includes/Title.php

   1 <?php
   2 /**
   3  * Representation a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  *
  31  * @internal documentation reviewed 15 Mar 2010
  32  */
  33 class Title {
  34         /** @name Static cache variables */
  35         // @{
  36         static private $titleCache = array();
  37         // @}
  38
  39         /**
  40          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  41          * commonly used titles. On a batch operation this can become a memory leak
  42          * if not bounded. After hitting this many titles reset the cache.
  43          */
  44         const CACHE_MAX = 1000;
  45
  46         /**
  47          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  48          * to use the master DB
  49          */
  50         const GAID_FOR_UPDATE = 1;
  51
  52         /**
  53          * @name Private member variables
  54          * Please use the accessor functions instead.
  55          * @private
  56          */
  57         // @{
  58
  59         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  60         var $mUrlform = '';               // /< URL-encoded form of the main part
  61         var $mDbkeyform = '';             // /< Main part with underscores
  62         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  63         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  64         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  65         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  66         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  67         var $mLatestID = false;           // /< ID of most recent revision
  68         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  69         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  70         var $mOldRestrictions = false;
  71         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  72         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  73         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  74         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  75         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  76         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  77         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  78         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  79         # Don't change the following default, NS_MAIN is hardcoded in several
  80         # places.  See bug 696.
  81         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  82                                                                           # Zero except in {{transclusion}} tags
  83         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  84         var $mLength = -1;                // /< The page length, 0 for special pages
  85         var $mRedirect = null;            // /< Is the article at this title a redirect?
  86         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  87         var $mBacklinkCache = null;       // /< Cache of links to this title
  88         var $mHasSubpage;                 // /< Whether a page has any subpages
  89         // @}
  90
  91
  92         /**
  93          * Constructor
  94          */
  95         /*protected*/ function __construct() { }
  96
  97         /**
  98          * Create a new Title from a prefixed DB key
  99          *
 100          * @param $key String the database key, which has underscores
 101          *      instead of spaces, possibly including namespace and
 102          *      interwiki prefixes
 103          * @return Title, or NULL on an error
 104          */
 105         public static function newFromDBkey( $key ) {
 106                 $t = new Title();
 107                 $t->mDbkeyform = $key;
 108                 if ( $t->secureAndSplit() ) {
 109                         return $t;
 110                 } else {
 111                         return null;
 112                 }
 113         }
 114
 115         /**
 116          * Create a new Title from text, such as what one would find in a link. De-
 117          * codes any HTML entities in the text.
 118          *
 119          * @param $text String the link text; spaces, prefixes, and an
 120          *   initial ':' indicating the main namespace are accepted.
 121          * @param $defaultNamespace Int the namespace to use if none is speci-
 122          *   fied by a prefix.  If you want to force a specific namespace even if
 123          *   $text might begin with a namespace prefix, use makeTitle() or
 124          *   makeTitleSafe().
 125          * @throws MWException
 126          * @return Title|null - Title or null on an error.
 127          */
 128         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 129                 if ( is_object( $text ) ) {
 130                         throw new MWException( 'Title::newFromText given an object' );
 131                 }
 132
 133                 /**
 134                  * Wiki pages often contain multiple links to the same page.
 135                  * Title normalization and parsing can become expensive on
 136                  * pages with many links, so we can save a little time by
 137                  * caching them.
 138                  *
 139                  * In theory these are value objects and won't get changed...
 140                  */
 141                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 142                         return Title::$titleCache[$text];
 143                 }
 144
 145                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 146                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 147
 148                 $t = new Title();
 149                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 150                 $t->mDefaultNamespace = $defaultNamespace;
 151
 152                 static $cachedcount = 0 ;
 153                 if ( $t->secureAndSplit() ) {
 154                         if ( $defaultNamespace == NS_MAIN ) {
 155                                 if ( $cachedcount >= self::CACHE_MAX ) {
 156                                         # Avoid memory leaks on mass operations...
 157                                         Title::$titleCache = array();
 158                                         $cachedcount = 0;
 159                                 }
 160                                 $cachedcount++;
 161                                 Title::$titleCache[$text] =& $t;
 162                         }
 163                         return $t;
 164                 } else {
 165                         $ret = null;
 166                         return $ret;
 167                 }
 168         }
 169
 170         /**
 171          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 172          *
 173          * Example of wrong and broken code:
 174          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 175          *
 176          * Example of right code:
 177          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 178          *
 179          * Create a new Title from URL-encoded text. Ensures that
 180          * the given title's length does not exceed the maximum.
 181          *
 182          * @param $url String the title, as might be taken from a URL
 183          * @return Title the new object, or NULL on an error
 184          */
 185         public static function newFromURL( $url ) {
 186                 $t = new Title();
 187
 188                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 189                 # but some URLs used it as a space replacement and they still come
 190                 # from some external search tools.
 191                 if ( strpos( self::legalChars(), '+' ) === false ) {
 192                         $url = str_replace( '+', ' ', $url );
 193                 }
 194
 195                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 196                 if ( $t->secureAndSplit() ) {
 197                         return $t;
 198                 } else {
 199                         return null;
 200                 }
 201         }
 202
 203         /**
 204          * Create a new Title from an article ID
 205          *
 206          * @param $id Int the page_id corresponding to the Title to create
 207          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 208          * @return Title the new object, or NULL on an error
 209          */
 210         public static function newFromID( $id, $flags = 0 ) {
 211                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 212                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 213                 if ( $row !== false ) {
 214                         $title = Title::newFromRow( $row );
 215                 } else {
 216                         $title = null;
 217                 }
 218                 return $title;
 219         }
 220
 221         /**
 222          * Make an array of titles from an array of IDs
 223          *
 224          * @param $ids Array of Int Array of IDs
 225          * @return Array of Titles
 226          */
 227         public static function newFromIDs( $ids ) {
 228                 if ( !count( $ids ) ) {
 229                         return array();
 230                 }
 231                 $dbr = wfGetDB( DB_SLAVE );
 232
 233                 $res = $dbr->select(
 234                         'page',
 235                         array(
 236                                 'page_namespace', 'page_title', 'page_id',
 237                                 'page_len', 'page_is_redirect', 'page_latest',
 238                         ),
 239                         array( 'page_id' => $ids ),
 240                         __METHOD__
 241                 );
 242
 243                 $titles = array();
 244                 foreach ( $res as $row ) {
 245                         $titles[] = Title::newFromRow( $row );
 246                 }
 247                 return $titles;
 248         }
 249
 250         /**
 251          * Make a Title object from a DB row
 252          *
 253          * @param $row Object database row (needs at least page_title,page_namespace)
 254          * @return Title corresponding Title
 255          */
 256         public static function newFromRow( $row ) {
 257                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 258                 $t->loadFromRow( $row );
 259                 return $t;
 260         }
 261
 262         /**
 263          * Load Title object fields from a DB row.
 264          * If false is given, the title will be treated as non-existing.
 265          *
 266          * @param $row Object|bool database row
 267          */
 268         public function loadFromRow( $row ) {
 269                 if ( $row ) { // page found
 270                         if ( isset( $row->page_id ) )
 271                                 $this->mArticleID = (int)$row->page_id;
 272                         if ( isset( $row->page_len ) )
 273                                 $this->mLength = (int)$row->page_len;
 274                         if ( isset( $row->page_is_redirect ) )
 275                                 $this->mRedirect = (bool)$row->page_is_redirect;
 276                         if ( isset( $row->page_latest ) )
 277                                 $this->mLatestID = (int)$row->page_latest;
 278                 } else { // page not found
 279                         $this->mArticleID = 0;
 280                         $this->mLength = 0;
 281                         $this->mRedirect = false;
 282                         $this->mLatestID = 0;
 283                 }
 284         }
 285
 286         /**
 287          * Create a new Title from a namespace index and a DB key.
 288          * It's assumed that $ns and $title are *valid*, for instance when
 289          * they came directly from the database or a special page name.
 290          * For convenience, spaces are converted to underscores so that
 291          * eg user_text fields can be used directly.
 292          *
 293          * @param $ns Int the namespace of the article
 294          * @param $title String the unprefixed database key form
 295          * @param $fragment String the link fragment (after the "#")
 296          * @param $interwiki String the interwiki prefix
 297          * @return Title the new object
 298          */
 299         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 300                 $t = new Title();
 301                 $t->mInterwiki = $interwiki;
 302                 $t->mFragment = $fragment;
 303                 $t->mNamespace = $ns = intval( $ns );
 304                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 305                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 306                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 307                 $t->mTextform = str_replace( '_', ' ', $title );
 308                 return $t;
 309         }
 310
 311         /**
 312          * Create a new Title from a namespace index and a DB key.
 313          * The parameters will be checked for validity, which is a bit slower
 314          * than makeTitle() but safer for user-provided data.
 315          *
 316          * @param $ns Int the namespace of the article
 317          * @param $title String database key form
 318          * @param $fragment String the link fragment (after the "#")
 319          * @param $interwiki String interwiki prefix
 320          * @return Title the new object, or NULL on an error
 321          */
 322         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 323                 if ( !MWNamespace::exists( $ns ) ) {
 324                         return null;
 325                 }
 326
 327                 $t = new Title();
 328                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 329                 if ( $t->secureAndSplit() ) {
 330                         return $t;
 331                 } else {
 332                         return null;
 333                 }
 334         }
 335
 336         /**
 337          * Create a new Title for the Main Page
 338          *
 339          * @return Title the new object
 340          */
 341         public static function newMainPage() {
 342                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 343                 // Don't give fatal errors if the message is broken
 344                 if ( !$title ) {
 345                         $title = Title::newFromText( 'Main Page' );
 346                 }
 347                 return $title;
 348         }
 349
 350         /**
 351          * Extract a redirect destination from a string and return the
 352          * Title, or null if the text doesn't contain a valid redirect
 353          * This will only return the very next target, useful for
 354          * the redirect table and other checks that don't need full recursion
 355          *
 356          * @param $text String: Text with possible redirect
 357          * @return Title: The corresponding Title
 358          */
 359         public static function newFromRedirect( $text ) {
 360                 return self::newFromRedirectInternal( $text );
 361         }
 362
 363         /**
 364          * Extract a redirect destination from a string and return the
 365          * Title, or null if the text doesn't contain a valid redirect
 366          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 367          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 368          *
 369          * @param $text String Text with possible redirect
 370          * @return Title
 371          */
 372         public static function newFromRedirectRecurse( $text ) {
 373                 $titles = self::newFromRedirectArray( $text );
 374                 return $titles ? array_pop( $titles ) : null;
 375         }
 376
 377         /**
 378          * Extract a redirect destination from a string and return an
 379          * array of Titles, or null if the text doesn't contain a valid redirect
 380          * The last element in the array is the final destination after all redirects
 381          * have been resolved (up to $wgMaxRedirects times)
 382          *
 383          * @param $text String Text with possible redirect
 384          * @return Array of Titles, with the destination last
 385          */
 386         public static function newFromRedirectArray( $text ) {
 387                 global $wgMaxRedirects;
 388                 $title = self::newFromRedirectInternal( $text );
 389                 if ( is_null( $title ) ) {
 390                         return null;
 391                 }
 392                 // recursive check to follow double redirects
 393                 $recurse = $wgMaxRedirects;
 394                 $titles = array( $title );
 395                 while ( --$recurse > 0 ) {
 396                         if ( $title->isRedirect() ) {
 397                                 $page = WikiPage::factory( $title );
 398                                 $newtitle = $page->getRedirectTarget();
 399                         } else {
 400                                 break;
 401                         }
 402                         // Redirects to some special pages are not permitted
 403                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 404                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 405                                 $title = $newtitle;
 406                                 $titles[] = $newtitle;
 407                         } else {
 408                                 break;
 409                         }
 410                 }
 411                 return $titles;
 412         }
 413
 414         /**
 415          * Really extract the redirect destination
 416          * Do not call this function directly, use one of the newFromRedirect* functions above
 417          *
 418          * @param $text String Text with possible redirect
 419          * @return Title
 420          */
 421         protected static function newFromRedirectInternal( $text ) {
 422                 global $wgMaxRedirects;
 423                 if ( $wgMaxRedirects < 1 ) {
 424                         //redirects are disabled, so quit early
 425                         return null;
 426                 }
 427                 $redir = MagicWord::get( 'redirect' );
 428                 $text = trim( $text );
 429                 if ( $redir->matchStartAndRemove( $text ) ) {
 430                         // Extract the first link and see if it's usable
 431                         // Ensure that it really does come directly after #REDIRECT
 432                         // Some older redirects included a colon, so don't freak about that!
 433                         $m = array();
 434                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 435                                 // Strip preceding colon used to "escape" categories, etc.
 436                                 // and URL-decode links
 437                                 if ( strpos( $m[1], '%' ) !== false ) {
 438                                         // Match behavior of inline link parsing here;
 439                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 440                                 }
 441                                 $title = Title::newFromText( $m[1] );
 442                                 // If the title is a redirect to bad special pages or is invalid, return null
 443                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 444                                         return null;
 445                                 }
 446                                 return $title;
 447                         }
 448                 }
 449                 return null;
 450         }
 451
 452         /**
 453          * Get the prefixed DB key associated with an ID
 454          *
 455          * @param $id Int the page_id of the article
 456          * @return Title an object representing the article, or NULL if no such article was found
 457          */
 458         public static function nameOf( $id ) {
 459                 $dbr = wfGetDB( DB_SLAVE );
 460
 461                 $s = $dbr->selectRow(
 462                         'page',
 463                         array( 'page_namespace', 'page_title' ),
 464                         array( 'page_id' => $id ),
 465                         __METHOD__
 466                 );
 467                 if ( $s === false ) {
 468                         return null;
 469                 }
 470
 471                 $n = self::makeName( $s->page_namespace, $s->page_title );
 472                 return $n;
 473         }
 474
 475         /**
 476          * Get a regex character class describing the legal characters in a link
 477          *
 478          * @return String the list of characters, not delimited
 479          */
 480         public static function legalChars() {
 481                 global $wgLegalTitleChars;
 482                 return $wgLegalTitleChars;
 483         }
 484
 485         /**
 486          * Returns a simple regex that will match on characters and sequences invalid in titles.
 487          * Note that this doesn't pick up many things that could be wrong with titles, but that
 488          * replacing this regex with something valid will make many titles valid.
 489          *
 490          * @return String regex string
 491          */
 492         static function getTitleInvalidRegex() {
 493                 static $rxTc = false;
 494                 if ( !$rxTc ) {
 495                         # Matching titles will be held as illegal.
 496                         $rxTc = '/' .
 497                                 # Any character not allowed is forbidden...
 498                                 '[^' . self::legalChars() . ']' .
 499                                 # URL percent encoding sequences interfere with the ability
 500                                 # to round-trip titles -- you can't link to them consistently.
 501                                 '|%[0-9A-Fa-f]{2}' .
 502                                 # XML/HTML character references produce similar issues.
 503                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 504                                 '|&#[0-9]+;' .
 505                                 '|&#x[0-9A-Fa-f]+;' .
 506                                 '/S';
 507                 }
 508
 509                 return $rxTc;
 510         }
 511
 512         /**
 513          * Get a string representation of a title suitable for
 514          * including in a search index
 515          *
 516          * @param $ns Int a namespace index
 517          * @param $title String text-form main part
 518          * @return String a stripped-down title string ready for the search index
 519          */
 520         public static function indexTitle( $ns, $title ) {
 521                 global $wgContLang;
 522
 523                 $lc = SearchEngine::legalSearchChars() . '&#;';
 524                 $t = $wgContLang->normalizeForSearch( $title );
 525                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 526                 $t = $wgContLang->lc( $t );
 527
 528                 # Handle 's, s'
 529                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 530                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 531
 532                 $t = preg_replace( "/\\s+/", ' ', $t );
 533
 534                 if ( $ns == NS_FILE ) {
 535                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 536                 }
 537                 return trim( $t );
 538         }
 539
 540         /**
 541          * Make a prefixed DB key from a DB key and a namespace index
 542          *
 543          * @param $ns Int numerical representation of the namespace
 544          * @param $title String the DB key form the title
 545          * @param $fragment String The link fragment (after the "#")
 546          * @param $interwiki String The interwiki prefix
 547          * @return String the prefixed form of the title
 548          */
 549         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 550                 global $wgContLang;
 551
 552                 $namespace = $wgContLang->getNsText( $ns );
 553                 $name = $namespace == '' ? $title : "$namespace:$title";
 554                 if ( strval( $interwiki ) != '' ) {
 555                         $name = "$interwiki:$name";
 556                 }
 557                 if ( strval( $fragment ) != '' ) {
 558                         $name .= '#' . $fragment;
 559                 }
 560                 return $name;
 561         }
 562
 563         /**
 564          * Escape a text fragment, say from a link, for a URL
 565          *
 566          * @param $fragment string containing a URL or link fragment (after the "#")
 567          * @return String: escaped string
 568          */
 569         static function escapeFragmentForURL( $fragment ) {
 570                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 571                 # fragments appear not to work in IE (at least up to 7) or in at least
 572                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 573                 # to care if they aren't encoded.
 574                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 575         }
 576
 577         /**
 578          * Callback for usort() to do title sorts by (namespace, title)
 579          *
 580          * @param $a Title
 581          * @param $b Title
 582          *
 583          * @return Integer: result of string comparison, or namespace comparison
 584          */
 585         public static function compare( $a, $b ) {
 586                 if ( $a->getNamespace() == $b->getNamespace() ) {
 587                         return strcmp( $a->getText(), $b->getText() );
 588                 } else {
 589                         return $a->getNamespace() - $b->getNamespace();
 590                 }
 591         }
 592
 593         /**
 594          * Determine whether the object refers to a page within
 595          * this project.
 596          *
 597          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 598          */
 599         public function isLocal() {
 600                 if ( $this->mInterwiki != '' ) {
 601                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 602                 } else {
 603                         return true;
 604                 }
 605         }
 606
 607         /**
 608          * Is this Title interwiki?
 609          *
 610          * @return Bool
 611          */
 612         public function isExternal() {
 613                 return ( $this->mInterwiki != '' );
 614         }
 615
 616         /**
 617          * Get the interwiki prefix (or null string)
 618          *
 619          * @return String Interwiki prefix
 620          */
 621         public function getInterwiki() {
 622                 return $this->mInterwiki;
 623         }
 624
 625         /**
 626          * Determine whether the object refers to a page within
 627          * this project and is transcludable.
 628          *
 629          * @return Bool TRUE if this is transcludable
 630          */
 631         public function isTrans() {
 632                 if ( $this->mInterwiki == '' ) {
 633                         return false;
 634                 }
 635
 636                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 637         }
 638
 639         /**
 640          * Returns the DB name of the distant wiki which owns the object.
 641          *
 642          * @return String the DB name
 643          */
 644         public function getTransWikiID() {
 645                 if ( $this->mInterwiki == '' ) {
 646                         return false;
 647                 }
 648
 649                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 650         }
 651
 652         /**
 653          * Get the text form (spaces not underscores) of the main part
 654          *
 655          * @return String Main part of the title
 656          */
 657         public function getText() {
 658                 return $this->mTextform;
 659         }
 660
 661         /**
 662          * Get the URL-encoded form of the main part
 663          *
 664          * @return String Main part of the title, URL-encoded
 665          */
 666         public function getPartialURL() {
 667                 return $this->mUrlform;
 668         }
 669
 670         /**
 671          * Get the main part with underscores
 672          *
 673          * @return String: Main part of the title, with underscores
 674          */
 675         public function getDBkey() {
 676                 return $this->mDbkeyform;
 677         }
 678
 679         /**
 680          * Get the DB key with the initial letter case as specified by the user
 681          *
 682          * @return String DB key
 683          */
 684         function getUserCaseDBKey() {
 685                 return $this->mUserCaseDBKey;
 686         }
 687
 688         /**
 689          * Get the namespace index, i.e. one of the NS_xxxx constants.
 690          *
 691          * @return Integer: Namespace index
 692          */
 693         public function getNamespace() {
 694                 return $this->mNamespace;
 695         }
 696
 697         /**
 698          * Get the namespace text
 699          *
 700          * @return String: Namespace text
 701          */
 702         public function getNsText() {
 703                 global $wgContLang;
 704
 705                 if ( $this->mInterwiki != '' ) {
 706                         // This probably shouldn't even happen. ohh man, oh yuck.
 707                         // But for interwiki transclusion it sometimes does.
 708                         // Shit. Shit shit shit.
 709                         //
 710                         // Use the canonical namespaces if possible to try to
 711                         // resolve a foreign namespace.
 712                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 713                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 714                         }
 715                 }
 716
 717                 if ( $wgContLang->needsGenderDistinction() &&
 718                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 719                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 720                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 721                 }
 722
 723                 return $wgContLang->getNsText( $this->mNamespace );
 724         }
 725
 726         /**
 727          * Get the namespace text of the subject (rather than talk) page
 728          *
 729          * @return String Namespace text
 730          */
 731         public function getSubjectNsText() {
 732                 global $wgContLang;
 733                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 734         }
 735
 736         /**
 737          * Get the namespace text of the talk page
 738          *
 739          * @return String Namespace text
 740          */
 741         public function getTalkNsText() {
 742                 global $wgContLang;
 743                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 744         }
 745
 746         /**
 747          * Could this title have a corresponding talk page?
 748          *
 749          * @return Bool TRUE or FALSE
 750          */
 751         public function canTalk() {
 752                 return( MWNamespace::canTalk( $this->mNamespace ) );
 753         }
 754
 755         /**
 756          * Is this in a namespace that allows actual pages?
 757          *
 758          * @return Bool
 759          * @internal note -- uses hardcoded namespace index instead of constants
 760          */
 761         public function canExist() {
 762                 return $this->mNamespace >= NS_MAIN;
 763         }
 764
 765         /**
 766          * Can this title be added to a user's watchlist?
 767          *
 768          * @return Bool TRUE or FALSE
 769          */
 770         public function isWatchable() {
 771                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 772         }
 773
 774         /**
 775          * Returns true if this is a special page.
 776          *
 777          * @return boolean
 778          */
 779         public function isSpecialPage() {
 780                 return $this->getNamespace() == NS_SPECIAL;
 781         }
 782
 783         /**
 784          * Returns true if this title resolves to the named special page
 785          *
 786          * @param $name String The special page name
 787          * @return boolean
 788          */
 789         public function isSpecial( $name ) {
 790                 if ( $this->isSpecialPage() ) {
 791                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 792                         if ( $name == $thisName ) {
 793                                 return true;
 794                         }
 795                 }
 796                 return false;
 797         }
 798
 799         /**
 800          * If the Title refers to a special page alias which is not the local default, resolve
 801          * the alias, and localise the name as necessary.  Otherwise, return $this
 802          *
 803          * @return Title
 804          */
 805         public function fixSpecialName() {
 806                 if ( $this->isSpecialPage() ) {
 807                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 808                         if ( $canonicalName ) {
 809                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 810                                 if ( $localName != $this->mDbkeyform ) {
 811                                         return Title::makeTitle( NS_SPECIAL, $localName );
 812                                 }
 813                         }
 814                 }
 815                 return $this;
 816         }
 817
 818         /**
 819          * Returns true if the title is inside the specified namespace.
 820          *
 821          * Please make use of this instead of comparing to getNamespace()
 822          * This function is much more resistant to changes we may make
 823          * to namespaces than code that makes direct comparisons.
 824          * @param $ns int The namespace
 825          * @return bool
 826          * @since 1.19
 827          */
 828         public function inNamespace( $ns ) {
 829                 return MWNamespace::equals( $this->getNamespace(), $ns );
 830         }
 831
 832         /**
 833          * Returns true if the title is inside one of the specified namespaces.
 834          *
 835          * @param ...$namespaces The namespaces to check for
 836          * @return bool
 837          * @since 1.19
 838          */
 839         public function inNamespaces( /* ... */ ) {
 840                 $namespaces = func_get_args();
 841                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 842                         $namespaces = $namespaces[0];
 843                 }
 844
 845                 foreach ( $namespaces as $ns ) {
 846                         if ( $this->inNamespace( $ns ) ) {
 847                                 return true;
 848                         }
 849                 }
 850
 851                 return false;
 852         }
 853
 854         /**
 855          * Returns true if the title has the same subject namespace as the
 856          * namespace specified.
 857          * For example this method will take NS_USER and return true if namespace
 858          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 859          * as their subject namespace.
 860          *
 861          * This is MUCH simpler than individually testing for equivilance
 862          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 863          * @since 1.19
 864          * @param $ns int
 865          * @return bool
 866          */
 867         public function hasSubjectNamespace( $ns ) {
 868                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 869         }
 870
 871         /**
 872          * Is this Title in a namespace which contains content?
 873          * In other words, is this a content page, for the purposes of calculating
 874          * statistics, etc?
 875          *
 876          * @return Boolean
 877          */
 878         public function isContentPage() {
 879                 return MWNamespace::isContent( $this->getNamespace() );
 880         }
 881
 882         /**
 883          * Would anybody with sufficient privileges be able to move this page?
 884          * Some pages just aren't movable.
 885          *
 886          * @return Bool TRUE or FALSE
 887          */
 888         public function isMovable() {
 889                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 890                         // Interwiki title or immovable namespace. Hooks don't get to override here
 891                         return false;
 892                 }
 893
 894                 $result = true;
 895                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 896                 return $result;
 897         }
 898
 899         /**
 900          * Is this the mainpage?
 901          * @note Title::newFromText seams to be sufficiently optimized by the title
 902          * cache that we don't need to over-optimize by doing direct comparisons and
 903          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 904          * ends up reporting something differently than $title->isMainPage();
 905          *
 906          * @since 1.18
 907          * @return Bool
 908          */
 909         public function isMainPage() {
 910                 return $this->equals( Title::newMainPage() );
 911         }
 912
 913         /**
 914          * Is this a subpage?
 915          *
 916          * @return Bool
 917          */
 918         public function isSubpage() {
 919                 return MWNamespace::hasSubpages( $this->mNamespace )
 920                         ? strpos( $this->getText(), '/' ) !== false
 921                         : false;
 922         }
 923
 924         /**
 925          * Is this a conversion table for the LanguageConverter?
 926          *
 927          * @return Bool
 928          */
 929         public function isConversionTable() {
 930                 return $this->getNamespace() == NS_MEDIAWIKI &&
 931                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 932         }
 933
 934         /**
 935          * Does that page contain wikitext, or it is JS, CSS or whatever?
 936          *
 937          * @return Bool
 938          */
 939         public function isWikitextPage() {
 940                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
 941                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
 942                 return $retval;
 943         }
 944
 945         /**
 946          * Could this page contain custom CSS or JavaScript, based
 947          * on the title?
 948          *
 949          * @return Bool
 950          */
 951         public function isCssOrJsPage() {
 952                 $retval = $this->mNamespace == NS_MEDIAWIKI
 953                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
 954                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
 955                 return $retval;
 956         }
 957
 958         /**
 959          * Is this a .css or .js subpage of a user page?
 960          * @return Bool
 961          */
 962         public function isCssJsSubpage() {
 963                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
 964         }
 965
 966         /**
 967          * Trim down a .css or .js subpage title to get the corresponding skin name
 968          *
 969          * @return string containing skin name from .css or .js subpage title
 970          */
 971         public function getSkinFromCssJsSubpage() {
 972                 $subpage = explode( '/', $this->mTextform );
 973                 $subpage = $subpage[ count( $subpage ) - 1 ];
 974                 $lastdot = strrpos( $subpage, '.' );
 975                 if ( $lastdot === false )
 976                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 977                 return substr( $subpage, 0, $lastdot );
 978         }
 979
 980         /**
 981          * Is this a .css subpage of a user page?
 982          *
 983          * @return Bool
 984          */
 985         public function isCssSubpage() {
 986                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
 987         }
 988
 989         /**
 990          * Is this a .js subpage of a user page?
 991          *
 992          * @return Bool
 993          */
 994         public function isJsSubpage() {
 995                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
 996         }
 997
 998         /**
 999          * Is this a talk page of some sort?
1000          *
1001          * @return Bool
1002          */
1003         public function isTalkPage() {
1004                 return MWNamespace::isTalk( $this->getNamespace() );
1005         }
1006
1007         /**
1008          * Get a Title object associated with the talk page of this article
1009          *
1010          * @return Title the object for the talk page
1011          */
1012         public function getTalkPage() {
1013                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1014         }
1015
1016         /**
1017          * Get a title object associated with the subject page of this
1018          * talk page
1019          *
1020          * @return Title the object for the subject page
1021          */
1022         public function getSubjectPage() {
1023                 // Is this the same title?
1024                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1025                 if ( $this->getNamespace() == $subjectNS ) {
1026                         return $this;
1027                 }
1028                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1029         }
1030
1031         /**
1032          * Get the default namespace index, for when there is no namespace
1033          *
1034          * @return Int Default namespace index
1035          */
1036         public function getDefaultNamespace() {
1037                 return $this->mDefaultNamespace;
1038         }
1039
1040         /**
1041          * Get title for search index
1042          *
1043          * @return String a stripped-down title string ready for the
1044          *  search index
1045          */
1046         public function getIndexTitle() {
1047                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1048         }
1049
1050         /**
1051          * Get the Title fragment (i.e.\ the bit after the #) in text form
1052          *
1053          * @return String Title fragment
1054          */
1055         public function getFragment() {
1056                 return $this->mFragment;
1057         }
1058
1059         /**
1060          * Get the fragment in URL form, including the "#" character if there is one
1061          * @return String Fragment in URL form
1062          */
1063         public function getFragmentForURL() {
1064                 if ( $this->mFragment == '' ) {
1065                         return '';
1066                 } else {
1067                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1068                 }
1069         }
1070
1071         /**
1072          * Set the fragment for this title. Removes the first character from the
1073          * specified fragment before setting, so it assumes you're passing it with
1074          * an initial "#".
1075          *
1076          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1077          * Still in active use privately.
1078          *
1079          * @param $fragment String text
1080          */
1081         public function setFragment( $fragment ) {
1082                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1083         }
1084
1085         /**
1086          * Prefix some arbitrary text with the namespace or interwiki prefix
1087          * of this object
1088          *
1089          * @param $name String the text
1090          * @return String the prefixed text
1091          * @private
1092          */
1093         private function prefix( $name ) {
1094                 $p = '';
1095                 if ( $this->mInterwiki != '' ) {
1096                         $p = $this->mInterwiki . ':';
1097                 }
1098
1099                 if ( 0 != $this->mNamespace ) {
1100                         $p .= $this->getNsText() . ':';
1101                 }
1102                 return $p . $name;
1103         }
1104
1105         /**
1106          * Get the prefixed database key form
1107          *
1108          * @return String the prefixed title, with underscores and
1109          *  any interwiki and namespace prefixes
1110          */
1111         public function getPrefixedDBkey() {
1112                 $s = $this->prefix( $this->mDbkeyform );
1113                 $s = str_replace( ' ', '_', $s );
1114                 return $s;
1115         }
1116
1117         /**
1118          * Get the prefixed title with spaces.
1119          * This is the form usually used for display
1120          *
1121          * @return String the prefixed title, with spaces
1122          */
1123         public function getPrefixedText() {
1124                 // @todo FIXME: Bad usage of empty() ?
1125                 if ( empty( $this->mPrefixedText ) ) {
1126                         $s = $this->prefix( $this->mTextform );
1127                         $s = str_replace( '_', ' ', $s );
1128                         $this->mPrefixedText = $s;
1129                 }
1130                 return $this->mPrefixedText;
1131         }
1132
1133         /**
1134          * Return a string representation of this title
1135          *
1136          * @return String representation of this title
1137          */
1138         public function __toString() {
1139                 return $this->getPrefixedText();
1140         }
1141
1142         /**
1143          * Get the prefixed title with spaces, plus any fragment
1144          * (part beginning with '#')
1145          *
1146          * @return String the prefixed title, with spaces and the fragment, including '#'
1147          */
1148         public function getFullText() {
1149                 $text = $this->getPrefixedText();
1150                 if ( $this->mFragment != '' ) {
1151                         $text .= '#' . $this->mFragment;
1152                 }
1153                 return $text;
1154         }
1155
1156         /**
1157          * Get the base page name, i.e. the leftmost part before any slashes
1158          *
1159          * @return String Base name
1160          */
1161         public function getBaseText() {
1162                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1163                         return $this->getText();
1164                 }
1165
1166                 $parts = explode( '/', $this->getText() );
1167                 # Don't discard the real title if there's no subpage involved
1168                 if ( count( $parts ) > 1 ) {
1169                         unset( $parts[count( $parts ) - 1] );
1170                 }
1171                 return implode( '/', $parts );
1172         }
1173
1174         /**
1175          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1176          *
1177          * @return String Subpage name
1178          */
1179         public function getSubpageText() {
1180                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1181                         return( $this->mTextform );
1182                 }
1183                 $parts = explode( '/', $this->mTextform );
1184                 return( $parts[count( $parts ) - 1] );
1185         }
1186
1187         /**
1188          * Get the HTML-escaped displayable text form.
1189          * Used for the title field in <a> tags.
1190          *
1191          * @return String the text, including any prefixes
1192          */
1193         public function getEscapedText() {
1194                 wfDeprecated( __METHOD__, '1.19' );
1195                 return htmlspecialchars( $this->getPrefixedText() );
1196         }
1197
1198         /**
1199          * Get a URL-encoded form of the subpage text
1200          *
1201          * @return String URL-encoded subpage name
1202          */
1203         public function getSubpageUrlForm() {
1204                 $text = $this->getSubpageText();
1205                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1206                 return( $text );
1207         }
1208
1209         /**
1210          * Get a URL-encoded title (not an actual URL) including interwiki
1211          *
1212          * @return String the URL-encoded form
1213          */
1214         public function getPrefixedURL() {
1215                 $s = $this->prefix( $this->mDbkeyform );
1216                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1217                 return $s;
1218         }
1219
1220         /**
1221          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1222          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1223          * second argument named variant. This was deprecated in favor
1224          * of passing an array of option with a "variant" key
1225          * Once $query2 is removed for good, this helper can be dropped
1226          * andthe wfArrayToCGI moved to getLocalURL();
1227          *
1228          * @since 1.19 (r105919)
1229          * @param $query
1230          * @param $query2 bool
1231          * @return String
1232          */
1233         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1234                 if( $query2 !== false ) {
1235                         wfDeprecated( "Title::get{Canonical,Full,Link,Local} method called with a second parameter is deprecated. Add your parameter to an array passed as the first parameter.", "1.19" );
1236                 }
1237                 if ( is_array( $query ) ) {
1238                         $query = wfArrayToCGI( $query );
1239                 }
1240                 if ( $query2 ) {
1241                         if ( is_string( $query2 ) ) {
1242                                 // $query2 is a string, we will consider this to be
1243                                 // a deprecated $variant argument and add it to the query
1244                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1245                         } else {
1246                                 $query2 = wfArrayToCGI( $query2 );
1247                         }
1248                         // If we have $query content add a & to it first
1249                         if ( $query ) {
1250                                 $query .= '&';
1251                         }
1252                         // Now append the queries together
1253                         $query .= $query2;
1254                 }
1255                 return $query;
1256         }
1257
1258         /**
1259          * Get a real URL referring to this title, with interwiki link and
1260          * fragment
1261          *
1262          * See getLocalURL for the arguments.
1263          *
1264          * @see self::getLocalURL
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
1290          * @param $query string|array an optional query string,
1291          *   not used for interwiki     links. Can be specified as an associative array as well,
1292          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1293          *   Some query patterns will trigger various shorturl path replacements.
1294          * @param $query2 Mixed: An optional secondary query array. This one MUST
1295          *   be an array. If a string is passed it will be interpreted as a deprecated
1296          *   variant argument and urlencoded into a variant= argument.
1297          *   This second query argument will be added to the $query
1298          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1299          *   pair in the first parameter array instead.
1300          *
1301          * @return String the URL
1302          */
1303         public function getLocalURL( $query = '', $query2 = false ) {
1304                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1305
1306                 $query = self::fixUrlQueryArgs( $query, $query2 );
1307
1308                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1309                 if ( $interwiki ) {
1310                         $namespace = $this->getNsText();
1311                         if ( $namespace != '' ) {
1312                                 # Can this actually happen? Interwikis shouldn't be parsed.
1313                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1314                                 $namespace .= ':';
1315                         }
1316                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1317                         $url = wfAppendQuery( $url, $query );
1318                 } else {
1319                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1320                         if ( $query == '' ) {
1321                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1322                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1323                         } else {
1324                                 global $wgVariantArticlePath, $wgActionPaths;
1325                                 $url = false;
1326                                 $matches = array();
1327
1328                                 if ( !empty( $wgActionPaths ) &&
1329                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1330                                 {
1331                                         $action = urldecode( $matches[2] );
1332                                         if ( isset( $wgActionPaths[$action] ) ) {
1333                                                 $query = $matches[1];
1334                                                 if ( isset( $matches[4] ) ) {
1335                                                         $query .= $matches[4];
1336                                                 }
1337                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1338                                                 if ( $query != '' ) {
1339                                                         $url = wfAppendQuery( $url, $query );
1340                                                 }
1341                                         }
1342                                 }
1343
1344                                 if ( $url === false &&
1345                                         $wgVariantArticlePath &&
1346                                         $this->getPageLanguage()->hasVariants() &&
1347                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1348                                 {
1349                                         $variant = urldecode( $matches[1] );
1350                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1351                                                 // Only do the variant replacement if the given variant is a valid
1352                                                 // variant for the page's language.
1353                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1354                                                 $url = str_replace( '$1', $dbkey, $url );
1355                                         }
1356                                 }
1357
1358                                 if ( $url === false ) {
1359                                         if ( $query == '-' ) {
1360                                                 $query = '';
1361                                         }
1362                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1363                                 }
1364                         }
1365
1366                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1367
1368                         // @todo FIXME: This causes breakage in various places when we
1369                         // actually expected a local URL and end up with dupe prefixes.
1370                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1371                                 $url = $wgServer . $url;
1372                         }
1373                 }
1374                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1375                 return $url;
1376         }
1377
1378         /**
1379          * Get a URL that's the simplest URL that will be valid to link, locally,
1380          * to the current Title.  It includes the fragment, but does not include
1381          * the server unless action=render is used (or the link is external).  If
1382          * there's a fragment but the prefixed text is empty, we just return a link
1383          * to the fragment.
1384          *
1385          * The result obviously should not be URL-escaped, but does need to be
1386          * HTML-escaped if it's being output in HTML.
1387          *
1388          * See getLocalURL for the arguments.
1389          *
1390          * @see self::getLocalURL
1391          * @return String the URL
1392          */
1393         public function getLinkURL( $query = '', $query2 = false ) {
1394                 wfProfileIn( __METHOD__ );
1395                 if ( $this->isExternal() ) {
1396                         $ret = $this->getFullURL( $query, $query2 );
1397                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1398                         $ret = $this->getFragmentForURL();
1399                 } else {
1400                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1401                 }
1402                 wfProfileOut( __METHOD__ );
1403                 return $ret;
1404         }
1405
1406         /**
1407          * Get an HTML-escaped version of the URL form, suitable for
1408          * using in a link, without a server name or fragment
1409          *
1410          * See getLocalURL for the arguments.
1411          *
1412          * @see self::getLocalURL
1413          * @param $query string
1414          * @param $query2 bool|string
1415          * @return String the URL
1416          */
1417         public function escapeLocalURL( $query = '', $query2 = false ) {
1418                 wfDeprecated( __METHOD__, '1.19' );
1419                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1420         }
1421
1422         /**
1423          * Get an HTML-escaped version of the URL form, suitable for
1424          * using in a link, including the server name and fragment
1425          *
1426          * See getLocalURL for the arguments.
1427          *
1428          * @see self::getLocalURL
1429          * @return String the URL
1430          */
1431         public function escapeFullURL( $query = '', $query2 = false ) {
1432                 wfDeprecated( __METHOD__, '1.19' );
1433                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1434         }
1435
1436         /**
1437          * Get the URL form for an internal link.
1438          * - Used in various Squid-related code, in case we have a different
1439          * internal hostname for the server from the exposed one.
1440          *
1441          * This uses $wgInternalServer to qualify the path, or $wgServer
1442          * if $wgInternalServer is not set. If the server variable used is
1443          * protocol-relative, the URL will be expanded to http://
1444          *
1445          * See getLocalURL for the arguments.
1446          *
1447          * @see self::getLocalURL
1448          * @return String the URL
1449          */
1450         public function getInternalURL( $query = '', $query2 = false ) {
1451                 global $wgInternalServer, $wgServer;
1452                 $query = self::fixUrlQueryArgs( $query, $query2 );
1453                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1454                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1455                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1456                 return $url;
1457         }
1458
1459         /**
1460          * Get the URL for a canonical link, for use in things like IRC and
1461          * e-mail notifications. Uses $wgCanonicalServer and the
1462          * GetCanonicalURL hook.
1463          *
1464          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1465          *
1466          * See getLocalURL for the arguments.
1467          *
1468          * @see self::getLocalURL
1469          * @return string The URL
1470          * @since 1.18
1471          */
1472         public function getCanonicalURL( $query = '', $query2 = false ) {
1473                 $query = self::fixUrlQueryArgs( $query, $query2 );
1474                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1475                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1476                 return $url;
1477         }
1478
1479         /**
1480          * HTML-escaped version of getCanonicalURL()
1481          *
1482          * See getLocalURL for the arguments.
1483          *
1484          * @see self::getLocalURL
1485          * @since 1.18
1486          * @return string
1487          */
1488         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1489                 wfDeprecated( __METHOD__, '1.19' );
1490                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1491         }
1492
1493         /**
1494          * Get the edit URL for this Title
1495          *
1496          * @return String the URL, or a null string if this is an
1497          *  interwiki link
1498          */
1499         public function getEditURL() {
1500                 if ( $this->mInterwiki != '' ) {
1501                         return '';
1502                 }
1503                 $s = $this->getLocalURL( 'action=edit' );
1504
1505                 return $s;
1506         }
1507
1508         /**
1509          * Is $wgUser watching this page?
1510          *
1511          * @return Bool
1512          */
1513         public function userIsWatching() {
1514                 global $wgUser;
1515
1516                 if ( is_null( $this->mWatched ) ) {
1517                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1518                                 $this->mWatched = false;
1519                         } else {
1520                                 $this->mWatched = $wgUser->isWatched( $this );
1521                         }
1522                 }
1523                 return $this->mWatched;
1524         }
1525
1526         /**
1527          * Can $wgUser read this page?
1528          *
1529          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1530          * @return Bool
1531          * @todo fold these checks into userCan()
1532          */
1533         public function userCanRead() {
1534                 wfDeprecated( __METHOD__, '1.19' );
1535                 return $this->userCan( 'read' );
1536         }
1537
1538         /**
1539          * Can $user perform $action on this page?
1540          * This skips potentially expensive cascading permission checks
1541          * as well as avoids expensive error formatting
1542          *
1543          * Suitable for use for nonessential UI controls in common cases, but
1544          * _not_ for functional access control.
1545          *
1546          * May provide false positives, but should never provide a false negative.
1547          *
1548          * @param $action String action that permission needs to be checked for
1549          * @param $user User to check (since 1.19); $wgUser will be used if not
1550          *              provided.
1551          * @return Bool
1552          */
1553         public function quickUserCan( $action, $user = null ) {
1554                 return $this->userCan( $action, $user, false );
1555         }
1556
1557         /**
1558          * Can $user perform $action on this page?
1559          *
1560          * @param $action String action that permission needs to be checked for
1561          * @param $user User to check (since 1.19); $wgUser will be used if not
1562          *   provided.
1563          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1564          *   unnecessary queries.
1565          * @return Bool
1566          */
1567         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1568                 if ( !$user instanceof User ) {
1569                         global $wgUser;
1570                         $user = $wgUser;
1571                 }
1572                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1573         }
1574
1575         /**
1576          * Can $user perform $action on this page?
1577          *
1578          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1579          *
1580          * @param $action String action that permission needs to be checked for
1581          * @param $user User to check
1582          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1583          *   queries by skipping checks for cascading protections and user blocks.
1584          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1585          *   whose corresponding errors may be ignored.
1586          * @return Array of arguments to wfMsg to explain permissions problems.
1587          */
1588         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1589                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1590
1591                 // Remove the errors being ignored.
1592                 foreach ( $errors as $index => $error ) {
1593                         $error_key = is_array( $error ) ? $error[0] : $error;
1594
1595                         if ( in_array( $error_key, $ignoreErrors ) ) {
1596                                 unset( $errors[$index] );
1597                         }
1598                 }
1599
1600                 return $errors;
1601         }
1602
1603         /**
1604          * Permissions checks that fail most often, and which are easiest to test.
1605          *
1606          * @param $action String the action to check
1607          * @param $user User user to check
1608          * @param $errors Array list of current errors
1609          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1610          * @param $short Boolean short circuit on first error
1611          *
1612          * @return Array list of errors
1613          */
1614         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1615                 if ( $action == 'create' ) {
1616                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1617                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1618                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1619                         }
1620                 } elseif ( $action == 'move' ) {
1621                         if ( !$user->isAllowed( 'move-rootuserpages' )
1622                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1623                                 // Show user page-specific message only if the user can move other pages
1624                                 $errors[] = array( 'cant-move-user-page' );
1625                         }
1626
1627                         // Check if user is allowed to move files if it's a file
1628                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1629                                 $errors[] = array( 'movenotallowedfile' );
1630                         }
1631
1632                         if ( !$user->isAllowed( 'move' ) ) {
1633                                 // User can't move anything
1634                                 global $wgGroupPermissions;
1635                                 $userCanMove = false;
1636                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1637                                         $userCanMove = $wgGroupPermissions['user']['move'];
1638                                 }
1639                                 $autoconfirmedCanMove = false;
1640                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1641                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1642                                 }
1643                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1644                                         // custom message if logged-in users without any special rights can move
1645                                         $errors[] = array( 'movenologintext' );
1646                                 } else {
1647                                         $errors[] = array( 'movenotallowed' );
1648                                 }
1649                         }
1650                 } elseif ( $action == 'move-target' ) {
1651                         if ( !$user->isAllowed( 'move' ) ) {
1652                                 // User can't move anything
1653                                 $errors[] = array( 'movenotallowed' );
1654                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1655                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1656                                 // Show user page-specific message only if the user can move other pages
1657                                 $errors[] = array( 'cant-move-to-user-page' );
1658                         }
1659                 } elseif ( !$user->isAllowed( $action ) ) {
1660                         $errors[] = $this->missingPermissionError( $action, $short );
1661                 }
1662
1663                 return $errors;
1664         }
1665
1666         /**
1667          * Add the resulting error code to the errors array
1668          *
1669          * @param $errors Array list of current errors
1670          * @param $result Mixed result of errors
1671          *
1672          * @return Array list of errors
1673          */
1674         private function resultToError( $errors, $result ) {
1675                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1676                         // A single array representing an error
1677                         $errors[] = $result;
1678                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1679                         // A nested array representing multiple errors
1680                         $errors = array_merge( $errors, $result );
1681                 } elseif ( $result !== '' && is_string( $result ) ) {
1682                         // A string representing a message-id
1683                         $errors[] = array( $result );
1684                 } elseif ( $result === false ) {
1685                         // a generic "We don't want them to do that"
1686                         $errors[] = array( 'badaccess-group0' );
1687                 }
1688                 return $errors;
1689         }
1690
1691         /**
1692          * Check various permission hooks
1693          *
1694          * @param $action String the action to check
1695          * @param $user User user to check
1696          * @param $errors Array list of current errors
1697          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1698          * @param $short Boolean short circuit on first error
1699          *
1700          * @return Array list of errors
1701          */
1702         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1703                 // Use getUserPermissionsErrors instead
1704                 $result = '';
1705                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1706                         return $result ? array() : array( array( 'badaccess-group0' ) );
1707                 }
1708                 // Check getUserPermissionsErrors hook
1709                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1710                         $errors = $this->resultToError( $errors, $result );
1711                 }
1712                 // Check getUserPermissionsErrorsExpensive hook
1713                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1714                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1715                         $errors = $this->resultToError( $errors, $result );
1716                 }
1717
1718                 return $errors;
1719         }
1720
1721         /**
1722          * Check permissions on special pages & namespaces
1723          *
1724          * @param $action String the action to check
1725          * @param $user User user to check
1726          * @param $errors Array list of current errors
1727          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1728          * @param $short Boolean short circuit on first error
1729          *
1730          * @return Array list of errors
1731          */
1732         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1733                 # Only 'createaccount' and 'execute' can be performed on
1734                 # special pages, which don't actually exist in the DB.
1735                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1736                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1737                         $errors[] = array( 'ns-specialprotected' );
1738                 }
1739
1740                 # Check $wgNamespaceProtection for restricted namespaces
1741                 if ( $this->isNamespaceProtected( $user ) ) {
1742                         $ns = $this->mNamespace == NS_MAIN ?
1743                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1744                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1745                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1746                 }
1747
1748                 return $errors;
1749         }
1750
1751         /**
1752          * Check CSS/JS sub-page permissions
1753          *
1754          * @param $action String the action to check
1755          * @param $user User user to check
1756          * @param $errors Array list of current errors
1757          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1758          * @param $short Boolean short circuit on first error
1759          *
1760          * @return Array list of errors
1761          */
1762         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1763                 # Protect css/js subpages of user pages
1764                 # XXX: this might be better using restrictions
1765                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1766                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1767                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1768                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1769                                 $errors[] = array( 'customcssprotected' );
1770                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1771                                 $errors[] = array( 'customjsprotected' );
1772                         }
1773                 }
1774
1775                 return $errors;
1776         }
1777
1778         /**
1779          * Check against page_restrictions table requirements on this
1780          * page. The user must possess all required rights for this
1781          * action.
1782          *
1783          * @param $action String the action to check
1784          * @param $user User user to check
1785          * @param $errors Array list of current errors
1786          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1787          * @param $short Boolean short circuit on first error
1788          *
1789          * @return Array list of errors
1790          */
1791         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1792                 foreach ( $this->getRestrictions( $action ) as $right ) {
1793                         // Backwards compatibility, rewrite sysop -> protect
1794                         if ( $right == 'sysop' ) {
1795                                 $right = 'protect';
1796                         }
1797                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1798                                 // Users with 'editprotected' permission can edit protected pages
1799                                 // without cascading option turned on.
1800                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1801                                         || $this->mCascadeRestriction )
1802                                 {
1803                                         $errors[] = array( 'protectedpagetext', $right );
1804                                 }
1805                         }
1806                 }
1807
1808                 return $errors;
1809         }
1810
1811         /**
1812          * Check restrictions on cascading pages.
1813          *
1814          * @param $action String the action to check
1815          * @param $user User to check
1816          * @param $errors Array list of current errors
1817          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1818          * @param $short Boolean short circuit on first error
1819          *
1820          * @return Array list of errors
1821          */
1822         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1823                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1824                         # We /could/ use the protection level on the source page, but it's
1825                         # fairly ugly as we have to establish a precedence hierarchy for pages
1826                         # included by multiple cascade-protected pages. So just restrict
1827                         # it to people with 'protect' permission, as they could remove the
1828                         # protection anyway.
1829                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1830                         # Cascading protection depends on more than this page...
1831                         # Several cascading protected pages may include this page...
1832                         # Check each cascading level
1833                         # This is only for protection restrictions, not for all actions
1834                         if ( isset( $restrictions[$action] ) ) {
1835                                 foreach ( $restrictions[$action] as $right ) {
1836                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1837                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1838                                                 $pages = '';
1839                                                 foreach ( $cascadingSources as $page )
1840                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1841                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1842                                         }
1843                                 }
1844                         }
1845                 }
1846
1847                 return $errors;
1848         }
1849
1850         /**
1851          * Check action permissions not already checked in checkQuickPermissions
1852          *
1853          * @param $action String the action to check
1854          * @param $user User to check
1855          * @param $errors Array list of current errors
1856          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1857          * @param $short Boolean short circuit on first error
1858          *
1859          * @return Array list of errors
1860          */
1861         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1862                 global $wgDeleteRevisionsLimit, $wgLang;
1863
1864                 if ( $action == 'protect' ) {
1865                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1866                                 // If they can't edit, they shouldn't protect.
1867                                 $errors[] = array( 'protect-cantedit' );
1868                         }
1869                 } elseif ( $action == 'create' ) {
1870                         $title_protection = $this->getTitleProtection();
1871                         if( $title_protection ) {
1872                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1873                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1874                                 }
1875                                 if( $title_protection['pt_create_perm'] == '' ||
1876                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1877                                 {
1878                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1879                                 }
1880                         }
1881                 } elseif ( $action == 'move' ) {
1882                         // Check for immobile pages
1883                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1884                                 // Specific message for this case
1885                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1886                         } elseif ( !$this->isMovable() ) {
1887                                 // Less specific message for rarer cases
1888                                 $errors[] = array( 'immobile-source-page' );
1889                         }
1890                 } elseif ( $action == 'move-target' ) {
1891                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1892                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1893                         } elseif ( !$this->isMovable() ) {
1894                                 $errors[] = array( 'immobile-target-page' );
1895                         }
1896                 } elseif ( $action == 'delete' ) {
1897                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1898                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1899                         {
1900                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1901                         }
1902                 }
1903                 return $errors;
1904         }
1905
1906         /**
1907          * Check that the user isn't blocked from editting.
1908          *
1909          * @param $action String the action to check
1910          * @param $user User to check
1911          * @param $errors Array list of current errors
1912          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1913          * @param $short Boolean short circuit on first error
1914          *
1915          * @return Array list of errors
1916          */
1917         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1918                 // Account creation blocks handled at userlogin.
1919                 // Unblocking handled in SpecialUnblock
1920                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1921                         return $errors;
1922                 }
1923
1924                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1925
1926                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1927                         $errors[] = array( 'confirmedittext' );
1928                 }
1929
1930                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1931                         // Don't block the user from editing their own talk page unless they've been
1932                         // explicitly blocked from that too.
1933                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1934                         $block = $user->getBlock();
1935
1936                         // This is from OutputPage::blockedPage
1937                         // Copied at r23888 by werdna
1938
1939                         $id = $user->blockedBy();
1940                         $reason = $user->blockedFor();
1941                         if ( $reason == '' ) {
1942                                 $reason = wfMsg( 'blockednoreason' );
1943                         }
1944                         $ip = $user->getRequest()->getIP();
1945
1946                         if ( is_numeric( $id ) ) {
1947                                 $name = User::whoIs( $id );
1948                         } else {
1949                                 $name = $id;
1950                         }
1951
1952                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1953                         $blockid = $block->getId();
1954                         $blockExpiry = $block->getExpiry();
1955                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
1956                         if ( $blockExpiry == 'infinity' ) {
1957                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1958                         } else {
1959                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1960                         }
1961
1962                         $intended = strval( $block->getTarget() );
1963
1964                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1965                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1966                 }
1967
1968                 return $errors;
1969         }
1970
1971         /**
1972          * Check that the user is allowed to read this page.
1973          *
1974          * @param $action String the action to check
1975          * @param $user User to check
1976          * @param $errors Array list of current errors
1977          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1978          * @param $short Boolean short circuit on first error
1979          *
1980          * @return Array list of errors
1981          */
1982         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1983                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
1984                 static $useShortcut = null;
1985
1986                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1987                 if ( is_null( $useShortcut ) ) {
1988                         $useShortcut = true;
1989                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1990                                 # Not a public wiki, so no shortcut
1991                                 $useShortcut = false;
1992                         } elseif ( !empty( $wgRevokePermissions ) ) {
1993                                 /**
1994                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1995                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1996                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1997                                  * reading is allowed.
1998                                  */
1999                                 foreach ( $wgRevokePermissions as $perms ) {
2000                                         if ( !empty( $perms['read'] ) ) {
2001                                                 # We might be removing the read right from the user, so no shortcut
2002                                                 $useShortcut = false;
2003                                                 break;
2004                                         }
2005                                 }
2006                         }
2007                 }
2008
2009                 $whitelisted = false;
2010                 if ( $useShortcut ) {
2011                         # Shortcut for public wikis, allows skipping quite a bit of code
2012                         $whitelisted = true;
2013                 } elseif ( $user->isAllowed( 'read' ) ) {
2014                         # If the user is allowed to read pages, he is allowed to read all pages
2015                         $whitelisted = true;
2016                 } elseif ( $this->isSpecial( 'Userlogin' )
2017                         || $this->isSpecial( 'ChangePassword' )
2018                         || $this->isSpecial( 'PasswordReset' )
2019                 ) {
2020                         # Always grant access to the login page.
2021                         # Even anons need to be able to log in.
2022                         $whitelisted = true;
2023                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2024                         # Time to check the whitelist
2025                         # Only do these checks is there's something to check against
2026                         $name = $this->getPrefixedText();
2027                         $dbName = $this->getPrefixedDBKey();
2028
2029                         // Check for explicit whitelisting with and without underscores
2030                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2031                                 $whitelisted = true;
2032                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2033                                 # Old settings might have the title prefixed with
2034                                 # a colon for main-namespace pages
2035                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2036                                         $whitelisted = true;
2037                                 }
2038                         } elseif ( $this->isSpecialPage() ) {
2039                                 # If it's a special page, ditch the subpage bit and check again
2040                                 $name = $this->getDBkey();
2041                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2042                                 if ( $name !== false ) {
2043                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2044                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2045                                                 $whitelisted = true;
2046                                         }
2047                                 }
2048                         }
2049                 }
2050
2051                 if ( !$whitelisted ) {
2052                         # If the title is not whitelisted, give extensions a chance to do so...
2053                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2054                         if ( !$whitelisted ) {
2055                                 $errors[] = $this->missingPermissionError( $action, $short );
2056                         }
2057                 }
2058
2059                 return $errors;
2060         }
2061
2062         /**
2063          * Get a description array when the user doesn't have the right to perform
2064          * $action (i.e. when User::isAllowed() returns false)
2065          *
2066          * @param $action String the action to check
2067          * @param $short Boolean short circuit on first error
2068          * @return Array list of errors
2069          */
2070         private function missingPermissionError( $action, $short ) {
2071                 // We avoid expensive display logic for quickUserCan's and such
2072                 if ( $short ) {
2073                         return array( 'badaccess-group0' );
2074                 }
2075
2076                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2077                         User::getGroupsWithPermission( $action ) );
2078
2079                 if ( count( $groups ) ) {
2080                         global $wgLang;
2081                         return array(
2082                                 'badaccess-groups',
2083                                 $wgLang->commaList( $groups ),
2084                                 count( $groups )
2085                         );
2086                 } else {
2087                         return array( 'badaccess-group0' );
2088                 }
2089         }
2090
2091         /**
2092          * Can $user perform $action on this page? This is an internal function,
2093          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2094          * checks on wfReadOnly() and blocks)
2095          *
2096          * @param $action String action that permission needs to be checked for
2097          * @param $user User to check
2098          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2099          * @param $short Bool Set this to true to stop after the first permission error.
2100          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2101          */
2102         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2103                 wfProfileIn( __METHOD__ );
2104
2105                 # Read has special handling
2106                 if ( $action == 'read' ) {
2107                         $checks = array(
2108                                 'checkPermissionHooks',
2109                                 'checkReadPermissions',
2110                         );
2111                 } else {
2112                         $checks = array(
2113                                 'checkQuickPermissions',
2114                                 'checkPermissionHooks',
2115                                 'checkSpecialsAndNSPermissions',
2116                                 'checkCSSandJSPermissions',
2117                                 'checkPageRestrictions',
2118                                 'checkCascadingSourcesRestrictions',
2119                                 'checkActionPermissions',
2120                                 'checkUserBlock'
2121                         );
2122                 }
2123
2124                 $errors = array();
2125                 while( count( $checks ) > 0 &&
2126                                 !( $short && count( $errors ) > 0 ) ) {
2127                         $method = array_shift( $checks );
2128                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2129                 }
2130
2131                 wfProfileOut( __METHOD__ );
2132                 return $errors;
2133         }
2134
2135         /**
2136          * Protect css subpages of user pages: can $wgUser edit
2137          * this page?
2138          *
2139          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2140          * @return Bool
2141          */
2142         public function userCanEditCssSubpage() {
2143                 global $wgUser;
2144                 wfDeprecated( __METHOD__, '1.19' );
2145                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2146                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2147         }
2148
2149         /**
2150          * Protect js subpages of user pages: can $wgUser edit
2151          * this page?
2152          *
2153          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2154          * @return Bool
2155          */
2156         public function userCanEditJsSubpage() {
2157                 global $wgUser;
2158                 wfDeprecated( __METHOD__, '1.19' );
2159                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2160                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2161         }
2162
2163         /**
2164          * Get a filtered list of all restriction types supported by this wiki.
2165          * @param bool $exists True to get all restriction types that apply to
2166          * titles that do exist, False for all restriction types that apply to
2167          * titles that do not exist
2168          * @return array
2169          */
2170         public static function getFilteredRestrictionTypes( $exists = true ) {
2171                 global $wgRestrictionTypes;
2172                 $types = $wgRestrictionTypes;
2173                 if ( $exists ) {
2174                         # Remove the create restriction for existing titles
2175                         $types = array_diff( $types, array( 'create' ) );
2176                 } else {
2177                         # Only the create and upload restrictions apply to non-existing titles
2178                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2179                 }
2180                 return $types;
2181         }
2182
2183         /**
2184          * Returns restriction types for the current Title
2185          *
2186          * @return array applicable restriction types
2187          */
2188         public function getRestrictionTypes() {
2189                 if ( $this->isSpecialPage() ) {
2190                         return array();
2191                 }
2192
2193                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2194
2195                 if ( $this->getNamespace() != NS_FILE ) {
2196                         # Remove the upload restriction for non-file titles
2197                         $types = array_diff( $types, array( 'upload' ) );
2198                 }
2199
2200                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2201
2202                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2203                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2204
2205                 return $types;
2206         }
2207
2208         /**
2209          * Is this title subject to title protection?
2210          * Title protection is the one applied against creation of such title.
2211          *
2212          * @return Mixed An associative array representing any existent title
2213          *   protection, or false if there's none.
2214          */
2215         private function getTitleProtection() {
2216                 // Can't protect pages in special namespaces
2217                 if ( $this->getNamespace() < 0 ) {
2218                         return false;
2219                 }
2220
2221                 // Can't protect pages that exist.
2222                 if ( $this->exists() ) {
2223                         return false;
2224                 }
2225
2226                 if ( !isset( $this->mTitleProtection ) ) {
2227                         $dbr = wfGetDB( DB_SLAVE );
2228                         $res = $dbr->select( 'protected_titles', '*',
2229                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2230                                 __METHOD__ );
2231
2232                         // fetchRow returns false if there are no rows.
2233                         $this->mTitleProtection = $dbr->fetchRow( $res );
2234                 }
2235                 return $this->mTitleProtection;
2236         }
2237
2238         /**
2239          * Update the title protection status
2240          *
2241          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2242          * @param $create_perm String Permission required for creation
2243          * @param $reason String Reason for protection
2244          * @param $expiry String Expiry timestamp
2245          * @return boolean true
2246          */
2247         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2248                 wfDeprecated( __METHOD__, '1.19' );
2249
2250                 global $wgUser;
2251
2252                 $limit = array( 'create' => $create_perm );
2253                 $expiry = array( 'create' => $expiry );
2254
2255                 $page = WikiPage::factory( $this );
2256                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2257
2258                 return $status->isOK();
2259         }
2260
2261         /**
2262          * Remove any title protection due to page existing
2263          */
2264         public function deleteTitleProtection() {
2265                 $dbw = wfGetDB( DB_MASTER );
2266
2267                 $dbw->delete(
2268                         'protected_titles',
2269                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2270                         __METHOD__
2271                 );
2272                 $this->mTitleProtection = false;
2273         }
2274
2275         /**
2276          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2277          *
2278          * @param $action String Action to check (default: edit)
2279          * @return Bool
2280          */
2281         public function isSemiProtected( $action = 'edit' ) {
2282                 if ( $this->exists() ) {
2283                         $restrictions = $this->getRestrictions( $action );
2284                         if ( count( $restrictions ) > 0 ) {
2285                                 foreach ( $restrictions as $restriction ) {
2286                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2287                                                 return false;
2288                                         }
2289                                 }
2290                         } else {
2291                                 # Not protected
2292                                 return false;
2293                         }
2294                         return true;
2295                 } else {
2296                         # If it doesn't exist, it can't be protected
2297                         return false;
2298                 }
2299         }
2300
2301         /**
2302          * Does the title correspond to a protected article?
2303          *
2304          * @param $action String the action the page is protected from,
2305          * by default checks all actions.
2306          * @return Bool
2307          */
2308         public function isProtected( $action = '' ) {
2309                 global $wgRestrictionLevels;
2310
2311                 $restrictionTypes = $this->getRestrictionTypes();
2312
2313                 # Special pages have inherent protection
2314                 if( $this->isSpecialPage() ) {
2315                         return true;
2316                 }
2317
2318                 # Check regular protection levels
2319                 foreach ( $restrictionTypes as $type ) {
2320                         if ( $action == $type || $action == '' ) {
2321                                 $r = $this->getRestrictions( $type );
2322                                 foreach ( $wgRestrictionLevels as $level ) {
2323                                         if ( in_array( $level, $r ) && $level != '' ) {
2324                                                 return true;
2325                                         }
2326                                 }
2327                         }
2328                 }
2329
2330                 return false;
2331         }
2332
2333         /**
2334          * Determines if $user is unable to edit this page because it has been protected
2335          * by $wgNamespaceProtection.
2336          *
2337          * @param $user User object to check permissions
2338          * @return Bool
2339          */
2340         public function isNamespaceProtected( User $user ) {
2341                 global $wgNamespaceProtection;
2342
2343                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2344                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2345                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2346                                         return true;
2347                                 }
2348                         }
2349                 }
2350                 return false;
2351         }
2352
2353         /**
2354          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2355          *
2356          * @return Bool If the page is subject to cascading restrictions.
2357          */
2358         public function isCascadeProtected() {
2359                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2360                 return ( $sources > 0 );
2361         }
2362
2363         /**
2364          * Cascading protection: Get the source of any cascading restrictions on this page.
2365          *
2366          * @param $getPages Bool Whether or not to retrieve the actual pages
2367          *        that the restrictions have come from.
2368          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2369          *     have come, false for none, or true if such restrictions exist, but $getPages
2370          *     was not set.  The restriction array is an array of each type, each of which
2371          *     contains a array of unique groups.
2372          */
2373         public function getCascadeProtectionSources( $getPages = true ) {
2374                 global $wgContLang;
2375                 $pagerestrictions = array();
2376
2377                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2378                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2379                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2380                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2381                 }
2382
2383                 wfProfileIn( __METHOD__ );
2384
2385                 $dbr = wfGetDB( DB_SLAVE );
2386
2387                 if ( $this->getNamespace() == NS_FILE ) {
2388                         $tables = array( 'imagelinks', 'page_restrictions' );
2389                         $where_clauses = array(
2390                                 'il_to' => $this->getDBkey(),
2391                                 'il_from=pr_page',
2392                                 'pr_cascade' => 1
2393                         );
2394                 } else {
2395                         $tables = array( 'templatelinks', 'page_restrictions' );
2396                         $where_clauses = array(
2397                                 'tl_namespace' => $this->getNamespace(),
2398                                 'tl_title' => $this->getDBkey(),
2399                                 'tl_from=pr_page',
2400                                 'pr_cascade' => 1
2401                         );
2402                 }
2403
2404                 if ( $getPages ) {
2405                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2406                                                    'pr_expiry', 'pr_type', 'pr_level' );
2407                         $where_clauses[] = 'page_id=pr_page';
2408                         $tables[] = 'page';
2409                 } else {
2410                         $cols = array( 'pr_expiry' );
2411                 }
2412
2413                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2414
2415                 $sources = $getPages ? array() : false;
2416                 $now = wfTimestampNow();
2417                 $purgeExpired = false;
2418
2419                 foreach ( $res as $row ) {
2420                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2421                         if ( $expiry > $now ) {
2422                                 if ( $getPages ) {
2423                                         $page_id = $row->pr_page;
2424                                         $page_ns = $row->page_namespace;
2425                                         $page_title = $row->page_title;
2426                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2427                                         # Add groups needed for each restriction type if its not already there
2428                                         # Make sure this restriction type still exists
2429
2430                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2431                                                 $pagerestrictions[$row->pr_type] = array();
2432                                         }
2433
2434                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2435                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2436                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2437                                         }
2438                                 } else {
2439                                         $sources = true;
2440                                 }
2441                         } else {
2442                                 // Trigger lazy purge of expired restrictions from the db
2443                                 $purgeExpired = true;
2444                         }
2445                 }
2446                 if ( $purgeExpired ) {
2447                         Title::purgeExpiredRestrictions();
2448                 }
2449
2450                 if ( $getPages ) {
2451                         $this->mCascadeSources = $sources;
2452                         $this->mCascadingRestrictions = $pagerestrictions;
2453                 } else {
2454                         $this->mHasCascadingRestrictions = $sources;
2455                 }
2456
2457                 wfProfileOut( __METHOD__ );
2458                 return array( $sources, $pagerestrictions );
2459         }
2460
2461         /**
2462          * Accessor/initialisation for mRestrictions
2463          *
2464          * @param $action String action that permission needs to be checked for
2465          * @return Array of Strings the array of groups allowed to edit this article
2466          */
2467         public function getRestrictions( $action ) {
2468                 if ( !$this->mRestrictionsLoaded ) {
2469                         $this->loadRestrictions();
2470                 }
2471                 return isset( $this->mRestrictions[$action] )
2472                                 ? $this->mRestrictions[$action]
2473                                 : array();
2474         }
2475
2476         /**
2477          * Get the expiry time for the restriction against a given action
2478          *
2479          * @param $action
2480          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2481          *     or not protected at all, or false if the action is not recognised.
2482          */
2483         public function getRestrictionExpiry( $action ) {
2484                 if ( !$this->mRestrictionsLoaded ) {
2485                         $this->loadRestrictions();
2486                 }
2487                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2488         }
2489
2490         /**
2491          * Returns cascading restrictions for the current article
2492          *
2493          * @return Boolean
2494          */
2495         function areRestrictionsCascading() {
2496                 if ( !$this->mRestrictionsLoaded ) {
2497                         $this->loadRestrictions();
2498                 }
2499
2500                 return $this->mCascadeRestriction;
2501         }
2502
2503         /**
2504          * Loads a string into mRestrictions array
2505          *
2506          * @param $res Resource restrictions as an SQL result.
2507          * @param $oldFashionedRestrictions String comma-separated list of page
2508          *        restrictions from page table (pre 1.10)
2509          */
2510         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2511                 $rows = array();
2512
2513                 foreach ( $res as $row ) {
2514                         $rows[] = $row;
2515                 }
2516
2517                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2518         }
2519
2520         /**
2521          * Compiles list of active page restrictions from both page table (pre 1.10)
2522          * and page_restrictions table for this existing page.
2523          * Public for usage by LiquidThreads.
2524          *
2525          * @param $rows array of db result objects
2526          * @param $oldFashionedRestrictions string comma-separated list of page
2527          *        restrictions from page table (pre 1.10)
2528          */
2529         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2530                 global $wgContLang;
2531                 $dbr = wfGetDB( DB_SLAVE );
2532
2533                 $restrictionTypes = $this->getRestrictionTypes();
2534
2535                 foreach ( $restrictionTypes as $type ) {
2536                         $this->mRestrictions[$type] = array();
2537                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2538                 }
2539
2540                 $this->mCascadeRestriction = false;
2541
2542                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2543
2544                 if ( $oldFashionedRestrictions === null ) {
2545                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2546                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2547                 }
2548
2549                 if ( $oldFashionedRestrictions != '' ) {
2550
2551                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2552                                 $temp = explode( '=', trim( $restrict ) );
2553                                 if ( count( $temp ) == 1 ) {
2554                                         // old old format should be treated as edit/move restriction
2555                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2556                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2557                                 } else {
2558                                         $restriction = trim( $temp[1] );
2559                                         if( $restriction != '' ) { //some old entries are empty
2560                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2561                                         }
2562                                 }
2563                         }
2564
2565                         $this->mOldRestrictions = true;
2566
2567                 }
2568
2569                 if ( count( $rows ) ) {
2570                         # Current system - load second to make them override.
2571                         $now = wfTimestampNow();
2572                         $purgeExpired = false;
2573
2574                         # Cycle through all the restrictions.
2575                         foreach ( $rows as $row ) {
2576
2577                                 // Don't take care of restrictions types that aren't allowed
2578                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2579                                         continue;
2580
2581                                 // This code should be refactored, now that it's being used more generally,
2582                                 // But I don't really see any harm in leaving it in Block for now -werdna
2583                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2584
2585                                 // Only apply the restrictions if they haven't expired!
2586                                 if ( !$expiry || $expiry > $now ) {
2587                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2588                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2589
2590                                         $this->mCascadeRestriction |= $row->pr_cascade;
2591                                 } else {
2592                                         // Trigger a lazy purge of expired restrictions
2593                                         $purgeExpired = true;
2594                                 }
2595                         }
2596
2597                         if ( $purgeExpired ) {
2598                                 Title::purgeExpiredRestrictions();
2599                         }
2600                 }
2601
2602                 $this->mRestrictionsLoaded = true;
2603         }
2604
2605         /**
2606          * Load restrictions from the page_restrictions table
2607          *
2608          * @param $oldFashionedRestrictions String comma-separated list of page
2609          *        restrictions from page table (pre 1.10)
2610          */
2611         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2612                 global $wgContLang;
2613                 if ( !$this->mRestrictionsLoaded ) {
2614                         if ( $this->exists() ) {
2615                                 $dbr = wfGetDB( DB_SLAVE );
2616
2617                                 $res = $dbr->select(
2618                                         'page_restrictions',
2619                                         '*',
2620                                         array( 'pr_page' => $this->getArticleID() ),
2621                                         __METHOD__
2622                                 );
2623
2624                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2625                         } else {
2626                                 $title_protection = $this->getTitleProtection();
2627
2628                                 if ( $title_protection ) {
2629                                         $now = wfTimestampNow();
2630                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2631
2632                                         if ( !$expiry || $expiry > $now ) {
2633                                                 // Apply the restrictions
2634                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2635                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2636                                         } else { // Get rid of the old restrictions
2637                                                 Title::purgeExpiredRestrictions();
2638                                                 $this->mTitleProtection = false;
2639                                         }
2640                                 } else {
2641                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2642                                 }
2643                                 $this->mRestrictionsLoaded = true;
2644                         }
2645                 }
2646         }
2647
2648         /**
2649          * Flush the protection cache in this object and force reload from the database.
2650          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2651          */
2652         public function flushRestrictions() {
2653                 $this->mRestrictionsLoaded = false;
2654                 $this->mTitleProtection = null;
2655         }
2656
2657         /**
2658          * Purge expired restrictions from the page_restrictions table
2659          */
2660         static function purgeExpiredRestrictions() {
2661                 $dbw = wfGetDB( DB_MASTER );
2662                 $dbw->delete(
2663                         'page_restrictions',
2664                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2665                         __METHOD__
2666                 );
2667
2668                 $dbw->delete(
2669                         'protected_titles',
2670                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2671                         __METHOD__
2672                 );
2673         }
2674
2675         /**
2676          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2677          *
2678          * @return Bool
2679          */
2680         public function hasSubpages() {
2681                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2682                         # Duh
2683                         return false;
2684                 }
2685
2686                 # We dynamically add a member variable for the purpose of this method
2687                 # alone to cache the result.  There's no point in having it hanging
2688                 # around uninitialized in every Title object; therefore we only add it
2689                 # if needed and don't declare it statically.
2690                 if ( isset( $this->mHasSubpages ) ) {
2691                         return $this->mHasSubpages;
2692                 }
2693
2694                 $subpages = $this->getSubpages( 1 );
2695                 if ( $subpages instanceof TitleArray ) {
2696                         return $this->mHasSubpages = (bool)$subpages->count();
2697                 }
2698                 return $this->mHasSubpages = false;
2699         }
2700
2701         /**
2702          * Get all subpages of this page.
2703          *
2704          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2705          * @return mixed TitleArray, or empty array if this page's namespace
2706          *  doesn't allow subpages
2707          */
2708         public function getSubpages( $limit = -1 ) {
2709                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2710                         return array();
2711                 }
2712
2713                 $dbr = wfGetDB( DB_SLAVE );
2714                 $conds['page_namespace'] = $this->getNamespace();
2715                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2716                 $options = array();
2717                 if ( $limit > -1 ) {
2718                         $options['LIMIT'] = $limit;
2719                 }
2720                 return $this->mSubpages = TitleArray::newFromResult(
2721                         $dbr->select( 'page',
2722                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2723                                 $conds,
2724                                 __METHOD__,
2725                                 $options
2726                         )
2727                 );
2728         }
2729
2730         /**
2731          * Is there a version of this page in the deletion archive?
2732          *
2733          * @return Int the number of archived revisions
2734          */
2735         public function isDeleted() {
2736                 if ( $this->getNamespace() < 0 ) {
2737                         $n = 0;
2738                 } else {
2739                         $dbr = wfGetDB( DB_SLAVE );
2740
2741                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2742                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2743                                 __METHOD__
2744                         );
2745                         if ( $this->getNamespace() == NS_FILE ) {
2746                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2747                                         array( 'fa_name' => $this->getDBkey() ),
2748                                         __METHOD__
2749                                 );
2750                         }
2751                 }
2752                 return (int)$n;
2753         }
2754
2755         /**
2756          * Is there a version of this page in the deletion archive?
2757          *
2758          * @return Boolean
2759          */
2760         public function isDeletedQuick() {
2761                 if ( $this->getNamespace() < 0 ) {
2762                         return false;
2763                 }
2764                 $dbr = wfGetDB( DB_SLAVE );
2765                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2766                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2767                         __METHOD__
2768                 );
2769                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2770                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2771                                 array( 'fa_name' => $this->getDBkey() ),
2772                                 __METHOD__
2773                         );
2774                 }
2775                 return $deleted;
2776         }
2777
2778         /**
2779          * Get the article ID for this Title from the link cache,
2780          * adding it if necessary
2781          *
2782          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2783          *  for update
2784          * @return Int the ID
2785          */
2786         public function getArticleID( $flags = 0 ) {
2787                 if ( $this->getNamespace() < 0 ) {
2788                         return $this->mArticleID = 0;
2789                 }
2790                 $linkCache = LinkCache::singleton();
2791                 if ( $flags & self::GAID_FOR_UPDATE ) {
2792                         $oldUpdate = $linkCache->forUpdate( true );
2793                         $linkCache->clearLink( $this );
2794                         $this->mArticleID = $linkCache->addLinkObj( $this );
2795                         $linkCache->forUpdate( $oldUpdate );
2796                 } else {
2797                         if ( -1 == $this->mArticleID ) {
2798                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2799                         }
2800                 }
2801                 return $this->mArticleID;
2802         }
2803
2804         /**
2805          * Is this an article that is a redirect page?
2806          * Uses link cache, adding it if necessary
2807          *
2808          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2809          * @return Bool
2810          */
2811         public function isRedirect( $flags = 0 ) {
2812                 if ( !is_null( $this->mRedirect ) ) {
2813                         return $this->mRedirect;
2814                 }
2815                 # Calling getArticleID() loads the field from cache as needed
2816                 if ( !$this->getArticleID( $flags ) ) {
2817                         return $this->mRedirect = false;
2818                 }
2819                 $linkCache = LinkCache::singleton();
2820                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2821
2822                 return $this->mRedirect;
2823         }
2824
2825         /**
2826          * What is the length of this page?
2827          * Uses link cache, adding it if necessary
2828          *
2829          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2830          * @return Int
2831          */
2832         public function getLength( $flags = 0 ) {
2833                 if ( $this->mLength != -1 ) {
2834                         return $this->mLength;
2835                 }
2836                 # Calling getArticleID() loads the field from cache as needed
2837                 if ( !$this->getArticleID( $flags ) ) {
2838                         return $this->mLength = 0;
2839                 }
2840                 $linkCache = LinkCache::singleton();
2841                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2842
2843                 return $this->mLength;
2844         }
2845
2846         /**
2847          * What is the page_latest field for this page?
2848          *
2849          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2850          * @return Int or 0 if the page doesn't exist
2851          */
2852         public function getLatestRevID( $flags = 0 ) {
2853                 if ( $this->mLatestID !== false ) {
2854                         return intval( $this->mLatestID );
2855                 }
2856                 # Calling getArticleID() loads the field from cache as needed
2857                 if ( !$this->getArticleID( $flags ) ) {
2858                         return $this->mLatestID = 0;
2859                 }
2860                 $linkCache = LinkCache::singleton();
2861                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2862
2863                 return $this->mLatestID;
2864         }
2865
2866         /**
2867          * This clears some fields in this object, and clears any associated
2868          * keys in the "bad links" section of the link cache.
2869          *
2870          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2871          * loading of the new page_id. It's also called from
2872          * WikiPage::doDeleteArticle()
2873          *
2874          * @param $newid Int the new Article ID
2875          */
2876         public function resetArticleID( $newid ) {
2877                 $linkCache = LinkCache::singleton();
2878                 $linkCache->clearLink( $this );
2879
2880                 if ( $newid === false ) {
2881                         $this->mArticleID = -1;
2882                 } else {
2883                         $this->mArticleID = intval( $newid );
2884                 }
2885                 $this->mRestrictionsLoaded = false;
2886                 $this->mRestrictions = array();
2887                 $this->mRedirect = null;
2888                 $this->mLength = -1;
2889                 $this->mLatestID = false;
2890                 $this->mEstimateRevisions = null;
2891         }
2892
2893         /**
2894          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2895          *
2896          * @param $text String containing title to capitalize
2897          * @param $ns int namespace index, defaults to NS_MAIN
2898          * @return String containing capitalized title
2899          */
2900         public static function capitalize( $text, $ns = NS_MAIN ) {
2901                 global $wgContLang;
2902
2903                 if ( MWNamespace::isCapitalized( $ns ) ) {
2904                         return $wgContLang->ucfirst( $text );
2905                 } else {
2906                         return $text;
2907                 }
2908         }
2909
2910         /**
2911          * Secure and split - main initialisation function for this object
2912          *
2913          * Assumes that mDbkeyform has been set, and is urldecoded
2914          * and uses underscores, but not otherwise munged.  This function
2915          * removes illegal characters, splits off the interwiki and
2916          * namespace prefixes, sets the other forms, and canonicalizes
2917          * everything.
2918          *
2919          * @return Bool true on success
2920          */
2921         private function secureAndSplit() {
2922                 global $wgContLang, $wgLocalInterwiki;
2923
2924                 # Initialisation
2925                 $this->mInterwiki = $this->mFragment = '';
2926                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2927
2928                 $dbkey = $this->mDbkeyform;
2929
2930                 # Strip Unicode bidi override characters.
2931                 # Sometimes they slip into cut-n-pasted page titles, where the
2932                 # override chars get included in list displays.
2933                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2934
2935                 # Clean up whitespace
2936                 # Note: use of the /u option on preg_replace here will cause
2937                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2938                 # conveniently disabling them.
2939                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2940                 $dbkey = trim( $dbkey, '_' );
2941
2942                 if ( $dbkey == '' ) {
2943                         return false;
2944                 }
2945
2946                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2947                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2948                         return false;
2949                 }
2950
2951                 $this->mDbkeyform = $dbkey;
2952
2953                 # Initial colon indicates main namespace rather than specified default
2954                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2955                 if ( ':' == $dbkey[0] ) {
2956                         $this->mNamespace = NS_MAIN;
2957                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2958                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2959                 }
2960
2961                 # Namespace or interwiki prefix
2962                 $firstPass = true;
2963                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2964                 do {
2965                         $m = array();
2966                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2967                                 $p = $m[1];
2968                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2969                                         # Ordinary namespace
2970                                         $dbkey = $m[2];
2971                                         $this->mNamespace = $ns;
2972                                         # For Talk:X pages, check if X has a "namespace" prefix
2973                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2974                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2975                                                         # Disallow Talk:File:x type titles...
2976                                                         return false;
2977                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2978                                                         # Disallow Talk:Interwiki:x type titles...
2979                                                         return false;
2980                                                 }
2981                                         }
2982                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2983                                         if ( !$firstPass ) {
2984                                                 # Can't make a local interwiki link to an interwiki link.
2985                                                 # That's just crazy!
2986                                                 return false;
2987                                         }
2988
2989                                         # Interwiki link
2990                                         $dbkey = $m[2];
2991                                         $this->mInterwiki = $wgContLang->lc( $p );
2992
2993                                         # Redundant interwiki prefix to the local wiki
2994                                         if ( $wgLocalInterwiki !== false
2995                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2996                                         {
2997                                                 if ( $dbkey == '' ) {
2998                                                         # Can't have an empty self-link
2999                                                         return false;
3000                                                 }
3001                                                 $this->mInterwiki = '';
3002                                                 $firstPass = false;
3003                                                 # Do another namespace split...
3004                                                 continue;
3005                                         }
3006
3007                                         # If there's an initial colon after the interwiki, that also
3008                                         # resets the default namespace
3009                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3010                                                 $this->mNamespace = NS_MAIN;
3011                                                 $dbkey = substr( $dbkey, 1 );
3012                                         }
3013                                 }
3014                                 # If there's no recognized interwiki or namespace,
3015                                 # then let the colon expression be part of the title.
3016                         }
3017                         break;
3018                 } while ( true );
3019
3020                 # We already know that some pages won't be in the database!
3021                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3022                         $this->mArticleID = 0;
3023                 }
3024                 $fragment = strstr( $dbkey, '#' );
3025                 if ( false !== $fragment ) {
3026                         $this->setFragment( $fragment );
3027                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3028                         # remove whitespace again: prevents "Foo_bar_#"
3029                         # becoming "Foo_bar_"
3030                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3031                 }
3032
3033                 # Reject illegal characters.
3034                 $rxTc = self::getTitleInvalidRegex();
3035                 if ( preg_match( $rxTc, $dbkey ) ) {
3036                         return false;
3037                 }
3038
3039                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3040                 # reachable due to the way web browsers deal with 'relative' URLs.
3041                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3042                 if ( strpos( $dbkey, '.' ) !== false &&
3043                          ( $dbkey === '.' || $dbkey === '..' ||
3044                            strpos( $dbkey, './' ) === 0  ||
3045                            strpos( $dbkey, '../' ) === 0 ||
3046                            strpos( $dbkey, '/./' ) !== false ||
3047                            strpos( $dbkey, '/../' ) !== false  ||
3048                            substr( $dbkey, -2 ) == '/.' ||
3049                            substr( $dbkey, -3 ) == '/..' ) )
3050                 {
3051                         return false;
3052                 }
3053
3054                 # Magic tilde sequences? Nu-uh!
3055                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3056                         return false;
3057                 }
3058
3059                 # Limit the size of titles to 255 bytes. This is typically the size of the
3060                 # underlying database field. We make an exception for special pages, which
3061                 # don't need to be stored in the database, and may edge over 255 bytes due
3062                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3063                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3064                   strlen( $dbkey ) > 512 )
3065                 {
3066                         return false;
3067                 }
3068
3069                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3070                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3071                 # other site might be case-sensitive.
3072                 $this->mUserCaseDBKey = $dbkey;
3073                 if ( $this->mInterwiki == '' ) {
3074                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3075                 }
3076
3077                 # Can't make a link to a namespace alone... "empty" local links can only be
3078                 # self-links with a fragment identifier.
3079                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3080                         return false;
3081                 }
3082
3083                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3084                 // IP names are not allowed for accounts, and can only be referring to
3085                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3086                 // there are numerous ways to present the same IP. Having sp:contribs scan
3087                 // them all is silly and having some show the edits and others not is
3088                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3089                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3090                         ? IP::sanitizeIP( $dbkey )
3091                         : $dbkey;
3092
3093                 // Any remaining initial :s are illegal.
3094                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3095                         return false;
3096                 }
3097
3098                 # Fill fields
3099                 $this->mDbkeyform = $dbkey;
3100                 $this->mUrlform = wfUrlencode( $dbkey );
3101
3102                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3103
3104                 return true;
3105         }
3106
3107         /**
3108          * Get an array of Title objects linking to this Title
3109          * Also stores the IDs in the link cache.
3110          *
3111          * WARNING: do not use this function on arbitrary user-supplied titles!
3112          * On heavily-used templates it will max out the memory.
3113          *
3114          * @param $options Array: may be FOR UPDATE
3115          * @param $table String: table name
3116          * @param $prefix String: fields prefix
3117          * @return Array of Title objects linking here
3118          */
3119         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3120                 if ( count( $options ) > 0 ) {
3121                         $db = wfGetDB( DB_MASTER );
3122                 } else {
3123                         $db = wfGetDB( DB_SLAVE );
3124                 }
3125
3126                 $res = $db->select(
3127                         array( 'page', $table ),
3128                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3129                         array(
3130                                 "{$prefix}_from=page_id",
3131                                 "{$prefix}_namespace" => $this->getNamespace(),
3132                                 "{$prefix}_title"     => $this->getDBkey() ),
3133                         __METHOD__,
3134                         $options
3135                 );
3136
3137                 $retVal = array();
3138                 if ( $res->numRows() ) {
3139                         $linkCache = LinkCache::singleton();
3140                         foreach ( $res as $row ) {
3141                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3142                                 if ( $titleObj ) {
3143                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3144                                         $retVal[] = $titleObj;
3145                                 }
3146                         }
3147                 }
3148                 return $retVal;
3149         }
3150
3151         /**
3152          * Get an array of Title objects using this Title as a template
3153          * Also stores the IDs in the link cache.
3154          *
3155          * WARNING: do not use this function on arbitrary user-supplied titles!
3156          * On heavily-used templates it will max out the memory.
3157          *
3158          * @param $options Array: may be FOR UPDATE
3159          * @return Array of Title the Title objects linking here
3160          */
3161         public function getTemplateLinksTo( $options = array() ) {
3162                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3163         }
3164
3165         /**
3166          * Get an array of Title objects linked from this Title
3167          * Also stores the IDs in the link cache.
3168          *
3169          * WARNING: do not use this function on arbitrary user-supplied titles!
3170          * On heavily-used templates it will max out the memory.
3171          *
3172          * @param $options Array: may be FOR UPDATE
3173          * @param $table String: table name
3174          * @param $prefix String: fields prefix
3175          * @return Array of Title objects linking here
3176          */
3177         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3178                 $id = $this->getArticleID();
3179
3180                 # If the page doesn't exist; there can't be any link from this page
3181                 if ( !$id ) {
3182                         return array();
3183                 }
3184
3185                 if ( count( $options ) > 0 ) {
3186                         $db = wfGetDB( DB_MASTER );
3187                 } else {
3188                         $db = wfGetDB( DB_SLAVE );
3189                 }
3190
3191                 $namespaceFiled = "{$prefix}_namespace";
3192                 $titleField = "{$prefix}_title";
3193
3194                 $res = $db->select(
3195                         array( $table, 'page' ),
3196                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3197                         array( "{$prefix}_from" => $id ),
3198                         __METHOD__,
3199                         $options,
3200                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3201                 );
3202
3203                 $retVal = array();
3204                 if ( $res->numRows() ) {
3205                         $linkCache = LinkCache::singleton();
3206                         foreach ( $res as $row ) {
3207                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3208                                 if ( $titleObj ) {
3209                                         if ( $row->page_id ) {
3210                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3211                                         } else {
3212                                                 $linkCache->addBadLinkObj( $titleObj );
3213                                         }
3214                                         $retVal[] = $titleObj;
3215                                 }
3216                         }
3217                 }
3218                 return $retVal;
3219         }
3220
3221         /**
3222          * Get an array of Title objects used on this Title as a template
3223          * Also stores the IDs in the link cache.
3224          *
3225          * WARNING: do not use this function on arbitrary user-supplied titles!
3226          * On heavily-used templates it will max out the memory.
3227          *
3228          * @param $options Array: may be FOR UPDATE
3229          * @return Array of Title the Title objects used here
3230          */
3231         public function getTemplateLinksFrom( $options = array() ) {
3232                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3233         }
3234
3235         /**
3236          * Get an array of Title objects referring to non-existent articles linked from this page
3237          *
3238          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3239          * @return Array of Title the Title objects
3240          */
3241         public function getBrokenLinksFrom() {
3242                 if ( $this->getArticleID() == 0 ) {
3243                         # All links from article ID 0 are false positives
3244                         return array();
3245                 }
3246
3247                 $dbr = wfGetDB( DB_SLAVE );
3248                 $res = $dbr->select(
3249                         array( 'page', 'pagelinks' ),
3250                         array( 'pl_namespace', 'pl_title' ),
3251                         array(
3252                                 'pl_from' => $this->getArticleID(),
3253                                 'page_namespace IS NULL'
3254                         ),
3255                         __METHOD__, array(),
3256                         array(
3257                                 'page' => array(
3258                                         'LEFT JOIN',
3259                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3260                                 )
3261                         )
3262                 );
3263
3264                 $retVal = array();
3265                 foreach ( $res as $row ) {
3266                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3267                 }
3268                 return $retVal;
3269         }
3270
3271
3272         /**
3273          * Get a list of URLs to purge from the Squid cache when this
3274          * page changes
3275          *
3276          * @return Array of String the URLs
3277          */
3278         public function getSquidURLs() {
3279                 global $wgContLang;
3280
3281                 $urls = array(
3282                         $this->getInternalURL(),
3283                         $this->getInternalURL( 'action=history' )
3284                 );
3285
3286                 // purge variant urls as well
3287                 if ( $wgContLang->hasVariants() ) {
3288                         $variants = $wgContLang->getVariants();
3289                         foreach ( $variants as $vCode ) {
3290                                 $urls[] = $this->getInternalURL( '', $vCode );
3291                         }
3292                 }
3293
3294                 return $urls;
3295         }
3296
3297         /**
3298          * Purge all applicable Squid URLs
3299          */
3300         public function purgeSquid() {
3301                 global $wgUseSquid;
3302                 if ( $wgUseSquid ) {
3303                         $urls = $this->getSquidURLs();
3304                         $u = new SquidUpdate( $urls );
3305                         $u->doUpdate();
3306                 }
3307         }
3308
3309         /**
3310          * Move this page without authentication
3311          *
3312          * @param $nt Title the new page Title
3313          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3314          */
3315         public function moveNoAuth( &$nt ) {
3316                 return $this->moveTo( $nt, false );
3317         }
3318
3319         /**
3320          * Check whether a given move operation would be valid.
3321          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3322          *
3323          * @param $nt Title the new title
3324          * @param $auth Bool indicates whether $wgUser's permissions
3325          *  should be checked
3326          * @param $reason String is the log summary of the move, used for spam checking
3327          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3328          */
3329         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3330                 global $wgUser;
3331
3332                 $errors = array();
3333                 if ( !$nt ) {
3334                         // Normally we'd add this to $errors, but we'll get
3335                         // lots of syntax errors if $nt is not an object
3336                         return array( array( 'badtitletext' ) );
3337                 }
3338                 if ( $this->equals( $nt ) ) {
3339                         $errors[] = array( 'selfmove' );
3340                 }
3341                 if ( !$this->isMovable() ) {
3342                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3343                 }
3344                 if ( $nt->getInterwiki() != '' ) {
3345                         $errors[] = array( 'immobile-target-namespace-iw' );
3346                 }
3347                 if ( !$nt->isMovable() ) {
3348                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3349                 }
3350
3351                 $oldid = $this->getArticleID();
3352                 $newid = $nt->getArticleID();
3353
3354                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3355                         $errors[] = array( 'articleexists' );
3356                 }
3357                 if ( ( $this->getDBkey() == '' ) ||
3358                          ( !$oldid ) ||
3359                          ( $nt->getDBkey() == '' ) ) {
3360                         $errors[] = array( 'badarticleerror' );
3361                 }
3362
3363                 // Image-specific checks
3364                 if ( $this->getNamespace() == NS_FILE ) {
3365                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3366                 }
3367
3368                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3369                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3370                 }
3371
3372                 if ( $auth ) {
3373                         $errors = wfMergeErrorArrays( $errors,
3374                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3375                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3376                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3377                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3378                 }
3379
3380                 $match = EditPage::matchSummarySpamRegex( $reason );
3381                 if ( $match !== false ) {
3382                         // This is kind of lame, won't display nice
3383                         $errors[] = array( 'spamprotectiontext' );
3384                 }
3385
3386                 $err = null;
3387                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3388                         $errors[] = array( 'hookaborted', $err );
3389                 }
3390
3391                 # The move is allowed only if (1) the target doesn't exist, or
3392                 # (2) the target is a redirect to the source, and has no history
3393                 # (so we can undo bad moves right after they're done).
3394
3395                 if ( 0 != $newid ) { # Target exists; check for validity
3396                         if ( !$this->isValidMoveTarget( $nt ) ) {
3397                                 $errors[] = array( 'articleexists' );
3398                         }
3399                 } else {
3400                         $tp = $nt->getTitleProtection();
3401                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3402                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3403                                 $errors[] = array( 'cantmove-titleprotected' );
3404                         }
3405                 }
3406                 if ( empty( $errors ) ) {
3407                         return true;
3408                 }
3409                 return $errors;
3410         }
3411
3412         /**
3413          * Check if the requested move target is a valid file move target
3414          * @param Title $nt Target title
3415          * @return array List of errors
3416          */
3417         protected function validateFileMoveOperation( $nt ) {
3418                 global $wgUser;
3419
3420                 $errors = array();
3421
3422                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3423
3424                 $file = wfLocalFile( $this );
3425                 if ( $file->exists() ) {
3426                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3427                                 $errors[] = array( 'imageinvalidfilename' );
3428                         }
3429                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3430                                 $errors[] = array( 'imagetypemismatch' );
3431                         }
3432                 }
3433
3434                 if ( $nt->getNamespace() != NS_FILE ) {
3435                         $errors[] = array( 'imagenocrossnamespace' );
3436                         // From here we want to do checks on a file object, so if we can't
3437                         // create one, we must return.
3438                         return $errors;
3439                 }
3440
3441                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3442
3443                 $destFile = wfLocalFile( $nt );
3444                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3445                         $errors[] = array( 'file-exists-sharedrepo' );
3446                 }
3447
3448                 return $errors;
3449         }
3450
3451         /**
3452          * Move a title to a new location
3453          *
3454          * @param $nt Title the new title
3455          * @param $auth Bool indicates whether $wgUser's permissions
3456          *  should be checked
3457          * @param $reason String the reason for the move
3458          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3459          *  Ignored if the user doesn't have the suppressredirect right.
3460          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3461          */
3462         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3463                 global $wgUser;
3464                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3465                 if ( is_array( $err ) ) {
3466                         // Auto-block user's IP if the account was "hard" blocked
3467                         $wgUser->spreadAnyEditBlock();
3468                         return $err;
3469                 }
3470
3471                 // If it is a file, move it first.
3472                 // It is done before all other moving stuff is done because it's hard to revert.
3473                 $dbw = wfGetDB( DB_MASTER );
3474                 if ( $this->getNamespace() == NS_FILE ) {
3475                         $file = wfLocalFile( $this );
3476                         if ( $file->exists() ) {
3477                                 $status = $file->move( $nt );
3478                                 if ( !$status->isOk() ) {
3479                                         return $status->getErrorsArray();
3480                                 }
3481                         }
3482                         // Clear RepoGroup process cache
3483                         RepoGroup::singleton()->clearCache( $this );
3484                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3485                 }
3486
3487                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3488                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3489                 $protected = $this->isProtected();
3490
3491                 // Do the actual move
3492                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3493                 if ( is_array( $err ) ) {
3494                         # @todo FIXME: What about the File we have already moved?
3495                         $dbw->rollback( __METHOD__ );
3496                         return $err;
3497                 }
3498
3499                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3500                 // cl_timestamp, which may disturb time-based lists on some sites.
3501                 $prefixes = $dbw->select(
3502                         'categorylinks',
3503                         array( 'cl_sortkey_prefix', 'cl_to' ),
3504                         array( 'cl_from' => $pageid ),
3505                         __METHOD__
3506                 );
3507                 foreach ( $prefixes as $prefixRow ) {
3508                         $prefix = $prefixRow->cl_sortkey_prefix;
3509                         $catTo = $prefixRow->cl_to;
3510                         $dbw->update( 'categorylinks',
3511                                 array(
3512                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3513                                                 $nt->getCategorySortkey( $prefix ) ),
3514                                         'cl_timestamp=cl_timestamp' ),
3515                                 array(
3516                                         'cl_from' => $pageid,
3517                                         'cl_to' => $catTo ),
3518                                 __METHOD__
3519                         );
3520                 }
3521
3522                 $redirid = $this->getArticleID();
3523
3524                 if ( $protected ) {
3525                         # Protect the redirect title as the title used to be...
3526                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3527                                 array(
3528                                         'pr_page'    => $redirid,
3529                                         'pr_type'    => 'pr_type',
3530                                         'pr_level'   => 'pr_level',
3531                                         'pr_cascade' => 'pr_cascade',
3532                                         'pr_user'    => 'pr_user',
3533                                         'pr_expiry'  => 'pr_expiry'
3534                                 ),
3535                                 array( 'pr_page' => $pageid ),
3536                                 __METHOD__,
3537                                 array( 'IGNORE' )
3538                         );
3539                         # Update the protection log
3540                         $log = new LogPage( 'protect' );
3541                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3542                         if ( $reason ) {
3543                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3544                         }
3545                         // @todo FIXME: $params?
3546                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3547                 }
3548
3549                 # Update watchlists
3550                 $oldnamespace = $this->getNamespace() & ~1;
3551                 $newnamespace = $nt->getNamespace() & ~1;
3552                 $oldtitle = $this->getDBkey();
3553                 $newtitle = $nt->getDBkey();
3554
3555                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3556                         WatchedItem::duplicateEntries( $this, $nt );
3557                 }
3558
3559                 $dbw->commit( __METHOD__ );
3560
3561                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3562                 return true;
3563         }
3564
3565         /**
3566          * Move page to a title which is either a redirect to the
3567          * source page or nonexistent
3568          *
3569          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3570          * @param $reason String The reason for the move
3571          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3572          *   if the user doesn't have the suppressredirect right
3573          */
3574         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3575                 global $wgUser, $wgContLang;
3576
3577                 if ( $nt->exists() ) {
3578                         $moveOverRedirect = true;
3579                         $logType = 'move_redir';
3580                 } else {
3581                         $moveOverRedirect = false;
3582                         $logType = 'move';
3583                 }
3584
3585                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3586
3587                 $logEntry = new ManualLogEntry( 'move', $logType );
3588                 $logEntry->setPerformer( $wgUser );
3589                 $logEntry->setTarget( $this );
3590                 $logEntry->setComment( $reason );
3591                 $logEntry->setParameters( array(
3592                         '4::target' => $nt->getPrefixedText(),
3593                         '5::noredir' => $redirectSuppressed ? '1': '0',
3594                 ) );
3595
3596                 $formatter = LogFormatter::newFromEntry( $logEntry );
3597                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3598                 $comment = $formatter->getPlainActionText();
3599                 if ( $reason ) {
3600                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3601                 }
3602                 # Truncate for whole multibyte characters.
3603                 $comment = $wgContLang->truncate( $comment, 255 );
3604
3605                 $oldid = $this->getArticleID();
3606
3607                 $dbw = wfGetDB( DB_MASTER );
3608
3609                 $newpage = WikiPage::factory( $nt );
3610
3611                 if ( $moveOverRedirect ) {
3612                         $newid = $nt->getArticleID();
3613
3614                         # Delete the old redirect. We don't save it to history since
3615                         # by definition if we've got here it's rather uninteresting.
3616                         # We have to remove it so that the next step doesn't trigger
3617                         # a conflict on the unique namespace+title index...
3618                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3619
3620                         $newpage->doDeleteUpdates( $newid );
3621                 }
3622
3623                 # Save a null revision in the page's history notifying of the move
3624                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3625                 if ( !is_object( $nullRevision ) ) {
3626                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3627                 }
3628                 $nullRevId = $nullRevision->insertOn( $dbw );
3629
3630                 # Change the name of the target page:
3631                 $dbw->update( 'page',
3632                         /* SET */ array(
3633                                 'page_namespace' => $nt->getNamespace(),
3634                                 'page_title'     => $nt->getDBkey(),
3635                         ),
3636                         /* WHERE */ array( 'page_id' => $oldid ),
3637                         __METHOD__
3638                 );
3639
3640                 $this->resetArticleID( 0 );
3641                 $nt->resetArticleID( $oldid );
3642
3643                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3644
3645                 wfRunHooks( 'NewRevisionFromEditComplete',
3646                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3647
3648                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3649
3650                 if ( !$moveOverRedirect ) {
3651                         WikiPage::onArticleCreate( $nt );
3652                 }
3653
3654                 # Recreate the redirect, this time in the other direction.
3655                 if ( $redirectSuppressed ) {
3656                         WikiPage::onArticleDelete( $this );
3657                 } else {
3658                         $mwRedir = MagicWord::get( 'redirect' );
3659                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3660                         $redirectArticle = WikiPage::factory( $this );
3661                         $newid = $redirectArticle->insertOn( $dbw );
3662                         if ( $newid ) { // sanity
3663                                 $redirectRevision = new Revision( array(
3664                                         'page'    => $newid,
3665                                         'comment' => $comment,
3666                                         'text'    => $redirectText ) );
3667                                 $redirectRevision->insertOn( $dbw );
3668                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3669
3670                                 wfRunHooks( 'NewRevisionFromEditComplete',
3671                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3672
3673                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3674                         }
3675                 }
3676
3677                 # Log the move
3678                 $logid = $logEntry->insert();
3679                 $logEntry->publish( $logid );
3680         }
3681
3682         /**
3683          * Move this page's subpages to be subpages of $nt
3684          *
3685          * @param $nt Title Move target
3686          * @param $auth bool Whether $wgUser's permissions should be checked
3687          * @param $reason string The reason for the move
3688          * @param $createRedirect bool Whether to create redirects from the old subpages to
3689          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3690          * @return mixed array with old page titles as keys, and strings (new page titles) or
3691          *     arrays (errors) as values, or an error array with numeric indices if no pages
3692          *     were moved
3693          */
3694         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3695                 global $wgMaximumMovedPages;
3696                 // Check permissions
3697                 if ( !$this->userCan( 'move-subpages' ) ) {
3698                         return array( 'cant-move-subpages' );
3699                 }
3700                 // Do the source and target namespaces support subpages?
3701                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3702                         return array( 'namespace-nosubpages',
3703                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3704                 }
3705                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3706                         return array( 'namespace-nosubpages',
3707                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3708                 }
3709
3710                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3711                 $retval = array();
3712                 $count = 0;
3713                 foreach ( $subpages as $oldSubpage ) {
3714                         $count++;
3715                         if ( $count > $wgMaximumMovedPages ) {
3716                                 $retval[$oldSubpage->getPrefixedTitle()] =
3717                                                 array( 'movepage-max-pages',
3718                                                         $wgMaximumMovedPages );
3719                                 break;
3720                         }
3721
3722                         // We don't know whether this function was called before
3723                         // or after moving the root page, so check both
3724                         // $this and $nt
3725                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3726                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3727                         {
3728                                 // When moving a page to a subpage of itself,
3729                                 // don't move it twice
3730                                 continue;
3731                         }
3732                         $newPageName = preg_replace(
3733                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3734                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3735                                         $oldSubpage->getDBkey() );
3736                         if ( $oldSubpage->isTalkPage() ) {
3737                                 $newNs = $nt->getTalkPage()->getNamespace();
3738                         } else {
3739                                 $newNs = $nt->getSubjectPage()->getNamespace();
3740                         }
3741                         # Bug 14385: we need makeTitleSafe because the new page names may
3742                         # be longer than 255 characters.
3743                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3744
3745                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3746                         if ( $success === true ) {
3747                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3748                         } else {
3749                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3750                         }
3751                 }
3752                 return $retval;
3753         }
3754
3755         /**
3756          * Checks if this page is just a one-rev redirect.
3757          * Adds lock, so don't use just for light purposes.
3758          *
3759          * @return Bool
3760          */
3761         public function isSingleRevRedirect() {
3762                 $dbw = wfGetDB( DB_MASTER );
3763                 # Is it a redirect?
3764                 $row = $dbw->selectRow( 'page',
3765                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3766                         $this->pageCond(),
3767                         __METHOD__,
3768                         array( 'FOR UPDATE' )
3769                 );
3770                 # Cache some fields we may want
3771                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3772                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3773                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3774                 if ( !$this->mRedirect ) {
3775                         return false;
3776                 }
3777                 # Does the article have a history?
3778                 $row = $dbw->selectField( array( 'page', 'revision' ),
3779                         'rev_id',
3780                         array( 'page_namespace' => $this->getNamespace(),
3781                                 'page_title' => $this->getDBkey(),
3782                                 'page_id=rev_page',
3783                                 'page_latest != rev_id'
3784                         ),
3785                         __METHOD__,
3786                         array( 'FOR UPDATE' )
3787                 );
3788                 # Return true if there was no history
3789                 return ( $row === false );
3790         }
3791
3792         /**
3793          * Checks if $this can be moved to a given Title
3794          * - Selects for update, so don't call it unless you mean business
3795          *
3796          * @param $nt Title the new title to check
3797          * @return Bool
3798          */
3799         public function isValidMoveTarget( $nt ) {
3800                 # Is it an existing file?
3801                 if ( $nt->getNamespace() == NS_FILE ) {
3802                         $file = wfLocalFile( $nt );
3803                         if ( $file->exists() ) {
3804                                 wfDebug( __METHOD__ . ": file exists\n" );
3805                                 return false;
3806                         }
3807                 }
3808                 # Is it a redirect with no history?
3809                 if ( !$nt->isSingleRevRedirect() ) {
3810                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3811                         return false;
3812                 }
3813                 # Get the article text
3814                 $rev = Revision::newFromTitle( $nt );
3815                 if( !is_object( $rev ) ){
3816                         return false;
3817                 }
3818                 $text = $rev->getText();
3819                 # Does the redirect point to the source?
3820                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3821                 $m = array();
3822                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3823                         $redirTitle = Title::newFromText( $m[1] );
3824                         if ( !is_object( $redirTitle ) ||
3825                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3826                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3827                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3828                                 return false;
3829                         }
3830                 } else {
3831                         # Fail safe
3832                         wfDebug( __METHOD__ . ": failsafe\n" );
3833                         return false;
3834                 }
3835                 return true;
3836         }
3837
3838         /**
3839          * Get categories to which this Title belongs and return an array of
3840          * categories' names.
3841          *
3842          * @return Array of parents in the form:
3843          *        $parent => $currentarticle
3844          */
3845         public function getParentCategories() {
3846                 global $wgContLang;
3847
3848                 $data = array();
3849
3850                 $titleKey = $this->getArticleID();
3851
3852                 if ( $titleKey === 0 ) {
3853                         return $data;
3854                 }
3855
3856                 $dbr = wfGetDB( DB_SLAVE );
3857
3858                 $res = $dbr->select( 'categorylinks', '*',
3859                         array(
3860                                 'cl_from' => $titleKey,
3861                         ),
3862                         __METHOD__,
3863                         array()
3864                 );
3865
3866                 if ( $dbr->numRows( $res ) > 0 ) {
3867                         foreach ( $res as $row ) {
3868                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3869                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3870                         }
3871                 }
3872                 return $data;
3873         }
3874
3875         /**
3876          * Get a tree of parent categories
3877          *
3878          * @param $children Array with the children in the keys, to check for circular refs
3879          * @return Array Tree of parent categories
3880          */
3881         public function getParentCategoryTree( $children = array() ) {
3882                 $stack = array();
3883                 $parents = $this->getParentCategories();
3884
3885                 if ( $parents ) {
3886                         foreach ( $parents as $parent => $current ) {
3887                                 if ( array_key_exists( $parent, $children ) ) {
3888                                         # Circular reference
3889                                         $stack[$parent] = array();
3890                                 } else {
3891                                         $nt = Title::newFromText( $parent );
3892                                         if ( $nt ) {
3893                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3894                                         }
3895                                 }
3896                         }
3897                 }
3898
3899                 return $stack;
3900         }
3901
3902         /**
3903          * Get an associative array for selecting this title from
3904          * the "page" table
3905          *
3906          * @return Array suitable for the $where parameter of DB::select()
3907          */
3908         public function pageCond() {
3909                 if ( $this->mArticleID > 0 ) {
3910                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3911                         return array( 'page_id' => $this->mArticleID );
3912                 } else {
3913                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3914                 }
3915         }
3916
3917         /**
3918          * Get the revision ID of the previous revision
3919          *
3920          * @param $revId Int Revision ID. Get the revision that was before this one.
3921          * @param $flags Int Title::GAID_FOR_UPDATE
3922          * @return Int|Bool Old revision ID, or FALSE if none exists
3923          */
3924         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3925                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3926                 $revId = $db->selectField( 'revision', 'rev_id',
3927                         array(
3928                                 'rev_page' => $this->getArticleID( $flags ),
3929                                 'rev_id < ' . intval( $revId )
3930                         ),
3931                         __METHOD__,
3932                         array( 'ORDER BY' => 'rev_id DESC' )
3933                 );
3934
3935                 if ( $revId === false ) {
3936                         return false;
3937                 } else {
3938                         return intval( $revId );
3939                 }
3940         }
3941
3942         /**
3943          * Get the revision ID of the next revision
3944          *
3945          * @param $revId Int Revision ID. Get the revision that was after this one.
3946          * @param $flags Int Title::GAID_FOR_UPDATE
3947          * @return Int|Bool Next revision ID, or FALSE if none exists
3948          */
3949         public function getNextRevisionID( $revId, $flags = 0 ) {
3950                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3951                 $revId = $db->selectField( 'revision', 'rev_id',
3952                         array(
3953                                 'rev_page' => $this->getArticleID( $flags ),
3954                                 'rev_id > ' . intval( $revId )
3955                         ),
3956                         __METHOD__,
3957                         array( 'ORDER BY' => 'rev_id' )
3958                 );
3959
3960                 if ( $revId === false ) {
3961                         return false;
3962                 } else {
3963                         return intval( $revId );
3964                 }
3965         }
3966
3967         /**
3968          * Get the first revision of the page
3969          *
3970          * @param $flags Int Title::GAID_FOR_UPDATE
3971          * @return Revision|Null if page doesn't exist
3972          */
3973         public function getFirstRevision( $flags = 0 ) {
3974                 $pageId = $this->getArticleID( $flags );
3975                 if ( $pageId ) {
3976                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3977                         $row = $db->selectRow( 'revision', '*',
3978                                 array( 'rev_page' => $pageId ),
3979                                 __METHOD__,
3980                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3981                         );
3982                         if ( $row ) {
3983                                 return new Revision( $row );
3984                         }
3985                 }
3986                 return null;
3987         }
3988
3989         /**
3990          * Get the oldest revision timestamp of this page
3991          *
3992          * @param $flags Int Title::GAID_FOR_UPDATE
3993          * @return String: MW timestamp
3994          */
3995         public function getEarliestRevTime( $flags = 0 ) {
3996                 $rev = $this->getFirstRevision( $flags );
3997                 return $rev ? $rev->getTimestamp() : null;
3998         }
3999
4000         /**
4001          * Check if this is a new page
4002          *
4003          * @return bool
4004          */
4005         public function isNewPage() {
4006                 $dbr = wfGetDB( DB_SLAVE );
4007                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4008         }
4009
4010         /**
4011          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4012          *
4013          * @return bool
4014          */
4015         public function isBigDeletion() {
4016                 global $wgDeleteRevisionsLimit;
4017
4018                 if ( !$wgDeleteRevisionsLimit ) {
4019                         return false;
4020                 }
4021
4022                 $revCount = $this->estimateRevisionCount();
4023                 return $revCount > $wgDeleteRevisionsLimit;
4024         }
4025
4026         /**
4027          * Get the  approximate revision count of this page.
4028          *
4029          * @return int
4030          */
4031         public function estimateRevisionCount() {
4032                 if ( !$this->exists() ) {
4033                         return 0;
4034                 }
4035
4036                 if ( $this->mEstimateRevisions === null ) {
4037                         $dbr = wfGetDB( DB_SLAVE );
4038                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4039                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4040                 }
4041
4042                 return $this->mEstimateRevisions;
4043         }
4044
4045         /**
4046          * Get the number of revisions between the given revision.
4047          * Used for diffs and other things that really need it.
4048          *
4049          * @param $old int|Revision Old revision or rev ID (first before range)
4050          * @param $new int|Revision New revision or rev ID (first after range)
4051          * @return Int Number of revisions between these revisions.
4052          */
4053         public function countRevisionsBetween( $old, $new ) {
4054                 if ( !( $old instanceof Revision ) ) {
4055                         $old = Revision::newFromTitle( $this, (int)$old );
4056                 }
4057                 if ( !( $new instanceof Revision ) ) {
4058                         $new = Revision::newFromTitle( $this, (int)$new );
4059                 }
4060                 if ( !$old || !$new ) {
4061                         return 0; // nothing to compare
4062                 }
4063                 $dbr = wfGetDB( DB_SLAVE );
4064                 return (int)$dbr->selectField( 'revision', 'count(*)',
4065                         array(
4066                                 'rev_page' => $this->getArticleID(),
4067                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4068                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4069                         ),
4070                         __METHOD__
4071                 );
4072         }
4073
4074         /**
4075          * Get the number of authors between the given revision IDs.
4076          * Used for diffs and other things that really need it.
4077          *
4078          * @param $old int|Revision Old revision or rev ID (first before range)
4079          * @param $new int|Revision New revision or rev ID (first after range)
4080          * @param $limit Int Maximum number of authors
4081          * @return Int Number of revision authors between these revisions.
4082          */
4083         public function countAuthorsBetween( $old, $new, $limit ) {
4084                 if ( !( $old instanceof Revision ) ) {
4085                         $old = Revision::newFromTitle( $this, (int)$old );
4086                 }
4087                 if ( !( $new instanceof Revision ) ) {
4088                         $new = Revision::newFromTitle( $this, (int)$new );
4089                 }
4090                 if ( !$old || !$new ) {
4091                         return 0; // nothing to compare
4092                 }
4093                 $dbr = wfGetDB( DB_SLAVE );
4094                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4095                         array(
4096                                 'rev_page' => $this->getArticleID(),
4097                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4098                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4099                         ), __METHOD__,
4100                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4101                 );
4102                 return (int)$dbr->numRows( $res );
4103         }
4104
4105         /**
4106          * Compare with another title.
4107          *
4108          * @param $title Title
4109          * @return Bool
4110          */
4111         public function equals( Title $title ) {
4112                 // Note: === is necessary for proper matching of number-like titles.
4113                 return $this->getInterwiki() === $title->getInterwiki()
4114                         && $this->getNamespace() == $title->getNamespace()
4115                         && $this->getDBkey() === $title->getDBkey();
4116         }
4117
4118         /**
4119          * Check if this title is a subpage of another title
4120          *
4121          * @param $title Title
4122          * @return Bool
4123          */
4124         public function isSubpageOf( Title $title ) {
4125                 return $this->getInterwiki() === $title->getInterwiki()
4126                         && $this->getNamespace() == $title->getNamespace()
4127                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4128         }
4129
4130         /**
4131          * Check if page exists.  For historical reasons, this function simply
4132          * checks for the existence of the title in the page table, and will
4133          * thus return false for interwiki links, special pages and the like.
4134          * If you want to know if a title can be meaningfully viewed, you should
4135          * probably call the isKnown() method instead.
4136          *
4137          * @return Bool
4138          */
4139         public function exists() {
4140                 return $this->getArticleID() != 0;
4141         }
4142
4143         /**
4144          * Should links to this title be shown as potentially viewable (i.e. as
4145          * "bluelinks"), even if there's no record by this title in the page
4146          * table?
4147          *
4148          * This function is semi-deprecated for public use, as well as somewhat
4149          * misleadingly named.  You probably just want to call isKnown(), which
4150          * calls this function internally.
4151          *
4152          * (ISSUE: Most of these checks are cheap, but the file existence check
4153          * can potentially be quite expensive.  Including it here fixes a lot of
4154          * existing code, but we might want to add an optional parameter to skip
4155          * it and any other expensive checks.)
4156          *
4157          * @return Bool
4158          */
4159         public function isAlwaysKnown() {
4160                 $isKnown = null;
4161
4162                 /**
4163                  * Allows overriding default behaviour for determining if a page exists.
4164                  * If $isKnown is kept as null, regular checks happen. If it's
4165                  * a boolean, this value is returned by the isKnown method.
4166                  *
4167                  * @since 1.20
4168                  *
4169                  * @param Title $title
4170                  * @param boolean|null $isKnown
4171                  */
4172                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4173
4174                 if ( !is_null( $isKnown ) ) {
4175                         return $isKnown;
4176                 }
4177
4178                 if ( $this->mInterwiki != '' ) {
4179                         return true;  // any interwiki link might be viewable, for all we know
4180                 }
4181
4182                 switch( $this->mNamespace ) {
4183                         case NS_MEDIA:
4184                         case NS_FILE:
4185                                 // file exists, possibly in a foreign repo
4186                                 return (bool)wfFindFile( $this );
4187                         case NS_SPECIAL:
4188                                 // valid special page
4189                                 return SpecialPageFactory::exists( $this->getDBkey() );
4190                         case NS_MAIN:
4191                                 // selflink, possibly with fragment
4192                                 return $this->mDbkeyform == '';
4193                         case NS_MEDIAWIKI:
4194                                 // known system message
4195                                 return $this->hasSourceText() !== false;
4196                         default:
4197                                 return false;
4198                 }
4199         }
4200
4201         /**
4202          * Does this title refer to a page that can (or might) be meaningfully
4203          * viewed?  In particular, this function may be used to determine if
4204          * links to the title should be rendered as "bluelinks" (as opposed to
4205          * "redlinks" to non-existent pages).
4206          * Adding something else to this function will cause inconsistency
4207          * since LinkHolderArray calls isAlwaysKnown() and does its own
4208          * page existence check.
4209          *
4210          * @return Bool
4211          */
4212         public function isKnown() {
4213                 return $this->isAlwaysKnown() || $this->exists();
4214         }
4215
4216         /**
4217          * Does this page have source text?
4218          *
4219          * @return Boolean
4220          */
4221         public function hasSourceText() {
4222                 if ( $this->exists() ) {
4223                         return true;
4224                 }
4225
4226                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4227                         // If the page doesn't exist but is a known system message, default
4228                         // message content will be displayed, same for language subpages-
4229                         // Use always content language to avoid loading hundreds of languages
4230                         // to get the link color.
4231                         global $wgContLang;
4232                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4233                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4234                         return $message->exists();
4235                 }
4236
4237                 return false;
4238         }
4239
4240         /**
4241          * Get the default message text or false if the message doesn't exist
4242          *
4243          * @return String or false
4244          */
4245         public function getDefaultMessageText() {
4246                 global $wgContLang;
4247
4248                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4249                         return false;
4250                 }
4251
4252                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4253                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4254
4255                 if ( $message->exists() ) {
4256                         return $message->plain();
4257                 } else {
4258                         return false;
4259                 }
4260         }
4261
4262         /**
4263          * Updates page_touched for this page; called from LinksUpdate.php
4264          *
4265          * @return Bool true if the update succeded
4266          */
4267         public function invalidateCache() {
4268                 if ( wfReadOnly() ) {
4269                         return false;
4270                 }
4271                 $dbw = wfGetDB( DB_MASTER );
4272                 $success = $dbw->update(
4273                         'page',
4274                         array( 'page_touched' => $dbw->timestamp() ),
4275                         $this->pageCond(),
4276                         __METHOD__
4277                 );
4278                 HTMLFileCache::clearFileCache( $this );
4279                 return $success;
4280         }
4281
4282         /**
4283          * Update page_touched timestamps and send squid purge messages for
4284          * pages linking to this title. May be sent to the job queue depending
4285          * on the number of links. Typically called on create and delete.
4286          */
4287         public function touchLinks() {
4288                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4289                 $u->doUpdate();
4290
4291                 if ( $this->getNamespace() == NS_CATEGORY ) {
4292                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4293                         $u->doUpdate();
4294                 }
4295         }
4296
4297         /**
4298          * Get the last touched timestamp
4299          *
4300          * @param $db DatabaseBase: optional db
4301          * @return String last-touched timestamp
4302          */
4303         public function getTouched( $db = null ) {
4304                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4305                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4306                 return $touched;
4307         }
4308
4309         /**
4310          * Get the timestamp when this page was updated since the user last saw it.
4311          *
4312          * @param $user User
4313          * @return String|Null
4314          */
4315         public function getNotificationTimestamp( $user = null ) {
4316                 global $wgUser, $wgShowUpdatedMarker;
4317                 // Assume current user if none given
4318                 if ( !$user ) {
4319                         $user = $wgUser;
4320                 }
4321                 // Check cache first
4322                 $uid = $user->getId();
4323                 // avoid isset here, as it'll return false for null entries
4324                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4325                         return $this->mNotificationTimestamp[$uid];
4326                 }
4327                 if ( !$uid || !$wgShowUpdatedMarker ) {
4328                         return $this->mNotificationTimestamp[$uid] = false;
4329                 }
4330                 // Don't cache too much!
4331                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4332                         $this->mNotificationTimestamp = array();
4333                 }
4334                 $dbr = wfGetDB( DB_SLAVE );
4335                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4336                         'wl_notificationtimestamp',
4337                         array(
4338                                 'wl_user' => $user->getId(),
4339                                 'wl_namespace' => $this->getNamespace(),
4340                                 'wl_title' => $this->getDBkey(),
4341                         ),
4342                         __METHOD__
4343                 );
4344                 return $this->mNotificationTimestamp[$uid];
4345         }
4346
4347         /**
4348          * Generate strings used for xml 'id' names in monobook tabs
4349          *
4350          * @param $prepend string defaults to 'nstab-'
4351          * @return String XML 'id' name
4352          */
4353         public function getNamespaceKey( $prepend = 'nstab-' ) {
4354                 global $wgContLang;
4355                 // Gets the subject namespace if this title
4356                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4357                 // Checks if cononical namespace name exists for namespace
4358                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4359                         // Uses canonical namespace name
4360                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4361                 } else {
4362                         // Uses text of namespace
4363                         $namespaceKey = $this->getSubjectNsText();
4364                 }
4365                 // Makes namespace key lowercase
4366                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4367                 // Uses main
4368                 if ( $namespaceKey == '' ) {
4369                         $namespaceKey = 'main';
4370                 }
4371                 // Changes file to image for backwards compatibility
4372                 if ( $namespaceKey == 'file' ) {
4373                         $namespaceKey = 'image';
4374                 }
4375                 return $prepend . $namespaceKey;
4376         }
4377
4378         /**
4379          * Get all extant redirects to this Title
4380          *
4381          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4382          * @return Array of Title redirects to this title
4383          */
4384         public function getRedirectsHere( $ns = null ) {
4385                 $redirs = array();
4386
4387                 $dbr = wfGetDB( DB_SLAVE );
4388                 $where = array(
4389                         'rd_namespace' => $this->getNamespace(),
4390                         'rd_title' => $this->getDBkey(),
4391                         'rd_from = page_id'
4392                 );
4393                 if ( !is_null( $ns ) ) {
4394                         $where['page_namespace'] = $ns;
4395                 }
4396
4397                 $res = $dbr->select(
4398                         array( 'redirect', 'page' ),
4399                         array( 'page_namespace', 'page_title' ),
4400                         $where,
4401                         __METHOD__
4402                 );
4403
4404                 foreach ( $res as $row ) {
4405                         $redirs[] = self::newFromRow( $row );
4406                 }
4407                 return $redirs;
4408         }
4409
4410         /**
4411          * Check if this Title is a valid redirect target
4412          *
4413          * @return Bool
4414          */
4415         public function isValidRedirectTarget() {
4416                 global $wgInvalidRedirectTargets;
4417
4418                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4419                 if ( $this->isSpecial( 'Userlogout' ) ) {
4420                         return false;
4421                 }
4422
4423                 foreach ( $wgInvalidRedirectTargets as $target ) {
4424                         if ( $this->isSpecial( $target ) ) {
4425                                 return false;
4426                         }
4427                 }
4428
4429                 return true;
4430         }
4431
4432         /**
4433          * Get a backlink cache object
4434          *
4435          * @return BacklinkCache
4436          */
4437         function getBacklinkCache() {
4438                 if ( is_null( $this->mBacklinkCache ) ) {
4439                         $this->mBacklinkCache = new BacklinkCache( $this );
4440                 }
4441                 return $this->mBacklinkCache;
4442         }
4443
4444         /**
4445          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4446          *
4447          * @return Boolean
4448          */
4449         public function canUseNoindex() {
4450                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4451
4452                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4453                         ? $wgContentNamespaces
4454                         : $wgExemptFromUserRobotsControl;
4455
4456                 return !in_array( $this->mNamespace, $bannedNamespaces );
4457
4458         }
4459
4460         /**
4461          * Returns the raw sort key to be used for categories, with the specified
4462          * prefix.  This will be fed to Collation::getSortKey() to get a
4463          * binary sortkey that can be used for actual sorting.
4464          *
4465          * @param $prefix string The prefix to be used, specified using
4466          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4467          *   prefix.
4468          * @return string
4469          */
4470         public function getCategorySortkey( $prefix = '' ) {
4471                 $unprefixed = $this->getText();
4472
4473                 // Anything that uses this hook should only depend
4474                 // on the Title object passed in, and should probably
4475                 // tell the users to run updateCollations.php --force
4476                 // in order to re-sort existing category relations.
4477                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4478                 if ( $prefix !== '' ) {
4479                         # Separate with a line feed, so the unprefixed part is only used as
4480                         # a tiebreaker when two pages have the exact same prefix.
4481                         # In UCA, tab is the only character that can sort above LF
4482                         # so we strip both of them from the original prefix.
4483                         $prefix = strtr( $prefix, "\n\t", '  ' );
4484                         return "$prefix\n$unprefixed";
4485                 }
4486                 return $unprefixed;
4487         }
4488
4489         /**
4490          * Get the language in which the content of this page is written.
4491          * Defaults to $wgContLang, but in certain cases it can be e.g.
4492          * $wgLang (such as special pages, which are in the user language).
4493          *
4494          * @since 1.18
4495          * @return Language
4496          */
4497         public function getPageLanguage() {
4498                 global $wgLang;
4499                 if ( $this->isSpecialPage() ) {
4500                         // special pages are in the user language
4501                         return $wgLang;
4502                 } elseif ( $this->isCssOrJsPage() || $this->isCssJsSubpage() ) {
4503                         // css/js should always be LTR and is, in fact, English
4504                         return wfGetLangObj( 'en' );
4505                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4506                         // Parse mediawiki messages with correct target language
4507                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4508                         return wfGetLangObj( $lang );
4509                 }
4510                 global $wgContLang;
4511                 // If nothing special, it should be in the wiki content language
4512                 $pageLang = $wgContLang;
4513                 // Hook at the end because we don't want to override the above stuff
4514                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4515                 return wfGetLangObj( $pageLang );
4516         }
4517 }