includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Represents a title within MediaWiki.
  25  * Optionally may contain an interwiki designation or namespace.
  26  * @note This class can fetch various kinds of data from the database;
  27  *       however, it does so inefficiently.
  28  *
  29  * @internal documentation reviewed 15 Mar 2010
  30  */
  31 class Title {
  32         /** @name Static cache variables */
  33         // @{
  34         static private $titleCache = array();
  35         // @}
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  58         var $mUrlform = '';               // /< URL-encoded form of the main part
  59         var $mDbkeyform = '';             // /< Main part with underscores
  60         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  61         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  62         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  63         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  64         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  65         var $mLatestID = false;           // /< ID of most recent revision
  66         var $mCounter = -1;               // /< Number of times this page has been viewed (-1 means "not loaded")
  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                         if ( isset( $row->page_counter ) )
 277                                 $this->mCounter = (int)$row->page_counter;
 278                 } else { // page not found
 279                         $this->mArticleID = 0;
 280                         $this->mLength = 0;
 281                         $this->mRedirect = false;
 282                         $this->mLatestID = 0;
 283                         $this->mCounter = 0;
 284                 }
 285         }
 286
 287         /**
 288          * Create a new Title from a namespace index and a DB key.
 289          * It's assumed that $ns and $title are *valid*, for instance when
 290          * they came directly from the database or a special page name.
 291          * For convenience, spaces are converted to underscores so that
 292          * eg user_text fields can be used directly.
 293          *
 294          * @param $ns Int the namespace of the article
 295          * @param $title String the unprefixed database key form
 296          * @param $fragment String the link fragment (after the "#")
 297          * @param $interwiki String the interwiki prefix
 298          * @return Title the new object
 299          */
 300         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 301                 $t = new Title();
 302                 $t->mInterwiki = $interwiki;
 303                 $t->mFragment = $fragment;
 304                 $t->mNamespace = $ns = intval( $ns );
 305                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 306                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 307                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 308                 $t->mTextform = str_replace( '_', ' ', $title );
 309                 return $t;
 310         }
 311
 312         /**
 313          * Create a new Title from a namespace index and a DB key.
 314          * The parameters will be checked for validity, which is a bit slower
 315          * than makeTitle() but safer for user-provided data.
 316          *
 317          * @param $ns Int the namespace of the article
 318          * @param $title String database key form
 319          * @param $fragment String the link fragment (after the "#")
 320          * @param $interwiki String interwiki prefix
 321          * @return Title the new object, or NULL on an error
 322          */
 323         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 324                 $t = new Title();
 325                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 326                 if ( $t->secureAndSplit() ) {
 327                         return $t;
 328                 } else {
 329                         return null;
 330                 }
 331         }
 332
 333         /**
 334          * Create a new Title for the Main Page
 335          *
 336          * @return Title the new object
 337          */
 338         public static function newMainPage() {
 339                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 340                 // Don't give fatal errors if the message is broken
 341                 if ( !$title ) {
 342                         $title = Title::newFromText( 'Main Page' );
 343                 }
 344                 return $title;
 345         }
 346
 347         /**
 348          * Extract a redirect destination from a string and return the
 349          * Title, or null if the text doesn't contain a valid redirect
 350          * This will only return the very next target, useful for
 351          * the redirect table and other checks that don't need full recursion
 352          *
 353          * @param $text String: Text with possible redirect
 354          * @return Title: The corresponding Title
 355          */
 356         public static function newFromRedirect( $text ) {
 357                 return self::newFromRedirectInternal( $text );
 358         }
 359
 360         /**
 361          * Extract a redirect destination from a string and return the
 362          * Title, or null if the text doesn't contain a valid redirect
 363          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 364          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 365          *
 366          * @param $text String Text with possible redirect
 367          * @return Title
 368          */
 369         public static function newFromRedirectRecurse( $text ) {
 370                 $titles = self::newFromRedirectArray( $text );
 371                 return $titles ? array_pop( $titles ) : null;
 372         }
 373
 374         /**
 375          * Extract a redirect destination from a string and return an
 376          * array of Titles, or null if the text doesn't contain a valid redirect
 377          * The last element in the array is the final destination after all redirects
 378          * have been resolved (up to $wgMaxRedirects times)
 379          *
 380          * @param $text String Text with possible redirect
 381          * @return Array of Titles, with the destination last
 382          */
 383         public static function newFromRedirectArray( $text ) {
 384                 global $wgMaxRedirects;
 385                 $title = self::newFromRedirectInternal( $text );
 386                 if ( is_null( $title ) ) {
 387                         return null;
 388                 }
 389                 // recursive check to follow double redirects
 390                 $recurse = $wgMaxRedirects;
 391                 $titles = array( $title );
 392                 while ( --$recurse > 0 ) {
 393                         if ( $title->isRedirect() ) {
 394                                 $page = WikiPage::factory( $title );
 395                                 $newtitle = $page->getRedirectTarget();
 396                         } else {
 397                                 break;
 398                         }
 399                         // Redirects to some special pages are not permitted
 400                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 401                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 402                                 $title = $newtitle;
 403                                 $titles[] = $newtitle;
 404                         } else {
 405                                 break;
 406                         }
 407                 }
 408                 return $titles;
 409         }
 410
 411         /**
 412          * Really extract the redirect destination
 413          * Do not call this function directly, use one of the newFromRedirect* functions above
 414          *
 415          * @param $text String Text with possible redirect
 416          * @return Title
 417          */
 418         protected static function newFromRedirectInternal( $text ) {
 419                 global $wgMaxRedirects;
 420                 if ( $wgMaxRedirects < 1 ) {
 421                         //redirects are disabled, so quit early
 422                         return null;
 423                 }
 424                 $redir = MagicWord::get( 'redirect' );
 425                 $text = trim( $text );
 426                 if ( $redir->matchStartAndRemove( $text ) ) {
 427                         // Extract the first link and see if it's usable
 428                         // Ensure that it really does come directly after #REDIRECT
 429                         // Some older redirects included a colon, so don't freak about that!
 430                         $m = array();
 431                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 432                                 // Strip preceding colon used to "escape" categories, etc.
 433                                 // and URL-decode links
 434                                 if ( strpos( $m[1], '%' ) !== false ) {
 435                                         // Match behavior of inline link parsing here;
 436                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 437                                 }
 438                                 $title = Title::newFromText( $m[1] );
 439                                 // If the title is a redirect to bad special pages or is invalid, return null
 440                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 441                                         return null;
 442                                 }
 443                                 return $title;
 444                         }
 445                 }
 446                 return null;
 447         }
 448
 449         /**
 450          * Get the prefixed DB key associated with an ID
 451          *
 452          * @param $id Int the page_id of the article
 453          * @return Title an object representing the article, or NULL if no such article was found
 454          */
 455         public static function nameOf( $id ) {
 456                 $dbr = wfGetDB( DB_SLAVE );
 457
 458                 $s = $dbr->selectRow(
 459                         'page',
 460                         array( 'page_namespace', 'page_title' ),
 461                         array( 'page_id' => $id ),
 462                         __METHOD__
 463                 );
 464                 if ( $s === false ) {
 465                         return null;
 466                 }
 467
 468                 $n = self::makeName( $s->page_namespace, $s->page_title );
 469                 return $n;
 470         }
 471
 472         /**
 473          * Get a regex character class describing the legal characters in a link
 474          *
 475          * @return String the list of characters, not delimited
 476          */
 477         public static function legalChars() {
 478                 global $wgLegalTitleChars;
 479                 return $wgLegalTitleChars;
 480         }
 481
 482         /**
 483          * Returns a simple regex that will match on characters and sequences invalid in titles.
 484          * Note that this doesn't pick up many things that could be wrong with titles, but that
 485          * replacing this regex with something valid will make many titles valid.
 486          *
 487          * @return String regex string
 488          */
 489         static function getTitleInvalidRegex() {
 490                 static $rxTc = false;
 491                 if ( !$rxTc ) {
 492                         # Matching titles will be held as illegal.
 493                         $rxTc = '/' .
 494                                 # Any character not allowed is forbidden...
 495                                 '[^' . self::legalChars() . ']' .
 496                                 # URL percent encoding sequences interfere with the ability
 497                                 # to round-trip titles -- you can't link to them consistently.
 498                                 '|%[0-9A-Fa-f]{2}' .
 499                                 # XML/HTML character references produce similar issues.
 500                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 501                                 '|&#[0-9]+;' .
 502                                 '|&#x[0-9A-Fa-f]+;' .
 503                                 '/S';
 504                 }
 505
 506                 return $rxTc;
 507         }
 508
 509         /**
 510          * Get a string representation of a title suitable for
 511          * including in a search index
 512          *
 513          * @param $ns Int a namespace index
 514          * @param $title String text-form main part
 515          * @return String a stripped-down title string ready for the search index
 516          */
 517         public static function indexTitle( $ns, $title ) {
 518                 global $wgContLang;
 519
 520                 $lc = SearchEngine::legalSearchChars() . '&#;';
 521                 $t = $wgContLang->normalizeForSearch( $title );
 522                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 523                 $t = $wgContLang->lc( $t );
 524
 525                 # Handle 's, s'
 526                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 527                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 528
 529                 $t = preg_replace( "/\\s+/", ' ', $t );
 530
 531                 if ( $ns == NS_FILE ) {
 532                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 533                 }
 534                 return trim( $t );
 535         }
 536
 537         /**
 538          * Make a prefixed DB key from a DB key and a namespace index
 539          *
 540          * @param $ns Int numerical representation of the namespace
 541          * @param $title String the DB key form the title
 542          * @param $fragment String The link fragment (after the "#")
 543          * @param $interwiki String The interwiki prefix
 544          * @return String the prefixed form of the title
 545          */
 546         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 547                 global $wgContLang;
 548
 549                 $namespace = $wgContLang->getNsText( $ns );
 550                 $name = $namespace == '' ? $title : "$namespace:$title";
 551                 if ( strval( $interwiki ) != '' ) {
 552                         $name = "$interwiki:$name";
 553                 }
 554                 if ( strval( $fragment ) != '' ) {
 555                         $name .= '#' . $fragment;
 556                 }
 557                 return $name;
 558         }
 559
 560         /**
 561          * Escape a text fragment, say from a link, for a URL
 562          *
 563          * @param $fragment string containing a URL or link fragment (after the "#")
 564          * @return String: escaped string
 565          */
 566         static function escapeFragmentForURL( $fragment ) {
 567                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 568                 # fragments appear not to work in IE (at least up to 7) or in at least
 569                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 570                 # to care if they aren't encoded.
 571                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 572         }
 573
 574         /**
 575          * Callback for usort() to do title sorts by (namespace, title)
 576          *
 577          * @param $a Title
 578          * @param $b Title
 579          *
 580          * @return Integer: result of string comparison, or namespace comparison
 581          */
 582         public static function compare( $a, $b ) {
 583                 if ( $a->getNamespace() == $b->getNamespace() ) {
 584                         return strcmp( $a->getText(), $b->getText() );
 585                 } else {
 586                         return $a->getNamespace() - $b->getNamespace();
 587                 }
 588         }
 589
 590         /**
 591          * Determine whether the object refers to a page within
 592          * this project.
 593          *
 594          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 595          */
 596         public function isLocal() {
 597                 if ( $this->mInterwiki != '' ) {
 598                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 599                 } else {
 600                         return true;
 601                 }
 602         }
 603
 604         /**
 605          * Is this Title interwiki?
 606          *
 607          * @return Bool
 608          */
 609         public function isExternal() {
 610                 return ( $this->mInterwiki != '' );
 611         }
 612
 613         /**
 614          * Get the interwiki prefix (or null string)
 615          *
 616          * @return String Interwiki prefix
 617          */
 618         public function getInterwiki() {
 619                 return $this->mInterwiki;
 620         }
 621
 622         /**
 623          * Determine whether the object refers to a page within
 624          * this project and is transcludable.
 625          *
 626          * @return Bool TRUE if this is transcludable
 627          */
 628         public function isTrans() {
 629                 if ( $this->mInterwiki == '' ) {
 630                         return false;
 631                 }
 632
 633                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 634         }
 635
 636         /**
 637          * Returns the DB name of the distant wiki which owns the object.
 638          *
 639          * @return String the DB name
 640          */
 641         public function getTransWikiID() {
 642                 if ( $this->mInterwiki == '' ) {
 643                         return false;
 644                 }
 645
 646                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 647         }
 648
 649         /**
 650          * Get the text form (spaces not underscores) of the main part
 651          *
 652          * @return String Main part of the title
 653          */
 654         public function getText() {
 655                 return $this->mTextform;
 656         }
 657
 658         /**
 659          * Get the URL-encoded form of the main part
 660          *
 661          * @return String Main part of the title, URL-encoded
 662          */
 663         public function getPartialURL() {
 664                 return $this->mUrlform;
 665         }
 666
 667         /**
 668          * Get the main part with underscores
 669          *
 670          * @return String: Main part of the title, with underscores
 671          */
 672         public function getDBkey() {
 673                 return $this->mDbkeyform;
 674         }
 675
 676         /**
 677          * Get the DB key with the initial letter case as specified by the user
 678          *
 679          * @return String DB key
 680          */
 681         function getUserCaseDBKey() {
 682                 return $this->mUserCaseDBKey;
 683         }
 684
 685         /**
 686          * Get the namespace index, i.e. one of the NS_xxxx constants.
 687          *
 688          * @return Integer: Namespace index
 689          */
 690         public function getNamespace() {
 691                 return $this->mNamespace;
 692         }
 693
 694         /**
 695          * Get the namespace text
 696          *
 697          * @return String: Namespace text
 698          */
 699         public function getNsText() {
 700                 global $wgContLang;
 701
 702                 if ( $this->mInterwiki != '' ) {
 703                         // This probably shouldn't even happen. ohh man, oh yuck.
 704                         // But for interwiki transclusion it sometimes does.
 705                         // Shit. Shit shit shit.
 706                         //
 707                         // Use the canonical namespaces if possible to try to
 708                         // resolve a foreign namespace.
 709                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 710                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 711                         }
 712                 }
 713
 714                 // Strip off subpages
 715                 $pagename = $this->getText();
 716                 if ( strpos( $pagename, '/' ) !== false ) {
 717                         list( $username , ) = explode( '/', $pagename, 2 );
 718                 } else {
 719                         $username = $pagename;
 720                 }
 721
 722                 if ( $wgContLang->needsGenderDistinction() &&
 723                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 724                         $gender = GenderCache::singleton()->getGenderOf( $username, __METHOD__ );
 725                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 726                 }
 727
 728                 return $wgContLang->getNsText( $this->mNamespace );
 729         }
 730
 731         /**
 732          * Get the namespace text of the subject (rather than talk) page
 733          *
 734          * @return String Namespace text
 735          */
 736         public function getSubjectNsText() {
 737                 global $wgContLang;
 738                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 739         }
 740
 741         /**
 742          * Get the namespace text of the talk page
 743          *
 744          * @return String Namespace text
 745          */
 746         public function getTalkNsText() {
 747                 global $wgContLang;
 748                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 749         }
 750
 751         /**
 752          * Could this title have a corresponding talk page?
 753          *
 754          * @return Bool TRUE or FALSE
 755          */
 756         public function canTalk() {
 757                 return( MWNamespace::canTalk( $this->mNamespace ) );
 758         }
 759
 760         /**
 761          * Is this in a namespace that allows actual pages?
 762          *
 763          * @return Bool
 764          * @internal note -- uses hardcoded namespace index instead of constants
 765          */
 766         public function canExist() {
 767                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
 768         }
 769
 770         /**
 771          * Can this title be added to a user's watchlist?
 772          *
 773          * @return Bool TRUE or FALSE
 774          */
 775         public function isWatchable() {
 776                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 777         }
 778
 779         /**
 780          * Returns true if this is a special page.
 781          *
 782          * @return boolean
 783          */
 784         public function isSpecialPage() {
 785                 return $this->getNamespace() == NS_SPECIAL;
 786         }
 787
 788         /**
 789          * Returns true if this title resolves to the named special page
 790          *
 791          * @param $name String The special page name
 792          * @return boolean
 793          */
 794         public function isSpecial( $name ) {
 795                 if ( $this->isSpecialPage() ) {
 796                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 797                         if ( $name == $thisName ) {
 798                                 return true;
 799                         }
 800                 }
 801                 return false;
 802         }
 803
 804         /**
 805          * If the Title refers to a special page alias which is not the local default, resolve
 806          * the alias, and localise the name as necessary.  Otherwise, return $this
 807          *
 808          * @return Title
 809          */
 810         public function fixSpecialName() {
 811                 if ( $this->isSpecialPage() ) {
 812                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 813                         if ( $canonicalName ) {
 814                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 815                                 if ( $localName != $this->mDbkeyform ) {
 816                                         return Title::makeTitle( NS_SPECIAL, $localName );
 817                                 }
 818                         }
 819                 }
 820                 return $this;
 821         }
 822
 823         /**
 824          * Returns true if the title is inside the specified namespace.
 825          *
 826          * Please make use of this instead of comparing to getNamespace()
 827          * This function is much more resistant to changes we may make
 828          * to namespaces than code that makes direct comparisons.
 829          * @param $ns int The namespace
 830          * @return bool
 831          * @since 1.19
 832          */
 833         public function inNamespace( $ns ) {
 834                 return MWNamespace::equals( $this->getNamespace(), $ns );
 835         }
 836
 837         /**
 838          * Returns true if the title is inside one of the specified namespaces.
 839          *
 840          * @param ...$namespaces The namespaces to check for
 841          * @return bool
 842          * @since 1.19
 843          */
 844         public function inNamespaces( /* ... */ ) {
 845                 $namespaces = func_get_args();
 846                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 847                         $namespaces = $namespaces[0];
 848                 }
 849
 850                 foreach ( $namespaces as $ns ) {
 851                         if ( $this->inNamespace( $ns ) ) {
 852                                 return true;
 853                         }
 854                 }
 855
 856                 return false;
 857         }
 858
 859         /**
 860          * Returns true if the title has the same subject namespace as the
 861          * namespace specified.
 862          * For example this method will take NS_USER and return true if namespace
 863          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 864          * as their subject namespace.
 865          *
 866          * This is MUCH simpler than individually testing for equivilance
 867          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 868          * @since 1.19
 869          */
 870         public function hasSubjectNamespace( $ns ) {
 871                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 872         }
 873
 874         /**
 875          * Is this Title in a namespace which contains content?
 876          * In other words, is this a content page, for the purposes of calculating
 877          * statistics, etc?
 878          *
 879          * @return Boolean
 880          */
 881         public function isContentPage() {
 882                 return MWNamespace::isContent( $this->getNamespace() );
 883         }
 884
 885         /**
 886          * Would anybody with sufficient privileges be able to move this page?
 887          * Some pages just aren't movable.
 888          *
 889          * @return Bool TRUE or FALSE
 890          */
 891         public function isMovable() {
 892                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 893                         // Interwiki title or immovable namespace. Hooks don't get to override here
 894                         return false;
 895                 }
 896
 897                 $result = true;
 898                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 899                 return $result;
 900         }
 901
 902         /**
 903          * Is this the mainpage?
 904          * @note Title::newFromText seams to be sufficiently optimized by the title
 905          * cache that we don't need to over-optimize by doing direct comparisons and
 906          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 907          * ends up reporting something differently than $title->isMainPage();
 908          *
 909          * @since 1.18
 910          * @return Bool
 911          */
 912         public function isMainPage() {
 913                 return $this->equals( Title::newMainPage() );
 914         }
 915
 916         /**
 917          * Is this a subpage?
 918          *
 919          * @return Bool
 920          */
 921         public function isSubpage() {
 922                 return MWNamespace::hasSubpages( $this->mNamespace )
 923                         ? strpos( $this->getText(), '/' ) !== false
 924                         : false;
 925         }
 926
 927         /**
 928          * Is this a conversion table for the LanguageConverter?
 929          *
 930          * @return Bool
 931          */
 932         public function isConversionTable() {
 933                 return $this->getNamespace() == NS_MEDIAWIKI &&
 934                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 935         }
 936
 937         /**
 938          * Does that page contain wikitext, or it is JS, CSS or whatever?
 939          *
 940          * @return Bool
 941          */
 942         public function isWikitextPage() {
 943                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
 944                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
 945                 return $retval;
 946         }
 947
 948         /**
 949          * Could this page contain custom CSS or JavaScript, based
 950          * on the title?
 951          *
 952          * @return Bool
 953          */
 954         public function isCssOrJsPage() {
 955                 $retval = $this->mNamespace == NS_MEDIAWIKI
 956                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
 957                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
 958                 return $retval;
 959         }
 960
 961         /**
 962          * Is this a .css or .js subpage of a user page?
 963          * @return Bool
 964          */
 965         public function isCssJsSubpage() {
 966                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
 967         }
 968
 969         /**
 970          * Is this a *valid* .css or .js subpage of a user page?
 971          *
 972          * @return Bool
 973          * @deprecated since 1.17
 974          */
 975         public function isValidCssJsSubpage() {
 976                 return $this->isCssJsSubpage();
 977         }
 978
 979         /**
 980          * Trim down a .css or .js subpage title to get the corresponding skin name
 981          *
 982          * @return string containing skin name from .css or .js subpage title
 983          */
 984         public function getSkinFromCssJsSubpage() {
 985                 $subpage = explode( '/', $this->mTextform );
 986                 $subpage = $subpage[ count( $subpage ) - 1 ];
 987                 $lastdot = strrpos( $subpage, '.' );
 988                 if ( $lastdot === false )
 989                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 990                 return substr( $subpage, 0, $lastdot );
 991         }
 992
 993         /**
 994          * Is this a .css subpage of a user page?
 995          *
 996          * @return Bool
 997          */
 998         public function isCssSubpage() {
 999                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1000         }
1001
1002         /**
1003          * Is this a .js subpage of a user page?
1004          *
1005          * @return Bool
1006          */
1007         public function isJsSubpage() {
1008                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1009         }
1010
1011         /**
1012          * Is this a talk page of some sort?
1013          *
1014          * @return Bool
1015          */
1016         public function isTalkPage() {
1017                 return MWNamespace::isTalk( $this->getNamespace() );
1018         }
1019
1020         /**
1021          * Get a Title object associated with the talk page of this article
1022          *
1023          * @return Title the object for the talk page
1024          */
1025         public function getTalkPage() {
1026                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1027         }
1028
1029         /**
1030          * Get a title object associated with the subject page of this
1031          * talk page
1032          *
1033          * @return Title the object for the subject page
1034          */
1035         public function getSubjectPage() {
1036                 // Is this the same title?
1037                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1038                 if ( $this->getNamespace() == $subjectNS ) {
1039                         return $this;
1040                 }
1041                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1042         }
1043
1044         /**
1045          * Get the default namespace index, for when there is no namespace
1046          *
1047          * @return Int Default namespace index
1048          */
1049         public function getDefaultNamespace() {
1050                 return $this->mDefaultNamespace;
1051         }
1052
1053         /**
1054          * Get title for search index
1055          *
1056          * @return String a stripped-down title string ready for the
1057          *  search index
1058          */
1059         public function getIndexTitle() {
1060                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1061         }
1062
1063         /**
1064          * Get the Title fragment (i.e.\ the bit after the #) in text form
1065          *
1066          * @return String Title fragment
1067          */
1068         public function getFragment() {
1069                 return $this->mFragment;
1070         }
1071
1072         /**
1073          * Get the fragment in URL form, including the "#" character if there is one
1074          * @return String Fragment in URL form
1075          */
1076         public function getFragmentForURL() {
1077                 if ( $this->mFragment == '' ) {
1078                         return '';
1079                 } else {
1080                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1081                 }
1082         }
1083
1084         /**
1085          * Set the fragment for this title. Removes the first character from the
1086          * specified fragment before setting, so it assumes you're passing it with
1087          * an initial "#".
1088          *
1089          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1090          * Still in active use privately.
1091          *
1092          * @param $fragment String text
1093          */
1094         public function setFragment( $fragment ) {
1095                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1096         }
1097
1098         /**
1099          * Prefix some arbitrary text with the namespace or interwiki prefix
1100          * of this object
1101          *
1102          * @param $name String the text
1103          * @return String the prefixed text
1104          * @private
1105          */
1106         private function prefix( $name ) {
1107                 $p = '';
1108                 if ( $this->mInterwiki != '' ) {
1109                         $p = $this->mInterwiki . ':';
1110                 }
1111
1112                 if ( 0 != $this->mNamespace ) {
1113                         $p .= $this->getNsText() . ':';
1114                 }
1115                 return $p . $name;
1116         }
1117
1118         /**
1119          * Get the prefixed database key form
1120          *
1121          * @return String the prefixed title, with underscores and
1122          *  any interwiki and namespace prefixes
1123          */
1124         public function getPrefixedDBkey() {
1125                 $s = $this->prefix( $this->mDbkeyform );
1126                 $s = str_replace( ' ', '_', $s );
1127                 return $s;
1128         }
1129
1130         /**
1131          * Get the prefixed title with spaces.
1132          * This is the form usually used for display
1133          *
1134          * @return String the prefixed title, with spaces
1135          */
1136         public function getPrefixedText() {
1137                 // @todo FIXME: Bad usage of empty() ?
1138                 if ( empty( $this->mPrefixedText ) ) {
1139                         $s = $this->prefix( $this->mTextform );
1140                         $s = str_replace( '_', ' ', $s );
1141                         $this->mPrefixedText = $s;
1142                 }
1143                 return $this->mPrefixedText;
1144         }
1145
1146         /**
1147          * Return a string representation of this title
1148          *
1149          * @return String representation of this title
1150          */
1151         public function __toString() {
1152                 return $this->getPrefixedText();
1153         }
1154
1155         /**
1156          * Get the prefixed title with spaces, plus any fragment
1157          * (part beginning with '#')
1158          *
1159          * @return String the prefixed title, with spaces and the fragment, including '#'
1160          */
1161         public function getFullText() {
1162                 $text = $this->getPrefixedText();
1163                 if ( $this->mFragment != '' ) {
1164                         $text .= '#' . $this->mFragment;
1165                 }
1166                 return $text;
1167         }
1168
1169         /**
1170          * Get the base page name, i.e. the leftmost part before any slashes
1171          *
1172          * @return String Base name
1173          */
1174         public function getBaseText() {
1175                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1176                         return $this->getText();
1177                 }
1178
1179                 $parts = explode( '/', $this->getText() );
1180                 # Don't discard the real title if there's no subpage involved
1181                 if ( count( $parts ) > 1 ) {
1182                         unset( $parts[count( $parts ) - 1] );
1183                 }
1184                 return implode( '/', $parts );
1185         }
1186
1187         /**
1188          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1189          *
1190          * @return String Subpage name
1191          */
1192         public function getSubpageText() {
1193                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1194                         return( $this->mTextform );
1195                 }
1196                 $parts = explode( '/', $this->mTextform );
1197                 return( $parts[count( $parts ) - 1] );
1198         }
1199
1200         /**
1201          * Get the HTML-escaped displayable text form.
1202          * Used for the title field in <a> tags.
1203          *
1204          * @return String the text, including any prefixes
1205          */
1206         public function getEscapedText() {
1207                 return htmlspecialchars( $this->getPrefixedText() );
1208         }
1209
1210         /**
1211          * Get a URL-encoded form of the subpage text
1212          *
1213          * @return String URL-encoded subpage name
1214          */
1215         public function getSubpageUrlForm() {
1216                 $text = $this->getSubpageText();
1217                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1218                 return( $text );
1219         }
1220
1221         /**
1222          * Get a URL-encoded title (not an actual URL) including interwiki
1223          *
1224          * @return String the URL-encoded form
1225          */
1226         public function getPrefixedURL() {
1227                 $s = $this->prefix( $this->mDbkeyform );
1228                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1229                 return $s;
1230         }
1231
1232         /**
1233          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1234          */
1235         private static function fixUrlQueryArgs( $query, $query2 ) {
1236                 if ( is_array( $query ) ) {
1237                         $query = wfArrayToCGI( $query );
1238                 }
1239                 if ( $query2 ) {
1240                         if ( is_string( $query2 ) ) {
1241                                 // $query2 is a string, we will consider this to be
1242                                 // a deprecated $variant argument and add it to the query
1243                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1244                         } else {
1245                                 $query2 = wfArrayToCGI( $query2 );
1246                         }
1247                         // If we have $query content add a & to it first
1248                         if ( $query ) {
1249                                 $query .= '&';
1250                         }
1251                         // Now append the queries together
1252                         $query .= $query2;
1253                 }
1254                 return $query;
1255         }
1256
1257         /**
1258          * Get a real URL referring to this title, with interwiki link and
1259          * fragment
1260          *
1261          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
1262          *   links. Can be specified as an associative array as well, e.g.,
1263          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1264          * @param $variant String language variant of url (for sr, zh..)
1265          * @return String the URL
1266          */
1267         public function getFullURL( $query = '', $query2 = false ) {
1268                 $query = self::fixUrlQueryArgs( $query, $query2 );
1269
1270                 # Hand off all the decisions on urls to getLocalURL
1271                 $url = $this->getLocalURL( $query );
1272
1273                 # Expand the url to make it a full url. Note that getLocalURL has the
1274                 # potential to output full urls for a variety of reasons, so we use
1275                 # wfExpandUrl instead of simply prepending $wgServer
1276                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1277
1278                 # Finally, add the fragment.
1279                 $url .= $this->getFragmentForURL();
1280
1281                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1282                 return $url;
1283         }
1284
1285         /**
1286          * Get a URL with no fragment or server name.  If this page is generated
1287          * with action=render, $wgServer is prepended.
1288          *
1289          * @param $query Mixed: an optional query string; if not specified,
1290          *   $wgArticlePath will be used.  Can be specified as an associative array
1291          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
1292          *   URL-escaped).
1293          * @param $variant String language variant of url (for sr, zh..)
1294          * @return String the URL
1295          */
1296         public function getLocalURL( $query = '', $query2 = false ) {
1297                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1298
1299                 $query = self::fixUrlQueryArgs( $query, $query2 );
1300
1301                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1302                 if ( $interwiki ) {
1303                         $namespace = $this->getNsText();
1304                         if ( $namespace != '' ) {
1305                                 # Can this actually happen? Interwikis shouldn't be parsed.
1306                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1307                                 $namespace .= ':';
1308                         }
1309                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1310                         $url = wfAppendQuery( $url, $query );
1311                 } else {
1312                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1313                         if ( $query == '' ) {
1314                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1315                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1316                         } else {
1317                                 global $wgVariantArticlePath, $wgActionPaths;
1318                                 $url = false;
1319                                 $matches = array();
1320
1321                                 if ( !empty( $wgActionPaths ) &&
1322                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1323                                 {
1324                                         $action = urldecode( $matches[2] );
1325                                         if ( isset( $wgActionPaths[$action] ) ) {
1326                                                 $query = $matches[1];
1327                                                 if ( isset( $matches[4] ) ) {
1328                                                         $query .= $matches[4];
1329                                                 }
1330                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1331                                                 if ( $query != '' ) {
1332                                                         $url = wfAppendQuery( $url, $query );
1333                                                 }
1334                                         }
1335                                 }
1336
1337                                 if ( $url === false &&
1338                                         $wgVariantArticlePath &&
1339                                         $this->getPageLanguage()->hasVariants() &&
1340                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1341                                 {
1342                                         $variant = urldecode( $matches[1] );
1343                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1344                                                 // Only do the variant replacement if the given variant is a valid
1345                                                 // variant for the page's language.
1346                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1347                                                 $url = str_replace( '$1', $dbkey, $url );
1348                                         }
1349                                 }
1350
1351                                 if ( $url === false ) {
1352                                         if ( $query == '-' ) {
1353                                                 $query = '';
1354                                         }
1355                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1356                                 }
1357                         }
1358
1359                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1360
1361                         // @todo FIXME: This causes breakage in various places when we
1362                         // actually expected a local URL and end up with dupe prefixes.
1363                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1364                                 $url = $wgServer . $url;
1365                         }
1366                 }
1367                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1368                 return $url;
1369         }
1370
1371         /**
1372          * Get a URL that's the simplest URL that will be valid to link, locally,
1373          * to the current Title.  It includes the fragment, but does not include
1374          * the server unless action=render is used (or the link is external).  If
1375          * there's a fragment but the prefixed text is empty, we just return a link
1376          * to the fragment.
1377          *
1378          * The result obviously should not be URL-escaped, but does need to be
1379          * HTML-escaped if it's being output in HTML.
1380          *
1381          * @param $query Array of Strings An associative array of key => value pairs for the
1382          *   query string.  Keys and values will be escaped.
1383          * @param $variant String language variant of URL (for sr, zh..).  Ignored
1384          *   for external links.  Default is "false" (same variant as current page,
1385          *   for anonymous users).
1386          * @return String the URL
1387          */
1388         public function getLinkURL( $query = '', $query2 = false ) {
1389                 wfProfileIn( __METHOD__ );
1390                 if ( $this->isExternal() ) {
1391                         $ret = $this->getFullURL( $query, $query2 );
1392                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1393                         $ret = $this->getFragmentForURL();
1394                 } else {
1395                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1396                 }
1397                 wfProfileOut( __METHOD__ );
1398                 return $ret;
1399         }
1400
1401         /**
1402          * Get an HTML-escaped version of the URL form, suitable for
1403          * using in a link, without a server name or fragment
1404          *
1405          * @param $query String an optional query string
1406          * @return String the URL
1407          */
1408         public function escapeLocalURL( $query = '', $query2 = false ) {
1409                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1410         }
1411
1412         /**
1413          * Get an HTML-escaped version of the URL form, suitable for
1414          * using in a link, including the server name and fragment
1415          *
1416          * @param $query String an optional query string
1417          * @return String the URL
1418          */
1419         public function escapeFullURL( $query = '', $query2 = false ) {
1420                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1421         }
1422
1423         /**
1424          * Get the URL form for an internal link.
1425          * - Used in various Squid-related code, in case we have a different
1426          * internal hostname for the server from the exposed one.
1427          *
1428          * This uses $wgInternalServer to qualify the path, or $wgServer
1429          * if $wgInternalServer is not set. If the server variable used is
1430          * protocol-relative, the URL will be expanded to http://
1431          *
1432          * @param $query String an optional query string
1433          * @param $variant String language variant of url (for sr, zh..)
1434          * @return String the URL
1435          */
1436         public function getInternalURL( $query = '', $query2 = false ) {
1437                 global $wgInternalServer, $wgServer;
1438                 $query = self::fixUrlQueryArgs( $query, $query2 );
1439                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1440                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1441                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1442                 return $url;
1443         }
1444
1445         /**
1446          * Get the URL for a canonical link, for use in things like IRC and
1447          * e-mail notifications. Uses $wgCanonicalServer and the
1448          * GetCanonicalURL hook.
1449          *
1450          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1451          *
1452          * @param $query string An optional query string
1453          * @param $variant string Language variant of URL (for sr, zh, ...)
1454          * @return string The URL
1455          * @since 1.18
1456          */
1457         public function getCanonicalURL( $query = '', $query2 = false ) {
1458                 $query = self::fixUrlQueryArgs( $query, $query2 );
1459                 $url = wfExpandUrl( $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1460                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1461                 return $url;
1462         }
1463
1464         /**
1465          * HTML-escaped version of getCanonicalURL()
1466          * @since 1.18
1467          */
1468         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1469                 wfDeprecated( __METHOD__, '1.19' );
1470                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1471         }
1472
1473         /**
1474          * Get the edit URL for this Title
1475          *
1476          * @return String the URL, or a null string if this is an
1477          *  interwiki link
1478          */
1479         public function getEditURL() {
1480                 if ( $this->mInterwiki != '' ) {
1481                         return '';
1482                 }
1483                 $s = $this->getLocalURL( 'action=edit' );
1484
1485                 return $s;
1486         }
1487
1488         /**
1489          * Is $wgUser watching this page?
1490          *
1491          * @return Bool
1492          */
1493         public function userIsWatching() {
1494                 global $wgUser;
1495
1496                 if ( is_null( $this->mWatched ) ) {
1497                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1498                                 $this->mWatched = false;
1499                         } else {
1500                                 $this->mWatched = $wgUser->isWatched( $this );
1501                         }
1502                 }
1503                 return $this->mWatched;
1504         }
1505
1506         /**
1507          * Can $wgUser read this page?
1508          *
1509          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1510          * @return Bool
1511          * @todo fold these checks into userCan()
1512          */
1513         public function userCanRead() {
1514                 return $this->userCan( 'read' );
1515         }
1516
1517         /**
1518          * Can $user perform $action on this page?
1519          * This skips potentially expensive cascading permission checks
1520          * as well as avoids expensive error formatting
1521          *
1522          * Suitable for use for nonessential UI controls in common cases, but
1523          * _not_ for functional access control.
1524          *
1525          * May provide false positives, but should never provide a false negative.
1526          *
1527          * @param $action String action that permission needs to be checked for
1528          * @param $user User to check (since 1.19); $wgUser will be used if not
1529          *              provided.
1530          * @return Bool
1531          */
1532         public function quickUserCan( $action, $user = null ) {
1533                 return $this->userCan( $action, $user, false );
1534         }
1535
1536         /**
1537          * Can $user perform $action on this page?
1538          *
1539          * @param $action String action that permission needs to be checked for
1540          * @param $user User to check (since 1.19); $wgUser will be used if not
1541          *   provided.
1542          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1543          *   unnecessary queries.
1544          * @return Bool
1545          */
1546         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1547                 if ( !$user instanceof User ) {
1548                         global $wgUser;
1549                         $user = $wgUser;
1550                 }
1551                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1552         }
1553
1554         /**
1555          * Can $user perform $action on this page?
1556          *
1557          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1558          *
1559          * @param $action String action that permission needs to be checked for
1560          * @param $user User to check
1561          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1562          *   queries by skipping checks for cascading protections and user blocks.
1563          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1564          *   whose corresponding errors may be ignored.
1565          * @return Array of arguments to wfMsg to explain permissions problems.
1566          */
1567         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1568                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1569
1570                 // Remove the errors being ignored.
1571                 foreach ( $errors as $index => $error ) {
1572                         $error_key = is_array( $error ) ? $error[0] : $error;
1573
1574                         if ( in_array( $error_key, $ignoreErrors ) ) {
1575                                 unset( $errors[$index] );
1576                         }
1577                 }
1578
1579                 return $errors;
1580         }
1581
1582         /**
1583          * Permissions checks that fail most often, and which are easiest to test.
1584          *
1585          * @param $action String the action to check
1586          * @param $user User user to check
1587          * @param $errors Array list of current errors
1588          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1589          * @param $short Boolean short circuit on first error
1590          *
1591          * @return Array list of errors
1592          */
1593         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1594                 if ( $action == 'create' ) {
1595                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1596                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1597                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1598                         }
1599                 } elseif ( $action == 'move' ) {
1600                         if ( !$user->isAllowed( 'move-rootuserpages' )
1601                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1602                                 // Show user page-specific message only if the user can move other pages
1603                                 $errors[] = array( 'cant-move-user-page' );
1604                         }
1605
1606                         // Check if user is allowed to move files if it's a file
1607                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1608                                 $errors[] = array( 'movenotallowedfile' );
1609                         }
1610
1611                         if ( !$user->isAllowed( 'move' ) ) {
1612                                 // User can't move anything
1613                                 global $wgGroupPermissions;
1614                                 $userCanMove = false;
1615                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1616                                         $userCanMove = $wgGroupPermissions['user']['move'];
1617                                 }
1618                                 $autoconfirmedCanMove = false;
1619                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1620                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1621                                 }
1622                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1623                                         // custom message if logged-in users without any special rights can move
1624                                         $errors[] = array( 'movenologintext' );
1625                                 } else {
1626                                         $errors[] = array( 'movenotallowed' );
1627                                 }
1628                         }
1629                 } elseif ( $action == 'move-target' ) {
1630                         if ( !$user->isAllowed( 'move' ) ) {
1631                                 // User can't move anything
1632                                 $errors[] = array( 'movenotallowed' );
1633                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1634                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1635                                 // Show user page-specific message only if the user can move other pages
1636                                 $errors[] = array( 'cant-move-to-user-page' );
1637                         }
1638                 } elseif ( !$user->isAllowed( $action ) ) {
1639                         $errors[] = $this->missingPermissionError( $action, $short );
1640                 }
1641
1642                 return $errors;
1643         }
1644
1645         /**
1646          * Add the resulting error code to the errors array
1647          *
1648          * @param $errors Array list of current errors
1649          * @param $result Mixed result of errors
1650          *
1651          * @return Array list of errors
1652          */
1653         private function resultToError( $errors, $result ) {
1654                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1655                         // A single array representing an error
1656                         $errors[] = $result;
1657                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1658                         // A nested array representing multiple errors
1659                         $errors = array_merge( $errors, $result );
1660                 } elseif ( $result !== '' && is_string( $result ) ) {
1661                         // A string representing a message-id
1662                         $errors[] = array( $result );
1663                 } elseif ( $result === false ) {
1664                         // a generic "We don't want them to do that"
1665                         $errors[] = array( 'badaccess-group0' );
1666                 }
1667                 return $errors;
1668         }
1669
1670         /**
1671          * Check various permission hooks
1672          *
1673          * @param $action String the action to check
1674          * @param $user User user to check
1675          * @param $errors Array list of current errors
1676          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1677          * @param $short Boolean short circuit on first error
1678          *
1679          * @return Array list of errors
1680          */
1681         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1682                 // Use getUserPermissionsErrors instead
1683                 $result = '';
1684                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1685                         return $result ? array() : array( array( 'badaccess-group0' ) );
1686                 }
1687                 // Check getUserPermissionsErrors hook
1688                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1689                         $errors = $this->resultToError( $errors, $result );
1690                 }
1691                 // Check getUserPermissionsErrorsExpensive hook
1692                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1693                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1694                         $errors = $this->resultToError( $errors, $result );
1695                 }
1696
1697                 return $errors;
1698         }
1699
1700         /**
1701          * Check permissions on special pages & namespaces
1702          *
1703          * @param $action String the action to check
1704          * @param $user User user to check
1705          * @param $errors Array list of current errors
1706          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1707          * @param $short Boolean short circuit on first error
1708          *
1709          * @return Array list of errors
1710          */
1711         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1712                 # Only 'createaccount' and 'execute' can be performed on
1713                 # special pages, which don't actually exist in the DB.
1714                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1715                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1716                         $errors[] = array( 'ns-specialprotected' );
1717                 }
1718
1719                 # Check $wgNamespaceProtection for restricted namespaces
1720                 if ( $this->isNamespaceProtected( $user ) ) {
1721                         $ns = $this->mNamespace == NS_MAIN ?
1722                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1723                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1724                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1725                 }
1726
1727                 return $errors;
1728         }
1729
1730         /**
1731          * Check CSS/JS sub-page permissions
1732          *
1733          * @param $action String the action to check
1734          * @param $user User user to check
1735          * @param $errors Array list of current errors
1736          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1737          * @param $short Boolean short circuit on first error
1738          *
1739          * @return Array list of errors
1740          */
1741         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1742                 # Protect css/js subpages of user pages
1743                 # XXX: this might be better using restrictions
1744                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1745                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1746                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1747                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1748                                 $errors[] = array( 'customcssprotected' );
1749                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1750                                 $errors[] = array( 'customjsprotected' );
1751                         }
1752                 }
1753
1754                 return $errors;
1755         }
1756
1757         /**
1758          * Check against page_restrictions table requirements on this
1759          * page. The user must possess all required rights for this
1760          * action.
1761          *
1762          * @param $action String the action to check
1763          * @param $user User user to check
1764          * @param $errors Array list of current errors
1765          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1766          * @param $short Boolean short circuit on first error
1767          *
1768          * @return Array list of errors
1769          */
1770         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1771                 foreach ( $this->getRestrictions( $action ) as $right ) {
1772                         // Backwards compatibility, rewrite sysop -> protect
1773                         if ( $right == 'sysop' ) {
1774                                 $right = 'protect';
1775                         }
1776                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1777                                 // Users with 'editprotected' permission can edit protected pages
1778                                 // without cascading option turned on.
1779                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1780                                         || $this->mCascadeRestriction )
1781                                 {
1782                                         $errors[] = array( 'protectedpagetext', $right );
1783                                 }
1784                         }
1785                 }
1786
1787                 return $errors;
1788         }
1789
1790         /**
1791          * Check restrictions on cascading pages.
1792          *
1793          * @param $action String the action to check
1794          * @param $user User to check
1795          * @param $errors Array list of current errors
1796          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1797          * @param $short Boolean short circuit on first error
1798          *
1799          * @return Array list of errors
1800          */
1801         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1802                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1803                         # We /could/ use the protection level on the source page, but it's
1804                         # fairly ugly as we have to establish a precedence hierarchy for pages
1805                         # included by multiple cascade-protected pages. So just restrict
1806                         # it to people with 'protect' permission, as they could remove the
1807                         # protection anyway.
1808                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1809                         # Cascading protection depends on more than this page...
1810                         # Several cascading protected pages may include this page...
1811                         # Check each cascading level
1812                         # This is only for protection restrictions, not for all actions
1813                         if ( isset( $restrictions[$action] ) ) {
1814                                 foreach ( $restrictions[$action] as $right ) {
1815                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1816                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1817                                                 $pages = '';
1818                                                 foreach ( $cascadingSources as $page )
1819                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1820                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1821                                         }
1822                                 }
1823                         }
1824                 }
1825
1826                 return $errors;
1827         }
1828
1829         /**
1830          * Check action permissions not already checked in checkQuickPermissions
1831          *
1832          * @param $action String the action to check
1833          * @param $user User to check
1834          * @param $errors Array list of current errors
1835          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1836          * @param $short Boolean short circuit on first error
1837          *
1838          * @return Array list of errors
1839          */
1840         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1841                 if ( $action == 'protect' ) {
1842                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1843                                 // If they can't edit, they shouldn't protect.
1844                                 $errors[] = array( 'protect-cantedit' );
1845                         }
1846                 } elseif ( $action == 'create' ) {
1847                         $title_protection = $this->getTitleProtection();
1848                         if( $title_protection ) {
1849                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1850                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1851                                 }
1852                                 if( $title_protection['pt_create_perm'] == '' ||
1853                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1854                                 {
1855                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1856                                 }
1857                         }
1858                 } elseif ( $action == 'move' ) {
1859                         // Check for immobile pages
1860                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1861                                 // Specific message for this case
1862                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1863                         } elseif ( !$this->isMovable() ) {
1864                                 // Less specific message for rarer cases
1865                                 $errors[] = array( 'immobile-source-page' );
1866                         }
1867                 } elseif ( $action == 'move-target' ) {
1868                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1869                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1870                         } elseif ( !$this->isMovable() ) {
1871                                 $errors[] = array( 'immobile-target-page' );
1872                         }
1873                 }
1874                 return $errors;
1875         }
1876
1877         /**
1878          * Check that the user isn't blocked from editting.
1879          *
1880          * @param $action String the action to check
1881          * @param $user User to check
1882          * @param $errors Array list of current errors
1883          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1884          * @param $short Boolean short circuit on first error
1885          *
1886          * @return Array list of errors
1887          */
1888         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1889                 // Account creation blocks handled at userlogin.
1890                 // Unblocking handled in SpecialUnblock
1891                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1892                         return $errors;
1893                 }
1894
1895                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1896
1897                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1898                         $errors[] = array( 'confirmedittext' );
1899                 }
1900
1901                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1902                         // Don't block the user from editing their own talk page unless they've been
1903                         // explicitly blocked from that too.
1904                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1905                         $block = $user->mBlock;
1906
1907                         // This is from OutputPage::blockedPage
1908                         // Copied at r23888 by werdna
1909
1910                         $id = $user->blockedBy();
1911                         $reason = $user->blockedFor();
1912                         if ( $reason == '' ) {
1913                                 $reason = wfMsg( 'blockednoreason' );
1914                         }
1915                         $ip = $user->getRequest()->getIP();
1916
1917                         if ( is_numeric( $id ) ) {
1918                                 $name = User::whoIs( $id );
1919                         } else {
1920                                 $name = $id;
1921                         }
1922
1923                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1924                         $blockid = $block->getId();
1925                         $blockExpiry = $user->mBlock->mExpiry;
1926                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1927                         if ( $blockExpiry == 'infinity' ) {
1928                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1929                         } else {
1930                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1931                         }
1932
1933                         $intended = strval( $user->mBlock->getTarget() );
1934
1935                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1936                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1937                 }
1938
1939                 return $errors;
1940         }
1941
1942         /**
1943          * Check that the user is allowed to read this page.
1944          *
1945          * @param $action String the action to check
1946          * @param $user User to check
1947          * @param $errors Array list of current errors
1948          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1949          * @param $short Boolean short circuit on first error
1950          *
1951          * @return Array list of errors
1952          */
1953         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1954                 static $useShortcut = null;
1955
1956                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1957                 if ( is_null( $useShortcut ) ) {
1958                         global $wgGroupPermissions, $wgRevokePermissions;
1959                         $useShortcut = true;
1960                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1961                                 # Not a public wiki, so no shortcut
1962                                 $useShortcut = false;
1963                         } elseif ( !empty( $wgRevokePermissions ) ) {
1964                                 /**
1965                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1966                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1967                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1968                                  * reading is allowed.
1969                                  */
1970                                 foreach ( $wgRevokePermissions as $perms ) {
1971                                         if ( !empty( $perms['read'] ) ) {
1972                                                 # We might be removing the read right from the user, so no shortcut
1973                                                 $useShortcut = false;
1974                                                 break;
1975                                         }
1976                                 }
1977                         }
1978                 }
1979
1980                 # Shortcut for public wikis, allows skipping quite a bit of code
1981                 if ( $useShortcut ) {
1982                         return $errors;
1983                 }
1984
1985                 # If the user is allowed to read pages, he is allowed to read all pages
1986                 if ( $user->isAllowed( 'read' ) ) {
1987                         return $errors;
1988                 }
1989
1990                 # Always grant access to the login page.
1991                 # Even anons need to be able to log in.
1992                 if ( $this->isSpecial( 'Userlogin' )
1993                         || $this->isSpecial( 'ChangePassword' )
1994                         || $this->isSpecial( 'PasswordReset' )
1995                 ) {
1996                         return $errors;
1997                 }
1998
1999                 # Time to check the whitelist
2000                 global $wgWhitelistRead;
2001
2002                 # Only to these checks is there's something to check against
2003                 if ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2004                         # Check for explicit whitelisting
2005                         $name = $this->getPrefixedText();
2006                         $dbName = $this->getPrefixedDBKey();
2007
2008                         // Check with and without underscores
2009                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2010                                 return $errors;
2011                         }
2012
2013                         # Old settings might have the title prefixed with
2014                         # a colon for main-namespace pages
2015                         if ( $this->getNamespace() == NS_MAIN ) {
2016                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2017                                         return $errors;
2018                                 }
2019                         }
2020
2021                         # If it's a special page, ditch the subpage bit and check again
2022                         if ( $this->isSpecialPage() ) {
2023                                 $name = $this->getDBkey();
2024                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2025                                 if ( $name !== false ) {
2026                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2027                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2028                                                 return $errors;
2029                                         }
2030                                 }
2031                         }
2032                 }
2033
2034                 $errors[] = $this->missingPermissionError( $action, $short );
2035                 return $errors;
2036         }
2037
2038         /**
2039          * Get a description array when the user doesn't have the right to perform
2040          * $action (i.e. when User::isAllowed() returns false)
2041          *
2042          * @param $action String the action to check
2043          * @param $short Boolean short circuit on first error
2044          * @return Array list of errors
2045          */
2046         private function missingPermissionError( $action, $short ) {
2047                 // We avoid expensive display logic for quickUserCan's and such
2048                 if ( $short ) {
2049                         return array( 'badaccess-group0' );
2050                 }
2051
2052                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2053                         User::getGroupsWithPermission( $action ) );
2054
2055                 if ( count( $groups ) ) {
2056                         global $wgLang;
2057                         return array(
2058                                 'badaccess-groups',
2059                                 $wgLang->commaList( $groups ),
2060                                 count( $groups )
2061                         );
2062                 } else {
2063                         return array( 'badaccess-group0' );
2064                 }
2065         }
2066
2067         /**
2068          * Can $user perform $action on this page? This is an internal function,
2069          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2070          * checks on wfReadOnly() and blocks)
2071          *
2072          * @param $action String action that permission needs to be checked for
2073          * @param $user User to check
2074          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2075          * @param $short Bool Set this to true to stop after the first permission error.
2076          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2077          */
2078         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2079                 wfProfileIn( __METHOD__ );
2080
2081                 # Read has special handling
2082                 if ( $action == 'read' ) {
2083                         $checks = array(
2084                                 'checkPermissionHooks',
2085                                 'checkReadPermissions',
2086                         );
2087                 } else {
2088                         $checks = array(
2089                                 'checkQuickPermissions',
2090                                 'checkPermissionHooks',
2091                                 'checkSpecialsAndNSPermissions',
2092                                 'checkCSSandJSPermissions',
2093                                 'checkPageRestrictions',
2094                                 'checkCascadingSourcesRestrictions',
2095                                 'checkActionPermissions',
2096                                 'checkUserBlock'
2097                         );
2098                 }
2099
2100                 $errors = array();
2101                 while( count( $checks ) > 0 &&
2102                                 !( $short && count( $errors ) > 0 ) ) {
2103                         $method = array_shift( $checks );
2104                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2105                 }
2106
2107                 wfProfileOut( __METHOD__ );
2108                 return $errors;
2109         }
2110
2111         /**
2112          * Protect css subpages of user pages: can $wgUser edit
2113          * this page?
2114          *
2115          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2116          * @return Bool
2117          */
2118         public function userCanEditCssSubpage() {
2119                 global $wgUser;
2120                 wfDeprecated( __METHOD__ );
2121                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2122                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2123         }
2124
2125         /**
2126          * Protect js subpages of user pages: can $wgUser edit
2127          * this page?
2128          *
2129          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2130          * @return Bool
2131          */
2132         public function userCanEditJsSubpage() {
2133                 global $wgUser;
2134                 wfDeprecated( __METHOD__ );
2135                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2136                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2137         }
2138
2139         /**
2140          * Get a filtered list of all restriction types supported by this wiki.
2141          * @param bool $exists True to get all restriction types that apply to
2142          * titles that do exist, False for all restriction types that apply to
2143          * titles that do not exist
2144          * @return array
2145          */
2146         public static function getFilteredRestrictionTypes( $exists = true ) {
2147                 global $wgRestrictionTypes;
2148                 $types = $wgRestrictionTypes;
2149                 if ( $exists ) {
2150                         # Remove the create restriction for existing titles
2151                         $types = array_diff( $types, array( 'create' ) );
2152                 } else {
2153                         # Only the create and upload restrictions apply to non-existing titles
2154                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2155                 }
2156                 return $types;
2157         }
2158
2159         /**
2160          * Returns restriction types for the current Title
2161          *
2162          * @return array applicable restriction types
2163          */
2164         public function getRestrictionTypes() {
2165                 if ( $this->isSpecialPage() ) {
2166                         return array();
2167                 }
2168
2169                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2170
2171                 if ( $this->getNamespace() != NS_FILE ) {
2172                         # Remove the upload restriction for non-file titles
2173                         $types = array_diff( $types, array( 'upload' ) );
2174                 }
2175
2176                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2177
2178                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2179                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2180
2181                 return $types;
2182         }
2183
2184         /**
2185          * Is this title subject to title protection?
2186          * Title protection is the one applied against creation of such title.
2187          *
2188          * @return Mixed An associative array representing any existent title
2189          *   protection, or false if there's none.
2190          */
2191         private function getTitleProtection() {
2192                 // Can't protect pages in special namespaces
2193                 if ( $this->getNamespace() < 0 ) {
2194                         return false;
2195                 }
2196
2197                 // Can't protect pages that exist.
2198                 if ( $this->exists() ) {
2199                         return false;
2200                 }
2201
2202                 if ( !isset( $this->mTitleProtection ) ) {
2203                         $dbr = wfGetDB( DB_SLAVE );
2204                         $res = $dbr->select( 'protected_titles', '*',
2205                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2206                                 __METHOD__ );
2207
2208                         // fetchRow returns false if there are no rows.
2209                         $this->mTitleProtection = $dbr->fetchRow( $res );
2210                 }
2211                 return $this->mTitleProtection;
2212         }
2213
2214         /**
2215          * Update the title protection status
2216          *
2217          * @param $create_perm String Permission required for creation
2218          * @param $reason String Reason for protection
2219          * @param $expiry String Expiry timestamp
2220          * @return boolean true
2221          */
2222         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2223                 global $wgUser, $wgContLang;
2224
2225                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
2226                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
2227                         // No change
2228                         return true;
2229                 }
2230
2231                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
2232
2233                 $dbw = wfGetDB( DB_MASTER );
2234
2235                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
2236
2237                 $expiry_description = '';
2238                 if ( $encodedExpiry != $dbw->getInfinity() ) {
2239                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
2240                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
2241                 } else {
2242                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
2243                 }
2244
2245                 # Update protection table
2246                 if ( $create_perm != '' ) {
2247                         $this->mTitleProtection = array(
2248                                         'pt_namespace' => $namespace,
2249                                         'pt_title' => $title,
2250                                         'pt_create_perm' => $create_perm,
2251                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
2252                                         'pt_expiry' => $encodedExpiry,
2253                                         'pt_user' => $wgUser->getId(),
2254                                         'pt_reason' => $reason,
2255                                 );
2256                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
2257                                 $this->mTitleProtection, __METHOD__     );
2258                 } else {
2259                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
2260                                 'pt_title' => $title ), __METHOD__ );
2261                         $this->mTitleProtection = false;
2262                 }
2263
2264                 # Update the protection log
2265                 if ( $dbw->affectedRows() ) {
2266                         $log = new LogPage( 'protect' );
2267
2268                         if ( $create_perm ) {
2269                                 $params = array( "[create=$create_perm] $expiry_description", '' );
2270                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
2271                         } else {
2272                                 $log->addEntry( 'unprotect', $this, $reason );
2273                         }
2274                 }
2275
2276                 return true;
2277         }
2278
2279         /**
2280          * Remove any title protection due to page existing
2281          */
2282         public function deleteTitleProtection() {
2283                 $dbw = wfGetDB( DB_MASTER );
2284
2285                 $dbw->delete(
2286                         'protected_titles',
2287                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2288                         __METHOD__
2289                 );
2290                 $this->mTitleProtection = false;
2291         }
2292
2293         /**
2294          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2295          *
2296          * @param $action String Action to check (default: edit)
2297          * @return Bool
2298          */
2299         public function isSemiProtected( $action = 'edit' ) {
2300                 if ( $this->exists() ) {
2301                         $restrictions = $this->getRestrictions( $action );
2302                         if ( count( $restrictions ) > 0 ) {
2303                                 foreach ( $restrictions as $restriction ) {
2304                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2305                                                 return false;
2306                                         }
2307                                 }
2308                         } else {
2309                                 # Not protected
2310                                 return false;
2311                         }
2312                         return true;
2313                 } else {
2314                         # If it doesn't exist, it can't be protected
2315                         return false;
2316                 }
2317         }
2318
2319         /**
2320          * Does the title correspond to a protected article?
2321          *
2322          * @param $action String the action the page is protected from,
2323          * by default checks all actions.
2324          * @return Bool
2325          */
2326         public function isProtected( $action = '' ) {
2327                 global $wgRestrictionLevels;
2328
2329                 $restrictionTypes = $this->getRestrictionTypes();
2330
2331                 # Special pages have inherent protection
2332                 if( $this->isSpecialPage() ) {
2333                         return true;
2334                 }
2335
2336                 # Check regular protection levels
2337                 foreach ( $restrictionTypes as $type ) {
2338                         if ( $action == $type || $action == '' ) {
2339                                 $r = $this->getRestrictions( $type );
2340                                 foreach ( $wgRestrictionLevels as $level ) {
2341                                         if ( in_array( $level, $r ) && $level != '' ) {
2342                                                 return true;
2343                                         }
2344                                 }
2345                         }
2346                 }
2347
2348                 return false;
2349         }
2350
2351         /**
2352          * Determines if $user is unable to edit this page because it has been protected
2353          * by $wgNamespaceProtection.
2354          *
2355          * @param $user User object to check permissions
2356          * @return Bool
2357          */
2358         public function isNamespaceProtected( User $user ) {
2359                 global $wgNamespaceProtection;
2360
2361                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2362                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2363                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2364                                         return true;
2365                                 }
2366                         }
2367                 }
2368                 return false;
2369         }
2370
2371         /**
2372          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2373          *
2374          * @return Bool If the page is subject to cascading restrictions.
2375          */
2376         public function isCascadeProtected() {
2377                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2378                 return ( $sources > 0 );
2379         }
2380
2381         /**
2382          * Cascading protection: Get the source of any cascading restrictions on this page.
2383          *
2384          * @param $getPages Bool Whether or not to retrieve the actual pages
2385          *        that the restrictions have come from.
2386          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2387          *     have come, false for none, or true if such restrictions exist, but $getPages
2388          *     was not set.  The restriction array is an array of each type, each of which
2389          *     contains a array of unique groups.
2390          */
2391         public function getCascadeProtectionSources( $getPages = true ) {
2392                 global $wgContLang;
2393                 $pagerestrictions = array();
2394
2395                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2396                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2397                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2398                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2399                 }
2400
2401                 wfProfileIn( __METHOD__ );
2402
2403                 $dbr = wfGetDB( DB_SLAVE );
2404
2405                 if ( $this->getNamespace() == NS_FILE ) {
2406                         $tables = array( 'imagelinks', 'page_restrictions' );
2407                         $where_clauses = array(
2408                                 'il_to' => $this->getDBkey(),
2409                                 'il_from=pr_page',
2410                                 'pr_cascade' => 1
2411                         );
2412                 } else {
2413                         $tables = array( 'templatelinks', 'page_restrictions' );
2414                         $where_clauses = array(
2415                                 'tl_namespace' => $this->getNamespace(),
2416                                 'tl_title' => $this->getDBkey(),
2417                                 'tl_from=pr_page',
2418                                 'pr_cascade' => 1
2419                         );
2420                 }
2421
2422                 if ( $getPages ) {
2423                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2424                                                    'pr_expiry', 'pr_type', 'pr_level' );
2425                         $where_clauses[] = 'page_id=pr_page';
2426                         $tables[] = 'page';
2427                 } else {
2428                         $cols = array( 'pr_expiry' );
2429                 }
2430
2431                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2432
2433                 $sources = $getPages ? array() : false;
2434                 $now = wfTimestampNow();
2435                 $purgeExpired = false;
2436
2437                 foreach ( $res as $row ) {
2438                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2439                         if ( $expiry > $now ) {
2440                                 if ( $getPages ) {
2441                                         $page_id = $row->pr_page;
2442                                         $page_ns = $row->page_namespace;
2443                                         $page_title = $row->page_title;
2444                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2445                                         # Add groups needed for each restriction type if its not already there
2446                                         # Make sure this restriction type still exists
2447
2448                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2449                                                 $pagerestrictions[$row->pr_type] = array();
2450                                         }
2451
2452                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2453                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2454                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2455                                         }
2456                                 } else {
2457                                         $sources = true;
2458                                 }
2459                         } else {
2460                                 // Trigger lazy purge of expired restrictions from the db
2461                                 $purgeExpired = true;
2462                         }
2463                 }
2464                 if ( $purgeExpired ) {
2465                         Title::purgeExpiredRestrictions();
2466                 }
2467
2468                 if ( $getPages ) {
2469                         $this->mCascadeSources = $sources;
2470                         $this->mCascadingRestrictions = $pagerestrictions;
2471                 } else {
2472                         $this->mHasCascadingRestrictions = $sources;
2473                 }
2474
2475                 wfProfileOut( __METHOD__ );
2476                 return array( $sources, $pagerestrictions );
2477         }
2478
2479         /**
2480          * Accessor/initialisation for mRestrictions
2481          *
2482          * @param $action String action that permission needs to be checked for
2483          * @return Array of Strings the array of groups allowed to edit this article
2484          */
2485         public function getRestrictions( $action ) {
2486                 if ( !$this->mRestrictionsLoaded ) {
2487                         $this->loadRestrictions();
2488                 }
2489                 return isset( $this->mRestrictions[$action] )
2490                                 ? $this->mRestrictions[$action]
2491                                 : array();
2492         }
2493
2494         /**
2495          * Get the expiry time for the restriction against a given action
2496          *
2497          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2498          *      or not protected at all, or false if the action is not recognised.
2499          */
2500         public function getRestrictionExpiry( $action ) {
2501                 if ( !$this->mRestrictionsLoaded ) {
2502                         $this->loadRestrictions();
2503                 }
2504                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2505         }
2506
2507         /**
2508          * Returns cascading restrictions for the current article
2509          *
2510          * @return Boolean
2511          */
2512         function areRestrictionsCascading() {
2513                 if ( !$this->mRestrictionsLoaded ) {
2514                         $this->loadRestrictions();
2515                 }
2516
2517                 return $this->mCascadeRestriction;
2518         }
2519
2520         /**
2521          * Loads a string into mRestrictions array
2522          *
2523          * @param $res Resource restrictions as an SQL result.
2524          * @param $oldFashionedRestrictions String comma-separated list of page
2525          *        restrictions from page table (pre 1.10)
2526          */
2527         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2528                 $rows = array();
2529
2530                 foreach ( $res as $row ) {
2531                         $rows[] = $row;
2532                 }
2533
2534                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2535         }
2536
2537         /**
2538          * Compiles list of active page restrictions from both page table (pre 1.10)
2539          * and page_restrictions table for this existing page.
2540          * Public for usage by LiquidThreads.
2541          *
2542          * @param $rows array of db result objects
2543          * @param $oldFashionedRestrictions string comma-separated list of page
2544          *        restrictions from page table (pre 1.10)
2545          */
2546         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2547                 global $wgContLang;
2548                 $dbr = wfGetDB( DB_SLAVE );
2549
2550                 $restrictionTypes = $this->getRestrictionTypes();
2551
2552                 foreach ( $restrictionTypes as $type ) {
2553                         $this->mRestrictions[$type] = array();
2554                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2555                 }
2556
2557                 $this->mCascadeRestriction = false;
2558
2559                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2560
2561                 if ( $oldFashionedRestrictions === null ) {
2562                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2563                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2564                 }
2565
2566                 if ( $oldFashionedRestrictions != '' ) {
2567
2568                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2569                                 $temp = explode( '=', trim( $restrict ) );
2570                                 if ( count( $temp ) == 1 ) {
2571                                         // old old format should be treated as edit/move restriction
2572                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2573                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2574                                 } else {
2575                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2576                                 }
2577                         }
2578
2579                         $this->mOldRestrictions = true;
2580
2581                 }
2582
2583                 if ( count( $rows ) ) {
2584                         # Current system - load second to make them override.
2585                         $now = wfTimestampNow();
2586                         $purgeExpired = false;
2587
2588                         # Cycle through all the restrictions.
2589                         foreach ( $rows as $row ) {
2590
2591                                 // Don't take care of restrictions types that aren't allowed
2592                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2593                                         continue;
2594
2595                                 // This code should be refactored, now that it's being used more generally,
2596                                 // But I don't really see any harm in leaving it in Block for now -werdna
2597                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2598
2599                                 // Only apply the restrictions if they haven't expired!
2600                                 if ( !$expiry || $expiry > $now ) {
2601                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2602                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2603
2604                                         $this->mCascadeRestriction |= $row->pr_cascade;
2605                                 } else {
2606                                         // Trigger a lazy purge of expired restrictions
2607                                         $purgeExpired = true;
2608                                 }
2609                         }
2610
2611                         if ( $purgeExpired ) {
2612                                 Title::purgeExpiredRestrictions();
2613                         }
2614                 }
2615
2616                 $this->mRestrictionsLoaded = true;
2617         }
2618
2619         /**
2620          * Load restrictions from the page_restrictions table
2621          *
2622          * @param $oldFashionedRestrictions String comma-separated list of page
2623          *        restrictions from page table (pre 1.10)
2624          */
2625         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2626                 global $wgContLang;
2627                 if ( !$this->mRestrictionsLoaded ) {
2628                         if ( $this->exists() ) {
2629                                 $dbr = wfGetDB( DB_SLAVE );
2630
2631                                 $res = $dbr->select(
2632                                         'page_restrictions',
2633                                         '*',
2634                                         array( 'pr_page' => $this->getArticleId() ),
2635                                         __METHOD__
2636                                 );
2637
2638                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2639                         } else {
2640                                 $title_protection = $this->getTitleProtection();
2641
2642                                 if ( $title_protection ) {
2643                                         $now = wfTimestampNow();
2644                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2645
2646                                         if ( !$expiry || $expiry > $now ) {
2647                                                 // Apply the restrictions
2648                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2649                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2650                                         } else { // Get rid of the old restrictions
2651                                                 Title::purgeExpiredRestrictions();
2652                                                 $this->mTitleProtection = false;
2653                                         }
2654                                 } else {
2655                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2656                                 }
2657                                 $this->mRestrictionsLoaded = true;
2658                         }
2659                 }
2660         }
2661
2662         /**
2663          * Purge expired restrictions from the page_restrictions table
2664          */
2665         static function purgeExpiredRestrictions() {
2666                 $dbw = wfGetDB( DB_MASTER );
2667                 $dbw->delete(
2668                         'page_restrictions',
2669                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2670                         __METHOD__
2671                 );
2672
2673                 $dbw->delete(
2674                         'protected_titles',
2675                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2676                         __METHOD__
2677                 );
2678         }
2679
2680         /**
2681          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2682          *
2683          * @return Bool
2684          */
2685         public function hasSubpages() {
2686                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2687                         # Duh
2688                         return false;
2689                 }
2690
2691                 # We dynamically add a member variable for the purpose of this method
2692                 # alone to cache the result.  There's no point in having it hanging
2693                 # around uninitialized in every Title object; therefore we only add it
2694                 # if needed and don't declare it statically.
2695                 if ( isset( $this->mHasSubpages ) ) {
2696                         return $this->mHasSubpages;
2697                 }
2698
2699                 $subpages = $this->getSubpages( 1 );
2700                 if ( $subpages instanceof TitleArray ) {
2701                         return $this->mHasSubpages = (bool)$subpages->count();
2702                 }
2703                 return $this->mHasSubpages = false;
2704         }
2705
2706         /**
2707          * Get all subpages of this page.
2708          *
2709          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2710          * @return mixed TitleArray, or empty array if this page's namespace
2711          *  doesn't allow subpages
2712          */
2713         public function getSubpages( $limit = -1 ) {
2714                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2715                         return array();
2716                 }
2717
2718                 $dbr = wfGetDB( DB_SLAVE );
2719                 $conds['page_namespace'] = $this->getNamespace();
2720                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2721                 $options = array();
2722                 if ( $limit > -1 ) {
2723                         $options['LIMIT'] = $limit;
2724                 }
2725                 return $this->mSubpages = TitleArray::newFromResult(
2726                         $dbr->select( 'page',
2727                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2728                                 $conds,
2729                                 __METHOD__,
2730                                 $options
2731                         )
2732                 );
2733         }
2734
2735         /**
2736          * Is there a version of this page in the deletion archive?
2737          *
2738          * @return Int the number of archived revisions
2739          */
2740         public function isDeleted() {
2741                 if ( $this->getNamespace() < 0 ) {
2742                         $n = 0;
2743                 } else {
2744                         $dbr = wfGetDB( DB_SLAVE );
2745
2746                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2747                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2748                                 __METHOD__
2749                         );
2750                         if ( $this->getNamespace() == NS_FILE ) {
2751                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2752                                         array( 'fa_name' => $this->getDBkey() ),
2753                                         __METHOD__
2754                                 );
2755                         }
2756                 }
2757                 return (int)$n;
2758         }
2759
2760         /**
2761          * Is there a version of this page in the deletion archive?
2762          *
2763          * @return Boolean
2764          */
2765         public function isDeletedQuick() {
2766                 if ( $this->getNamespace() < 0 ) {
2767                         return false;
2768                 }
2769                 $dbr = wfGetDB( DB_SLAVE );
2770                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2771                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2772                         __METHOD__
2773                 );
2774                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2775                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2776                                 array( 'fa_name' => $this->getDBkey() ),
2777                                 __METHOD__
2778                         );
2779                 }
2780                 return $deleted;
2781         }
2782
2783         /**
2784          * Get the number of views of this page
2785          *
2786          * @return int The view count for the page
2787          */
2788         public function getCount() {
2789                 if ( $this->mCounter == -1 ) {
2790                         if ( $this->exists() ) {
2791                                 $dbr = wfGetDB( DB_SLAVE );
2792                                 $this->mCounter = $dbr->selectField( 'page',
2793                                         'page_counter',
2794                                         array( 'page_id' => $this->getArticleID() ),
2795                                         __METHOD__
2796                                 );
2797                         } else {
2798                                 $this->mCounter = 0;
2799                         }
2800                 }
2801
2802                 return $this->mCounter;
2803         }
2804
2805         /**
2806          * Get the article ID for this Title from the link cache,
2807          * adding it if necessary
2808          *
2809          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2810          *  for update
2811          * @return Int the ID
2812          */
2813         public function getArticleID( $flags = 0 ) {
2814                 if ( $this->getNamespace() < 0 ) {
2815                         return $this->mArticleID = 0;
2816                 }
2817                 $linkCache = LinkCache::singleton();
2818                 if ( $flags & self::GAID_FOR_UPDATE ) {
2819                         $oldUpdate = $linkCache->forUpdate( true );
2820                         $linkCache->clearLink( $this );
2821                         $this->mArticleID = $linkCache->addLinkObj( $this );
2822                         $linkCache->forUpdate( $oldUpdate );
2823                 } else {
2824                         if ( -1 == $this->mArticleID ) {
2825                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2826                         }
2827                 }
2828                 return $this->mArticleID;
2829         }
2830
2831         /**
2832          * Is this an article that is a redirect page?
2833          * Uses link cache, adding it if necessary
2834          *
2835          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2836          * @return Bool
2837          */
2838         public function isRedirect( $flags = 0 ) {
2839                 if ( !is_null( $this->mRedirect ) ) {
2840                         return $this->mRedirect;
2841                 }
2842                 # Calling getArticleID() loads the field from cache as needed
2843                 if ( !$this->getArticleID( $flags ) ) {
2844                         return $this->mRedirect = false;
2845                 }
2846                 $linkCache = LinkCache::singleton();
2847                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2848
2849                 return $this->mRedirect;
2850         }
2851
2852         /**
2853          * What is the length of this page?
2854          * Uses link cache, adding it if necessary
2855          *
2856          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2857          * @return Int
2858          */
2859         public function getLength( $flags = 0 ) {
2860                 if ( $this->mLength != -1 ) {
2861                         return $this->mLength;
2862                 }
2863                 # Calling getArticleID() loads the field from cache as needed
2864                 if ( !$this->getArticleID( $flags ) ) {
2865                         return $this->mLength = 0;
2866                 }
2867                 $linkCache = LinkCache::singleton();
2868                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2869
2870                 return $this->mLength;
2871         }
2872
2873         /**
2874          * What is the page_latest field for this page?
2875          *
2876          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2877          * @return Int or 0 if the page doesn't exist
2878          */
2879         public function getLatestRevID( $flags = 0 ) {
2880                 if ( $this->mLatestID !== false ) {
2881                         return intval( $this->mLatestID );
2882                 }
2883                 # Calling getArticleID() loads the field from cache as needed
2884                 if ( !$this->getArticleID( $flags ) ) {
2885                         return $this->mLatestID = 0;
2886                 }
2887                 $linkCache = LinkCache::singleton();
2888                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2889
2890                 return $this->mLatestID;
2891         }
2892
2893         /**
2894          * This clears some fields in this object, and clears any associated
2895          * keys in the "bad links" section of the link cache.
2896          *
2897          * - This is called from Article::doEdit() and Article::insertOn() to allow
2898          * loading of the new page_id. It's also called from
2899          * Article::doDeleteArticle()
2900          *
2901          * @param $newid Int the new Article ID
2902          */
2903         public function resetArticleID( $newid ) {
2904                 $linkCache = LinkCache::singleton();
2905                 $linkCache->clearLink( $this );
2906
2907                 if ( $newid === false ) {
2908                         $this->mArticleID = -1;
2909                 } else {
2910                         $this->mArticleID = intval( $newid );
2911                 }
2912                 $this->mRestrictionsLoaded = false;
2913                 $this->mRestrictions = array();
2914                 $this->mRedirect = null;
2915                 $this->mLength = -1;
2916                 $this->mLatestID = false;
2917                 $this->mCounter = -1;
2918         }
2919
2920         /**
2921          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2922          *
2923          * @param $text String containing title to capitalize
2924          * @param $ns int namespace index, defaults to NS_MAIN
2925          * @return String containing capitalized title
2926          */
2927         public static function capitalize( $text, $ns = NS_MAIN ) {
2928                 global $wgContLang;
2929
2930                 if ( MWNamespace::isCapitalized( $ns ) ) {
2931                         return $wgContLang->ucfirst( $text );
2932                 } else {
2933                         return $text;
2934                 }
2935         }
2936
2937         /**
2938          * Secure and split - main initialisation function for this object
2939          *
2940          * Assumes that mDbkeyform has been set, and is urldecoded
2941          * and uses underscores, but not otherwise munged.  This function
2942          * removes illegal characters, splits off the interwiki and
2943          * namespace prefixes, sets the other forms, and canonicalizes
2944          * everything.
2945          *
2946          * @return Bool true on success
2947          */
2948         private function secureAndSplit() {
2949                 global $wgContLang, $wgLocalInterwiki;
2950
2951                 # Initialisation
2952                 $this->mInterwiki = $this->mFragment = '';
2953                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2954
2955                 $dbkey = $this->mDbkeyform;
2956
2957                 # Strip Unicode bidi override characters.
2958                 # Sometimes they slip into cut-n-pasted page titles, where the
2959                 # override chars get included in list displays.
2960                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2961
2962                 # Clean up whitespace
2963                 # Note: use of the /u option on preg_replace here will cause
2964                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2965                 # conveniently disabling them.
2966                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2967                 $dbkey = trim( $dbkey, '_' );
2968
2969                 if ( $dbkey == '' ) {
2970                         return false;
2971                 }
2972
2973                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2974                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2975                         return false;
2976                 }
2977
2978                 $this->mDbkeyform = $dbkey;
2979
2980                 # Initial colon indicates main namespace rather than specified default
2981                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2982                 if ( ':' == $dbkey[0] ) {
2983                         $this->mNamespace = NS_MAIN;
2984                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2985                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2986                 }
2987
2988                 # Namespace or interwiki prefix
2989                 $firstPass = true;
2990                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2991                 do {
2992                         $m = array();
2993                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2994                                 $p = $m[1];
2995                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2996                                         # Ordinary namespace
2997                                         $dbkey = $m[2];
2998                                         $this->mNamespace = $ns;
2999                                         # For Talk:X pages, check if X has a "namespace" prefix
3000                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3001                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3002                                                         # Disallow Talk:File:x type titles...
3003                                                         return false;
3004                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3005                                                         # Disallow Talk:Interwiki:x type titles...
3006                                                         return false;
3007                                                 }
3008                                         }
3009                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3010                                         if ( !$firstPass ) {
3011                                                 # Can't make a local interwiki link to an interwiki link.
3012                                                 # That's just crazy!
3013                                                 return false;
3014                                         }
3015
3016                                         # Interwiki link
3017                                         $dbkey = $m[2];
3018                                         $this->mInterwiki = $wgContLang->lc( $p );
3019
3020                                         # Redundant interwiki prefix to the local wiki
3021                                         if ( $wgLocalInterwiki !== false
3022                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3023                                         {
3024                                                 if ( $dbkey == '' ) {
3025                                                         # Can't have an empty self-link
3026                                                         return false;
3027                                                 }
3028                                                 $this->mInterwiki = '';
3029                                                 $firstPass = false;
3030                                                 # Do another namespace split...
3031                                                 continue;
3032                                         }
3033
3034                                         # If there's an initial colon after the interwiki, that also
3035                                         # resets the default namespace
3036                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3037                                                 $this->mNamespace = NS_MAIN;
3038                                                 $dbkey = substr( $dbkey, 1 );
3039                                         }
3040                                 }
3041                                 # If there's no recognized interwiki or namespace,
3042                                 # then let the colon expression be part of the title.
3043                         }
3044                         break;
3045                 } while ( true );
3046
3047                 # We already know that some pages won't be in the database!
3048                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3049                         $this->mArticleID = 0;
3050                 }
3051                 $fragment = strstr( $dbkey, '#' );
3052                 if ( false !== $fragment ) {
3053                         $this->setFragment( $fragment );
3054                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3055                         # remove whitespace again: prevents "Foo_bar_#"
3056                         # becoming "Foo_bar_"
3057                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3058                 }
3059
3060                 # Reject illegal characters.
3061                 $rxTc = self::getTitleInvalidRegex();
3062                 if ( preg_match( $rxTc, $dbkey ) ) {
3063                         return false;
3064                 }
3065
3066                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3067                 # reachable due to the way web browsers deal with 'relative' URLs.
3068                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3069                 if ( strpos( $dbkey, '.' ) !== false &&
3070                          ( $dbkey === '.' || $dbkey === '..' ||
3071                            strpos( $dbkey, './' ) === 0  ||
3072                            strpos( $dbkey, '../' ) === 0 ||
3073                            strpos( $dbkey, '/./' ) !== false ||
3074                            strpos( $dbkey, '/../' ) !== false  ||
3075                            substr( $dbkey, -2 ) == '/.' ||
3076                            substr( $dbkey, -3 ) == '/..' ) )
3077                 {
3078                         return false;
3079                 }
3080
3081                 # Magic tilde sequences? Nu-uh!
3082                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3083                         return false;
3084                 }
3085
3086                 # Limit the size of titles to 255 bytes. This is typically the size of the
3087                 # underlying database field. We make an exception for special pages, which
3088                 # don't need to be stored in the database, and may edge over 255 bytes due
3089                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3090                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3091                   strlen( $dbkey ) > 512 )
3092                 {
3093                         return false;
3094                 }
3095
3096                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3097                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3098                 # other site might be case-sensitive.
3099                 $this->mUserCaseDBKey = $dbkey;
3100                 if ( $this->mInterwiki == '' ) {
3101                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3102                 }
3103
3104                 # Can't make a link to a namespace alone... "empty" local links can only be
3105                 # self-links with a fragment identifier.
3106                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3107                         return false;
3108                 }
3109
3110                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3111                 // IP names are not allowed for accounts, and can only be referring to
3112                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3113                 // there are numerous ways to present the same IP. Having sp:contribs scan
3114                 // them all is silly and having some show the edits and others not is
3115                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3116                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3117                         ? IP::sanitizeIP( $dbkey )
3118                         : $dbkey;
3119
3120                 // Any remaining initial :s are illegal.
3121                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3122                         return false;
3123                 }
3124
3125                 # Fill fields
3126                 $this->mDbkeyform = $dbkey;
3127                 $this->mUrlform = wfUrlencode( $dbkey );
3128
3129                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3130
3131                 return true;
3132         }
3133
3134         /**
3135          * Get an array of Title objects linking to this Title
3136          * Also stores the IDs in the link cache.
3137          *
3138          * WARNING: do not use this function on arbitrary user-supplied titles!
3139          * On heavily-used templates it will max out the memory.
3140          *
3141          * @param $options Array: may be FOR UPDATE
3142          * @param $table String: table name
3143          * @param $prefix String: fields prefix
3144          * @return Array of Title objects linking here
3145          */
3146         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3147                 $linkCache = LinkCache::singleton();
3148
3149                 if ( count( $options ) > 0 ) {
3150                         $db = wfGetDB( DB_MASTER );
3151                 } else {
3152                         $db = wfGetDB( DB_SLAVE );
3153                 }
3154
3155                 $res = $db->select(
3156                         array( 'page', $table ),
3157                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3158                         array(
3159                                 "{$prefix}_from=page_id",
3160                                 "{$prefix}_namespace" => $this->getNamespace(),
3161                                 "{$prefix}_title"     => $this->getDBkey() ),
3162                         __METHOD__,
3163                         $options
3164                 );
3165
3166                 $retVal = array();
3167                 if ( $db->numRows( $res ) ) {
3168                         foreach ( $res as $row ) {
3169                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3170                                 if ( $titleObj ) {
3171                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3172                                         $retVal[] = $titleObj;
3173                                 }
3174                         }
3175                 }
3176                 return $retVal;
3177         }
3178
3179         /**
3180          * Get an array of Title objects using this Title as a template
3181          * Also stores the IDs in the link cache.
3182          *
3183          * WARNING: do not use this function on arbitrary user-supplied titles!
3184          * On heavily-used templates it will max out the memory.
3185          *
3186          * @param $options Array: may be FOR UPDATE
3187          * @return Array of Title the Title objects linking here
3188          */
3189         public function getTemplateLinksTo( $options = array() ) {
3190                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3191         }
3192
3193         /**
3194          * Get an array of Title objects referring to non-existent articles linked from this page
3195          *
3196          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3197          * @return Array of Title the Title objects
3198          */
3199         public function getBrokenLinksFrom() {
3200                 if ( $this->getArticleId() == 0 ) {
3201                         # All links from article ID 0 are false positives
3202                         return array();
3203                 }
3204
3205                 $dbr = wfGetDB( DB_SLAVE );
3206                 $res = $dbr->select(
3207                         array( 'page', 'pagelinks' ),
3208                         array( 'pl_namespace', 'pl_title' ),
3209                         array(
3210                                 'pl_from' => $this->getArticleId(),
3211                                 'page_namespace IS NULL'
3212                         ),
3213                         __METHOD__, array(),
3214                         array(
3215                                 'page' => array(
3216                                         'LEFT JOIN',
3217                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3218                                 )
3219                         )
3220                 );
3221
3222                 $retVal = array();
3223                 foreach ( $res as $row ) {
3224                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3225                 }
3226                 return $retVal;
3227         }
3228
3229
3230         /**
3231          * Get a list of URLs to purge from the Squid cache when this
3232          * page changes
3233          *
3234          * @return Array of String the URLs
3235          */
3236         public function getSquidURLs() {
3237                 global $wgContLang;
3238
3239                 $urls = array(
3240                         $this->getInternalURL(),
3241                         $this->getInternalURL( 'action=history' )
3242                 );
3243
3244                 // purge variant urls as well
3245                 if ( $wgContLang->hasVariants() ) {
3246                         $variants = $wgContLang->getVariants();
3247                         foreach ( $variants as $vCode ) {
3248                                 $urls[] = $this->getInternalURL( '', $vCode );
3249                         }
3250                 }
3251
3252                 return $urls;
3253         }
3254
3255         /**
3256          * Purge all applicable Squid URLs
3257          */
3258         public function purgeSquid() {
3259                 global $wgUseSquid;
3260                 if ( $wgUseSquid ) {
3261                         $urls = $this->getSquidURLs();
3262                         $u = new SquidUpdate( $urls );
3263                         $u->doUpdate();
3264                 }
3265         }
3266
3267         /**
3268          * Move this page without authentication
3269          *
3270          * @param $nt Title the new page Title
3271          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3272          */
3273         public function moveNoAuth( &$nt ) {
3274                 return $this->moveTo( $nt, false );
3275         }
3276
3277         /**
3278          * Check whether a given move operation would be valid.
3279          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3280          *
3281          * @param $nt Title the new title
3282          * @param $auth Bool indicates whether $wgUser's permissions
3283          *  should be checked
3284          * @param $reason String is the log summary of the move, used for spam checking
3285          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3286          */
3287         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3288                 global $wgUser;
3289
3290                 $errors = array();
3291                 if ( !$nt ) {
3292                         // Normally we'd add this to $errors, but we'll get
3293                         // lots of syntax errors if $nt is not an object
3294                         return array( array( 'badtitletext' ) );
3295                 }
3296                 if ( $this->equals( $nt ) ) {
3297                         $errors[] = array( 'selfmove' );
3298                 }
3299                 if ( !$this->isMovable() ) {
3300                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3301                 }
3302                 if ( $nt->getInterwiki() != '' ) {
3303                         $errors[] = array( 'immobile-target-namespace-iw' );
3304                 }
3305                 if ( !$nt->isMovable() ) {
3306                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3307                 }
3308
3309                 $oldid = $this->getArticleID();
3310                 $newid = $nt->getArticleID();
3311
3312                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3313                         $errors[] = array( 'articleexists' );
3314                 }
3315                 if ( ( $this->getDBkey() == '' ) ||
3316                          ( !$oldid ) ||
3317                          ( $nt->getDBkey() == '' ) ) {
3318                         $errors[] = array( 'badarticleerror' );
3319                 }
3320
3321                 // Image-specific checks
3322                 if ( $this->getNamespace() == NS_FILE ) {
3323                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3324                 }
3325
3326                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3327                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3328                 }
3329
3330                 if ( $auth ) {
3331                         $errors = wfMergeErrorArrays( $errors,
3332                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3333                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3334                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3335                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3336                 }
3337
3338                 $match = EditPage::matchSummarySpamRegex( $reason );
3339                 if ( $match !== false ) {
3340                         // This is kind of lame, won't display nice
3341                         $errors[] = array( 'spamprotectiontext' );
3342                 }
3343
3344                 $err = null;
3345                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3346                         $errors[] = array( 'hookaborted', $err );
3347                 }
3348
3349                 # The move is allowed only if (1) the target doesn't exist, or
3350                 # (2) the target is a redirect to the source, and has no history
3351                 # (so we can undo bad moves right after they're done).
3352
3353                 if ( 0 != $newid ) { # Target exists; check for validity
3354                         if ( !$this->isValidMoveTarget( $nt ) ) {
3355                                 $errors[] = array( 'articleexists' );
3356                         }
3357                 } else {
3358                         $tp = $nt->getTitleProtection();
3359                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3360                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3361                                 $errors[] = array( 'cantmove-titleprotected' );
3362                         }
3363                 }
3364                 if ( empty( $errors ) ) {
3365                         return true;
3366                 }
3367                 return $errors;
3368         }
3369
3370         /**
3371          * Check if the requested move target is a valid file move target
3372          * @param Title $nt Target title
3373          * @return array List of errors
3374          */
3375         protected function validateFileMoveOperation( $nt ) {
3376                 global $wgUser;
3377
3378                 $errors = array();
3379
3380                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3381
3382                 $file = wfLocalFile( $this );
3383                 if ( $file->exists() ) {
3384                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3385                                 $errors[] = array( 'imageinvalidfilename' );
3386                         }
3387                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3388                                 $errors[] = array( 'imagetypemismatch' );
3389                         }
3390                 }
3391
3392                 if ( $nt->getNamespace() != NS_FILE ) {
3393                         $errors[] = array( 'imagenocrossnamespace' );
3394                         // From here we want to do checks on a file object, so if we can't
3395                         // create one, we must return.
3396                         return $errors;
3397                 }
3398
3399                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3400
3401                 $destFile = wfLocalFile( $nt );
3402                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3403                         $errors[] = array( 'file-exists-sharedrepo' );
3404                 }
3405
3406                 return $errors;
3407         }
3408
3409         /**
3410          * Move a title to a new location
3411          *
3412          * @param $nt Title the new title
3413          * @param $auth Bool indicates whether $wgUser's permissions
3414          *  should be checked
3415          * @param $reason String the reason for the move
3416          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3417          *  Ignored if the user doesn't have the suppressredirect right.
3418          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3419          */
3420         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3421                 global $wgUser;
3422                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3423                 if ( is_array( $err ) ) {
3424                         // Auto-block user's IP if the account was "hard" blocked
3425                         $wgUser->spreadAnyEditBlock();
3426                         return $err;
3427                 }
3428
3429                 // If it is a file, move it first.
3430                 // It is done before all other moving stuff is done because it's hard to revert.
3431                 $dbw = wfGetDB( DB_MASTER );
3432                 if ( $this->getNamespace() == NS_FILE ) {
3433                         $file = wfLocalFile( $this );
3434                         if ( $file->exists() ) {
3435                                 $status = $file->move( $nt );
3436                                 if ( !$status->isOk() ) {
3437                                         return $status->getErrorsArray();
3438                                 }
3439                         }
3440                 }
3441                 // Clear RepoGroup process cache
3442                 RepoGroup::singleton()->clearCache( $this );
3443                 RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3444
3445                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3446                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3447                 $protected = $this->isProtected();
3448                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3449
3450                 // Do the actual move
3451                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3452                 if ( is_array( $err ) ) {
3453                         # @todo FIXME: What about the File we have already moved?
3454                         $dbw->rollback();
3455                         return $err;
3456                 }
3457
3458                 $redirid = $this->getArticleID();
3459
3460                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3461                 // cl_timestamp, which may disturb time-based lists on some sites.
3462                 $prefixes = $dbw->select(
3463                         'categorylinks',
3464                         array( 'cl_sortkey_prefix', 'cl_to' ),
3465                         array( 'cl_from' => $pageid ),
3466                         __METHOD__
3467                 );
3468                 foreach ( $prefixes as $prefixRow ) {
3469                         $prefix = $prefixRow->cl_sortkey_prefix;
3470                         $catTo = $prefixRow->cl_to;
3471                         $dbw->update( 'categorylinks',
3472                                 array(
3473                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3474                                                 $nt->getCategorySortkey( $prefix ) ),
3475                                         'cl_timestamp=cl_timestamp' ),
3476                                 array(
3477                                         'cl_from' => $pageid,
3478                                         'cl_to' => $catTo ),
3479                                 __METHOD__
3480                         );
3481                 }
3482
3483                 if ( $protected ) {
3484                         # Protect the redirect title as the title used to be...
3485                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3486                                 array(
3487                                         'pr_page'    => $redirid,
3488                                         'pr_type'    => 'pr_type',
3489                                         'pr_level'   => 'pr_level',
3490                                         'pr_cascade' => 'pr_cascade',
3491                                         'pr_user'    => 'pr_user',
3492                                         'pr_expiry'  => 'pr_expiry'
3493                                 ),
3494                                 array( 'pr_page' => $pageid ),
3495                                 __METHOD__,
3496                                 array( 'IGNORE' )
3497                         );
3498                         # Update the protection log
3499                         $log = new LogPage( 'protect' );
3500                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3501                         if ( $reason ) {
3502                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3503                         }
3504                         // @todo FIXME: $params?
3505                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3506                 }
3507
3508                 # Update watchlists
3509                 $oldnamespace = $this->getNamespace() & ~1;
3510                 $newnamespace = $nt->getNamespace() & ~1;
3511                 $oldtitle = $this->getDBkey();
3512                 $newtitle = $nt->getDBkey();
3513
3514                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3515                         WatchedItem::duplicateEntries( $this, $nt );
3516                 }
3517
3518                 # Update search engine
3519                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3520                 $u->doUpdate();
3521                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3522                 $u->doUpdate();
3523
3524                 $dbw->commit();
3525
3526                 # Update site_stats
3527                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3528                         # No longer a content page
3529                         # Not viewed, edited, removing
3530                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3531                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3532                         # Now a content page
3533                         # Not viewed, edited, adding
3534                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3535                 } elseif ( $pageCountChange ) {
3536                         # Redirect added
3537                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3538                 } else {
3539                         # Nothing special
3540                         $u = false;
3541                 }
3542                 if ( $u ) {
3543                         $u->doUpdate();
3544                 }
3545
3546                 # Update message cache for interface messages
3547                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3548                         # @bug 17860: old article can be deleted, if this the case,
3549                         # delete it from message cache
3550                         if ( $this->getArticleID() === 0 ) {
3551                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3552                         } else {
3553                                 $rev = Revision::newFromTitle( $this );
3554                                 MessageCache::singleton()->replace( $this->getDBkey(), $rev->getText() );
3555                         }
3556                 }
3557                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3558                         $rev = Revision::newFromTitle( $nt );
3559                         MessageCache::singleton()->replace( $nt->getDBkey(), $rev->getText() );
3560                 }
3561
3562                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3563                 return true;
3564         }
3565
3566         /**
3567          * Move page to a title which is either a redirect to the
3568          * source page or nonexistent
3569          *
3570          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3571          * @param $reason String The reason for the move
3572          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3573          *   if the user doesn't have the suppressredirect right
3574          */
3575         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3576                 global $wgUser, $wgContLang;
3577
3578                 if ( $nt->exists() ) {
3579                         $moveOverRedirect = true;
3580                         $logType = 'move_redir';
3581                 } else {
3582                         $moveOverRedirect = false;
3583                         $logType = 'move';
3584                 }
3585
3586                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3587
3588                 $logEntry = new ManualLogEntry( 'move', $logType );
3589                 $logEntry->setPerformer( $wgUser );
3590                 $logEntry->setTarget( $this );
3591                 $logEntry->setComment( $reason );
3592                 $logEntry->setParameters( array(
3593                         '4::target' => $nt->getPrefixedText(),
3594                         '5::noredir' => $redirectSuppressed ? '1': '0',
3595                 ) );
3596
3597                 $formatter = LogFormatter::newFromEntry( $logEntry );
3598                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3599                 $comment = $formatter->getPlainActionText();
3600                 if ( $reason ) {
3601                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3602                 }
3603                 # Truncate for whole multibyte characters.
3604                 $comment = $wgContLang->truncate( $comment, 255 );
3605
3606                 $oldid = $this->getArticleID();
3607                 $latest = $this->getLatestRevID();
3608
3609                 $dbw = wfGetDB( DB_MASTER );
3610
3611                 if ( $moveOverRedirect ) {
3612                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3613
3614                         $newid = $nt->getArticleID();
3615                         $newns = $nt->getNamespace();
3616                         $newdbk = $nt->getDBkey();
3617
3618                         # Delete the old redirect. We don't save it to history since
3619                         # by definition if we've got here it's rather uninteresting.
3620                         # We have to remove it so that the next step doesn't trigger
3621                         # a conflict on the unique namespace+title index...
3622                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3623                         if ( !$dbw->cascadingDeletes() ) {
3624                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3625
3626                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3627                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3628                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3629                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3630                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3631                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3632                                 $dbw->delete( 'iwlinks', array( 'iwl_from' => $newid ), __METHOD__ );
3633                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3634                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3635                         }
3636                         // If the target page was recently created, it may have an entry in recentchanges still
3637                         $dbw->delete( 'recentchanges',
3638                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3639                                 __METHOD__
3640                         );
3641                 }
3642
3643                 # Save a null revision in the page's history notifying of the move
3644                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3645                 if ( !is_object( $nullRevision ) ) {
3646                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3647                 }
3648                 $nullRevId = $nullRevision->insertOn( $dbw );
3649
3650                 $now = wfTimestampNow();
3651                 # Change the name of the target page:
3652                 $dbw->update( 'page',
3653                         /* SET */ array(
3654                                 'page_touched'   => $dbw->timestamp( $now ),
3655                                 'page_namespace' => $nt->getNamespace(),
3656                                 'page_title'     => $nt->getDBkey(),
3657                                 'page_latest'    => $nullRevId,
3658                         ),
3659                         /* WHERE */ array( 'page_id' => $oldid ),
3660                         __METHOD__
3661                 );
3662                 $nt->resetArticleID( $oldid );
3663
3664                 $article = WikiPage::factory( $nt );
3665                 wfRunHooks( 'NewRevisionFromEditComplete',
3666                         array( $article, $nullRevision, $latest, $wgUser ) );
3667                 $article->setCachedLastEditTime( $now );
3668
3669                 # Recreate the redirect, this time in the other direction.
3670                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3671                         $mwRedir = MagicWord::get( 'redirect' );
3672                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3673                         $redirectArticle = WikiPage::factory( $this );
3674                         $newid = $redirectArticle->insertOn( $dbw );
3675                         if ( $newid ) { // sanity
3676                                 $redirectRevision = new Revision( array(
3677                                         'page'    => $newid,
3678                                         'comment' => $comment,
3679                                         'text'    => $redirectText ) );
3680                                 $redirectRevision->insertOn( $dbw );
3681                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3682
3683                                 wfRunHooks( 'NewRevisionFromEditComplete',
3684                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3685
3686                                 # Now, we record the link from the redirect to the new title.
3687                                 # It should have no other outgoing links...
3688                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3689                                 $dbw->insert( 'pagelinks',
3690                                         array(
3691                                                 'pl_from'      => $newid,
3692                                                 'pl_namespace' => $nt->getNamespace(),
3693                                                 'pl_title'     => $nt->getDBkey() ),
3694                                         __METHOD__ );
3695                         }
3696                 } else {
3697                         $this->resetArticleID( 0 );
3698                 }
3699
3700                 # Log the move
3701                 $logid = $logEntry->insert();
3702                 $logEntry->publish( $logid );
3703
3704                 # Purge caches for old and new titles
3705                 if ( $moveOverRedirect ) {
3706                         # A simple purge is enough when moving over a redirect
3707                         $nt->purgeSquid();
3708                 } else {
3709                         # Purge caches as per article creation, including any pages that link to this title
3710                         Article::onArticleCreate( $nt );
3711                 }
3712                 $this->purgeSquid();
3713         }
3714
3715         /**
3716          * Move this page's subpages to be subpages of $nt
3717          *
3718          * @param $nt Title Move target
3719          * @param $auth bool Whether $wgUser's permissions should be checked
3720          * @param $reason string The reason for the move
3721          * @param $createRedirect bool Whether to create redirects from the old subpages to
3722          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3723          * @return mixed array with old page titles as keys, and strings (new page titles) or
3724          *     arrays (errors) as values, or an error array with numeric indices if no pages
3725          *     were moved
3726          */
3727         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3728                 global $wgMaximumMovedPages;
3729                 // Check permissions
3730                 if ( !$this->userCan( 'move-subpages' ) ) {
3731                         return array( 'cant-move-subpages' );
3732                 }
3733                 // Do the source and target namespaces support subpages?
3734                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3735                         return array( 'namespace-nosubpages',
3736                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3737                 }
3738                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3739                         return array( 'namespace-nosubpages',
3740                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3741                 }
3742
3743                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3744                 $retval = array();
3745                 $count = 0;
3746                 foreach ( $subpages as $oldSubpage ) {
3747                         $count++;
3748                         if ( $count > $wgMaximumMovedPages ) {
3749                                 $retval[$oldSubpage->getPrefixedTitle()] =
3750                                                 array( 'movepage-max-pages',
3751                                                         $wgMaximumMovedPages );
3752                                 break;
3753                         }
3754
3755                         // We don't know whether this function was called before
3756                         // or after moving the root page, so check both
3757                         // $this and $nt
3758                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3759                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3760                         {
3761                                 // When moving a page to a subpage of itself,
3762                                 // don't move it twice
3763                                 continue;
3764                         }
3765                         $newPageName = preg_replace(
3766                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3767                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3768                                         $oldSubpage->getDBkey() );
3769                         if ( $oldSubpage->isTalkPage() ) {
3770                                 $newNs = $nt->getTalkPage()->getNamespace();
3771                         } else {
3772                                 $newNs = $nt->getSubjectPage()->getNamespace();
3773                         }
3774                         # Bug 14385: we need makeTitleSafe because the new page names may
3775                         # be longer than 255 characters.
3776                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3777
3778                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3779                         if ( $success === true ) {
3780                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3781                         } else {
3782                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3783                         }
3784                 }
3785                 return $retval;
3786         }
3787
3788         /**
3789          * Checks if this page is just a one-rev redirect.
3790          * Adds lock, so don't use just for light purposes.
3791          *
3792          * @return Bool
3793          */
3794         public function isSingleRevRedirect() {
3795                 $dbw = wfGetDB( DB_MASTER );
3796                 # Is it a redirect?
3797                 $row = $dbw->selectRow( 'page',
3798                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3799                         $this->pageCond(),
3800                         __METHOD__,
3801                         array( 'FOR UPDATE' )
3802                 );
3803                 # Cache some fields we may want
3804                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3805                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3806                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3807                 if ( !$this->mRedirect ) {
3808                         return false;
3809                 }
3810                 # Does the article have a history?
3811                 $row = $dbw->selectField( array( 'page', 'revision' ),
3812                         'rev_id',
3813                         array( 'page_namespace' => $this->getNamespace(),
3814                                 'page_title' => $this->getDBkey(),
3815                                 'page_id=rev_page',
3816                                 'page_latest != rev_id'
3817                         ),
3818                         __METHOD__,
3819                         array( 'FOR UPDATE' )
3820                 );
3821                 # Return true if there was no history
3822                 return ( $row === false );
3823         }
3824
3825         /**
3826          * Checks if $this can be moved to a given Title
3827          * - Selects for update, so don't call it unless you mean business
3828          *
3829          * @param $nt Title the new title to check
3830          * @return Bool
3831          */
3832         public function isValidMoveTarget( $nt ) {
3833                 # Is it an existing file?
3834                 if ( $nt->getNamespace() == NS_FILE ) {
3835                         $file = wfLocalFile( $nt );
3836                         if ( $file->exists() ) {
3837                                 wfDebug( __METHOD__ . ": file exists\n" );
3838                                 return false;
3839                         }
3840                 }
3841                 # Is it a redirect with no history?
3842                 if ( !$nt->isSingleRevRedirect() ) {
3843                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3844                         return false;
3845                 }
3846                 # Get the article text
3847                 $rev = Revision::newFromTitle( $nt );
3848                 if( !is_object( $rev ) ){
3849                         return false;
3850                 }
3851                 $text = $rev->getText();
3852                 # Does the redirect point to the source?
3853                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3854                 $m = array();
3855                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3856                         $redirTitle = Title::newFromText( $m[1] );
3857                         if ( !is_object( $redirTitle ) ||
3858                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3859                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3860                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3861                                 return false;
3862                         }
3863                 } else {
3864                         # Fail safe
3865                         wfDebug( __METHOD__ . ": failsafe\n" );
3866                         return false;
3867                 }
3868                 return true;
3869         }
3870
3871         /**
3872          * Get categories to which this Title belongs and return an array of
3873          * categories' names.
3874          *
3875          * @return Array of parents in the form:
3876          *        $parent => $currentarticle
3877          */
3878         public function getParentCategories() {
3879                 global $wgContLang;
3880
3881                 $data = array();
3882
3883                 $titleKey = $this->getArticleId();
3884
3885                 if ( $titleKey === 0 ) {
3886                         return $data;
3887                 }
3888
3889                 $dbr = wfGetDB( DB_SLAVE );
3890
3891                 $res = $dbr->select( 'categorylinks', '*',
3892                         array(
3893                                 'cl_from' => $titleKey,
3894                         ),
3895                         __METHOD__,
3896                         array()
3897                 );
3898
3899                 if ( $dbr->numRows( $res ) > 0 ) {
3900                         foreach ( $res as $row ) {
3901                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3902                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3903                         }
3904                 }
3905                 return $data;
3906         }
3907
3908         /**
3909          * Get a tree of parent categories
3910          *
3911          * @param $children Array with the children in the keys, to check for circular refs
3912          * @return Array Tree of parent categories
3913          */
3914         public function getParentCategoryTree( $children = array() ) {
3915                 $stack = array();
3916                 $parents = $this->getParentCategories();
3917
3918                 if ( $parents ) {
3919                         foreach ( $parents as $parent => $current ) {
3920                                 if ( array_key_exists( $parent, $children ) ) {
3921                                         # Circular reference
3922                                         $stack[$parent] = array();
3923                                 } else {
3924                                         $nt = Title::newFromText( $parent );
3925                                         if ( $nt ) {
3926                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3927                                         }
3928                                 }
3929                         }
3930                 }
3931
3932                 return $stack;
3933         }
3934
3935         /**
3936          * Get an associative array for selecting this title from
3937          * the "page" table
3938          *
3939          * @return Array suitable for the $where parameter of DB::select()
3940          */
3941         public function pageCond() {
3942                 if ( $this->mArticleID > 0 ) {
3943                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3944                         return array( 'page_id' => $this->mArticleID );
3945                 } else {
3946                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3947                 }
3948         }
3949
3950         /**
3951          * Get the revision ID of the previous revision
3952          *
3953          * @param $revId Int Revision ID. Get the revision that was before this one.
3954          * @param $flags Int Title::GAID_FOR_UPDATE
3955          * @return Int|Bool Old revision ID, or FALSE if none exists
3956          */
3957         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3958                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3959                 return $db->selectField( 'revision', 'rev_id',
3960                         array(
3961                                 'rev_page' => $this->getArticleId( $flags ),
3962                                 'rev_id < ' . intval( $revId )
3963                         ),
3964                         __METHOD__,
3965                         array( 'ORDER BY' => 'rev_id DESC' )
3966                 );
3967         }
3968
3969         /**
3970          * Get the revision ID of the next revision
3971          *
3972          * @param $revId Int Revision ID. Get the revision that was after this one.
3973          * @param $flags Int Title::GAID_FOR_UPDATE
3974          * @return Int|Bool Next revision ID, or FALSE if none exists
3975          */
3976         public function getNextRevisionID( $revId, $flags = 0 ) {
3977                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3978                 return $db->selectField( 'revision', 'rev_id',
3979                         array(
3980                                 'rev_page' => $this->getArticleId( $flags ),
3981                                 'rev_id > ' . intval( $revId )
3982                         ),
3983                         __METHOD__,
3984                         array( 'ORDER BY' => 'rev_id' )
3985                 );
3986         }
3987
3988         /**
3989          * Get the first revision of the page
3990          *
3991          * @param $flags Int Title::GAID_FOR_UPDATE
3992          * @return Revision|Null if page doesn't exist
3993          */
3994         public function getFirstRevision( $flags = 0 ) {
3995                 $pageId = $this->getArticleId( $flags );
3996                 if ( $pageId ) {
3997                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3998                         $row = $db->selectRow( 'revision', '*',
3999                                 array( 'rev_page' => $pageId ),
4000                                 __METHOD__,
4001                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4002                         );
4003                         if ( $row ) {
4004                                 return new Revision( $row );
4005                         }
4006                 }
4007                 return null;
4008         }
4009
4010         /**
4011          * Get the oldest revision timestamp of this page
4012          *
4013          * @param $flags Int Title::GAID_FOR_UPDATE
4014          * @return String: MW timestamp
4015          */
4016         public function getEarliestRevTime( $flags = 0 ) {
4017                 $rev = $this->getFirstRevision( $flags );
4018                 return $rev ? $rev->getTimestamp() : null;
4019         }
4020
4021         /**
4022          * Check if this is a new page
4023          *
4024          * @return bool
4025          */
4026         public function isNewPage() {
4027                 $dbr = wfGetDB( DB_SLAVE );
4028                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4029         }
4030
4031         /**
4032          * Get the number of revisions between the given revision.
4033          * Used for diffs and other things that really need it.
4034          *
4035          * @param $old int|Revision Old revision or rev ID (first before range)
4036          * @param $new int|Revision New revision or rev ID (first after range)
4037          * @return Int Number of revisions between these revisions.
4038          */
4039         public function countRevisionsBetween( $old, $new ) {
4040                 if ( !( $old instanceof Revision ) ) {
4041                         $old = Revision::newFromTitle( $this, (int)$old );
4042                 }
4043                 if ( !( $new instanceof Revision ) ) {
4044                         $new = Revision::newFromTitle( $this, (int)$new );
4045                 }
4046                 if ( !$old || !$new ) {
4047                         return 0; // nothing to compare
4048                 }
4049                 $dbr = wfGetDB( DB_SLAVE );
4050                 return (int)$dbr->selectField( 'revision', 'count(*)',
4051                         array(
4052                                 'rev_page' => $this->getArticleId(),
4053                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4054                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4055                         ),
4056                         __METHOD__
4057                 );
4058         }
4059
4060         /**
4061          * Get the number of authors between the given revision IDs.
4062          * Used for diffs and other things that really need it.
4063          *
4064          * @param $old int|Revision Old revision or rev ID (first before range)
4065          * @param $new int|Revision New revision or rev ID (first after range)
4066          * @param $limit Int Maximum number of authors
4067          * @return Int Number of revision authors between these revisions.
4068          */
4069         public function countAuthorsBetween( $old, $new, $limit ) {
4070                 if ( !( $old instanceof Revision ) ) {
4071                         $old = Revision::newFromTitle( $this, (int)$old );
4072                 }
4073                 if ( !( $new instanceof Revision ) ) {
4074                         $new = Revision::newFromTitle( $this, (int)$new );
4075                 }
4076                 if ( !$old || !$new ) {
4077                         return 0; // nothing to compare
4078                 }
4079                 $dbr = wfGetDB( DB_SLAVE );
4080                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4081                         array(
4082                                 'rev_page' => $this->getArticleID(),
4083                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4084                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4085                         ), __METHOD__,
4086                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4087                 );
4088                 return (int)$dbr->numRows( $res );
4089         }
4090
4091         /**
4092          * Compare with another title.
4093          *
4094          * @param $title Title
4095          * @return Bool
4096          */
4097         public function equals( Title $title ) {
4098                 // Note: === is necessary for proper matching of number-like titles.
4099                 return $this->getInterwiki() === $title->getInterwiki()
4100                         && $this->getNamespace() == $title->getNamespace()
4101                         && $this->getDBkey() === $title->getDBkey();
4102         }
4103
4104         /**
4105          * Check if this title is a subpage of another title
4106          *
4107          * @param $title Title
4108          * @return Bool
4109          */
4110         public function isSubpageOf( Title $title ) {
4111                 return $this->getInterwiki() === $title->getInterwiki()
4112                         && $this->getNamespace() == $title->getNamespace()
4113                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4114         }
4115
4116         /**
4117          * Check if page exists.  For historical reasons, this function simply
4118          * checks for the existence of the title in the page table, and will
4119          * thus return false for interwiki links, special pages and the like.
4120          * If you want to know if a title can be meaningfully viewed, you should
4121          * probably call the isKnown() method instead.
4122          *
4123          * @return Bool
4124          */
4125         public function exists() {
4126                 return $this->getArticleId() != 0;
4127         }
4128
4129         /**
4130          * Should links to this title be shown as potentially viewable (i.e. as
4131          * "bluelinks"), even if there's no record by this title in the page
4132          * table?
4133          *
4134          * This function is semi-deprecated for public use, as well as somewhat
4135          * misleadingly named.  You probably just want to call isKnown(), which
4136          * calls this function internally.
4137          *
4138          * (ISSUE: Most of these checks are cheap, but the file existence check
4139          * can potentially be quite expensive.  Including it here fixes a lot of
4140          * existing code, but we might want to add an optional parameter to skip
4141          * it and any other expensive checks.)
4142          *
4143          * @return Bool
4144          */
4145         public function isAlwaysKnown() {
4146                 if ( $this->mInterwiki != '' ) {
4147                         return true;  // any interwiki link might be viewable, for all we know
4148                 }
4149                 switch( $this->mNamespace ) {
4150                         case NS_MEDIA:
4151                         case NS_FILE:
4152                                 // file exists, possibly in a foreign repo
4153                                 return (bool)wfFindFile( $this );
4154                         case NS_SPECIAL:
4155                                 // valid special page
4156                                 return SpecialPageFactory::exists( $this->getDBkey() );
4157                         case NS_MAIN:
4158                                 // selflink, possibly with fragment
4159                                 return $this->mDbkeyform == '';
4160                         case NS_MEDIAWIKI:
4161                                 // known system message
4162                                 return $this->hasSourceText() !== false;
4163                         default:
4164                                 return false;
4165                 }
4166         }
4167
4168         /**
4169          * Does this title refer to a page that can (or might) be meaningfully
4170          * viewed?  In particular, this function may be used to determine if
4171          * links to the title should be rendered as "bluelinks" (as opposed to
4172          * "redlinks" to non-existent pages).
4173          *
4174          * @return Bool
4175          */
4176         public function isKnown() {
4177                 return $this->isAlwaysKnown() || $this->exists();
4178         }
4179
4180         /**
4181          * Does this page have source text?
4182          *
4183          * @return Boolean
4184          */
4185         public function hasSourceText() {
4186                 if ( $this->exists() ) {
4187                         return true;
4188                 }
4189
4190                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4191                         // If the page doesn't exist but is a known system message, default
4192                         // message content will be displayed, same for language subpages-
4193                         // Use always content language to avoid loading hundreds of languages
4194                         // to get the link color.
4195                         global $wgContLang;
4196                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4197                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4198                         return $message->exists();
4199                 }
4200
4201                 return false;
4202         }
4203
4204         /**
4205          * Get the default message text or false if the message doesn't exist
4206          *
4207          * @return String or false
4208          */
4209         public function getDefaultMessageText() {
4210                 global $wgContLang;
4211
4212                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4213                         return false;
4214                 }
4215
4216                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4217                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4218
4219                 if ( $message->exists() ) {
4220                         return $message->plain();
4221                 } else {
4222                         return false;
4223                 }
4224         }
4225
4226         /**
4227          * Updates page_touched for this page; called from LinksUpdate.php
4228          *
4229          * @return Bool true if the update succeded
4230          */
4231         public function invalidateCache() {
4232                 if ( wfReadOnly() ) {
4233                         return false;
4234                 }
4235                 $dbw = wfGetDB( DB_MASTER );
4236                 $success = $dbw->update(
4237                         'page',
4238                         array( 'page_touched' => $dbw->timestamp() ),
4239                         $this->pageCond(),
4240                         __METHOD__
4241                 );
4242                 HTMLFileCache::clearFileCache( $this );
4243                 return $success;
4244         }
4245
4246         /**
4247          * Update page_touched timestamps and send squid purge messages for
4248          * pages linking to this title. May be sent to the job queue depending
4249          * on the number of links. Typically called on create and delete.
4250          */
4251         public function touchLinks() {
4252                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4253                 $u->doUpdate();
4254
4255                 if ( $this->getNamespace() == NS_CATEGORY ) {
4256                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4257                         $u->doUpdate();
4258                 }
4259         }
4260
4261         /**
4262          * Get the last touched timestamp
4263          *
4264          * @param $db DatabaseBase: optional db
4265          * @return String last-touched timestamp
4266          */
4267         public function getTouched( $db = null ) {
4268                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4269                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4270                 return $touched;
4271         }
4272
4273         /**
4274          * Get the timestamp when this page was updated since the user last saw it.
4275          *
4276          * @param $user User
4277          * @return String|Null
4278          */
4279         public function getNotificationTimestamp( $user = null ) {
4280                 global $wgUser, $wgShowUpdatedMarker;
4281                 // Assume current user if none given
4282                 if ( !$user ) {
4283                         $user = $wgUser;
4284                 }
4285                 // Check cache first
4286                 $uid = $user->getId();
4287                 // avoid isset here, as it'll return false for null entries
4288                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4289                         return $this->mNotificationTimestamp[$uid];
4290                 }
4291                 if ( !$uid || !$wgShowUpdatedMarker ) {
4292                         return $this->mNotificationTimestamp[$uid] = false;
4293                 }
4294                 // Don't cache too much!
4295                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4296                         $this->mNotificationTimestamp = array();
4297                 }
4298                 $dbr = wfGetDB( DB_SLAVE );
4299                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4300                         'wl_notificationtimestamp',
4301                         array( 'wl_namespace' => $this->getNamespace(),
4302                                 'wl_title' => $this->getDBkey(),
4303                                 'wl_user' => $user->getId()
4304                         ),
4305                         __METHOD__
4306                 );
4307                 return $this->mNotificationTimestamp[$uid];
4308         }
4309
4310         /**
4311          * Generate strings used for xml 'id' names in monobook tabs
4312          *
4313          * @param $prepend string defaults to 'nstab-'
4314          * @return String XML 'id' name
4315          */
4316         public function getNamespaceKey( $prepend = 'nstab-' ) {
4317                 global $wgContLang;
4318                 // Gets the subject namespace if this title
4319                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4320                 // Checks if cononical namespace name exists for namespace
4321                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4322                         // Uses canonical namespace name
4323                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4324                 } else {
4325                         // Uses text of namespace
4326                         $namespaceKey = $this->getSubjectNsText();
4327                 }
4328                 // Makes namespace key lowercase
4329                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4330                 // Uses main
4331                 if ( $namespaceKey == '' ) {
4332                         $namespaceKey = 'main';
4333                 }
4334                 // Changes file to image for backwards compatibility
4335                 if ( $namespaceKey == 'file' ) {
4336                         $namespaceKey = 'image';
4337                 }
4338                 return $prepend . $namespaceKey;
4339         }
4340
4341         /**
4342          * Get all extant redirects to this Title
4343          *
4344          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4345          * @return Array of Title redirects to this title
4346          */
4347         public function getRedirectsHere( $ns = null ) {
4348                 $redirs = array();
4349
4350                 $dbr = wfGetDB( DB_SLAVE );
4351                 $where = array(
4352                         'rd_namespace' => $this->getNamespace(),
4353                         'rd_title' => $this->getDBkey(),
4354                         'rd_from = page_id'
4355                 );
4356                 if ( !is_null( $ns ) ) {
4357                         $where['page_namespace'] = $ns;
4358                 }
4359
4360                 $res = $dbr->select(
4361                         array( 'redirect', 'page' ),
4362                         array( 'page_namespace', 'page_title' ),
4363                         $where,
4364                         __METHOD__
4365                 );
4366
4367                 foreach ( $res as $row ) {
4368                         $redirs[] = self::newFromRow( $row );
4369                 }
4370                 return $redirs;
4371         }
4372
4373         /**
4374          * Check if this Title is a valid redirect target
4375          *
4376          * @return Bool
4377          */
4378         public function isValidRedirectTarget() {
4379                 global $wgInvalidRedirectTargets;
4380
4381                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4382                 if ( $this->isSpecial( 'Userlogout' ) ) {
4383                         return false;
4384                 }
4385
4386                 foreach ( $wgInvalidRedirectTargets as $target ) {
4387                         if ( $this->isSpecial( $target ) ) {
4388                                 return false;
4389                         }
4390                 }
4391
4392                 return true;
4393         }
4394
4395         /**
4396          * Get a backlink cache object
4397          *
4398          * @return BacklinkCache
4399          */
4400         function getBacklinkCache() {
4401                 if ( is_null( $this->mBacklinkCache ) ) {
4402                         $this->mBacklinkCache = new BacklinkCache( $this );
4403                 }
4404                 return $this->mBacklinkCache;
4405         }
4406
4407         /**
4408          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4409          *
4410          * @return Boolean
4411          */
4412         public function canUseNoindex() {
4413                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4414
4415                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4416                         ? $wgContentNamespaces
4417                         : $wgExemptFromUserRobotsControl;
4418
4419                 return !in_array( $this->mNamespace, $bannedNamespaces );
4420
4421         }
4422
4423         /**
4424          * Returns the raw sort key to be used for categories, with the specified
4425          * prefix.  This will be fed to Collation::getSortKey() to get a
4426          * binary sortkey that can be used for actual sorting.
4427          *
4428          * @param $prefix string The prefix to be used, specified using
4429          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4430          *   prefix.
4431          * @return string
4432          */
4433         public function getCategorySortkey( $prefix = '' ) {
4434                 $unprefixed = $this->getText();
4435
4436                 // Anything that uses this hook should only depend
4437                 // on the Title object passed in, and should probably
4438                 // tell the users to run updateCollations.php --force
4439                 // in order to re-sort existing category relations.
4440                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4441                 if ( $prefix !== '' ) {
4442                         # Separate with a line feed, so the unprefixed part is only used as
4443                         # a tiebreaker when two pages have the exact same prefix.
4444                         # In UCA, tab is the only character that can sort above LF
4445                         # so we strip both of them from the original prefix.
4446                         $prefix = strtr( $prefix, "\n\t", '  ' );
4447                         return "$prefix\n$unprefixed";
4448                 }
4449                 return $unprefixed;
4450         }
4451
4452         /**
4453          * Get the language in which the content of this page is written.
4454          * Defaults to $wgContLang, but in certain cases it can be e.g.
4455          * $wgLang (such as special pages, which are in the user language).
4456          *
4457          * @since 1.18
4458          * @return object Language
4459          */
4460         public function getPageLanguage() {
4461                 global $wgLang;
4462                 if ( $this->isSpecialPage() ) {
4463                         // special pages are in the user language
4464                         return $wgLang;
4465                 } elseif ( $this->isCssOrJsPage() ) {
4466                         // css/js should always be LTR and is, in fact, English
4467                         return wfGetLangObj( 'en' );
4468                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4469                         // Parse mediawiki messages with correct target language
4470                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4471                         return wfGetLangObj( $lang );
4472                 }
4473                 global $wgContLang;
4474                 // If nothing special, it should be in the wiki content language
4475                 $pageLang = $wgContLang;
4476                 // Hook at the end because we don't want to override the above stuff
4477                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4478                 return wfGetLangObj( $pageLang );
4479         }
4480 }