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          * Create a new Title from an article ID
 206          *
 207          * @param $id Int the page_id corresponding to the Title to create
 208          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 209          * @return Title the new object, or NULL on an error
 210          */
 211         public static function newFromID( $id, $flags = 0 ) {
 212                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 213                 $row = $db->selectRow(
 214                         'page',
 215                         array(
 216                                 'page_namespace', 'page_title', 'page_id',
 217                                 'page_len', 'page_is_redirect', 'page_latest',
 218                         ),
 219                         array( 'page_id' => $id ),
 220                         __METHOD__
 221                 );
 222                 if ( $row !== false ) {
 223                         $title = Title::newFromRow( $row );
 224                 } else {
 225                         $title = null;
 226                 }
 227                 return $title;
 228         }
 229
 230         /**
 231          * Make an array of titles from an array of IDs
 232          *
 233          * @param $ids Array of Int Array of IDs
 234          * @return Array of Titles
 235          */
 236         public static function newFromIDs( $ids ) {
 237                 if ( !count( $ids ) ) {
 238                         return array();
 239                 }
 240                 $dbr = wfGetDB( DB_SLAVE );
 241
 242                 $res = $dbr->select(
 243                         'page',
 244                         array(
 245                                 'page_namespace', 'page_title', 'page_id',
 246                                 'page_len', 'page_is_redirect', 'page_latest',
 247                         ),
 248                         array( 'page_id' => $ids ),
 249                         __METHOD__
 250                 );
 251
 252                 $titles = array();
 253                 foreach ( $res as $row ) {
 254                         $titles[] = Title::newFromRow( $row );
 255                 }
 256                 return $titles;
 257         }
 258
 259         /**
 260          * Make a Title object from a DB row
 261          *
 262          * @param $row Object database row (needs at least page_title,page_namespace)
 263          * @return Title corresponding Title
 264          */
 265         public static function newFromRow( $row ) {
 266                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 267                 $t->loadFromRow( $row );
 268                 return $t;
 269         }
 270
 271         /**
 272          * Load Title object fields from a DB row.
 273          * If false is given, the title will be treated as non-existing.
 274          *
 275          * @param $row Object|bool database row
 276          */
 277         public function loadFromRow( $row ) {
 278                 if ( $row ) { // page found
 279                         if ( isset( $row->page_id ) )
 280                                 $this->mArticleID = (int)$row->page_id;
 281                         if ( isset( $row->page_len ) )
 282                                 $this->mLength = (int)$row->page_len;
 283                         if ( isset( $row->page_is_redirect ) )
 284                                 $this->mRedirect = (bool)$row->page_is_redirect;
 285                         if ( isset( $row->page_latest ) )
 286                                 $this->mLatestID = (int)$row->page_latest; # FIXME: whene3ver page_latest is updated, also update page_content_model
 287                         if ( isset( $row->page_content_model ) )
 288                                 $this->mContentModel = intval( $row->page_content_model );
 289                         else
 290                                 $this->mContentModel = null; # initialized lazily in getContentModel()
 291                 } else { // page not found
 292                         $this->mArticleID = 0;
 293                         $this->mLength = 0;
 294                         $this->mRedirect = false;
 295                         $this->mLatestID = 0;
 296                         $this->mContentModel = null; # initialized lazily in getContentModel()
 297                 }
 298         }
 299
 300         /**
 301          * Create a new Title from a namespace index and a DB key.
 302          * It's assumed that $ns and $title are *valid*, for instance when
 303          * they came directly from the database or a special page name.
 304          * For convenience, spaces are converted to underscores so that
 305          * eg user_text fields can be used directly.
 306          *
 307          * @param $ns Int the namespace of the article
 308          * @param $title String the unprefixed database key form
 309          * @param $fragment String the link fragment (after the "#")
 310          * @param $interwiki String the interwiki prefix
 311          * @return Title the new object
 312          */
 313         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 314                 $t = new Title();
 315                 $t->mInterwiki = $interwiki;
 316                 $t->mFragment = $fragment;
 317                 $t->mNamespace = $ns = intval( $ns );
 318                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 319                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 320                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 321                 $t->mTextform = str_replace( '_', ' ', $title );
 322                 $t->mContentModel = null; # initialized lazily in getContentModel()
 323                 return $t;
 324         }
 325
 326         /**
 327          * Create a new Title from a namespace index and a DB key.
 328          * The parameters will be checked for validity, which is a bit slower
 329          * than makeTitle() but safer for user-provided data.
 330          *
 331          * @param $ns Int the namespace of the article
 332          * @param $title String database key form
 333          * @param $fragment String the link fragment (after the "#")
 334          * @param $interwiki String interwiki prefix
 335          * @return Title the new object, or NULL on an error
 336          */
 337         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 338                 if ( !MWNamespace::exists( $ns ) ) {
 339                         return null;
 340                 }
 341
 342                 $t = new Title();
 343                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 344                 if ( $t->secureAndSplit() ) {
 345                         return $t;
 346                 } else {
 347                         return null;
 348                 }
 349         }
 350
 351         /**
 352          * Create a new Title for the Main Page
 353          *
 354          * @return Title the new object
 355          */
 356         public static function newMainPage() {
 357                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 358                 // Don't give fatal errors if the message is broken
 359                 if ( !$title ) {
 360                         $title = Title::newFromText( 'Main Page' );
 361                 }
 362                 return $title;
 363         }
 364
 365         /**
 366          * Extract a redirect destination from a string and return the
 367          * Title, or null if the text doesn't contain a valid redirect
 368          * This will only return the very next target, useful for
 369          * the redirect table and other checks that don't need full recursion
 370          *
 371          * @param $text String: Text with possible redirect
 372          * @return Title: The corresponding Title
 373          */
 374         public static function newFromRedirect( $text ) { #TODO: move to Content class, deprecate here.
 375                 return self::newFromRedirectInternal( $text );
 376         }
 377
 378         /**
 379          * Extract a redirect destination from a string and return the
 380          * Title, or null if the text doesn't contain a valid redirect
 381          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 382          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 383          *
 384          * @param $text String Text with possible redirect
 385          * @return Title
 386          */
 387         public static function newFromRedirectRecurse( $text ) {
 388                 $titles = self::newFromRedirectArray( $text );
 389                 return $titles ? array_pop( $titles ) : null;
 390         }
 391
 392         /**
 393          * Extract a redirect destination from a string and return an
 394          * array of Titles, or null if the text doesn't contain a valid redirect
 395          * The last element in the array is the final destination after all redirects
 396          * have been resolved (up to $wgMaxRedirects times)
 397          *
 398          * @param $text String Text with possible redirect
 399          * @return Array of Titles, with the destination last
 400          */
 401         public static function newFromRedirectArray( $text ) {
 402                 global $wgMaxRedirects;
 403                 $title = self::newFromRedirectInternal( $text );
 404                 if ( is_null( $title ) ) {
 405                         return null;
 406                 }
 407                 // recursive check to follow double redirects
 408                 $recurse = $wgMaxRedirects;
 409                 $titles = array( $title );
 410                 while ( --$recurse > 0 ) {
 411                         if ( $title->isRedirect() ) {
 412                                 $page = WikiPage::factory( $title );
 413                                 $newtitle = $page->getRedirectTarget();
 414                         } else {
 415                                 break;
 416                         }
 417                         // Redirects to some special pages are not permitted
 418                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 419                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 420                                 $title = $newtitle;
 421                                 $titles[] = $newtitle;
 422                         } else {
 423                                 break;
 424                         }
 425                 }
 426                 return $titles;
 427         }
 428
 429         /**
 430          * Really extract the redirect destination
 431          * Do not call this function directly, use one of the newFromRedirect* functions above
 432          *
 433          * @param $text String Text with possible redirect
 434          * @return Title
 435          */
 436         protected static function newFromRedirectInternal( $text ) {
 437                 global $wgMaxRedirects;
 438                 if ( $wgMaxRedirects < 1 ) {
 439                         //redirects are disabled, so quit early
 440                         return null;
 441                 }
 442                 $redir = MagicWord::get( 'redirect' );
 443                 $text = trim( $text );
 444                 if ( $redir->matchStartAndRemove( $text ) ) {
 445                         // Extract the first link and see if it's usable
 446                         // Ensure that it really does come directly after #REDIRECT
 447                         // Some older redirects included a colon, so don't freak about that!
 448                         $m = array();
 449                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 450                                 // Strip preceding colon used to "escape" categories, etc.
 451                                 // and URL-decode links
 452                                 if ( strpos( $m[1], '%' ) !== false ) {
 453                                         // Match behavior of inline link parsing here;
 454                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 455                                 }
 456                                 $title = Title::newFromText( $m[1] );
 457                                 // If the title is a redirect to bad special pages or is invalid, return null
 458                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 459                                         return null;
 460                                 }
 461                                 return $title;
 462                         }
 463                 }
 464                 return null;
 465         }
 466
 467         /**
 468          * Get the prefixed DB key associated with an ID
 469          *
 470          * @param $id Int the page_id of the article
 471          * @return Title an object representing the article, or NULL if no such article was found
 472          */
 473         public static function nameOf( $id ) {
 474                 $dbr = wfGetDB( DB_SLAVE );
 475
 476                 $s = $dbr->selectRow(
 477                         'page',
 478                         array( 'page_namespace', 'page_title' ),
 479                         array( 'page_id' => $id ),
 480                         __METHOD__
 481                 );
 482                 if ( $s === false ) {
 483                         return null;
 484                 }
 485
 486                 $n = self::makeName( $s->page_namespace, $s->page_title );
 487                 return $n;
 488         }
 489
 490         /**
 491          * Get a regex character class describing the legal characters in a link
 492          *
 493          * @return String the list of characters, not delimited
 494          */
 495         public static function legalChars() {
 496                 global $wgLegalTitleChars;
 497                 return $wgLegalTitleChars;
 498         }
 499
 500         /**
 501          * Returns a simple regex that will match on characters and sequences invalid in titles.
 502          * Note that this doesn't pick up many things that could be wrong with titles, but that
 503          * replacing this regex with something valid will make many titles valid.
 504          *
 505          * @return String regex string
 506          */
 507         static function getTitleInvalidRegex() {
 508                 static $rxTc = false;
 509                 if ( !$rxTc ) {
 510                         # Matching titles will be held as illegal.
 511                         $rxTc = '/' .
 512                                 # Any character not allowed is forbidden...
 513                                 '[^' . self::legalChars() . ']' .
 514                                 # URL percent encoding sequences interfere with the ability
 515                                 # to round-trip titles -- you can't link to them consistently.
 516                                 '|%[0-9A-Fa-f]{2}' .
 517                                 # XML/HTML character references produce similar issues.
 518                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 519                                 '|&#[0-9]+;' .
 520                                 '|&#x[0-9A-Fa-f]+;' .
 521                                 '/S';
 522                 }
 523
 524                 return $rxTc;
 525         }
 526
 527         /**
 528          * Get a string representation of a title suitable for
 529          * including in a search index
 530          *
 531          * @param $ns Int a namespace index
 532          * @param $title String text-form main part
 533          * @return String a stripped-down title string ready for the search index
 534          */
 535         public static function indexTitle( $ns, $title ) {
 536                 global $wgContLang;
 537
 538                 $lc = SearchEngine::legalSearchChars() . '&#;';
 539                 $t = $wgContLang->normalizeForSearch( $title );
 540                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 541                 $t = $wgContLang->lc( $t );
 542
 543                 # Handle 's, s'
 544                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 545                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 546
 547                 $t = preg_replace( "/\\s+/", ' ', $t );
 548
 549                 if ( $ns == NS_FILE ) {
 550                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 551                 }
 552                 return trim( $t );
 553         }
 554
 555         /**
 556          * Make a prefixed DB key from a DB key and a namespace index
 557          *
 558          * @param $ns Int numerical representation of the namespace
 559          * @param $title String the DB key form the title
 560          * @param $fragment String The link fragment (after the "#")
 561          * @param $interwiki String The interwiki prefix
 562          * @return String the prefixed form of the title
 563          */
 564         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 565                 global $wgContLang;
 566
 567                 $namespace = $wgContLang->getNsText( $ns );
 568                 $name = $namespace == '' ? $title : "$namespace:$title";
 569                 if ( strval( $interwiki ) != '' ) {
 570                         $name = "$interwiki:$name";
 571                 }
 572                 if ( strval( $fragment ) != '' ) {
 573                         $name .= '#' . $fragment;
 574                 }
 575                 return $name;
 576         }
 577
 578         /**
 579          * Escape a text fragment, say from a link, for a URL
 580          *
 581          * @param $fragment string containing a URL or link fragment (after the "#")
 582          * @return String: escaped string
 583          */
 584         static function escapeFragmentForURL( $fragment ) {
 585                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 586                 # fragments appear not to work in IE (at least up to 7) or in at least
 587                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 588                 # to care if they aren't encoded.
 589                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 590         }
 591
 592         /**
 593          * Callback for usort() to do title sorts by (namespace, title)
 594          *
 595          * @param $a Title
 596          * @param $b Title
 597          *
 598          * @return Integer: result of string comparison, or namespace comparison
 599          */
 600         public static function compare( $a, $b ) {
 601                 if ( $a->getNamespace() == $b->getNamespace() ) {
 602                         return strcmp( $a->getText(), $b->getText() );
 603                 } else {
 604                         return $a->getNamespace() - $b->getNamespace();
 605                 }
 606         }
 607
 608         /**
 609          * Determine whether the object refers to a page within
 610          * this project.
 611          *
 612          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 613          */
 614         public function isLocal() {
 615                 if ( $this->mInterwiki != '' ) {
 616                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 617                 } else {
 618                         return true;
 619                 }
 620         }
 621
 622         /**
 623          * Is this Title interwiki?
 624          *
 625          * @return Bool
 626          */
 627         public function isExternal() {
 628                 return ( $this->mInterwiki != '' );
 629         }
 630
 631         /**
 632          * Get the interwiki prefix (or null string)
 633          *
 634          * @return String Interwiki prefix
 635          */
 636         public function getInterwiki() {
 637                 return $this->mInterwiki;
 638         }
 639
 640         /**
 641          * Determine whether the object refers to a page within
 642          * this project and is transcludable.
 643          *
 644          * @return Bool TRUE if this is transcludable
 645          */
 646         public function isTrans() {
 647                 if ( $this->mInterwiki == '' ) {
 648                         return false;
 649                 }
 650
 651                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 652         }
 653
 654         /**
 655          * Returns the DB name of the distant wiki which owns the object.
 656          *
 657          * @return String the DB name
 658          */
 659         public function getTransWikiID() {
 660                 if ( $this->mInterwiki == '' ) {
 661                         return false;
 662                 }
 663
 664                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 665         }
 666
 667         /**
 668          * Get the text form (spaces not underscores) of the main part
 669          *
 670          * @return String Main part of the title
 671          */
 672         public function getText() {
 673                 return $this->mTextform;
 674         }
 675
 676         /**
 677          * Get the URL-encoded form of the main part
 678          *
 679          * @return String Main part of the title, URL-encoded
 680          */
 681         public function getPartialURL() {
 682                 return $this->mUrlform;
 683         }
 684
 685         /**
 686          * Get the main part with underscores
 687          *
 688          * @return String: Main part of the title, with underscores
 689          */
 690         public function getDBkey() {
 691                 return $this->mDbkeyform;
 692         }
 693
 694         /**
 695          * Get the DB key with the initial letter case as specified by the user
 696          *
 697          * @return String DB key
 698          */
 699         function getUserCaseDBKey() {
 700                 return $this->mUserCaseDBKey;
 701         }
 702
 703         /**
 704          * Get the namespace index, i.e. one of the NS_xxxx constants.
 705          *
 706          * @return Integer: Namespace index
 707          */
 708         public function getNamespace() {
 709                 return $this->mNamespace;
 710         }
 711
 712         /**
 713          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 714          *
 715          * @return Integer: Content model id
 716          */
 717         public function getContentModel() {
 718                 if ( empty( $this->mContentModel ) ) {
 719                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 720                 }
 721
 722                 assert( !empty( $this->mContentModel ) );
 723                 return $this->mContentModel;
 724         }
 725
 726         /**
 727          * Convenience method for checking a title's content model name
 728          *
 729          * @param int $id
 730          * @return true if $this->getContentModel() == $id
 731          */
 732         public function hasContentModel( $id ) {
 733                 return $this->getContentModel() == $id;
 734         }
 735
 736         /**
 737          * Get the namespace text
 738          *
 739          * @return String: Namespace text
 740          */
 741         public function getNsText() {
 742                 global $wgContLang;
 743
 744                 if ( $this->mInterwiki != '' ) {
 745                         // This probably shouldn't even happen. ohh man, oh yuck.
 746                         // But for interwiki transclusion it sometimes does.
 747                         // Shit. Shit shit shit.
 748                         //
 749                         // Use the canonical namespaces if possible to try to
 750                         // resolve a foreign namespace.
 751                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 752                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 753                         }
 754                 }
 755
 756                 if ( $wgContLang->needsGenderDistinction() &&
 757                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 758                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 759                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 760                 }
 761
 762                 return $wgContLang->getNsText( $this->mNamespace );
 763         }
 764
 765         /**
 766          * Get the namespace text of the subject (rather than talk) page
 767          *
 768          * @return String Namespace text
 769          */
 770         public function getSubjectNsText() {
 771                 global $wgContLang;
 772                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 773         }
 774
 775         /**
 776          * Get the namespace text of the talk page
 777          *
 778          * @return String Namespace text
 779          */
 780         public function getTalkNsText() {
 781                 global $wgContLang;
 782                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 783         }
 784
 785         /**
 786          * Could this title have a corresponding talk page?
 787          *
 788          * @return Bool TRUE or FALSE
 789          */
 790         public function canTalk() {
 791                 return( MWNamespace::canTalk( $this->mNamespace ) );
 792         }
 793
 794         /**
 795          * Is this in a namespace that allows actual pages?
 796          *
 797          * @return Bool
 798          * @internal note -- uses hardcoded namespace index instead of constants
 799          */
 800         public function canExist() {
 801                 return $this->mNamespace >= NS_MAIN;
 802         }
 803
 804         /**
 805          * Can this title be added to a user's watchlist?
 806          *
 807          * @return Bool TRUE or FALSE
 808          */
 809         public function isWatchable() {
 810                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 811         }
 812
 813         /**
 814          * Returns true if this is a special page.
 815          *
 816          * @return boolean
 817          */
 818         public function isSpecialPage() {
 819                 return $this->getNamespace() == NS_SPECIAL;
 820         }
 821
 822         /**
 823          * Returns true if this title resolves to the named special page
 824          *
 825          * @param $name String The special page name
 826          * @return boolean
 827          */
 828         public function isSpecial( $name ) {
 829                 if ( $this->isSpecialPage() ) {
 830                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 831                         if ( $name == $thisName ) {
 832                                 return true;
 833                         }
 834                 }
 835                 return false;
 836         }
 837
 838         /**
 839          * If the Title refers to a special page alias which is not the local default, resolve
 840          * the alias, and localise the name as necessary.  Otherwise, return $this
 841          *
 842          * @return Title
 843          */
 844         public function fixSpecialName() {
 845                 if ( $this->isSpecialPage() ) {
 846                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 847                         if ( $canonicalName ) {
 848                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 849                                 if ( $localName != $this->mDbkeyform ) {
 850                                         return Title::makeTitle( NS_SPECIAL, $localName );
 851                                 }
 852                         }
 853                 }
 854                 return $this;
 855         }
 856
 857         /**
 858          * Returns true if the title is inside the specified namespace.
 859          *
 860          * Please make use of this instead of comparing to getNamespace()
 861          * This function is much more resistant to changes we may make
 862          * to namespaces than code that makes direct comparisons.
 863          * @param $ns int The namespace
 864          * @return bool
 865          * @since 1.19
 866          */
 867         public function inNamespace( $ns ) {
 868                 return MWNamespace::equals( $this->getNamespace(), $ns );
 869         }
 870
 871         /**
 872          * Returns true if the title is inside one of the specified namespaces.
 873          *
 874          * @param ...$namespaces The namespaces to check for
 875          * @return bool
 876          * @since 1.19
 877          */
 878         public function inNamespaces( /* ... */ ) {
 879                 $namespaces = func_get_args();
 880                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 881                         $namespaces = $namespaces[0];
 882                 }
 883
 884                 foreach ( $namespaces as $ns ) {
 885                         if ( $this->inNamespace( $ns ) ) {
 886                                 return true;
 887                         }
 888                 }
 889
 890                 return false;
 891         }
 892
 893         /**
 894          * Returns true if the title has the same subject namespace as the
 895          * namespace specified.
 896          * For example this method will take NS_USER and return true if namespace
 897          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 898          * as their subject namespace.
 899          *
 900          * This is MUCH simpler than individually testing for equivilance
 901          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 902          * @since 1.19
 903          * @param $ns int
 904          * @return bool
 905          */
 906         public function hasSubjectNamespace( $ns ) {
 907                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 908         }
 909
 910         /**
 911          * Is this Title in a namespace which contains content?
 912          * In other words, is this a content page, for the purposes of calculating
 913          * statistics, etc?
 914          *
 915          * @return Boolean
 916          */
 917         public function isContentPage() {
 918                 return MWNamespace::isContent( $this->getNamespace() );
 919         }
 920
 921         /**
 922          * Would anybody with sufficient privileges be able to move this page?
 923          * Some pages just aren't movable.
 924          *
 925          * @return Bool TRUE or FALSE
 926          */
 927         public function isMovable() {
 928                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 929                         // Interwiki title or immovable namespace. Hooks don't get to override here
 930                         return false;
 931                 }
 932
 933                 $result = true;
 934                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 935                 return $result;
 936         }
 937
 938         /**
 939          * Is this the mainpage?
 940          * @note Title::newFromText seams to be sufficiently optimized by the title
 941          * cache that we don't need to over-optimize by doing direct comparisons and
 942          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 943          * ends up reporting something differently than $title->isMainPage();
 944          *
 945          * @since 1.18
 946          * @return Bool
 947          */
 948         public function isMainPage() {
 949                 return $this->equals( Title::newMainPage() );
 950         }
 951
 952         /**
 953          * Is this a subpage?
 954          *
 955          * @return Bool
 956          */
 957         public function isSubpage() {
 958                 return MWNamespace::hasSubpages( $this->mNamespace )
 959                         ? strpos( $this->getText(), '/' ) !== false
 960                         : false;
 961         }
 962
 963         /**
 964          * Is this a conversion table for the LanguageConverter?
 965          *
 966          * @return Bool
 967          */
 968         public function isConversionTable() {
 969                 return $this->getNamespace() == NS_MEDIAWIKI &&
 970                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 971         }
 972
 973         /**
 974          * Does that page contain wikitext, or it is JS, CSS or whatever?
 975          *
 976          * @return Bool
 977          */
 978         public function isWikitextPage() {
 979                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 980         }
 981
 982         /**
 983          * Could this page contain custom CSS or JavaScript for the global UI.
 984          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 985          * or CONTENT_MODEL_JAVASCRIPT.
 986          *
 987          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
 988          *
 989          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 990          *
 991          * @return Bool
 992          */
 993         public function isCssOrJsPage() {
 994                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 995                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 996                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 997
 998                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 999                 #      hook funktions can force this method to return true even outside the mediawiki namespace.
1000
1001                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
1002
1003                 return $isCssOrJsPage;
1004         }
1005
1006         /**
1007          * Is this a .css or .js subpage of a user page?
1008          * @return Bool
1009          */
1010         public function isCssJsSubpage() {
1011                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1012                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1013                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1014         }
1015
1016         /**
1017          * Trim down a .css or .js subpage title to get the corresponding skin name
1018          *
1019          * @return string containing skin name from .css or .js subpage title
1020          */
1021         public function getSkinFromCssJsSubpage() {
1022                 $subpage = explode( '/', $this->mTextform );
1023                 $subpage = $subpage[ count( $subpage ) - 1 ];
1024                 $lastdot = strrpos( $subpage, '.' );
1025                 if ( $lastdot === false )
1026                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1027                 return substr( $subpage, 0, $lastdot );
1028         }
1029
1030         /**
1031          * Is this a .css subpage of a user page?
1032          *
1033          * @return Bool
1034          */
1035         public function isCssSubpage() {
1036                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1037                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1038         }
1039
1040         /**
1041          * Is this a .js subpage of a user page?
1042          *
1043          * @return Bool
1044          */
1045         public function isJsSubpage() {
1046                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1047                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1048         }
1049
1050         /**
1051          * Is this a talk page of some sort?
1052          *
1053          * @return Bool
1054          */
1055         public function isTalkPage() {
1056                 return MWNamespace::isTalk( $this->getNamespace() );
1057         }
1058
1059         /**
1060          * Get a Title object associated with the talk page of this article
1061          *
1062          * @return Title the object for the talk page
1063          */
1064         public function getTalkPage() {
1065                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1066         }
1067
1068         /**
1069          * Get a title object associated with the subject page of this
1070          * talk page
1071          *
1072          * @return Title the object for the subject page
1073          */
1074         public function getSubjectPage() {
1075                 // Is this the same title?
1076                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1077                 if ( $this->getNamespace() == $subjectNS ) {
1078                         return $this;
1079                 }
1080                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1081         }
1082
1083         /**
1084          * Get the default namespace index, for when there is no namespace
1085          *
1086          * @return Int Default namespace index
1087          */
1088         public function getDefaultNamespace() {
1089                 return $this->mDefaultNamespace;
1090         }
1091
1092         /**
1093          * Get title for search index
1094          *
1095          * @return String a stripped-down title string ready for the
1096          *  search index
1097          */
1098         public function getIndexTitle() {
1099                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1100         }
1101
1102         /**
1103          * Get the Title fragment (i.e.\ the bit after the #) in text form
1104          *
1105          * @return String Title fragment
1106          */
1107         public function getFragment() {
1108                 return $this->mFragment;
1109         }
1110
1111         /**
1112          * Get the fragment in URL form, including the "#" character if there is one
1113          * @return String Fragment in URL form
1114          */
1115         public function getFragmentForURL() {
1116                 if ( $this->mFragment == '' ) {
1117                         return '';
1118                 } else {
1119                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1120                 }
1121         }
1122
1123         /**
1124          * Set the fragment for this title. Removes the first character from the
1125          * specified fragment before setting, so it assumes you're passing it with
1126          * an initial "#".
1127          *
1128          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1129          * Still in active use privately.
1130          *
1131          * @param $fragment String text
1132          */
1133         public function setFragment( $fragment ) {
1134                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1135         }
1136
1137         /**
1138          * Prefix some arbitrary text with the namespace or interwiki prefix
1139          * of this object
1140          *
1141          * @param $name String the text
1142          * @return String the prefixed text
1143          * @private
1144          */
1145         private function prefix( $name ) {
1146                 $p = '';
1147                 if ( $this->mInterwiki != '' ) {
1148                         $p = $this->mInterwiki . ':';
1149                 }
1150
1151                 if ( 0 != $this->mNamespace ) {
1152                         $p .= $this->getNsText() . ':';
1153                 }
1154                 return $p . $name;
1155         }
1156
1157         /**
1158          * Get the prefixed database key form
1159          *
1160          * @return String the prefixed title, with underscores and
1161          *  any interwiki and namespace prefixes
1162          */
1163         public function getPrefixedDBkey() {
1164                 $s = $this->prefix( $this->mDbkeyform );
1165                 $s = str_replace( ' ', '_', $s );
1166                 return $s;
1167         }
1168
1169         /**
1170          * Get the prefixed title with spaces.
1171          * This is the form usually used for display
1172          *
1173          * @return String the prefixed title, with spaces
1174          */
1175         public function getPrefixedText() {
1176                 // @todo FIXME: Bad usage of empty() ?
1177                 if ( empty( $this->mPrefixedText ) ) {
1178                         $s = $this->prefix( $this->mTextform );
1179                         $s = str_replace( '_', ' ', $s );
1180                         $this->mPrefixedText = $s;
1181                 }
1182                 return $this->mPrefixedText;
1183         }
1184
1185         /**
1186          * Return a string representation of this title
1187          *
1188          * @return String representation of this title
1189          */
1190         public function __toString() {
1191                 return $this->getPrefixedText();
1192         }
1193
1194         /**
1195          * Get the prefixed title with spaces, plus any fragment
1196          * (part beginning with '#')
1197          *
1198          * @return String the prefixed title, with spaces and the fragment, including '#'
1199          */
1200         public function getFullText() {
1201                 $text = $this->getPrefixedText();
1202                 if ( $this->mFragment != '' ) {
1203                         $text .= '#' . $this->mFragment;
1204                 }
1205                 return $text;
1206         }
1207
1208         /**
1209          * Get the base page name, i.e. the leftmost part before any slashes
1210          *
1211          * @return String Base name
1212          */
1213         public function getBaseText() {
1214                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1215                         return $this->getText();
1216                 }
1217
1218                 $parts = explode( '/', $this->getText() );
1219                 # Don't discard the real title if there's no subpage involved
1220                 if ( count( $parts ) > 1 ) {
1221                         unset( $parts[count( $parts ) - 1] );
1222                 }
1223                 return implode( '/', $parts );
1224         }
1225
1226         /**
1227          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1228          *
1229          * @return String Subpage name
1230          */
1231         public function getSubpageText() {
1232                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1233                         return( $this->mTextform );
1234                 }
1235                 $parts = explode( '/', $this->mTextform );
1236                 return( $parts[count( $parts ) - 1] );
1237         }
1238
1239         /**
1240          * Get the HTML-escaped displayable text form.
1241          * Used for the title field in <a> tags.
1242          *
1243          * @return String the text, including any prefixes
1244          */
1245         public function getEscapedText() {
1246                 wfDeprecated( __METHOD__, '1.19' );
1247                 return htmlspecialchars( $this->getPrefixedText() );
1248         }
1249
1250         /**
1251          * Get a URL-encoded form of the subpage text
1252          *
1253          * @return String URL-encoded subpage name
1254          */
1255         public function getSubpageUrlForm() {
1256                 $text = $this->getSubpageText();
1257                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1258                 return( $text );
1259         }
1260
1261         /**
1262          * Get a URL-encoded title (not an actual URL) including interwiki
1263          *
1264          * @return String the URL-encoded form
1265          */
1266         public function getPrefixedURL() {
1267                 $s = $this->prefix( $this->mDbkeyform );
1268                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1269                 return $s;
1270         }
1271
1272         /**
1273          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1274          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1275          * second argument named variant. This was deprecated in favor
1276          * of passing an array of option with a "variant" key
1277          * Once $query2 is removed for good, this helper can be dropped
1278          * andthe wfArrayToCGI moved to getLocalURL();
1279          *
1280          * @since 1.19 (r105919)
1281          * @param $query
1282          * @param $query2 bool
1283          * @return String
1284          */
1285         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1286                 if( $query2 !== false ) {
1287                         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" );
1288                 }
1289                 if ( is_array( $query ) ) {
1290                         $query = wfArrayToCGI( $query );
1291                 }
1292                 if ( $query2 ) {
1293                         if ( is_string( $query2 ) ) {
1294                                 // $query2 is a string, we will consider this to be
1295                                 // a deprecated $variant argument and add it to the query
1296                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1297                         } else {
1298                                 $query2 = wfArrayToCGI( $query2 );
1299                         }
1300                         // If we have $query content add a & to it first
1301                         if ( $query ) {
1302                                 $query .= '&';
1303                         }
1304                         // Now append the queries together
1305                         $query .= $query2;
1306                 }
1307                 return $query;
1308         }
1309
1310         /**
1311          * Get a real URL referring to this title, with interwiki link and
1312          * fragment
1313          *
1314          * See getLocalURL for the arguments.
1315          *
1316          * @see self::getLocalURL
1317          * @return String the URL
1318          */
1319         public function getFullURL( $query = '', $query2 = false ) {
1320                 $query = self::fixUrlQueryArgs( $query, $query2 );
1321
1322                 # Hand off all the decisions on urls to getLocalURL
1323                 $url = $this->getLocalURL( $query );
1324
1325                 # Expand the url to make it a full url. Note that getLocalURL has the
1326                 # potential to output full urls for a variety of reasons, so we use
1327                 # wfExpandUrl instead of simply prepending $wgServer
1328                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1329
1330                 # Finally, add the fragment.
1331                 $url .= $this->getFragmentForURL();
1332
1333                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1334                 return $url;
1335         }
1336
1337         /**
1338          * Get a URL with no fragment or server name.  If this page is generated
1339          * with action=render, $wgServer is prepended.
1340          *
1341
1342          * @param $query string|array an optional query string,
1343          *   not used for interwiki     links. Can be specified as an associative array as well,
1344          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1345          *   Some query patterns will trigger various shorturl path replacements.
1346          * @param $query2 Mixed: An optional secondary query array. This one MUST
1347          *   be an array. If a string is passed it will be interpreted as a deprecated
1348          *   variant argument and urlencoded into a variant= argument.
1349          *   This second query argument will be added to the $query
1350          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1351          *   pair in the first parameter array instead.
1352          *
1353          * @return String the URL
1354          */
1355         public function getLocalURL( $query = '', $query2 = false ) {
1356                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1357
1358                 $query = self::fixUrlQueryArgs( $query, $query2 );
1359
1360                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1361                 if ( $interwiki ) {
1362                         $namespace = $this->getNsText();
1363                         if ( $namespace != '' ) {
1364                                 # Can this actually happen? Interwikis shouldn't be parsed.
1365                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1366                                 $namespace .= ':';
1367                         }
1368                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1369                         $url = wfAppendQuery( $url, $query );
1370                 } else {
1371                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1372                         if ( $query == '' ) {
1373                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1374                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1375                         } else {
1376                                 global $wgVariantArticlePath, $wgActionPaths;
1377                                 $url = false;
1378                                 $matches = array();
1379
1380                                 if ( !empty( $wgActionPaths ) &&
1381                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1382                                 {
1383                                         $action = urldecode( $matches[2] );
1384                                         if ( isset( $wgActionPaths[$action] ) ) {
1385                                                 $query = $matches[1];
1386                                                 if ( isset( $matches[4] ) ) {
1387                                                         $query .= $matches[4];
1388                                                 }
1389                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1390                                                 if ( $query != '' ) {
1391                                                         $url = wfAppendQuery( $url, $query );
1392                                                 }
1393                                         }
1394                                 }
1395
1396                                 if ( $url === false &&
1397                                         $wgVariantArticlePath &&
1398                                         $this->getPageLanguage()->hasVariants() &&
1399                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1400                                 {
1401                                         $variant = urldecode( $matches[1] );
1402                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1403                                                 // Only do the variant replacement if the given variant is a valid
1404                                                 // variant for the page's language.
1405                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1406                                                 $url = str_replace( '$1', $dbkey, $url );
1407                                         }
1408                                 }
1409
1410                                 if ( $url === false ) {
1411                                         if ( $query == '-' ) {
1412                                                 $query = '';
1413                                         }
1414                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1415                                 }
1416                         }
1417
1418                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1419
1420                         // @todo FIXME: This causes breakage in various places when we
1421                         // actually expected a local URL and end up with dupe prefixes.
1422                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1423                                 $url = $wgServer . $url;
1424                         }
1425                 }
1426                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1427                 return $url;
1428         }
1429
1430         /**
1431          * Get a URL that's the simplest URL that will be valid to link, locally,
1432          * to the current Title.  It includes the fragment, but does not include
1433          * the server unless action=render is used (or the link is external).  If
1434          * there's a fragment but the prefixed text is empty, we just return a link
1435          * to the fragment.
1436          *
1437          * The result obviously should not be URL-escaped, but does need to be
1438          * HTML-escaped if it's being output in HTML.
1439          *
1440          * See getLocalURL for the arguments.
1441          *
1442          * @see self::getLocalURL
1443          * @return String the URL
1444          */
1445         public function getLinkURL( $query = '', $query2 = false ) {
1446                 wfProfileIn( __METHOD__ );
1447                 if ( $this->isExternal() ) {
1448                         $ret = $this->getFullURL( $query, $query2 );
1449                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1450                         $ret = $this->getFragmentForURL();
1451                 } else {
1452                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1453                 }
1454                 wfProfileOut( __METHOD__ );
1455                 return $ret;
1456         }
1457
1458         /**
1459          * Get an HTML-escaped version of the URL form, suitable for
1460          * using in a link, without a server name or fragment
1461          *
1462          * See getLocalURL for the arguments.
1463          *
1464          * @see self::getLocalURL
1465          * @param $query string
1466          * @param $query2 bool|string
1467          * @return String the URL
1468          */
1469         public function escapeLocalURL( $query = '', $query2 = false ) {
1470                 wfDeprecated( __METHOD__, '1.19' );
1471                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1472         }
1473
1474         /**
1475          * Get an HTML-escaped version of the URL form, suitable for
1476          * using in a link, including the server name and fragment
1477          *
1478          * See getLocalURL for the arguments.
1479          *
1480          * @see self::getLocalURL
1481          * @return String the URL
1482          */
1483         public function escapeFullURL( $query = '', $query2 = false ) {
1484                 wfDeprecated( __METHOD__, '1.19' );
1485                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1486         }
1487
1488         /**
1489          * Get the URL form for an internal link.
1490          * - Used in various Squid-related code, in case we have a different
1491          * internal hostname for the server from the exposed one.
1492          *
1493          * This uses $wgInternalServer to qualify the path, or $wgServer
1494          * if $wgInternalServer is not set. If the server variable used is
1495          * protocol-relative, the URL will be expanded to http://
1496          *
1497          * See getLocalURL for the arguments.
1498          *
1499          * @see self::getLocalURL
1500          * @return String the URL
1501          */
1502         public function getInternalURL( $query = '', $query2 = false ) {
1503                 global $wgInternalServer, $wgServer;
1504                 $query = self::fixUrlQueryArgs( $query, $query2 );
1505                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1506                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1507                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1508                 return $url;
1509         }
1510
1511         /**
1512          * Get the URL for a canonical link, for use in things like IRC and
1513          * e-mail notifications. Uses $wgCanonicalServer and the
1514          * GetCanonicalURL hook.
1515          *
1516          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1517          *
1518          * See getLocalURL for the arguments.
1519          *
1520          * @see self::getLocalURL
1521          * @return string The URL
1522          * @since 1.18
1523          */
1524         public function getCanonicalURL( $query = '', $query2 = false ) {
1525                 $query = self::fixUrlQueryArgs( $query, $query2 );
1526                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1527                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1528                 return $url;
1529         }
1530
1531         /**
1532          * HTML-escaped version of getCanonicalURL()
1533          *
1534          * See getLocalURL for the arguments.
1535          *
1536          * @see self::getLocalURL
1537          * @since 1.18
1538          * @return string
1539          */
1540         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1541                 wfDeprecated( __METHOD__, '1.19' );
1542                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1543         }
1544
1545         /**
1546          * Get the edit URL for this Title
1547          *
1548          * @return String the URL, or a null string if this is an
1549          *  interwiki link
1550          */
1551         public function getEditURL() {
1552                 if ( $this->mInterwiki != '' ) {
1553                         return '';
1554                 }
1555                 $s = $this->getLocalURL( 'action=edit' );
1556
1557                 return $s;
1558         }
1559
1560         /**
1561          * Is $wgUser watching this page?
1562          *
1563          * @return Bool
1564          */
1565         public function userIsWatching() {
1566                 global $wgUser;
1567
1568                 if ( is_null( $this->mWatched ) ) {
1569                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1570                                 $this->mWatched = false;
1571                         } else {
1572                                 $this->mWatched = $wgUser->isWatched( $this );
1573                         }
1574                 }
1575                 return $this->mWatched;
1576         }
1577
1578         /**
1579          * Can $wgUser read this page?
1580          *
1581          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1582          * @return Bool
1583          * @todo fold these checks into userCan()
1584          */
1585         public function userCanRead() {
1586                 wfDeprecated( __METHOD__, '1.19' );
1587                 return $this->userCan( 'read' );
1588         }
1589
1590         /**
1591          * Can $user perform $action on this page?
1592          * This skips potentially expensive cascading permission checks
1593          * as well as avoids expensive error formatting
1594          *
1595          * Suitable for use for nonessential UI controls in common cases, but
1596          * _not_ for functional access control.
1597          *
1598          * May provide false positives, but should never provide a false negative.
1599          *
1600          * @param $action String action that permission needs to be checked for
1601          * @param $user User to check (since 1.19); $wgUser will be used if not
1602          *              provided.
1603          * @return Bool
1604          */
1605         public function quickUserCan( $action, $user = null ) {
1606                 return $this->userCan( $action, $user, false );
1607         }
1608
1609         /**
1610          * Can $user perform $action on this page?
1611          *
1612          * @param $action String action that permission needs to be checked for
1613          * @param $user User to check (since 1.19); $wgUser will be used if not
1614          *   provided.
1615          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1616          *   unnecessary queries.
1617          * @return Bool
1618          */
1619         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1620                 if ( !$user instanceof User ) {
1621                         global $wgUser;
1622                         $user = $wgUser;
1623                 }
1624                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1625         }
1626
1627         /**
1628          * Can $user perform $action on this page?
1629          *
1630          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1631          *
1632          * @param $action String action that permission needs to be checked for
1633          * @param $user User to check
1634          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1635          *   queries by skipping checks for cascading protections and user blocks.
1636          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1637          *   whose corresponding errors may be ignored.
1638          * @return Array of arguments to wfMsg to explain permissions problems.
1639          */
1640         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1641                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1642
1643                 // Remove the errors being ignored.
1644                 foreach ( $errors as $index => $error ) {
1645                         $error_key = is_array( $error ) ? $error[0] : $error;
1646
1647                         if ( in_array( $error_key, $ignoreErrors ) ) {
1648                                 unset( $errors[$index] );
1649                         }
1650                 }
1651
1652                 return $errors;
1653         }
1654
1655         /**
1656          * Permissions checks that fail most often, and which are easiest to test.
1657          *
1658          * @param $action String the action to check
1659          * @param $user User user to check
1660          * @param $errors Array list of current errors
1661          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1662          * @param $short Boolean short circuit on first error
1663          *
1664          * @return Array list of errors
1665          */
1666         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1667                 if ( $action == 'create' ) {
1668                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1669                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1670                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1671                         }
1672                 } elseif ( $action == 'move' ) {
1673                         if ( !$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-user-page' );
1677                         }
1678
1679                         // Check if user is allowed to move files if it's a file
1680                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1681                                 $errors[] = array( 'movenotallowedfile' );
1682                         }
1683
1684                         if ( !$user->isAllowed( 'move' ) ) {
1685                                 // User can't move anything
1686                                 global $wgGroupPermissions;
1687                                 $userCanMove = false;
1688                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1689                                         $userCanMove = $wgGroupPermissions['user']['move'];
1690                                 }
1691                                 $autoconfirmedCanMove = false;
1692                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1693                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1694                                 }
1695                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1696                                         // custom message if logged-in users without any special rights can move
1697                                         $errors[] = array( 'movenologintext' );
1698                                 } else {
1699                                         $errors[] = array( 'movenotallowed' );
1700                                 }
1701                         }
1702                 } elseif ( $action == 'move-target' ) {
1703                         if ( !$user->isAllowed( 'move' ) ) {
1704                                 // User can't move anything
1705                                 $errors[] = array( 'movenotallowed' );
1706                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1707                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1708                                 // Show user page-specific message only if the user can move other pages
1709                                 $errors[] = array( 'cant-move-to-user-page' );
1710                         }
1711                 } elseif ( !$user->isAllowed( $action ) ) {
1712                         $errors[] = $this->missingPermissionError( $action, $short );
1713                 }
1714
1715                 return $errors;
1716         }
1717
1718         /**
1719          * Add the resulting error code to the errors array
1720          *
1721          * @param $errors Array list of current errors
1722          * @param $result Mixed result of errors
1723          *
1724          * @return Array list of errors
1725          */
1726         private function resultToError( $errors, $result ) {
1727                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1728                         // A single array representing an error
1729                         $errors[] = $result;
1730                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1731                         // A nested array representing multiple errors
1732                         $errors = array_merge( $errors, $result );
1733                 } elseif ( $result !== '' && is_string( $result ) ) {
1734                         // A string representing a message-id
1735                         $errors[] = array( $result );
1736                 } elseif ( $result === false ) {
1737                         // a generic "We don't want them to do that"
1738                         $errors[] = array( 'badaccess-group0' );
1739                 }
1740                 return $errors;
1741         }
1742
1743         /**
1744          * Check various permission hooks
1745          *
1746          * @param $action String the action to check
1747          * @param $user User user to check
1748          * @param $errors Array list of current errors
1749          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1750          * @param $short Boolean short circuit on first error
1751          *
1752          * @return Array list of errors
1753          */
1754         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1755                 // Use getUserPermissionsErrors instead
1756                 $result = '';
1757                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1758                         return $result ? array() : array( array( 'badaccess-group0' ) );
1759                 }
1760                 // Check getUserPermissionsErrors hook
1761                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1762                         $errors = $this->resultToError( $errors, $result );
1763                 }
1764                 // Check getUserPermissionsErrorsExpensive hook
1765                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1766                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1767                         $errors = $this->resultToError( $errors, $result );
1768                 }
1769
1770                 return $errors;
1771         }
1772
1773         /**
1774          * Check permissions on special pages & namespaces
1775          *
1776          * @param $action String the action to check
1777          * @param $user User user to check
1778          * @param $errors Array list of current errors
1779          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1780          * @param $short Boolean short circuit on first error
1781          *
1782          * @return Array list of errors
1783          */
1784         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1785                 # Only 'createaccount' and 'execute' can be performed on
1786                 # special pages, which don't actually exist in the DB.
1787                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1788                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1789                         $errors[] = array( 'ns-specialprotected' );
1790                 }
1791
1792                 # Check $wgNamespaceProtection for restricted namespaces
1793                 if ( $this->isNamespaceProtected( $user ) ) {
1794                         $ns = $this->mNamespace == NS_MAIN ?
1795                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1796                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1797                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1798                 }
1799
1800                 return $errors;
1801         }
1802
1803         /**
1804          * Check CSS/JS sub-page permissions
1805          *
1806          * @param $action String the action to check
1807          * @param $user User user to check
1808          * @param $errors Array list of current errors
1809          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1810          * @param $short Boolean short circuit on first error
1811          *
1812          * @return Array list of errors
1813          */
1814         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1815                 # Protect css/js subpages of user pages
1816                 # XXX: this might be better using restrictions
1817                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1818                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1819                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1820                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1821                                 $errors[] = array( 'customcssprotected' );
1822                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1823                                 $errors[] = array( 'customjsprotected' );
1824                         }
1825                 }
1826
1827                 return $errors;
1828         }
1829
1830         /**
1831          * Check against page_restrictions table requirements on this
1832          * page. The user must possess all required rights for this
1833          * action.
1834          *
1835          * @param $action String the action to check
1836          * @param $user User user to check
1837          * @param $errors Array list of current errors
1838          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1839          * @param $short Boolean short circuit on first error
1840          *
1841          * @return Array list of errors
1842          */
1843         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1844                 foreach ( $this->getRestrictions( $action ) as $right ) {
1845                         // Backwards compatibility, rewrite sysop -> protect
1846                         if ( $right == 'sysop' ) {
1847                                 $right = 'protect';
1848                         }
1849                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1850                                 // Users with 'editprotected' permission can edit protected pages
1851                                 // without cascading option turned on.
1852                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1853                                         || $this->mCascadeRestriction )
1854                                 {
1855                                         $errors[] = array( 'protectedpagetext', $right );
1856                                 }
1857                         }
1858                 }
1859
1860                 return $errors;
1861         }
1862
1863         /**
1864          * Check restrictions on cascading pages.
1865          *
1866          * @param $action String the action to check
1867          * @param $user User to check
1868          * @param $errors Array list of current errors
1869          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1870          * @param $short Boolean short circuit on first error
1871          *
1872          * @return Array list of errors
1873          */
1874         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1875                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1876                         # We /could/ use the protection level on the source page, but it's
1877                         # fairly ugly as we have to establish a precedence hierarchy for pages
1878                         # included by multiple cascade-protected pages. So just restrict
1879                         # it to people with 'protect' permission, as they could remove the
1880                         # protection anyway.
1881                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1882                         # Cascading protection depends on more than this page...
1883                         # Several cascading protected pages may include this page...
1884                         # Check each cascading level
1885                         # This is only for protection restrictions, not for all actions
1886                         if ( isset( $restrictions[$action] ) ) {
1887                                 foreach ( $restrictions[$action] as $right ) {
1888                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1889                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1890                                                 $pages = '';
1891                                                 foreach ( $cascadingSources as $page )
1892                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1893                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1894                                         }
1895                                 }
1896                         }
1897                 }
1898
1899                 return $errors;
1900         }
1901
1902         /**
1903          * Check action permissions not already checked in checkQuickPermissions
1904          *
1905          * @param $action String the action to check
1906          * @param $user User to check
1907          * @param $errors Array list of current errors
1908          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1909          * @param $short Boolean short circuit on first error
1910          *
1911          * @return Array list of errors
1912          */
1913         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1914                 global $wgDeleteRevisionsLimit, $wgLang;
1915
1916                 if ( $action == 'protect' ) {
1917                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1918                                 // If they can't edit, they shouldn't protect.
1919                                 $errors[] = array( 'protect-cantedit' );
1920                         }
1921                 } elseif ( $action == 'create' ) {
1922                         $title_protection = $this->getTitleProtection();
1923                         if( $title_protection ) {
1924                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1925                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1926                                 }
1927                                 if( $title_protection['pt_create_perm'] == '' ||
1928                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1929                                 {
1930                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1931                                 }
1932                         }
1933                 } elseif ( $action == 'move' ) {
1934                         // Check for immobile pages
1935                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1936                                 // Specific message for this case
1937                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1938                         } elseif ( !$this->isMovable() ) {
1939                                 // Less specific message for rarer cases
1940                                 $errors[] = array( 'immobile-source-page' );
1941                         }
1942                 } elseif ( $action == 'move-target' ) {
1943                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1944                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1945                         } elseif ( !$this->isMovable() ) {
1946                                 $errors[] = array( 'immobile-target-page' );
1947                         }
1948                 } elseif ( $action == 'delete' ) {
1949                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1950                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1951                         {
1952                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1953                         }
1954                 }
1955                 return $errors;
1956         }
1957
1958         /**
1959          * Check that the user isn't blocked from editting.
1960          *
1961          * @param $action String the action to check
1962          * @param $user User to check
1963          * @param $errors Array list of current errors
1964          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1965          * @param $short Boolean short circuit on first error
1966          *
1967          * @return Array list of errors
1968          */
1969         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1970                 // Account creation blocks handled at userlogin.
1971                 // Unblocking handled in SpecialUnblock
1972                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1973                         return $errors;
1974                 }
1975
1976                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1977
1978                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1979                         $errors[] = array( 'confirmedittext' );
1980                 }
1981
1982                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1983                         // Don't block the user from editing their own talk page unless they've been
1984                         // explicitly blocked from that too.
1985                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1986                         $block = $user->getBlock();
1987
1988                         // This is from OutputPage::blockedPage
1989                         // Copied at r23888 by werdna
1990
1991                         $id = $user->blockedBy();
1992                         $reason = $user->blockedFor();
1993                         if ( $reason == '' ) {
1994                                 $reason = wfMsg( 'blockednoreason' );
1995                         }
1996                         $ip = $user->getRequest()->getIP();
1997
1998                         if ( is_numeric( $id ) ) {
1999                                 $name = User::whoIs( $id );
2000                         } else {
2001                                 $name = $id;
2002                         }
2003
2004                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
2005                         $blockid = $block->getId();
2006                         $blockExpiry = $block->getExpiry();
2007                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
2008                         if ( $blockExpiry == 'infinity' ) {
2009                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
2010                         } else {
2011                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
2012                         }
2013
2014                         $intended = strval( $block->getTarget() );
2015
2016                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
2017                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
2018                 }
2019
2020                 return $errors;
2021         }
2022
2023         /**
2024          * Check that the user is allowed to read this page.
2025          *
2026          * @param $action String the action to check
2027          * @param $user User to check
2028          * @param $errors Array list of current errors
2029          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2030          * @param $short Boolean short circuit on first error
2031          *
2032          * @return Array list of errors
2033          */
2034         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2035                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
2036                 static $useShortcut = null;
2037
2038                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2039                 if ( is_null( $useShortcut ) ) {
2040                         $useShortcut = true;
2041                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
2042                                 # Not a public wiki, so no shortcut
2043                                 $useShortcut = false;
2044                         } elseif ( !empty( $wgRevokePermissions ) ) {
2045                                 /**
2046                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2047                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2048                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2049                                  * reading is allowed.
2050                                  */
2051                                 foreach ( $wgRevokePermissions as $perms ) {
2052                                         if ( !empty( $perms['read'] ) ) {
2053                                                 # We might be removing the read right from the user, so no shortcut
2054                                                 $useShortcut = false;
2055                                                 break;
2056                                         }
2057                                 }
2058                         }
2059                 }
2060
2061                 $whitelisted = false;
2062                 if ( $useShortcut ) {
2063                         # Shortcut for public wikis, allows skipping quite a bit of code
2064                         $whitelisted = true;
2065                 } elseif ( $user->isAllowed( 'read' ) ) {
2066                         # If the user is allowed to read pages, he is allowed to read all pages
2067                         $whitelisted = true;
2068                 } elseif ( $this->isSpecial( 'Userlogin' )
2069                         || $this->isSpecial( 'ChangePassword' )
2070                         || $this->isSpecial( 'PasswordReset' )
2071                 ) {
2072                         # Always grant access to the login page.
2073                         # Even anons need to be able to log in.
2074                         $whitelisted = true;
2075                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2076                         # Time to check the whitelist
2077                         # Only do these checks is there's something to check against
2078                         $name = $this->getPrefixedText();
2079                         $dbName = $this->getPrefixedDBKey();
2080
2081                         // Check for explicit whitelisting with and without underscores
2082                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2083                                 $whitelisted = true;
2084                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2085                                 # Old settings might have the title prefixed with
2086                                 # a colon for main-namespace pages
2087                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2088                                         $whitelisted = true;
2089                                 }
2090                         } elseif ( $this->isSpecialPage() ) {
2091                                 # If it's a special page, ditch the subpage bit and check again
2092                                 $name = $this->getDBkey();
2093                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2094                                 if ( $name !== false ) {
2095                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2096                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2097                                                 $whitelisted = true;
2098                                         }
2099                                 }
2100                         }
2101                 }
2102
2103                 if ( !$whitelisted ) {
2104                         # If the title is not whitelisted, give extensions a chance to do so...
2105                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2106                         if ( !$whitelisted ) {
2107                                 $errors[] = $this->missingPermissionError( $action, $short );
2108                         }
2109                 }
2110
2111                 return $errors;
2112         }
2113
2114         /**
2115          * Get a description array when the user doesn't have the right to perform
2116          * $action (i.e. when User::isAllowed() returns false)
2117          *
2118          * @param $action String the action to check
2119          * @param $short Boolean short circuit on first error
2120          * @return Array list of errors
2121          */
2122         private function missingPermissionError( $action, $short ) {
2123                 // We avoid expensive display logic for quickUserCan's and such
2124                 if ( $short ) {
2125                         return array( 'badaccess-group0' );
2126                 }
2127
2128                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2129                         User::getGroupsWithPermission( $action ) );
2130
2131                 if ( count( $groups ) ) {
2132                         global $wgLang;
2133                         return array(
2134                                 'badaccess-groups',
2135                                 $wgLang->commaList( $groups ),
2136                                 count( $groups )
2137                         );
2138                 } else {
2139                         return array( 'badaccess-group0' );
2140                 }
2141         }
2142
2143         /**
2144          * Can $user perform $action on this page? This is an internal function,
2145          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2146          * checks on wfReadOnly() and blocks)
2147          *
2148          * @param $action String action that permission needs to be checked for
2149          * @param $user User to check
2150          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2151          * @param $short Bool Set this to true to stop after the first permission error.
2152          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2153          */
2154         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2155                 wfProfileIn( __METHOD__ );
2156
2157                 # Read has special handling
2158                 if ( $action == 'read' ) {
2159                         $checks = array(
2160                                 'checkPermissionHooks',
2161                                 'checkReadPermissions',
2162                         );
2163                 } else {
2164                         $checks = array(
2165                                 'checkQuickPermissions',
2166                                 'checkPermissionHooks',
2167                                 'checkSpecialsAndNSPermissions',
2168                                 'checkCSSandJSPermissions',
2169                                 'checkPageRestrictions',
2170                                 'checkCascadingSourcesRestrictions',
2171                                 'checkActionPermissions',
2172                                 'checkUserBlock'
2173                         );
2174                 }
2175
2176                 $errors = array();
2177                 while( count( $checks ) > 0 &&
2178                                 !( $short && count( $errors ) > 0 ) ) {
2179                         $method = array_shift( $checks );
2180                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2181                 }
2182
2183                 wfProfileOut( __METHOD__ );
2184                 return $errors;
2185         }
2186
2187         /**
2188          * Protect css subpages of user pages: can $wgUser edit
2189          * this page?
2190          *
2191          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2192          * @return Bool
2193          */
2194         public function userCanEditCssSubpage() {
2195                 global $wgUser;
2196                 wfDeprecated( __METHOD__, '1.19' );
2197                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2198                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2199         }
2200
2201         /**
2202          * Protect js subpages of user pages: can $wgUser edit
2203          * this page?
2204          *
2205          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2206          * @return Bool
2207          */
2208         public function userCanEditJsSubpage() {
2209                 global $wgUser;
2210                 wfDeprecated( __METHOD__, '1.19' );
2211                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2212                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2213         }
2214
2215         /**
2216          * Get a filtered list of all restriction types supported by this wiki.
2217          * @param bool $exists True to get all restriction types that apply to
2218          * titles that do exist, False for all restriction types that apply to
2219          * titles that do not exist
2220          * @return array
2221          */
2222         public static function getFilteredRestrictionTypes( $exists = true ) {
2223                 global $wgRestrictionTypes;
2224                 $types = $wgRestrictionTypes;
2225                 if ( $exists ) {
2226                         # Remove the create restriction for existing titles
2227                         $types = array_diff( $types, array( 'create' ) );
2228                 } else {
2229                         # Only the create and upload restrictions apply to non-existing titles
2230                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2231                 }
2232                 return $types;
2233         }
2234
2235         /**
2236          * Returns restriction types for the current Title
2237          *
2238          * @return array applicable restriction types
2239          */
2240         public function getRestrictionTypes() {
2241                 if ( $this->isSpecialPage() ) {
2242                         return array();
2243                 }
2244
2245                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2246
2247                 if ( $this->getNamespace() != NS_FILE ) {
2248                         # Remove the upload restriction for non-file titles
2249                         $types = array_diff( $types, array( 'upload' ) );
2250                 }
2251
2252                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2253
2254                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2255                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2256
2257                 return $types;
2258         }
2259
2260         /**
2261          * Is this title subject to title protection?
2262          * Title protection is the one applied against creation of such title.
2263          *
2264          * @return Mixed An associative array representing any existent title
2265          *   protection, or false if there's none.
2266          */
2267         private function getTitleProtection() {
2268                 // Can't protect pages in special namespaces
2269                 if ( $this->getNamespace() < 0 ) {
2270                         return false;
2271                 }
2272
2273                 // Can't protect pages that exist.
2274                 if ( $this->exists() ) {
2275                         return false;
2276                 }
2277
2278                 if ( !isset( $this->mTitleProtection ) ) {
2279                         $dbr = wfGetDB( DB_SLAVE );
2280                         $res = $dbr->select( 'protected_titles', '*',
2281                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2282                                 __METHOD__ );
2283
2284                         // fetchRow returns false if there are no rows.
2285                         $this->mTitleProtection = $dbr->fetchRow( $res );
2286                 }
2287                 return $this->mTitleProtection;
2288         }
2289
2290         /**
2291          * Update the title protection status
2292          *
2293          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2294          * @param $create_perm String Permission required for creation
2295          * @param $reason String Reason for protection
2296          * @param $expiry String Expiry timestamp
2297          * @return boolean true
2298          */
2299         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2300                 wfDeprecated( __METHOD__, '1.19' );
2301
2302                 global $wgUser;
2303
2304                 $limit = array( 'create' => $create_perm );
2305                 $expiry = array( 'create' => $expiry );
2306
2307                 $page = WikiPage::factory( $this );
2308                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2309
2310                 return $status->isOK();
2311         }
2312
2313         /**
2314          * Remove any title protection due to page existing
2315          */
2316         public function deleteTitleProtection() {
2317                 $dbw = wfGetDB( DB_MASTER );
2318
2319                 $dbw->delete(
2320                         'protected_titles',
2321                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2322                         __METHOD__
2323                 );
2324                 $this->mTitleProtection = false;
2325         }
2326
2327         /**
2328          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2329          *
2330          * @param $action String Action to check (default: edit)
2331          * @return Bool
2332          */
2333         public function isSemiProtected( $action = 'edit' ) {
2334                 if ( $this->exists() ) {
2335                         $restrictions = $this->getRestrictions( $action );
2336                         if ( count( $restrictions ) > 0 ) {
2337                                 foreach ( $restrictions as $restriction ) {
2338                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2339                                                 return false;
2340                                         }
2341                                 }
2342                         } else {
2343                                 # Not protected
2344                                 return false;
2345                         }
2346                         return true;
2347                 } else {
2348                         # If it doesn't exist, it can't be protected
2349                         return false;
2350                 }
2351         }
2352
2353         /**
2354          * Does the title correspond to a protected article?
2355          *
2356          * @param $action String the action the page is protected from,
2357          * by default checks all actions.
2358          * @return Bool
2359          */
2360         public function isProtected( $action = '' ) {
2361                 global $wgRestrictionLevels;
2362
2363                 $restrictionTypes = $this->getRestrictionTypes();
2364
2365                 # Special pages have inherent protection
2366                 if( $this->isSpecialPage() ) {
2367                         return true;
2368                 }
2369
2370                 # Check regular protection levels
2371                 foreach ( $restrictionTypes as $type ) {
2372                         if ( $action == $type || $action == '' ) {
2373                                 $r = $this->getRestrictions( $type );
2374                                 foreach ( $wgRestrictionLevels as $level ) {
2375                                         if ( in_array( $level, $r ) && $level != '' ) {
2376                                                 return true;
2377                                         }
2378                                 }
2379                         }
2380                 }
2381
2382                 return false;
2383         }
2384
2385         /**
2386          * Determines if $user is unable to edit this page because it has been protected
2387          * by $wgNamespaceProtection.
2388          *
2389          * @param $user User object to check permissions
2390          * @return Bool
2391          */
2392         public function isNamespaceProtected( User $user ) {
2393                 global $wgNamespaceProtection;
2394
2395                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2396                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2397                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2398                                         return true;
2399                                 }
2400                         }
2401                 }
2402                 return false;
2403         }
2404
2405         /**
2406          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2407          *
2408          * @return Bool If the page is subject to cascading restrictions.
2409          */
2410         public function isCascadeProtected() {
2411                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2412                 return ( $sources > 0 );
2413         }
2414
2415         /**
2416          * Cascading protection: Get the source of any cascading restrictions on this page.
2417          *
2418          * @param $getPages Bool Whether or not to retrieve the actual pages
2419          *        that the restrictions have come from.
2420          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2421          *     have come, false for none, or true if such restrictions exist, but $getPages
2422          *     was not set.  The restriction array is an array of each type, each of which
2423          *     contains a array of unique groups.
2424          */
2425         public function getCascadeProtectionSources( $getPages = true ) {
2426                 global $wgContLang;
2427                 $pagerestrictions = array();
2428
2429                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2430                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2431                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2432                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2433                 }
2434
2435                 wfProfileIn( __METHOD__ );
2436
2437                 $dbr = wfGetDB( DB_SLAVE );
2438
2439                 if ( $this->getNamespace() == NS_FILE ) {
2440                         $tables = array( 'imagelinks', 'page_restrictions' );
2441                         $where_clauses = array(
2442                                 'il_to' => $this->getDBkey(),
2443                                 'il_from=pr_page',
2444                                 'pr_cascade' => 1
2445                         );
2446                 } else {
2447                         $tables = array( 'templatelinks', 'page_restrictions' );
2448                         $where_clauses = array(
2449                                 'tl_namespace' => $this->getNamespace(),
2450                                 'tl_title' => $this->getDBkey(),
2451                                 'tl_from=pr_page',
2452                                 'pr_cascade' => 1
2453                         );
2454                 }
2455
2456                 if ( $getPages ) {
2457                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2458                                                    'pr_expiry', 'pr_type', 'pr_level' );
2459                         $where_clauses[] = 'page_id=pr_page';
2460                         $tables[] = 'page';
2461                 } else {
2462                         $cols = array( 'pr_expiry' );
2463                 }
2464
2465                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2466
2467                 $sources = $getPages ? array() : false;
2468                 $now = wfTimestampNow();
2469                 $purgeExpired = false;
2470
2471                 foreach ( $res as $row ) {
2472                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2473                         if ( $expiry > $now ) {
2474                                 if ( $getPages ) {
2475                                         $page_id = $row->pr_page;
2476                                         $page_ns = $row->page_namespace;
2477                                         $page_title = $row->page_title;
2478                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2479                                         # Add groups needed for each restriction type if its not already there
2480                                         # Make sure this restriction type still exists
2481
2482                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2483                                                 $pagerestrictions[$row->pr_type] = array();
2484                                         }
2485
2486                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2487                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2488                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2489                                         }
2490                                 } else {
2491                                         $sources = true;
2492                                 }
2493                         } else {
2494                                 // Trigger lazy purge of expired restrictions from the db
2495                                 $purgeExpired = true;
2496                         }
2497                 }
2498                 if ( $purgeExpired ) {
2499                         Title::purgeExpiredRestrictions();
2500                 }
2501
2502                 if ( $getPages ) {
2503                         $this->mCascadeSources = $sources;
2504                         $this->mCascadingRestrictions = $pagerestrictions;
2505                 } else {
2506                         $this->mHasCascadingRestrictions = $sources;
2507                 }
2508
2509                 wfProfileOut( __METHOD__ );
2510                 return array( $sources, $pagerestrictions );
2511         }
2512
2513         /**
2514          * Accessor/initialisation for mRestrictions
2515          *
2516          * @param $action String action that permission needs to be checked for
2517          * @return Array of Strings the array of groups allowed to edit this article
2518          */
2519         public function getRestrictions( $action ) {
2520                 if ( !$this->mRestrictionsLoaded ) {
2521                         $this->loadRestrictions();
2522                 }
2523                 return isset( $this->mRestrictions[$action] )
2524                                 ? $this->mRestrictions[$action]
2525                                 : array();
2526         }
2527
2528         /**
2529          * Get the expiry time for the restriction against a given action
2530          *
2531          * @param $action
2532          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2533          *     or not protected at all, or false if the action is not recognised.
2534          */
2535         public function getRestrictionExpiry( $action ) {
2536                 if ( !$this->mRestrictionsLoaded ) {
2537                         $this->loadRestrictions();
2538                 }
2539                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2540         }
2541
2542         /**
2543          * Returns cascading restrictions for the current article
2544          *
2545          * @return Boolean
2546          */
2547         function areRestrictionsCascading() {
2548                 if ( !$this->mRestrictionsLoaded ) {
2549                         $this->loadRestrictions();
2550                 }
2551
2552                 return $this->mCascadeRestriction;
2553         }
2554
2555         /**
2556          * Loads a string into mRestrictions array
2557          *
2558          * @param $res Resource restrictions as an SQL result.
2559          * @param $oldFashionedRestrictions String comma-separated list of page
2560          *        restrictions from page table (pre 1.10)
2561          */
2562         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2563                 $rows = array();
2564
2565                 foreach ( $res as $row ) {
2566                         $rows[] = $row;
2567                 }
2568
2569                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2570         }
2571
2572         /**
2573          * Compiles list of active page restrictions from both page table (pre 1.10)
2574          * and page_restrictions table for this existing page.
2575          * Public for usage by LiquidThreads.
2576          *
2577          * @param $rows array of db result objects
2578          * @param $oldFashionedRestrictions string comma-separated list of page
2579          *        restrictions from page table (pre 1.10)
2580          */
2581         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2582                 global $wgContLang;
2583                 $dbr = wfGetDB( DB_SLAVE );
2584
2585                 $restrictionTypes = $this->getRestrictionTypes();
2586
2587                 foreach ( $restrictionTypes as $type ) {
2588                         $this->mRestrictions[$type] = array();
2589                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2590                 }
2591
2592                 $this->mCascadeRestriction = false;
2593
2594                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2595
2596                 if ( $oldFashionedRestrictions === null ) {
2597                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2598                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2599                 }
2600
2601                 if ( $oldFashionedRestrictions != '' ) {
2602
2603                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2604                                 $temp = explode( '=', trim( $restrict ) );
2605                                 if ( count( $temp ) == 1 ) {
2606                                         // old old format should be treated as edit/move restriction
2607                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2608                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2609                                 } else {
2610                                         $restriction = trim( $temp[1] );
2611                                         if( $restriction != '' ) { //some old entries are empty
2612                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2613                                         }
2614                                 }
2615                         }
2616
2617                         $this->mOldRestrictions = true;
2618
2619                 }
2620
2621                 if ( count( $rows ) ) {
2622                         # Current system - load second to make them override.
2623                         $now = wfTimestampNow();
2624                         $purgeExpired = false;
2625
2626                         # Cycle through all the restrictions.
2627                         foreach ( $rows as $row ) {
2628
2629                                 // Don't take care of restrictions types that aren't allowed
2630                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2631                                         continue;
2632
2633                                 // This code should be refactored, now that it's being used more generally,
2634                                 // But I don't really see any harm in leaving it in Block for now -werdna
2635                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2636
2637                                 // Only apply the restrictions if they haven't expired!
2638                                 if ( !$expiry || $expiry > $now ) {
2639                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2640                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2641
2642                                         $this->mCascadeRestriction |= $row->pr_cascade;
2643                                 } else {
2644                                         // Trigger a lazy purge of expired restrictions
2645                                         $purgeExpired = true;
2646                                 }
2647                         }
2648
2649                         if ( $purgeExpired ) {
2650                                 Title::purgeExpiredRestrictions();
2651                         }
2652                 }
2653
2654                 $this->mRestrictionsLoaded = true;
2655         }
2656
2657         /**
2658          * Load restrictions from the page_restrictions table
2659          *
2660          * @param $oldFashionedRestrictions String comma-separated list of page
2661          *        restrictions from page table (pre 1.10)
2662          */
2663         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2664                 global $wgContLang;
2665                 if ( !$this->mRestrictionsLoaded ) {
2666                         if ( $this->exists() ) {
2667                                 $dbr = wfGetDB( DB_SLAVE );
2668
2669                                 $res = $dbr->select(
2670                                         'page_restrictions',
2671                                         '*',
2672                                         array( 'pr_page' => $this->getArticleID() ),
2673                                         __METHOD__
2674                                 );
2675
2676                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2677                         } else {
2678                                 $title_protection = $this->getTitleProtection();
2679
2680                                 if ( $title_protection ) {
2681                                         $now = wfTimestampNow();
2682                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2683
2684                                         if ( !$expiry || $expiry > $now ) {
2685                                                 // Apply the restrictions
2686                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2687                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2688                                         } else { // Get rid of the old restrictions
2689                                                 Title::purgeExpiredRestrictions();
2690                                                 $this->mTitleProtection = false;
2691                                         }
2692                                 } else {
2693                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2694                                 }
2695                                 $this->mRestrictionsLoaded = true;
2696                         }
2697                 }
2698         }
2699
2700         /**
2701          * Flush the protection cache in this object and force reload from the database.
2702          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2703          */
2704         public function flushRestrictions() {
2705                 $this->mRestrictionsLoaded = false;
2706                 $this->mTitleProtection = null;
2707         }
2708
2709         /**
2710          * Purge expired restrictions from the page_restrictions table
2711          */
2712         static function purgeExpiredRestrictions() {
2713                 $dbw = wfGetDB( DB_MASTER );
2714                 $dbw->delete(
2715                         'page_restrictions',
2716                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2717                         __METHOD__
2718                 );
2719
2720                 $dbw->delete(
2721                         'protected_titles',
2722                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2723                         __METHOD__
2724                 );
2725         }
2726
2727         /**
2728          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2729          *
2730          * @return Bool
2731          */
2732         public function hasSubpages() {
2733                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2734                         # Duh
2735                         return false;
2736                 }
2737
2738                 # We dynamically add a member variable for the purpose of this method
2739                 # alone to cache the result.  There's no point in having it hanging
2740                 # around uninitialized in every Title object; therefore we only add it
2741                 # if needed and don't declare it statically.
2742                 if ( isset( $this->mHasSubpages ) ) {
2743                         return $this->mHasSubpages;
2744                 }
2745
2746                 $subpages = $this->getSubpages( 1 );
2747                 if ( $subpages instanceof TitleArray ) {
2748                         return $this->mHasSubpages = (bool)$subpages->count();
2749                 }
2750                 return $this->mHasSubpages = false;
2751         }
2752
2753         /**
2754          * Get all subpages of this page.
2755          *
2756          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2757          * @return mixed TitleArray, or empty array if this page's namespace
2758          *  doesn't allow subpages
2759          */
2760         public function getSubpages( $limit = -1 ) {
2761                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2762                         return array();
2763                 }
2764
2765                 $dbr = wfGetDB( DB_SLAVE );
2766                 $conds['page_namespace'] = $this->getNamespace();
2767                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2768                 $options = array();
2769                 if ( $limit > -1 ) {
2770                         $options['LIMIT'] = $limit;
2771                 }
2772                 return $this->mSubpages = TitleArray::newFromResult(
2773                         $dbr->select( 'page',
2774                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2775                                 $conds,
2776                                 __METHOD__,
2777                                 $options
2778                         )
2779                 );
2780         }
2781
2782         /**
2783          * Is there a version of this page in the deletion archive?
2784          *
2785          * @return Int the number of archived revisions
2786          */
2787         public function isDeleted() {
2788                 if ( $this->getNamespace() < 0 ) {
2789                         $n = 0;
2790                 } else {
2791                         $dbr = wfGetDB( DB_SLAVE );
2792
2793                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2794                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2795                                 __METHOD__
2796                         );
2797                         if ( $this->getNamespace() == NS_FILE ) {
2798                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2799                                         array( 'fa_name' => $this->getDBkey() ),
2800                                         __METHOD__
2801                                 );
2802                         }
2803                 }
2804                 return (int)$n;
2805         }
2806
2807         /**
2808          * Is there a version of this page in the deletion archive?
2809          *
2810          * @return Boolean
2811          */
2812         public function isDeletedQuick() {
2813                 if ( $this->getNamespace() < 0 ) {
2814                         return false;
2815                 }
2816                 $dbr = wfGetDB( DB_SLAVE );
2817                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2818                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2819                         __METHOD__
2820                 );
2821                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2822                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2823                                 array( 'fa_name' => $this->getDBkey() ),
2824                                 __METHOD__
2825                         );
2826                 }
2827                 return $deleted;
2828         }
2829
2830         /**
2831          * Get the article ID for this Title from the link cache,
2832          * adding it if necessary
2833          *
2834          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2835          *  for update
2836          * @return Int the ID
2837          */
2838         public function getArticleID( $flags = 0 ) {
2839                 if ( $this->getNamespace() < 0 ) {
2840                         return $this->mArticleID = 0;
2841                 }
2842                 $linkCache = LinkCache::singleton();
2843                 if ( $flags & self::GAID_FOR_UPDATE ) {
2844                         $oldUpdate = $linkCache->forUpdate( true );
2845                         $linkCache->clearLink( $this );
2846                         $this->mArticleID = $linkCache->addLinkObj( $this );
2847                         $linkCache->forUpdate( $oldUpdate );
2848                 } else {
2849                         if ( -1 == $this->mArticleID ) {
2850                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2851                         }
2852                 }
2853                 return $this->mArticleID;
2854         }
2855
2856         /**
2857          * Is this an article that is a redirect page?
2858          * Uses link cache, adding it if necessary
2859          *
2860          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2861          * @return Bool
2862          */
2863         public function isRedirect( $flags = 0 ) {
2864                 if ( !is_null( $this->mRedirect ) ) {
2865                         return $this->mRedirect;
2866                 }
2867                 # Calling getArticleID() loads the field from cache as needed
2868                 if ( !$this->getArticleID( $flags ) ) {
2869                         return $this->mRedirect = false;
2870                 }
2871
2872                 $linkCache = LinkCache::singleton();
2873                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2874                 assert( $cached !== null ); # assert the assumption that the cache actually knows about this title #XXX breaks stuff #TODO: use exception
2875
2876                 $this->mRedirect = (bool)$cached;
2877
2878                 return $this->mRedirect;
2879         }
2880
2881         /**
2882          * What is the length of this page?
2883          * Uses link cache, adding it if necessary
2884          *
2885          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2886          * @return Int
2887          */
2888         public function getLength( $flags = 0 ) {
2889                 if ( $this->mLength != -1 ) {
2890                         return $this->mLength;
2891                 }
2892                 # Calling getArticleID() loads the field from cache as needed
2893                 if ( !$this->getArticleID( $flags ) ) {
2894                         return $this->mLength = 0;
2895                 }
2896                 $linkCache = LinkCache::singleton();
2897                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
2898                 assert( $cached !== null ); # assert the assumption that the cache actually knows about this title #TODO: use exception
2899
2900                 $this->mLength = intval( $cached );
2901
2902                 return $this->mLength;
2903         }
2904
2905         /**
2906          * What is the page_latest field for this page?
2907          *
2908          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2909          * @return Int or 0 if the page doesn't exist
2910          */
2911         public function getLatestRevID( $flags = 0 ) {
2912                 if ( $this->mLatestID !== false ) {
2913                         return intval( $this->mLatestID );
2914                 }
2915                 # Calling getArticleID() loads the field from cache as needed
2916                 if ( !$this->getArticleID( $flags ) ) {
2917                         return $this->mLatestID = 0;
2918                 }
2919                 $linkCache = LinkCache::singleton();
2920                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
2921                 assert( $cached !== null ); # assert the assumption that the cache actually knows about this title #TODO: use exception
2922
2923                 $this->mLatestID = intval( $cached );
2924
2925                 return $this->mLatestID;
2926         }
2927
2928         /**
2929          * This clears some fields in this object, and clears any associated
2930          * keys in the "bad links" section of the link cache.
2931          *
2932          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2933          * loading of the new page_id. It's also called from
2934          * WikiPage::doDeleteArticle()
2935          *
2936          * @param $newid Int the new Article ID
2937          */
2938         public function resetArticleID( $newid ) {
2939                 $linkCache = LinkCache::singleton();
2940                 $linkCache->clearLink( $this );
2941
2942                 if ( $newid === false ) {
2943                         $this->mArticleID = -1;
2944                 } else {
2945                         $this->mArticleID = intval( $newid );
2946                 }
2947                 $this->mRestrictionsLoaded = false;
2948                 $this->mRestrictions = array();
2949                 $this->mRedirect = null;
2950                 $this->mLength = -1;
2951                 $this->mLatestID = false;
2952                 $this->mEstimateRevisions = null;
2953         }
2954
2955         /**
2956          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2957          *
2958          * @param $text String containing title to capitalize
2959          * @param $ns int namespace index, defaults to NS_MAIN
2960          * @return String containing capitalized title
2961          */
2962         public static function capitalize( $text, $ns = NS_MAIN ) {
2963                 global $wgContLang;
2964
2965                 if ( MWNamespace::isCapitalized( $ns ) ) {
2966                         return $wgContLang->ucfirst( $text );
2967                 } else {
2968                         return $text;
2969                 }
2970         }
2971
2972         /**
2973          * Secure and split - main initialisation function for this object
2974          *
2975          * Assumes that mDbkeyform has been set, and is urldecoded
2976          * and uses underscores, but not otherwise munged.  This function
2977          * removes illegal characters, splits off the interwiki and
2978          * namespace prefixes, sets the other forms, and canonicalizes
2979          * everything.
2980          *
2981          * @return Bool true on success
2982          */
2983         private function secureAndSplit() {
2984                 global $wgContLang, $wgLocalInterwiki;
2985
2986                 # Initialisation
2987                 $this->mInterwiki = $this->mFragment = '';
2988                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2989
2990                 $dbkey = $this->mDbkeyform;
2991
2992                 # Strip Unicode bidi override characters.
2993                 # Sometimes they slip into cut-n-pasted page titles, where the
2994                 # override chars get included in list displays.
2995                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2996
2997                 # Clean up whitespace
2998                 # Note: use of the /u option on preg_replace here will cause
2999                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
3000                 # conveniently disabling them.
3001                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
3002                 $dbkey = trim( $dbkey, '_' );
3003
3004                 if ( $dbkey == '' ) {
3005                         return false;
3006                 }
3007
3008                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
3009                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
3010                         return false;
3011                 }
3012
3013                 $this->mDbkeyform = $dbkey;
3014
3015                 # Initial colon indicates main namespace rather than specified default
3016                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
3017                 if ( ':' == $dbkey[0] ) {
3018                         $this->mNamespace = NS_MAIN;
3019                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
3020                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3021                 }
3022
3023                 # Namespace or interwiki prefix
3024                 $firstPass = true;
3025                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3026                 do {
3027                         $m = array();
3028                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3029                                 $p = $m[1];
3030                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3031                                         # Ordinary namespace
3032                                         $dbkey = $m[2];
3033                                         $this->mNamespace = $ns;
3034                                         # For Talk:X pages, check if X has a "namespace" prefix
3035                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3036                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3037                                                         # Disallow Talk:File:x type titles...
3038                                                         return false;
3039                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3040                                                         # Disallow Talk:Interwiki:x type titles...
3041                                                         return false;
3042                                                 }
3043                                         }
3044                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3045                                         if ( !$firstPass ) {
3046                                                 # Can't make a local interwiki link to an interwiki link.
3047                                                 # That's just crazy!
3048                                                 return false;
3049                                         }
3050
3051                                         # Interwiki link
3052                                         $dbkey = $m[2];
3053                                         $this->mInterwiki = $wgContLang->lc( $p );
3054
3055                                         # Redundant interwiki prefix to the local wiki
3056                                         if ( $wgLocalInterwiki !== false
3057                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3058                                         {
3059                                                 if ( $dbkey == '' ) {
3060                                                         # Can't have an empty self-link
3061                                                         return false;
3062                                                 }
3063                                                 $this->mInterwiki = '';
3064                                                 $firstPass = false;
3065                                                 # Do another namespace split...
3066                                                 continue;
3067                                         }
3068
3069                                         # If there's an initial colon after the interwiki, that also
3070                                         # resets the default namespace
3071                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3072                                                 $this->mNamespace = NS_MAIN;
3073                                                 $dbkey = substr( $dbkey, 1 );
3074                                         }
3075                                 }
3076                                 # If there's no recognized interwiki or namespace,
3077                                 # then let the colon expression be part of the title.
3078                         }
3079                         break;
3080                 } while ( true );
3081
3082                 # We already know that some pages won't be in the database!
3083                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3084                         $this->mArticleID = 0;
3085                 }
3086                 $fragment = strstr( $dbkey, '#' );
3087                 if ( false !== $fragment ) {
3088                         $this->setFragment( $fragment );
3089                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3090                         # remove whitespace again: prevents "Foo_bar_#"
3091                         # becoming "Foo_bar_"
3092                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3093                 }
3094
3095                 # Reject illegal characters.
3096                 $rxTc = self::getTitleInvalidRegex();
3097                 if ( preg_match( $rxTc, $dbkey ) ) {
3098                         return false;
3099                 }
3100
3101                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3102                 # reachable due to the way web browsers deal with 'relative' URLs.
3103                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3104                 if ( strpos( $dbkey, '.' ) !== false &&
3105                          ( $dbkey === '.' || $dbkey === '..' ||
3106                            strpos( $dbkey, './' ) === 0  ||
3107                            strpos( $dbkey, '../' ) === 0 ||
3108                            strpos( $dbkey, '/./' ) !== false ||
3109                            strpos( $dbkey, '/../' ) !== false  ||
3110                            substr( $dbkey, -2 ) == '/.' ||
3111                            substr( $dbkey, -3 ) == '/..' ) )
3112                 {
3113                         return false;
3114                 }
3115
3116                 # Magic tilde sequences? Nu-uh!
3117                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3118                         return false;
3119                 }
3120
3121                 # Limit the size of titles to 255 bytes. This is typically the size of the
3122                 # underlying database field. We make an exception for special pages, which
3123                 # don't need to be stored in the database, and may edge over 255 bytes due
3124                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3125                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3126                   strlen( $dbkey ) > 512 )
3127                 {
3128                         return false;
3129                 }
3130
3131                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3132                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3133                 # other site might be case-sensitive.
3134                 $this->mUserCaseDBKey = $dbkey;
3135                 if ( $this->mInterwiki == '' ) {
3136                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3137                 }
3138
3139                 # Can't make a link to a namespace alone... "empty" local links can only be
3140                 # self-links with a fragment identifier.
3141                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3142                         return false;
3143                 }
3144
3145                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3146                 // IP names are not allowed for accounts, and can only be referring to
3147                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3148                 // there are numerous ways to present the same IP. Having sp:contribs scan
3149                 // them all is silly and having some show the edits and others not is
3150                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3151                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3152                         ? IP::sanitizeIP( $dbkey )
3153                         : $dbkey;
3154
3155                 // Any remaining initial :s are illegal.
3156                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3157                         return false;
3158                 }
3159
3160                 # Fill fields
3161                 $this->mDbkeyform = $dbkey;
3162                 $this->mUrlform = wfUrlencode( $dbkey );
3163
3164                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3165
3166                 return true;
3167         }
3168
3169         /**
3170          * Get an array of Title objects linking to this Title
3171          * Also stores the IDs in the link cache.
3172          *
3173          * WARNING: do not use this function on arbitrary user-supplied titles!
3174          * On heavily-used templates it will max out the memory.
3175          *
3176          * @param $options Array: may be FOR UPDATE
3177          * @param $table String: table name
3178          * @param $prefix String: fields prefix
3179          * @return Array of Title objects linking here
3180          */
3181         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3182                 if ( count( $options ) > 0 ) {
3183                         $db = wfGetDB( DB_MASTER );
3184                 } else {
3185                         $db = wfGetDB( DB_SLAVE );
3186                 }
3187
3188                 $res = $db->select(
3189                         array( 'page', $table ),
3190                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3191                         array(
3192                                 "{$prefix}_from=page_id",
3193                                 "{$prefix}_namespace" => $this->getNamespace(),
3194                                 "{$prefix}_title"     => $this->getDBkey() ),
3195                         __METHOD__,
3196                         $options
3197                 );
3198
3199                 $retVal = array();
3200                 if ( $res->numRows() ) {
3201                         $linkCache = LinkCache::singleton();
3202                         foreach ( $res as $row ) {
3203                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3204                                 if ( $titleObj ) {
3205                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3206                                         $retVal[] = $titleObj;
3207                                 }
3208                         }
3209                 }
3210                 return $retVal;
3211         }
3212
3213         /**
3214          * Get an array of Title objects using this Title as a template
3215          * Also stores the IDs in the link cache.
3216          *
3217          * WARNING: do not use this function on arbitrary user-supplied titles!
3218          * On heavily-used templates it will max out the memory.
3219          *
3220          * @param $options Array: may be FOR UPDATE
3221          * @return Array of Title the Title objects linking here
3222          */
3223         public function getTemplateLinksTo( $options = array() ) {
3224                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3225         }
3226
3227         /**
3228          * Get an array of Title objects linked from this Title
3229          * Also stores the IDs in the link cache.
3230          *
3231          * WARNING: do not use this function on arbitrary user-supplied titles!
3232          * On heavily-used templates it will max out the memory.
3233          *
3234          * @param $options Array: may be FOR UPDATE
3235          * @param $table String: table name
3236          * @param $prefix String: fields prefix
3237          * @return Array of Title objects linking here
3238          */
3239         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3240                 $id = $this->getArticleID();
3241
3242                 # If the page doesn't exist; there can't be any link from this page
3243                 if ( !$id ) {
3244                         return array();
3245                 }
3246
3247                 if ( count( $options ) > 0 ) {
3248                         $db = wfGetDB( DB_MASTER );
3249                 } else {
3250                         $db = wfGetDB( DB_SLAVE );
3251                 }
3252
3253                 $namespaceFiled = "{$prefix}_namespace";
3254                 $titleField = "{$prefix}_title";
3255
3256                 $res = $db->select(
3257                         array( $table, 'page' ),
3258                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3259                         array( "{$prefix}_from" => $id ),
3260                         __METHOD__,
3261                         $options,
3262                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3263                 );
3264
3265                 $retVal = array();
3266                 if ( $res->numRows() ) {
3267                         $linkCache = LinkCache::singleton();
3268                         foreach ( $res as $row ) {
3269                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3270                                 if ( $titleObj ) {
3271                                         if ( $row->page_id ) {
3272                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3273                                         } else {
3274                                                 $linkCache->addBadLinkObj( $titleObj );
3275                                         }
3276                                         $retVal[] = $titleObj;
3277                                 }
3278                         }
3279                 }
3280                 return $retVal;
3281         }
3282
3283         /**
3284          * Get an array of Title objects used on this Title as a template
3285          * Also stores the IDs in the link cache.
3286          *
3287          * WARNING: do not use this function on arbitrary user-supplied titles!
3288          * On heavily-used templates it will max out the memory.
3289          *
3290          * @param $options Array: may be FOR UPDATE
3291          * @return Array of Title the Title objects used here
3292          */
3293         public function getTemplateLinksFrom( $options = array() ) {
3294                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3295         }
3296
3297         /**
3298          * Get an array of Title objects referring to non-existent articles linked from this page
3299          *
3300          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3301          * @return Array of Title the Title objects
3302          */
3303         public function getBrokenLinksFrom() {
3304                 if ( $this->getArticleID() == 0 ) {
3305                         # All links from article ID 0 are false positives
3306                         return array();
3307                 }
3308
3309                 $dbr = wfGetDB( DB_SLAVE );
3310                 $res = $dbr->select(
3311                         array( 'page', 'pagelinks' ),
3312                         array( 'pl_namespace', 'pl_title' ),
3313                         array(
3314                                 'pl_from' => $this->getArticleID(),
3315                                 'page_namespace IS NULL'
3316                         ),
3317                         __METHOD__, array(),
3318                         array(
3319                                 'page' => array(
3320                                         'LEFT JOIN',
3321                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3322                                 )
3323                         )
3324                 );
3325
3326                 $retVal = array();
3327                 foreach ( $res as $row ) {
3328                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3329                 }
3330                 return $retVal;
3331         }
3332
3333
3334         /**
3335          * Get a list of URLs to purge from the Squid cache when this
3336          * page changes
3337          *
3338          * @return Array of String the URLs
3339          */
3340         public function getSquidURLs() {
3341                 global $wgContLang;
3342
3343                 $urls = array(
3344                         $this->getInternalURL(),
3345                         $this->getInternalURL( 'action=history' )
3346                 );
3347
3348                 // purge variant urls as well
3349                 if ( $wgContLang->hasVariants() ) {
3350                         $variants = $wgContLang->getVariants();
3351                         foreach ( $variants as $vCode ) {
3352                                 $urls[] = $this->getInternalURL( '', $vCode );
3353                         }
3354                 }
3355
3356                 return $urls;
3357         }
3358
3359         /**
3360          * Purge all applicable Squid URLs
3361          */
3362         public function purgeSquid() {
3363                 global $wgUseSquid;
3364                 if ( $wgUseSquid ) {
3365                         $urls = $this->getSquidURLs();
3366                         $u = new SquidUpdate( $urls );
3367                         $u->doUpdate();
3368                 }
3369         }
3370
3371         /**
3372          * Move this page without authentication
3373          *
3374          * @param $nt Title the new page Title
3375          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3376          */
3377         public function moveNoAuth( &$nt ) {
3378                 return $this->moveTo( $nt, false );
3379         }
3380
3381         /**
3382          * Check whether a given move operation would be valid.
3383          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3384          *
3385          * @param $nt Title the new title
3386          * @param $auth Bool indicates whether $wgUser's permissions
3387          *  should be checked
3388          * @param $reason String is the log summary of the move, used for spam checking
3389          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3390          */
3391         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3392                 global $wgUser;
3393
3394                 $errors = array();
3395                 if ( !$nt ) {
3396                         // Normally we'd add this to $errors, but we'll get
3397                         // lots of syntax errors if $nt is not an object
3398                         return array( array( 'badtitletext' ) );
3399                 }
3400                 if ( $this->equals( $nt ) ) {
3401                         $errors[] = array( 'selfmove' );
3402                 }
3403                 if ( !$this->isMovable() ) {
3404                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3405                 }
3406                 if ( $nt->getInterwiki() != '' ) {
3407                         $errors[] = array( 'immobile-target-namespace-iw' );
3408                 }
3409                 if ( !$nt->isMovable() ) {
3410                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3411                 }
3412
3413                 $oldid = $this->getArticleID();
3414                 $newid = $nt->getArticleID();
3415
3416                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3417                         $errors[] = array( 'articleexists' );
3418                 }
3419                 if ( ( $this->getDBkey() == '' ) ||
3420                          ( !$oldid ) ||
3421                          ( $nt->getDBkey() == '' ) ) {
3422                         $errors[] = array( 'badarticleerror' );
3423                 }
3424
3425                 // Image-specific checks
3426                 if ( $this->getNamespace() == NS_FILE ) {
3427                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3428                 }
3429
3430                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3431                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3432                 }
3433
3434                 if ( $auth ) {
3435                         $errors = wfMergeErrorArrays( $errors,
3436                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3437                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3438                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3439                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3440                 }
3441
3442                 $match = EditPage::matchSummarySpamRegex( $reason );
3443                 if ( $match !== false ) {
3444                         // This is kind of lame, won't display nice
3445                         $errors[] = array( 'spamprotectiontext' );
3446                 }
3447
3448                 $err = null;
3449                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3450                         $errors[] = array( 'hookaborted', $err );
3451                 }
3452
3453                 # The move is allowed only if (1) the target doesn't exist, or
3454                 # (2) the target is a redirect to the source, and has no history
3455                 # (so we can undo bad moves right after they're done).
3456
3457                 if ( 0 != $newid ) { # Target exists; check for validity
3458                         if ( !$this->isValidMoveTarget( $nt ) ) {
3459                                 $errors[] = array( 'articleexists' );
3460                         }
3461                 } else {
3462                         $tp = $nt->getTitleProtection();
3463                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3464                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3465                                 $errors[] = array( 'cantmove-titleprotected' );
3466                         }
3467                 }
3468                 if ( empty( $errors ) ) {
3469                         return true;
3470                 }
3471                 return $errors;
3472         }
3473
3474         /**
3475          * Check if the requested move target is a valid file move target
3476          * @param Title $nt Target title
3477          * @return array List of errors
3478          */
3479         protected function validateFileMoveOperation( $nt ) {
3480                 global $wgUser;
3481
3482                 $errors = array();
3483
3484                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3485
3486                 $file = wfLocalFile( $this );
3487                 if ( $file->exists() ) {
3488                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3489                                 $errors[] = array( 'imageinvalidfilename' );
3490                         }
3491                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3492                                 $errors[] = array( 'imagetypemismatch' );
3493                         }
3494                 }
3495
3496                 if ( $nt->getNamespace() != NS_FILE ) {
3497                         $errors[] = array( 'imagenocrossnamespace' );
3498                         // From here we want to do checks on a file object, so if we can't
3499                         // create one, we must return.
3500                         return $errors;
3501                 }
3502
3503                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3504
3505                 $destFile = wfLocalFile( $nt );
3506                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3507                         $errors[] = array( 'file-exists-sharedrepo' );
3508                 }
3509
3510                 return $errors;
3511         }
3512
3513         /**
3514          * Move a title to a new location
3515          *
3516          * @param $nt Title the new title
3517          * @param $auth Bool indicates whether $wgUser's permissions
3518          *  should be checked
3519          * @param $reason String the reason for the move
3520          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3521          *  Ignored if the user doesn't have the suppressredirect right.
3522          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3523          */
3524         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3525                 global $wgUser;
3526                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3527                 if ( is_array( $err ) ) {
3528                         // Auto-block user's IP if the account was "hard" blocked
3529                         $wgUser->spreadAnyEditBlock();
3530                         return $err;
3531                 }
3532
3533                 // If it is a file, move it first.
3534                 // It is done before all other moving stuff is done because it's hard to revert.
3535                 $dbw = wfGetDB( DB_MASTER );
3536                 if ( $this->getNamespace() == NS_FILE ) {
3537                         $file = wfLocalFile( $this );
3538                         if ( $file->exists() ) {
3539                                 $status = $file->move( $nt );
3540                                 if ( !$status->isOk() ) {
3541                                         return $status->getErrorsArray();
3542                                 }
3543                         }
3544                         // Clear RepoGroup process cache
3545                         RepoGroup::singleton()->clearCache( $this );
3546                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3547                 }
3548
3549                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3550                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3551                 $protected = $this->isProtected();
3552
3553                 // Do the actual move
3554                 $this->moveToInternal( $nt, $reason, $createRedirect );
3555
3556                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3557                 // cl_timestamp, which may disturb time-based lists on some sites.
3558                 $prefixes = $dbw->select(
3559                         'categorylinks',
3560                         array( 'cl_sortkey_prefix', 'cl_to' ),
3561                         array( 'cl_from' => $pageid ),
3562                         __METHOD__
3563                 );
3564                 foreach ( $prefixes as $prefixRow ) {
3565                         $prefix = $prefixRow->cl_sortkey_prefix;
3566                         $catTo = $prefixRow->cl_to;
3567                         $dbw->update( 'categorylinks',
3568                                 array(
3569                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3570                                                 $nt->getCategorySortkey( $prefix ) ),
3571                                         'cl_timestamp=cl_timestamp' ),
3572                                 array(
3573                                         'cl_from' => $pageid,
3574                                         'cl_to' => $catTo ),
3575                                 __METHOD__
3576                         );
3577                 }
3578
3579                 $redirid = $this->getArticleID();
3580
3581                 if ( $protected ) {
3582                         # Protect the redirect title as the title used to be...
3583                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3584                                 array(
3585                                         'pr_page'    => $redirid,
3586                                         'pr_type'    => 'pr_type',
3587                                         'pr_level'   => 'pr_level',
3588                                         'pr_cascade' => 'pr_cascade',
3589                                         'pr_user'    => 'pr_user',
3590                                         'pr_expiry'  => 'pr_expiry'
3591                                 ),
3592                                 array( 'pr_page' => $pageid ),
3593                                 __METHOD__,
3594                                 array( 'IGNORE' )
3595                         );
3596                         # Update the protection log
3597                         $log = new LogPage( 'protect' );
3598                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3599                         if ( $reason ) {
3600                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3601                         }
3602                         // @todo FIXME: $params?
3603                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3604                 }
3605
3606                 # Update watchlists
3607                 $oldnamespace = $this->getNamespace() & ~1;
3608                 $newnamespace = $nt->getNamespace() & ~1;
3609                 $oldtitle = $this->getDBkey();
3610                 $newtitle = $nt->getDBkey();
3611
3612                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3613                         WatchedItem::duplicateEntries( $this, $nt );
3614                 }
3615
3616                 $dbw->commit( __METHOD__ );
3617
3618                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3619                 return true;
3620         }
3621
3622         /**
3623          * Move page to a title which is either a redirect to the
3624          * source page or nonexistent
3625          *
3626          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3627          * @param $reason String The reason for the move
3628          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3629          *   if the user doesn't have the suppressredirect right
3630          * @throws MWException
3631          */
3632         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3633                 global $wgUser, $wgContLang;
3634
3635                 if ( $nt->exists() ) {
3636                         $moveOverRedirect = true;
3637                         $logType = 'move_redir';
3638                 } else {
3639                         $moveOverRedirect = false;
3640                         $logType = 'move';
3641                 }
3642
3643                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3644
3645                 $logEntry = new ManualLogEntry( 'move', $logType );
3646                 $logEntry->setPerformer( $wgUser );
3647                 $logEntry->setTarget( $this );
3648                 $logEntry->setComment( $reason );
3649                 $logEntry->setParameters( array(
3650                         '4::target' => $nt->getPrefixedText(),
3651                         '5::noredir' => $redirectSuppressed ? '1': '0',
3652                 ) );
3653
3654                 $formatter = LogFormatter::newFromEntry( $logEntry );
3655                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3656                 $comment = $formatter->getPlainActionText();
3657                 if ( $reason ) {
3658                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3659                 }
3660                 # Truncate for whole multibyte characters.
3661                 $comment = $wgContLang->truncate( $comment, 255 );
3662
3663                 $oldid = $this->getArticleID();
3664
3665                 $dbw = wfGetDB( DB_MASTER );
3666
3667                 $newpage = WikiPage::factory( $nt );
3668
3669                 if ( $moveOverRedirect ) {
3670                         $newid = $nt->getArticleID();
3671
3672                         # Delete the old redirect. We don't save it to history since
3673                         # by definition if we've got here it's rather uninteresting.
3674                         # We have to remove it so that the next step doesn't trigger
3675                         # a conflict on the unique namespace+title index...
3676                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3677
3678                         $newpage->doDeleteUpdates( $newid );
3679                 }
3680
3681                 # Save a null revision in the page's history notifying of the move
3682                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3683                 if ( !is_object( $nullRevision ) ) {
3684                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3685                 }
3686                 $nullRevId = $nullRevision->insertOn( $dbw );
3687
3688                 # Change the name of the target page:
3689                 $dbw->update( 'page',
3690                         /* SET */ array(
3691                                 'page_namespace' => $nt->getNamespace(),
3692                                 'page_title'     => $nt->getDBkey(),
3693                         ),
3694                         /* WHERE */ array( 'page_id' => $oldid ),
3695                         __METHOD__
3696                 );
3697
3698                 $this->resetArticleID( 0 );
3699                 $nt->resetArticleID( $oldid );
3700
3701                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3702
3703                 wfRunHooks( 'NewRevisionFromEditComplete',
3704                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3705
3706                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3707
3708                 if ( !$moveOverRedirect ) {
3709                         WikiPage::onArticleCreate( $nt );
3710                 }
3711
3712                 # Recreate the redirect, this time in the other direction.
3713                 if ( $redirectSuppressed ) {
3714                         WikiPage::onArticleDelete( $this );
3715                 } else {
3716                         $mwRedir = MagicWord::get( 'redirect' );
3717                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3718                         $redirectArticle = WikiPage::factory( $this );
3719                         $newid = $redirectArticle->insertOn( $dbw );
3720                         if ( $newid ) { // sanity
3721                                 $redirectRevision = new Revision( array(
3722                                         'page'    => $newid,
3723                                         'comment' => $comment,
3724                                         'text'    => $redirectText ) );
3725                                 $redirectRevision->insertOn( $dbw );
3726                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3727
3728                                 wfRunHooks( 'NewRevisionFromEditComplete',
3729                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3730
3731                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3732                         }
3733                 }
3734
3735                 # Log the move
3736                 $logid = $logEntry->insert();
3737                 $logEntry->publish( $logid );
3738         }
3739
3740         /**
3741          * Move this page's subpages to be subpages of $nt
3742          *
3743          * @param $nt Title Move target
3744          * @param $auth bool Whether $wgUser's permissions should be checked
3745          * @param $reason string The reason for the move
3746          * @param $createRedirect bool Whether to create redirects from the old subpages to
3747          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3748          * @return mixed array with old page titles as keys, and strings (new page titles) or
3749          *     arrays (errors) as values, or an error array with numeric indices if no pages
3750          *     were moved
3751          */
3752         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3753                 global $wgMaximumMovedPages;
3754                 // Check permissions
3755                 if ( !$this->userCan( 'move-subpages' ) ) {
3756                         return array( 'cant-move-subpages' );
3757                 }
3758                 // Do the source and target namespaces support subpages?
3759                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3760                         return array( 'namespace-nosubpages',
3761                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3762                 }
3763                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3764                         return array( 'namespace-nosubpages',
3765                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3766                 }
3767
3768                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3769                 $retval = array();
3770                 $count = 0;
3771                 foreach ( $subpages as $oldSubpage ) {
3772                         $count++;
3773                         if ( $count > $wgMaximumMovedPages ) {
3774                                 $retval[$oldSubpage->getPrefixedTitle()] =
3775                                                 array( 'movepage-max-pages',
3776                                                         $wgMaximumMovedPages );
3777                                 break;
3778                         }
3779
3780                         // We don't know whether this function was called before
3781                         // or after moving the root page, so check both
3782                         // $this and $nt
3783                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3784                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3785                         {
3786                                 // When moving a page to a subpage of itself,
3787                                 // don't move it twice
3788                                 continue;
3789                         }
3790                         $newPageName = preg_replace(
3791                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3792                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3793                                         $oldSubpage->getDBkey() );
3794                         if ( $oldSubpage->isTalkPage() ) {
3795                                 $newNs = $nt->getTalkPage()->getNamespace();
3796                         } else {
3797                                 $newNs = $nt->getSubjectPage()->getNamespace();
3798                         }
3799                         # Bug 14385: we need makeTitleSafe because the new page names may
3800                         # be longer than 255 characters.
3801                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3802
3803                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3804                         if ( $success === true ) {
3805                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3806                         } else {
3807                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3808                         }
3809                 }
3810                 return $retval;
3811         }
3812
3813         /**
3814          * Checks if this page is just a one-rev redirect.
3815          * Adds lock, so don't use just for light purposes.
3816          *
3817          * @return Bool
3818          */
3819         public function isSingleRevRedirect() {
3820                 $dbw = wfGetDB( DB_MASTER );
3821                 # Is it a redirect?
3822                 $row = $dbw->selectRow( 'page',
3823                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3824                         $this->pageCond(),
3825                         __METHOD__,
3826                         array( 'FOR UPDATE' )
3827                 );
3828                 # Cache some fields we may want
3829                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3830                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3831                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3832                 if ( !$this->mRedirect ) {
3833                         return false;
3834                 }
3835                 # Does the article have a history?
3836                 $row = $dbw->selectField( array( 'page', 'revision' ),
3837                         'rev_id',
3838                         array( 'page_namespace' => $this->getNamespace(),
3839                                 'page_title' => $this->getDBkey(),
3840                                 'page_id=rev_page',
3841                                 'page_latest != rev_id'
3842                         ),
3843                         __METHOD__,
3844                         array( 'FOR UPDATE' )
3845                 );
3846                 # Return true if there was no history
3847                 return ( $row === false );
3848         }
3849
3850         /**
3851          * Checks if $this can be moved to a given Title
3852          * - Selects for update, so don't call it unless you mean business
3853          *
3854          * @param $nt Title the new title to check
3855          * @return Bool
3856          */
3857         public function isValidMoveTarget( $nt ) {
3858                 # Is it an existing file?
3859                 if ( $nt->getNamespace() == NS_FILE ) {
3860                         $file = wfLocalFile( $nt );
3861                         if ( $file->exists() ) {
3862                                 wfDebug( __METHOD__ . ": file exists\n" );
3863                                 return false;
3864                         }
3865                 }
3866                 # Is it a redirect with no history?
3867                 if ( !$nt->isSingleRevRedirect() ) {
3868                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3869                         return false;
3870                 }
3871                 # Get the article text
3872                 $rev = Revision::newFromTitle( $nt );
3873                 if( !is_object( $rev ) ){
3874                         return false;
3875                 }
3876                 $text = $rev->getText();
3877                 # Does the redirect point to the source?
3878                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3879                 $m = array();
3880                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3881                         $redirTitle = Title::newFromText( $m[1] );
3882                         if ( !is_object( $redirTitle ) ||
3883                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3884                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3885                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3886                                 return false;
3887                         }
3888                 } else {
3889                         # Fail safe
3890                         wfDebug( __METHOD__ . ": failsafe\n" );
3891                         return false;
3892                 }
3893                 return true;
3894         }
3895
3896         /**
3897          * Get categories to which this Title belongs and return an array of
3898          * categories' names.
3899          *
3900          * @return Array of parents in the form:
3901          *        $parent => $currentarticle
3902          */
3903         public function getParentCategories() {
3904                 global $wgContLang;
3905
3906                 $data = array();
3907
3908                 $titleKey = $this->getArticleID();
3909
3910                 if ( $titleKey === 0 ) {
3911                         return $data;
3912                 }
3913
3914                 $dbr = wfGetDB( DB_SLAVE );
3915
3916                 $res = $dbr->select( 'categorylinks', '*',
3917                         array(
3918                                 'cl_from' => $titleKey,
3919                         ),
3920                         __METHOD__,
3921                         array()
3922                 );
3923
3924                 if ( $dbr->numRows( $res ) > 0 ) {
3925                         foreach ( $res as $row ) {
3926                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3927                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3928                         }
3929                 }
3930                 return $data;
3931         }
3932
3933         /**
3934          * Get a tree of parent categories
3935          *
3936          * @param $children Array with the children in the keys, to check for circular refs
3937          * @return Array Tree of parent categories
3938          */
3939         public function getParentCategoryTree( $children = array() ) {
3940                 $stack = array();
3941                 $parents = $this->getParentCategories();
3942
3943                 if ( $parents ) {
3944                         foreach ( $parents as $parent => $current ) {
3945                                 if ( array_key_exists( $parent, $children ) ) {
3946                                         # Circular reference
3947                                         $stack[$parent] = array();
3948                                 } else {
3949                                         $nt = Title::newFromText( $parent );
3950                                         if ( $nt ) {
3951                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3952                                         }
3953                                 }
3954                         }
3955                 }
3956
3957                 return $stack;
3958         }
3959
3960         /**
3961          * Get an associative array for selecting this title from
3962          * the "page" table
3963          *
3964          * @return Array suitable for the $where parameter of DB::select()
3965          */
3966         public function pageCond() {
3967                 if ( $this->mArticleID > 0 ) {
3968                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3969                         return array( 'page_id' => $this->mArticleID );
3970                 } else {
3971                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3972                 }
3973         }
3974
3975         /**
3976          * Get the revision ID of the previous revision
3977          *
3978          * @param $revId Int Revision ID. Get the revision that was before this one.
3979          * @param $flags Int Title::GAID_FOR_UPDATE
3980          * @return Int|Bool Old revision ID, or FALSE if none exists
3981          */
3982         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3983                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3984                 $revId = $db->selectField( 'revision', 'rev_id',
3985                         array(
3986                                 'rev_page' => $this->getArticleID( $flags ),
3987                                 'rev_id < ' . intval( $revId )
3988                         ),
3989                         __METHOD__,
3990                         array( 'ORDER BY' => 'rev_id DESC' )
3991                 );
3992
3993                 if ( $revId === false ) {
3994                         return false;
3995                 } else {
3996                         return intval( $revId );
3997                 }
3998         }
3999
4000         /**
4001          * Get the revision ID of the next revision
4002          *
4003          * @param $revId Int Revision ID. Get the revision that was after this one.
4004          * @param $flags Int Title::GAID_FOR_UPDATE
4005          * @return Int|Bool Next revision ID, or FALSE if none exists
4006          */
4007         public function getNextRevisionID( $revId, $flags = 0 ) {
4008                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4009                 $revId = $db->selectField( 'revision', 'rev_id',
4010                         array(
4011                                 'rev_page' => $this->getArticleID( $flags ),
4012                                 'rev_id > ' . intval( $revId )
4013                         ),
4014                         __METHOD__,
4015                         array( 'ORDER BY' => 'rev_id' )
4016                 );
4017
4018                 if ( $revId === false ) {
4019                         return false;
4020                 } else {
4021                         return intval( $revId );
4022                 }
4023         }
4024
4025         /**
4026          * Get the first revision of the page
4027          *
4028          * @param $flags Int Title::GAID_FOR_UPDATE
4029          * @return Revision|Null if page doesn't exist
4030          */
4031         public function getFirstRevision( $flags = 0 ) {
4032                 $pageId = $this->getArticleID( $flags );
4033                 if ( $pageId ) {
4034                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4035                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4036                                 array( 'rev_page' => $pageId ),
4037                                 __METHOD__,
4038                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4039                         );
4040                         if ( $row ) {
4041                                 return new Revision( $row );
4042                         }
4043                 }
4044                 return null;
4045         }
4046
4047         /**
4048          * Get the oldest revision timestamp of this page
4049          *
4050          * @param $flags Int Title::GAID_FOR_UPDATE
4051          * @return String: MW timestamp
4052          */
4053         public function getEarliestRevTime( $flags = 0 ) {
4054                 $rev = $this->getFirstRevision( $flags );
4055                 return $rev ? $rev->getTimestamp() : null;
4056         }
4057
4058         /**
4059          * Check if this is a new page
4060          *
4061          * @return bool
4062          */
4063         public function isNewPage() {
4064                 $dbr = wfGetDB( DB_SLAVE );
4065                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4066         }
4067
4068         /**
4069          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4070          *
4071          * @return bool
4072          */
4073         public function isBigDeletion() {
4074                 global $wgDeleteRevisionsLimit;
4075
4076                 if ( !$wgDeleteRevisionsLimit ) {
4077                         return false;
4078                 }
4079
4080                 $revCount = $this->estimateRevisionCount();
4081                 return $revCount > $wgDeleteRevisionsLimit;
4082         }
4083
4084         /**
4085          * Get the  approximate revision count of this page.
4086          *
4087          * @return int
4088          */
4089         public function estimateRevisionCount() {
4090                 if ( !$this->exists() ) {
4091                         return 0;
4092                 }
4093
4094                 if ( $this->mEstimateRevisions === null ) {
4095                         $dbr = wfGetDB( DB_SLAVE );
4096                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4097                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4098                 }
4099
4100                 return $this->mEstimateRevisions;
4101         }
4102
4103         /**
4104          * Get the number of revisions between the given revision.
4105          * Used for diffs and other things that really need it.
4106          *
4107          * @param $old int|Revision Old revision or rev ID (first before range)
4108          * @param $new int|Revision New revision or rev ID (first after range)
4109          * @return Int Number of revisions between these revisions.
4110          */
4111         public function countRevisionsBetween( $old, $new ) {
4112                 if ( !( $old instanceof Revision ) ) {
4113                         $old = Revision::newFromTitle( $this, (int)$old );
4114                 }
4115                 if ( !( $new instanceof Revision ) ) {
4116                         $new = Revision::newFromTitle( $this, (int)$new );
4117                 }
4118                 if ( !$old || !$new ) {
4119                         return 0; // nothing to compare
4120                 }
4121                 $dbr = wfGetDB( DB_SLAVE );
4122                 return (int)$dbr->selectField( 'revision', 'count(*)',
4123                         array(
4124                                 'rev_page' => $this->getArticleID(),
4125                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4126                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4127                         ),
4128                         __METHOD__
4129                 );
4130         }
4131
4132         /**
4133          * Get the number of authors between the given revision IDs.
4134          * Used for diffs and other things that really need it.
4135          *
4136          * @param $old int|Revision Old revision or rev ID (first before range)
4137          * @param $new int|Revision New revision or rev ID (first after range)
4138          * @param $limit Int Maximum number of authors
4139          * @return Int Number of revision authors between these revisions.
4140          */
4141         public function countAuthorsBetween( $old, $new, $limit ) {
4142                 if ( !( $old instanceof Revision ) ) {
4143                         $old = Revision::newFromTitle( $this, (int)$old );
4144                 }
4145                 if ( !( $new instanceof Revision ) ) {
4146                         $new = Revision::newFromTitle( $this, (int)$new );
4147                 }
4148                 if ( !$old || !$new ) {
4149                         return 0; // nothing to compare
4150                 }
4151                 $dbr = wfGetDB( DB_SLAVE );
4152                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4153                         array(
4154                                 'rev_page' => $this->getArticleID(),
4155                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4156                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4157                         ), __METHOD__,
4158                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4159                 );
4160                 return (int)$dbr->numRows( $res );
4161         }
4162
4163         /**
4164          * Compare with another title.
4165          *
4166          * @param $title Title
4167          * @return Bool
4168          */
4169         public function equals( Title $title ) {
4170                 // Note: === is necessary for proper matching of number-like titles.
4171                 return $this->getInterwiki() === $title->getInterwiki()
4172                         && $this->getNamespace() == $title->getNamespace()
4173                         && $this->getDBkey() === $title->getDBkey();
4174         }
4175
4176         /**
4177          * Check if this title is a subpage of another title
4178          *
4179          * @param $title Title
4180          * @return Bool
4181          */
4182         public function isSubpageOf( Title $title ) {
4183                 return $this->getInterwiki() === $title->getInterwiki()
4184                         && $this->getNamespace() == $title->getNamespace()
4185                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4186         }
4187
4188         /**
4189          * Check if page exists.  For historical reasons, this function simply
4190          * checks for the existence of the title in the page table, and will
4191          * thus return false for interwiki links, special pages and the like.
4192          * If you want to know if a title can be meaningfully viewed, you should
4193          * probably call the isKnown() method instead.
4194          *
4195          * @return Bool
4196          */
4197         public function exists() {
4198                 return $this->getArticleID() != 0;
4199         }
4200
4201         /**
4202          * Should links to this title be shown as potentially viewable (i.e. as
4203          * "bluelinks"), even if there's no record by this title in the page
4204          * table?
4205          *
4206          * This function is semi-deprecated for public use, as well as somewhat
4207          * misleadingly named.  You probably just want to call isKnown(), which
4208          * calls this function internally.
4209          *
4210          * (ISSUE: Most of these checks are cheap, but the file existence check
4211          * can potentially be quite expensive.  Including it here fixes a lot of
4212          * existing code, but we might want to add an optional parameter to skip
4213          * it and any other expensive checks.)
4214          *
4215          * @return Bool
4216          */
4217         public function isAlwaysKnown() {
4218                 $isKnown = null;
4219
4220                 /**
4221                  * Allows overriding default behaviour for determining if a page exists.
4222                  * If $isKnown is kept as null, regular checks happen. If it's
4223                  * a boolean, this value is returned by the isKnown method.
4224                  *
4225                  * @since 1.20
4226                  *
4227                  * @param Title $title
4228                  * @param boolean|null $isKnown
4229                  */
4230                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4231
4232                 if ( !is_null( $isKnown ) ) {
4233                         return $isKnown;
4234                 }
4235
4236                 if ( $this->mInterwiki != '' ) {
4237                         return true;  // any interwiki link might be viewable, for all we know
4238                 }
4239
4240                 switch( $this->mNamespace ) {
4241                         case NS_MEDIA:
4242                         case NS_FILE:
4243                                 // file exists, possibly in a foreign repo
4244                                 return (bool)wfFindFile( $this );
4245                         case NS_SPECIAL:
4246                                 // valid special page
4247                                 return SpecialPageFactory::exists( $this->getDBkey() );
4248                         case NS_MAIN:
4249                                 // selflink, possibly with fragment
4250                                 return $this->mDbkeyform == '';
4251                         case NS_MEDIAWIKI:
4252                                 // known system message
4253                                 return $this->hasSourceText() !== false;
4254                         default:
4255                                 return false;
4256                 }
4257         }
4258
4259         /**
4260          * Does this title refer to a page that can (or might) be meaningfully
4261          * viewed?  In particular, this function may be used to determine if
4262          * links to the title should be rendered as "bluelinks" (as opposed to
4263          * "redlinks" to non-existent pages).
4264          * Adding something else to this function will cause inconsistency
4265          * since LinkHolderArray calls isAlwaysKnown() and does its own
4266          * page existence check.
4267          *
4268          * @return Bool
4269          */
4270         public function isKnown() {
4271                 return $this->isAlwaysKnown() || $this->exists();
4272         }
4273
4274         /**
4275          * Does this page have source text?
4276          *
4277          * @return Boolean
4278          */
4279         public function hasSourceText() {
4280                 if ( $this->exists() ) {
4281                         return true;
4282                 }
4283
4284                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4285                         // If the page doesn't exist but is a known system message, default
4286                         // message content will be displayed, same for language subpages-
4287                         // Use always content language to avoid loading hundreds of languages
4288                         // to get the link color.
4289                         global $wgContLang;
4290                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4291                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4292                         return $message->exists();
4293                 }
4294
4295                 return false;
4296         }
4297
4298         /**
4299          * Get the default message text or false if the message doesn't exist
4300          *
4301          * @return String or false
4302          */
4303         public function getDefaultMessageText() {
4304                 global $wgContLang;
4305
4306                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4307                         return false;
4308                 }
4309
4310                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4311                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4312
4313                 if ( $message->exists() ) {
4314                         return $message->plain();
4315                 } else {
4316                         return false;
4317                 }
4318         }
4319
4320         /**
4321          * Updates page_touched for this page; called from LinksUpdate.php
4322          *
4323          * @return Bool true if the update succeded
4324          */
4325         public function invalidateCache() {
4326                 if ( wfReadOnly() ) {
4327                         return false;
4328                 }
4329                 $dbw = wfGetDB( DB_MASTER );
4330                 $success = $dbw->update(
4331                         'page',
4332                         array( 'page_touched' => $dbw->timestamp() ),
4333                         $this->pageCond(),
4334                         __METHOD__
4335                 );
4336                 HTMLFileCache::clearFileCache( $this );
4337                 return $success;
4338         }
4339
4340         /**
4341          * Update page_touched timestamps and send squid purge messages for
4342          * pages linking to this title. May be sent to the job queue depending
4343          * on the number of links. Typically called on create and delete.
4344          */
4345         public function touchLinks() {
4346                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4347                 $u->doUpdate();
4348
4349                 if ( $this->getNamespace() == NS_CATEGORY ) {
4350                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4351                         $u->doUpdate();
4352                 }
4353         }
4354
4355         /**
4356          * Get the last touched timestamp
4357          *
4358          * @param $db DatabaseBase: optional db
4359          * @return String last-touched timestamp
4360          */
4361         public function getTouched( $db = null ) {
4362                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4363                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4364                 return $touched;
4365         }
4366
4367         /**
4368          * Get the timestamp when this page was updated since the user last saw it.
4369          *
4370          * @param $user User
4371          * @return String|Null
4372          */
4373         public function getNotificationTimestamp( $user = null ) {
4374                 global $wgUser, $wgShowUpdatedMarker;
4375                 // Assume current user if none given
4376                 if ( !$user ) {
4377                         $user = $wgUser;
4378                 }
4379                 // Check cache first
4380                 $uid = $user->getId();
4381                 // avoid isset here, as it'll return false for null entries
4382                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4383                         return $this->mNotificationTimestamp[$uid];
4384                 }
4385                 if ( !$uid || !$wgShowUpdatedMarker ) {
4386                         return $this->mNotificationTimestamp[$uid] = false;
4387                 }
4388                 // Don't cache too much!
4389                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4390                         $this->mNotificationTimestamp = array();
4391                 }
4392                 $dbr = wfGetDB( DB_SLAVE );
4393                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4394                         'wl_notificationtimestamp',
4395                         array(
4396                                 'wl_user' => $user->getId(),
4397                                 'wl_namespace' => $this->getNamespace(),
4398                                 'wl_title' => $this->getDBkey(),
4399                         ),
4400                         __METHOD__
4401                 );
4402                 return $this->mNotificationTimestamp[$uid];
4403         }
4404
4405         /**
4406          * Generate strings used for xml 'id' names in monobook tabs
4407          *
4408          * @param $prepend string defaults to 'nstab-'
4409          * @return String XML 'id' name
4410          */
4411         public function getNamespaceKey( $prepend = 'nstab-' ) {
4412                 global $wgContLang;
4413                 // Gets the subject namespace if this title
4414                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4415                 // Checks if cononical namespace name exists for namespace
4416                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4417                         // Uses canonical namespace name
4418                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4419                 } else {
4420                         // Uses text of namespace
4421                         $namespaceKey = $this->getSubjectNsText();
4422                 }
4423                 // Makes namespace key lowercase
4424                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4425                 // Uses main
4426                 if ( $namespaceKey == '' ) {
4427                         $namespaceKey = 'main';
4428                 }
4429                 // Changes file to image for backwards compatibility
4430                 if ( $namespaceKey == 'file' ) {
4431                         $namespaceKey = 'image';
4432                 }
4433                 return $prepend . $namespaceKey;
4434         }
4435
4436         /**
4437          * Get all extant redirects to this Title
4438          *
4439          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4440          * @return Array of Title redirects to this title
4441          */
4442         public function getRedirectsHere( $ns = null ) {
4443                 $redirs = array();
4444
4445                 $dbr = wfGetDB( DB_SLAVE );
4446                 $where = array(
4447                         'rd_namespace' => $this->getNamespace(),
4448                         'rd_title' => $this->getDBkey(),
4449                         'rd_from = page_id'
4450                 );
4451                 if ( !is_null( $ns ) ) {
4452                         $where['page_namespace'] = $ns;
4453                 }
4454
4455                 $res = $dbr->select(
4456                         array( 'redirect', 'page' ),
4457                         array( 'page_namespace', 'page_title' ),
4458                         $where,
4459                         __METHOD__
4460                 );
4461
4462                 foreach ( $res as $row ) {
4463                         $redirs[] = self::newFromRow( $row );
4464                 }
4465                 return $redirs;
4466         }
4467
4468         /**
4469          * Check if this Title is a valid redirect target
4470          *
4471          * @return Bool
4472          */
4473         public function isValidRedirectTarget() {
4474                 global $wgInvalidRedirectTargets;
4475
4476                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4477                 if ( $this->isSpecial( 'Userlogout' ) ) {
4478                         return false;
4479                 }
4480
4481                 foreach ( $wgInvalidRedirectTargets as $target ) {
4482                         if ( $this->isSpecial( $target ) ) {
4483                                 return false;
4484                         }
4485                 }
4486
4487                 return true;
4488         }
4489
4490         /**
4491          * Get a backlink cache object
4492          *
4493          * @return BacklinkCache
4494          */
4495         function getBacklinkCache() {
4496                 if ( is_null( $this->mBacklinkCache ) ) {
4497                         $this->mBacklinkCache = new BacklinkCache( $this );
4498                 }
4499                 return $this->mBacklinkCache;
4500         }
4501
4502         /**
4503          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4504          *
4505          * @return Boolean
4506          */
4507         public function canUseNoindex() {
4508                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4509
4510                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4511                         ? $wgContentNamespaces
4512                         : $wgExemptFromUserRobotsControl;
4513
4514                 return !in_array( $this->mNamespace, $bannedNamespaces );
4515
4516         }
4517
4518         /**
4519          * Returns the raw sort key to be used for categories, with the specified
4520          * prefix.  This will be fed to Collation::getSortKey() to get a
4521          * binary sortkey that can be used for actual sorting.
4522          *
4523          * @param $prefix string The prefix to be used, specified using
4524          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4525          *   prefix.
4526          * @return string
4527          */
4528         public function getCategorySortkey( $prefix = '' ) {
4529                 $unprefixed = $this->getText();
4530
4531                 // Anything that uses this hook should only depend
4532                 // on the Title object passed in, and should probably
4533                 // tell the users to run updateCollations.php --force
4534                 // in order to re-sort existing category relations.
4535                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4536                 if ( $prefix !== '' ) {
4537                         # Separate with a line feed, so the unprefixed part is only used as
4538                         # a tiebreaker when two pages have the exact same prefix.
4539                         # In UCA, tab is the only character that can sort above LF
4540                         # so we strip both of them from the original prefix.
4541                         $prefix = strtr( $prefix, "\n\t", '  ' );
4542                         return "$prefix\n$unprefixed";
4543                 }
4544                 return $unprefixed;
4545         }
4546
4547         /**
4548          * Get the language in which the content of this page is written.
4549          * Defaults to $wgContLang, but in certain cases it can be e.g.
4550          * $wgLang (such as special pages, which are in the user language).
4551          *
4552          * @since 1.18
4553          * @return Language
4554          */
4555         public function getPageLanguage() {
4556                 global $wgLang;
4557                 if ( $this->isSpecialPage() ) {
4558                         // special pages are in the user language
4559                         return $wgLang;
4560                 } elseif ( $this->isCssOrJsPage() || $this->isCssJsSubpage() ) {
4561                         // css/js should always be LTR and is, in fact, English
4562                         return wfGetLangObj( 'en' );
4563                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4564                         // Parse mediawiki messages with correct target language
4565                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4566                         return wfGetLangObj( $lang );
4567                 }
4568                 global $wgContLang;
4569                 // If nothing special, it should be in the wiki content language
4570                 $pageLang = $wgContLang;
4571                 // Hook at the end because we don't want to override the above stuff
4572                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4573                 return wfGetLangObj( $pageLang );
4574         }
4575 }