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         var $mContentModel = false;       // /< ID of the page's content model, i.e. one of the CONTENT_MODEL_XXX constants
  69         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  70         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  71         var $mOldRestrictions = false;
  72         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  73         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  74         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  75         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  76         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  77         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  78         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  79         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  80         # Don't change the following default, NS_MAIN is hardcoded in several
  81         # places.  See bug 696.
  82         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  83                                                                           # Zero except in {{transclusion}} tags
  84         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  85         var $mLength = -1;                // /< The page length, 0 for special pages
  86         var $mRedirect = null;            // /< Is the article at this title a redirect?
  87         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  88         var $mBacklinkCache = null;       // /< Cache of links to this title
  89         var $mHasSubpage;                 // /< Whether a page has any subpages
  90         // @}
  91
  92
  93         /**
  94          * Constructor
  95          */
  96         /*protected*/ function __construct() { }
  97
  98         /**
  99          * Create a new Title from a prefixed DB key
 100          *
 101          * @param $key String the database key, which has underscores
 102          *      instead of spaces, possibly including namespace and
 103          *      interwiki prefixes
 104          * @return Title, or NULL on an error
 105          */
 106         public static function newFromDBkey( $key ) {
 107                 $t = new Title();
 108                 $t->mDbkeyform = $key;
 109                 if ( $t->secureAndSplit() ) {
 110                         return $t;
 111                 } else {
 112                         return null;
 113                 }
 114         }
 115
 116         /**
 117          * Create a new Title from text, such as what one would find in a link. De-
 118          * codes any HTML entities in the text.
 119          *
 120          * @param $text String the link text; spaces, prefixes, and an
 121          *   initial ':' indicating the main namespace are accepted.
 122          * @param $defaultNamespace Int the namespace to use if none is speci-
 123          *   fied by a prefix.  If you want to force a specific namespace even if
 124          *   $text might begin with a namespace prefix, use makeTitle() or
 125          *   makeTitleSafe().
 126          * @throws MWException
 127          * @return Title|null - Title or null on an error.
 128          */
 129         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 130                 if ( is_object( $text ) ) {
 131                         throw new MWException( 'Title::newFromText given an object' );
 132                 }
 133
 134                 /**
 135                  * Wiki pages often contain multiple links to the same page.
 136                  * Title normalization and parsing can become expensive on
 137                  * pages with many links, so we can save a little time by
 138                  * caching them.
 139                  *
 140                  * In theory these are value objects and won't get changed...
 141                  */
 142                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 143                         return Title::$titleCache[$text];
 144                 }
 145
 146                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 147                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 148
 149                 $t = new Title();
 150                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 151                 $t->mDefaultNamespace = $defaultNamespace;
 152
 153                 static $cachedcount = 0 ;
 154                 if ( $t->secureAndSplit() ) {
 155                         if ( $defaultNamespace == NS_MAIN ) {
 156                                 if ( $cachedcount >= self::CACHE_MAX ) {
 157                                         # Avoid memory leaks on mass operations...
 158                                         Title::$titleCache = array();
 159                                         $cachedcount = 0;
 160                                 }
 161                                 $cachedcount++;
 162                                 Title::$titleCache[$text] =& $t;
 163                         }
 164                         return $t;
 165                 } else {
 166                         $ret = null;
 167                         return $ret;
 168                 }
 169         }
 170
 171         /**
 172          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 173          *
 174          * Example of wrong and broken code:
 175          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 176          *
 177          * Example of right code:
 178          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 179          *
 180          * Create a new Title from URL-encoded text. Ensures that
 181          * the given title's length does not exceed the maximum.
 182          *
 183          * @param $url String the title, as might be taken from a URL
 184          * @return Title the new object, or NULL on an error
 185          */
 186         public static function newFromURL( $url ) {
 187                 $t = new Title();
 188
 189                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 190                 # but some URLs used it as a space replacement and they still come
 191                 # from some external search tools.
 192                 if ( strpos( self::legalChars(), '+' ) === false ) {
 193                         $url = str_replace( '+', ' ', $url );
 194                 }
 195
 196                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 197                 if ( $t->secureAndSplit() ) {
 198                         return $t;
 199                 } else {
 200                         return null;
 201                 }
 202         }
 203
 204         /**
 205          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 206          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 207          *
 208          * @return array
 209          */
 210         protected static function getSelectFields() {
 211                 global $wgContentHandlerUseDB;
 212
 213                 $fields = array(
 214                         'page_namespace', 'page_title', 'page_id',
 215                         'page_len', 'page_is_redirect', 'page_latest',
 216                 );
 217
 218                 if ( $wgContentHandlerUseDB ) {
 219                         $fields[] = 'page_content_model';
 220                 }
 221
 222                 return $fields;
 223         }
 224
 225         /**
 226          * Create a new Title from an article ID
 227          *
 228          * @param $id Int the page_id corresponding to the Title to create
 229          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 230          * @return Title the new object, or NULL on an error
 231          */
 232         public static function newFromID( $id, $flags = 0 ) {
 233                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 234                 $row = $db->selectRow(
 235                         'page',
 236                         self::getSelectFields(),
 237                         array( 'page_id' => $id ),
 238                         __METHOD__
 239                 );
 240                 if ( $row !== false ) {
 241                         $title = Title::newFromRow( $row );
 242                 } else {
 243                         $title = null;
 244                 }
 245                 return $title;
 246         }
 247
 248         /**
 249          * Make an array of titles from an array of IDs
 250          *
 251          * @param $ids Array of Int Array of IDs
 252          * @return Array of Titles
 253          */
 254         public static function newFromIDs( $ids ) {
 255                 if ( !count( $ids ) ) {
 256                         return array();
 257                 }
 258                 $dbr = wfGetDB( DB_SLAVE );
 259
 260                 $res = $dbr->select(
 261                         'page',
 262                         self::getSelectFields(),
 263                         array( 'page_id' => $ids ),
 264                         __METHOD__
 265                 );
 266
 267                 $titles = array();
 268                 foreach ( $res as $row ) {
 269                         $titles[] = Title::newFromRow( $row );
 270                 }
 271                 return $titles;
 272         }
 273
 274         /**
 275          * Make a Title object from a DB row
 276          *
 277          * @param $row Object database row (needs at least page_title,page_namespace)
 278          * @return Title corresponding Title
 279          */
 280         public static function newFromRow( $row ) {
 281                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 282                 $t->loadFromRow( $row );
 283                 return $t;
 284         }
 285
 286         /**
 287          * Load Title object fields from a DB row.
 288          * If false is given, the title will be treated as non-existing.
 289          *
 290          * @param $row Object|bool database row
 291          */
 292         public function loadFromRow( $row ) {
 293                 if ( $row ) { // page found
 294                         if ( isset( $row->page_id ) )
 295                                 $this->mArticleID = (int)$row->page_id;
 296                         if ( isset( $row->page_len ) )
 297                                 $this->mLength = (int)$row->page_len;
 298                         if ( isset( $row->page_is_redirect ) )
 299                                 $this->mRedirect = (bool)$row->page_is_redirect;
 300                         if ( isset( $row->page_latest ) )
 301                                 $this->mLatestID = (int)$row->page_latest;
 302                         if ( isset( $row->page_content_model ) )
 303                                 $this->mContentModel = strval( $row->page_content_model );
 304                         else
 305                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 306                 } else { // page not found
 307                         $this->mArticleID = 0;
 308                         $this->mLength = 0;
 309                         $this->mRedirect = false;
 310                         $this->mLatestID = 0;
 311                         $this->mContentModel = false; # initialized lazily in getContentModel()
 312                 }
 313         }
 314
 315         /**
 316          * Create a new Title from a namespace index and a DB key.
 317          * It's assumed that $ns and $title are *valid*, for instance when
 318          * they came directly from the database or a special page name.
 319          * For convenience, spaces are converted to underscores so that
 320          * eg user_text fields can be used directly.
 321          *
 322          * @param $ns Int the namespace of the article
 323          * @param $title String the unprefixed database key form
 324          * @param $fragment String the link fragment (after the "#")
 325          * @param $interwiki String the interwiki prefix
 326          * @return Title the new object
 327          */
 328         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 329                 $t = new Title();
 330                 $t->mInterwiki = $interwiki;
 331                 $t->mFragment = $fragment;
 332                 $t->mNamespace = $ns = intval( $ns );
 333                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 334                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 335                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 336                 $t->mTextform = str_replace( '_', ' ', $title );
 337                 $t->mContentModel = false; # initialized lazily in getContentModel()
 338                 return $t;
 339         }
 340
 341         /**
 342          * Create a new Title from a namespace index and a DB key.
 343          * The parameters will be checked for validity, which is a bit slower
 344          * than makeTitle() but safer for user-provided data.
 345          *
 346          * @param $ns Int the namespace of the article
 347          * @param $title String database key form
 348          * @param $fragment String the link fragment (after the "#")
 349          * @param $interwiki String interwiki prefix
 350          * @return Title the new object, or NULL on an error
 351          */
 352         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 353                 if ( !MWNamespace::exists( $ns ) ) {
 354                         return null;
 355                 }
 356
 357                 $t = new Title();
 358                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 359                 if ( $t->secureAndSplit() ) {
 360                         return $t;
 361                 } else {
 362                         return null;
 363                 }
 364         }
 365
 366         /**
 367          * Create a new Title for the Main Page
 368          *
 369          * @return Title the new object
 370          */
 371         public static function newMainPage() {
 372                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 373                 // Don't give fatal errors if the message is broken
 374                 if ( !$title ) {
 375                         $title = Title::newFromText( 'Main Page' );
 376                 }
 377                 return $title;
 378         }
 379
 380         /**
 381          * Extract a redirect destination from a string and return the
 382          * Title, or null if the text doesn't contain a valid redirect
 383          * This will only return the very next target, useful for
 384          * the redirect table and other checks that don't need full recursion
 385          *
 386          * @param $text String: Text with possible redirect
 387          * @return Title: The corresponding Title
 388          * @deprecated since 1.WD, use Content::getRedirectTarget instead.
 389          */
 390         public static function newFromRedirect( $text ) {
 391                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 392                 return $content->getRedirectTarget();
 393         }
 394
 395         /**
 396          * Extract a redirect destination from a string and return the
 397          * Title, or null if the text doesn't contain a valid redirect
 398          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 399          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 400          *
 401          * @param $text String Text with possible redirect
 402          * @return Title
 403          * @deprecated since 1.WD, use Content::getUltimateRedirectTarget instead.
 404          */
 405         public static function newFromRedirectRecurse( $text ) {
 406                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 407                 return $content->getUltimateRedirectTarget();
 408         }
 409
 410         /**
 411          * Extract a redirect destination from a string and return an
 412          * array of Titles, or null if the text doesn't contain a valid redirect
 413          * The last element in the array is the final destination after all redirects
 414          * have been resolved (up to $wgMaxRedirects times)
 415          *
 416          * @param $text String Text with possible redirect
 417          * @return Array of Titles, with the destination last
 418          * @deprecated since 1.WD, use Content::getRedirectChain instead.
 419          */
 420         public static function newFromRedirectArray( $text ) {
 421                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 422                 return $content->getRedirectChain();
 423         }
 424
 425         /**
 426          * Get the prefixed DB key associated with an ID
 427          *
 428          * @param $id Int the page_id of the article
 429          * @return Title an object representing the article, or NULL if no such article was found
 430          */
 431         public static function nameOf( $id ) {
 432                 $dbr = wfGetDB( DB_SLAVE );
 433
 434                 $s = $dbr->selectRow(
 435                         'page',
 436                         array( 'page_namespace', 'page_title' ),
 437                         array( 'page_id' => $id ),
 438                         __METHOD__
 439                 );
 440                 if ( $s === false ) {
 441                         return null;
 442                 }
 443
 444                 $n = self::makeName( $s->page_namespace, $s->page_title );
 445                 return $n;
 446         }
 447
 448         /**
 449          * Get a regex character class describing the legal characters in a link
 450          *
 451          * @return String the list of characters, not delimited
 452          */
 453         public static function legalChars() {
 454                 global $wgLegalTitleChars;
 455                 return $wgLegalTitleChars;
 456         }
 457
 458         /**
 459          * Returns a simple regex that will match on characters and sequences invalid in titles.
 460          * Note that this doesn't pick up many things that could be wrong with titles, but that
 461          * replacing this regex with something valid will make many titles valid.
 462          *
 463          * @return String regex string
 464          */
 465         static function getTitleInvalidRegex() {
 466                 static $rxTc = false;
 467                 if ( !$rxTc ) {
 468                         # Matching titles will be held as illegal.
 469                         $rxTc = '/' .
 470                                 # Any character not allowed is forbidden...
 471                                 '[^' . self::legalChars() . ']' .
 472                                 # URL percent encoding sequences interfere with the ability
 473                                 # to round-trip titles -- you can't link to them consistently.
 474                                 '|%[0-9A-Fa-f]{2}' .
 475                                 # XML/HTML character references produce similar issues.
 476                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 477                                 '|&#[0-9]+;' .
 478                                 '|&#x[0-9A-Fa-f]+;' .
 479                                 '/S';
 480                 }
 481
 482                 return $rxTc;
 483         }
 484
 485         /**
 486          * Get a string representation of a title suitable for
 487          * including in a search index
 488          *
 489          * @param $ns Int a namespace index
 490          * @param $title String text-form main part
 491          * @return String a stripped-down title string ready for the search index
 492          */
 493         public static function indexTitle( $ns, $title ) {
 494                 global $wgContLang;
 495
 496                 $lc = SearchEngine::legalSearchChars() . '&#;';
 497                 $t = $wgContLang->normalizeForSearch( $title );
 498                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 499                 $t = $wgContLang->lc( $t );
 500
 501                 # Handle 's, s'
 502                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 503                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 504
 505                 $t = preg_replace( "/\\s+/", ' ', $t );
 506
 507                 if ( $ns == NS_FILE ) {
 508                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 509                 }
 510                 return trim( $t );
 511         }
 512
 513         /**
 514          * Make a prefixed DB key from a DB key and a namespace index
 515          *
 516          * @param $ns Int numerical representation of the namespace
 517          * @param $title String the DB key form the title
 518          * @param $fragment String The link fragment (after the "#")
 519          * @param $interwiki String The interwiki prefix
 520          * @return String the prefixed form of the title
 521          */
 522         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 523                 global $wgContLang;
 524
 525                 $namespace = $wgContLang->getNsText( $ns );
 526                 $name = $namespace == '' ? $title : "$namespace:$title";
 527                 if ( strval( $interwiki ) != '' ) {
 528                         $name = "$interwiki:$name";
 529                 }
 530                 if ( strval( $fragment ) != '' ) {
 531                         $name .= '#' . $fragment;
 532                 }
 533                 return $name;
 534         }
 535
 536         /**
 537          * Escape a text fragment, say from a link, for a URL
 538          *
 539          * @param $fragment string containing a URL or link fragment (after the "#")
 540          * @return String: escaped string
 541          */
 542         static function escapeFragmentForURL( $fragment ) {
 543                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 544                 # fragments appear not to work in IE (at least up to 7) or in at least
 545                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 546                 # to care if they aren't encoded.
 547                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 548         }
 549
 550         /**
 551          * Callback for usort() to do title sorts by (namespace, title)
 552          *
 553          * @param $a Title
 554          * @param $b Title
 555          *
 556          * @return Integer: result of string comparison, or namespace comparison
 557          */
 558         public static function compare( $a, $b ) {
 559                 if ( $a->getNamespace() == $b->getNamespace() ) {
 560                         return strcmp( $a->getText(), $b->getText() );
 561                 } else {
 562                         return $a->getNamespace() - $b->getNamespace();
 563                 }
 564         }
 565
 566         /**
 567          * Determine whether the object refers to a page within
 568          * this project.
 569          *
 570          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 571          */
 572         public function isLocal() {
 573                 if ( $this->mInterwiki != '' ) {
 574                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 575                 } else {
 576                         return true;
 577                 }
 578         }
 579
 580         /**
 581          * Is this Title interwiki?
 582          *
 583          * @return Bool
 584          */
 585         public function isExternal() {
 586                 return ( $this->mInterwiki != '' );
 587         }
 588
 589         /**
 590          * Get the interwiki prefix (or null string)
 591          *
 592          * @return String Interwiki prefix
 593          */
 594         public function getInterwiki() {
 595                 return $this->mInterwiki;
 596         }
 597
 598         /**
 599          * Determine whether the object refers to a page within
 600          * this project and is transcludable.
 601          *
 602          * @return Bool TRUE if this is transcludable
 603          */
 604         public function isTrans() {
 605                 if ( $this->mInterwiki == '' ) {
 606                         return false;
 607                 }
 608
 609                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 610         }
 611
 612         /**
 613          * Returns the DB name of the distant wiki which owns the object.
 614          *
 615          * @return String the DB name
 616          */
 617         public function getTransWikiID() {
 618                 if ( $this->mInterwiki == '' ) {
 619                         return false;
 620                 }
 621
 622                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 623         }
 624
 625         /**
 626          * Get the text form (spaces not underscores) of the main part
 627          *
 628          * @return String Main part of the title
 629          */
 630         public function getText() {
 631                 return $this->mTextform;
 632         }
 633
 634         /**
 635          * Get the URL-encoded form of the main part
 636          *
 637          * @return String Main part of the title, URL-encoded
 638          */
 639         public function getPartialURL() {
 640                 return $this->mUrlform;
 641         }
 642
 643         /**
 644          * Get the main part with underscores
 645          *
 646          * @return String: Main part of the title, with underscores
 647          */
 648         public function getDBkey() {
 649                 return $this->mDbkeyform;
 650         }
 651
 652         /**
 653          * Get the DB key with the initial letter case as specified by the user
 654          *
 655          * @return String DB key
 656          */
 657         function getUserCaseDBKey() {
 658                 return $this->mUserCaseDBKey;
 659         }
 660
 661         /**
 662          * Get the namespace index, i.e. one of the NS_xxxx constants.
 663          *
 664          * @return Integer: Namespace index
 665          */
 666         public function getNamespace() {
 667                 return $this->mNamespace;
 668         }
 669
 670         /**
 671          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 672          *
 673          * @return String: Content model id
 674          */
 675         public function getContentModel() {
 676                 if ( !$this->mContentModel ) {
 677                         $linkCache = LinkCache::singleton();
 678                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 679                 }
 680
 681                 if ( !$this->mContentModel ) {
 682                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 683                 }
 684
 685                 if( !$this->mContentModel ) {
 686                         throw new MWException( "failed to determin content model!" );
 687                 }
 688
 689                 return $this->mContentModel;
 690         }
 691
 692         /**
 693          * Convenience method for checking a title's content model name
 694          *
 695          * @param int $id
 696          * @return Boolean true if $this->getContentModel() == $id
 697          */
 698         public function hasContentModel( $id ) {
 699                 return $this->getContentModel() == $id;
 700         }
 701
 702         /**
 703          * Get the namespace text
 704          *
 705          * @return String: Namespace text
 706          */
 707         public function getNsText() {
 708                 global $wgContLang;
 709
 710                 if ( $this->mInterwiki != '' ) {
 711                         // This probably shouldn't even happen. ohh man, oh yuck.
 712                         // But for interwiki transclusion it sometimes does.
 713                         // Shit. Shit shit shit.
 714                         //
 715                         // Use the canonical namespaces if possible to try to
 716                         // resolve a foreign namespace.
 717                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 718                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 719                         }
 720                 }
 721
 722                 if ( $wgContLang->needsGenderDistinction() &&
 723                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 724                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 725                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 726                 }
 727
 728                 return $wgContLang->getNsText( $this->mNamespace );
 729         }
 730
 731         /**
 732          * Get the namespace text of the subject (rather than talk) page
 733          *
 734          * @return String Namespace text
 735          */
 736         public function getSubjectNsText() {
 737                 global $wgContLang;
 738                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 739         }
 740
 741         /**
 742          * Get the namespace text of the talk page
 743          *
 744          * @return String Namespace text
 745          */
 746         public function getTalkNsText() {
 747                 global $wgContLang;
 748                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 749         }
 750
 751         /**
 752          * Could this title have a corresponding talk page?
 753          *
 754          * @return Bool TRUE or FALSE
 755          */
 756         public function canTalk() {
 757                 return( MWNamespace::canTalk( $this->mNamespace ) );
 758         }
 759
 760         /**
 761          * Is this in a namespace that allows actual pages?
 762          *
 763          * @return Bool
 764          * @internal note -- uses hardcoded namespace index instead of constants
 765          */
 766         public function canExist() {
 767                 return $this->mNamespace >= NS_MAIN;
 768         }
 769
 770         /**
 771          * Can this title be added to a user's watchlist?
 772          *
 773          * @return Bool TRUE or FALSE
 774          */
 775         public function isWatchable() {
 776                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 777         }
 778
 779         /**
 780          * Returns true if this is a special page.
 781          *
 782          * @return boolean
 783          */
 784         public function isSpecialPage() {
 785                 return $this->getNamespace() == NS_SPECIAL;
 786         }
 787
 788         /**
 789          * Returns true if this title resolves to the named special page
 790          *
 791          * @param $name String The special page name
 792          * @return boolean
 793          */
 794         public function isSpecial( $name ) {
 795                 if ( $this->isSpecialPage() ) {
 796                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 797                         if ( $name == $thisName ) {
 798                                 return true;
 799                         }
 800                 }
 801                 return false;
 802         }
 803
 804         /**
 805          * If the Title refers to a special page alias which is not the local default, resolve
 806          * the alias, and localise the name as necessary.  Otherwise, return $this
 807          *
 808          * @return Title
 809          */
 810         public function fixSpecialName() {
 811                 if ( $this->isSpecialPage() ) {
 812                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 813                         if ( $canonicalName ) {
 814                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 815                                 if ( $localName != $this->mDbkeyform ) {
 816                                         return Title::makeTitle( NS_SPECIAL, $localName );
 817                                 }
 818                         }
 819                 }
 820                 return $this;
 821         }
 822
 823         /**
 824          * Returns true if the title is inside the specified namespace.
 825          *
 826          * Please make use of this instead of comparing to getNamespace()
 827          * This function is much more resistant to changes we may make
 828          * to namespaces than code that makes direct comparisons.
 829          * @param $ns int The namespace
 830          * @return bool
 831          * @since 1.19
 832          */
 833         public function inNamespace( $ns ) {
 834                 return MWNamespace::equals( $this->getNamespace(), $ns );
 835         }
 836
 837         /**
 838          * Returns true if the title is inside one of the specified namespaces.
 839          *
 840          * @param ...$namespaces The namespaces to check for
 841          * @return bool
 842          * @since 1.19
 843          */
 844         public function inNamespaces( /* ... */ ) {
 845                 $namespaces = func_get_args();
 846                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 847                         $namespaces = $namespaces[0];
 848                 }
 849
 850                 foreach ( $namespaces as $ns ) {
 851                         if ( $this->inNamespace( $ns ) ) {
 852                                 return true;
 853                         }
 854                 }
 855
 856                 return false;
 857         }
 858
 859         /**
 860          * Returns true if the title has the same subject namespace as the
 861          * namespace specified.
 862          * For example this method will take NS_USER and return true if namespace
 863          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 864          * as their subject namespace.
 865          *
 866          * This is MUCH simpler than individually testing for equivilance
 867          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 868          * @since 1.19
 869          * @param $ns int
 870          * @return bool
 871          */
 872         public function hasSubjectNamespace( $ns ) {
 873                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 874         }
 875
 876         /**
 877          * Is this Title in a namespace which contains content?
 878          * In other words, is this a content page, for the purposes of calculating
 879          * statistics, etc?
 880          *
 881          * @return Boolean
 882          */
 883         public function isContentPage() {
 884                 return MWNamespace::isContent( $this->getNamespace() );
 885         }
 886
 887         /**
 888          * Would anybody with sufficient privileges be able to move this page?
 889          * Some pages just aren't movable.
 890          *
 891          * @return Bool TRUE or FALSE
 892          */
 893         public function isMovable() {
 894                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 895                         // Interwiki title or immovable namespace. Hooks don't get to override here
 896                         return false;
 897                 }
 898
 899                 $result = true;
 900                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 901                 return $result;
 902         }
 903
 904         /**
 905          * Is this the mainpage?
 906          * @note Title::newFromText seams to be sufficiently optimized by the title
 907          * cache that we don't need to over-optimize by doing direct comparisons and
 908          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 909          * ends up reporting something differently than $title->isMainPage();
 910          *
 911          * @since 1.18
 912          * @return Bool
 913          */
 914         public function isMainPage() {
 915                 return $this->equals( Title::newMainPage() );
 916         }
 917
 918         /**
 919          * Is this a subpage?
 920          *
 921          * @return Bool
 922          */
 923         public function isSubpage() {
 924                 return MWNamespace::hasSubpages( $this->mNamespace )
 925                         ? strpos( $this->getText(), '/' ) !== false
 926                         : false;
 927         }
 928
 929         /**
 930          * Is this a conversion table for the LanguageConverter?
 931          *
 932          * @return Bool
 933          */
 934         public function isConversionTable() {
 935                 return $this->getNamespace() == NS_MEDIAWIKI &&
 936                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
 937         }
 938
 939         /**
 940          * Does that page contain wikitext, or it is JS, CSS or whatever?
 941          *
 942          * @return Bool
 943          */
 944         public function isWikitextPage() {
 945                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 946         }
 947
 948         /**
 949          * Could this page contain custom CSS or JavaScript for the global UI.
 950          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 951          * or CONTENT_MODEL_JAVASCRIPT.
 952          *
 953          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
 954          *
 955          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 956          *
 957          * @return Bool
 958          */
 959         public function isCssOrJsPage() {
 960                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 961                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 962                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 963
 964                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 965                 #      hook funktions can force this method to return true even outside the mediawiki namespace.
 966
 967                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
 968
 969                 return $isCssOrJsPage;
 970         }
 971
 972         /**
 973          * Is this a .css or .js subpage of a user page?
 974          * @return Bool
 975          */
 976         public function isCssJsSubpage() {
 977                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
 978                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 979                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
 980         }
 981
 982         /**
 983          * Trim down a .css or .js subpage title to get the corresponding skin name
 984          *
 985          * @return string containing skin name from .css or .js subpage title
 986          */
 987         public function getSkinFromCssJsSubpage() {
 988                 $subpage = explode( '/', $this->mTextform );
 989                 $subpage = $subpage[ count( $subpage ) - 1 ];
 990                 $lastdot = strrpos( $subpage, '.' );
 991                 if ( $lastdot === false )
 992                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 993                 return substr( $subpage, 0, $lastdot );
 994         }
 995
 996         /**
 997          * Is this a .css subpage of a user page?
 998          *
 999          * @return Bool
1000          */
1001         public function isCssSubpage() {
1002                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1003                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1004         }
1005
1006         /**
1007          * Is this a .js subpage of a user page?
1008          *
1009          * @return Bool
1010          */
1011         public function isJsSubpage() {
1012                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1013                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1014         }
1015
1016         /**
1017          * Is this a talk page of some sort?
1018          *
1019          * @return Bool
1020          */
1021         public function isTalkPage() {
1022                 return MWNamespace::isTalk( $this->getNamespace() );
1023         }
1024
1025         /**
1026          * Get a Title object associated with the talk page of this article
1027          *
1028          * @return Title the object for the talk page
1029          */
1030         public function getTalkPage() {
1031                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1032         }
1033
1034         /**
1035          * Get a title object associated with the subject page of this
1036          * talk page
1037          *
1038          * @return Title the object for the subject page
1039          */
1040         public function getSubjectPage() {
1041                 // Is this the same title?
1042                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1043                 if ( $this->getNamespace() == $subjectNS ) {
1044                         return $this;
1045                 }
1046                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1047         }
1048
1049         /**
1050          * Get the default namespace index, for when there is no namespace
1051          *
1052          * @return Int Default namespace index
1053          */
1054         public function getDefaultNamespace() {
1055                 return $this->mDefaultNamespace;
1056         }
1057
1058         /**
1059          * Get title for search index
1060          *
1061          * @return String a stripped-down title string ready for the
1062          *  search index
1063          */
1064         public function getIndexTitle() {
1065                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1066         }
1067
1068         /**
1069          * Get the Title fragment (i.e.\ the bit after the #) in text form
1070          *
1071          * @return String Title fragment
1072          */
1073         public function getFragment() {
1074                 return $this->mFragment;
1075         }
1076
1077         /**
1078          * Get the fragment in URL form, including the "#" character if there is one
1079          * @return String Fragment in URL form
1080          */
1081         public function getFragmentForURL() {
1082                 if ( $this->mFragment == '' ) {
1083                         return '';
1084                 } else {
1085                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1086                 }
1087         }
1088
1089         /**
1090          * Set the fragment for this title. Removes the first character from the
1091          * specified fragment before setting, so it assumes you're passing it with
1092          * an initial "#".
1093          *
1094          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1095          * Still in active use privately.
1096          *
1097          * @param $fragment String text
1098          */
1099         public function setFragment( $fragment ) {
1100                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1101         }
1102
1103         /**
1104          * Prefix some arbitrary text with the namespace or interwiki prefix
1105          * of this object
1106          *
1107          * @param $name String the text
1108          * @return String the prefixed text
1109          * @private
1110          */
1111         private function prefix( $name ) {
1112                 $p = '';
1113                 if ( $this->mInterwiki != '' ) {
1114                         $p = $this->mInterwiki . ':';
1115                 }
1116
1117                 if ( 0 != $this->mNamespace ) {
1118                         $p .= $this->getNsText() . ':';
1119                 }
1120                 return $p . $name;
1121         }
1122
1123         /**
1124          * Get the prefixed database key form
1125          *
1126          * @return String the prefixed title, with underscores and
1127          *  any interwiki and namespace prefixes
1128          */
1129         public function getPrefixedDBkey() {
1130                 $s = $this->prefix( $this->mDbkeyform );
1131                 $s = str_replace( ' ', '_', $s );
1132                 return $s;
1133         }
1134
1135         /**
1136          * Get the prefixed title with spaces.
1137          * This is the form usually used for display
1138          *
1139          * @return String the prefixed title, with spaces
1140          */
1141         public function getPrefixedText() {
1142                 // @todo FIXME: Bad usage of empty() ?
1143                 if ( empty( $this->mPrefixedText ) ) {
1144                         $s = $this->prefix( $this->mTextform );
1145                         $s = str_replace( '_', ' ', $s );
1146                         $this->mPrefixedText = $s;
1147                 }
1148                 return $this->mPrefixedText;
1149         }
1150
1151         /**
1152          * Return a string representation of this title
1153          *
1154          * @return String representation of this title
1155          */
1156         public function __toString() {
1157                 return $this->getPrefixedText();
1158         }
1159
1160         /**
1161          * Get the prefixed title with spaces, plus any fragment
1162          * (part beginning with '#')
1163          *
1164          * @return String the prefixed title, with spaces and the fragment, including '#'
1165          */
1166         public function getFullText() {
1167                 $text = $this->getPrefixedText();
1168                 if ( $this->mFragment != '' ) {
1169                         $text .= '#' . $this->mFragment;
1170                 }
1171                 return $text;
1172         }
1173
1174         /**
1175          * Get the base page name, i.e. the leftmost part before any slashes
1176          *
1177          * @return String Base name
1178          */
1179         public function getBaseText() {
1180                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1181                         return $this->getText();
1182                 }
1183
1184                 $parts = explode( '/', $this->getText() );
1185                 # Don't discard the real title if there's no subpage involved
1186                 if ( count( $parts ) > 1 ) {
1187                         unset( $parts[count( $parts ) - 1] );
1188                 }
1189                 return implode( '/', $parts );
1190         }
1191
1192         /**
1193          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1194          *
1195          * @return String Subpage name
1196          */
1197         public function getSubpageText() {
1198                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1199                         return( $this->mTextform );
1200                 }
1201                 $parts = explode( '/', $this->mTextform );
1202                 return( $parts[count( $parts ) - 1] );
1203         }
1204
1205         /**
1206          * Get the HTML-escaped displayable text form.
1207          * Used for the title field in <a> tags.
1208          *
1209          * @return String the text, including any prefixes
1210          */
1211         public function getEscapedText() {
1212                 wfDeprecated( __METHOD__, '1.19' );
1213                 return htmlspecialchars( $this->getPrefixedText() );
1214         }
1215
1216         /**
1217          * Get a URL-encoded form of the subpage text
1218          *
1219          * @return String URL-encoded subpage name
1220          */
1221         public function getSubpageUrlForm() {
1222                 $text = $this->getSubpageText();
1223                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1224                 return( $text );
1225         }
1226
1227         /**
1228          * Get a URL-encoded title (not an actual URL) including interwiki
1229          *
1230          * @return String the URL-encoded form
1231          */
1232         public function getPrefixedURL() {
1233                 $s = $this->prefix( $this->mDbkeyform );
1234                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1235                 return $s;
1236         }
1237
1238         /**
1239          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1240          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1241          * second argument named variant. This was deprecated in favor
1242          * of passing an array of option with a "variant" key
1243          * Once $query2 is removed for good, this helper can be dropped
1244          * andthe wfArrayToCGI moved to getLocalURL();
1245          *
1246          * @since 1.19 (r105919)
1247          * @param $query
1248          * @param $query2 bool
1249          * @return String
1250          */
1251         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1252                 if( $query2 !== false ) {
1253                         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" );
1254                 }
1255                 if ( is_array( $query ) ) {
1256                         $query = wfArrayToCGI( $query );
1257                 }
1258                 if ( $query2 ) {
1259                         if ( is_string( $query2 ) ) {
1260                                 // $query2 is a string, we will consider this to be
1261                                 // a deprecated $variant argument and add it to the query
1262                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1263                         } else {
1264                                 $query2 = wfArrayToCGI( $query2 );
1265                         }
1266                         // If we have $query content add a & to it first
1267                         if ( $query ) {
1268                                 $query .= '&';
1269                         }
1270                         // Now append the queries together
1271                         $query .= $query2;
1272                 }
1273                 return $query;
1274         }
1275
1276         /**
1277          * Get a real URL referring to this title, with interwiki link and
1278          * fragment
1279          *
1280          * See getLocalURL for the arguments.
1281          *
1282          * @see self::getLocalURL
1283          * @return String the URL
1284          */
1285         public function getFullURL( $query = '', $query2 = false ) {
1286                 $query = self::fixUrlQueryArgs( $query, $query2 );
1287
1288                 # Hand off all the decisions on urls to getLocalURL
1289                 $url = $this->getLocalURL( $query );
1290
1291                 # Expand the url to make it a full url. Note that getLocalURL has the
1292                 # potential to output full urls for a variety of reasons, so we use
1293                 # wfExpandUrl instead of simply prepending $wgServer
1294                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1295
1296                 # Finally, add the fragment.
1297                 $url .= $this->getFragmentForURL();
1298
1299                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1300                 return $url;
1301         }
1302
1303         /**
1304          * Get a URL with no fragment or server name.  If this page is generated
1305          * with action=render, $wgServer is prepended.
1306          *
1307
1308          * @param $query string|array an optional query string,
1309          *   not used for interwiki     links. Can be specified as an associative array as well,
1310          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1311          *   Some query patterns will trigger various shorturl path replacements.
1312          * @param $query2 Mixed: An optional secondary query array. This one MUST
1313          *   be an array. If a string is passed it will be interpreted as a deprecated
1314          *   variant argument and urlencoded into a variant= argument.
1315          *   This second query argument will be added to the $query
1316          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1317          *   pair in the first parameter array instead.
1318          *
1319          * @return String the URL
1320          */
1321         public function getLocalURL( $query = '', $query2 = false ) {
1322                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1323
1324                 $query = self::fixUrlQueryArgs( $query, $query2 );
1325
1326                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1327                 if ( $interwiki ) {
1328                         $namespace = $this->getNsText();
1329                         if ( $namespace != '' ) {
1330                                 # Can this actually happen? Interwikis shouldn't be parsed.
1331                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1332                                 $namespace .= ':';
1333                         }
1334                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1335                         $url = wfAppendQuery( $url, $query );
1336                 } else {
1337                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1338                         if ( $query == '' ) {
1339                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1340                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1341                         } else {
1342                                 global $wgVariantArticlePath, $wgActionPaths;
1343                                 $url = false;
1344                                 $matches = array();
1345
1346                                 if ( !empty( $wgActionPaths ) &&
1347                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1348                                 {
1349                                         $action = urldecode( $matches[2] );
1350                                         if ( isset( $wgActionPaths[$action] ) ) {
1351                                                 $query = $matches[1];
1352                                                 if ( isset( $matches[4] ) ) {
1353                                                         $query .= $matches[4];
1354                                                 }
1355                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1356                                                 if ( $query != '' ) {
1357                                                         $url = wfAppendQuery( $url, $query );
1358                                                 }
1359                                         }
1360                                 }
1361
1362                                 if ( $url === false &&
1363                                         $wgVariantArticlePath &&
1364                                         $this->getPageLanguage()->hasVariants() &&
1365                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1366                                 {
1367                                         $variant = urldecode( $matches[1] );
1368                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1369                                                 // Only do the variant replacement if the given variant is a valid
1370                                                 // variant for the page's language.
1371                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1372                                                 $url = str_replace( '$1', $dbkey, $url );
1373                                         }
1374                                 }
1375
1376                                 if ( $url === false ) {
1377                                         if ( $query == '-' ) {
1378                                                 $query = '';
1379                                         }
1380                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1381                                 }
1382                         }
1383
1384                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1385
1386                         // @todo FIXME: This causes breakage in various places when we
1387                         // actually expected a local URL and end up with dupe prefixes.
1388                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1389                                 $url = $wgServer . $url;
1390                         }
1391                 }
1392                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1393                 return $url;
1394         }
1395
1396         /**
1397          * Get a URL that's the simplest URL that will be valid to link, locally,
1398          * to the current Title.  It includes the fragment, but does not include
1399          * the server unless action=render is used (or the link is external).  If
1400          * there's a fragment but the prefixed text is empty, we just return a link
1401          * to the fragment.
1402          *
1403          * The result obviously should not be URL-escaped, but does need to be
1404          * HTML-escaped if it's being output in HTML.
1405          *
1406          * See getLocalURL for the arguments.
1407          *
1408          * @see self::getLocalURL
1409          * @return String the URL
1410          */
1411         public function getLinkURL( $query = '', $query2 = false ) {
1412                 wfProfileIn( __METHOD__ );
1413                 if ( $this->isExternal() ) {
1414                         $ret = $this->getFullURL( $query, $query2 );
1415                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1416                         $ret = $this->getFragmentForURL();
1417                 } else {
1418                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1419                 }
1420                 wfProfileOut( __METHOD__ );
1421                 return $ret;
1422         }
1423
1424         /**
1425          * Get an HTML-escaped version of the URL form, suitable for
1426          * using in a link, without a server name or fragment
1427          *
1428          * See getLocalURL for the arguments.
1429          *
1430          * @see self::getLocalURL
1431          * @param $query string
1432          * @param $query2 bool|string
1433          * @return String the URL
1434          */
1435         public function escapeLocalURL( $query = '', $query2 = false ) {
1436                 wfDeprecated( __METHOD__, '1.19' );
1437                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1438         }
1439
1440         /**
1441          * Get an HTML-escaped version of the URL form, suitable for
1442          * using in a link, including the server name and fragment
1443          *
1444          * See getLocalURL for the arguments.
1445          *
1446          * @see self::getLocalURL
1447          * @return String the URL
1448          */
1449         public function escapeFullURL( $query = '', $query2 = false ) {
1450                 wfDeprecated( __METHOD__, '1.19' );
1451                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1452         }
1453
1454         /**
1455          * Get the URL form for an internal link.
1456          * - Used in various Squid-related code, in case we have a different
1457          * internal hostname for the server from the exposed one.
1458          *
1459          * This uses $wgInternalServer to qualify the path, or $wgServer
1460          * if $wgInternalServer is not set. If the server variable used is
1461          * protocol-relative, the URL will be expanded to http://
1462          *
1463          * See getLocalURL for the arguments.
1464          *
1465          * @see self::getLocalURL
1466          * @return String the URL
1467          */
1468         public function getInternalURL( $query = '', $query2 = false ) {
1469                 global $wgInternalServer, $wgServer;
1470                 $query = self::fixUrlQueryArgs( $query, $query2 );
1471                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1472                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1473                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1474                 return $url;
1475         }
1476
1477         /**
1478          * Get the URL for a canonical link, for use in things like IRC and
1479          * e-mail notifications. Uses $wgCanonicalServer and the
1480          * GetCanonicalURL hook.
1481          *
1482          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1483          *
1484          * See getLocalURL for the arguments.
1485          *
1486          * @see self::getLocalURL
1487          * @return string The URL
1488          * @since 1.18
1489          */
1490         public function getCanonicalURL( $query = '', $query2 = false ) {
1491                 $query = self::fixUrlQueryArgs( $query, $query2 );
1492                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1493                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1494                 return $url;
1495         }
1496
1497         /**
1498          * HTML-escaped version of getCanonicalURL()
1499          *
1500          * See getLocalURL for the arguments.
1501          *
1502          * @see self::getLocalURL
1503          * @since 1.18
1504          * @return string
1505          */
1506         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1507                 wfDeprecated( __METHOD__, '1.19' );
1508                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1509         }
1510
1511         /**
1512          * Get the edit URL for this Title
1513          *
1514          * @return String the URL, or a null string if this is an
1515          *  interwiki link
1516          */
1517         public function getEditURL() {
1518                 if ( $this->mInterwiki != '' ) {
1519                         return '';
1520                 }
1521                 $s = $this->getLocalURL( 'action=edit' );
1522
1523                 return $s;
1524         }
1525
1526         /**
1527          * Is $wgUser watching this page?
1528          *
1529          * @deprecated in 1.20; use User::isWatched() instead.
1530          * @return Bool
1531          */
1532         public function userIsWatching() {
1533                 global $wgUser;
1534
1535                 if ( is_null( $this->mWatched ) ) {
1536                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1537                                 $this->mWatched = false;
1538                         } else {
1539                                 $this->mWatched = $wgUser->isWatched( $this );
1540                         }
1541                 }
1542                 return $this->mWatched;
1543         }
1544
1545         /**
1546          * Can $wgUser read this page?
1547          *
1548          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1549          * @return Bool
1550          * @todo fold these checks into userCan()
1551          */
1552         public function userCanRead() {
1553                 wfDeprecated( __METHOD__, '1.19' );
1554                 return $this->userCan( 'read' );
1555         }
1556
1557         /**
1558          * Can $user perform $action on this page?
1559          * This skips potentially expensive cascading permission checks
1560          * as well as avoids expensive error formatting
1561          *
1562          * Suitable for use for nonessential UI controls in common cases, but
1563          * _not_ for functional access control.
1564          *
1565          * May provide false positives, but should never provide a false negative.
1566          *
1567          * @param $action String action that permission needs to be checked for
1568          * @param $user User to check (since 1.19); $wgUser will be used if not
1569          *              provided.
1570          * @return Bool
1571          */
1572         public function quickUserCan( $action, $user = null ) {
1573                 return $this->userCan( $action, $user, false );
1574         }
1575
1576         /**
1577          * Can $user perform $action on this page?
1578          *
1579          * @param $action String action that permission needs to be checked for
1580          * @param $user User to check (since 1.19); $wgUser will be used if not
1581          *   provided.
1582          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1583          *   unnecessary queries.
1584          * @return Bool
1585          */
1586         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1587                 if ( !$user instanceof User ) {
1588                         global $wgUser;
1589                         $user = $wgUser;
1590                 }
1591                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1592         }
1593
1594         /**
1595          * Can $user perform $action on this page?
1596          *
1597          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1598          *
1599          * @param $action String action that permission needs to be checked for
1600          * @param $user User to check
1601          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1602          *   queries by skipping checks for cascading protections and user blocks.
1603          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1604          *   whose corresponding errors may be ignored.
1605          * @return Array of arguments to wfMsg to explain permissions problems.
1606          */
1607         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1608                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1609
1610                 // Remove the errors being ignored.
1611                 foreach ( $errors as $index => $error ) {
1612                         $error_key = is_array( $error ) ? $error[0] : $error;
1613
1614                         if ( in_array( $error_key, $ignoreErrors ) ) {
1615                                 unset( $errors[$index] );
1616                         }
1617                 }
1618
1619                 return $errors;
1620         }
1621
1622         /**
1623          * Permissions checks that fail most often, and which are easiest to test.
1624          *
1625          * @param $action String the action to check
1626          * @param $user User user to check
1627          * @param $errors Array list of current errors
1628          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1629          * @param $short Boolean short circuit on first error
1630          *
1631          * @return Array list of errors
1632          */
1633         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1634                 if ( $action == 'create' ) {
1635                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1636                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1637                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1638                         }
1639                 } elseif ( $action == 'move' ) {
1640                         if ( !$user->isAllowed( 'move-rootuserpages' )
1641                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1642                                 // Show user page-specific message only if the user can move other pages
1643                                 $errors[] = array( 'cant-move-user-page' );
1644                         }
1645
1646                         // Check if user is allowed to move files if it's a file
1647                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1648                                 $errors[] = array( 'movenotallowedfile' );
1649                         }
1650
1651                         if ( !$user->isAllowed( 'move' ) ) {
1652                                 // User can't move anything
1653                                 global $wgGroupPermissions;
1654                                 $userCanMove = false;
1655                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1656                                         $userCanMove = $wgGroupPermissions['user']['move'];
1657                                 }
1658                                 $autoconfirmedCanMove = false;
1659                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1660                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1661                                 }
1662                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1663                                         // custom message if logged-in users without any special rights can move
1664                                         $errors[] = array( 'movenologintext' );
1665                                 } else {
1666                                         $errors[] = array( 'movenotallowed' );
1667                                 }
1668                         }
1669                 } elseif ( $action == 'move-target' ) {
1670                         if ( !$user->isAllowed( 'move' ) ) {
1671                                 // User can't move anything
1672                                 $errors[] = array( 'movenotallowed' );
1673                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1674                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1675                                 // Show user page-specific message only if the user can move other pages
1676                                 $errors[] = array( 'cant-move-to-user-page' );
1677                         }
1678                 } elseif ( !$user->isAllowed( $action ) ) {
1679                         $errors[] = $this->missingPermissionError( $action, $short );
1680                 }
1681
1682                 return $errors;
1683         }
1684
1685         /**
1686          * Add the resulting error code to the errors array
1687          *
1688          * @param $errors Array list of current errors
1689          * @param $result Mixed result of errors
1690          *
1691          * @return Array list of errors
1692          */
1693         private function resultToError( $errors, $result ) {
1694                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1695                         // A single array representing an error
1696                         $errors[] = $result;
1697                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1698                         // A nested array representing multiple errors
1699                         $errors = array_merge( $errors, $result );
1700                 } elseif ( $result !== '' && is_string( $result ) ) {
1701                         // A string representing a message-id
1702                         $errors[] = array( $result );
1703                 } elseif ( $result === false ) {
1704                         // a generic "We don't want them to do that"
1705                         $errors[] = array( 'badaccess-group0' );
1706                 }
1707                 return $errors;
1708         }
1709
1710         /**
1711          * Check various permission hooks
1712          *
1713          * @param $action String the action to check
1714          * @param $user User user to check
1715          * @param $errors Array list of current errors
1716          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1717          * @param $short Boolean short circuit on first error
1718          *
1719          * @return Array list of errors
1720          */
1721         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1722                 // Use getUserPermissionsErrors instead
1723                 $result = '';
1724                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1725                         return $result ? array() : array( array( 'badaccess-group0' ) );
1726                 }
1727                 // Check getUserPermissionsErrors hook
1728                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1729                         $errors = $this->resultToError( $errors, $result );
1730                 }
1731                 // Check getUserPermissionsErrorsExpensive hook
1732                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1733                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1734                         $errors = $this->resultToError( $errors, $result );
1735                 }
1736
1737                 return $errors;
1738         }
1739
1740         /**
1741          * Check permissions on special pages & namespaces
1742          *
1743          * @param $action String the action to check
1744          * @param $user User user to check
1745          * @param $errors Array list of current errors
1746          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1747          * @param $short Boolean short circuit on first error
1748          *
1749          * @return Array list of errors
1750          */
1751         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1752                 # Only 'createaccount' and 'execute' can be performed on
1753                 # special pages, which don't actually exist in the DB.
1754                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1755                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1756                         $errors[] = array( 'ns-specialprotected' );
1757                 }
1758
1759                 # Check $wgNamespaceProtection for restricted namespaces
1760                 if ( $this->isNamespaceProtected( $user ) ) {
1761                         $ns = $this->mNamespace == NS_MAIN ?
1762                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1763                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1764                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1765                 }
1766
1767                 return $errors;
1768         }
1769
1770         /**
1771          * Check CSS/JS sub-page permissions
1772          *
1773          * @param $action String the action to check
1774          * @param $user User user to check
1775          * @param $errors Array list of current errors
1776          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1777          * @param $short Boolean short circuit on first error
1778          *
1779          * @return Array list of errors
1780          */
1781         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1782                 # Protect css/js subpages of user pages
1783                 # XXX: this might be better using restrictions
1784                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1785                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1786                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1787                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1788                                 $errors[] = array( 'customcssprotected' );
1789                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1790                                 $errors[] = array( 'customjsprotected' );
1791                         }
1792                 }
1793
1794                 return $errors;
1795         }
1796
1797         /**
1798          * Check against page_restrictions table requirements on this
1799          * page. The user must possess all required rights for this
1800          * action.
1801          *
1802          * @param $action String the action to check
1803          * @param $user User user to check
1804          * @param $errors Array list of current errors
1805          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1806          * @param $short Boolean short circuit on first error
1807          *
1808          * @return Array list of errors
1809          */
1810         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1811                 foreach ( $this->getRestrictions( $action ) as $right ) {
1812                         // Backwards compatibility, rewrite sysop -> protect
1813                         if ( $right == 'sysop' ) {
1814                                 $right = 'protect';
1815                         }
1816                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1817                                 // Users with 'editprotected' permission can edit protected pages
1818                                 // without cascading option turned on.
1819                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1820                                         || $this->mCascadeRestriction )
1821                                 {
1822                                         $errors[] = array( 'protectedpagetext', $right );
1823                                 }
1824                         }
1825                 }
1826
1827                 return $errors;
1828         }
1829
1830         /**
1831          * Check restrictions on cascading pages.
1832          *
1833          * @param $action String the action to check
1834          * @param $user User to check
1835          * @param $errors Array list of current errors
1836          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1837          * @param $short Boolean short circuit on first error
1838          *
1839          * @return Array list of errors
1840          */
1841         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1842                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1843                         # We /could/ use the protection level on the source page, but it's
1844                         # fairly ugly as we have to establish a precedence hierarchy for pages
1845                         # included by multiple cascade-protected pages. So just restrict
1846                         # it to people with 'protect' permission, as they could remove the
1847                         # protection anyway.
1848                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1849                         # Cascading protection depends on more than this page...
1850                         # Several cascading protected pages may include this page...
1851                         # Check each cascading level
1852                         # This is only for protection restrictions, not for all actions
1853                         if ( isset( $restrictions[$action] ) ) {
1854                                 foreach ( $restrictions[$action] as $right ) {
1855                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1856                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1857                                                 $pages = '';
1858                                                 foreach ( $cascadingSources as $page )
1859                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1860                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1861                                         }
1862                                 }
1863                         }
1864                 }
1865
1866                 return $errors;
1867         }
1868
1869         /**
1870          * Check action permissions not already checked in checkQuickPermissions
1871          *
1872          * @param $action String the action to check
1873          * @param $user User to check
1874          * @param $errors Array list of current errors
1875          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1876          * @param $short Boolean short circuit on first error
1877          *
1878          * @return Array list of errors
1879          */
1880         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1881                 global $wgDeleteRevisionsLimit, $wgLang;
1882
1883                 if ( $action == 'protect' ) {
1884                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1885                                 // If they can't edit, they shouldn't protect.
1886                                 $errors[] = array( 'protect-cantedit' );
1887                         }
1888                 } elseif ( $action == 'create' ) {
1889                         $title_protection = $this->getTitleProtection();
1890                         if( $title_protection ) {
1891                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1892                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1893                                 }
1894                                 if( $title_protection['pt_create_perm'] == '' ||
1895                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1896                                 {
1897                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1898                                 }
1899                         }
1900                 } elseif ( $action == 'move' ) {
1901                         // Check for immobile pages
1902                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1903                                 // Specific message for this case
1904                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1905                         } elseif ( !$this->isMovable() ) {
1906                                 // Less specific message for rarer cases
1907                                 $errors[] = array( 'immobile-source-page' );
1908                         }
1909                 } elseif ( $action == 'move-target' ) {
1910                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1911                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1912                         } elseif ( !$this->isMovable() ) {
1913                                 $errors[] = array( 'immobile-target-page' );
1914                         }
1915                 } elseif ( $action == 'delete' ) {
1916                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1917                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1918                         {
1919                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1920                         }
1921                 }
1922                 return $errors;
1923         }
1924
1925         /**
1926          * Check that the user isn't blocked from editting.
1927          *
1928          * @param $action String the action to check
1929          * @param $user User to check
1930          * @param $errors Array list of current errors
1931          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1932          * @param $short Boolean short circuit on first error
1933          *
1934          * @return Array list of errors
1935          */
1936         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1937                 // Account creation blocks handled at userlogin.
1938                 // Unblocking handled in SpecialUnblock
1939                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1940                         return $errors;
1941                 }
1942
1943                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1944
1945                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1946                         $errors[] = array( 'confirmedittext' );
1947                 }
1948
1949                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1950                         // Don't block the user from editing their own talk page unless they've been
1951                         // explicitly blocked from that too.
1952                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1953                         $block = $user->getBlock();
1954
1955                         // This is from OutputPage::blockedPage
1956                         // Copied at r23888 by werdna
1957
1958                         $id = $user->blockedBy();
1959                         $reason = $user->blockedFor();
1960                         if ( $reason == '' ) {
1961                                 $reason = wfMsg( 'blockednoreason' );
1962                         }
1963                         $ip = $user->getRequest()->getIP();
1964
1965                         if ( is_numeric( $id ) ) {
1966                                 $name = User::whoIs( $id );
1967                         } else {
1968                                 $name = $id;
1969                         }
1970
1971                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1972                         $blockid = $block->getId();
1973                         $blockExpiry = $block->getExpiry();
1974                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
1975                         if ( $blockExpiry == 'infinity' ) {
1976                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1977                         } else {
1978                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1979                         }
1980
1981                         $intended = strval( $block->getTarget() );
1982
1983                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1984                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1985                 }
1986
1987                 return $errors;
1988         }
1989
1990         /**
1991          * Check that the user is allowed to read this page.
1992          *
1993          * @param $action String the action to check
1994          * @param $user User to check
1995          * @param $errors Array list of current errors
1996          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1997          * @param $short Boolean short circuit on first error
1998          *
1999          * @return Array list of errors
2000          */
2001         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2002                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
2003                 static $useShortcut = null;
2004
2005                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2006                 if ( is_null( $useShortcut ) ) {
2007                         $useShortcut = true;
2008                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
2009                                 # Not a public wiki, so no shortcut
2010                                 $useShortcut = false;
2011                         } elseif ( !empty( $wgRevokePermissions ) ) {
2012                                 /**
2013                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2014                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2015                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2016                                  * reading is allowed.
2017                                  */
2018                                 foreach ( $wgRevokePermissions as $perms ) {
2019                                         if ( !empty( $perms['read'] ) ) {
2020                                                 # We might be removing the read right from the user, so no shortcut
2021                                                 $useShortcut = false;
2022                                                 break;
2023                                         }
2024                                 }
2025                         }
2026                 }
2027
2028                 $whitelisted = false;
2029                 if ( $useShortcut ) {
2030                         # Shortcut for public wikis, allows skipping quite a bit of code
2031                         $whitelisted = true;
2032                 } elseif ( $user->isAllowed( 'read' ) ) {
2033                         # If the user is allowed to read pages, he is allowed to read all pages
2034                         $whitelisted = true;
2035                 } elseif ( $this->isSpecial( 'Userlogin' )
2036                         || $this->isSpecial( 'ChangePassword' )
2037                         || $this->isSpecial( 'PasswordReset' )
2038                 ) {
2039                         # Always grant access to the login page.
2040                         # Even anons need to be able to log in.
2041                         $whitelisted = true;
2042                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2043                         # Time to check the whitelist
2044                         # Only do these checks is there's something to check against
2045                         $name = $this->getPrefixedText();
2046                         $dbName = $this->getPrefixedDBKey();
2047
2048                         // Check for explicit whitelisting with and without underscores
2049                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2050                                 $whitelisted = true;
2051                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2052                                 # Old settings might have the title prefixed with
2053                                 # a colon for main-namespace pages
2054                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2055                                         $whitelisted = true;
2056                                 }
2057                         } elseif ( $this->isSpecialPage() ) {
2058                                 # If it's a special page, ditch the subpage bit and check again
2059                                 $name = $this->getDBkey();
2060                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2061                                 if ( $name !== false ) {
2062                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2063                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2064                                                 $whitelisted = true;
2065                                         }
2066                                 }
2067                         }
2068                 }
2069
2070                 if ( !$whitelisted ) {
2071                         # If the title is not whitelisted, give extensions a chance to do so...
2072                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2073                         if ( !$whitelisted ) {
2074                                 $errors[] = $this->missingPermissionError( $action, $short );
2075                         }
2076                 }
2077
2078                 return $errors;
2079         }
2080
2081         /**
2082          * Get a description array when the user doesn't have the right to perform
2083          * $action (i.e. when User::isAllowed() returns false)
2084          *
2085          * @param $action String the action to check
2086          * @param $short Boolean short circuit on first error
2087          * @return Array list of errors
2088          */
2089         private function missingPermissionError( $action, $short ) {
2090                 // We avoid expensive display logic for quickUserCan's and such
2091                 if ( $short ) {
2092                         return array( 'badaccess-group0' );
2093                 }
2094
2095                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2096                         User::getGroupsWithPermission( $action ) );
2097
2098                 if ( count( $groups ) ) {
2099                         global $wgLang;
2100                         return array(
2101                                 'badaccess-groups',
2102                                 $wgLang->commaList( $groups ),
2103                                 count( $groups )
2104                         );
2105                 } else {
2106                         return array( 'badaccess-group0' );
2107                 }
2108         }
2109
2110         /**
2111          * Can $user perform $action on this page? This is an internal function,
2112          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2113          * checks on wfReadOnly() and blocks)
2114          *
2115          * @param $action String action that permission needs to be checked for
2116          * @param $user User to check
2117          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2118          * @param $short Bool Set this to true to stop after the first permission error.
2119          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2120          */
2121         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2122                 wfProfileIn( __METHOD__ );
2123
2124                 # Read has special handling
2125                 if ( $action == 'read' ) {
2126                         $checks = array(
2127                                 'checkPermissionHooks',
2128                                 'checkReadPermissions',
2129                         );
2130                 } else {
2131                         $checks = array(
2132                                 'checkQuickPermissions',
2133                                 'checkPermissionHooks',
2134                                 'checkSpecialsAndNSPermissions',
2135                                 'checkCSSandJSPermissions',
2136                                 'checkPageRestrictions',
2137                                 'checkCascadingSourcesRestrictions',
2138                                 'checkActionPermissions',
2139                                 'checkUserBlock'
2140                         );
2141                 }
2142
2143                 $errors = array();
2144                 while( count( $checks ) > 0 &&
2145                                 !( $short && count( $errors ) > 0 ) ) {
2146                         $method = array_shift( $checks );
2147                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2148                 }
2149
2150                 wfProfileOut( __METHOD__ );
2151                 return $errors;
2152         }
2153
2154         /**
2155          * Protect css subpages of user pages: can $wgUser edit
2156          * this page?
2157          *
2158          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2159          * @return Bool
2160          */
2161         public function userCanEditCssSubpage() {
2162                 global $wgUser;
2163                 wfDeprecated( __METHOD__, '1.19' );
2164                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2165                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2166         }
2167
2168         /**
2169          * Protect js subpages of user pages: can $wgUser edit
2170          * this page?
2171          *
2172          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2173          * @return Bool
2174          */
2175         public function userCanEditJsSubpage() {
2176                 global $wgUser;
2177                 wfDeprecated( __METHOD__, '1.19' );
2178                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2179                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2180         }
2181
2182         /**
2183          * Get a filtered list of all restriction types supported by this wiki.
2184          * @param bool $exists True to get all restriction types that apply to
2185          * titles that do exist, False for all restriction types that apply to
2186          * titles that do not exist
2187          * @return array
2188          */
2189         public static function getFilteredRestrictionTypes( $exists = true ) {
2190                 global $wgRestrictionTypes;
2191                 $types = $wgRestrictionTypes;
2192                 if ( $exists ) {
2193                         # Remove the create restriction for existing titles
2194                         $types = array_diff( $types, array( 'create' ) );
2195                 } else {
2196                         # Only the create and upload restrictions apply to non-existing titles
2197                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2198                 }
2199                 return $types;
2200         }
2201
2202         /**
2203          * Returns restriction types for the current Title
2204          *
2205          * @return array applicable restriction types
2206          */
2207         public function getRestrictionTypes() {
2208                 if ( $this->isSpecialPage() ) {
2209                         return array();
2210                 }
2211
2212                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2213
2214                 if ( $this->getNamespace() != NS_FILE ) {
2215                         # Remove the upload restriction for non-file titles
2216                         $types = array_diff( $types, array( 'upload' ) );
2217                 }
2218
2219                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2220
2221                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2222                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2223
2224                 return $types;
2225         }
2226
2227         /**
2228          * Is this title subject to title protection?
2229          * Title protection is the one applied against creation of such title.
2230          *
2231          * @return Mixed An associative array representing any existent title
2232          *   protection, or false if there's none.
2233          */
2234         private function getTitleProtection() {
2235                 // Can't protect pages in special namespaces
2236                 if ( $this->getNamespace() < 0 ) {
2237                         return false;
2238                 }
2239
2240                 // Can't protect pages that exist.
2241                 if ( $this->exists() ) {
2242                         return false;
2243                 }
2244
2245                 if ( !isset( $this->mTitleProtection ) ) {
2246                         $dbr = wfGetDB( DB_SLAVE );
2247                         $res = $dbr->select( 'protected_titles', '*',
2248                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2249                                 __METHOD__ );
2250
2251                         // fetchRow returns false if there are no rows.
2252                         $this->mTitleProtection = $dbr->fetchRow( $res );
2253                 }
2254                 return $this->mTitleProtection;
2255         }
2256
2257         /**
2258          * Update the title protection status
2259          *
2260          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2261          * @param $create_perm String Permission required for creation
2262          * @param $reason String Reason for protection
2263          * @param $expiry String Expiry timestamp
2264          * @return boolean true
2265          */
2266         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2267                 wfDeprecated( __METHOD__, '1.19' );
2268
2269                 global $wgUser;
2270
2271                 $limit = array( 'create' => $create_perm );
2272                 $expiry = array( 'create' => $expiry );
2273
2274                 $page = WikiPage::factory( $this );
2275                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2276
2277                 return $status->isOK();
2278         }
2279
2280         /**
2281          * Remove any title protection due to page existing
2282          */
2283         public function deleteTitleProtection() {
2284                 $dbw = wfGetDB( DB_MASTER );
2285
2286                 $dbw->delete(
2287                         'protected_titles',
2288                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2289                         __METHOD__
2290                 );
2291                 $this->mTitleProtection = false;
2292         }
2293
2294         /**
2295          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2296          *
2297          * @param $action String Action to check (default: edit)
2298          * @return Bool
2299          */
2300         public function isSemiProtected( $action = 'edit' ) {
2301                 if ( $this->exists() ) {
2302                         $restrictions = $this->getRestrictions( $action );
2303                         if ( count( $restrictions ) > 0 ) {
2304                                 foreach ( $restrictions as $restriction ) {
2305                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2306                                                 return false;
2307                                         }
2308                                 }
2309                         } else {
2310                                 # Not protected
2311                                 return false;
2312                         }
2313                         return true;
2314                 } else {
2315                         # If it doesn't exist, it can't be protected
2316                         return false;
2317                 }
2318         }
2319
2320         /**
2321          * Does the title correspond to a protected article?
2322          *
2323          * @param $action String the action the page is protected from,
2324          * by default checks all actions.
2325          * @return Bool
2326          */
2327         public function isProtected( $action = '' ) {
2328                 global $wgRestrictionLevels;
2329
2330                 $restrictionTypes = $this->getRestrictionTypes();
2331
2332                 # Special pages have inherent protection
2333                 if( $this->isSpecialPage() ) {
2334                         return true;
2335                 }
2336
2337                 # Check regular protection levels
2338                 foreach ( $restrictionTypes as $type ) {
2339                         if ( $action == $type || $action == '' ) {
2340                                 $r = $this->getRestrictions( $type );
2341                                 foreach ( $wgRestrictionLevels as $level ) {
2342                                         if ( in_array( $level, $r ) && $level != '' ) {
2343                                                 return true;
2344                                         }
2345                                 }
2346                         }
2347                 }
2348
2349                 return false;
2350         }
2351
2352         /**
2353          * Determines if $user is unable to edit this page because it has been protected
2354          * by $wgNamespaceProtection.
2355          *
2356          * @param $user User object to check permissions
2357          * @return Bool
2358          */
2359         public function isNamespaceProtected( User $user ) {
2360                 global $wgNamespaceProtection;
2361
2362                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2363                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2364                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2365                                         return true;
2366                                 }
2367                         }
2368                 }
2369                 return false;
2370         }
2371
2372         /**
2373          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2374          *
2375          * @return Bool If the page is subject to cascading restrictions.
2376          */
2377         public function isCascadeProtected() {
2378                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2379                 return ( $sources > 0 );
2380         }
2381
2382         /**
2383          * Cascading protection: Get the source of any cascading restrictions on this page.
2384          *
2385          * @param $getPages Bool Whether or not to retrieve the actual pages
2386          *        that the restrictions have come from.
2387          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2388          *     have come, false for none, or true if such restrictions exist, but $getPages
2389          *     was not set.  The restriction array is an array of each type, each of which
2390          *     contains a array of unique groups.
2391          */
2392         public function getCascadeProtectionSources( $getPages = true ) {
2393                 global $wgContLang;
2394                 $pagerestrictions = array();
2395
2396                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2397                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2398                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2399                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2400                 }
2401
2402                 wfProfileIn( __METHOD__ );
2403
2404                 $dbr = wfGetDB( DB_SLAVE );
2405
2406                 if ( $this->getNamespace() == NS_FILE ) {
2407                         $tables = array( 'imagelinks', 'page_restrictions' );
2408                         $where_clauses = array(
2409                                 'il_to' => $this->getDBkey(),
2410                                 'il_from=pr_page',
2411                                 'pr_cascade' => 1
2412                         );
2413                 } else {
2414                         $tables = array( 'templatelinks', 'page_restrictions' );
2415                         $where_clauses = array(
2416                                 'tl_namespace' => $this->getNamespace(),
2417                                 'tl_title' => $this->getDBkey(),
2418                                 'tl_from=pr_page',
2419                                 'pr_cascade' => 1
2420                         );
2421                 }
2422
2423                 if ( $getPages ) {
2424                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2425                                                    'pr_expiry', 'pr_type', 'pr_level' );
2426                         $where_clauses[] = 'page_id=pr_page';
2427                         $tables[] = 'page';
2428                 } else {
2429                         $cols = array( 'pr_expiry' );
2430                 }
2431
2432                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2433
2434                 $sources = $getPages ? array() : false;
2435                 $now = wfTimestampNow();
2436                 $purgeExpired = false;
2437
2438                 foreach ( $res as $row ) {
2439                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2440                         if ( $expiry > $now ) {
2441                                 if ( $getPages ) {
2442                                         $page_id = $row->pr_page;
2443                                         $page_ns = $row->page_namespace;
2444                                         $page_title = $row->page_title;
2445                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2446                                         # Add groups needed for each restriction type if its not already there
2447                                         # Make sure this restriction type still exists
2448
2449                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2450                                                 $pagerestrictions[$row->pr_type] = array();
2451                                         }
2452
2453                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2454                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2455                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2456                                         }
2457                                 } else {
2458                                         $sources = true;
2459                                 }
2460                         } else {
2461                                 // Trigger lazy purge of expired restrictions from the db
2462                                 $purgeExpired = true;
2463                         }
2464                 }
2465                 if ( $purgeExpired ) {
2466                         Title::purgeExpiredRestrictions();
2467                 }
2468
2469                 if ( $getPages ) {
2470                         $this->mCascadeSources = $sources;
2471                         $this->mCascadingRestrictions = $pagerestrictions;
2472                 } else {
2473                         $this->mHasCascadingRestrictions = $sources;
2474                 }
2475
2476                 wfProfileOut( __METHOD__ );
2477                 return array( $sources, $pagerestrictions );
2478         }
2479
2480         /**
2481          * Accessor/initialisation for mRestrictions
2482          *
2483          * @param $action String action that permission needs to be checked for
2484          * @return Array of Strings the array of groups allowed to edit this article
2485          */
2486         public function getRestrictions( $action ) {
2487                 if ( !$this->mRestrictionsLoaded ) {
2488                         $this->loadRestrictions();
2489                 }
2490                 return isset( $this->mRestrictions[$action] )
2491                                 ? $this->mRestrictions[$action]
2492                                 : array();
2493         }
2494
2495         /**
2496          * Get the expiry time for the restriction against a given action
2497          *
2498          * @param $action
2499          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2500          *     or not protected at all, or false if the action is not recognised.
2501          */
2502         public function getRestrictionExpiry( $action ) {
2503                 if ( !$this->mRestrictionsLoaded ) {
2504                         $this->loadRestrictions();
2505                 }
2506                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2507         }
2508
2509         /**
2510          * Returns cascading restrictions for the current article
2511          *
2512          * @return Boolean
2513          */
2514         function areRestrictionsCascading() {
2515                 if ( !$this->mRestrictionsLoaded ) {
2516                         $this->loadRestrictions();
2517                 }
2518
2519                 return $this->mCascadeRestriction;
2520         }
2521
2522         /**
2523          * Loads a string into mRestrictions array
2524          *
2525          * @param $res Resource restrictions as an SQL result.
2526          * @param $oldFashionedRestrictions String comma-separated list of page
2527          *        restrictions from page table (pre 1.10)
2528          */
2529         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2530                 $rows = array();
2531
2532                 foreach ( $res as $row ) {
2533                         $rows[] = $row;
2534                 }
2535
2536                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2537         }
2538
2539         /**
2540          * Compiles list of active page restrictions from both page table (pre 1.10)
2541          * and page_restrictions table for this existing page.
2542          * Public for usage by LiquidThreads.
2543          *
2544          * @param $rows array of db result objects
2545          * @param $oldFashionedRestrictions string comma-separated list of page
2546          *        restrictions from page table (pre 1.10)
2547          */
2548         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2549                 global $wgContLang;
2550                 $dbr = wfGetDB( DB_SLAVE );
2551
2552                 $restrictionTypes = $this->getRestrictionTypes();
2553
2554                 foreach ( $restrictionTypes as $type ) {
2555                         $this->mRestrictions[$type] = array();
2556                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2557                 }
2558
2559                 $this->mCascadeRestriction = false;
2560
2561                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2562
2563                 if ( $oldFashionedRestrictions === null ) {
2564                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2565                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2566                 }
2567
2568                 if ( $oldFashionedRestrictions != '' ) {
2569
2570                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2571                                 $temp = explode( '=', trim( $restrict ) );
2572                                 if ( count( $temp ) == 1 ) {
2573                                         // old old format should be treated as edit/move restriction
2574                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2575                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2576                                 } else {
2577                                         $restriction = trim( $temp[1] );
2578                                         if( $restriction != '' ) { //some old entries are empty
2579                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2580                                         }
2581                                 }
2582                         }
2583
2584                         $this->mOldRestrictions = true;
2585
2586                 }
2587
2588                 if ( count( $rows ) ) {
2589                         # Current system - load second to make them override.
2590                         $now = wfTimestampNow();
2591                         $purgeExpired = false;
2592
2593                         # Cycle through all the restrictions.
2594                         foreach ( $rows as $row ) {
2595
2596                                 // Don't take care of restrictions types that aren't allowed
2597                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2598                                         continue;
2599
2600                                 // This code should be refactored, now that it's being used more generally,
2601                                 // But I don't really see any harm in leaving it in Block for now -werdna
2602                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2603
2604                                 // Only apply the restrictions if they haven't expired!
2605                                 if ( !$expiry || $expiry > $now ) {
2606                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2607                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2608
2609                                         $this->mCascadeRestriction |= $row->pr_cascade;
2610                                 } else {
2611                                         // Trigger a lazy purge of expired restrictions
2612                                         $purgeExpired = true;
2613                                 }
2614                         }
2615
2616                         if ( $purgeExpired ) {
2617                                 Title::purgeExpiredRestrictions();
2618                         }
2619                 }
2620
2621                 $this->mRestrictionsLoaded = true;
2622         }
2623
2624         /**
2625          * Load restrictions from the page_restrictions table
2626          *
2627          * @param $oldFashionedRestrictions String comma-separated list of page
2628          *        restrictions from page table (pre 1.10)
2629          */
2630         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2631                 global $wgContLang;
2632                 if ( !$this->mRestrictionsLoaded ) {
2633                         if ( $this->exists() ) {
2634                                 $dbr = wfGetDB( DB_SLAVE );
2635
2636                                 $res = $dbr->select(
2637                                         'page_restrictions',
2638                                         '*',
2639                                         array( 'pr_page' => $this->getArticleID() ),
2640                                         __METHOD__
2641                                 );
2642
2643                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2644                         } else {
2645                                 $title_protection = $this->getTitleProtection();
2646
2647                                 if ( $title_protection ) {
2648                                         $now = wfTimestampNow();
2649                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2650
2651                                         if ( !$expiry || $expiry > $now ) {
2652                                                 // Apply the restrictions
2653                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2654                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2655                                         } else { // Get rid of the old restrictions
2656                                                 Title::purgeExpiredRestrictions();
2657                                                 $this->mTitleProtection = false;
2658                                         }
2659                                 } else {
2660                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2661                                 }
2662                                 $this->mRestrictionsLoaded = true;
2663                         }
2664                 }
2665         }
2666
2667         /**
2668          * Flush the protection cache in this object and force reload from the database.
2669          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2670          */
2671         public function flushRestrictions() {
2672                 $this->mRestrictionsLoaded = false;
2673                 $this->mTitleProtection = null;
2674         }
2675
2676         /**
2677          * Purge expired restrictions from the page_restrictions table
2678          */
2679         static function purgeExpiredRestrictions() {
2680                 $dbw = wfGetDB( DB_MASTER );
2681                 $dbw->delete(
2682                         'page_restrictions',
2683                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2684                         __METHOD__
2685                 );
2686
2687                 $dbw->delete(
2688                         'protected_titles',
2689                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2690                         __METHOD__
2691                 );
2692         }
2693
2694         /**
2695          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2696          *
2697          * @return Bool
2698          */
2699         public function hasSubpages() {
2700                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2701                         # Duh
2702                         return false;
2703                 }
2704
2705                 # We dynamically add a member variable for the purpose of this method
2706                 # alone to cache the result.  There's no point in having it hanging
2707                 # around uninitialized in every Title object; therefore we only add it
2708                 # if needed and don't declare it statically.
2709                 if ( isset( $this->mHasSubpages ) ) {
2710                         return $this->mHasSubpages;
2711                 }
2712
2713                 $subpages = $this->getSubpages( 1 );
2714                 if ( $subpages instanceof TitleArray ) {
2715                         return $this->mHasSubpages = (bool)$subpages->count();
2716                 }
2717                 return $this->mHasSubpages = false;
2718         }
2719
2720         /**
2721          * Get all subpages of this page.
2722          *
2723          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2724          * @return mixed TitleArray, or empty array if this page's namespace
2725          *  doesn't allow subpages
2726          */
2727         public function getSubpages( $limit = -1 ) {
2728                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2729                         return array();
2730                 }
2731
2732                 $dbr = wfGetDB( DB_SLAVE );
2733                 $conds['page_namespace'] = $this->getNamespace();
2734                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2735                 $options = array();
2736                 if ( $limit > -1 ) {
2737                         $options['LIMIT'] = $limit;
2738                 }
2739                 return $this->mSubpages = TitleArray::newFromResult(
2740                         $dbr->select( 'page',
2741                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2742                                 $conds,
2743                                 __METHOD__,
2744                                 $options
2745                         )
2746                 );
2747         }
2748
2749         /**
2750          * Is there a version of this page in the deletion archive?
2751          *
2752          * @return Int the number of archived revisions
2753          */
2754         public function isDeleted() {
2755                 if ( $this->getNamespace() < 0 ) {
2756                         $n = 0;
2757                 } else {
2758                         $dbr = wfGetDB( DB_SLAVE );
2759
2760                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2761                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2762                                 __METHOD__
2763                         );
2764                         if ( $this->getNamespace() == NS_FILE ) {
2765                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2766                                         array( 'fa_name' => $this->getDBkey() ),
2767                                         __METHOD__
2768                                 );
2769                         }
2770                 }
2771                 return (int)$n;
2772         }
2773
2774         /**
2775          * Is there a version of this page in the deletion archive?
2776          *
2777          * @return Boolean
2778          */
2779         public function isDeletedQuick() {
2780                 if ( $this->getNamespace() < 0 ) {
2781                         return false;
2782                 }
2783                 $dbr = wfGetDB( DB_SLAVE );
2784                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2785                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2786                         __METHOD__
2787                 );
2788                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2789                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2790                                 array( 'fa_name' => $this->getDBkey() ),
2791                                 __METHOD__
2792                         );
2793                 }
2794                 return $deleted;
2795         }
2796
2797         /**
2798          * Get the article ID for this Title from the link cache,
2799          * adding it if necessary
2800          *
2801          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2802          *  for update
2803          * @return Int the ID
2804          */
2805         public function getArticleID( $flags = 0 ) {
2806                 if ( $this->getNamespace() < 0 ) {
2807                         return $this->mArticleID = 0;
2808                 }
2809                 $linkCache = LinkCache::singleton();
2810                 if ( $flags & self::GAID_FOR_UPDATE ) {
2811                         $oldUpdate = $linkCache->forUpdate( true );
2812                         $linkCache->clearLink( $this );
2813                         $this->mArticleID = $linkCache->addLinkObj( $this );
2814                         $linkCache->forUpdate( $oldUpdate );
2815                 } else {
2816                         if ( -1 == $this->mArticleID ) {
2817                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2818                         }
2819                 }
2820                 return $this->mArticleID;
2821         }
2822
2823         /**
2824          * Is this an article that is a redirect page?
2825          * Uses link cache, adding it if necessary
2826          *
2827          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2828          * @return Bool
2829          */
2830         public function isRedirect( $flags = 0 ) {
2831                 if ( !is_null( $this->mRedirect ) ) {
2832                         return $this->mRedirect;
2833                 }
2834                 # Calling getArticleID() loads the field from cache as needed
2835                 if ( !$this->getArticleID( $flags ) ) {
2836                         return $this->mRedirect = false;
2837                 }
2838
2839                 $linkCache = LinkCache::singleton();
2840                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2841                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
2842                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2843                         #      as a stop gap, perhaps log this, but don't throw an exception?
2844                         throw new MWException( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2845                 }
2846
2847                 $this->mRedirect = (bool)$cached;
2848
2849                 return $this->mRedirect;
2850         }
2851
2852         /**
2853          * What is the length of this page?
2854          * Uses link cache, adding it if necessary
2855          *
2856          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2857          * @return Int
2858          */
2859         public function getLength( $flags = 0 ) {
2860                 if ( $this->mLength != -1 ) {
2861                         return $this->mLength;
2862                 }
2863                 # Calling getArticleID() loads the field from cache as needed
2864                 if ( !$this->getArticleID( $flags ) ) {
2865                         return $this->mLength = 0;
2866                 }
2867                 $linkCache = LinkCache::singleton();
2868                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
2869                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
2870                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2871                         #      as a stop gap, perhaps log this, but don't throw an exception?
2872                         throw new MWException( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2873                 }
2874
2875                 $this->mLength = intval( $cached );
2876
2877                 return $this->mLength;
2878         }
2879
2880         /**
2881          * What is the page_latest field for this page?
2882          *
2883          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2884          * @return Int or 0 if the page doesn't exist
2885          */
2886         public function getLatestRevID( $flags = 0 ) {
2887                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
2888                         return intval( $this->mLatestID );
2889                 }
2890                 # Calling getArticleID() loads the field from cache as needed
2891                 if ( !$this->getArticleID( $flags ) ) {
2892                         return $this->mLatestID = 0;
2893                 }
2894                 $linkCache = LinkCache::singleton();
2895                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
2896                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
2897                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2898                         #      as a stop gap, perhaps log this, but don't throw an exception?
2899                         throw new MWException( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2900                 }
2901
2902                 $this->mLatestID = intval( $cached );
2903
2904                 return $this->mLatestID;
2905         }
2906
2907         /**
2908          * This clears some fields in this object, and clears any associated
2909          * keys in the "bad links" section of the link cache.
2910          *
2911          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2912          * loading of the new page_id. It's also called from
2913          * WikiPage::doDeleteArticleReal()
2914          *
2915          * @param $newid Int the new Article ID
2916          */
2917         public function resetArticleID( $newid ) {
2918                 $linkCache = LinkCache::singleton();
2919                 $linkCache->clearLink( $this );
2920
2921                 if ( $newid === false ) {
2922                         $this->mArticleID = -1;
2923                 } else {
2924                         $this->mArticleID = intval( $newid );
2925                 }
2926                 $this->mRestrictionsLoaded = false;
2927                 $this->mRestrictions = array();
2928                 $this->mRedirect = null;
2929                 $this->mLength = -1;
2930                 $this->mLatestID = false;
2931                 $this->mContentModel = false;
2932                 $this->mEstimateRevisions = null;
2933         }
2934
2935         /**
2936          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2937          *
2938          * @param $text String containing title to capitalize
2939          * @param $ns int namespace index, defaults to NS_MAIN
2940          * @return String containing capitalized title
2941          */
2942         public static function capitalize( $text, $ns = NS_MAIN ) {
2943                 global $wgContLang;
2944
2945                 if ( MWNamespace::isCapitalized( $ns ) ) {
2946                         return $wgContLang->ucfirst( $text );
2947                 } else {
2948                         return $text;
2949                 }
2950         }
2951
2952         /**
2953          * Secure and split - main initialisation function for this object
2954          *
2955          * Assumes that mDbkeyform has been set, and is urldecoded
2956          * and uses underscores, but not otherwise munged.  This function
2957          * removes illegal characters, splits off the interwiki and
2958          * namespace prefixes, sets the other forms, and canonicalizes
2959          * everything.
2960          *
2961          * @return Bool true on success
2962          */
2963         private function secureAndSplit() {
2964                 global $wgContLang, $wgLocalInterwiki;
2965
2966                 # Initialisation
2967                 $this->mInterwiki = $this->mFragment = '';
2968                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2969
2970                 $dbkey = $this->mDbkeyform;
2971
2972                 # Strip Unicode bidi override characters.
2973                 # Sometimes they slip into cut-n-pasted page titles, where the
2974                 # override chars get included in list displays.
2975                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2976
2977                 # Clean up whitespace
2978                 # Note: use of the /u option on preg_replace here will cause
2979                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2980                 # conveniently disabling them.
2981                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2982                 $dbkey = trim( $dbkey, '_' );
2983
2984                 if ( $dbkey == '' ) {
2985                         return false;
2986                 }
2987
2988                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2989                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2990                         return false;
2991                 }
2992
2993                 $this->mDbkeyform = $dbkey;
2994
2995                 # Initial colon indicates main namespace rather than specified default
2996                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2997                 if ( ':' == $dbkey[0] ) {
2998                         $this->mNamespace = NS_MAIN;
2999                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
3000                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3001                 }
3002
3003                 # Namespace or interwiki prefix
3004                 $firstPass = true;
3005                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3006                 do {
3007                         $m = array();
3008                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3009                                 $p = $m[1];
3010                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3011                                         # Ordinary namespace
3012                                         $dbkey = $m[2];
3013                                         $this->mNamespace = $ns;
3014                                         # For Talk:X pages, check if X has a "namespace" prefix
3015                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3016                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3017                                                         # Disallow Talk:File:x type titles...
3018                                                         return false;
3019                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3020                                                         # Disallow Talk:Interwiki:x type titles...
3021                                                         return false;
3022                                                 }
3023                                         }
3024                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3025                                         if ( !$firstPass ) {
3026                                                 # Can't make a local interwiki link to an interwiki link.
3027                                                 # That's just crazy!
3028                                                 return false;
3029                                         }
3030
3031                                         # Interwiki link
3032                                         $dbkey = $m[2];
3033                                         $this->mInterwiki = $wgContLang->lc( $p );
3034
3035                                         # Redundant interwiki prefix to the local wiki
3036                                         if ( $wgLocalInterwiki !== false
3037                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3038                                         {
3039                                                 if ( $dbkey == '' ) {
3040                                                         # Can't have an empty self-link
3041                                                         return false;
3042                                                 }
3043                                                 $this->mInterwiki = '';
3044                                                 $firstPass = false;
3045                                                 # Do another namespace split...
3046                                                 continue;
3047                                         }
3048
3049                                         # If there's an initial colon after the interwiki, that also
3050                                         # resets the default namespace
3051                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3052                                                 $this->mNamespace = NS_MAIN;
3053                                                 $dbkey = substr( $dbkey, 1 );
3054                                         }
3055                                 }
3056                                 # If there's no recognized interwiki or namespace,
3057                                 # then let the colon expression be part of the title.
3058                         }
3059                         break;
3060                 } while ( true );
3061
3062                 # We already know that some pages won't be in the database!
3063                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3064                         $this->mArticleID = 0;
3065                 }
3066                 $fragment = strstr( $dbkey, '#' );
3067                 if ( false !== $fragment ) {
3068                         $this->setFragment( $fragment );
3069                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3070                         # remove whitespace again: prevents "Foo_bar_#"
3071                         # becoming "Foo_bar_"
3072                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3073                 }
3074
3075                 # Reject illegal characters.
3076                 $rxTc = self::getTitleInvalidRegex();
3077                 if ( preg_match( $rxTc, $dbkey ) ) {
3078                         return false;
3079                 }
3080
3081                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3082                 # reachable due to the way web browsers deal with 'relative' URLs.
3083                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3084                 if ( strpos( $dbkey, '.' ) !== false &&
3085                          ( $dbkey === '.' || $dbkey === '..' ||
3086                            strpos( $dbkey, './' ) === 0  ||
3087                            strpos( $dbkey, '../' ) === 0 ||
3088                            strpos( $dbkey, '/./' ) !== false ||
3089                            strpos( $dbkey, '/../' ) !== false  ||
3090                            substr( $dbkey, -2 ) == '/.' ||
3091                            substr( $dbkey, -3 ) == '/..' ) )
3092                 {
3093                         return false;
3094                 }
3095
3096                 # Magic tilde sequences? Nu-uh!
3097                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3098                         return false;
3099                 }
3100
3101                 # Limit the size of titles to 255 bytes. This is typically the size of the
3102                 # underlying database field. We make an exception for special pages, which
3103                 # don't need to be stored in the database, and may edge over 255 bytes due
3104                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3105                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3106                   strlen( $dbkey ) > 512 )
3107                 {
3108                         return false;
3109                 }
3110
3111                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3112                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3113                 # other site might be case-sensitive.
3114                 $this->mUserCaseDBKey = $dbkey;
3115                 if ( $this->mInterwiki == '' ) {
3116                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3117                 }
3118
3119                 # Can't make a link to a namespace alone... "empty" local links can only be
3120                 # self-links with a fragment identifier.
3121                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3122                         return false;
3123                 }
3124
3125                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3126                 // IP names are not allowed for accounts, and can only be referring to
3127                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3128                 // there are numerous ways to present the same IP. Having sp:contribs scan
3129                 // them all is silly and having some show the edits and others not is
3130                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3131                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3132                         ? IP::sanitizeIP( $dbkey )
3133                         : $dbkey;
3134
3135                 // Any remaining initial :s are illegal.
3136                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3137                         return false;
3138                 }
3139
3140                 # Fill fields
3141                 $this->mDbkeyform = $dbkey;
3142                 $this->mUrlform = wfUrlencode( $dbkey );
3143
3144                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3145
3146                 return true;
3147         }
3148
3149         /**
3150          * Get an array of Title objects linking to this Title
3151          * Also stores the IDs in the link cache.
3152          *
3153          * WARNING: do not use this function on arbitrary user-supplied titles!
3154          * On heavily-used templates it will max out the memory.
3155          *
3156          * @param $options Array: may be FOR UPDATE
3157          * @param $table String: table name
3158          * @param $prefix String: fields prefix
3159          * @return Array of Title objects linking here
3160          */
3161         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3162                 if ( count( $options ) > 0 ) {
3163                         $db = wfGetDB( DB_MASTER );
3164                 } else {
3165                         $db = wfGetDB( DB_SLAVE );
3166                 }
3167
3168                 $res = $db->select(
3169                         array( 'page', $table ),
3170                         self::getSelectFields(),
3171                         array(
3172                                 "{$prefix}_from=page_id",
3173                                 "{$prefix}_namespace" => $this->getNamespace(),
3174                                 "{$prefix}_title"     => $this->getDBkey() ),
3175                         __METHOD__,
3176                         $options
3177                 );
3178
3179                 $retVal = array();
3180                 if ( $res->numRows() ) {
3181                         $linkCache = LinkCache::singleton();
3182                         foreach ( $res as $row ) {
3183                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3184                                 if ( $titleObj ) {
3185                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3186                                         $retVal[] = $titleObj;
3187                                 }
3188                         }
3189                 }
3190                 return $retVal;
3191         }
3192
3193         /**
3194          * Get an array of Title objects using this Title as a template
3195          * Also stores the IDs in the link cache.
3196          *
3197          * WARNING: do not use this function on arbitrary user-supplied titles!
3198          * On heavily-used templates it will max out the memory.
3199          *
3200          * @param $options Array: may be FOR UPDATE
3201          * @return Array of Title the Title objects linking here
3202          */
3203         public function getTemplateLinksTo( $options = array() ) {
3204                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3205         }
3206
3207         /**
3208          * Get an array of Title objects linked from this Title
3209          * Also stores the IDs in the link cache.
3210          *
3211          * WARNING: do not use this function on arbitrary user-supplied titles!
3212          * On heavily-used templates it will max out the memory.
3213          *
3214          * @param $options Array: may be FOR UPDATE
3215          * @param $table String: table name
3216          * @param $prefix String: fields prefix
3217          * @return Array of Title objects linking here
3218          */
3219         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3220                 global $wgContentHandlerUseDB;
3221
3222                 $id = $this->getArticleID();
3223
3224                 # If the page doesn't exist; there can't be any link from this page
3225                 if ( !$id ) {
3226                         return array();
3227                 }
3228
3229                 if ( count( $options ) > 0 ) {
3230                         $db = wfGetDB( DB_MASTER );
3231                 } else {
3232                         $db = wfGetDB( DB_SLAVE );
3233                 }
3234
3235                 $namespaceFiled = "{$prefix}_namespace";
3236                 $titleField = "{$prefix}_title";
3237
3238                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3239                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3240
3241                 $res = $db->select(
3242                         array( $table, 'page' ),
3243                         $fields,
3244                         array( "{$prefix}_from" => $id ),
3245                         __METHOD__,
3246                         $options,
3247                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3248                 );
3249
3250                 $retVal = array();
3251                 if ( $res->numRows() ) {
3252                         $linkCache = LinkCache::singleton();
3253                         foreach ( $res as $row ) {
3254                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3255                                 if ( $titleObj ) {
3256                                         if ( $row->page_id ) {
3257                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3258                                         } else {
3259                                                 $linkCache->addBadLinkObj( $titleObj );
3260                                         }
3261                                         $retVal[] = $titleObj;
3262                                 }
3263                         }
3264                 }
3265                 return $retVal;
3266         }
3267
3268         /**
3269          * Get an array of Title objects used on this Title as a template
3270          * Also stores the IDs in the link cache.
3271          *
3272          * WARNING: do not use this function on arbitrary user-supplied titles!
3273          * On heavily-used templates it will max out the memory.
3274          *
3275          * @param $options Array: may be FOR UPDATE
3276          * @return Array of Title the Title objects used here
3277          */
3278         public function getTemplateLinksFrom( $options = array() ) {
3279                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3280         }
3281
3282         /**
3283          * Get an array of Title objects referring to non-existent articles linked from this page
3284          *
3285          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3286          * @return Array of Title the Title objects
3287          */
3288         public function getBrokenLinksFrom() {
3289                 if ( $this->getArticleID() == 0 ) {
3290                         # All links from article ID 0 are false positives
3291                         return array();
3292                 }
3293
3294                 $dbr = wfGetDB( DB_SLAVE );
3295                 $res = $dbr->select(
3296                         array( 'page', 'pagelinks' ),
3297                         array( 'pl_namespace', 'pl_title' ),
3298                         array(
3299                                 'pl_from' => $this->getArticleID(),
3300                                 'page_namespace IS NULL'
3301                         ),
3302                         __METHOD__, array(),
3303                         array(
3304                                 'page' => array(
3305                                         'LEFT JOIN',
3306                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3307                                 )
3308                         )
3309                 );
3310
3311                 $retVal = array();
3312                 foreach ( $res as $row ) {
3313                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3314                 }
3315                 return $retVal;
3316         }
3317
3318
3319         /**
3320          * Get a list of URLs to purge from the Squid cache when this
3321          * page changes
3322          *
3323          * @return Array of String the URLs
3324          */
3325         public function getSquidURLs() {
3326                 $urls = array(
3327                         $this->getInternalURL(),
3328                         $this->getInternalURL( 'action=history' )
3329                 );
3330
3331                 $pageLang = $this->getPageLanguage();
3332                 if ( $pageLang->hasVariants() ) {
3333                         $variants = $pageLang->getVariants();
3334                         foreach ( $variants as $vCode ) {
3335                                 $urls[] = $this->getInternalURL( '', $vCode );
3336                         }
3337                 }
3338
3339                 return $urls;
3340         }
3341
3342         /**
3343          * Purge all applicable Squid URLs
3344          */
3345         public function purgeSquid() {
3346                 global $wgUseSquid;
3347                 if ( $wgUseSquid ) {
3348                         $urls = $this->getSquidURLs();
3349                         $u = new SquidUpdate( $urls );
3350                         $u->doUpdate();
3351                 }
3352         }
3353
3354         /**
3355          * Move this page without authentication
3356          *
3357          * @param $nt Title the new page Title
3358          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3359          */
3360         public function moveNoAuth( &$nt ) {
3361                 return $this->moveTo( $nt, false );
3362         }
3363
3364         /**
3365          * Check whether a given move operation would be valid.
3366          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3367          *
3368          * @param $nt Title the new title
3369          * @param $auth Bool indicates whether $wgUser's permissions
3370          *  should be checked
3371          * @param $reason String is the log summary of the move, used for spam checking
3372          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3373          */
3374         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3375                 global $wgUser;
3376
3377                 $errors = array();
3378                 if ( !$nt ) {
3379                         // Normally we'd add this to $errors, but we'll get
3380                         // lots of syntax errors if $nt is not an object
3381                         return array( array( 'badtitletext' ) );
3382                 }
3383                 if ( $this->equals( $nt ) ) {
3384                         $errors[] = array( 'selfmove' );
3385                 }
3386                 if ( !$this->isMovable() ) {
3387                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3388                 }
3389                 if ( $nt->getInterwiki() != '' ) {
3390                         $errors[] = array( 'immobile-target-namespace-iw' );
3391                 }
3392                 if ( !$nt->isMovable() ) {
3393                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3394                 }
3395
3396                 $oldid = $this->getArticleID();
3397                 $newid = $nt->getArticleID();
3398
3399                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3400                         $errors[] = array( 'articleexists' );
3401                 }
3402                 if ( ( $this->getDBkey() == '' ) ||
3403                          ( !$oldid ) ||
3404                          ( $nt->getDBkey() == '' ) ) {
3405                         $errors[] = array( 'badarticleerror' );
3406                 }
3407
3408                 // Image-specific checks
3409                 if ( $this->getNamespace() == NS_FILE ) {
3410                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3411                 }
3412
3413                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3414                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3415                 }
3416
3417                 if ( $auth ) {
3418                         $errors = wfMergeErrorArrays( $errors,
3419                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3420                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3421                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3422                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3423                 }
3424
3425                 $match = EditPage::matchSummarySpamRegex( $reason );
3426                 if ( $match !== false ) {
3427                         // This is kind of lame, won't display nice
3428                         $errors[] = array( 'spamprotectiontext' );
3429                 }
3430
3431                 $err = null;
3432                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3433                         $errors[] = array( 'hookaborted', $err );
3434                 }
3435
3436                 # The move is allowed only if (1) the target doesn't exist, or
3437                 # (2) the target is a redirect to the source, and has no history
3438                 # (so we can undo bad moves right after they're done).
3439
3440                 if ( 0 != $newid ) { # Target exists; check for validity
3441                         if ( !$this->isValidMoveTarget( $nt ) ) {
3442                                 $errors[] = array( 'articleexists' );
3443                         }
3444                 } else {
3445                         $tp = $nt->getTitleProtection();
3446                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3447                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3448                                 $errors[] = array( 'cantmove-titleprotected' );
3449                         }
3450                 }
3451                 if ( empty( $errors ) ) {
3452                         return true;
3453                 }
3454                 return $errors;
3455         }
3456
3457         /**
3458          * Check if the requested move target is a valid file move target
3459          * @param Title $nt Target title
3460          * @return array List of errors
3461          */
3462         protected function validateFileMoveOperation( $nt ) {
3463                 global $wgUser;
3464
3465                 $errors = array();
3466
3467                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3468
3469                 $file = wfLocalFile( $this );
3470                 if ( $file->exists() ) {
3471                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3472                                 $errors[] = array( 'imageinvalidfilename' );
3473                         }
3474                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3475                                 $errors[] = array( 'imagetypemismatch' );
3476                         }
3477                 }
3478
3479                 if ( $nt->getNamespace() != NS_FILE ) {
3480                         $errors[] = array( 'imagenocrossnamespace' );
3481                         // From here we want to do checks on a file object, so if we can't
3482                         // create one, we must return.
3483                         return $errors;
3484                 }
3485
3486                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3487
3488                 $destFile = wfLocalFile( $nt );
3489                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3490                         $errors[] = array( 'file-exists-sharedrepo' );
3491                 }
3492
3493                 return $errors;
3494         }
3495
3496         /**
3497          * Move a title to a new location
3498          *
3499          * @param $nt Title the new title
3500          * @param $auth Bool indicates whether $wgUser's permissions
3501          *  should be checked
3502          * @param $reason String the reason for the move
3503          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3504          *  Ignored if the user doesn't have the suppressredirect right.
3505          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3506          */
3507         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3508                 global $wgUser;
3509                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3510                 if ( is_array( $err ) ) {
3511                         // Auto-block user's IP if the account was "hard" blocked
3512                         $wgUser->spreadAnyEditBlock();
3513                         return $err;
3514                 }
3515                 // Check suppressredirect permission
3516                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3517                         $createRedirect = true;
3518                 }
3519
3520                 // If it is a file, move it first.
3521                 // It is done before all other moving stuff is done because it's hard to revert.
3522                 $dbw = wfGetDB( DB_MASTER );
3523                 if ( $this->getNamespace() == NS_FILE ) {
3524                         $file = wfLocalFile( $this );
3525                         if ( $file->exists() ) {
3526                                 $status = $file->move( $nt );
3527                                 if ( !$status->isOk() ) {
3528                                         return $status->getErrorsArray();
3529                                 }
3530                         }
3531                         // Clear RepoGroup process cache
3532                         RepoGroup::singleton()->clearCache( $this );
3533                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3534                 }
3535
3536                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3537                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3538                 $protected = $this->isProtected();
3539
3540                 // Do the actual move
3541                 $this->moveToInternal( $nt, $reason, $createRedirect );
3542
3543                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3544                 // cl_timestamp, which may disturb time-based lists on some sites.
3545                 $prefixes = $dbw->select(
3546                         'categorylinks',
3547                         array( 'cl_sortkey_prefix', 'cl_to' ),
3548                         array( 'cl_from' => $pageid ),
3549                         __METHOD__
3550                 );
3551                 foreach ( $prefixes as $prefixRow ) {
3552                         $prefix = $prefixRow->cl_sortkey_prefix;
3553                         $catTo = $prefixRow->cl_to;
3554                         $dbw->update( 'categorylinks',
3555                                 array(
3556                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3557                                                 $nt->getCategorySortkey( $prefix ) ),
3558                                         'cl_timestamp=cl_timestamp' ),
3559                                 array(
3560                                         'cl_from' => $pageid,
3561                                         'cl_to' => $catTo ),
3562                                 __METHOD__
3563                         );
3564                 }
3565
3566                 $redirid = $this->getArticleID();
3567
3568                 if ( $protected ) {
3569                         # Protect the redirect title as the title used to be...
3570                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3571                                 array(
3572                                         'pr_page'    => $redirid,
3573                                         'pr_type'    => 'pr_type',
3574                                         'pr_level'   => 'pr_level',
3575                                         'pr_cascade' => 'pr_cascade',
3576                                         'pr_user'    => 'pr_user',
3577                                         'pr_expiry'  => 'pr_expiry'
3578                                 ),
3579                                 array( 'pr_page' => $pageid ),
3580                                 __METHOD__,
3581                                 array( 'IGNORE' )
3582                         );
3583                         # Update the protection log
3584                         $log = new LogPage( 'protect' );
3585                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3586                         if ( $reason ) {
3587                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3588                         }
3589                         // @todo FIXME: $params?
3590                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3591                 }
3592
3593                 # Update watchlists
3594                 $oldnamespace = $this->getNamespace() & ~1;
3595                 $newnamespace = $nt->getNamespace() & ~1;
3596                 $oldtitle = $this->getDBkey();
3597                 $newtitle = $nt->getDBkey();
3598
3599                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3600                         WatchedItem::duplicateEntries( $this, $nt );
3601                 }
3602
3603                 $dbw->commit( __METHOD__ );
3604
3605                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3606                 return true;
3607         }
3608
3609         /**
3610          * Move page to a title which is either a redirect to the
3611          * source page or nonexistent
3612          *
3613          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3614          * @param $reason String The reason for the move
3615          * @param $createRedirect Bool Whether to leave a redirect at the old title. Does not check
3616          *   if the user has the suppressredirect right
3617          * @throws MWException
3618          */
3619         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3620                 global $wgUser, $wgContLang;
3621
3622                 if ( $nt->exists() ) {
3623                         $moveOverRedirect = true;
3624                         $logType = 'move_redir';
3625                 } else {
3626                         $moveOverRedirect = false;
3627                         $logType = 'move';
3628                 }
3629
3630                 $redirectSuppressed = !$createRedirect;
3631
3632                 $logEntry = new ManualLogEntry( 'move', $logType );
3633                 $logEntry->setPerformer( $wgUser );
3634                 $logEntry->setTarget( $this );
3635                 $logEntry->setComment( $reason );
3636                 $logEntry->setParameters( array(
3637                         '4::target' => $nt->getPrefixedText(),
3638                         '5::noredir' => $redirectSuppressed ? '1': '0',
3639                 ) );
3640
3641                 $formatter = LogFormatter::newFromEntry( $logEntry );
3642                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3643                 $comment = $formatter->getPlainActionText();
3644                 if ( $reason ) {
3645                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3646                 }
3647                 # Truncate for whole multibyte characters.
3648                 $comment = $wgContLang->truncate( $comment, 255 );
3649
3650                 $oldid = $this->getArticleID();
3651
3652                 $dbw = wfGetDB( DB_MASTER );
3653
3654                 $newpage = WikiPage::factory( $nt );
3655
3656                 if ( $moveOverRedirect ) {
3657                         $newid = $nt->getArticleID();
3658
3659                         # Delete the old redirect. We don't save it to history since
3660                         # by definition if we've got here it's rather uninteresting.
3661                         # We have to remove it so that the next step doesn't trigger
3662                         # a conflict on the unique namespace+title index...
3663                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3664
3665                         $newpage->doDeleteUpdates( $newid );
3666                 }
3667
3668                 # Save a null revision in the page's history notifying of the move
3669                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3670                 if ( !is_object( $nullRevision ) ) {
3671                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3672                 }
3673                 $nullRevId = $nullRevision->insertOn( $dbw );
3674
3675                 # Change the name of the target page:
3676                 $dbw->update( 'page',
3677                         /* SET */ array(
3678                                 'page_namespace' => $nt->getNamespace(),
3679                                 'page_title'     => $nt->getDBkey(),
3680                         ),
3681                         /* WHERE */ array( 'page_id' => $oldid ),
3682                         __METHOD__
3683                 );
3684
3685                 $this->resetArticleID( 0 );
3686                 $nt->resetArticleID( $oldid );
3687
3688                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3689
3690                 wfRunHooks( 'NewRevisionFromEditComplete',
3691                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3692
3693                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3694
3695                 if ( !$moveOverRedirect ) {
3696                         WikiPage::onArticleCreate( $nt );
3697                 }
3698
3699                 # Recreate the redirect, this time in the other direction.
3700                 if ( $redirectSuppressed ) {
3701                         WikiPage::onArticleDelete( $this );
3702                 } else {
3703                         $mwRedir = MagicWord::get( 'redirect' );
3704                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3705                         $redirectArticle = WikiPage::factory( $this );
3706                         $newid = $redirectArticle->insertOn( $dbw );
3707                         if ( $newid ) { // sanity
3708                                 $redirectRevision = new Revision( array(
3709                                         'page'    => $newid,
3710                                         'comment' => $comment,
3711                                         'text'    => $redirectText ) );
3712                                 $redirectRevision->insertOn( $dbw );
3713                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3714
3715                                 wfRunHooks( 'NewRevisionFromEditComplete',
3716                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3717
3718                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3719                         }
3720                 }
3721
3722                 # Log the move
3723                 $logid = $logEntry->insert();
3724                 $logEntry->publish( $logid );
3725         }
3726
3727         /**
3728          * Move this page's subpages to be subpages of $nt
3729          *
3730          * @param $nt Title Move target
3731          * @param $auth bool Whether $wgUser's permissions should be checked
3732          * @param $reason string The reason for the move
3733          * @param $createRedirect bool Whether to create redirects from the old subpages to
3734          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3735          * @return mixed array with old page titles as keys, and strings (new page titles) or
3736          *     arrays (errors) as values, or an error array with numeric indices if no pages
3737          *     were moved
3738          */
3739         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3740                 global $wgMaximumMovedPages;
3741                 // Check permissions
3742                 if ( !$this->userCan( 'move-subpages' ) ) {
3743                         return array( 'cant-move-subpages' );
3744                 }
3745                 // Do the source and target namespaces support subpages?
3746                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3747                         return array( 'namespace-nosubpages',
3748                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3749                 }
3750                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3751                         return array( 'namespace-nosubpages',
3752                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3753                 }
3754
3755                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3756                 $retval = array();
3757                 $count = 0;
3758                 foreach ( $subpages as $oldSubpage ) {
3759                         $count++;
3760                         if ( $count > $wgMaximumMovedPages ) {
3761                                 $retval[$oldSubpage->getPrefixedTitle()] =
3762                                                 array( 'movepage-max-pages',
3763                                                         $wgMaximumMovedPages );
3764                                 break;
3765                         }
3766
3767                         // We don't know whether this function was called before
3768                         // or after moving the root page, so check both
3769                         // $this and $nt
3770                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3771                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3772                         {
3773                                 // When moving a page to a subpage of itself,
3774                                 // don't move it twice
3775                                 continue;
3776                         }
3777                         $newPageName = preg_replace(
3778                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3779                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3780                                         $oldSubpage->getDBkey() );
3781                         if ( $oldSubpage->isTalkPage() ) {
3782                                 $newNs = $nt->getTalkPage()->getNamespace();
3783                         } else {
3784                                 $newNs = $nt->getSubjectPage()->getNamespace();
3785                         }
3786                         # Bug 14385: we need makeTitleSafe because the new page names may
3787                         # be longer than 255 characters.
3788                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3789
3790                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3791                         if ( $success === true ) {
3792                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3793                         } else {
3794                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3795                         }
3796                 }
3797                 return $retval;
3798         }
3799
3800         /**
3801          * Checks if this page is just a one-rev redirect.
3802          * Adds lock, so don't use just for light purposes.
3803          *
3804          * @return Bool
3805          */
3806         public function isSingleRevRedirect() {
3807                 global $wgContentHandlerUseDB;
3808
3809                 $dbw = wfGetDB( DB_MASTER );
3810
3811                 # Is it a redirect?
3812                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3813                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3814
3815                 $row = $dbw->selectRow( 'page',
3816                         $fields,
3817                         $this->pageCond(),
3818                         __METHOD__,
3819                         array( 'FOR UPDATE' )
3820                 );
3821                 # Cache some fields we may want
3822                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3823                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3824                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3825                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
3826                 if ( !$this->mRedirect ) {
3827                         return false;
3828                 }
3829                 # Does the article have a history?
3830                 $row = $dbw->selectField( array( 'page', 'revision' ),
3831                         'rev_id',
3832                         array( 'page_namespace' => $this->getNamespace(),
3833                                 'page_title' => $this->getDBkey(),
3834                                 'page_id=rev_page',
3835                                 'page_latest != rev_id'
3836                         ),
3837                         __METHOD__,
3838                         array( 'FOR UPDATE' )
3839                 );
3840                 # Return true if there was no history
3841                 return ( $row === false );
3842         }
3843
3844         /**
3845          * Checks if $this can be moved to a given Title
3846          * - Selects for update, so don't call it unless you mean business
3847          *
3848          * @param $nt Title the new title to check
3849          * @return Bool
3850          */
3851         public function isValidMoveTarget( $nt ) {
3852                 # Is it an existing file?
3853                 if ( $nt->getNamespace() == NS_FILE ) {
3854                         $file = wfLocalFile( $nt );
3855                         if ( $file->exists() ) {
3856                                 wfDebug( __METHOD__ . ": file exists\n" );
3857                                 return false;
3858                         }
3859                 }
3860                 # Is it a redirect with no history?
3861                 if ( !$nt->isSingleRevRedirect() ) {
3862                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3863                         return false;
3864                 }
3865                 # Get the article text
3866                 $rev = Revision::newFromTitle( $nt );
3867                 if( !is_object( $rev ) ){
3868                         return false;
3869                 }
3870                 $content = $rev->getContent();
3871                 # Does the redirect point to the source?
3872                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3873                 $redirTitle = $content->getRedirectTarget();
3874
3875                 if ( $redirTitle ) {
3876                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3877                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3878                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3879                                 return false;
3880                         } else {
3881                                 return true;
3882                         }
3883                 } else {
3884                         # Fail safe (not a redirect after all. strange.)
3885                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() . " is a redirect, but it doesn't contain a valid redirect.\n" );
3886                         return false;
3887                 }
3888         }
3889
3890         /**
3891          * Get categories to which this Title belongs and return an array of
3892          * categories' names.
3893          *
3894          * @return Array of parents in the form:
3895          *        $parent => $currentarticle
3896          */
3897         public function getParentCategories() {
3898                 global $wgContLang;
3899
3900                 $data = array();
3901
3902                 $titleKey = $this->getArticleID();
3903
3904                 if ( $titleKey === 0 ) {
3905                         return $data;
3906                 }
3907
3908                 $dbr = wfGetDB( DB_SLAVE );
3909
3910                 $res = $dbr->select( 'categorylinks', '*',
3911                         array(
3912                                 'cl_from' => $titleKey,
3913                         ),
3914                         __METHOD__,
3915                         array()
3916                 );
3917
3918                 if ( $dbr->numRows( $res ) > 0 ) {
3919                         foreach ( $res as $row ) {
3920                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3921                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3922                         }
3923                 }
3924                 return $data;
3925         }
3926
3927         /**
3928          * Get a tree of parent categories
3929          *
3930          * @param $children Array with the children in the keys, to check for circular refs
3931          * @return Array Tree of parent categories
3932          */
3933         public function getParentCategoryTree( $children = array() ) {
3934                 $stack = array();
3935                 $parents = $this->getParentCategories();
3936
3937                 if ( $parents ) {
3938                         foreach ( $parents as $parent => $current ) {
3939                                 if ( array_key_exists( $parent, $children ) ) {
3940                                         # Circular reference
3941                                         $stack[$parent] = array();
3942                                 } else {
3943                                         $nt = Title::newFromText( $parent );
3944                                         if ( $nt ) {
3945                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3946                                         }
3947                                 }
3948                         }
3949                 }
3950
3951                 return $stack;
3952         }
3953
3954         /**
3955          * Get an associative array for selecting this title from
3956          * the "page" table
3957          *
3958          * @return Array suitable for the $where parameter of DB::select()
3959          */
3960         public function pageCond() {
3961                 if ( $this->mArticleID > 0 ) {
3962                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3963                         return array( 'page_id' => $this->mArticleID );
3964                 } else {
3965                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3966                 }
3967         }
3968
3969         /**
3970          * Get the revision ID of the previous revision
3971          *
3972          * @param $revId Int Revision ID. Get the revision that was before this one.
3973          * @param $flags Int Title::GAID_FOR_UPDATE
3974          * @return Int|Bool Old revision ID, or FALSE if none exists
3975          */
3976         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3977                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3978                 $revId = $db->selectField( 'revision', 'rev_id',
3979                         array(
3980                                 'rev_page' => $this->getArticleID( $flags ),
3981                                 'rev_id < ' . intval( $revId )
3982                         ),
3983                         __METHOD__,
3984                         array( 'ORDER BY' => 'rev_id DESC' )
3985                 );
3986
3987                 if ( $revId === false ) {
3988                         return false;
3989                 } else {
3990                         return intval( $revId );
3991                 }
3992         }
3993
3994         /**
3995          * Get the revision ID of the next revision
3996          *
3997          * @param $revId Int Revision ID. Get the revision that was after this one.
3998          * @param $flags Int Title::GAID_FOR_UPDATE
3999          * @return Int|Bool Next revision ID, or FALSE if none exists
4000          */
4001         public function getNextRevisionID( $revId, $flags = 0 ) {
4002                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4003                 $revId = $db->selectField( 'revision', 'rev_id',
4004                         array(
4005                                 'rev_page' => $this->getArticleID( $flags ),
4006                                 'rev_id > ' . intval( $revId )
4007                         ),
4008                         __METHOD__,
4009                         array( 'ORDER BY' => 'rev_id' )
4010                 );
4011
4012                 if ( $revId === false ) {
4013                         return false;
4014                 } else {
4015                         return intval( $revId );
4016                 }
4017         }
4018
4019         /**
4020          * Get the first revision of the page
4021          *
4022          * @param $flags Int Title::GAID_FOR_UPDATE
4023          * @return Revision|Null if page doesn't exist
4024          */
4025         public function getFirstRevision( $flags = 0 ) {
4026                 $pageId = $this->getArticleID( $flags );
4027                 if ( $pageId ) {
4028                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4029                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4030                                 array( 'rev_page' => $pageId ),
4031                                 __METHOD__,
4032                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4033                         );
4034                         if ( $row ) {
4035                                 return new Revision( $row );
4036                         }
4037                 }
4038                 return null;
4039         }
4040
4041         /**
4042          * Get the oldest revision timestamp of this page
4043          *
4044          * @param $flags Int Title::GAID_FOR_UPDATE
4045          * @return String: MW timestamp
4046          */
4047         public function getEarliestRevTime( $flags = 0 ) {
4048                 $rev = $this->getFirstRevision( $flags );
4049                 return $rev ? $rev->getTimestamp() : null;
4050         }
4051
4052         /**
4053          * Check if this is a new page
4054          *
4055          * @return bool
4056          */
4057         public function isNewPage() {
4058                 $dbr = wfGetDB( DB_SLAVE );
4059                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4060         }
4061
4062         /**
4063          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4064          *
4065          * @return bool
4066          */
4067         public function isBigDeletion() {
4068                 global $wgDeleteRevisionsLimit;
4069
4070                 if ( !$wgDeleteRevisionsLimit ) {
4071                         return false;
4072                 }
4073
4074                 $revCount = $this->estimateRevisionCount();
4075                 return $revCount > $wgDeleteRevisionsLimit;
4076         }
4077
4078         /**
4079          * Get the  approximate revision count of this page.
4080          *
4081          * @return int
4082          */
4083         public function estimateRevisionCount() {
4084                 if ( !$this->exists() ) {
4085                         return 0;
4086                 }
4087
4088                 if ( $this->mEstimateRevisions === null ) {
4089                         $dbr = wfGetDB( DB_SLAVE );
4090                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4091                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4092                 }
4093
4094                 return $this->mEstimateRevisions;
4095         }
4096
4097         /**
4098          * Get the number of revisions between the given revision.
4099          * Used for diffs and other things that really need it.
4100          *
4101          * @param $old int|Revision Old revision or rev ID (first before range)
4102          * @param $new int|Revision New revision or rev ID (first after range)
4103          * @return Int Number of revisions between these revisions.
4104          */
4105         public function countRevisionsBetween( $old, $new ) {
4106                 if ( !( $old instanceof Revision ) ) {
4107                         $old = Revision::newFromTitle( $this, (int)$old );
4108                 }
4109                 if ( !( $new instanceof Revision ) ) {
4110                         $new = Revision::newFromTitle( $this, (int)$new );
4111                 }
4112                 if ( !$old || !$new ) {
4113                         return 0; // nothing to compare
4114                 }
4115                 $dbr = wfGetDB( DB_SLAVE );
4116                 return (int)$dbr->selectField( 'revision', 'count(*)',
4117                         array(
4118                                 'rev_page' => $this->getArticleID(),
4119                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4120                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4121                         ),
4122                         __METHOD__
4123                 );
4124         }
4125
4126         /**
4127          * Get the number of authors between the given revision IDs.
4128          * Used for diffs and other things that really need it.
4129          *
4130          * @param $old int|Revision Old revision or rev ID (first before range)
4131          * @param $new int|Revision New revision or rev ID (first after range)
4132          * @param $limit Int Maximum number of authors
4133          * @return Int Number of revision authors between these revisions.
4134          */
4135         public function countAuthorsBetween( $old, $new, $limit ) {
4136                 if ( !( $old instanceof Revision ) ) {
4137                         $old = Revision::newFromTitle( $this, (int)$old );
4138                 }
4139                 if ( !( $new instanceof Revision ) ) {
4140                         $new = Revision::newFromTitle( $this, (int)$new );
4141                 }
4142                 if ( !$old || !$new ) {
4143                         return 0; // nothing to compare
4144                 }
4145                 $dbr = wfGetDB( DB_SLAVE );
4146                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4147                         array(
4148                                 'rev_page' => $this->getArticleID(),
4149                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4150                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4151                         ), __METHOD__,
4152                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4153                 );
4154                 return (int)$dbr->numRows( $res );
4155         }
4156
4157         /**
4158          * Compare with another title.
4159          *
4160          * @param $title Title
4161          * @return Bool
4162          */
4163         public function equals( Title $title ) {
4164                 // Note: === is necessary for proper matching of number-like titles.
4165                 return $this->getInterwiki() === $title->getInterwiki()
4166                         && $this->getNamespace() == $title->getNamespace()
4167                         && $this->getDBkey() === $title->getDBkey();
4168         }
4169
4170         /**
4171          * Check if this title is a subpage of another title
4172          *
4173          * @param $title Title
4174          * @return Bool
4175          */
4176         public function isSubpageOf( Title $title ) {
4177                 return $this->getInterwiki() === $title->getInterwiki()
4178                         && $this->getNamespace() == $title->getNamespace()
4179                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4180         }
4181
4182         /**
4183          * Check if page exists.  For historical reasons, this function simply
4184          * checks for the existence of the title in the page table, and will
4185          * thus return false for interwiki links, special pages and the like.
4186          * If you want to know if a title can be meaningfully viewed, you should
4187          * probably call the isKnown() method instead.
4188          *
4189          * @return Bool
4190          */
4191         public function exists() {
4192                 return $this->getArticleID() != 0;
4193         }
4194
4195         /**
4196          * Should links to this title be shown as potentially viewable (i.e. as
4197          * "bluelinks"), even if there's no record by this title in the page
4198          * table?
4199          *
4200          * This function is semi-deprecated for public use, as well as somewhat
4201          * misleadingly named.  You probably just want to call isKnown(), which
4202          * calls this function internally.
4203          *
4204          * (ISSUE: Most of these checks are cheap, but the file existence check
4205          * can potentially be quite expensive.  Including it here fixes a lot of
4206          * existing code, but we might want to add an optional parameter to skip
4207          * it and any other expensive checks.)
4208          *
4209          * @return Bool
4210          */
4211         public function isAlwaysKnown() {
4212                 $isKnown = null;
4213
4214                 /**
4215                  * Allows overriding default behaviour for determining if a page exists.
4216                  * If $isKnown is kept as null, regular checks happen. If it's
4217                  * a boolean, this value is returned by the isKnown method.
4218                  *
4219                  * @since 1.20
4220                  *
4221                  * @param Title $title
4222                  * @param boolean|null $isKnown
4223                  */
4224                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4225
4226                 if ( !is_null( $isKnown ) ) {
4227                         return $isKnown;
4228                 }
4229
4230                 if ( $this->mInterwiki != '' ) {
4231                         return true;  // any interwiki link might be viewable, for all we know
4232                 }
4233
4234                 switch( $this->mNamespace ) {
4235                         case NS_MEDIA:
4236                         case NS_FILE:
4237                                 // file exists, possibly in a foreign repo
4238                                 return (bool)wfFindFile( $this );
4239                         case NS_SPECIAL:
4240                                 // valid special page
4241                                 return SpecialPageFactory::exists( $this->getDBkey() );
4242                         case NS_MAIN:
4243                                 // selflink, possibly with fragment
4244                                 return $this->mDbkeyform == '';
4245                         case NS_MEDIAWIKI:
4246                                 // known system message
4247                                 return $this->hasSourceText() !== false;
4248                         default:
4249                                 return false;
4250                 }
4251         }
4252
4253         /**
4254          * Does this title refer to a page that can (or might) be meaningfully
4255          * viewed?  In particular, this function may be used to determine if
4256          * links to the title should be rendered as "bluelinks" (as opposed to
4257          * "redlinks" to non-existent pages).
4258          * Adding something else to this function will cause inconsistency
4259          * since LinkHolderArray calls isAlwaysKnown() and does its own
4260          * page existence check.
4261          *
4262          * @return Bool
4263          */
4264         public function isKnown() {
4265                 return $this->isAlwaysKnown() || $this->exists();
4266         }
4267
4268         /**
4269          * Does this page have source text?
4270          *
4271          * @return Boolean
4272          */
4273         public function hasSourceText() {
4274                 if ( $this->exists() ) {
4275                         return true;
4276                 }
4277
4278                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4279                         // If the page doesn't exist but is a known system message, default
4280                         // message content will be displayed, same for language subpages-
4281                         // Use always content language to avoid loading hundreds of languages
4282                         // to get the link color.
4283                         global $wgContLang;
4284                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4285                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4286                         return $message->exists();
4287                 }
4288
4289                 return false;
4290         }
4291
4292         /**
4293          * Get the default message text or false if the message doesn't exist
4294          *
4295          * @return String or false
4296          */
4297         public function getDefaultMessageText() {
4298                 global $wgContLang;
4299
4300                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4301                         return false;
4302                 }
4303
4304                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4305                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4306
4307                 if ( $message->exists() ) {
4308                         return $message->plain();
4309                 } else {
4310                         return false;
4311                 }
4312         }
4313
4314         /**
4315          * Updates page_touched for this page; called from LinksUpdate.php
4316          *
4317          * @return Bool true if the update succeded
4318          */
4319         public function invalidateCache() {
4320                 if ( wfReadOnly() ) {
4321                         return false;
4322                 }
4323                 $dbw = wfGetDB( DB_MASTER );
4324                 $success = $dbw->update(
4325                         'page',
4326                         array( 'page_touched' => $dbw->timestamp() ),
4327                         $this->pageCond(),
4328                         __METHOD__
4329                 );
4330                 HTMLFileCache::clearFileCache( $this );
4331                 return $success;
4332         }
4333
4334         /**
4335          * Update page_touched timestamps and send squid purge messages for
4336          * pages linking to this title. May be sent to the job queue depending
4337          * on the number of links. Typically called on create and delete.
4338          */
4339         public function touchLinks() {
4340                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4341                 $u->doUpdate();
4342
4343                 if ( $this->getNamespace() == NS_CATEGORY ) {
4344                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4345                         $u->doUpdate();
4346                 }
4347         }
4348
4349         /**
4350          * Get the last touched timestamp
4351          *
4352          * @param $db DatabaseBase: optional db
4353          * @return String last-touched timestamp
4354          */
4355         public function getTouched( $db = null ) {
4356                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4357                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4358                 return $touched;
4359         }
4360
4361         /**
4362          * Get the timestamp when this page was updated since the user last saw it.
4363          *
4364          * @param $user User
4365          * @return String|Null
4366          */
4367         public function getNotificationTimestamp( $user = null ) {
4368                 global $wgUser, $wgShowUpdatedMarker;
4369                 // Assume current user if none given
4370                 if ( !$user ) {
4371                         $user = $wgUser;
4372                 }
4373                 // Check cache first
4374                 $uid = $user->getId();
4375                 // avoid isset here, as it'll return false for null entries
4376                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4377                         return $this->mNotificationTimestamp[$uid];
4378                 }
4379                 if ( !$uid || !$wgShowUpdatedMarker ) {
4380                         return $this->mNotificationTimestamp[$uid] = false;
4381                 }
4382                 // Don't cache too much!
4383                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4384                         $this->mNotificationTimestamp = array();
4385                 }
4386                 $dbr = wfGetDB( DB_SLAVE );
4387                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4388                         'wl_notificationtimestamp',
4389                         array(
4390                                 'wl_user' => $user->getId(),
4391                                 'wl_namespace' => $this->getNamespace(),
4392                                 'wl_title' => $this->getDBkey(),
4393                         ),
4394                         __METHOD__
4395                 );
4396                 return $this->mNotificationTimestamp[$uid];
4397         }
4398
4399         /**
4400          * Generate strings used for xml 'id' names in monobook tabs
4401          *
4402          * @param $prepend string defaults to 'nstab-'
4403          * @return String XML 'id' name
4404          */
4405         public function getNamespaceKey( $prepend = 'nstab-' ) {
4406                 global $wgContLang;
4407                 // Gets the subject namespace if this title
4408                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4409                 // Checks if cononical namespace name exists for namespace
4410                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4411                         // Uses canonical namespace name
4412                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4413                 } else {
4414                         // Uses text of namespace
4415                         $namespaceKey = $this->getSubjectNsText();
4416                 }
4417                 // Makes namespace key lowercase
4418                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4419                 // Uses main
4420                 if ( $namespaceKey == '' ) {
4421                         $namespaceKey = 'main';
4422                 }
4423                 // Changes file to image for backwards compatibility
4424                 if ( $namespaceKey == 'file' ) {
4425                         $namespaceKey = 'image';
4426                 }
4427                 return $prepend . $namespaceKey;
4428         }
4429
4430         /**
4431          * Get all extant redirects to this Title
4432          *
4433          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4434          * @return Array of Title redirects to this title
4435          */
4436         public function getRedirectsHere( $ns = null ) {
4437                 $redirs = array();
4438
4439                 $dbr = wfGetDB( DB_SLAVE );
4440                 $where = array(
4441                         'rd_namespace' => $this->getNamespace(),
4442                         'rd_title' => $this->getDBkey(),
4443                         'rd_from = page_id'
4444                 );
4445                 if ( !is_null( $ns ) ) {
4446                         $where['page_namespace'] = $ns;
4447                 }
4448
4449                 $res = $dbr->select(
4450                         array( 'redirect', 'page' ),
4451                         array( 'page_namespace', 'page_title' ),
4452                         $where,
4453                         __METHOD__
4454                 );
4455
4456                 foreach ( $res as $row ) {
4457                         $redirs[] = self::newFromRow( $row );
4458                 }
4459                 return $redirs;
4460         }
4461
4462         /**
4463          * Check if this Title is a valid redirect target
4464          *
4465          * @return Bool
4466          */
4467         public function isValidRedirectTarget() {
4468                 global $wgInvalidRedirectTargets;
4469
4470                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4471                 if ( $this->isSpecial( 'Userlogout' ) ) {
4472                         return false;
4473                 }
4474
4475                 foreach ( $wgInvalidRedirectTargets as $target ) {
4476                         if ( $this->isSpecial( $target ) ) {
4477                                 return false;
4478                         }
4479                 }
4480
4481                 return true;
4482         }
4483
4484         /**
4485          * Get a backlink cache object
4486          *
4487          * @return BacklinkCache
4488          */
4489         function getBacklinkCache() {
4490                 if ( is_null( $this->mBacklinkCache ) ) {
4491                         $this->mBacklinkCache = new BacklinkCache( $this );
4492                 }
4493                 return $this->mBacklinkCache;
4494         }
4495
4496         /**
4497          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4498          *
4499          * @return Boolean
4500          */
4501         public function canUseNoindex() {
4502                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4503
4504                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4505                         ? $wgContentNamespaces
4506                         : $wgExemptFromUserRobotsControl;
4507
4508                 return !in_array( $this->mNamespace, $bannedNamespaces );
4509
4510         }
4511
4512         /**
4513          * Returns the raw sort key to be used for categories, with the specified
4514          * prefix.  This will be fed to Collation::getSortKey() to get a
4515          * binary sortkey that can be used for actual sorting.
4516          *
4517          * @param $prefix string The prefix to be used, specified using
4518          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4519          *   prefix.
4520          * @return string
4521          */
4522         public function getCategorySortkey( $prefix = '' ) {
4523                 $unprefixed = $this->getText();
4524
4525                 // Anything that uses this hook should only depend
4526                 // on the Title object passed in, and should probably
4527                 // tell the users to run updateCollations.php --force
4528                 // in order to re-sort existing category relations.
4529                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4530                 if ( $prefix !== '' ) {
4531                         # Separate with a line feed, so the unprefixed part is only used as
4532                         # a tiebreaker when two pages have the exact same prefix.
4533                         # In UCA, tab is the only character that can sort above LF
4534                         # so we strip both of them from the original prefix.
4535                         $prefix = strtr( $prefix, "\n\t", '  ' );
4536                         return "$prefix\n$unprefixed";
4537                 }
4538                 return $unprefixed;
4539         }
4540
4541         /**
4542          * Get the language in which the content of this page is written.
4543          * Defaults to $wgContLang, but in certain cases it can be e.g.
4544          * $wgLang (such as special pages, which are in the user language).
4545          *
4546          * @since 1.18
4547          * @return Language
4548          */
4549         public function getPageLanguage() {
4550                 global $wgLang;
4551                 if ( $this->isSpecialPage() ) {
4552                         // special pages are in the user language
4553                         return $wgLang;
4554                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4555                         // Parse mediawiki messages with correct target language
4556                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4557                         return wfGetLangObj( $lang );
4558                 }
4559
4560                 //TODO: use the LinkCache to cache this!
4561                 //NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4562                 $contentHandler = ContentHandler::getForTitle( $this );
4563                 $pageLang = $contentHandler->getPageLanguage( $this );
4564
4565                 // Hook at the end because we don't want to override the above stuff
4566                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4567                 return wfGetLangObj( $pageLang );
4568         }
4569 }