includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Represents a title within MediaWiki.
  25  * Optionally may contain an interwiki designation or namespace.
  26  * @note This class can fetch various kinds of data from the database;
  27  *       however, it does so inefficiently.
  28  *
  29  * @internal documentation reviewed 15 Mar 2010
  30  */
  31 class Title {
  32         /** @name Static cache variables */
  33         // @{
  34         static private $titleCache = array();
  35         // @}
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50
  51         /**
  52          * @name Private member variables
  53          * Please use the accessor functions instead.
  54          * @private
  55          */
  56         // @{
  57
  58         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  59         var $mUrlform = '';               // /< URL-encoded form of the main part
  60         var $mDbkeyform = '';             // /< Main part with underscores
  61         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  62         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  63         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  64         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  65         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  66         var $mLatestID = false;           // /< ID of most recent revision
  67         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  68         var $mOldRestrictions = false;
  69         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  70         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  71         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  72         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  73         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  74         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  75         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  76         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  77         # Don't change the following default, NS_MAIN is hardcoded in several
  78         # places.  See bug 696.
  79         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  80                                                                           # Zero except in {{transclusion}} tags
  81         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  82         var $mLength = -1;                // /< The page length, 0 for special pages
  83         var $mRedirect = null;            // /< Is the article at this title a redirect?
  84         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  85         var $mBacklinkCache = null;       // /< Cache of links to this title
  86         // @}
  87
  88
  89         /**
  90          * Constructor
  91          */
  92         /*protected*/ function __construct() { }
  93
  94         /**
  95          * Create a new Title from a prefixed DB key
  96          *
  97          * @param $key String the database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return Title, or NULL on an error
 101          */
 102         public static function newFromDBkey( $key ) {
 103                 $t = new Title();
 104                 $t->mDbkeyform = $key;
 105                 if ( $t->secureAndSplit() ) {
 106                         return $t;
 107                 } else {
 108                         return null;
 109                 }
 110         }
 111
 112         /**
 113          * Create a new Title from text, such as what one would find in a link. De-
 114          * codes any HTML entities in the text.
 115          *
 116          * @param $text String the link text; spaces, prefixes, and an
 117          *   initial ':' indicating the main namespace are accepted.
 118          * @param $defaultNamespace Int the namespace to use if none is speci-
 119          *   fied by a prefix.  If you want to force a specific namespace even if
 120          *   $text might begin with a namespace prefix, use makeTitle() or
 121          *   makeTitleSafe().
 122          * @return Title, or null on an error.
 123          */
 124         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 125                 if ( is_object( $text ) ) {
 126                         throw new MWException( 'Title::newFromText given an object' );
 127                 }
 128
 129                 /**
 130                  * Wiki pages often contain multiple links to the same page.
 131                  * Title normalization and parsing can become expensive on
 132                  * pages with many links, so we can save a little time by
 133                  * caching them.
 134                  *
 135                  * In theory these are value objects and won't get changed...
 136                  */
 137                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 138                         return Title::$titleCache[$text];
 139                 }
 140
 141                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 142                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 143
 144                 $t = new Title();
 145                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 146                 $t->mDefaultNamespace = $defaultNamespace;
 147
 148                 static $cachedcount = 0 ;
 149                 if ( $t->secureAndSplit() ) {
 150                         if ( $defaultNamespace == NS_MAIN ) {
 151                                 if ( $cachedcount >= self::CACHE_MAX ) {
 152                                         # Avoid memory leaks on mass operations...
 153                                         Title::$titleCache = array();
 154                                         $cachedcount = 0;
 155                                 }
 156                                 $cachedcount++;
 157                                 Title::$titleCache[$text] =& $t;
 158                         }
 159                         return $t;
 160                 } else {
 161                         $ret = null;
 162                         return $ret;
 163                 }
 164         }
 165
 166         /**
 167          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 168          *
 169          * Example of wrong and broken code:
 170          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 171          *
 172          * Example of right code:
 173          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Create a new Title from URL-encoded text. Ensures that
 176          * the given title's length does not exceed the maximum.
 177          *
 178          * @param $url String the title, as might be taken from a URL
 179          * @return Title the new object, or NULL on an error
 180          */
 181         public static function newFromURL( $url ) {
 182                 global $wgLegalTitleChars;
 183                 $t = new Title();
 184
 185                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 186                 # but some URLs used it as a space replacement and they still come
 187                 # from some external search tools.
 188                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 189                         $url = str_replace( '+', ' ', $url );
 190                 }
 191
 192                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 193                 if ( $t->secureAndSplit() ) {
 194                         return $t;
 195                 } else {
 196                         return null;
 197                 }
 198         }
 199
 200         /**
 201          * Create a new Title from an article ID
 202          *
 203          * @param $id Int the page_id corresponding to the Title to create
 204          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 205          * @return Title the new object, or NULL on an error
 206          */
 207         public static function newFromID( $id, $flags = 0 ) {
 208                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 209                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 210                 if ( $row !== false ) {
 211                         $title = Title::newFromRow( $row );
 212                 } else {
 213                         $title = null;
 214                 }
 215                 return $title;
 216         }
 217
 218         /**
 219          * Make an array of titles from an array of IDs
 220          *
 221          * @param $ids Array of Int Array of IDs
 222          * @return Array of Titles
 223          */
 224         public static function newFromIDs( $ids ) {
 225                 if ( !count( $ids ) ) {
 226                         return array();
 227                 }
 228                 $dbr = wfGetDB( DB_SLAVE );
 229
 230                 $res = $dbr->select(
 231                         'page',
 232                         array(
 233                                 'page_namespace', 'page_title', 'page_id',
 234                                 'page_len', 'page_is_redirect', 'page_latest',
 235                         ),
 236                         array( 'page_id' => $ids ),
 237                         __METHOD__
 238                 );
 239
 240                 $titles = array();
 241                 foreach ( $res as $row ) {
 242                         $titles[] = Title::newFromRow( $row );
 243                 }
 244                 return $titles;
 245         }
 246
 247         /**
 248          * Make a Title object from a DB row
 249          *
 250          * @param $row Object database row (needs at least page_title,page_namespace)
 251          * @return Title corresponding Title
 252          */
 253         public static function newFromRow( $row ) {
 254                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 255                 $t->loadFromRow( $row );
 256                 return $t;
 257         }
 258
 259         /**
 260          * Load Title object fields from a DB row.
 261          * If false is given, the title will be treated as non-existing.
 262          *
 263          * @param $row Object|false database row
 264          * @return void
 265          */
 266         public function loadFromRow( $row ) {
 267                 if ( $row ) { // page found
 268                         if ( isset( $row->page_id ) )
 269                                 $this->mArticleID = (int)$row->page_id;
 270                         if ( isset( $row->page_len ) )
 271                                 $this->mLength = (int)$row->page_len;
 272                         if ( isset( $row->page_is_redirect ) )
 273                                 $this->mRedirect = (bool)$row->page_is_redirect;
 274                         if ( isset( $row->page_latest ) )
 275                                 $this->mLatestID = (int)$row->page_latest;
 276                 } else { // page not found
 277                         $this->mArticleID = 0;
 278                         $this->mLength = 0;
 279                         $this->mRedirect = false;
 280                         $this->mLatestID = 0;
 281                 }
 282         }
 283
 284         /**
 285          * Create a new Title from a namespace index and a DB key.
 286          * It's assumed that $ns and $title are *valid*, for instance when
 287          * they came directly from the database or a special page name.
 288          * For convenience, spaces are converted to underscores so that
 289          * eg user_text fields can be used directly.
 290          *
 291          * @param $ns Int the namespace of the article
 292          * @param $title String the unprefixed database key form
 293          * @param $fragment String the link fragment (after the "#")
 294          * @param $interwiki String the interwiki prefix
 295          * @return Title the new object
 296          */
 297         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 298                 $t = new Title();
 299                 $t->mInterwiki = $interwiki;
 300                 $t->mFragment = $fragment;
 301                 $t->mNamespace = $ns = intval( $ns );
 302                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 303                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 304                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 305                 $t->mTextform = str_replace( '_', ' ', $title );
 306                 return $t;
 307         }
 308
 309         /**
 310          * Create a new Title from a namespace index and a DB key.
 311          * The parameters will be checked for validity, which is a bit slower
 312          * than makeTitle() but safer for user-provided data.
 313          *
 314          * @param $ns Int the namespace of the article
 315          * @param $title String database key form
 316          * @param $fragment String the link fragment (after the "#")
 317          * @param $interwiki String interwiki prefix
 318          * @return Title the new object, or NULL on an error
 319          */
 320         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 321                 $t = new Title();
 322                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 323                 if ( $t->secureAndSplit() ) {
 324                         return $t;
 325                 } else {
 326                         return null;
 327                 }
 328         }
 329
 330         /**
 331          * Create a new Title for the Main Page
 332          *
 333          * @return Title the new object
 334          */
 335         public static function newMainPage() {
 336                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 337                 // Don't give fatal errors if the message is broken
 338                 if ( !$title ) {
 339                         $title = Title::newFromText( 'Main Page' );
 340                 }
 341                 return $title;
 342         }
 343
 344         /**
 345          * Extract a redirect destination from a string and return the
 346          * Title, or null if the text doesn't contain a valid redirect
 347          * This will only return the very next target, useful for
 348          * the redirect table and other checks that don't need full recursion
 349          *
 350          * @param $text String: Text with possible redirect
 351          * @return Title: The corresponding Title
 352          */
 353         public static function newFromRedirect( $text ) {
 354                 return self::newFromRedirectInternal( $text );
 355         }
 356
 357         /**
 358          * Extract a redirect destination from a string and return the
 359          * Title, or null if the text doesn't contain a valid redirect
 360          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 361          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 362          *
 363          * @param $text String Text with possible redirect
 364          * @return Title
 365          */
 366         public static function newFromRedirectRecurse( $text ) {
 367                 $titles = self::newFromRedirectArray( $text );
 368                 return $titles ? array_pop( $titles ) : null;
 369         }
 370
 371         /**
 372          * Extract a redirect destination from a string and return an
 373          * array of Titles, or null if the text doesn't contain a valid redirect
 374          * The last element in the array is the final destination after all redirects
 375          * have been resolved (up to $wgMaxRedirects times)
 376          *
 377          * @param $text String Text with possible redirect
 378          * @return Array of Titles, with the destination last
 379          */
 380         public static function newFromRedirectArray( $text ) {
 381                 global $wgMaxRedirects;
 382                 $title = self::newFromRedirectInternal( $text );
 383                 if ( is_null( $title ) ) {
 384                         return null;
 385                 }
 386                 // recursive check to follow double redirects
 387                 $recurse = $wgMaxRedirects;
 388                 $titles = array( $title );
 389                 while ( --$recurse > 0 ) {
 390                         if ( $title->isRedirect() ) {
 391                                 $article = new Article( $title, 0 );
 392                                 $newtitle = $article->getRedirectTarget();
 393                         } else {
 394                                 break;
 395                         }
 396                         // Redirects to some special pages are not permitted
 397                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 398                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 399                                 $title = $newtitle;
 400                                 $titles[] = $newtitle;
 401                         } else {
 402                                 break;
 403                         }
 404                 }
 405                 return $titles;
 406         }
 407
 408         /**
 409          * Really extract the redirect destination
 410          * Do not call this function directly, use one of the newFromRedirect* functions above
 411          *
 412          * @param $text String Text with possible redirect
 413          * @return Title
 414          */
 415         protected static function newFromRedirectInternal( $text ) {
 416                 global $wgMaxRedirects;
 417                 if ( $wgMaxRedirects < 1 ) {
 418                         //redirects are disabled, so quit early
 419                         return null;
 420                 }
 421                 $redir = MagicWord::get( 'redirect' );
 422                 $text = trim( $text );
 423                 if ( $redir->matchStartAndRemove( $text ) ) {
 424                         // Extract the first link and see if it's usable
 425                         // Ensure that it really does come directly after #REDIRECT
 426                         // Some older redirects included a colon, so don't freak about that!
 427                         $m = array();
 428                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 429                                 // Strip preceding colon used to "escape" categories, etc.
 430                                 // and URL-decode links
 431                                 if ( strpos( $m[1], '%' ) !== false ) {
 432                                         // Match behavior of inline link parsing here;
 433                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 434                                 }
 435                                 $title = Title::newFromText( $m[1] );
 436                                 // If the title is a redirect to bad special pages or is invalid, return null
 437                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 438                                         return null;
 439                                 }
 440                                 return $title;
 441                         }
 442                 }
 443                 return null;
 444         }
 445
 446 # ----------------------------------------------------------------------------
 447 #       Static functions
 448 # ----------------------------------------------------------------------------
 449
 450         /**
 451          * Get the prefixed DB key associated with an ID
 452          *
 453          * @param $id Int the page_id of the article
 454          * @return Title an object representing the article, or NULL if no such article was found
 455          */
 456         public static function nameOf( $id ) {
 457                 $dbr = wfGetDB( DB_SLAVE );
 458
 459                 $s = $dbr->selectRow(
 460                         'page',
 461                         array( 'page_namespace', 'page_title' ),
 462                         array( 'page_id' => $id ),
 463                         __METHOD__
 464                 );
 465                 if ( $s === false ) {
 466                         return null;
 467                 }
 468
 469                 $n = self::makeName( $s->page_namespace, $s->page_title );
 470                 return $n;
 471         }
 472
 473         /**
 474          * Get a regex character class describing the legal characters in a link
 475          *
 476          * @return String the list of characters, not delimited
 477          */
 478         public static function legalChars() {
 479                 global $wgLegalTitleChars;
 480                 return $wgLegalTitleChars;
 481         }
 482
 483         /**
 484          * Get a string representation of a title suitable for
 485          * including in a search index
 486          *
 487          * @param $ns Int a namespace index
 488          * @param $title String text-form main part
 489          * @return String a stripped-down title string ready for the search index
 490          */
 491         public static function indexTitle( $ns, $title ) {
 492                 global $wgContLang;
 493
 494                 $lc = SearchEngine::legalSearchChars() . '&#;';
 495                 $t = $wgContLang->normalizeForSearch( $title );
 496                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 497                 $t = $wgContLang->lc( $t );
 498
 499                 # Handle 's, s'
 500                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 501                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 502
 503                 $t = preg_replace( "/\\s+/", ' ', $t );
 504
 505                 if ( $ns == NS_FILE ) {
 506                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 507                 }
 508                 return trim( $t );
 509         }
 510
 511         /**
 512          * Make a prefixed DB key from a DB key and a namespace index
 513          *
 514          * @param $ns Int numerical representation of the namespace
 515          * @param $title String the DB key form the title
 516          * @param $fragment String The link fragment (after the "#")
 517          * @param $interwiki String The interwiki prefix
 518          * @return String the prefixed form of the title
 519          */
 520         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 521                 global $wgContLang;
 522
 523                 $namespace = $wgContLang->getNsText( $ns );
 524                 $name = $namespace == '' ? $title : "$namespace:$title";
 525                 if ( strval( $interwiki ) != '' ) {
 526                         $name = "$interwiki:$name";
 527                 }
 528                 if ( strval( $fragment ) != '' ) {
 529                         $name .= '#' . $fragment;
 530                 }
 531                 return $name;
 532         }
 533
 534         /**
 535          * Determine whether the object refers to a page within
 536          * this project.
 537          *
 538          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 539          */
 540         public function isLocal() {
 541                 if ( $this->mInterwiki != '' ) {
 542                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 543                 } else {
 544                         return true;
 545                 }
 546         }
 547
 548         /**
 549          * Determine whether the object refers to a page within
 550          * this project and is transcludable.
 551          *
 552          * @return Bool TRUE if this is transcludable
 553          */
 554         public function isTrans() {
 555                 if ( $this->mInterwiki == '' ) {
 556                         return false;
 557                 }
 558
 559                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 560         }
 561
 562         /**
 563          * Returns the DB name of the distant wiki which owns the object.
 564          *
 565          * @return String the DB name
 566          */
 567         public function getTransWikiID() {
 568                 if ( $this->mInterwiki == '' ) {
 569                         return false;
 570                 }
 571
 572                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 573         }
 574
 575         /**
 576          * Escape a text fragment, say from a link, for a URL
 577          *
 578          * @param $fragment string containing a URL or link fragment (after the "#")
 579          * @return String: escaped string
 580          */
 581         static function escapeFragmentForURL( $fragment ) {
 582                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 583                 # fragments appear not to work in IE (at least up to 7) or in at least
 584                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 585                 # to care if they aren't encoded.
 586                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 587         }
 588
 589 # ----------------------------------------------------------------------------
 590 #       Other stuff
 591 # ----------------------------------------------------------------------------
 592
 593         /** Simple accessors */
 594         /**
 595          * Get the text form (spaces not underscores) of the main part
 596          *
 597          * @return String Main part of the title
 598          */
 599         public function getText() { return $this->mTextform; }
 600
 601         /**
 602          * Get the URL-encoded form of the main part
 603          *
 604          * @return String Main part of the title, URL-encoded
 605          */
 606         public function getPartialURL() { return $this->mUrlform; }
 607
 608         /**
 609          * Get the main part with underscores
 610          *
 611          * @return String: Main part of the title, with underscores
 612          */
 613         public function getDBkey() { return $this->mDbkeyform; }
 614
 615         /**
 616          * Get the namespace index, i.e. one of the NS_xxxx constants.
 617          *
 618          * @return Integer: Namespace index
 619          */
 620         public function getNamespace() { return $this->mNamespace; }
 621
 622         /**
 623          * Get the namespace text
 624          *
 625          * @return String: Namespace text
 626          */
 627         public function getNsText() {
 628                 global $wgContLang;
 629
 630                 if ( $this->mInterwiki != '' ) {
 631                         // This probably shouldn't even happen. ohh man, oh yuck.
 632                         // But for interwiki transclusion it sometimes does.
 633                         // Shit. Shit shit shit.
 634                         //
 635                         // Use the canonical namespaces if possible to try to
 636                         // resolve a foreign namespace.
 637                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 638                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 639                         }
 640                 }
 641
 642                 if ( $wgContLang->needsGenderDistinction() &&
 643                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 644                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 645                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 646                 }
 647
 648                 return $wgContLang->getNsText( $this->mNamespace );
 649         }
 650
 651         /**
 652          * Get the DB key with the initial letter case as specified by the user
 653          *
 654          * @return String DB key
 655          */
 656         function getUserCaseDBKey() {
 657                 return $this->mUserCaseDBKey;
 658         }
 659
 660         /**
 661          * Get the namespace text of the subject (rather than talk) page
 662          *
 663          * @return String Namespace text
 664          */
 665         public function getSubjectNsText() {
 666                 global $wgContLang;
 667                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 668         }
 669
 670         /**
 671          * Get the namespace text of the talk page
 672          *
 673          * @return String Namespace text
 674          */
 675         public function getTalkNsText() {
 676                 global $wgContLang;
 677                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 678         }
 679
 680         /**
 681          * Could this title have a corresponding talk page?
 682          *
 683          * @return Bool TRUE or FALSE
 684          */
 685         public function canTalk() {
 686                 return( MWNamespace::canTalk( $this->mNamespace ) );
 687         }
 688
 689         /**
 690          * Get the interwiki prefix (or null string)
 691          *
 692          * @return String Interwiki prefix
 693          */
 694         public function getInterwiki() { return $this->mInterwiki; }
 695
 696         /**
 697          * Get the Title fragment (i.e.\ the bit after the #) in text form
 698          *
 699          * @return String Title fragment
 700          */
 701         public function getFragment() { return $this->mFragment; }
 702
 703         /**
 704          * Get the fragment in URL form, including the "#" character if there is one
 705          * @return String Fragment in URL form
 706          */
 707         public function getFragmentForURL() {
 708                 if ( $this->mFragment == '' ) {
 709                         return '';
 710                 } else {
 711                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 712                 }
 713         }
 714
 715         /**
 716          * Get the default namespace index, for when there is no namespace
 717          *
 718          * @return Int Default namespace index
 719          */
 720         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 721
 722         /**
 723          * Get title for search index
 724          *
 725          * @return String a stripped-down title string ready for the
 726          *  search index
 727          */
 728         public function getIndexTitle() {
 729                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 730         }
 731
 732         /**
 733          * Get the prefixed database key form
 734          *
 735          * @return String the prefixed title, with underscores and
 736          *  any interwiki and namespace prefixes
 737          */
 738         public function getPrefixedDBkey() {
 739                 $s = $this->prefix( $this->mDbkeyform );
 740                 $s = str_replace( ' ', '_', $s );
 741                 return $s;
 742         }
 743
 744         /**
 745          * Get the prefixed title with spaces.
 746          * This is the form usually used for display
 747          *
 748          * @return String the prefixed title, with spaces
 749          */
 750         public function getPrefixedText() {
 751                 // @todo FIXME: Bad usage of empty() ?
 752                 if ( empty( $this->mPrefixedText ) ) {
 753                         $s = $this->prefix( $this->mTextform );
 754                         $s = str_replace( '_', ' ', $s );
 755                         $this->mPrefixedText = $s;
 756                 }
 757                 return $this->mPrefixedText;
 758         }
 759
 760         /**
 761          * Get the prefixed title with spaces, plus any fragment
 762          * (part beginning with '#')
 763          *
 764          * @return String the prefixed title, with spaces and the fragment, including '#'
 765          */
 766         public function getFullText() {
 767                 $text = $this->getPrefixedText();
 768                 if ( $this->mFragment != '' ) {
 769                         $text .= '#' . $this->mFragment;
 770                 }
 771                 return $text;
 772         }
 773
 774         /**
 775          * Get the base page name, i.e. the leftmost part before any slashes
 776          *
 777          * @return String Base name
 778          */
 779         public function getBaseText() {
 780                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 781                         return $this->getText();
 782                 }
 783
 784                 $parts = explode( '/', $this->getText() );
 785                 # Don't discard the real title if there's no subpage involved
 786                 if ( count( $parts ) > 1 ) {
 787                         unset( $parts[count( $parts ) - 1] );
 788                 }
 789                 return implode( '/', $parts );
 790         }
 791
 792         /**
 793          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
 794          *
 795          * @return String Subpage name
 796          */
 797         public function getSubpageText() {
 798                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 799                         return( $this->mTextform );
 800                 }
 801                 $parts = explode( '/', $this->mTextform );
 802                 return( $parts[count( $parts ) - 1] );
 803         }
 804
 805         /**
 806          * Get a URL-encoded form of the subpage text
 807          *
 808          * @return String URL-encoded subpage name
 809          */
 810         public function getSubpageUrlForm() {
 811                 $text = $this->getSubpageText();
 812                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 813                 return( $text );
 814         }
 815
 816         /**
 817          * Get a URL-encoded title (not an actual URL) including interwiki
 818          *
 819          * @return String the URL-encoded form
 820          */
 821         public function getPrefixedURL() {
 822                 $s = $this->prefix( $this->mDbkeyform );
 823                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 824                 return $s;
 825         }
 826
 827         /**
 828          * Get a real URL referring to this title, with interwiki link and
 829          * fragment
 830          *
 831          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 832          *   links. Can be specified as an associative array as well, e.g.,
 833          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 834          * @param $variant String language variant of url (for sr, zh..)
 835          * @return String the URL
 836          */
 837         public function getFullURL( $query = '', $variant = false ) {
 838                 global $wgServer, $wgRequest;
 839
 840                 if ( is_array( $query ) ) {
 841                         $query = wfArrayToCGI( $query );
 842                 }
 843
 844                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 845                 if ( !$interwiki ) {
 846                         $url = $this->getLocalURL( $query, $variant );
 847
 848                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 849                         // Correct fix would be to move the prepending elsewhere.
 850                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 851                                 $url = $wgServer . $url;
 852                         }
 853                 } else {
 854                         $namespace = $this->getNsText();
 855                         if ( $namespace != '' ) {
 856                                 # Can this actually happen? Interwikis shouldn't be parsed.
 857                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 858                                 $namespace .= ':';
 859                         }
 860                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 861                         $url = wfAppendQuery( $url, $query );
 862                 }
 863
 864                 # Finally, add the fragment.
 865                 $url .= $this->getFragmentForURL();
 866
 867                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 868                 return $url;
 869         }
 870
 871         /**
 872          * Get a URL with no fragment or server name.  If this page is generated
 873          * with action=render, $wgServer is prepended.
 874          *
 875          * @param $query Mixed: an optional query string; if not specified,
 876          *   $wgArticlePath will be used.  Can be specified as an associative array
 877          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 878          *   URL-escaped).
 879          * @param $variant String language variant of url (for sr, zh..)
 880          * @return String the URL
 881          */
 882         public function getLocalURL( $query = '', $variant = false ) {
 883                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 884                 global $wgVariantArticlePath, $wgContLang;
 885
 886                 if ( is_array( $query ) ) {
 887                         $query = wfArrayToCGI( $query );
 888                 }
 889
 890                 if ( $this->isExternal() ) {
 891                         $url = $this->getFullURL();
 892                         if ( $query ) {
 893                                 // This is currently only used for edit section links in the
 894                                 // context of interwiki transclusion. In theory we should
 895                                 // append the query to the end of any existing query string,
 896                                 // but interwiki transclusion is already broken in that case.
 897                                 $url .= "?$query";
 898                         }
 899                 } else {
 900                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 901                         if ( $query == '' ) {
 902                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 903                                         if ( !$wgVariantArticlePath ) {
 904                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 905                                         } else {
 906                                                 $variantArticlePath = $wgVariantArticlePath;
 907                                         }
 908                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 909                                         $url = str_replace( '$1', $dbkey, $url  );
 910                                 } else {
 911                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 912                                 }
 913                         } else {
 914                                 global $wgActionPaths;
 915                                 $url = false;
 916                                 $matches = array();
 917                                 if ( !empty( $wgActionPaths ) &&
 918                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 919                                 {
 920                                         $action = urldecode( $matches[2] );
 921                                         if ( isset( $wgActionPaths[$action] ) ) {
 922                                                 $query = $matches[1];
 923                                                 if ( isset( $matches[4] ) ) {
 924                                                         $query .= $matches[4];
 925                                                 }
 926                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 927                                                 if ( $query != '' ) {
 928                                                         $url = wfAppendQuery( $url, $query );
 929                                                 }
 930                                         }
 931                                 }
 932
 933                                 if ( $url === false ) {
 934                                         if ( $query == '-' ) {
 935                                                 $query = '';
 936                                         }
 937                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 938                                 }
 939                         }
 940
 941                         // @todo FIXME: This causes breakage in various places when we
 942                         // actually expected a local URL and end up with dupe prefixes.
 943                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 944                                 $url = $wgServer . $url;
 945                         }
 946                 }
 947                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 948                 return $url;
 949         }
 950
 951         /**
 952          * Get a URL that's the simplest URL that will be valid to link, locally,
 953          * to the current Title.  It includes the fragment, but does not include
 954          * the server unless action=render is used (or the link is external).  If
 955          * there's a fragment but the prefixed text is empty, we just return a link
 956          * to the fragment.
 957          *
 958          * The result obviously should not be URL-escaped, but does need to be
 959          * HTML-escaped if it's being output in HTML.
 960          *
 961          * @param $query Array of Strings An associative array of key => value pairs for the
 962          *   query string.  Keys and values will be escaped.
 963          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 964          *   for external links.  Default is "false" (same variant as current page,
 965          *   for anonymous users).
 966          * @return String the URL
 967          */
 968         public function getLinkUrl( $query = array(), $variant = false ) {
 969                 wfProfileIn( __METHOD__ );
 970                 if ( $this->isExternal() ) {
 971                         $ret = $this->getFullURL( $query );
 972                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 973                         $ret = $this->getFragmentForURL();
 974                 } else {
 975                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 976                 }
 977                 wfProfileOut( __METHOD__ );
 978                 return $ret;
 979         }
 980
 981         /**
 982          * Get an HTML-escaped version of the URL form, suitable for
 983          * using in a link, without a server name or fragment
 984          *
 985          * @param $query String an optional query string
 986          * @return String the URL
 987          */
 988         public function escapeLocalURL( $query = '' ) {
 989                 return htmlspecialchars( $this->getLocalURL( $query ) );
 990         }
 991
 992         /**
 993          * Get an HTML-escaped version of the URL form, suitable for
 994          * using in a link, including the server name and fragment
 995          *
 996          * @param $query String an optional query string
 997          * @return String the URL
 998          */
 999         public function escapeFullURL( $query = '' ) {
1000                 return htmlspecialchars( $this->getFullURL( $query ) );
1001         }
1002
1003         /**
1004          * Get the URL form for an internal link.
1005          * - Used in various Squid-related code, in case we have a different
1006          * internal hostname for the server from the exposed one.
1007          *
1008          * @param $query String an optional query string
1009          * @param $variant String language variant of url (for sr, zh..)
1010          * @return String the URL
1011          */
1012         public function getInternalURL( $query = '', $variant = false ) {
1013                 global $wgInternalServer, $wgServer;
1014                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1015                 $url = $server . $this->getLocalURL( $query, $variant );
1016                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1017                 return $url;
1018         }
1019
1020         /**
1021          * Get the edit URL for this Title
1022          *
1023          * @return String the URL, or a null string if this is an
1024          *  interwiki link
1025          */
1026         public function getEditURL() {
1027                 if ( $this->mInterwiki != '' ) {
1028                         return '';
1029                 }
1030                 $s = $this->getLocalURL( 'action=edit' );
1031
1032                 return $s;
1033         }
1034
1035         /**
1036          * Get the HTML-escaped displayable text form.
1037          * Used for the title field in <a> tags.
1038          *
1039          * @return String the text, including any prefixes
1040          */
1041         public function getEscapedText() {
1042                 return htmlspecialchars( $this->getPrefixedText() );
1043         }
1044
1045         /**
1046          * Is this Title interwiki?
1047          *
1048          * @return Bool
1049          */
1050         public function isExternal() {
1051                 return ( $this->mInterwiki != '' );
1052         }
1053
1054         /**
1055          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1056          *
1057          * @param $action String Action to check (default: edit)
1058          * @return Bool
1059          */
1060         public function isSemiProtected( $action = 'edit' ) {
1061                 if ( $this->exists() ) {
1062                         $restrictions = $this->getRestrictions( $action );
1063                         if ( count( $restrictions ) > 0 ) {
1064                                 foreach ( $restrictions as $restriction ) {
1065                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1066                                                 return false;
1067                                         }
1068                                 }
1069                         } else {
1070                                 # Not protected
1071                                 return false;
1072                         }
1073                         return true;
1074                 } else {
1075                         # If it doesn't exist, it can't be protected
1076                         return false;
1077                 }
1078         }
1079
1080         /**
1081          * Does the title correspond to a protected article?
1082          *
1083          * @param $action String the action the page is protected from,
1084          * by default checks all actions.
1085          * @return Bool
1086          */
1087         public function isProtected( $action = '' ) {
1088                 global $wgRestrictionLevels;
1089
1090                 $restrictionTypes = $this->getRestrictionTypes();
1091
1092                 # Special pages have inherent protection
1093                 if( $this->getNamespace() == NS_SPECIAL ) {
1094                         return true;
1095                 }
1096
1097                 # Check regular protection levels
1098                 foreach ( $restrictionTypes as $type ) {
1099                         if ( $action == $type || $action == '' ) {
1100                                 $r = $this->getRestrictions( $type );
1101                                 foreach ( $wgRestrictionLevels as $level ) {
1102                                         if ( in_array( $level, $r ) && $level != '' ) {
1103                                                 return true;
1104                                         }
1105                                 }
1106                         }
1107                 }
1108
1109                 return false;
1110         }
1111
1112         /**
1113          * Is this a conversion table for the LanguageConverter?
1114          *
1115          * @return Bool
1116          */
1117         public function isConversionTable() {
1118                 if(
1119                         $this->getNamespace() == NS_MEDIAWIKI &&
1120                         strpos( $this->getText(), 'Conversiontable' ) !== false
1121                 )
1122                 {
1123                         return true;
1124                 }
1125
1126                 return false;
1127         }
1128
1129         /**
1130          * Is $wgUser watching this page?
1131          *
1132          * @return Bool
1133          */
1134         public function userIsWatching() {
1135                 global $wgUser;
1136
1137                 if ( is_null( $this->mWatched ) ) {
1138                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1139                                 $this->mWatched = false;
1140                         } else {
1141                                 $this->mWatched = $wgUser->isWatched( $this );
1142                         }
1143                 }
1144                 return $this->mWatched;
1145         }
1146
1147         /**
1148          * Can $wgUser perform $action on this page?
1149          * This skips potentially expensive cascading permission checks
1150          * as well as avoids expensive error formatting
1151          *
1152          * Suitable for use for nonessential UI controls in common cases, but
1153          * _not_ for functional access control.
1154          *
1155          * May provide false positives, but should never provide a false negative.
1156          *
1157          * @param $action String action that permission needs to be checked for
1158          * @return Bool
1159          */
1160         public function quickUserCan( $action ) {
1161                 return $this->userCan( $action, false );
1162         }
1163
1164         /**
1165          * Determines if $user is unable to edit this page because it has been protected
1166          * by $wgNamespaceProtection.
1167          *
1168          * @param $user User object to check permissions
1169          * @return Bool
1170          */
1171         public function isNamespaceProtected( User $user ) {
1172                 global $wgNamespaceProtection;
1173
1174                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1175                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1176                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1177                                         return true;
1178                                 }
1179                         }
1180                 }
1181                 return false;
1182         }
1183
1184         /**
1185          * Can $wgUser perform $action on this page?
1186          *
1187          * @param $action String action that permission needs to be checked for
1188          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1189          * @return Bool
1190          */
1191         public function userCan( $action, $doExpensiveQueries = true ) {
1192                 global $wgUser;
1193                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1194         }
1195
1196         /**
1197          * Can $user perform $action on this page?
1198          *
1199          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1200          *
1201          * @param $action String action that permission needs to be checked for
1202          * @param $user User to check
1203          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1204          *   skipping checks for cascading protections and user blocks.
1205          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1206          * @return Array of arguments to wfMsg to explain permissions problems.
1207          */
1208         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1209                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1210
1211                 // Remove the errors being ignored.
1212                 foreach ( $errors as $index => $error ) {
1213                         $error_key = is_array( $error ) ? $error[0] : $error;
1214
1215                         if ( in_array( $error_key, $ignoreErrors ) ) {
1216                                 unset( $errors[$index] );
1217                         }
1218                 }
1219
1220                 return $errors;
1221         }
1222
1223         /**
1224          * Permissions checks that fail most often, and which are easiest to test.
1225          *
1226          * @param $action String the action to check
1227          * @param $user User user to check
1228          * @param $errors Array list of current errors
1229          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1230          * @param $short Boolean short circuit on first error
1231          *
1232          * @return Array list of errors
1233          */
1234         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1235                 $ns = $this->getNamespace();
1236
1237                 if ( $action == 'create' ) {
1238                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1239                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1240                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1241                         }
1242                 } elseif ( $action == 'move' ) {
1243                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1244                                         && $ns == NS_USER && !$this->isSubpage() ) {
1245                                 // Show user page-specific message only if the user can move other pages
1246                                 $errors[] = array( 'cant-move-user-page' );
1247                         }
1248
1249                         // Check if user is allowed to move files if it's a file
1250                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1251                                 $errors[] = array( 'movenotallowedfile' );
1252                         }
1253
1254                         if ( !$user->isAllowed( 'move', $ns) ) {
1255                                 // User can't move anything
1256
1257                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1258                                         array( 'user' ), $ns ), true );
1259                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1260                                         array( 'autoconfirmed' ), $ns ), true );
1261
1262                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1263                                         // custom message if logged-in users without any special rights can move
1264                                         $errors[] = array( 'movenologintext' );
1265                                 } else {
1266                                         $errors[] = array( 'movenotallowed' );
1267                                 }
1268                         }
1269                 } elseif ( $action == 'move-target' ) {
1270                         if ( !$user->isAllowed( 'move', $ns ) ) {
1271                                 // User can't move anything
1272                                 $errors[] = array( 'movenotallowed' );
1273                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1274                                         && $ns == NS_USER && !$this->isSubpage() ) {
1275                                 // Show user page-specific message only if the user can move other pages
1276                                 $errors[] = array( 'cant-move-to-user-page' );
1277                         }
1278                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1279                         // We avoid expensive display logic for quickUserCan's and such
1280                         $groups = false;
1281                         if ( !$short ) {
1282                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1283                                         User::getGroupsWithPermission( $action, $ns ) );
1284                         }
1285
1286                         if ( $groups ) {
1287                                 global $wgLang;
1288                                 $return = array(
1289                                         'badaccess-groups',
1290                                         $wgLang->commaList( $groups ),
1291                                         count( $groups )
1292                                 );
1293                         } else {
1294                                 $return = array( 'badaccess-group0' );
1295                         }
1296                         $errors[] = $return;
1297                 }
1298
1299                 return $errors;
1300         }
1301
1302         /**
1303          * Add the resulting error code to the errors array
1304          *
1305          * @param $errors Array list of current errors
1306          * @param $result Mixed result of errors
1307          *
1308          * @return Array list of errors
1309          */
1310         private function resultToError( $errors, $result ) {
1311                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1312                         // A single array representing an error
1313                         $errors[] = $result;
1314                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1315                         // A nested array representing multiple errors
1316                         $errors = array_merge( $errors, $result );
1317                 } elseif ( $result !== '' && is_string( $result ) ) {
1318                         // A string representing a message-id
1319                         $errors[] = array( $result );
1320                 } elseif ( $result === false ) {
1321                         // a generic "We don't want them to do that"
1322                         $errors[] = array( 'badaccess-group0' );
1323                 }
1324                 return $errors;
1325         }
1326
1327         /**
1328          * Check various permission hooks
1329          *
1330          * @param $action String the action to check
1331          * @param $user User user to check
1332          * @param $errors Array list of current errors
1333          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1334          * @param $short Boolean short circuit on first error
1335          *
1336          * @return Array list of errors
1337          */
1338         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1339                 // Use getUserPermissionsErrors instead
1340                 $result = '';
1341                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1342                         return $result ? array() : array( array( 'badaccess-group0' ) );
1343                 }
1344                 // Check getUserPermissionsErrors hook
1345                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1346                         $errors = $this->resultToError( $errors, $result );
1347                 }
1348                 // Check getUserPermissionsErrorsExpensive hook
1349                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1350                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1351                         $errors = $this->resultToError( $errors, $result );
1352                 }
1353
1354                 return $errors;
1355         }
1356
1357         /**
1358          * Check permissions on special pages & namespaces
1359          *
1360          * @param $action String the action to check
1361          * @param $user User user to check
1362          * @param $errors Array list of current errors
1363          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1364          * @param $short Boolean short circuit on first error
1365          *
1366          * @return Array list of errors
1367          */
1368         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1369                 # Only 'createaccount' and 'execute' can be performed on
1370                 # special pages, which don't actually exist in the DB.
1371                 $specialOKActions = array( 'createaccount', 'execute' );
1372                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1373                         $errors[] = array( 'ns-specialprotected' );
1374                 }
1375
1376                 # Check $wgNamespaceProtection for restricted namespaces
1377                 if ( $this->isNamespaceProtected( $user ) ) {
1378                         $ns = $this->mNamespace == NS_MAIN ?
1379                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1380                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1381                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1382                 }
1383
1384                 return $errors;
1385         }
1386
1387         /**
1388          * Check CSS/JS sub-page permissions
1389          *
1390          * @param $action String the action to check
1391          * @param $user User user to check
1392          * @param $errors Array list of current errors
1393          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1394          * @param $short Boolean short circuit on first error
1395          *
1396          * @return Array list of errors
1397          */
1398         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1399                 # Protect css/js subpages of user pages
1400                 # XXX: this might be better using restrictions
1401                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1402                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1403                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1404                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1405                                 $errors[] = array( 'customcssprotected' );
1406                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1407                                 $errors[] = array( 'customjsprotected' );
1408                         }
1409                 }
1410
1411                 return $errors;
1412         }
1413
1414         /**
1415          * Check against page_restrictions table requirements on this
1416          * page. The user must possess all required rights for this
1417          * action.
1418          *
1419          * @param $action String the action to check
1420          * @param $user User user to check
1421          * @param $errors Array list of current errors
1422          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1423          * @param $short Boolean short circuit on first error
1424          *
1425          * @return Array list of errors
1426          */
1427         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1428                 foreach ( $this->getRestrictions( $action ) as $right ) {
1429                         // Backwards compatibility, rewrite sysop -> protect
1430                         if ( $right == 'sysop' ) {
1431                                 $right = 'protect';
1432                         }
1433                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1434                                 // Users with 'editprotected' permission can edit protected pages
1435                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected', $this->mNamespace ) ) {
1436                                         // Users with 'editprotected' permission cannot edit protected pages
1437                                         // with cascading option turned on.
1438                                         if ( $this->mCascadeRestriction ) {
1439                                                 $errors[] = array( 'protectedpagetext', $right );
1440                                         }
1441                                 } else {
1442                                         $errors[] = array( 'protectedpagetext', $right );
1443                                 }
1444                         }
1445                 }
1446
1447                 return $errors;
1448         }
1449
1450         /**
1451          * Check restrictions on cascading pages.
1452          *
1453          * @param $action String the action to check
1454          * @param $user User to check
1455          * @param $errors Array list of current errors
1456          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1457          * @param $short Boolean short circuit on first error
1458          *
1459          * @return Array list of errors
1460          */
1461         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1462                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1463                         # We /could/ use the protection level on the source page, but it's
1464                         # fairly ugly as we have to establish a precedence hierarchy for pages
1465                         # included by multiple cascade-protected pages. So just restrict
1466                         # it to people with 'protect' permission, as they could remove the
1467                         # protection anyway.
1468                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1469                         # Cascading protection depends on more than this page...
1470                         # Several cascading protected pages may include this page...
1471                         # Check each cascading level
1472                         # This is only for protection restrictions, not for all actions
1473                         if ( isset( $restrictions[$action] ) ) {
1474                                 foreach ( $restrictions[$action] as $right ) {
1475                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1476                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1477                                                 $pages = '';
1478                                                 foreach ( $cascadingSources as $page )
1479                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1480                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1481                                         }
1482                                 }
1483                         }
1484                 }
1485
1486                 return $errors;
1487         }
1488
1489         /**
1490          * Check action permissions not already checked in checkQuickPermissions
1491          *
1492          * @param $action String the action to check
1493          * @param $user User to check
1494          * @param $errors Array list of current errors
1495          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1496          * @param $short Boolean short circuit on first error
1497          *
1498          * @return Array list of errors
1499          */
1500         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1501                 if ( $action == 'protect' ) {
1502                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1503                                 // If they can't edit, they shouldn't protect.
1504                                 $errors[] = array( 'protect-cantedit' );
1505                         }
1506                 } elseif ( $action == 'create' ) {
1507                         $title_protection = $this->getTitleProtection();
1508                         if( $title_protection ) {
1509                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1510                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1511                                 }
1512                                 if( $title_protection['pt_create_perm'] == '' ||
1513                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1514                                                 $this->mNamespace ) ) {
1515                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1516                                 }
1517                         }
1518                 } elseif ( $action == 'move' ) {
1519                         // Check for immobile pages
1520                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1521                                 // Specific message for this case
1522                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1523                         } elseif ( !$this->isMovable() ) {
1524                                 // Less specific message for rarer cases
1525                                 $errors[] = array( 'immobile-page' );
1526                         }
1527                 } elseif ( $action == 'move-target' ) {
1528                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1529                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1530                         } elseif ( !$this->isMovable() ) {
1531                                 $errors[] = array( 'immobile-target-page' );
1532                         }
1533                 }
1534                 return $errors;
1535         }
1536
1537         /**
1538          * Check that the user isn't blocked from editting.
1539          *
1540          * @param $action String the action to check
1541          * @param $user User to check
1542          * @param $errors Array list of current errors
1543          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1544          * @param $short Boolean short circuit on first error
1545          *
1546          * @return Array list of errors
1547          */
1548         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1549                 if( !$doExpensiveQueries ) {
1550                         return $errors;
1551                 }
1552
1553                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1554
1555                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1556                         $errors[] = array( 'confirmedittext' );
1557                 }
1558
1559                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1560                         // Edit blocks should not affect reading.
1561                         // Account creation blocks handled at userlogin.
1562                         // Unblocking handled in SpecialUnblock
1563                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1564                         // Don't block the user from editing their own talk page unless they've been
1565                         // explicitly blocked from that too.
1566                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1567                         $block = $user->mBlock;
1568
1569                         // This is from OutputPage::blockedPage
1570                         // Copied at r23888 by werdna
1571
1572                         $id = $user->blockedBy();
1573                         $reason = $user->blockedFor();
1574                         if ( $reason == '' ) {
1575                                 $reason = wfMsg( 'blockednoreason' );
1576                         }
1577                         $ip = wfGetIP();
1578
1579                         if ( is_numeric( $id ) ) {
1580                                 $name = User::whoIs( $id );
1581                         } else {
1582                                 $name = $id;
1583                         }
1584
1585                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1586                         $blockid = $block->getId();
1587                         $blockExpiry = $user->mBlock->mExpiry;
1588                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1589                         if ( $blockExpiry == 'infinity' ) {
1590                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1591                         } else {
1592                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1593                         }
1594
1595                         $intended = strval( $user->mBlock->getTarget() );
1596
1597                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1598                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1599                 }
1600
1601                 return $errors;
1602         }
1603
1604         /**
1605          * Can $user perform $action on this page? This is an internal function,
1606          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1607          * checks on wfReadOnly() and blocks)
1608          *
1609          * @param $action String action that permission needs to be checked for
1610          * @param $user User to check
1611          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1612          * @param $short Bool Set this to true to stop after the first permission error.
1613          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1614          */
1615         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1616                 wfProfileIn( __METHOD__ );
1617
1618                 $errors = array();
1619                 $checks = array(
1620                         'checkQuickPermissions',
1621                         'checkPermissionHooks',
1622                         'checkSpecialsAndNSPermissions',
1623                         'checkCSSandJSPermissions',
1624                         'checkPageRestrictions',
1625                         'checkCascadingSourcesRestrictions',
1626                         'checkActionPermissions',
1627                         'checkUserBlock'
1628                 );
1629
1630                 while( count( $checks ) > 0 &&
1631                            !( $short && count( $errors ) > 0 ) ) {
1632                         $method = array_shift( $checks );
1633                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1634                 }
1635
1636                 wfProfileOut( __METHOD__ );
1637                 return $errors;
1638         }
1639
1640         /**
1641          * Is this title subject to title protection?
1642          * Title protection is the one applied against creation of such title.
1643          *
1644          * @return Mixed An associative array representing any existent title
1645          *   protection, or false if there's none.
1646          */
1647         private function getTitleProtection() {
1648                 // Can't protect pages in special namespaces
1649                 if ( $this->getNamespace() < 0 ) {
1650                         return false;
1651                 }
1652
1653                 // Can't protect pages that exist.
1654                 if ( $this->exists() ) {
1655                         return false;
1656                 }
1657
1658                 if ( !isset( $this->mTitleProtection ) ) {
1659                         $dbr = wfGetDB( DB_SLAVE );
1660                         $res = $dbr->select( 'protected_titles', '*',
1661                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1662                                 __METHOD__ );
1663
1664                         // fetchRow returns false if there are no rows.
1665                         $this->mTitleProtection = $dbr->fetchRow( $res );
1666                 }
1667                 return $this->mTitleProtection;
1668         }
1669
1670         /**
1671          * Update the title protection status
1672          *
1673          * @param $create_perm String Permission required for creation
1674          * @param $reason String Reason for protection
1675          * @param $expiry String Expiry timestamp
1676          * @return boolean true
1677          */
1678         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1679                 global $wgUser, $wgContLang;
1680
1681                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1682                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1683                         // No change
1684                         return true;
1685                 }
1686
1687                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1688
1689                 $dbw = wfGetDB( DB_MASTER );
1690
1691                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1692
1693                 $expiry_description = '';
1694                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1695                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1696                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1697                 } else {
1698                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1699                 }
1700
1701                 # Update protection table
1702                 if ( $create_perm != '' ) {
1703                         $this->mTitleProtection = array(
1704                                         'pt_namespace' => $namespace,
1705                                         'pt_title' => $title,
1706                                         'pt_create_perm' => $create_perm,
1707                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1708                                         'pt_expiry' => $encodedExpiry,
1709                                         'pt_user' => $wgUser->getId(),
1710                                         'pt_reason' => $reason,
1711                                 );
1712                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1713                                 $this->mTitleProtection, __METHOD__     );
1714                 } else {
1715                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1716                                 'pt_title' => $title ), __METHOD__ );
1717                         $this->mTitleProtection = false;
1718                 }
1719
1720                 # Update the protection log
1721                 if ( $dbw->affectedRows() ) {
1722                         $log = new LogPage( 'protect' );
1723
1724                         if ( $create_perm ) {
1725                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1726                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1727                         } else {
1728                                 $log->addEntry( 'unprotect', $this, $reason );
1729                         }
1730                 }
1731
1732                 return true;
1733         }
1734
1735         /**
1736          * Remove any title protection due to page existing
1737          */
1738         public function deleteTitleProtection() {
1739                 $dbw = wfGetDB( DB_MASTER );
1740
1741                 $dbw->delete(
1742                         'protected_titles',
1743                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1744                         __METHOD__
1745                 );
1746                 $this->mTitleProtection = false;
1747         }
1748
1749         /**
1750          * Would anybody with sufficient privileges be able to move this page?
1751          * Some pages just aren't movable.
1752          *
1753          * @return Bool TRUE or FALSE
1754          */
1755         public function isMovable() {
1756                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1757         }
1758
1759         /**
1760          * Can $wgUser read this page?
1761          *
1762          * @return Bool
1763          * @todo fold these checks into userCan()
1764          */
1765         public function userCanRead() {
1766                 global $wgUser, $wgGroupPermissions;
1767
1768                 static $useShortcut = null;
1769
1770                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1771                 if ( is_null( $useShortcut ) ) {
1772                         global $wgRevokePermissions;
1773                         $useShortcut = true;
1774                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1775                                 # Not a public wiki, so no shortcut
1776                                 $useShortcut = false;
1777                         } elseif ( !empty( $wgRevokePermissions ) ) {
1778                                 /**
1779                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1780                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1781                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1782                                  * reading is allowed.
1783                                  */
1784                                 foreach ( $wgRevokePermissions as $perms ) {
1785                                         if ( !empty( $perms['read'] ) ) {
1786                                                 # We might be removing the read right from the user, so no shortcut
1787                                                 $useShortcut = false;
1788                                                 break;
1789                                         }
1790                                 }
1791                         }
1792                 }
1793
1794                 $result = null;
1795                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1796                 if ( $result !== null ) {
1797                         return $result;
1798                 }
1799
1800                 # Shortcut for public wikis, allows skipping quite a bit of code
1801                 if ( $useShortcut ) {
1802                         return true;
1803                 }
1804
1805                 if ( $wgUser->isAllowed( 'read' ) ) {
1806                         return true;
1807                 } else {
1808                         global $wgWhitelistRead;
1809
1810                         # Always grant access to the login page.
1811                         # Even anons need to be able to log in.
1812                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1813                                 return true;
1814                         }
1815
1816                         # Bail out if there isn't whitelist
1817                         if ( !is_array( $wgWhitelistRead ) ) {
1818                                 return false;
1819                         }
1820
1821                         # Check for explicit whitelisting
1822                         $name = $this->getPrefixedText();
1823                         $dbName = $this->getPrefixedDBKey();
1824                         // Check with and without underscores
1825                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1826                                 return true;
1827
1828                         # Old settings might have the title prefixed with
1829                         # a colon for main-namespace pages
1830                         if ( $this->getNamespace() == NS_MAIN ) {
1831                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1832                                         return true;
1833                                 }
1834                         }
1835
1836                         # If it's a special page, ditch the subpage bit and check again
1837                         if ( $this->getNamespace() == NS_SPECIAL ) {
1838                                 $name = $this->getDBkey();
1839                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1840                                 if ( $name === false ) {
1841                                         # Invalid special page, but we show standard login required message
1842                                         return false;
1843                                 }
1844
1845                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1846                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1847                                         return true;
1848                                 }
1849                         }
1850
1851                 }
1852                 return false;
1853         }
1854
1855         /**
1856          * Is this the mainpage?
1857          * @note Title::newFromText seams to be sufficiently optimized by the title
1858          * cache that we don't need to over-optimize by doing direct comparisons and
1859          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1860          * ends up reporting something differently than $title->isMainPage();
1861          *
1862          * @return Bool
1863          */
1864         public function isMainPage() {
1865                 return $this->equals( Title::newMainPage() );
1866         }
1867
1868         /**
1869          * Is this a talk page of some sort?
1870          *
1871          * @return Bool
1872          */
1873         public function isTalkPage() {
1874                 return MWNamespace::isTalk( $this->getNamespace() );
1875         }
1876
1877         /**
1878          * Is this a subpage?
1879          *
1880          * @return Bool
1881          */
1882         public function isSubpage() {
1883                 return MWNamespace::hasSubpages( $this->mNamespace )
1884                         ? strpos( $this->getText(), '/' ) !== false
1885                         : false;
1886         }
1887
1888         /**
1889          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1890          *
1891          * @return Bool
1892          */
1893         public function hasSubpages() {
1894                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1895                         # Duh
1896                         return false;
1897                 }
1898
1899                 # We dynamically add a member variable for the purpose of this method
1900                 # alone to cache the result.  There's no point in having it hanging
1901                 # around uninitialized in every Title object; therefore we only add it
1902                 # if needed and don't declare it statically.
1903                 if ( isset( $this->mHasSubpages ) ) {
1904                         return $this->mHasSubpages;
1905                 }
1906
1907                 $subpages = $this->getSubpages( 1 );
1908                 if ( $subpages instanceof TitleArray ) {
1909                         return $this->mHasSubpages = (bool)$subpages->count();
1910                 }
1911                 return $this->mHasSubpages = false;
1912         }
1913
1914         /**
1915          * Get all subpages of this page.
1916          *
1917          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1918          * @return mixed TitleArray, or empty array if this page's namespace
1919          *  doesn't allow subpages
1920          */
1921         public function getSubpages( $limit = -1 ) {
1922                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1923                         return array();
1924                 }
1925
1926                 $dbr = wfGetDB( DB_SLAVE );
1927                 $conds['page_namespace'] = $this->getNamespace();
1928                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1929                 $options = array();
1930                 if ( $limit > -1 ) {
1931                         $options['LIMIT'] = $limit;
1932                 }
1933                 return $this->mSubpages = TitleArray::newFromResult(
1934                         $dbr->select( 'page',
1935                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1936                                 $conds,
1937                                 __METHOD__,
1938                                 $options
1939                         )
1940                 );
1941         }
1942
1943         /**
1944          * Does that page contain wikitext, or it is JS, CSS or whatever?
1945          *
1946          * @return Bool
1947          */
1948         public function isWikitextPage() {
1949                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
1950                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
1951                 return $retval;
1952         }
1953
1954         /**
1955          * Could this page contain custom CSS or JavaScript, based
1956          * on the title?
1957          *
1958          * @return Bool
1959          */
1960         public function isCssOrJsPage() {
1961                 $retval = $this->mNamespace == NS_MEDIAWIKI
1962                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1963                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
1964                 return $retval;
1965         }
1966
1967         /**
1968          * Is this a .css or .js subpage of a user page?
1969          * @return Bool
1970          */
1971         public function isCssJsSubpage() {
1972                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1973         }
1974
1975         /**
1976          * Is this a *valid* .css or .js subpage of a user page?
1977          *
1978          * @return Bool
1979          * @deprecated since 1.17
1980          */
1981         public function isValidCssJsSubpage() {
1982                 return $this->isCssJsSubpage();
1983         }
1984
1985         /**
1986          * Trim down a .css or .js subpage title to get the corresponding skin name
1987          *
1988          * @return string containing skin name from .css or .js subpage title
1989          */
1990         public function getSkinFromCssJsSubpage() {
1991                 $subpage = explode( '/', $this->mTextform );
1992                 $subpage = $subpage[ count( $subpage ) - 1 ];
1993                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1994         }
1995
1996         /**
1997          * Is this a .css subpage of a user page?
1998          *
1999          * @return Bool
2000          */
2001         public function isCssSubpage() {
2002                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2003         }
2004
2005         /**
2006          * Is this a .js subpage of a user page?
2007          *
2008          * @return Bool
2009          */
2010         public function isJsSubpage() {
2011                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2012         }
2013
2014         /**
2015          * Protect css subpages of user pages: can $wgUser edit
2016          * this page?
2017          *
2018          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2019          * @return Bool
2020          */
2021         public function userCanEditCssSubpage() {
2022                 global $wgUser;
2023                 wfDeprecated( __METHOD__ );
2024                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2025                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2026         }
2027
2028         /**
2029          * Protect js subpages of user pages: can $wgUser edit
2030          * this page?
2031          *
2032          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2033          * @return Bool
2034          */
2035         public function userCanEditJsSubpage() {
2036                 global $wgUser;
2037                 wfDeprecated( __METHOD__ );
2038                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2039                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2040         }
2041
2042         /**
2043          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2044          *
2045          * @return Bool If the page is subject to cascading restrictions.
2046          */
2047         public function isCascadeProtected() {
2048                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2049                 return ( $sources > 0 );
2050         }
2051
2052         /**
2053          * Cascading protection: Get the source of any cascading restrictions on this page.
2054          *
2055          * @param $getPages Bool Whether or not to retrieve the actual pages
2056          *        that the restrictions have come from.
2057          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2058          *     have come, false for none, or true if such restrictions exist, but $getPages
2059          *     was not set.  The restriction array is an array of each type, each of which
2060          *     contains a array of unique groups.
2061          */
2062         public function getCascadeProtectionSources( $getPages = true ) {
2063                 global $wgContLang;
2064                 $pagerestrictions = array();
2065
2066                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2067                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2068                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2069                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2070                 }
2071
2072                 wfProfileIn( __METHOD__ );
2073
2074                 $dbr = wfGetDB( DB_SLAVE );
2075
2076                 if ( $this->getNamespace() == NS_FILE ) {
2077                         $tables = array( 'imagelinks', 'page_restrictions' );
2078                         $where_clauses = array(
2079                                 'il_to' => $this->getDBkey(),
2080                                 'il_from=pr_page',
2081                                 'pr_cascade' => 1
2082                         );
2083                 } else {
2084                         $tables = array( 'templatelinks', 'page_restrictions' );
2085                         $where_clauses = array(
2086                                 'tl_namespace' => $this->getNamespace(),
2087                                 'tl_title' => $this->getDBkey(),
2088                                 'tl_from=pr_page',
2089                                 'pr_cascade' => 1
2090                         );
2091                 }
2092
2093                 if ( $getPages ) {
2094                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2095                                                    'pr_expiry', 'pr_type', 'pr_level' );
2096                         $where_clauses[] = 'page_id=pr_page';
2097                         $tables[] = 'page';
2098                 } else {
2099                         $cols = array( 'pr_expiry' );
2100                 }
2101
2102                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2103
2104                 $sources = $getPages ? array() : false;
2105                 $now = wfTimestampNow();
2106                 $purgeExpired = false;
2107
2108                 foreach ( $res as $row ) {
2109                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2110                         if ( $expiry > $now ) {
2111                                 if ( $getPages ) {
2112                                         $page_id = $row->pr_page;
2113                                         $page_ns = $row->page_namespace;
2114                                         $page_title = $row->page_title;
2115                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2116                                         # Add groups needed for each restriction type if its not already there
2117                                         # Make sure this restriction type still exists
2118
2119                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2120                                                 $pagerestrictions[$row->pr_type] = array();
2121                                         }
2122
2123                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2124                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2125                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2126                                         }
2127                                 } else {
2128                                         $sources = true;
2129                                 }
2130                         } else {
2131                                 // Trigger lazy purge of expired restrictions from the db
2132                                 $purgeExpired = true;
2133                         }
2134                 }
2135                 if ( $purgeExpired ) {
2136                         Title::purgeExpiredRestrictions();
2137                 }
2138
2139                 if ( $getPages ) {
2140                         $this->mCascadeSources = $sources;
2141                         $this->mCascadingRestrictions = $pagerestrictions;
2142                 } else {
2143                         $this->mHasCascadingRestrictions = $sources;
2144                 }
2145
2146                 wfProfileOut( __METHOD__ );
2147                 return array( $sources, $pagerestrictions );
2148         }
2149
2150         /**
2151          * Returns cascading restrictions for the current article
2152          *
2153          * @return Boolean
2154          */
2155         function areRestrictionsCascading() {
2156                 if ( !$this->mRestrictionsLoaded ) {
2157                         $this->loadRestrictions();
2158                 }
2159
2160                 return $this->mCascadeRestriction;
2161         }
2162
2163         /**
2164          * Loads a string into mRestrictions array
2165          *
2166          * @param $res Resource restrictions as an SQL result.
2167          * @param $oldFashionedRestrictions String comma-separated list of page
2168          *        restrictions from page table (pre 1.10)
2169          */
2170         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2171                 $rows = array();
2172
2173                 foreach ( $res as $row ) {
2174                         $rows[] = $row;
2175                 }
2176
2177                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2178         }
2179
2180         /**
2181          * Compiles list of active page restrictions from both page table (pre 1.10)
2182          * and page_restrictions table for this existing page.
2183          * Public for usage by LiquidThreads.
2184          *
2185          * @param $rows array of db result objects
2186          * @param $oldFashionedRestrictions string comma-separated list of page
2187          *        restrictions from page table (pre 1.10)
2188          */
2189         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2190                 global $wgContLang;
2191                 $dbr = wfGetDB( DB_SLAVE );
2192
2193                 $restrictionTypes = $this->getRestrictionTypes();
2194
2195                 foreach ( $restrictionTypes as $type ) {
2196                         $this->mRestrictions[$type] = array();
2197                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2198                 }
2199
2200                 $this->mCascadeRestriction = false;
2201
2202                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2203
2204                 if ( $oldFashionedRestrictions === null ) {
2205                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2206                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2207                 }
2208
2209                 if ( $oldFashionedRestrictions != '' ) {
2210
2211                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2212                                 $temp = explode( '=', trim( $restrict ) );
2213                                 if ( count( $temp ) == 1 ) {
2214                                         // old old format should be treated as edit/move restriction
2215                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2216                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2217                                 } else {
2218                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2219                                 }
2220                         }
2221
2222                         $this->mOldRestrictions = true;
2223
2224                 }
2225
2226                 if ( count( $rows ) ) {
2227                         # Current system - load second to make them override.
2228                         $now = wfTimestampNow();
2229                         $purgeExpired = false;
2230
2231                         # Cycle through all the restrictions.
2232                         foreach ( $rows as $row ) {
2233
2234                                 // Don't take care of restrictions types that aren't allowed
2235                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2236                                         continue;
2237
2238                                 // This code should be refactored, now that it's being used more generally,
2239                                 // But I don't really see any harm in leaving it in Block for now -werdna
2240                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2241
2242                                 // Only apply the restrictions if they haven't expired!
2243                                 if ( !$expiry || $expiry > $now ) {
2244                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2245                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2246
2247                                         $this->mCascadeRestriction |= $row->pr_cascade;
2248                                 } else {
2249                                         // Trigger a lazy purge of expired restrictions
2250                                         $purgeExpired = true;
2251                                 }
2252                         }
2253
2254                         if ( $purgeExpired ) {
2255                                 Title::purgeExpiredRestrictions();
2256                         }
2257                 }
2258
2259                 $this->mRestrictionsLoaded = true;
2260         }
2261
2262         /**
2263          * Load restrictions from the page_restrictions table
2264          *
2265          * @param $oldFashionedRestrictions String comma-separated list of page
2266          *        restrictions from page table (pre 1.10)
2267          */
2268         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2269                 global $wgContLang;
2270                 if ( !$this->mRestrictionsLoaded ) {
2271                         if ( $this->exists() ) {
2272                                 $dbr = wfGetDB( DB_SLAVE );
2273
2274                                 $res = $dbr->select(
2275                                         'page_restrictions',
2276                                         '*',
2277                                         array( 'pr_page' => $this->getArticleId() ),
2278                                         __METHOD__
2279                                 );
2280
2281                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2282                         } else {
2283                                 $title_protection = $this->getTitleProtection();
2284
2285                                 if ( $title_protection ) {
2286                                         $now = wfTimestampNow();
2287                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2288
2289                                         if ( !$expiry || $expiry > $now ) {
2290                                                 // Apply the restrictions
2291                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2292                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2293                                         } else { // Get rid of the old restrictions
2294                                                 Title::purgeExpiredRestrictions();
2295                                                 $this->mTitleProtection = false;
2296                                         }
2297                                 } else {
2298                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2299                                 }
2300                                 $this->mRestrictionsLoaded = true;
2301                         }
2302                 }
2303         }
2304
2305         /**
2306          * Purge expired restrictions from the page_restrictions table
2307          */
2308         static function purgeExpiredRestrictions() {
2309                 $dbw = wfGetDB( DB_MASTER );
2310                 $dbw->delete(
2311                         'page_restrictions',
2312                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2313                         __METHOD__
2314                 );
2315
2316                 $dbw->delete(
2317                         'protected_titles',
2318                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2319                         __METHOD__
2320                 );
2321         }
2322
2323         /**
2324          * Accessor/initialisation for mRestrictions
2325          *
2326          * @param $action String action that permission needs to be checked for
2327          * @return Array of Strings the array of groups allowed to edit this article
2328          */
2329         public function getRestrictions( $action ) {
2330                 if ( !$this->mRestrictionsLoaded ) {
2331                         $this->loadRestrictions();
2332                 }
2333                 return isset( $this->mRestrictions[$action] )
2334                                 ? $this->mRestrictions[$action]
2335                                 : array();
2336         }
2337
2338         /**
2339          * Get the expiry time for the restriction against a given action
2340          *
2341          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2342          *      or not protected at all, or false if the action is not recognised.
2343          */
2344         public function getRestrictionExpiry( $action ) {
2345                 if ( !$this->mRestrictionsLoaded ) {
2346                         $this->loadRestrictions();
2347                 }
2348                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2349         }
2350
2351         /**
2352          * Is there a version of this page in the deletion archive?
2353          *
2354          * @param $includeSuppressed Boolean Include suppressed revisions?
2355          * @return Int the number of archived revisions
2356          */
2357         public function isDeleted( $includeSuppressed = false ) {
2358                 if ( $this->getNamespace() < 0 ) {
2359                         $n = 0;
2360                 } else {
2361                         $dbr = wfGetDB( DB_SLAVE );
2362                         $conditions = array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() );
2363
2364                         if( !$includeSuppressed ) {
2365                                 $suppressedTextBits = Revision::DELETED_TEXT | Revision::DELETED_RESTRICTED;
2366                                 $conditions[] = $dbr->bitAnd('ar_deleted', $suppressedTextBits ) .
2367                                 ' != ' . $suppressedTextBits;
2368                         }
2369
2370                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2371                                 $conditions,
2372                                 __METHOD__
2373                         );
2374                         if ( $this->getNamespace() == NS_FILE ) {
2375                                 $fconditions = array( 'fa_name' => $this->getDBkey() );
2376                                 if( !$includeSuppressed ) {
2377                                         $suppressedTextBits = File::DELETED_FILE | File::DELETED_RESTRICTED;
2378                                         $fconditions[] = $dbr->bitAnd('fa_deleted', $suppressedTextBits ) .
2379                                         ' != ' . $suppressedTextBits;
2380                                 }
2381
2382                                 $n += $dbr->selectField( 'filearchive',
2383                                         'COUNT(*)',
2384                                         $fconditions,
2385                                         __METHOD__
2386                                 );
2387                         }
2388                 }
2389                 return (int)$n;
2390         }
2391
2392         /**
2393          * Is there a version of this page in the deletion archive?
2394          *
2395          * @return Boolean
2396          */
2397         public function isDeletedQuick() {
2398                 if ( $this->getNamespace() < 0 ) {
2399                         return false;
2400                 }
2401                 $dbr = wfGetDB( DB_SLAVE );
2402                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2403                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2404                         __METHOD__
2405                 );
2406                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2407                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2408                                 array( 'fa_name' => $this->getDBkey() ),
2409                                 __METHOD__
2410                         );
2411                 }
2412                 return $deleted;
2413         }
2414
2415         /**
2416          * Get the article ID for this Title from the link cache,
2417          * adding it if necessary
2418          *
2419          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2420          *  for update
2421          * @return Int the ID
2422          */
2423         public function getArticleID( $flags = 0 ) {
2424                 if ( $this->getNamespace() < 0 ) {
2425                         return $this->mArticleID = 0;
2426                 }
2427                 $linkCache = LinkCache::singleton();
2428                 if ( $flags & self::GAID_FOR_UPDATE ) {
2429                         $oldUpdate = $linkCache->forUpdate( true );
2430                         $linkCache->clearLink( $this );
2431                         $this->mArticleID = $linkCache->addLinkObj( $this );
2432                         $linkCache->forUpdate( $oldUpdate );
2433                 } else {
2434                         if ( -1 == $this->mArticleID ) {
2435                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2436                         }
2437                 }
2438                 return $this->mArticleID;
2439         }
2440
2441         /**
2442          * Is this an article that is a redirect page?
2443          * Uses link cache, adding it if necessary
2444          *
2445          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2446          * @return Bool
2447          */
2448         public function isRedirect( $flags = 0 ) {
2449                 if ( !is_null( $this->mRedirect ) ) {
2450                         return $this->mRedirect;
2451                 }
2452                 # Calling getArticleID() loads the field from cache as needed
2453                 if ( !$this->getArticleID( $flags ) ) {
2454                         return $this->mRedirect = false;
2455                 }
2456                 $linkCache = LinkCache::singleton();
2457                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2458
2459                 return $this->mRedirect;
2460         }
2461
2462         /**
2463          * What is the length of this page?
2464          * Uses link cache, adding it if necessary
2465          *
2466          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2467          * @return Int
2468          */
2469         public function getLength( $flags = 0 ) {
2470                 if ( $this->mLength != -1 ) {
2471                         return $this->mLength;
2472                 }
2473                 # Calling getArticleID() loads the field from cache as needed
2474                 if ( !$this->getArticleID( $flags ) ) {
2475                         return $this->mLength = 0;
2476                 }
2477                 $linkCache = LinkCache::singleton();
2478                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2479
2480                 return $this->mLength;
2481         }
2482
2483         /**
2484          * What is the page_latest field for this page?
2485          *
2486          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2487          * @return Int or 0 if the page doesn't exist
2488          */
2489         public function getLatestRevID( $flags = 0 ) {
2490                 if ( $this->mLatestID !== false ) {
2491                         return intval( $this->mLatestID );
2492                 }
2493                 # Calling getArticleID() loads the field from cache as needed
2494                 if ( !$this->getArticleID( $flags ) ) {
2495                         return $this->mLatestID = 0;
2496                 }
2497                 $linkCache = LinkCache::singleton();
2498                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2499
2500                 return $this->mLatestID;
2501         }
2502
2503         /**
2504          * This clears some fields in this object, and clears any associated
2505          * keys in the "bad links" section of the link cache.
2506          *
2507          * - This is called from Article::doEdit() and Article::insertOn() to allow
2508          * loading of the new page_id. It's also called from
2509          * Article::doDeleteArticle()
2510          *
2511          * @param $newid Int the new Article ID
2512          */
2513         public function resetArticleID( $newid ) {
2514                 $linkCache = LinkCache::singleton();
2515                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2516
2517                 if ( $newid === false ) {
2518                         $this->mArticleID = -1;
2519                 } else {
2520                         $this->mArticleID = intval( $newid );
2521                 }
2522                 $this->mRestrictionsLoaded = false;
2523                 $this->mRestrictions = array();
2524                 $this->mRedirect = null;
2525                 $this->mLength = -1;
2526                 $this->mLatestID = false;
2527         }
2528
2529         /**
2530          * Updates page_touched for this page; called from LinksUpdate.php
2531          *
2532          * @return Bool true if the update succeded
2533          */
2534         public function invalidateCache() {
2535                 if ( wfReadOnly() ) {
2536                         return;
2537                 }
2538                 $dbw = wfGetDB( DB_MASTER );
2539                 $success = $dbw->update(
2540                         'page',
2541                         array( 'page_touched' => $dbw->timestamp() ),
2542                         $this->pageCond(),
2543                         __METHOD__
2544                 );
2545                 HTMLFileCache::clearFileCache( $this );
2546                 return $success;
2547         }
2548
2549         /**
2550          * Prefix some arbitrary text with the namespace or interwiki prefix
2551          * of this object
2552          *
2553          * @param $name String the text
2554          * @return String the prefixed text
2555          * @private
2556          */
2557         private function prefix( $name ) {
2558                 $p = '';
2559                 if ( $this->mInterwiki != '' ) {
2560                         $p = $this->mInterwiki . ':';
2561                 }
2562
2563                 if ( 0 != $this->mNamespace ) {
2564                         $p .= $this->getNsText() . ':';
2565                 }
2566                 return $p . $name;
2567         }
2568
2569         /**
2570          * Returns a simple regex that will match on characters and sequences invalid in titles.
2571          * Note that this doesn't pick up many things that could be wrong with titles, but that
2572          * replacing this regex with something valid will make many titles valid.
2573          *
2574          * @return String regex string
2575          */
2576         static function getTitleInvalidRegex() {
2577                 static $rxTc = false;
2578                 if ( !$rxTc ) {
2579                         # Matching titles will be held as illegal.
2580                         $rxTc = '/' .
2581                                 # Any character not allowed is forbidden...
2582                                 '[^' . Title::legalChars() . ']' .
2583                                 # URL percent encoding sequences interfere with the ability
2584                                 # to round-trip titles -- you can't link to them consistently.
2585                                 '|%[0-9A-Fa-f]{2}' .
2586                                 # XML/HTML character references produce similar issues.
2587                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2588                                 '|&#[0-9]+;' .
2589                                 '|&#x[0-9A-Fa-f]+;' .
2590                                 '/S';
2591                 }
2592
2593                 return $rxTc;
2594         }
2595
2596         /**
2597          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2598          *
2599          * @param $text String containing title to capitalize
2600          * @param $ns int namespace index, defaults to NS_MAIN
2601          * @return String containing capitalized title
2602          */
2603         public static function capitalize( $text, $ns = NS_MAIN ) {
2604                 global $wgContLang;
2605
2606                 if ( MWNamespace::isCapitalized( $ns ) ) {
2607                         return $wgContLang->ucfirst( $text );
2608                 } else {
2609                         return $text;
2610                 }
2611         }
2612
2613         /**
2614          * Secure and split - main initialisation function for this object
2615          *
2616          * Assumes that mDbkeyform has been set, and is urldecoded
2617          * and uses underscores, but not otherwise munged.  This function
2618          * removes illegal characters, splits off the interwiki and
2619          * namespace prefixes, sets the other forms, and canonicalizes
2620          * everything.
2621          *
2622          * @return Bool true on success
2623          */
2624         private function secureAndSplit() {
2625                 global $wgContLang, $wgLocalInterwiki;
2626
2627                 # Initialisation
2628                 $this->mInterwiki = $this->mFragment = '';
2629                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2630
2631                 $dbkey = $this->mDbkeyform;
2632
2633                 # Strip Unicode bidi override characters.
2634                 # Sometimes they slip into cut-n-pasted page titles, where the
2635                 # override chars get included in list displays.
2636                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2637
2638                 # Clean up whitespace
2639                 # Note: use of the /u option on preg_replace here will cause
2640                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2641                 # conveniently disabling them.
2642                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2643                 $dbkey = trim( $dbkey, '_' );
2644
2645                 if ( $dbkey == '' ) {
2646                         return false;
2647                 }
2648
2649                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2650                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2651                         return false;
2652                 }
2653
2654                 $this->mDbkeyform = $dbkey;
2655
2656                 # Initial colon indicates main namespace rather than specified default
2657                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2658                 if ( ':' == $dbkey[0] ) {
2659                         $this->mNamespace = NS_MAIN;
2660                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2661                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2662                 }
2663
2664                 # Namespace or interwiki prefix
2665                 $firstPass = true;
2666                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2667                 do {
2668                         $m = array();
2669                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2670                                 $p = $m[1];
2671                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2672                                         # Ordinary namespace
2673                                         $dbkey = $m[2];
2674                                         $this->mNamespace = $ns;
2675                                         # For Talk:X pages, check if X has a "namespace" prefix
2676                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2677                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2678                                                         # Disallow Talk:File:x type titles...
2679                                                         return false;
2680                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2681                                                         # Disallow Talk:Interwiki:x type titles...
2682                                                         return false;
2683                                                 }
2684                                         }
2685                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2686                                         if ( !$firstPass ) {
2687                                                 # Can't make a local interwiki link to an interwiki link.
2688                                                 # That's just crazy!
2689                                                 return false;
2690                                         }
2691
2692                                         # Interwiki link
2693                                         $dbkey = $m[2];
2694                                         $this->mInterwiki = $wgContLang->lc( $p );
2695
2696                                         # Redundant interwiki prefix to the local wiki
2697                                         if ( $wgLocalInterwiki !== false
2698                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2699                                         {
2700                                                 if ( $dbkey == '' ) {
2701                                                         # Can't have an empty self-link
2702                                                         return false;
2703                                                 }
2704                                                 $this->mInterwiki = '';
2705                                                 $firstPass = false;
2706                                                 # Do another namespace split...
2707                                                 continue;
2708                                         }
2709
2710                                         # If there's an initial colon after the interwiki, that also
2711                                         # resets the default namespace
2712                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2713                                                 $this->mNamespace = NS_MAIN;
2714                                                 $dbkey = substr( $dbkey, 1 );
2715                                         }
2716                                 }
2717                                 # If there's no recognized interwiki or namespace,
2718                                 # then let the colon expression be part of the title.
2719                         }
2720                         break;
2721                 } while ( true );
2722
2723                 # We already know that some pages won't be in the database!
2724                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2725                         $this->mArticleID = 0;
2726                 }
2727                 $fragment = strstr( $dbkey, '#' );
2728                 if ( false !== $fragment ) {
2729                         $this->setFragment( $fragment );
2730                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2731                         # remove whitespace again: prevents "Foo_bar_#"
2732                         # becoming "Foo_bar_"
2733                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2734                 }
2735
2736                 # Reject illegal characters.
2737                 $rxTc = self::getTitleInvalidRegex();
2738                 if ( preg_match( $rxTc, $dbkey ) ) {
2739                         return false;
2740                 }
2741
2742                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2743                 # reachable due to the way web browsers deal with 'relative' URLs.
2744                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2745                 if ( strpos( $dbkey, '.' ) !== false &&
2746                          ( $dbkey === '.' || $dbkey === '..' ||
2747                            strpos( $dbkey, './' ) === 0  ||
2748                            strpos( $dbkey, '../' ) === 0 ||
2749                            strpos( $dbkey, '/./' ) !== false ||
2750                            strpos( $dbkey, '/../' ) !== false  ||
2751                            substr( $dbkey, -2 ) == '/.' ||
2752                            substr( $dbkey, -3 ) == '/..' ) )
2753                 {
2754                         return false;
2755                 }
2756
2757                 # Magic tilde sequences? Nu-uh!
2758                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2759                         return false;
2760                 }
2761
2762                 # Limit the size of titles to 255 bytes. This is typically the size of the
2763                 # underlying database field. We make an exception for special pages, which
2764                 # don't need to be stored in the database, and may edge over 255 bytes due
2765                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2766                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2767                   strlen( $dbkey ) > 512 )
2768                 {
2769                         return false;
2770                 }
2771
2772                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2773                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2774                 # other site might be case-sensitive.
2775                 $this->mUserCaseDBKey = $dbkey;
2776                 if ( $this->mInterwiki == '' ) {
2777                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2778                 }
2779
2780                 # Can't make a link to a namespace alone... "empty" local links can only be
2781                 # self-links with a fragment identifier.
2782                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2783                         return false;
2784                 }
2785
2786                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2787                 // IP names are not allowed for accounts, and can only be referring to
2788                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2789                 // there are numerous ways to present the same IP. Having sp:contribs scan
2790                 // them all is silly and having some show the edits and others not is
2791                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2792                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2793                         ? IP::sanitizeIP( $dbkey )
2794                         : $dbkey;
2795
2796                 // Any remaining initial :s are illegal.
2797                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2798                         return false;
2799                 }
2800
2801                 # Fill fields
2802                 $this->mDbkeyform = $dbkey;
2803                 $this->mUrlform = wfUrlencode( $dbkey );
2804
2805                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2806
2807                 return true;
2808         }
2809
2810         /**
2811          * Set the fragment for this title. Removes the first character from the
2812          * specified fragment before setting, so it assumes you're passing it with
2813          * an initial "#".
2814          *
2815          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2816          * Still in active use privately.
2817          *
2818          * @param $fragment String text
2819          */
2820         public function setFragment( $fragment ) {
2821                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2822         }
2823
2824         /**
2825          * Get a Title object associated with the talk page of this article
2826          *
2827          * @return Title the object for the talk page
2828          */
2829         public function getTalkPage() {
2830                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2831         }
2832
2833         /**
2834          * Get a title object associated with the subject page of this
2835          * talk page
2836          *
2837          * @return Title the object for the subject page
2838          */
2839         public function getSubjectPage() {
2840                 // Is this the same title?
2841                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2842                 if ( $this->getNamespace() == $subjectNS ) {
2843                         return $this;
2844                 }
2845                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2846         }
2847
2848         /**
2849          * Get an array of Title objects linking to this Title
2850          * Also stores the IDs in the link cache.
2851          *
2852          * WARNING: do not use this function on arbitrary user-supplied titles!
2853          * On heavily-used templates it will max out the memory.
2854          *
2855          * @param $options Array: may be FOR UPDATE
2856          * @param $table String: table name
2857          * @param $prefix String: fields prefix
2858          * @return Array of Title objects linking here
2859          */
2860         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2861                 $linkCache = LinkCache::singleton();
2862
2863                 if ( count( $options ) > 0 ) {
2864                         $db = wfGetDB( DB_MASTER );
2865                 } else {
2866                         $db = wfGetDB( DB_SLAVE );
2867                 }
2868
2869                 $res = $db->select(
2870                         array( 'page', $table ),
2871                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2872                         array(
2873                                 "{$prefix}_from=page_id",
2874                                 "{$prefix}_namespace" => $this->getNamespace(),
2875                                 "{$prefix}_title"     => $this->getDBkey() ),
2876                         __METHOD__,
2877                         $options
2878                 );
2879
2880                 $retVal = array();
2881                 if ( $db->numRows( $res ) ) {
2882                         foreach ( $res as $row ) {
2883                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2884                                 if ( $titleObj ) {
2885                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2886                                         $retVal[] = $titleObj;
2887                                 }
2888                         }
2889                 }
2890                 return $retVal;
2891         }
2892
2893         /**
2894          * Get an array of Title objects using this Title as a template
2895          * Also stores the IDs in the link cache.
2896          *
2897          * WARNING: do not use this function on arbitrary user-supplied titles!
2898          * On heavily-used templates it will max out the memory.
2899          *
2900          * @param $options Array: may be FOR UPDATE
2901          * @return Array of Title the Title objects linking here
2902          */
2903         public function getTemplateLinksTo( $options = array() ) {
2904                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2905         }
2906
2907         /**
2908          * Get an array of Title objects referring to non-existent articles linked from this page
2909          *
2910          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2911          * @return Array of Title the Title objects
2912          */
2913         public function getBrokenLinksFrom() {
2914                 if ( $this->getArticleId() == 0 ) {
2915                         # All links from article ID 0 are false positives
2916                         return array();
2917                 }
2918
2919                 $dbr = wfGetDB( DB_SLAVE );
2920                 $res = $dbr->select(
2921                         array( 'page', 'pagelinks' ),
2922                         array( 'pl_namespace', 'pl_title' ),
2923                         array(
2924                                 'pl_from' => $this->getArticleId(),
2925                                 'page_namespace IS NULL'
2926                         ),
2927                         __METHOD__, array(),
2928                         array(
2929                                 'page' => array(
2930                                         'LEFT JOIN',
2931                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2932                                 )
2933                         )
2934                 );
2935
2936                 $retVal = array();
2937                 foreach ( $res as $row ) {
2938                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2939                 }
2940                 return $retVal;
2941         }
2942
2943
2944         /**
2945          * Get a list of URLs to purge from the Squid cache when this
2946          * page changes
2947          *
2948          * @return Array of String the URLs
2949          */
2950         public function getSquidURLs() {
2951                 global $wgContLang;
2952
2953                 $urls = array(
2954                         $this->getInternalURL(),
2955                         $this->getInternalURL( 'action=history' )
2956                 );
2957
2958                 // purge variant urls as well
2959                 if ( $wgContLang->hasVariants() ) {
2960                         $variants = $wgContLang->getVariants();
2961                         foreach ( $variants as $vCode ) {
2962                                 $urls[] = $this->getInternalURL( '', $vCode );
2963                         }
2964                 }
2965
2966                 return $urls;
2967         }
2968
2969         /**
2970          * Purge all applicable Squid URLs
2971          */
2972         public function purgeSquid() {
2973                 global $wgUseSquid;
2974                 if ( $wgUseSquid ) {
2975                         $urls = $this->getSquidURLs();
2976                         $u = new SquidUpdate( $urls );
2977                         $u->doUpdate();
2978                 }
2979         }
2980
2981         /**
2982          * Move this page without authentication
2983          *
2984          * @param $nt Title the new page Title
2985          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2986          */
2987         public function moveNoAuth( &$nt ) {
2988                 return $this->moveTo( $nt, false );
2989         }
2990
2991         /**
2992          * Check whether a given move operation would be valid.
2993          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2994          *
2995          * @param $nt Title the new title
2996          * @param $auth Bool indicates whether $wgUser's permissions
2997          *  should be checked
2998          * @param $reason String is the log summary of the move, used for spam checking
2999          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3000          */
3001         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3002                 global $wgUser;
3003
3004                 $errors = array();
3005                 if ( !$nt ) {
3006                         // Normally we'd add this to $errors, but we'll get
3007                         // lots of syntax errors if $nt is not an object
3008                         return array( array( 'badtitletext' ) );
3009                 }
3010                 if ( $this->equals( $nt ) ) {
3011                         $errors[] = array( 'selfmove' );
3012                 }
3013                 if ( !$this->isMovable() ) {
3014                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3015                 }
3016                 if ( $nt->getInterwiki() != '' ) {
3017                         $errors[] = array( 'immobile-target-namespace-iw' );
3018                 }
3019                 if ( !$nt->isMovable() ) {
3020                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3021                 }
3022
3023                 $oldid = $this->getArticleID();
3024                 $newid = $nt->getArticleID();
3025
3026                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3027                         $errors[] = array( 'articleexists' );
3028                 }
3029                 if ( ( $this->getDBkey() == '' ) ||
3030                          ( !$oldid ) ||
3031                          ( $nt->getDBkey() == '' ) ) {
3032                         $errors[] = array( 'badarticleerror' );
3033                 }
3034
3035                 // Image-specific checks
3036                 if ( $this->getNamespace() == NS_FILE ) {
3037                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3038                 }
3039
3040                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3041                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3042                 }
3043
3044                 if ( $auth ) {
3045                         $errors = wfMergeErrorArrays( $errors,
3046                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3047                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3048                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3049                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3050                 }
3051
3052                 $match = EditPage::matchSummarySpamRegex( $reason );
3053                 if ( $match !== false ) {
3054                         // This is kind of lame, won't display nice
3055                         $errors[] = array( 'spamprotectiontext' );
3056                 }
3057
3058                 $err = null;
3059                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3060                         $errors[] = array( 'hookaborted', $err );
3061                 }
3062
3063                 # The move is allowed only if (1) the target doesn't exist, or
3064                 # (2) the target is a redirect to the source, and has no history
3065                 # (so we can undo bad moves right after they're done).
3066
3067                 if ( 0 != $newid ) { # Target exists; check for validity
3068                         if ( !$this->isValidMoveTarget( $nt ) ) {
3069                                 $errors[] = array( 'articleexists' );
3070                         }
3071                 } else {
3072                         $tp = $nt->getTitleProtection();
3073                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3074                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3075                                 $errors[] = array( 'cantmove-titleprotected' );
3076                         }
3077                 }
3078                 if ( empty( $errors ) ) {
3079                         return true;
3080                 }
3081                 return $errors;
3082         }
3083
3084         /**
3085          * Check if the requested move target is a valid file move target
3086          * @param Title $nt Target title
3087          * @return array List of errors
3088          */
3089         protected function validateFileMoveOperation( $nt ) {
3090                 global $wgUser;
3091
3092                 $errors = array();
3093
3094                 if ( $nt->getNamespace() != NS_FILE ) {
3095                         $errors[] = array( 'imagenocrossnamespace' );
3096                 }
3097
3098                 $file = wfLocalFile( $this );
3099                 if ( $file->exists() ) {
3100                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3101                                 $errors[] = array( 'imageinvalidfilename' );
3102                         }
3103                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3104                                 $errors[] = array( 'imagetypemismatch' );
3105                         }
3106                 }
3107
3108                 $destFile = wfLocalFile( $nt );
3109                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3110                         $errors[] = array( 'file-exists-sharedrepo' );
3111                 }
3112
3113                 return $errors;
3114         }
3115
3116         /**
3117          * Move a title to a new location
3118          *
3119          * @param $nt Title the new title
3120          * @param $auth Bool indicates whether $wgUser's permissions
3121          *  should be checked
3122          * @param $reason String the reason for the move
3123          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3124          *  Ignored if the user doesn't have the suppressredirect right.
3125          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3126          */
3127         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3128                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3129                 if ( is_array( $err ) ) {
3130                         return $err;
3131                 }
3132
3133                 // If it is a file, move it first. It is done before all other moving stuff is
3134                 // done because it's hard to revert
3135                 $dbw = wfGetDB( DB_MASTER );
3136                 if ( $this->getNamespace() == NS_FILE ) {
3137                         $file = wfLocalFile( $this );
3138                         if ( $file->exists() ) {
3139                                 $status = $file->move( $nt );
3140                                 if ( !$status->isOk() ) {
3141                                         return $status->getErrorsArray();
3142                                 }
3143                         }
3144                 }
3145
3146                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3147                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3148                 $protected = $this->isProtected();
3149                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3150
3151                 // Do the actual move
3152                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3153                 if ( is_array( $err ) ) {
3154                         # @todo FIXME: What about the File we have already moved?
3155                         $dbw->rollback();
3156                         return $err;
3157                 }
3158
3159                 $redirid = $this->getArticleID();
3160
3161                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3162                 // cl_timestamp, which may disturb time-based lists on some sites.
3163                 $prefixes = $dbw->select(
3164                         'categorylinks',
3165                         array( 'cl_sortkey_prefix', 'cl_to' ),
3166                         array( 'cl_from' => $pageid ),
3167                         __METHOD__
3168                 );
3169                 foreach ( $prefixes as $prefixRow ) {
3170                         $prefix = $prefixRow->cl_sortkey_prefix;
3171                         $catTo = $prefixRow->cl_to;
3172                         $dbw->update( 'categorylinks',
3173                                 array(
3174                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3175                                                 $nt->getCategorySortkey( $prefix ) ),
3176                                         'cl_timestamp=cl_timestamp' ),
3177                                 array(
3178                                         'cl_from' => $pageid,
3179                                         'cl_to' => $catTo ),
3180                                 __METHOD__
3181                         );
3182                 }
3183
3184                 if ( $protected ) {
3185                         # Protect the redirect title as the title used to be...
3186                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3187                                 array(
3188                                         'pr_page'    => $redirid,
3189                                         'pr_type'    => 'pr_type',
3190                                         'pr_level'   => 'pr_level',
3191                                         'pr_cascade' => 'pr_cascade',
3192                                         'pr_user'    => 'pr_user',
3193                                         'pr_expiry'  => 'pr_expiry'
3194                                 ),
3195                                 array( 'pr_page' => $pageid ),
3196                                 __METHOD__,
3197                                 array( 'IGNORE' )
3198                         );
3199                         # Update the protection log
3200                         $log = new LogPage( 'protect' );
3201                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3202                         if ( $reason ) {
3203                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3204                         }
3205                         // @todo FIXME: $params?
3206                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3207                 }
3208
3209                 # Update watchlists
3210                 $oldnamespace = $this->getNamespace() & ~1;
3211                 $newnamespace = $nt->getNamespace() & ~1;
3212                 $oldtitle = $this->getDBkey();
3213                 $newtitle = $nt->getDBkey();
3214
3215                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3216                         WatchedItem::duplicateEntries( $this, $nt );
3217                 }
3218
3219                 # Update search engine
3220                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3221                 $u->doUpdate();
3222                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3223                 $u->doUpdate();
3224
3225                 $dbw->commit();
3226
3227                 # Update site_stats
3228                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3229                         # No longer a content page
3230                         # Not viewed, edited, removing
3231                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3232                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3233                         # Now a content page
3234                         # Not viewed, edited, adding
3235                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3236                 } elseif ( $pageCountChange ) {
3237                         # Redirect added
3238                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3239                 } else {
3240                         # Nothing special
3241                         $u = false;
3242                 }
3243                 if ( $u ) {
3244                         $u->doUpdate();
3245                 }
3246
3247                 # Update message cache for interface messages
3248                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3249                         # @bug 17860: old article can be deleted, if this the case,
3250                         # delete it from message cache
3251                         if ( $this->getArticleID() === 0 ) {
3252                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3253                         } else {
3254                                 $oldarticle = new Article( $this );
3255                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3256                         }
3257                 }
3258                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3259                         $newarticle = new Article( $nt );
3260                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3261                 }
3262
3263                 global $wgUser;
3264                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3265                 return true;
3266         }
3267
3268         /**
3269          * Move page to a title which is either a redirect to the
3270          * source page or nonexistent
3271          *
3272          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3273          * @param $reason String The reason for the move
3274          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3275          *   if the user doesn't have the suppressredirect right
3276          */
3277         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3278                 global $wgUser, $wgContLang;
3279
3280                 $moveOverRedirect = $nt->exists();
3281
3282                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3283                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3284
3285                 if ( $reason ) {
3286                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3287                 }
3288                 # Truncate for whole multibyte characters.
3289                 $comment = $wgContLang->truncate( $comment, 255 );
3290
3291                 $oldid = $this->getArticleID();
3292                 $latest = $this->getLatestRevID();
3293
3294                 $dbw = wfGetDB( DB_MASTER );
3295
3296                 if ( $moveOverRedirect ) {
3297                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3298
3299                         $newid = $nt->getArticleID();
3300                         $newns = $nt->getNamespace();
3301                         $newdbk = $nt->getDBkey();
3302
3303                         # Delete the old redirect. We don't save it to history since
3304                         # by definition if we've got here it's rather uninteresting.
3305                         # We have to remove it so that the next step doesn't trigger
3306                         # a conflict on the unique namespace+title index...
3307                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3308                         if ( !$dbw->cascadingDeletes() ) {
3309                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3310                                 global $wgUseTrackbacks;
3311                                 if ( $wgUseTrackbacks ) {
3312                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3313                                 }
3314                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3315                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3316                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3317                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3318                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3319                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3320                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3321                         }
3322                         // If the target page was recently created, it may have an entry in recentchanges still
3323                         $dbw->delete( 'recentchanges',
3324                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3325                                 __METHOD__
3326                         );
3327                 }
3328
3329                 # Save a null revision in the page's history notifying of the move
3330                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3331                 if ( !is_object( $nullRevision ) ) {
3332                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3333                 }
3334                 $nullRevId = $nullRevision->insertOn( $dbw );
3335
3336                 $now = wfTimestampNow();
3337                 # Change the name of the target page:
3338                 $dbw->update( 'page',
3339                         /* SET */ array(
3340                                 'page_touched'   => $dbw->timestamp( $now ),
3341                                 'page_namespace' => $nt->getNamespace(),
3342                                 'page_title'     => $nt->getDBkey(),
3343                                 'page_latest'    => $nullRevId,
3344                         ),
3345                         /* WHERE */ array( 'page_id' => $oldid ),
3346                         __METHOD__
3347                 );
3348                 $nt->resetArticleID( $oldid );
3349
3350                 $article = new Article( $nt );
3351                 wfRunHooks( 'NewRevisionFromEditComplete',
3352                         array( $article, $nullRevision, $latest, $wgUser ) );
3353                 $article->setCachedLastEditTime( $now );
3354
3355                 # Recreate the redirect, this time in the other direction.
3356                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3357                         $mwRedir = MagicWord::get( 'redirect' );
3358                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3359                         $redirectArticle = new Article( $this );
3360                         $newid = $redirectArticle->insertOn( $dbw );
3361                         if ( $newid ) { // sanity
3362                                 $redirectRevision = new Revision( array(
3363                                         'page'    => $newid,
3364                                         'comment' => $comment,
3365                                         'text'    => $redirectText ) );
3366                                 $redirectRevision->insertOn( $dbw );
3367                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3368
3369                                 wfRunHooks( 'NewRevisionFromEditComplete',
3370                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3371
3372                                 # Now, we record the link from the redirect to the new title.
3373                                 # It should have no other outgoing links...
3374                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3375                                 $dbw->insert( 'pagelinks',
3376                                         array(
3377                                                 'pl_from'      => $newid,
3378                                                 'pl_namespace' => $nt->getNamespace(),
3379                                                 'pl_title'     => $nt->getDBkey() ),
3380                                         __METHOD__ );
3381                         }
3382                         $redirectSuppressed = false;
3383                 } else {
3384                         $this->resetArticleID( 0 );
3385                         $redirectSuppressed = true;
3386                 }
3387
3388                 # Log the move
3389                 $log = new LogPage( 'move' );
3390                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3391                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3392
3393                 # Purge caches for old and new titles
3394                 if ( $moveOverRedirect ) {
3395                         # A simple purge is enough when moving over a redirect
3396                         $nt->purgeSquid();
3397                 } else {
3398                         # Purge caches as per article creation, including any pages that link to this title
3399                         Article::onArticleCreate( $nt );
3400                 }
3401                 $this->purgeSquid();
3402         }
3403
3404         /**
3405          * Move this page's subpages to be subpages of $nt
3406          *
3407          * @param $nt Title Move target
3408          * @param $auth bool Whether $wgUser's permissions should be checked
3409          * @param $reason string The reason for the move
3410          * @param $createRedirect bool Whether to create redirects from the old subpages to
3411          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3412          * @return mixed array with old page titles as keys, and strings (new page titles) or
3413          *     arrays (errors) as values, or an error array with numeric indices if no pages
3414          *     were moved
3415          */
3416         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3417                 global $wgMaximumMovedPages;
3418                 // Check permissions
3419                 if ( !$this->userCan( 'move-subpages' ) ) {
3420                         return array( 'cant-move-subpages' );
3421                 }
3422                 // Do the source and target namespaces support subpages?
3423                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3424                         return array( 'namespace-nosubpages',
3425                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3426                 }
3427                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3428                         return array( 'namespace-nosubpages',
3429                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3430                 }
3431
3432                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3433                 $retval = array();
3434                 $count = 0;
3435                 foreach ( $subpages as $oldSubpage ) {
3436                         $count++;
3437                         if ( $count > $wgMaximumMovedPages ) {
3438                                 $retval[$oldSubpage->getPrefixedTitle()] =
3439                                                 array( 'movepage-max-pages',
3440                                                         $wgMaximumMovedPages );
3441                                 break;
3442                         }
3443
3444                         // We don't know whether this function was called before
3445                         // or after moving the root page, so check both
3446                         // $this and $nt
3447                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3448                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3449                         {
3450                                 // When moving a page to a subpage of itself,
3451                                 // don't move it twice
3452                                 continue;
3453                         }
3454                         $newPageName = preg_replace(
3455                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3456                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3457                                         $oldSubpage->getDBkey() );
3458                         if ( $oldSubpage->isTalkPage() ) {
3459                                 $newNs = $nt->getTalkPage()->getNamespace();
3460                         } else {
3461                                 $newNs = $nt->getSubjectPage()->getNamespace();
3462                         }
3463                         # Bug 14385: we need makeTitleSafe because the new page names may
3464                         # be longer than 255 characters.
3465                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3466
3467                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3468                         if ( $success === true ) {
3469                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3470                         } else {
3471                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3472                         }
3473                 }
3474                 return $retval;
3475         }
3476
3477         /**
3478          * Checks if this page is just a one-rev redirect.
3479          * Adds lock, so don't use just for light purposes.
3480          *
3481          * @return Bool
3482          */
3483         public function isSingleRevRedirect() {
3484                 $dbw = wfGetDB( DB_MASTER );
3485                 # Is it a redirect?
3486                 $row = $dbw->selectRow( 'page',
3487                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3488                         $this->pageCond(),
3489                         __METHOD__,
3490                         array( 'FOR UPDATE' )
3491                 );
3492                 # Cache some fields we may want
3493                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3494                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3495                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3496                 if ( !$this->mRedirect ) {
3497                         return false;
3498                 }
3499                 # Does the article have a history?
3500                 $row = $dbw->selectField( array( 'page', 'revision' ),
3501                         'rev_id',
3502                         array( 'page_namespace' => $this->getNamespace(),
3503                                 'page_title' => $this->getDBkey(),
3504                                 'page_id=rev_page',
3505                                 'page_latest != rev_id'
3506                         ),
3507                         __METHOD__,
3508                         array( 'FOR UPDATE' )
3509                 );
3510                 # Return true if there was no history
3511                 return ( $row === false );
3512         }
3513
3514         /**
3515          * Checks if $this can be moved to a given Title
3516          * - Selects for update, so don't call it unless you mean business
3517          *
3518          * @param $nt Title the new title to check
3519          * @return Bool
3520          */
3521         public function isValidMoveTarget( $nt ) {
3522                 # Is it an existing file?
3523                 if ( $nt->getNamespace() == NS_FILE ) {
3524                         $file = wfLocalFile( $nt );
3525                         if ( $file->exists() ) {
3526                                 wfDebug( __METHOD__ . ": file exists\n" );
3527                                 return false;
3528                         }
3529                 }
3530                 # Is it a redirect with no history?
3531                 if ( !$nt->isSingleRevRedirect() ) {
3532                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3533                         return false;
3534                 }
3535                 # Get the article text
3536                 $rev = Revision::newFromTitle( $nt );
3537                 $text = $rev->getText();
3538                 # Does the redirect point to the source?
3539                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3540                 $m = array();
3541                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3542                         $redirTitle = Title::newFromText( $m[1] );
3543                         if ( !is_object( $redirTitle ) ||
3544                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3545                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3546                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3547                                 return false;
3548                         }
3549                 } else {
3550                         # Fail safe
3551                         wfDebug( __METHOD__ . ": failsafe\n" );
3552                         return false;
3553                 }
3554                 return true;
3555         }
3556
3557         /**
3558          * Can this title be added to a user's watchlist?
3559          *
3560          * @return Bool TRUE or FALSE
3561          */
3562         public function isWatchable() {
3563                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3564         }
3565
3566         /**
3567          * Get categories to which this Title belongs and return an array of
3568          * categories' names.
3569          *
3570          * @return Array of parents in the form:
3571          *        $parent => $currentarticle
3572          */
3573         public function getParentCategories() {
3574                 global $wgContLang;
3575
3576                 $data = array();
3577
3578                 $titleKey = $this->getArticleId();
3579
3580                 if ( $titleKey === 0 ) {
3581                         return $data;
3582                 }
3583
3584                 $dbr = wfGetDB( DB_SLAVE );
3585
3586                 $res = $dbr->select( 'categorylinks', '*',
3587                         array(
3588                                 'cl_from' => $titleKey,
3589                         ),
3590                         __METHOD__,
3591                         array()
3592                 );
3593
3594                 if ( $dbr->numRows( $res ) > 0 ) {
3595                         foreach ( $res as $row ) {
3596                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3597                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3598                         }
3599                 }
3600                 return $data;
3601         }
3602
3603         /**
3604          * Get a tree of parent categories
3605          *
3606          * @param $children Array with the children in the keys, to check for circular refs
3607          * @return Array Tree of parent categories
3608          */
3609         public function getParentCategoryTree( $children = array() ) {
3610                 $stack = array();
3611                 $parents = $this->getParentCategories();
3612
3613                 if ( $parents ) {
3614                         foreach ( $parents as $parent => $current ) {
3615                                 if ( array_key_exists( $parent, $children ) ) {
3616                                         # Circular reference
3617                                         $stack[$parent] = array();
3618                                 } else {
3619                                         $nt = Title::newFromText( $parent );
3620                                         if ( $nt ) {
3621                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3622                                         }
3623                                 }
3624                         }
3625                 }
3626
3627                 return $stack;
3628         }
3629
3630         /**
3631          * Get an associative array for selecting this title from
3632          * the "page" table
3633          *
3634          * @return Array suitable for the $where parameter of DB::select()
3635          */
3636         public function pageCond() {
3637                 if ( $this->mArticleID > 0 ) {
3638                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3639                         return array( 'page_id' => $this->mArticleID );
3640                 } else {
3641                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3642                 }
3643         }
3644
3645         /**
3646          * Get the revision ID of the previous revision
3647          *
3648          * @param $revId Int Revision ID. Get the revision that was before this one.
3649          * @param $flags Int Title::GAID_FOR_UPDATE
3650          * @return Int|Bool Old revision ID, or FALSE if none exists
3651          */
3652         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3653                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3654                 return $db->selectField( 'revision', 'rev_id',
3655                         array(
3656                                 'rev_page' => $this->getArticleId( $flags ),
3657                                 'rev_id < ' . intval( $revId )
3658                         ),
3659                         __METHOD__,
3660                         array( 'ORDER BY' => 'rev_id DESC' )
3661                 );
3662         }
3663
3664         /**
3665          * Get the revision ID of the next revision
3666          *
3667          * @param $revId Int Revision ID. Get the revision that was after this one.
3668          * @param $flags Int Title::GAID_FOR_UPDATE
3669          * @return Int|Bool Next revision ID, or FALSE if none exists
3670          */
3671         public function getNextRevisionID( $revId, $flags = 0 ) {
3672                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3673                 return $db->selectField( 'revision', 'rev_id',
3674                         array(
3675                                 'rev_page' => $this->getArticleId( $flags ),
3676                                 'rev_id > ' . intval( $revId )
3677                         ),
3678                         __METHOD__,
3679                         array( 'ORDER BY' => 'rev_id' )
3680                 );
3681         }
3682
3683         /**
3684          * Get the first revision of the page
3685          *
3686          * @param $flags Int Title::GAID_FOR_UPDATE
3687          * @return Revision|Null if page doesn't exist
3688          */
3689         public function getFirstRevision( $flags = 0 ) {
3690                 $pageId = $this->getArticleId( $flags );
3691                 if ( $pageId ) {
3692                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3693                         $row = $db->selectRow( 'revision', '*',
3694                                 array( 'rev_page' => $pageId ),
3695                                 __METHOD__,
3696                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3697                         );
3698                         if ( $row ) {
3699                                 return new Revision( $row );
3700                         }
3701                 }
3702                 return null;
3703         }
3704
3705         /**
3706          * Get the oldest revision timestamp of this page
3707          *
3708          * @param $flags Int Title::GAID_FOR_UPDATE
3709          * @return String: MW timestamp
3710          */
3711         public function getEarliestRevTime( $flags = 0 ) {
3712                 $rev = $this->getFirstRevision( $flags );
3713                 return $rev ? $rev->getTimestamp() : null;
3714         }
3715
3716         /**
3717          * Check if this is a new page
3718          *
3719          * @return bool
3720          */
3721         public function isNewPage() {
3722                 $dbr = wfGetDB( DB_SLAVE );
3723                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3724         }
3725
3726         /**
3727          * Get the number of revisions between the given revision.
3728          * Used for diffs and other things that really need it.
3729          *
3730          * @param $old int|Revision Old revision or rev ID (first before range)
3731          * @param $new int|Revision New revision or rev ID (first after range)
3732          * @return Int Number of revisions between these revisions.
3733          */
3734         public function countRevisionsBetween( $old, $new ) {
3735                 if ( !( $old instanceof Revision ) ) {
3736                         $old = Revision::newFromTitle( $this, (int)$old );
3737                 }
3738                 if ( !( $new instanceof Revision ) ) {
3739                         $new = Revision::newFromTitle( $this, (int)$new );
3740                 }
3741                 if ( !$old || !$new ) {
3742                         return 0; // nothing to compare
3743                 }
3744                 $dbr = wfGetDB( DB_SLAVE );
3745                 return (int)$dbr->selectField( 'revision', 'count(*)',
3746                         array(
3747                                 'rev_page' => $this->getArticleId(),
3748                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3749                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3750                         ),
3751                         __METHOD__
3752                 );
3753         }
3754
3755         /**
3756          * Get the number of authors between the given revision IDs.
3757          * Used for diffs and other things that really need it.
3758          *
3759          * @param $old int|Revision Old revision or rev ID (first before range)
3760          * @param $new int|Revision New revision or rev ID (first after range)
3761          * @param $limit Int Maximum number of authors
3762          * @return Int Number of revision authors between these revisions.
3763          */
3764         public function countAuthorsBetween( $old, $new, $limit ) {
3765                 if ( !( $old instanceof Revision ) ) {
3766                         $old = Revision::newFromTitle( $this, (int)$old );
3767                 }
3768                 if ( !( $new instanceof Revision ) ) {
3769                         $new = Revision::newFromTitle( $this, (int)$new );
3770                 }
3771                 if ( !$old || !$new ) {
3772                         return 0; // nothing to compare
3773                 }
3774                 $dbr = wfGetDB( DB_SLAVE );
3775                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3776                         array(
3777                                 'rev_page' => $this->getArticleID(),
3778                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3779                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3780                         ), __METHOD__,
3781                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3782                 );
3783                 return (int)$dbr->numRows( $res );
3784         }
3785
3786         /**
3787          * Compare with another title.
3788          *
3789          * @param $title Title
3790          * @return Bool
3791          */
3792         public function equals( Title $title ) {
3793                 // Note: === is necessary for proper matching of number-like titles.
3794                 return $this->getInterwiki() === $title->getInterwiki()
3795                         && $this->getNamespace() == $title->getNamespace()
3796                         && $this->getDBkey() === $title->getDBkey();
3797         }
3798
3799         /**
3800          * Callback for usort() to do title sorts by (namespace, title)
3801          *
3802          * @param $a Title
3803          * @param $b Title
3804          *
3805          * @return Integer: result of string comparison, or namespace comparison
3806          */
3807         public static function compare( $a, $b ) {
3808                 if ( $a->getNamespace() == $b->getNamespace() ) {
3809                         return strcmp( $a->getText(), $b->getText() );
3810                 } else {
3811                         return $a->getNamespace() - $b->getNamespace();
3812                 }
3813         }
3814
3815         /**
3816          * Return a string representation of this title
3817          *
3818          * @return String representation of this title
3819          */
3820         public function __toString() {
3821                 return $this->getPrefixedText();
3822         }
3823
3824         /**
3825          * Check if page exists.  For historical reasons, this function simply
3826          * checks for the existence of the title in the page table, and will
3827          * thus return false for interwiki links, special pages and the like.
3828          * If you want to know if a title can be meaningfully viewed, you should
3829          * probably call the isKnown() method instead.
3830          *
3831          * @return Bool
3832          */
3833         public function exists() {
3834                 return $this->getArticleId() != 0;
3835         }
3836
3837         /**
3838          * Should links to this title be shown as potentially viewable (i.e. as
3839          * "bluelinks"), even if there's no record by this title in the page
3840          * table?
3841          *
3842          * This function is semi-deprecated for public use, as well as somewhat
3843          * misleadingly named.  You probably just want to call isKnown(), which
3844          * calls this function internally.
3845          *
3846          * (ISSUE: Most of these checks are cheap, but the file existence check
3847          * can potentially be quite expensive.  Including it here fixes a lot of
3848          * existing code, but we might want to add an optional parameter to skip
3849          * it and any other expensive checks.)
3850          *
3851          * @return Bool
3852          */
3853         public function isAlwaysKnown() {
3854                 if ( $this->mInterwiki != '' ) {
3855                         return true;  // any interwiki link might be viewable, for all we know
3856                 }
3857                 switch( $this->mNamespace ) {
3858                         case NS_MEDIA:
3859                         case NS_FILE:
3860                                 // file exists, possibly in a foreign repo
3861                                 return (bool)wfFindFile( $this );
3862                         case NS_SPECIAL:
3863                                 // valid special page
3864                                 return SpecialPageFactory::exists( $this->getDBkey() );
3865                         case NS_MAIN:
3866                                 // selflink, possibly with fragment
3867                                 return $this->mDbkeyform == '';
3868                         case NS_MEDIAWIKI:
3869                                 // known system message
3870                                 return $this->getDefaultMessageText() !== false;
3871                         default:
3872                                 return false;
3873                 }
3874         }
3875
3876         /**
3877          * Does this title refer to a page that can (or might) be meaningfully
3878          * viewed?  In particular, this function may be used to determine if
3879          * links to the title should be rendered as "bluelinks" (as opposed to
3880          * "redlinks" to non-existent pages).
3881          *
3882          * @return Bool
3883          */
3884         public function isKnown() {
3885                 return $this->isAlwaysKnown() || $this->exists();
3886         }
3887
3888         /**
3889          * Does this page have source text?
3890          *
3891          * @return Boolean
3892          */
3893         public function hasSourceText() {
3894                 if ( $this->exists() ) {
3895                         return true;
3896                 }
3897
3898                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3899                         // If the page doesn't exist but is a known system message, default
3900                         // message content will be displayed, same for language subpages
3901                         return $this->getDefaultMessageText() !== false;
3902                 }
3903
3904                 return false;
3905         }
3906
3907         /**
3908          * Get the default message text or false if the message doesn't exist
3909          *
3910          * @return String or false
3911          */
3912         public function getDefaultMessageText() {
3913                 global $wgContLang;
3914
3915                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3916                         return false;
3917                 }
3918
3919                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3920                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3921
3922                 if ( $message->exists() ) {
3923                         return $message->plain();
3924                 } else {
3925                         return false;
3926                 }
3927         }
3928
3929         /**
3930          * Is this in a namespace that allows actual pages?
3931          *
3932          * @return Bool
3933          * @internal note -- uses hardcoded namespace index instead of constants
3934          */
3935         public function canExist() {
3936                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3937         }
3938
3939         /**
3940          * Update page_touched timestamps and send squid purge messages for
3941          * pages linking to this title. May be sent to the job queue depending
3942          * on the number of links. Typically called on create and delete.
3943          */
3944         public function touchLinks() {
3945                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3946                 $u->doUpdate();
3947
3948                 if ( $this->getNamespace() == NS_CATEGORY ) {
3949                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3950                         $u->doUpdate();
3951                 }
3952         }
3953
3954         /**
3955          * Get the last touched timestamp
3956          *
3957          * @param $db DatabaseBase: optional db
3958          * @return String last-touched timestamp
3959          */
3960         public function getTouched( $db = null ) {
3961                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3962                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3963                 return $touched;
3964         }
3965
3966         /**
3967          * Get the timestamp when this page was updated since the user last saw it.
3968          *
3969          * @param $user User
3970          * @return String|Null
3971          */
3972         public function getNotificationTimestamp( $user = null ) {
3973                 global $wgUser, $wgShowUpdatedMarker;
3974                 // Assume current user if none given
3975                 if ( !$user ) {
3976                         $user = $wgUser;
3977                 }
3978                 // Check cache first
3979                 $uid = $user->getId();
3980                 // avoid isset here, as it'll return false for null entries
3981                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
3982                         return $this->mNotificationTimestamp[$uid];
3983                 }
3984                 if ( !$uid || !$wgShowUpdatedMarker ) {
3985                         return $this->mNotificationTimestamp[$uid] = false;
3986                 }
3987                 // Don't cache too much!
3988                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3989                         $this->mNotificationTimestamp = array();
3990                 }
3991                 $dbr = wfGetDB( DB_SLAVE );
3992                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3993                         'wl_notificationtimestamp',
3994                         array( 'wl_namespace' => $this->getNamespace(),
3995                                 'wl_title' => $this->getDBkey(),
3996                                 'wl_user' => $user->getId()
3997                         ),
3998                         __METHOD__
3999                 );
4000                 return $this->mNotificationTimestamp[$uid];
4001         }
4002
4003         /**
4004          * Get the trackback URL for this page
4005          *
4006          * @return String Trackback URL
4007          */
4008         public function trackbackURL() {
4009                 global $wgScriptPath, $wgServer, $wgScriptExtension;
4010
4011                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
4012                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
4013         }
4014
4015         /**
4016          * Get the trackback RDF for this page
4017          *
4018          * @return String Trackback RDF
4019          */
4020         public function trackbackRDF() {
4021                 $url = htmlspecialchars( $this->getFullURL() );
4022                 $title = htmlspecialchars( $this->getText() );
4023                 $tburl = $this->trackbackURL();
4024
4025                 // Autodiscovery RDF is placed in comments so HTML validator
4026                 // won't barf. This is a rather icky workaround, but seems
4027                 // frequently used by this kind of RDF thingy.
4028                 //
4029                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4030                 return "<!--
4031 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4032                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4033                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4034 <rdf:Description
4035    rdf:about=\"$url\"
4036    dc:identifier=\"$url\"
4037    dc:title=\"$title\"
4038    trackback:ping=\"$tburl\" />
4039 </rdf:RDF>
4040 -->";
4041         }
4042
4043         /**
4044          * Generate strings used for xml 'id' names in monobook tabs
4045          *
4046          * @param $prepend string defaults to 'nstab-'
4047          * @return String XML 'id' name
4048          */
4049         public function getNamespaceKey( $prepend = 'nstab-' ) {
4050                 global $wgContLang;
4051                 // Gets the subject namespace if this title
4052                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4053                 // Checks if cononical namespace name exists for namespace
4054                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4055                         // Uses canonical namespace name
4056                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4057                 } else {
4058                         // Uses text of namespace
4059                         $namespaceKey = $this->getSubjectNsText();
4060                 }
4061                 // Makes namespace key lowercase
4062                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4063                 // Uses main
4064                 if ( $namespaceKey == '' ) {
4065                         $namespaceKey = 'main';
4066                 }
4067                 // Changes file to image for backwards compatibility
4068                 if ( $namespaceKey == 'file' ) {
4069                         $namespaceKey = 'image';
4070                 }
4071                 return $prepend . $namespaceKey;
4072         }
4073
4074         /**
4075          * Returns true if this is a special page.
4076          *
4077          * @return boolean
4078          */
4079         public function isSpecialPage() {
4080                 return $this->getNamespace() == NS_SPECIAL;
4081         }
4082
4083         /**
4084          * Returns true if this title resolves to the named special page
4085          *
4086          * @param $name String The special page name
4087          * @return boolean
4088          */
4089         public function isSpecial( $name ) {
4090                 if ( $this->getNamespace() == NS_SPECIAL ) {
4091                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4092                         if ( $name == $thisName ) {
4093                                 return true;
4094                         }
4095                 }
4096                 return false;
4097         }
4098
4099         /**
4100          * If the Title refers to a special page alias which is not the local default, resolve
4101          * the alias, and localise the name as necessary.  Otherwise, return $this
4102          *
4103          * @return Title
4104          */
4105         public function fixSpecialName() {
4106                 if ( $this->getNamespace() == NS_SPECIAL ) {
4107                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4108                         if ( $canonicalName ) {
4109                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4110                                 if ( $localName != $this->mDbkeyform ) {
4111                                         return Title::makeTitle( NS_SPECIAL, $localName );
4112                                 }
4113                         }
4114                 }
4115                 return $this;
4116         }
4117
4118         /**
4119          * Is this Title in a namespace which contains content?
4120          * In other words, is this a content page, for the purposes of calculating
4121          * statistics, etc?
4122          *
4123          * @return Boolean
4124          */
4125         public function isContentPage() {
4126                 return MWNamespace::isContent( $this->getNamespace() );
4127         }
4128
4129         /**
4130          * Get all extant redirects to this Title
4131          *
4132          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4133          * @return Array of Title redirects to this title
4134          */
4135         public function getRedirectsHere( $ns = null ) {
4136                 $redirs = array();
4137
4138                 $dbr = wfGetDB( DB_SLAVE );
4139                 $where = array(
4140                         'rd_namespace' => $this->getNamespace(),
4141                         'rd_title' => $this->getDBkey(),
4142                         'rd_from = page_id'
4143                 );
4144                 if ( !is_null( $ns ) ) {
4145                         $where['page_namespace'] = $ns;
4146                 }
4147
4148                 $res = $dbr->select(
4149                         array( 'redirect', 'page' ),
4150                         array( 'page_namespace', 'page_title' ),
4151                         $where,
4152                         __METHOD__
4153                 );
4154
4155                 foreach ( $res as $row ) {
4156                         $redirs[] = self::newFromRow( $row );
4157                 }
4158                 return $redirs;
4159         }
4160
4161         /**
4162          * Check if this Title is a valid redirect target
4163          *
4164          * @return Bool
4165          */
4166         public function isValidRedirectTarget() {
4167                 global $wgInvalidRedirectTargets;
4168
4169                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4170                 if ( $this->isSpecial( 'Userlogout' ) ) {
4171                         return false;
4172                 }
4173
4174                 foreach ( $wgInvalidRedirectTargets as $target ) {
4175                         if ( $this->isSpecial( $target ) ) {
4176                                 return false;
4177                         }
4178                 }
4179
4180                 return true;
4181         }
4182
4183         /**
4184          * Get a backlink cache object
4185          *
4186          * @return object BacklinkCache
4187          */
4188         function getBacklinkCache() {
4189                 if ( is_null( $this->mBacklinkCache ) ) {
4190                         $this->mBacklinkCache = new BacklinkCache( $this );
4191                 }
4192                 return $this->mBacklinkCache;
4193         }
4194
4195         /**
4196          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4197          *
4198          * @return Boolean
4199          */
4200         public function canUseNoindex() {
4201                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4202
4203                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4204                         ? $wgContentNamespaces
4205                         : $wgExemptFromUserRobotsControl;
4206
4207                 return !in_array( $this->mNamespace, $bannedNamespaces );
4208
4209         }
4210
4211         /**
4212          * Returns restriction types for the current Title
4213          *
4214          * @return array applicable restriction types
4215          */
4216         public function getRestrictionTypes() {
4217                 if ( $this->getNamespace() == NS_SPECIAL ) {
4218                         return array();
4219                 }
4220
4221                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4222
4223                 if ( $this->getNamespace() != NS_FILE ) {
4224                         # Remove the upload restriction for non-file titles
4225                         $types = array_diff( $types, array( 'upload' ) );
4226                 }
4227
4228                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4229
4230                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4231                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4232
4233                 return $types;
4234         }
4235         /**
4236          * Get a filtered list of all restriction types supported by this wiki.
4237          * @param bool $exists True to get all restriction types that apply to
4238          * titles that do exist, False for all restriction types that apply to
4239          * titles that do not exist
4240          * @return array
4241          */
4242         public static function getFilteredRestrictionTypes( $exists = true ) {
4243                 global $wgRestrictionTypes;
4244                 $types = $wgRestrictionTypes;
4245                 if ( $exists ) {
4246                         # Remove the create restriction for existing titles
4247                         $types = array_diff( $types, array( 'create' ) );
4248                 } else {
4249                         # Only the create and upload restrictions apply to non-existing titles
4250                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4251                 }
4252                 return $types;
4253         }
4254
4255         /**
4256          * Returns the raw sort key to be used for categories, with the specified
4257          * prefix.  This will be fed to Collation::getSortKey() to get a
4258          * binary sortkey that can be used for actual sorting.
4259          *
4260          * @param $prefix string The prefix to be used, specified using
4261          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4262          *   prefix.
4263          * @return string
4264          */
4265         public function getCategorySortkey( $prefix = '' ) {
4266                 $unprefixed = $this->getText();
4267
4268                 // Anything that uses this hook should only depend
4269                 // on the Title object passed in, and should probably
4270                 // tell the users to run updateCollations.php --force
4271                 // in order to re-sort existing category relations.
4272                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4273                 if ( $prefix !== '' ) {
4274                         # Separate with a line feed, so the unprefixed part is only used as
4275                         # a tiebreaker when two pages have the exact same prefix.
4276                         # In UCA, tab is the only character that can sort above LF
4277                         # so we strip both of them from the original prefix.
4278                         $prefix = strtr( $prefix, "\n\t", '  ' );
4279                         return "$prefix\n$unprefixed";
4280                 }
4281                 return $unprefixed;
4282         }
4283
4284         /**
4285          * Get the language in which the content of this page is written.
4286          * Defaults to $wgContLang, but in certain cases it can be e.g.
4287          * $wgLang (such as special pages, which are in the user language).
4288          *
4289          * @since 1.18
4290          * @return object Language
4291          */
4292         public function getPageLanguage() {
4293                 global $wgLang;
4294                 if ( $this->getNamespace() == NS_SPECIAL ) {
4295                         // special pages are in the user language
4296                         return $wgLang;
4297                 } elseif ( $this->isRedirect() ) {
4298                         // the arrow on a redirect page is aligned according to the user language
4299                         return $wgLang;
4300                 } elseif ( $this->isCssOrJsPage() ) {
4301                         // css/js should always be LTR and is, in fact, English
4302                         return wfGetLangObj( 'en' );
4303                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4304                         // Parse mediawiki messages with correct target language
4305                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4306                         return wfGetLangObj( $lang );
4307                 }
4308                 global $wgContLang;
4309                 // If nothing special, it should be in the wiki content language
4310                 $pageLang = $wgContLang;
4311                 // Hook at the end because we don't want to override the above stuff
4312                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4313                 return wfGetLangObj( $pageLang );
4314         }
4315 }
4316
4317 /**
4318  * A BadTitle is generated in MediaWiki::parseTitle() if the title is invalid; the
4319  * software uses this to display an error page.  Internally it's basically a Title
4320  * for an empty special page
4321  */
4322 class BadTitle extends Title {
4323         public function __construct(){
4324                 $this->mTextform = '';
4325                 $this->mUrlform = '';
4326                 $this->mDbkeyform = '';
4327                 $this->mNamespace = NS_SPECIAL; // Stops talk page link, etc, being shown
4328         }
4329
4330         public function exists(){
4331                 return false;
4332         }
4333
4334         public function getPrefixedText(){
4335                 return '';
4336         }
4337
4338         public function getText(){
4339                 return '';
4340         }
4341
4342         public function getPrefixedURL(){
4343                 return '';
4344         }
4345
4346         public function getPrefixedDBKey(){
4347                 return '';
4348         }
4349 }