                 if ( MWNamespace::isCapitalized( $ns ) ) {
2624                         return $wgContLang->ucfirst( $text );
2625                 } else {
2626                         return $text;
2627                 }
2628         }
2629
2630         /**
2631          * Secure and split - main initialisation function for this object
2632          *
2633          * Assumes that mDbkeyform has been set, and is urldecoded
2634          * and uses underscores, but not otherwise munged.  This function
2635          * removes illegal characters, splits off the interwiki and
2636          * namespace prefixes, sets the other forms, and canonicalizes
2637          * everything.
2638          *
2639          * @return Bool true on success
2640          */
2641         private function secureAndSplit() {
2642                 global $wgContLang, $wgLocalInterwiki;
2643
2644                 # Initialisation
2645                 $this->mInterwiki = $this->mFragment = '';
2646                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2647
2648                 $dbkey = $this->mDbkeyform;
2649
2650                 # Strip Unicode bidi override characters.
2651                 # Sometimes they slip into cut-n-pasted page titles, where the
2652                 # override chars get included in list displays.
2653                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2654
2655                 # Clean up whitespace
2656                 # Note: use of the /u option on preg_replace here will cause
2657                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2658                 # conveniently disabling them.
2659                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2660                 $dbkey = trim( $dbkey, '_' );
2661
2662                 if ( $dbkey == '' ) {
2663                         return false;
2664                 }
2665
2666                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2667                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2668                         return false;
2669                 }
2670
2671                 $this->mDbkeyform = $dbkey;
2672
2673                 # Initial colon indicates main namespace rather than specified default
2674                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2675                 if ( ':' == $dbkey[0] ) {
2676                         $this->mNamespace = NS_MAIN;
2677                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2678                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2679                 }
2680
2681                 # Namespace or interwiki prefix
2682                 $firstPass = true;
2683                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2684                 do {
2685                         $m = array();
2686                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2687                                 $p = $m[1];
2688                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2689                                         # Ordinary namespace
2690                                         $dbkey = $m[2];
2691                                         $this->mNamespace = $ns;
2692                                         # For Talk:X pages, check if X has a "namespace" prefix
2693                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2694                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2695                                                         # Disallow Talk:File:x type titles...
2696                                                         return false;
2697                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2698                                                         # Disallow Talk:Interwiki:x type titles...
2699                                                         return false;
2700                                                 }
2701                                         }
2702                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2703                                         if ( !$firstPass ) {
2704                                                 # Can't make a local interwiki link to an interwiki link.
2705                                                 # That's just crazy!
2706                                                 return false;
2707                                         }
2708
2709                                         # Interwiki link
2710                                         $dbkey = $m[2];
2711                                         $this->mInterwiki = $wgContLang->lc( $p );
2712
2713                                         # Redundant interwiki prefix to the local wiki
2714                                         if ( $wgLocalInterwiki !== false
2715                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2716                                         {
2717                                                 if ( $dbkey == '' ) {
2718                                                         # Can't have an empty self-link
2719                                                         return false;
2720                                                 }
2721                                                 $this->mInterwiki = '';
2722                                                 $firstPass = false;
2723                                                 # Do another namespace split...
2724                                                 continue;
2725                                         }
2726
2727                                         # If there's an initial colon after the interwiki, that also
2728                                         # resets the default namespace
2729                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2730                                                 $this->mNamespace = NS_MAIN;
2731                                                 $dbkey = substr( $dbkey, 1 );
2732                                         }
2733                                 }
2734                                 # If there's no recognized interwiki or namespace,
2735                                 # then let the colon expression be part of the title.
2736                         }
2737                         break;
2738                 } while ( true );
2739
2740                 # We already know that some pages won't be in the database!
2741                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2742                         $this->mArticleID = 0;
2743                 }
2744                 $fragment = strstr( $dbkey, '#' );
2745                 if ( false !== $fragment ) {
2746                         $this->setFragment( $fragment );
2747                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2748                         # remove whitespace again: prevents "Foo_bar_#"
2749                         # becoming "Foo_bar_"
2750                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2751                 }
2752
2753                 # Reject illegal characters.
2754                 $rxTc = self::getTitleInvalidRegex();
2755                 if ( preg_match( $rxTc, $dbkey ) ) {
2756                         return false;
2757                 }
2758
2759                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2760                 # reachable due to the way web browsers deal with 'relative' URLs.
2761                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2762                 if ( strpos( $dbkey, '.' ) !== false &&
2763                          ( $dbkey === '.' || $dbkey === '..' ||
2764                            strpos( $dbkey, './' ) === 0  ||
2765                            strpos( $dbkey, '../' ) === 0 ||
2766                            strpos( $dbkey, '/./' ) !== false ||
2767                            strpos( $dbkey, '/../' ) !== false  ||
2768                            substr( $dbkey, -2 ) == '/.' ||
2769                            substr( $dbkey, -3 ) == '/..' ) )
2770                 {
2771                         return false;
2772                 }
2773
2774                 # Magic tilde sequences? Nu-uh!
2775                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2776                         return false;
2777                 }
2778
2779                 # Limit the size of titles to 255 bytes. This is typically the size of the
2780                 # underlying database field. We make an exception for special pages, which
2781                 # don't need to be stored in the database, and may edge over 255 bytes due
2782                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2783                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2784                   strlen( $dbkey ) > 512 )
2785                 {
2786                         return false;
2787                 }
2788
2789                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2790                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2791                 # other site might be case-sensitive.
2792                 $this->mUserCaseDBKey = $dbkey;
2793                 if ( $this->mInterwiki == '' ) {
2794                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2795                 }
2796
2797                 # Can't make a link to a namespace alone... "empty" local links can only be
2798                 # self-links with a fragment identifier.
2799                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2800                         return false;
2801                 }
2802
2803                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2804                 // IP names are not allowed for accounts, and can only be referring to
2805                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2806                 // there are numerous ways to present the same IP. Having sp:contribs scan
2807                 // them all is silly and having some show the edits and others not is
2808                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2809                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2810                         ? IP::sanitizeIP( $dbkey )
2811                         : $dbkey;
2812
2813                 // Any remaining initial :s are illegal.
2814                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
2815                         return false;
2816                 }
2817
2818                 # Fill fields
2819                 $this->mDbkeyform = $dbkey;
2820                 $this->mUrlform = wfUrlencode( $dbkey );
2821
2822                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2823
2824                 return true;
2825         }
2826
2827         /**
2828          * Set the fragment for this title. Removes the first character from the
2829          * specified fragment before setting, so it assumes you're passing it with
2830          * an initial "#".
2831          *
2832          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2833          * Still in active use privately.
2834          *
2835          * @param $fragment String text
2836          */
2837         public function setFragment( $fragment ) {
2838                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2839         }
2840
2841         /**
2842          * Get a Title object associated with the talk page of this article
2843          *
2844          * @return Title the object for the talk page
2845          */
2846         public function getTalkPage() {
2847                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2848         }
2849
2850         /**
2851          * Get a title object associated with the subject page of this
2852          * talk page
2853          *
2854          * @return Title the object for the subject page
2855          */
2856         public function getSubjectPage() {
2857                 // Is this the same title?
2858                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2859                 if ( $this->getNamespace() == $subjectNS ) {
2860                         return $this;
2861                 }
2862                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2863         }
2864
2865         /**
2866          * Get an array of Title objects linking to this Title
2867          * Also stores the IDs in the link cache.
2868          *
2869          * WARNING: do not use this function on arbitrary user-supplied titles!
2870          * On heavily-used templates it will max out the memory.
2871          *
2872          * @param $options Array: may be FOR UPDATE
2873          * @param $table String: table name
2874          * @param $prefix String: fields prefix
2875          * @return Array of Title objects linking here
2876          */
2877         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2878                 $linkCache = LinkCache::singleton();
2879
2880                 if ( count( $options ) > 0 ) {
2881                         $db = wfGetDB( DB_MASTER );
2882                 } else {
2883                         $db = wfGetDB( DB_SLAVE );
2884                 }
2885
2886                 $res = $db->select(
2887                         array( 'page', $table ),
2888                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2889                         array(
2890                                 "{$prefix}_from=page_id",
2891                                 "{$prefix}_namespace" => $this->getNamespace(),
2892                                 "{$prefix}_title"     => $this->getDBkey() ),
2893                         __METHOD__,
2894                         $options
2895                 );
2896
2897                 $retVal = array();
2898                 if ( $db->numRows( $res ) ) {
2899                         foreach ( $res as $row ) {
2900                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2901                                 if ( $titleObj ) {
2902                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
2903                                         $retVal[] = $titleObj;
2904                                 }
2905                         }
2906                 }
2907                 return $retVal;
2908         }
2909
2910         /**
2911          * Get an array of Title objects using this Title as a template
2912          * Also stores the IDs in the link cache.
2913          *
2914          * WARNING: do not use this function on arbitrary user-supplied titles!
2915          * On heavily-used templates it will max out the memory.
2916          *
2917          * @param $options Array: may be FOR UPDATE
2918          * @return Array of Title the Title objects linking here
2919          */
2920         public function getTemplateLinksTo( $options = array() ) {
2921                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2922         }
2923
2924         /**
2925          * Get an array of Title objects referring to non-existent articles linked from this page
2926          *
2927          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2928          * @return Array of Title the Title objects
2929          */
2930         public function getBrokenLinksFrom() {
2931                 if ( $this->getArticleId() == 0 ) {
2932                         # All links from article ID 0 are false positives
2933                         return array();
2934                 }
2935
2936                 $dbr = wfGetDB( DB_SLAVE );
2937                 $res = $dbr->select(
2938                         array( 'page', 'pagelinks' ),
2939                         array( 'pl_namespace', 'pl_title' ),
2940                         array(
2941                                 'pl_from' => $this->getArticleId(),
2942                                 'page_namespace IS NULL'
2943                         ),
2944                         __METHOD__, array(),
2945                         array(
2946                                 'page' => array(
2947                                         'LEFT JOIN',
2948                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2949                                 )
2950                         )
2951                 );
2952
2953                 $retVal = array();
2954                 foreach ( $res as $row ) {
2955                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2956                 }
2957                 return $retVal;
2958         }
2959
2960
2961         /**
2962          * Get a list of URLs to purge from the Squid cache when this
2963          * page changes
2964          *
2965          * @return Array of String the URLs
2966          */
2967         public function getSquidURLs() {
2968                 global $wgContLang;
2969
2970                 $urls = array(
2971                         $this->getInternalURL(),
2972                         $this->getInternalURL( 'action=history' )
2973                 );
2974
2975                 // purge variant urls as well
2976                 if ( $wgContLang->hasVariants() ) {
2977                         $variants = $wgContLang->getVariants();
2978                         foreach ( $variants as $vCode ) {
2979                                 $urls[] = $this->getInternalURL( '', $vCode );
2980                         }
2981                 }
2982
2983                 return $urls;
2984         }
2985
2986         /**
2987          * Purge all applicable Squid URLs
2988          */
2989         public function purgeSquid() {
2990                 global $wgUseSquid;
2991                 if ( $wgUseSquid ) {
2992                         $urls = $this->getSquidURLs();
2993                         $u = new SquidUpdate( $urls );
2994                         $u->doUpdate();
2995                 }
2996         }
2997
2998         /**
2999          * Move this page without authentication
3000          *
3001          * @param $nt Title the new page Title
3002          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3003          */
3004         public function moveNoAuth( &$nt ) {
3005                 return $this->moveTo( $nt, false );
3006         }
3007
3008         /**
3009          * Check whether a given move operation would be valid.
3010          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3011          *
3012          * @param $nt Title the new title
3013          * @param $auth Bool indicates whether $wgUser's permissions
3014          *  should be checked
3015          * @param $reason String is the log summary of the move, used for spam checking
3016          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3017          */
3018         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3019                 global $wgUser;
3020
3021                 $errors = array();
3022                 if ( !$nt ) {
3023                         // Normally we'd add this to $errors, but we'll get
3024                         // lots of syntax errors if $nt is not an object
3025                         return array( array( 'badtitletext' ) );
3026                 }
3027                 if ( $this->equals( $nt ) ) {
3028                         $errors[] = array( 'selfmove' );
3029                 }
3030                 if ( !$this->isMovable() ) {
3031                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3032                 }
3033                 if ( $nt->getInterwiki() != '' ) {
3034                         $errors[] = array( 'immobile-target-namespace-iw' );
3035                 }
3036                 if ( !$nt->isMovable() ) {
3037                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3038                 }
3039
3040                 $oldid = $this->getArticleID();
3041                 $newid = $nt->getArticleID();
3042
3043                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3044                         $errors[] = array( 'articleexists' );
3045                 }
3046                 if ( ( $this->getDBkey() == '' ) ||
3047                          ( !$oldid ) ||
3048                          ( $nt->getDBkey() == '' ) ) {
3049                         $errors[] = array( 'badarticleerror' );
3050                 }
3051
3052                 // Image-specific checks
3053                 if ( $this->getNamespace() == NS_FILE ) {
3054                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3055                 }
3056
3057                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3058                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3059                 }
3060
3061                 if ( $auth ) {
3062                         $errors = wfMergeErrorArrays( $errors,
3063                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3064                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3065                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3066                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3067                 }
3068
3069                 $match = EditPage::matchSummarySpamRegex( $reason );
3070                 if ( $match !== false ) {
3071                         // This is kind of lame, won't display nice
3072                         $errors[] = array( 'spamprotectiontext' );
3073                 }
3074
3075                 $err = null;
3076                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3077                         $errors[] = array( 'hookaborted', $err );
3078                 }
3079
3080                 # The move is allowed only if (1) the target doesn't exist, or
3081                 # (2) the target is a redirect to the source, and has no history
3082                 # (so we can undo bad moves right after they're done).
3083
3084                 if ( 0 != $newid ) { # Target exists; check for validity
3085                         if ( !$this->isValidMoveTarget( $nt ) ) {
3086                                 $errors[] = array( 'articleexists' );
3087                         }
3088                 } else {
3089                         $tp = $nt->getTitleProtection();
3090                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3091                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3092                                 $errors[] = array( 'cantmove-titleprotected' );
3093                         }
3094                 }
3095                 if ( empty( $errors ) ) {
3096                         return true;
3097                 }
3098                 return $errors;
3099         }
3100
3101         /**
3102          * Check if the requested move target is a valid file move target
3103          * @param Title $nt Target title
3104          * @return array List of errors
3105          */
3106         protected function validateFileMoveOperation( $nt ) {
3107                 global $wgUser;
3108
3109                 $errors = array();
3110
3111                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3112
3113                 $file = wfLocalFile( $this );
3114                 if ( $file->exists() ) {
3115                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3116                                 $errors[] = array( 'imageinvalidfilename' );
3117                         }
3118                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3119                                 $errors[] = array( 'imagetypemismatch' );
3120                         }
3121                 }
3122
3123                 if ( $nt->getNamespace() != NS_FILE ) {
3124                         $errors[] = array( 'imagenocrossnamespace' );
3125                         // From here we want to do checks on a file object, so if we can't
3126                         // create one, we must return.
3127                         return $errors;
3128                 }
3129
3130                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3131
3132                 $destFile = wfLocalFile( $nt );
3133                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3134                         $errors[] = array( 'file-exists-sharedrepo' );
3135                 }
3136
3137                 return $errors;
3138         }
3139
3140         /**
3141          * Move a title to a new location
3142          *
3143          * @param $nt Title the new title
3144          * @param $auth Bool indicates whether $wgUser's permissions
3145          *  should be checked
3146          * @param $reason String the reason for the move
3147          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3148          *  Ignored if the user doesn't have the suppressredirect right.
3149          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3150          */
3151         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3152                 global $wgUser;
3153                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3154                 if ( is_array( $err ) ) {
3155                         // Auto-block user's IP if the account was "hard" blocked
3156                         $wgUser->spreadAnyEditBlock();
3157                         return $err;
3158                 }
3159
3160                 // If it is a file, move it first.
3161                 // It is done before all other moving stuff is done because it's hard to revert.
3162                 $dbw = wfGetDB( DB_MASTER );
3163                 if ( $this->getNamespace() == NS_FILE ) {
3164                         $file = wfLocalFile( $this );
3165                         if ( $file->exists() ) {
3166                                 $status = $file->move( $nt );
3167                                 if ( !$status->isOk() ) {
3168                                         return $status->getErrorsArray();
3169                                 }
3170                         }
3171                 }
3172                 // Clear RepoGroup process cache
3173                 RepoGroup::singleton()->clearCache( $this );
3174                 RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3175
3176                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3177                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3178                 $protected = $this->isProtected();
3179                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3180
3181                 // Do the actual move
3182                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3183                 if ( is_array( $err ) ) {
3184                         # @todo FIXME: What about the File we have already moved?
3185                         $dbw->rollback();
3186                         return $err;
3187                 }
3188
3189                 $redirid = $this->getArticleID();
3190
3191                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3192                 // cl_timestamp, which may disturb time-based lists on some sites.
3193                 $prefixes = $dbw->select(
3194                         'categorylinks',
3195                         array( 'cl_sortkey_prefix', 'cl_to' ),
3196                         array( 'cl_from' => $pageid ),
3197                         __METHOD__
3198                 );
3199                 foreach ( $prefixes as $prefixRow ) {
3200                         $prefix = $prefixRow->cl_sortkey_prefix;
3201                         $catTo = $prefixRow->cl_to;
3202                         $dbw->update( 'categorylinks',
3203                                 array(
3204                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3205                                                 $nt->getCategorySortkey( $prefix ) ),
3206                                         'cl_timestamp=cl_timestamp' ),
3207                                 array(
3208                                         'cl_from' => $pageid,
3209                                         'cl_to' => $catTo ),
3210                                 __METHOD__
3211                         );
3212                 }
3213
3214                 if ( $protected ) {
3215                         # Protect the redirect title as the title used to be...
3216                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3217                                 array(
3218                                         'pr_page'    => $redirid,
3219                                         'pr_type'    => 'pr_type',
3220                                         'pr_level'   => 'pr_level',
3221                                         'pr_cascade' => 'pr_cascade',
3222                                         'pr_user'    => 'pr_user',
3223                                         'pr_expiry'  => 'pr_expiry'
3224                                 ),
3225                                 array( 'pr_page' => $pageid ),
3226                                 __METHOD__,
3227                                 array( 'IGNORE' )
3228                         );
3229                         # Update the protection log
3230                         $log = new LogPage( 'protect' );
3231                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3232                         if ( $reason ) {
3233                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3234                         }
3235                         // @todo FIXME: $params?
3236                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3237                 }
3238
3239                 # Update watchlists
3240                 $oldnamespace = $this->getNamespace() & ~1;
3241                 $newnamespace = $nt->getNamespace() & ~1;
3242                 $oldtitle = $this->getDBkey();
3243                 $newtitle = $nt->getDBkey();
3244
3245                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3246                         WatchedItem::duplicateEntries( $this, $nt );
3247                 }
3248
3249                 # Update search engine
3250                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3251                 $u->doUpdate();
3252                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3253                 $u->doUpdate();
3254
3255                 $dbw->commit();
3256
3257                 # Update site_stats
3258                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3259                         # No longer a content page
3260                         # Not viewed, edited, removing
3261                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3262                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3263                         # Now a content page
3264                         # Not viewed, edited, adding
3265                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3266                 } elseif ( $pageCountChange ) {
3267                         # Redirect added
3268                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3269                 } else {
3270                         # Nothing special
3271                         $u = false;
3272                 }
3273                 if ( $u ) {
3274                         $u->doUpdate();
3275                 }
3276
3277                 # Update message cache for interface messages
3278                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3279                         # @bug 17860: old article can be deleted, if this the case,
3280                         # delete it from message cache
3281                         if ( $this->getArticleID() === 0 ) {
3282                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3283                         } else {
3284                                 $rev = Revision::newFromTitle( $this );
3285                                 MessageCache::singleton()->replace( $this->getDBkey(), $rev->getText() );
3286                         }
3287                 }
3288                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3289                         $rev = Revision::newFromTitle( $nt );
3290                         MessageCache::singleton()->replace( $nt->getDBkey(), $rev->getText() );
3291                 }
3292
3293                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3294                 return true;
3295         }
3296
3297         /**
3298          * Move page to a title which is either a redirect to the
3299          * source page or nonexistent
3300          *
3301          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3302          * @param $reason String The reason for the move
3303          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3304          *   if the user doesn't have the suppressredirect right
3305          */
3306         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3307                 global $wgUser, $wgContLang;
3308
3309                 if ( $nt->exists() ) {
3310                         $moveOverRedirect = true;
3311                         $logType = 'move_redir';
3312                 } else {
3313                         $moveOverRedirect = false;
3314                         $logType = 'move';
3315                 }
3316
3317                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3318
3319                 $logEntry = new ManualLogEntry( 'move', $logType );
3320                 $logEntry->setPerformer( $wgUser );
3321                 $logEntry->setTarget( $this );
3322                 $logEntry->setComment( $reason );
3323                 $logEntry->setParameters( array(
3324                         '4::target' => $nt->getPrefixedText(),
3325                         '5::noredir' => $redirectSuppressed ? '1': '0',
3326                 ) );
3327
3328                 $formatter = LogFormatter::newFromEntry( $logEntry );
3329                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3330                 $comment = $formatter->getPlainActionText();
3331                 if ( $reason ) {
3332                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3333                 }
3334                 # Truncate for whole multibyte characters.
3335                 $comment = $wgContLang->truncate( $comment, 255 );
3336
3337                 $oldid = $this->getArticleID();
3338                 $latest = $this->getLatestRevID();
3339
3340                 $dbw = wfGetDB( DB_MASTER );
3341
3342                 if ( $moveOverRedirect ) {
3343                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3344
3345                         $newid = $nt->getArticleID();
3346                         $newns = $nt->getNamespace();
3347                         $newdbk = $nt->getDBkey();
3348
3349                         # Delete the old redirect. We don't save it to history since
3350                         # by definition if we've got here it's rather uninteresting.
3351                         # We have to remove it so that the next step doesn't trigger
3352                         # a conflict on the unique namespace+title index...
3353                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3354                         if ( !$dbw->cascadingDeletes() ) {
3355                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3356                                 global $wgUseTrackbacks;
3357                                 if ( $wgUseTrackbacks ) {
3358                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3359                                 }
3360                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3361                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3362                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3363                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3364                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3365                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3366                                 $dbw->delete( 'iwlinks', array( 'iwl_from' => $newid ), __METHOD__ );
3367                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3368                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3369                         }
3370                         // If the target page was recently created, it may have an entry in recentchanges still
3371                         $dbw->delete( 'recentchanges',
3372                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3373                                 __METHOD__
3374                         );
3375                 }
3376
3377                 # Save a null revision in the page's history notifying of the move
3378                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3379                 if ( !is_object( $nullRevision ) ) {
3380                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3381                 }
3382                 $nullRevId = $nullRevision->insertOn( $dbw );
3383
3384                 $now = wfTimestampNow();
3385                 # Change the name of the target page:
3386                 $dbw->update( 'page',
3387                         /* SET */ array(
3388                                 'page_touched'   => $dbw->timestamp( $now ),
3389                                 'page_namespace' => $nt->getNamespace(),
3390                                 'page_title'     => $nt->getDBkey(),
3391                                 'page_latest'    => $nullRevId,
3392                         ),
3393                         /* WHERE */ array( 'page_id' => $oldid ),
3394                         __METHOD__
3395                 );
3396                 $nt->resetArticleID( $oldid );
3397
3398                 $article = WikiPage::factory( $nt );
3399                 wfRunHooks( 'NewRevisionFromEditComplete',
3400                         array( $article, $nullRevision, $latest, $wgUser ) );
3401                 $article->setCachedLastEditTime( $now );
3402
3403                 # Recreate the redirect, this time in the other direction.
3404                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3405                         $mwRedir = MagicWord::get( 'redirect' );
3406                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3407                         $redirectArticle = WikiPage::factory( $this );
3408                         $newid = $redirectArticle->insertOn( $dbw );
3409                         if ( $newid ) { // sanity
3410                                 $redirectRevision = new Revision( array(
3411                                         'page'    => $newid,
3412                                         'comment' => $comment,
3413                                         'text'    => $redirectText ) );
3414                                 $redirectRevision->insertOn( $dbw );
3415                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3416
3417                                 wfRunHooks( 'NewRevisionFromEditComplete',
3418                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3419
3420                                 # Now, we record the link from the redirect to the new title.
3421                                 # It should have no other outgoing links...
3422                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3423                                 $dbw->insert( 'pagelinks',
3424                                         array(
3425                                                 'pl_from'      => $newid,
3426                                                 'pl_namespace' => $nt->getNamespace(),
3427                                                 'pl_title'     => $nt->getDBkey() ),
3428                                         __METHOD__ );
3429                         }
3430                 } else {
3431                         $this->resetArticleID( 0 );
3432                 }
3433
3434                 # Log the move
3435                 $logid = $logEntry->insert();
3436                 $logEntry->publish( $logid );
3437
3438                 # Purge caches for old and new titles
3439                 if ( $moveOverRedirect ) {
3440                         # A simple purge is enough when moving over a redirect
3441                         $nt->purgeSquid();
3442                 } else {
3443                         # Purge caches as per article creation, including any pages that link to this title
3444                         Article::onArticleCreate( $nt );
3445                 }
3446                 $this->purgeSquid();
3447         }
3448
3449         /**
3450          * Move this page's subpages to be subpages of $nt
3451          *
3452          * @param $nt Title Move target
3453          * @param $auth bool Whether $wgUser's permissions should be checked
3454          * @param $reason string The reason for the move
3455          * @param $createRedirect bool Whether to create redirects from the old subpages to
3456          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3457          * @return mixed array with old page titles as keys, and strings (new page titles) or
3458          *     arrays (errors) as values, or an error array with numeric indices if no pages
3459          *     were moved
3460          */
3461         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3462                 global $wgMaximumMovedPages;
3463                 // Check permissions
3464                 if ( !$this->userCan( 'move-subpages' ) ) {
3465                         return array( 'cant-move-subpages' );
3466                 }
3467                 // Do the source and target namespaces support subpages?
3468                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3469                         return array( 'namespace-nosubpages',
3470                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3471                 }
3472                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3473                         return array( 'namespace-nosubpages',
3474                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3475                 }
3476
3477                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3478                 $retval = array();
3479                 $count = 0;
3480                 foreach ( $subpages as $oldSubpage ) {
3481                         $count++;
3482                         if ( $count > $wgMaximumMovedPages ) {
3483                                 $retval[$oldSubpage->getPrefixedTitle()] =
3484                                                 array( 'movepage-max-pages',
3485                                                         $wgMaximumMovedPages );
3486                                 break;
3487                         }
3488
3489                         // We don't know whether this function was called before
3490                         // or after moving the root page, so check both
3491                         // $this and $nt
3492                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3493                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3494                         {
3495                                 // When moving a page to a subpage of itself,
3496                                 // don't move it twice
3497                                 continue;
3498                         }
3499                         $newPageName = preg_replace(
3500                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3501                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3502                                         $oldSubpage->getDBkey() );
3503                         if ( $oldSubpage->isTalkPage() ) {
3504                                 $newNs = $nt->getTalkPage()->getNamespace();
3505                         } else {
3506                                 $newNs = $nt->getSubjectPage()->getNamespace();
3507                         }
3508                         # Bug 14385: we need makeTitleSafe because the new page names may
3509                         # be longer than 255 characters.
3510                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3511
3512                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3513                         if ( $success === true ) {
3514                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3515                         } else {
3516                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3517                         }
3518                 }
3519                 return $retval;
3520         }
3521
3522         /**
3523          * Checks if this page is just a one-rev redirect.
3524          * Adds lock, so don't use just for light purposes.
3525          *
3526          * @return Bool
3527          */
3528         public function isSingleRevRedirect() {
3529                 $dbw = wfGetDB( DB_MASTER );
3530                 # Is it a redirect?
3531                 $row = $dbw->selectRow( 'page',
3532                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3533                         $this->pageCond(),
3534                         __METHOD__,
3535                         array( 'FOR UPDATE' )
3536                 );
3537                 # Cache some fields we may want
3538                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3539                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3540                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3541                 if ( !$this->mRedirect ) {
3542                         return false;
3543                 }
3544                 # Does the article have a history?
3545                 $row = $dbw->selectField( array( 'page', 'revision' ),
3546                         'rev_id',
3547                         array( 'page_namespace' => $this->getNamespace(),
3548                                 'page_title' => $this->getDBkey(),
3549                                 'page_id=rev_page',
3550                                 'page_latest != rev_id'
3551                         ),
3552                         __METHOD__,
3553                         array( 'FOR UPDATE' )
3554                 );
3555                 # Return true if there was no history
3556                 return ( $row === false );
3557         }
3558
3559         /**
3560          * Checks if $this can be moved to a given Title
3561          * - Selects for update, so don't call it unless you mean business
3562          *
3563          * @param $nt Title the new title to check
3564          * @return Bool
3565          */
3566         public function isValidMoveTarget( $nt ) {
3567                 # Is it an existing file?
3568                 if ( $nt->getNamespace() == NS_FILE ) {
3569                         $file = wfLocalFile( $nt );
3570                         if ( $file->exists() ) {
3571                                 wfDebug( __METHOD__ . ": file exists\n" );
3572                                 return false;
3573                         }
3574                 }
3575                 # Is it a redirect with no history?
3576                 if ( !$nt->isSingleRevRedirect() ) {
3577                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3578                         return false;
3579                 }
3580                 # Get the article text
3581                 $rev = Revision::newFromTitle( $nt );
3582                 if( !is_object( $rev ) ){
3583                         return false;
3584                 }
3585                 $text = $rev->getText();
3586                 # Does the redirect point to the source?
3587                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3588                 $m = array();
3589                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3590                         $redirTitle = Title::newFromText( $m[1] );
3591                         if ( !is_object( $redirTitle ) ||
3592                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3593                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3594                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3595                                 return false;
3596                         }
3597                 } else {
3598                         # Fail safe
3599                         wfDebug( __METHOD__ . ": failsafe\n" );
3600                         return false;
3601                 }
3602                 return true;
3603         }
3604
3605         /**
3606          * Can this title be added to a user's watchlist?
3607          *
3608          * @return Bool TRUE or FALSE
3609          */
3610         public function isWatchable() {
3611                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3612         }
3613
3614         /**
3615          * Get categories to which this Title belongs and return an array of
3616          * categories' names.
3617          *
3618          * @return Array of parents in the form:
3619          *        $parent => $currentarticle
3620          */
3621         public function getParentCategories() {
3622                 global $wgContLang;
3623
3624                 $data = array();
3625
3626                 $titleKey = $this->getArticleId();
3627
3628                 if ( $titleKey === 0 ) {
3629                         return $data;
3630                 }
3631
3632                 $dbr = wfGetDB( DB_SLAVE );
3633
3634                 $res = $dbr->select( 'categorylinks', '*',
3635                         array(
3636                                 'cl_from' => $titleKey,
3637                         ),
3638                         __METHOD__,
3639                         array()
3640                 );
3641
3642                 if ( $dbr->numRows( $res ) > 0 ) {
3643                         foreach ( $res as $row ) {
3644                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3645                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3646                         }
3647                 }
3648                 return $data;
3649         }
3650
3651         /**
3652          * Get a tree of parent categories
3653          *
3654          * @param $children Array with the children in the keys, to check for circular refs
3655          * @return Array Tree of parent categories
3656          */
3657         public function getParentCategoryTree( $children = array() ) {
3658                 $stack = array();
3659                 $parents = $this->getParentCategories();
3660
3661                 if ( $parents ) {
3662                         foreach ( $parents as $parent => $current ) {
3663                                 if ( array_key_exists( $parent, $children ) ) {
3664                                         # Circular reference
3665                                         $stack[$parent] = array();
3666                                 } else {
3667                                         $nt = Title::newFromText( $parent );
3668                                         if ( $nt ) {
3669                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3670                                         }
3671                                 }
3672                         }
3673                 }
3674
3675                 return $stack;
3676         }
3677
3678         /**
3679          * Get an associative array for selecting this title from
3680          * the "page" table
3681          *
3682          * @return Array suitable for the $where parameter of DB::select()
3683          */
3684         public function pageCond() {
3685                 if ( $this->mArticleID > 0 ) {
3686                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3687                         return array( 'page_id' => $this->mArticleID );
3688                 } else {
3689                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3690                 }
3691         }
3692
3693         /**
3694          * Get the revision ID of the previous revision
3695          *
3696          * @param $revId Int Revision ID. Get the revision that was before this one.
3697          * @param $flags Int Title::GAID_FOR_UPDATE
3698          * @return Int|Bool Old revision ID, or FALSE if none exists
3699          */
3700         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3701                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3702                 return $db->selectField( 'revision', 'rev_id',
3703                         array(
3704                                 'rev_page' => $this->getArticleId( $flags ),
3705                                 'rev_id < ' . intval( $revId )
3706                         ),
3707                         __METHOD__,
3708                         array( 'ORDER BY' => 'rev_id DESC' )
3709                 );
3710         }
3711
3712         /**
3713          * Get the revision ID of the next revision
3714          *
3715          * @param $revId Int Revision ID. Get the revision that was after this one.
3716          * @param $flags Int Title::GAID_FOR_UPDATE
3717          * @return Int|Bool Next revision ID, or FALSE if none exists
3718          */
3719         public function getNextRevisionID( $revId, $flags = 0 ) {
3720                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3721                 return $db->selectField( 'revision', 'rev_id',
3722                         array(
3723                                 'rev_page' => $this->getArticleId( $flags ),
3724                                 'rev_id > ' . intval( $revId )
3725                         ),
3726                         __METHOD__,
3727                         array( 'ORDER BY' => 'rev_id' )
3728                 );
3729         }
3730
3731         /**
3732          * Get the first revision of the page
3733          *
3734          * @param $flags Int Title::GAID_FOR_UPDATE
3735          * @return Revision|Null if page doesn't exist
3736          */
3737         public function getFirstRevision( $flags = 0 ) {
3738                 $pageId = $this->getArticleId( $flags );
3739                 if ( $pageId ) {
3740                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3741                         $row = $db->selectRow( 'revision', '*',
3742                                 array( 'rev_page' => $pageId ),
3743                                 __METHOD__,
3744                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3745                         );
3746                         if ( $row ) {
3747                                 return new Revision( $row );
3748                         }
3749                 }
3750                 return null;
3751         }
3752
3753         /**
3754          * Get the oldest revision timestamp of this page
3755          *
3756          * @param $flags Int Title::GAID_FOR_UPDATE
3757          * @return String: MW timestamp
3758          */
3759         public function getEarliestRevTime( $flags = 0 ) {
3760                 $rev = $this->getFirstRevision( $flags );
3761                 return $rev ? $rev->getTimestamp() : null;
3762         }
3763
3764         /**
3765          * Check if this is a new page
3766          *
3767          * @return bool
3768          */
3769         public function isNewPage() {
3770                 $dbr = wfGetDB( DB_SLAVE );
3771                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3772         }
3773
3774         /**
3775          * Get the number of revisions between the given revision.
3776          * Used for diffs and other things that really need it.
3777          *
3778          * @param $old int|Revision Old revision or rev ID (first before range)
3779          * @param $new int|Revision New revision or rev ID (first after range)
3780          * @return Int Number of revisions between these revisions.
3781          */
3782         public function countRevisionsBetween( $old, $new ) {
3783                 if ( !( $old instanceof Revision ) ) {
3784                         $old = Revision::newFromTitle( $this, (int)$old );
3785                 }
3786                 if ( !( $new instanceof Revision ) ) {
3787                         $new = Revision::newFromTitle( $this, (int)$new );
3788                 }
3789                 if ( !$old || !$new ) {
3790                         return 0; // nothing to compare
3791                 }
3792                 $dbr = wfGetDB( DB_SLAVE );
3793                 return (int)$dbr->selectField( 'revision', 'count(*)',
3794                         array(
3795                                 'rev_page' => $this->getArticleId(),
3796                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3797                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3798                         ),
3799                         __METHOD__
3800                 );
3801         }
3802
3803         /**
3804          * Get the number of authors between the given revision IDs.
3805          * Used for diffs and other things that really need it.
3806          *
3807          * @param $old int|Revision Old revision or rev ID (first before range)
3808          * @param $new int|Revision New revision or rev ID (first after range)
3809          * @param $limit Int Maximum number of authors
3810          * @return Int Number of revision authors between these revisions.
3811          */
3812         public function countAuthorsBetween( $old, $new, $limit ) {
3813                 if ( !( $old instanceof Revision ) ) {
3814                         $old = Revision::newFromTitle( $this, (int)$old );
3815                 }
3816                 if ( !( $new instanceof Revision ) ) {
3817                         $new = Revision::newFromTitle( $this, (int)$new );
3818                 }
3819                 if ( !$old || !$new ) {
3820                         return 0; // nothing to compare
3821                 }
3822                 $dbr = wfGetDB( DB_SLAVE );
3823                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3824                         array(
3825                                 'rev_page' => $this->getArticleID(),
3826                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3827                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3828                         ), __METHOD__,
3829                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3830                 );
3831                 return (int)$dbr->numRows( $res );
3832         }
3833
3834         /**
3835          * Compare with another title.
3836          *
3837          * @param $title Title
3838          * @return Bool
3839          */
3840         public function equals( Title $title ) {
3841                 // Note: === is necessary for proper matching of number-like titles.
3842                 return $this->getInterwiki() === $title->getInterwiki()
3843                         && $this->getNamespace() == $title->getNamespace()
3844                         && $this->getDBkey() === $title->getDBkey();
3845         }
3846
3847         /**
3848          * Check if this title is a subpage of another title
3849          *
3850          * @param $title Title
3851          * @return Bool
3852          */
3853         public function isSubpageOf( Title $title ) {
3854                 return $this->getInterwiki() === $title->getInterwiki()
3855                         && $this->getNamespace() == $title->getNamespace()
3856                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
3857         }
3858
3859         /**
3860          * Callback for usort() to do title sorts by (namespace, title)
3861          *
3862          * @param $a Title
3863          * @param $b Title
3864          *
3865          * @return Integer: result of string comparison, or namespace comparison
3866          */
3867         public static function compare( $a, $b ) {
3868                 if ( $a->getNamespace() == $b->getNamespace() ) {
3869                         return strcmp( $a->getText(), $b->getText() );
3870                 } else {
3871                         return $a->getNamespace() - $b->getNamespace();
3872                 }
3873         }
3874
3875         /**
3876          * Return a string representation of this title
3877          *
3878          * @return String representation of this title
3879          */
3880         public function __toString() {
3881                 return $this->getPrefixedText();
3882         }
3883
3884         /**
3885          * Check if page exists.  For historical reasons, this function simply
3886          * checks for the existence of the title in the page table, and will
3887          * thus return false for interwiki links, special pages and the like.
3888          * If you want to know if a title can be meaningfully viewed, you should
3889          * probably call the isKnown() method instead.
3890          *
3891          * @return Bool
3892          */
3893         public function exists() {
3894                 return $this->getArticleId() != 0;
3895         }
3896
3897         /**
3898          * Should links to this title be shown as potentially viewable (i.e. as
3899          * "bluelinks"), even if there's no record by this title in the page
3900          * table?
3901          *
3902          * This function is semi-deprecated for public use, as well as somewhat
3903          * misleadingly named.  You probably just want to call isKnown(), which
3904          * calls this function internally.
3905          *
3906          * (ISSUE: Most of these checks are cheap, but the file existence check
3907          * can potentially be quite expensive.  Including it here fixes a lot of
3908          * existing code, but we might want to add an optional parameter to skip
3909          * it and any other expensive checks.)
3910          *
3911          * @return Bool
3912          */
3913         public function isAlwaysKnown() {
3914                 if ( $this->mInterwiki != '' ) {
3915                         return true;  // any interwiki link might be viewable, for all we know
3916                 }
3917                 switch( $this->mNamespace ) {
3918                         case NS_MEDIA:
3919                         case NS_FILE:
3920                                 // file exists, possibly in a foreign repo
3921                                 return (bool)wfFindFile( $this );
3922                         case NS_SPECIAL:
3923                                 // valid special page
3924                                 return SpecialPageFactory::exists( $this->getDBkey() );
3925                         case NS_MAIN:
3926                                 // selflink, possibly with fragment
3927                                 return $this->mDbkeyform == '';
3928                         case NS_MEDIAWIKI:
3929                                 // known system message
3930                                 return $this->hasSourceText() !== false;
3931                         default:
3932                                 return false;
3933                 }
3934         }
3935
3936         /**
3937          * Does this title refer to a page that can (or might) be meaningfully
3938          * viewed?  In particular, this function may be used to determine if
3939          * links to the title should be rendered as "bluelinks" (as opposed to
3940          * "redlinks" to non-existent pages).
3941          *
3942          * @return Bool
3943          */
3944         public function isKnown() {
3945                 return $this->isAlwaysKnown() || $this->exists();
3946         }
3947
3948         /**
3949          * Does this page have source text?
3950          *
3951          * @return Boolean
3952          */
3953         public function hasSourceText() {
3954                 if ( $this->exists() ) {
3955                         return true;
3956                 }
3957
3958                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3959                         // If the page doesn't exist but is a known system message, default
3960                         // message content will be displayed, same for language subpages-
3961                         // Use always content language to avoid loading hundreds of languages
3962                         // to get the link color.
3963                         global $wgContLang;
3964                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3965                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
3966                         return $message->exists();
3967                 }
3968
3969                 return false;
3970         }
3971
3972         /**
3973          * Get the default message text or false if the message doesn't exist
3974          *
3975          * @return String or false
3976          */
3977         public function getDefaultMessageText() {
3978                 global $wgContLang;
3979
3980                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3981                         return false;
3982                 }
3983
3984                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3985                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3986
3987                 if ( $message->exists() ) {
3988                         return $message->plain();
3989                 } else {
3990                         return false;
3991                 }
3992         }
3993
3994         /**
3995          * Is this in a namespace that allows actual pages?
3996          *
3997          * @return Bool
3998          * @internal note -- uses hardcoded namespace index instead of constants
3999          */
4000         public function canExist() {
4001                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
4002         }
4003
4004         /**
4005          * Update page_touched timestamps and send squid purge messages for
4006          * pages linking to this title. May be sent to the job queue depending
4007          * on the number of links. Typically called on create and delete.
4008          */
4009         public function touchLinks() {
4010                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4011                 $u->doUpdate();
4012
4013                 if ( $this->getNamespace() == NS_CATEGORY ) {
4014                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4015                         $u->doUpdate();
4016                 }
4017         }
4018
4019         /**
4020          * Get the last touched timestamp
4021          *
4022          * @param $db DatabaseBase: optional db
4023          * @return String last-touched timestamp
4024          */
4025         public function getTouched( $db = null ) {
4026                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4027                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4028                 return $touched;
4029         }
4030
4031         /**
4032          * Get the timestamp when this page was updated since the user last saw it.
4033          *
4034          * @param $user User
4035          * @return String|Null
4036          */
4037         public function getNotificationTimestamp( $user = null ) {
4038                 global $wgUser, $wgShowUpdatedMarker;
4039                 // Assume current user if none given
4040                 if ( !$user ) {
4041                         $user = $wgUser;
4042                 }
4043                 // Check cache first
4044                 $uid = $user->getId();
4045                 // avoid isset here, as it'll return false for null entries
4046                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4047                         return $this->mNotificationTimestamp[$uid];
4048                 }
4049                 if ( !$uid || !$wgShowUpdatedMarker ) {
4050                         return $this->mNotificationTimestamp[$uid] = false;
4051                 }
4052                 // Don't cache too much!
4053                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4054                         $this->mNotificationTimestamp = array();
4055                 }
4056                 $dbr = wfGetDB( DB_SLAVE );
4057                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4058                         'wl_notificationtimestamp',
4059                         array( 'wl_namespace' => $this->getNamespace(),
4060                                 'wl_title' => $this->getDBkey(),
4061                                 'wl_user' => $user->getId()
4062                         ),
4063                         __METHOD__
4064                 );
4065                 return $this->mNotificationTimestamp[$uid];
4066         }
4067
4068         /**
4069          * Get the trackback URL for this page
4070          *
4071          * @return String Trackback URL
4072          */
4073         public function trackbackURL() {
4074                 global $wgScriptPath, $wgServer, $wgScriptExtension;
4075
4076                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
4077                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
4078         }
4079
4080         /**
4081          * Get the trackback RDF for this page
4082          *
4083          * @return String Trackback RDF
4084          */
4085         public function trackbackRDF() {
4086                 $url = htmlspecialchars( $this->getFullURL() );
4087                 $title = htmlspecialchars( $this->getText() );
4088                 $tburl = $this->trackbackURL();
4089
4090                 // Autodiscovery RDF is placed in comments so HTML validator
4091                 // won't barf. This is a rather icky workaround, but seems
4092                 // frequently used by this kind of RDF thingy.
4093                 //
4094                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4095                 return "<!--
4096 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4097                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4098                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4099 <rdf:Description
4100    rdf:about=\"$url\"
4101    dc:identifier=\"$url\"
4102    dc:title=\"$title\"
4103    trackback:ping=\"$tburl\" />
4104 </rdf:RDF>
4105 -->";
4106         }
4107
4108         /**
4109          * Generate strings used for xml 'id' names in monobook tabs
4110          *
4111          * @param $prepend string defaults to 'nstab-'
4112          * @return String XML 'id' name
4113          */
4114         public function getNamespaceKey( $prepend = 'nstab-' ) {
4115                 global $wgContLang;
4116                 // Gets the subject namespace if this title
4117                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4118                 // Checks if cononical namespace name exists for namespace
4119                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4120                         // Uses canonical namespace name
4121                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4122                 } else {
4123                         // Uses text of namespace
4124                         $namespaceKey = $this->getSubjectNsText();
4125                 }
4126                 // Makes namespace key lowercase
4127                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4128                 // Uses main
4129                 if ( $namespaceKey == '' ) {
4130                         $namespaceKey = 'main';
4131                 }
4132                 // Changes file to image for backwards compatibility
4133                 if ( $namespaceKey == 'file' ) {
4134                         $namespaceKey = 'image';
4135                 }
4136                 return $prepend . $namespaceKey;
4137         }
4138
4139         /**
4140          * Returns true if this is a special page.
4141          *
4142          * @return boolean
4143          */
4144         public function isSpecialPage() {
4145                 return $this->getNamespace() == NS_SPECIAL;
4146         }
4147
4148         /**
4149          * Returns true if this title resolves to the named special page
4150          *
4151          * @param $name String The special page name
4152          * @return boolean
4153          */
4154         public function isSpecial( $name ) {
4155                 if ( $this->getNamespace() == NS_SPECIAL ) {
4156                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4157                         if ( $name == $thisName ) {
4158                                 return true;
4159                         }
4160                 }
4161                 return false;
4162         }
4163
4164         /**
4165          * If the Title refers to a special page alias which is not the local default, resolve
4166          * the alias, and localise the name as necessary.  Otherwise, return $this
4167          *
4168          * @return Title
4169          */
4170         public function fixSpecialName() {
4171                 if ( $this->getNamespace() == NS_SPECIAL ) {
4172                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4173                         if ( $canonicalName ) {
4174                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
4175                                 if ( $localName != $this->mDbkeyform ) {
4176                                         return Title::makeTitle( NS_SPECIAL, $localName );
4177                                 }
4178                         }
4179                 }
4180                 return $this;
4181         }
4182
4183         /**
4184          * Is this Title in a namespace which contains content?
4185          * In other words, is this a content page, for the purposes of calculating
4186          * statistics, etc?
4187          *
4188          * @return Boolean
4189          */
4190         public function isContentPage() {
4191                 return MWNamespace::isContent( $this->getNamespace() );
4192         }
4193
4194         /**
4195          * Get all extant redirects to this Title
4196          *
4197          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4198          * @return Array of Title redirects to this title
4199          */
4200         public function getRedirectsHere( $ns = null ) {
4201                 $redirs = array();
4202
4203                 $dbr = wfGetDB( DB_SLAVE );
4204                 $where = array(
4205                         'rd_namespace' => $this->getNamespace(),
4206                         'rd_title' => $this->getDBkey(),
4207                         'rd_from = page_id'
4208                 );
4209                 if ( !is_null( $ns ) ) {
4210                         $where['page_namespace'] = $ns;
4211                 }
4212
4213                 $res = $dbr->select(
4214                         array( 'redirect', 'page' ),
4215                         array( 'page_namespace', 'page_title' ),
4216                         $where,
4217                         __METHOD__
4218                 );
4219
4220                 foreach ( $res as $row ) {
4221                         $redirs[] = self::newFromRow( $row );
4222                 }
4223                 return $redirs;
4224         }
4225
4226         /**
4227          * Check if this Title is a valid redirect target
4228          *
4229          * @return Bool
4230          */
4231         public function isValidRedirectTarget() {
4232                 global $wgInvalidRedirectTargets;
4233
4234                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4235                 if ( $this->isSpecial( 'Userlogout' ) ) {
4236                         return false;
4237                 }
4238
4239                 foreach ( $wgInvalidRedirectTargets as $target ) {
4240                         if ( $this->isSpecial( $target ) ) {
4241                                 return false;
4242                         }
4243                 }
4244
4245                 return true;
4246         }
4247
4248         /**
4249          * Get a backlink cache object
4250          *
4251          * @return object BacklinkCache
4252          */
4253         function getBacklinkCache() {
4254                 if ( is_null( $this->mBacklinkCache ) ) {
4255                         $this->mBacklinkCache = new BacklinkCache( $this );
4256                 }
4257                 return $this->mBacklinkCache;
4258         }
4259
4260         /**
4261          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4262          *
4263          * @return Boolean
4264          */
4265         public function canUseNoindex() {
4266                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4267
4268                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4269                         ? $wgContentNamespaces
4270                         : $wgExemptFromUserRobotsControl;
4271
4272                 return !in_array( $this->mNamespace, $bannedNamespaces );
4273
4274         }
4275
4276         /**
4277          * Returns restriction types for the current Title
4278          *
4279          * @return array applicable restriction types
4280          */
4281         public function getRestrictionTypes() {
4282                 if ( $this->getNamespace() == NS_SPECIAL ) {
4283                         return array();
4284                 }
4285
4286                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4287
4288                 if ( $this->getNamespace() != NS_FILE ) {
4289                         # Remove the upload restriction for non-file titles
4290                         $types = array_diff( $types, array( 'upload' ) );
4291                 }
4292
4293                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4294
4295                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4296                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4297
4298                 return $types;
4299         }
4300         /**
4301          * Get a filtered list of all restriction types supported by this wiki.
4302          * @param bool $exists True to get all restriction types that apply to
4303          * titles that do exist, False for all restriction types that apply to
4304          * titles that do not exist
4305          * @return array
4306          */
4307         public static function getFilteredRestrictionTypes( $exists = true ) {
4308                 global $wgRestrictionTypes;
4309                 $types = $wgRestrictionTypes;
4310                 if ( $exists ) {
4311                         # Remove the create restriction for existing titles
4312                         $types = array_diff( $types, array( 'create' ) );
4313                 } else {
4314                         # Only the create and upload restrictions apply to non-existing titles
4315                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4316                 }
4317                 return $types;
4318         }
4319
4320         /**
4321          * Returns the raw sort key to be used for categories, with the specified
4322          * prefix.  This will be fed to Collation::getSortKey() to get a
4323          * binary sortkey that can be used for actual sorting.
4324          *
4325          * @param $prefix string The prefix to be used, specified using
4326          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4327          *   prefix.
4328          * @return string
4329          */
4330         public function getCategorySortkey( $prefix = '' ) {
4331                 $unprefixed = $this->getText();
4332
4333                 // Anything that uses this hook should only depend
4334                 // on the Title object passed in, and should probably
4335                 // tell the users to run updateCollations.php --force
4336                 // in order to re-sort existing category relations.
4337                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4338                 if ( $prefix !== '' ) {
4339                         # Separate with a line feed, so the unprefixed part is only used as
4340                         # a tiebreaker when two pages have the exact same prefix.
4341                         # In UCA, tab is the only character that can sort above LF
4342                         # so we strip both of them from the original prefix.
4343                         $prefix = strtr( $prefix, "\n\t", '  ' );
4344                         return "$prefix\n$unprefixed";
4345                 }
4346                 return $unprefixed;
4347         }
4348
4349         /**
4350          * Get the language in which the content of this page is written.
4351          * Defaults to $wgContLang, but in certain cases it can be e.g.
4352          * $wgLang (such as special pages, which are in the user language).
4353          *
4354          * @since 1.18
4355          * @return object Language
4356          */
4357         public function getPageLanguage() {
4358                 global $wgLang;
4359                 if ( $this->getNamespace() == NS_SPECIAL ) {
4360                         // special pages are in the user language
4361                         return $wgLang;
4362                 } elseif ( $this->isCssOrJsPage() ) {
4363                         // css/js should always be LTR and is, in fact, English
4364                         return wfGetLangObj( 'en' );
4365                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4366                         // Parse mediawiki messages with correct target language
4367                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4368                         return wfGetLangObj( $lang );
4369                 }
4370                 global $wgContLang;
4371                 // If nothing special, it should be in the wiki content language
4372                 $pageLang = $wgContLang;
4373                 // Hook at the end because we don't want to override the above stuff
4374                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4375                 return wfGetLangObj( $pageLang );
4376         }
4377 }